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Respiratory kinematics by optoelectronic analysis of chest-wall motion and ultrasonic imaging of the diaphragm
NASA Astrophysics Data System (ADS)
Aliverti, Andrea; Pedotti, Antonio; Ferrigno, Giancarlo; Macklem, P. T.
Although from a respiratory point of view, compartmental volume change or lack of it is the most crucial variable, it has not been possible to measure the volume of chest wall compartments directly. Recently we developed a new method based on a optoelectronic motion analyzer that can give the three-dimensional location of many markers with the temporal and spatial accuracy required for respiratory measurements. Marker's configuration has been designed specifically to measure the volume of three chest wall compartments, the pulmonary and abdominal rib cage compartments and the abdomen, directly. However, it can not track the exact border between the two rib cage compartments (pulmonary and abdominal) which is determined by the cephalic extremity of the area of apposition of the diaphragm to the inner surface of the rib cage, and which can change systematically as a result of disease processes. The diaphragm displacement can be detected by ultrasonography. In the present study, we propose an integrated system able to investigate the relationships between external (chest wall) and internal (diaphragm) movements of the different respiratory structures by simultaneous external imaging with the optoelectronic system combined with internal kinematic imaging using ultrasounds. 2D digitized points belonging to the lower lung margin, taken from ultrasonographic views, are mapped into the 3D space, where chest wall markers are acquired. Results are shown in terms of accuracy of 3D probe location, relative movement between the probe and the body landmarks, dynamic relationships between chest wall volume and position of the diaphragm during quiet breathing, slow inspirations, relaxations and exercise.
The DDBD Method In The A-Seismic Design of Anchored Diaphragm Walls
Manuela, Cecconi; Vincenzo, Pane; Sara, Vecchietti
The development of displacement based approaches for earthquake engineering design appears to be very useful and capable to provide improved reliability by directly comparing computed response and expected structural performance. In particular, the design procedure known as the Direct Displacement Based Design (DDBD) method, which has been developed in structural engineering over the past ten years in the attempt to mitigate some of the deficiencies in current force-based design methods, has been shown to be very effective and promising ([1], [2]). The first attempts of application of the procedure to geotechnical engineering and, in particular, earth retaining structures are discussed in [3], [4] and [5]. However in this field, the outcomes of the research need to be further investigated in many aspects. The paper focuses on the application of the DDBD method to anchored diaphragm walls. The results of the DDBD method are discussed in detail in the paper, and compared to those obtained from conventional pseudo-static analyses.
A minimally invasive technique for stabilizing the diaphragm on the thoracic wall after blunt chest trauma: the "lifting-up method".
Kamiyoshihara, Mitsuhiro; Igai, Hitoshi; Kawatani, Natsuko; Ibe, Takashi
Most traumatic diaphragmatic tears are located centrally or radially and may be amenable to repair by direct suturing or suturing with a surgical patch. However, diaphragmatic tears, such as those immediately adjacent to the costal margin, are uncommon. We describe how we repaired this type of tear using a needle loop retractor to pass a 2-0 braided suture through the chest wall on both sides of the rib to suture the torn diaphragm to the chest wall. Our technique is more physiologically and anatomically consistent than previously reported techniques. We have termed this technique the "lifting-up method", which we believe to be an easy and useful technique for repairing traumatic diaphragmatic injuries with no seam allowance. PMID:26391998
Celebi, M.; Brady, G.; Safak, E.; Converse, A.
The objective of this paper is to study the earthquake performance of the roof diaphragm of the West Valley College gymnasium in Saratoga, California through a complete set of acceleration records obtained during the 24 April 1984 Morgan Hill Earthquake (M equals 6. 1). The roof diaphragm of the 112 ft. multiplied by 144 ft. rectangular, symmetric gymnasium consists of 3/8 in. plywood over tongue-and-groove sheathing attached to steel trusses supported by reinforced concrete columns and walls. Three sensors placed in the direction of each of the axes of the diaphragm facilitate the evaluation of in-plane deformation of the diaphragm. Other sensors placed at ground level measure vertical and horizontal motion of the building floor, and consequently allow the calculation of the relative motion of the diaphragm with respect to the ground level.
[Curative en-bloc resection (lung, diaphragm, liver, adrenal gland and thoracic wall) for echinococcus multilocularis. Report of an unusual disease course].
Lampl, L; Hamperl, W D
Report concerning an en-bloc-resection of right lower lobe of the lung, diaphragm, right lobe of the liver, right adrenal gland, parts of the chestwall and a fistula for alveolar echinococcus. Combined postoperative treatment with mebendazol. More than 4 years postoperatively no evidence of a recurrency. PMID:1583984
Metallic positive expulsion diaphragms
NASA Technical Reports Server (NTRS)
Gleich, D.
High-cycle life ring-reinforced hemispherical type positive expulsion diaphragm performance was demonstrated by room temperature fluid expulsion tests of 13" diameter, 8 mil thick stainless steel configurations. A maximum of eleven (11) leak-free, fluid expulsions were achieved by a 25 deg cone angle diaphragm hoop-reinforced with .110-inch cross-sectional diameter wires. This represents a 70% improvement in diaphragm reversal cycle life compared to results previously obtained. The reversal tests confirmed analytic predictions for diaphragm cycle life increases due to increasing values of diaphragm cone angle, radius to thickness ratio and material strain to necking capacity. Practical fabrication techniques were demonstrated for forming close-tolerance, thin corrugated shells and for obtaining closely controlled reinforcing ring stiffness required to maximize diaphragm cycle life. A non-destructive inspection technique for monitoring large local shell bending strains was developed.
Nonmetallic Diaphragms for Instruments
NASA Technical Reports Server (NTRS)
Eaton, H N; Buckingham, C T
This report, the second of a series of reports relating to the general subject of instrument diaphragms. The first report of the series was published as Technical Report no. 165, "diaphragms for aeronautic instruments," and comprised an outline of historical developments and theoretical principles. The present report relates entirely to nonmetallic diaphragms, the use of which in certain types of pressure elements has been increasing for some time. Little, if any, information has been available to aid the designer of instruments using this form of pressure element. It was to attempt to meet the need for such information that the investigation reported in this paper was undertaken. The report describes the various materials which have been used as nonmetallic diaphragms, discusses the factors which affect the performance of the diaphragms and gives the results of tests made for the purpose of investigating the effect produced by these factors.
Pressure activated diaphragm bonder
Evans, L.B.; Malba, V.
A device is available for bonding one component to another, particularly for bonding electronic components of integrated circuits, such as chips, to a substrate. The bonder device in one embodiment includes a bottom metal block having a machined opening wherein a substrate is located, a template having machined openings which match solder patterns on the substrate, a thin diaphragm placed over the template after the chips have been positioned in the openings therein, and a top metal block positioned over the diaphragm and secured to the bottom block, with the diaphragm retained therebetween. The top block includes a countersink portion which extends over at least the area of the template and an opening through which a high pressure inert gas is supplied to exert uniform pressure distribution over the diaphragm to keep the chips in place during soldering. A heating means is provided to melt the solder patterns on the substrate and thereby solder the chips thereto. 4 figs.
Pressure activated diaphragm bonder
Evans, Leland B.; Malba, Vincent
A device is available for bonding one component to another, particularly for bonding electronic components of integrated circuits, such as chips, to a substrate. The bonder device in one embodiment includes a bottom metal block having a machined opening wherein a substrate is located, a template having machined openings which match solder patterns on the substrate, a thin diaphragm placed over the template after the chips have been positioned in the openings therein, and a top metal block positioned over the diaphragm and secured to the bottom block, with the diaphragm retained therebetween. The top block includes a countersink portion which extends over at least the area of the template and an opening through which a high pressure inert gas is supplied to exert uniform pressure distribution over the diaphragm to keep the chips in place during soldering. A heating means is provided to melt the solder patterns on the substrate and thereby solder the chips thereto.
Burst diaphragm sequence valve
NASA Astrophysics Data System (ADS)
Wisneskie, Bradley D.; Hyman, Sheldon; Hallum, Charles E.
A burst diaphragm sequence valve which effectively combines the structure of a burst diaphragm with that of an ordinary swing check valve, the pivot of the ordinary swing check valve being replaced by an integral flexural hinge. The sequence valve provides a way to sequentially burn solid propellant hot gas generators which exit into a common gas manifold, thereby enabling gas-powered devices to operate for a longer time than the duration of one gas generator burn.
Diaphragm pacing: the state of the art
Legras, Antoine; Arame, Alex; Pricopi, Ciprian; Boucherie, Jean-Claude; Badia, Alain; Panzini, Capucine Morelot
Diaphragm pacing (DP) is an orphan surgical procedure that may be proposed in strictly selected ventilator-dependent patients to get an active diaphragm contraction. The goal is to wean from mechanical ventilation (MV) and restore permanent efficient breathing. The two validated indications, despite the lack of randomised control trials, concern patients with high-level spinal cord injuries (SCI) and central hypoventilation syndromes (CHS). To date, two different techniques exist. The first, intrathoracic diaphragm pacing (IT-DP), based on a radiofrequency method, in which the electrodes are directly placed around the phrenic nerve. The second, intraperitoneal diaphragm pacing (IP-DP) uses intradiaphragmatic electrodes implanted through laparoscopy. In both techniques, the phrenic nerves must be intact and diaphragm reconditioning is always required after implantation. No perioperative mortality has been reported and ventilator-weaning rate is about 72% to 96% in both techniques. Improvement of quality of life, by restoring a more physiological breathing, has been almost constant in patients that could be weaned. Failure or delay in recovery of effective diaphragm contractions could be due to irreversible amyotrophy or chest wall damage. Recent works have evaluated the interest of IP-DP in amyotrophic lateral sclerosis (ALS). After some short series were reported in the literature, the only multicentric randomized study including 74 ALS patients was prematurely stopped because of excessive mortality in paced patients. Then, another trial analysed the place of IP-DP in peripheral diaphragm dysfunction but, given the multiple biases, the published results cannot validate that indication. Reviewing all available literature as in our experience, shows that DP is an effective method to wean selected patients dependent on ventilator and improve their daily life. Other potential indications will have to be evaluated by randomised control trials. PMID:27195135
Diaphragm pacing: the state of the art.
Le Pimpec-Barthes, Francoise; Legras, Antoine; Arame, Alex; Pricopi, Ciprian; Boucherie, Jean-Claude; Badia, Alain; Panzini, Capucine Morelot
Diaphragm pacing (DP) is an orphan surgical procedure that may be proposed in strictly selected ventilator-dependent patients to get an active diaphragm contraction. The goal is to wean from mechanical ventilation (MV) and restore permanent efficient breathing. The two validated indications, despite the lack of randomised control trials, concern patients with high-level spinal cord injuries (SCI) and central hypoventilation syndromes (CHS). To date, two different techniques exist. The first, intrathoracic diaphragm pacing (IT-DP), based on a radiofrequency method, in which the electrodes are directly placed around the phrenic nerve. The second, intraperitoneal diaphragm pacing (IP-DP) uses intradiaphragmatic electrodes implanted through laparoscopy. In both techniques, the phrenic nerves must be intact and diaphragm reconditioning is always required after implantation. No perioperative mortality has been reported and ventilator-weaning rate is about 72% to 96% in both techniques. Improvement of quality of life, by restoring a more physiological breathing, has been almost constant in patients that could be weaned. Failure or delay in recovery of effective diaphragm contractions could be due to irreversible amyotrophy or chest wall damage. Recent works have evaluated the interest of IP-DP in amyotrophic lateral sclerosis (ALS). After some short series were reported in the literature, the only multicentric randomized study including 74 ALS patients was prematurely stopped because of excessive mortality in paced patients. Then, another trial analysed the place of IP-DP in peripheral diaphragm dysfunction but, given the multiple biases, the published results cannot validate that indication. Reviewing all available literature as in our experience, shows that DP is an effective method to wean selected patients dependent on ventilator and improve their daily life. Other potential indications will have to be evaluated by randomised control trials. PMID:27195135
Active Piezoelectric Diaphragms
NASA Technical Reports Server (NTRS)
Bryant, Robert G.; Effinger, Robert T., IV; Aranda, Isaiah, Jr.; Copeland, Ben M.; Covington, Ed W., III
Several active piezoelectric diaphragms were fabricated by placing unelectroded piezoelectric disks between copper clad films patterned with Inter-Circulating Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is radially distributed electric field that mechanically strains the piezo-ceramic along the Z-axis (perpendicular to the applied electric field), rather than the expected in-plane (XY-axis) direction. Unlike other out of plane piezoelectric actuators, which are benders, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements while maintaining a constant circumference. This paper covers the fabrication and characterization of these diaphragms as a function of poling field strength, ceramic diameter and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage ranging from DC to 10 Hz.
Diaphragms for Aeronautic Instruments
NASA Technical Reports Server (NTRS)
Hersey, M D
This investigation was carried out at the request of the National Advisory Committee for Aeronautics and comprises an outline of historical developments and theoretical principles, together with a discussion of expedients for making the most effective use of existing diaphragms actuated by the hydrostatic pressure form an essential element of a great variety instruments for aeronautic and other technical purposes. The various physical data needed as a foundation for rational methods of diaphragm design have not, however, been available hitherto except in the most fragmentary form.
Materials for Slack Diaphragms
NASA Technical Reports Server (NTRS)
Puschmann, Traute
This report deals with systematic experiments carried out on five diaphragm materials with different pretreatment, for the purpose of ascertaining the suitability of such materials for slack diaphragms. The relationship of deflection and load, temperature and moisture, was recorded. Of the explored materials, synthetic leather, balloon cloth, goldbeaters skin, Igelit and Buna, synthetic leather treated with castor oil is the most suitable material for the small pressure range required. Balloon cloth is nearly as good, while goldbeaters skin, Igelit and Buna were found to be below the required standards.
Inertia diaphragm pressure transducer
NASA Technical Reports Server (NTRS)
Seegmiller, H. L. B.
Transducer measures gas pressure profiles in high temperature, short duration, gas flows usually found in devices where pressure pulses may have durations of few microseconds to several milliseconds. Assembly includes fluid delay line, delay chamber, and flow restrictor for equalizing steady state pressure on diaphragm's sides
NASA Astrophysics Data System (ADS)
Shelley, Richard; Ross, William L., Sr.
The Auxiliary Power Unit (APU) fuel (hydrazine) tanks were removed from the Columbia Shuttle during major modification of the vehicle, because of long-term hydrazine compatibility concerns. The three tanks had been in service for 11 years. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal casing from one of the APU tanks was required. NASA Johnson Space Center Propulsion and Power Division requested the NASA Johnson Space Center White Sands Test Facility to examine the EPR diaphragm for signs of degradation that might limit the life of its function in the APU tank and to examine the metal casing for signs of surface corrosion. No appreciable degradation of the EPR diaphragm was noted. A decrease in the tensile properties was found, but tensile failure is considered unlikely because the metal casing constrains the diaphragm, preventing it from elongating more than a few percent. The titanium casing showed no evidence of surface corrosion.
NASA Technical Reports Server (NTRS)
Shelley, Richard; Ross, William L., Sr.
The Auxiliary Power Unit (APU) fuel (hydrazine) tanks were removed from the Columbia Shuttle during major modification of the vehicle, because of long-term hydrazine compatibility concerns. The three tanks had been in service for 11 years. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal casing from one of the APU tanks was required. NASA Johnson Space Center Propulsion and Power Division requested the NASA Johnson Space Center White Sands Test Facility to examine the EPR diaphragm for signs of degradation that might limit the life of its function in the APU tank and to examine the metal casing for signs of surface corrosion. No appreciable degradation of the EPR diaphragm was noted. A decrease in the tensile properties was found, but tensile failure is considered unlikely because the metal casing constrains the diaphragm, preventing it from elongating more than a few percent. The titanium casing showed no evidence of surface corrosion.
Scalzo, A.
This patent describes, in a combustion turbine having a casing, one or more slots of a first predetermined cross-section formed circumferentially within the casing at a compressor portion of the turbine, and a compressor diaphragm assembly adapted to be suspended from each of the one or more slots to provide a labyrinth seal with a plurality of compressor discs, a method of forming each compressor diaphragm assembly. It comprises: providing a plurality of vane airfoils each of which have an inner shroud formed integrally with the vane airfoil, and an outer portion attached to the vane airfoil; providing outer ring means for suspending each of the plurality of van airfoils at a stagger angle; suspending the plurality of vane airfoils from the outer ring means, thereby disposing each the vane airfoil and its respective outer portion at the stagger angle; and providing seal carrier means for engagement with each the inner shroud.
Radial Field Piezoelectric Diaphragms
NASA Technical Reports Server (NTRS)
Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.
A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.
Flexible Sandwich Diaphragms Are Less Permeable
NASA Technical Reports Server (NTRS)
Michalovic, John G.; Vassallo, Franklin A.
Diaphragms for use in refrigerator compressors made as laminates of commercially available elastomers and metals. Diaphragms flexible, but less permeable by chlorofluorocarbon refrigerant fluids than diaphragms made of homogeneous mixtures of materials.
Birth Control: How to Use Your Diaphragm
... creams (such as Monistat). These can make tiny holes in the diaphragm. Inserting Your Diaphragm You can ... and out. Be careful not to tear a hole in the diaphragm with your fingernails. You should ...
Novel diaphragm based Stirling cryocooler
NASA Astrophysics Data System (ADS)
Caughley, Alan; Tucker, Alan; Gschwendtner, Michael; Sellier, Mathieu
Industrial Research Ltd has developed a unique diaphragm-based pressure wave generator technology for employment in pulse tube and Stirling cryocoolers. The system uses a pair of metal diaphragms to separate the clean cryocooler gas circuit from a conventionally lubricated mechanical driver, thus producing a clean pressure wave with a long-life drive. We have now extended the same diaphragm concept to support and seal the displacer in a free piston Stirling expander. The diaphragms allow displacer movement without rubbing or clearance gap seals, hence allowing for the development of costeffective long-life and efficient Stirling cryocoolers. Initial modeling, operating in conjunction with a 200 cc swept volume pressure wave generator, predicted in excess of 300 W cooling at 77 K with a Carnot efficiency of over 25%. A proof-of-concept prototype has achieved cryogenic temperatures. Details of the concept, modeling, and testing will be presented.
Effects of muscle-to-electrode distance on the human diaphragm electromyogram.
Beck, J; Sinderby, C; Weinberg, J; Grassino, A
It has been suggested that esophageal recordings of the diaphragm electromyogram (EMGdi) are influenced by changes in chest wall configuration. Whether the changes are of physiological or artifactual origin is unclear. For example, the distance between the esophageal electrode and the diaphragm is likely to alter with chest wall configuration and may lead to misinterpretations of EMGdi. The aims of this study were 1) to evaluate and quantify the effect of the muscle-to-electrode (ME) distance filter on EMGdi, as obtained with a multiple-array esophageal electrode, 2) to take advantage of the ME distance filter to locate the position of the diaphragm with respect to the electrode, and 3) to evaluate the influence of lung volume and chest wall configuration on EMGdi center frequency (CF) while controlling for the ME distance filter and signal quality. Five subjects performed six static contractions of the diaphragm at each of seven chest wall configurations, as evaluated by the method of K. Konno and J. Mead (J. Appl. Physiol. 22: 407-422, 1967). EMGdi was measured with seven pairs of electrodes mounted on an esophageal catheter. The pair of electrodes whose EMGdi power spectra were the least filtered by the ME distance was assumed to be closest to the diaphragm. The results of the study indicated that 1) EMGdi power spectra were strongly affected by the distance between the diaphragm and the electrodes. CF decreased by approximately 1 Hz/mm displacement away from the electrode pair closest to the diaphragm; and 2) no systematic relationship was found between changes in chest wall configuration and CF, when CF was measured from the electrode pair closest to the diaphragm. We conclude that the EMGdi CF can be reliably measured with a multiple-array esophageal electrode that covers the span of diaphragmatic excursion and by selecting the pair of electrodes that is the closest to the diaphragm. PMID:8567542
Miniature electrically operated diaphragm valve
Adkins, Douglas R.; Spletzer, Barry L.; Wong, Chungnin C.; Frye-Mason, Gregory C.; Fischer, Gary J.; Hesketh, Peter J.
The present invention provides a miniature electrically operated valve that can stand off significant pressures, that can be inexpensively produced, and that can be made to operate without continuous electrical power. A valve according to the present invention comprises a housing and a beam mounted with the housing. A diaphragm mounted with the housing forms a sealed fluid volume. An electromagnetic energy source, such as an electromagnetic coil, mounts with the housing and when energized urges the beam in one direction. The beam can be urged in the opposing direction by passive means or by reversing the polarity of the electromagnetic energy source or by a second electromagnetic energy source. Two fluid ports mount with the housing. A first fluid port mounts so that, as the beam is urged in one direction or the opposite, the beam urges the diaphragm to move between engaging and substantially sealing the fluid port and disengaging and not substantially sealing the fluid port. A seat can be mounted with the diaphragm to aid in sealing the fluid port. Latching mechanisms such as permanent magnets can be mounted so that the valve remains in the open or closed positions without continuous electrical power input. Fluid can flow through the housing between the two fluid ports when the diaphragm does not seal the first fluid port, but can be prevented from flowing by urging the beam so that the diaphragm seals the first fluid port. Various embodiments accommodate various latching mechanisms, electromagnetic energy sources, number of fluid ports, and diaphragm design considerations.
APU diaphragm testing. Test plan
NASA Astrophysics Data System (ADS)
Shelley, Richard
Auxiliary Power Unit (APU) fuel (hydrazine) tanks have had to be removed from the Columbia Shuttle (OV-102) because they have been in service for 11 years, which is the limit of their useful life. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal from one of the APU tanks is required. The JSC Propulsion and Power Division has requested White Sands Test Facility (WSTF) to examine the EPR diaphragm thoroughly and the metal casing generally from one tank. The objective is to examine the EPR diaphragm for signs of degradation that may limit the life of its function in the APU propellant tank. The metal casing will also be examined for signs of surface corrosion.
Active diaphragm rupture with laser beam irradiation
NASA Astrophysics Data System (ADS)
Takahashi, T.; Torikai, H.; Yang, Q. S.; Watanabe, K.; Sasoh, A.
We performed shock tube operations with a layer of diaphragm being ruptured by laser beam irradiation. Mylar or Cellophane was examined as the diaphragm material. It has been demonstrated that shock tube can be operated with this new technique. The absorbed energy depends on the material and thickness of the diaphragm and is an important control parameter.
Diaphragm recruitment during nonrespiratory activities.
Al-Bilbeisi, F; McCOOL, F D
We previously found that weight lifters could generate greater inspiratory pressures and had more diaphragm mass than control subjects. We postulated that the weight-lifting activity itself provided a strength-training stimulus to the diaphragm. To evaluate the extent to which the diaphragm is recruited during strenuous nonrespiratory activities, we measured transdiaphragmatic pressure (Pdi) in six healthy subjects during biceps curls, bench press, power lift, and sit-ups. Each maneuver was performed with and without added weight (control), and with and without an abdominal binder. The weighted maneuvers were performed either during inspiration or expiration. Maximal static transdiaphragmatic pressure (Pdi(max)) was measured during a combined inspiratory and expulsive maneuver. Group mean values of Pdi increased during all activities when compared with control (57 +/- 24 versus 18 +/- 10 cm H(2)O [mean +/- SD] [p < 0.001]), as task intensity increased (98 +/- 14 versus 35 +/- 13 cm H(2)O for high- and low-intensity activities, respectively) (p < 0.001), and with abdominal binding (75 +/- 25 versus 59 +/- 25 cm H(2)O) (p < 0.05). Peak levels of Pdi attained during the activities were 126 +/- 11 cm H(2)O or 0.65 +/- 0.09 of Pdi(max). Changes in gastric pressure accounted for 85 +/- 4% of the increase in Pdi during the activities whereas it accounted for only 58 +/- 9% of the rise in Pdi during the control activities (p < 0.001). We conclude that during a range of weight-lifting activities, the diaphragm is recruited and Pdi is raised to a level that may provide a significant strength-training stimulus to the diaphragm. PMID:10934070
Inflammatory pseudotumor of the diaphragm.
Höer, J; Steinau, G; Füzesi, L; Gunawan, B; Schumpelick, V
A 5-year-old-boy presented with a right pleural effusion and fever. A tumorous mass was located between the right lung and the liver. The boy underwent a right thoracotomy with excision of the tumor and the adherent parts of the right hemidiaphragm. Histology and immunohistochemistry showed an inflammatory pseudotumor of the diaphragm. This is the first reported case of an inflammatory pseudotumor in this location. A brief review of the heterogeneous theories about the pathogenesis and the different therapeutic regimens for this rare neoplastic entity are discussed. PMID:10415294
... a dome-shaped bowl made of thin, flexible rubber that sits over the cervix. How Does It ... or baby oil. These substances can cause the rubber to become brittle and crack. Other vaginal creams, ...
Electrically heated diaphragm eliminates use of pyrotechnics
NASA Technical Reports Server (NTRS)
Mathewson, R. C.
Membrane-type diaphragm is used in systems where fluids are contained under pressure until a certain pressure threshold or point of time has been reached when the fluids are automatically released. The diaphragm is resistance heated until its strength is degraded to the point of rupture, thus releasing the contained fluids.
Radial-Electric-Field Piezoelectric Diaphragm Pumps
NASA Technical Reports Server (NTRS)
Bryant, Robert G.; Working, Dennis C.; Mossi, Karla; Castro, Nicholas D.; Mane, Pooma
In a recently invented class of piezoelectric diaphragm pumps, the electrode patterns on the piezoelectric diaphragms are configured so that the electric fields in the diaphragms have symmetrical radial (along-the-surface) components in addition to through-the-thickness components. Previously, it was accepted in the piezoelectric-transducer art that in order to produce the out-of-plane bending displacement of a diaphragm needed for pumping, one must make the electric field asymmetrical through the thickness, typically by means of electrodes placed on only one side of the piezoelectric material. In the present invention, electrodes are placed on both sides and patterned so as to produce substantial radial as well as through-the-thickness components. Moreover, unlike in the prior art, the electric field can be symmetrical through the thickness. Tests have shown in a given diaphragm that an electrode configuration according to this invention produces more displacement than does a conventional one-sided electrode pattern. The invention admits of numerous variations characterized by various degrees of complexity. Figure 1 is a simplified depiction of a basic version. As in other piezoelectric diaphragm pumps of similar basic design, the prime mover is a piezoelectric diaphragm. Application of a suitable voltage to the electrodes on the diaphragm causes it to undergo out-of-plane bending. The bending displacement pushes a fluid out of, or pulls the fluid into, a chamber bounded partly by the diaphragm. Also as in other diaphragm pumps in general, check valves ensure that the fluid flows only in through one port and only out through another port.
Diaphragm: A vital respiratory muscle in mammals.
Lessa, Thais Borges; de Abreu, Dilayla Kelly; Bertassoli, Bruno Machado; Ambrósio, Carlos Eduardo
The diaphragm is a respiratory muscle that is primarily responsible for the respiratory function in normal individuals. In mammals, the diaphragm muscle has been studied from the early days of zoology, comparative and experimental anatomy, physiology, medicine, physics, and philosophy. However, even with these early advances in knowledge pertaining to the diaphragm, comprehensive morphological data on the diaphragm are still incomplete. In this review, we summarize the beginnings of the morphological description of the diaphragm, and we describe the current status of the known morphological and embryological features. In addition, we correlate how the impairment of the diaphragm muscle in Duchenne muscular dystrophy (DMD) can lead to patient deaths. DMD is the most common X-linked muscle degenerative disease and is caused by a lack of dystrophin protein. Dystrophin is an important muscle protein that links the cellular cytoskeleton with the extracellular matrix. In the absence of dystrophin, the muscle becomes susceptible to damage during muscle contraction. This review allows researchers to obtain an overview of the diaphragm, transcending the morphological data from animals described in conventional literature. PMID:27045597
Difficult to wean: think of the diaphragm.
Suryanarayana, Jandhyala; Varma, Muralidhar; Vidyasagar, Sudha; Vivek, Ganapathiraman
A 65-year-old woman, treated for non-ST segment elevation myocardial infarction and unexplained type 2 respiratory failure, was referred to our hospital in view of difficulty in weaning off the ventilator. She was evaluated in detail for persistent hypercapnia. Ultrasound of the diaphragm showed minimal excursion of diaphragm while she was off the ventilator and fluoroscopy confirmed bilateral diaphragmatic palsy. As extensive radiological, immunological and microbiological workup ruled out other possible aetiologies, a diagnosis of idiopathic Bell's palsy of the diaphragm was made. She was treated with valacyclovir and steroids after which she gradually recovered and was weaned off the ventilator. PMID:24473427
Action of the diaphragm on the rib cage.
Troyer, André De; Wilson, Theodore A
When the diaphragm contracts, pleural pressure falls, exerting a caudal and inward force on the entire rib cage. However, the diaphragm also exerts forces in the cranial and outward direction on the lower ribs. One of these forces, the "insertional force," is applied by the muscle at its attachments to the lower ribs. The second, the "appositional force," is due to the transmission of abdominal pressure to the lower rib cage in the zone of apposition. In the control condition at functional residual capacity, the effects of these two forces on the lower ribs are nearly equal and outweigh the effect of pleural pressure, whereas for the upper ribs, the effect of pleural pressure is greater. The balance between these effects, however, may be altered. When the abdomen is given a mechanical support, the insertional and appositional forces are increased, so that the muscle produces a larger expansion of the lower rib cage and, with it, a smaller retraction of the upper rib cage. In contrast, at higher lung volumes the zone of apposition is decreased, and pleural pressure is the dominant force on the lower ribs as well. Consequently, although the force exerted by the diaphragm on these ribs remains inspiratory, rib displacement is reversed into a caudal-inward displacement. This mechanism likely explains the inspiratory retraction of the lateral walls of the lower rib cage observed in many subjects with chronic obstructive pulmonary disease (Hoover's sign). These observations support the use of a three-compartment, rather than a two-compartment, model to describe chest wall mechanics. PMID:27283911
Flexible diaphragm-extreme temperature usage
NASA Technical Reports Server (NTRS)
Lerma, Guillermo (Inventor)
A diaphragm suitable for extreme temperature usage, such as encountered in critical aerospace applications, is fabricated by a unique method, and of a unique combination of materials. The materials include multilayered lay-ups of diaphragm materials sandwiched between layers of bleeder fabrics. After being formed in the desired shape on a mold, they are vacuum sealed and then cured under pressure, in a heated autoclave. A bond capable of withstanding extreme temperatures are produced.
[Traumatic Injury of the Diaphragm].
Kadokura, Mitsutaka
Traumatic diaphragmatic injury (TDI) is relatively rare condition, and is associated with high rates of morbidity and mortality. TDI usually results from blunt trauma and penetrating trauma. The majority causes of blunt TDI are victims of motor vehicle accidents. The incidence rates of TDI is unknown because of it can be overlooked if it is unsuspected with non-specific radiological and clinical findings. The mortality rates associated with blunt and penetrating TDI are affected by the severity of concurrent organ injuries. The diagnoses of TDI are frequently missed in the post-traumatic assessment because of non-specific symptoms or physical findings. When the site of trauma is in the abdomen, there will be high rate of an intra-abdominal organ injury. Furthermore, when the site of trauma is in the chest, there will be the abdominal organ injury in 50%.Surgical operation should be performed as soon as possible for concomitant injuries. Diaphragmatic repair can be performed using laparotomy, thoracotomy, or both approaches. Primary suture of the diaphragm can be performed in the majority of TDI patients. The outcome of post TDI depends on concurrent organ injury. In case of emergency, it is important to take an appropriate diagnosis and treatment for any concomitant injuries. PMID:26197916
Monitoring and preventing diaphragm injury
Heunks, Leo M.A.; Doorduin, Jonne; van der Hoeven, Johannes G.
Purpose of review The present review summarizes developments in the field of respiratory muscle monitoring, in particular in critically ill patients. Recent findings Patients admitted to the ICU may develop severe respiratory muscle dysfunction in a very short time span. Among other factors, disuse and sepsis have been associated with respiratory muscle dysfunction in these patients. Because weakness is associated with adverse outcome, including prolonged mechanical ventilation and mortality, it is surprising that respiratory muscle dysfunction largely develops without being noticed by the clinician. Respiratory muscle monitoring is not standard of care in most ICUs. Improvements in technology have opened windows for monitoring the respiratory muscles in critically ill patients. Diaphragm electromyography and esophageal pressure measurement are feasible techniques for respiratory muscle monitoring, although the effect on outcome remains to be investigated. Summary Respiratory muscle dysfunction develops rapidly in selected critically ill patients and is associated with adverse outcome. Recent technological advances allow real-time monitoring of respiratory muscle activity in these patients. Although this field is in its infancy, from a physiological perspective, it is reasonable to assume that monitoring respiratory muscle activity improves outcome in these patients. PMID:25546533
Airflow limitation is accompanied by diaphragm dysfunction.
Hellebrandová, L; Chlumský, J; Vostatek, P; Novák, D; Rýznarová, Z; Bunc, V
Chronic airflow limitation, caused by chronic obstructive pulmonary disease (COPD) or by asthma, is believed to change the shape and the position of the diaphragm due to an increase in lung volume. We have made a comparison of magnetic resonance imaging (MRI) of diaphragm in supine position with pulmonary functions, respiratory muscle function and exercise tolerance. We have studied the differences between patients with COPD, patients with asthma, and healthy subjects. Most interestingly we found the lung hyperinflation leads to the changes in diaphragmatic excursions during the breathing cycle, seen in the differences between the maximal expiratory diaphragm position (DPex) in patients with COPD and control group (p=0.0016). The magnitude of the diaphragmatic dysfunction was significantly related to the airflow limitation expressed by the ratio of forced expiratory volume in 1 s to slow vital capacity (FEV(1)/SVC), (%, p=0.0007); to the lung hyperinflation expressed as the ratio of the residual volume to total lung capacity (RV/TLC), (%, p=0.0018) and the extent of tidal volume constrain expressed as maximal tidal volume (V(Tmax)), ([l], p=0.0002); and the ratio of tidal volume to slow vital capacity (V(T)/SVC), (p=0.0038) during submaximal exercise. These results suggest that diaphragmatic movement fails to contribute sufficiently to the change in lung volume in emphysema. Tests of respiratory muscle function were related to the position of the diaphragm in deep expiration, e.g. neuromuscular coupling (P(0.1)/V(T)) (p=0.0232). The results have shown that the lung volumes determine the position of the diaphragm and function of the respiratory muscles. Chronic airflow limitation seems to change the position of the diaphragm, which thereafter influences inspiratory muscle function and exercise tolerance. There is an apparent relationship between the position of the diaphragm and the pulmonary functions and exercise tolerance. PMID:27070746
Manual evaluation of the diaphragm muscle.
Bordoni, Bruno; Marelli, F; Morabito, B; Sacconi, B
The respiratory diaphragm is the most important muscle for breathing. It contributes to various processes such as expectoration, vomiting, swallowing, urination, and defecation. It facilitates the venous and lymphatic return and helps viscera located above and below the diaphragm to work properly. Its activity is fundamental in the maintenance of posture and body position changes. It can affect the pain perception and emotional state. Many authors reported on diaphragmatic training by using special instruments, whereas only a few studies focused on manual therapy approaches. To the knowledge of the authors, the existing scientific literature does not exhaustively examines the manual evaluation of the diaphragm in its different portions. A complete evaluation of the diaphragm is mandatory for several professional subjects, such as physiotherapists, osteopaths, and chiropractors not only to elaborate a treatment strategy but also to obtain information on the validity of the training performed on the patient. This article aims to describe a strategy of manual evaluation of the diaphragm, with particular attention to anatomical fundamentals, in order to stimulate further research on this less explored field. PMID:27574419
Manual evaluation of the diaphragm muscle
Bordoni, Bruno; Marelli, F; Morabito, B; Sacconi, B
The respiratory diaphragm is the most important muscle for breathing. It contributes to various processes such as expectoration, vomiting, swallowing, urination, and defecation. It facilitates the venous and lymphatic return and helps viscera located above and below the diaphragm to work properly. Its activity is fundamental in the maintenance of posture and body position changes. It can affect the pain perception and emotional state. Many authors reported on diaphragmatic training by using special instruments, whereas only a few studies focused on manual therapy approaches. To the knowledge of the authors, the existing scientific literature does not exhaustively examines the manual evaluation of the diaphragm in its different portions. A complete evaluation of the diaphragm is mandatory for several professional subjects, such as physiotherapists, osteopaths, and chiropractors not only to elaborate a treatment strategy but also to obtain information on the validity of the training performed on the patient. This article aims to describe a strategy of manual evaluation of the diaphragm, with particular attention to anatomical fundamentals, in order to stimulate further research on this less explored field. PMID:27574419
Parallel valveless micropump with two flexible diaphragms
NASA Astrophysics Data System (ADS)
Su, Yufeng; Chen, Wenyuan; Cui, Feng; Zhang, Weiping
This paper presents a parallel dynamic passive valveless micropump, which consists of three layers-valve, diaphragm and electromagnetic coil. The valve is wetly etched in a silicon wafer, the diaphragm is a PDMS (polydimethyl siloxane) film spun on a silicon wafer with embedded permanent magnet posts, and the coil is electroplated on a silicon substrate. Under the actuation of the magnetic field of the coil, the flexible diaphragm can be displaced upwards and downwards. After analyzing magnetic and mechanical characteristic of the flexible membrane and direction-dependence of the diffuser, this paper designed a micropump. And the relative length (L/d) of the micropump"s diffuser is 4.An 7×7 array of permanent magnetic posts is embedded in the PDMS film. Two diaphragms work in an anti-step mode, which can relieve the liquid shock and increase the discharge of the micropump. ANSYS« and Matlab« are adopted to analyze the actuation effect of the coil and the flow characteristic of the micropump. Results show that when actuated under a 0.3A, 100Hz current ,the displacement of the diaphragm is more than 30μm, and the discharge of the micropump is about 6μL/s.
Diaphragm based high sensitive FBG pressure sensor
NASA Astrophysics Data System (ADS)
Vengal Rao, P.; Srimannarayana, K.; Sai Shankar, M.; Kishore, P.
A high sensitive pressure sensor based on Fiber Bragg grating (FBG) integrated with a thin metal diaphragm was designed and demonstrated. To enhance the pressure sensitivity FBG is firmly glued across the diameter of the diaphragm. Under pressure, the diaphragm deforms and produces an induced strain along the length of the fiber causes shift in Bragg wavelength of the FBG. Pressure measurement is made by measuring the Bragg wavelength shift against change in pressure. The sensor was tested up to the maximum pressure of 140 psi and the corresponding pressure sensitivity was found to be 0.0204 nm/psi, which is approximately 970 times higher than that can be achieved with a bare FBG. The experimental results show good agreement with the theoretical results and possess good linearity and repeatability. This sensor can be used for the measurement of medium pressure, liquid level and depth of underwater.
Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms
NASA Technical Reports Server (NTRS)
Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.
Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.
Cyclotene diaphragm for MEMS based IR detectors
NASA Astrophysics Data System (ADS)
Guo, Shuwen
A novel structure employing Dow Chemical (Midland, MI) benzocyclobutene (BCB) Cyclotene as a diaphragm material is presented in this report. The main advantages of this BCB diaphragm are its low thermal conductivity, robustness, chemical inertness, low curing temperature and high structure yield. Moreover, a BCB film can be either photo-defined or plasma etched and is a suitable micromachining material for post IC processing. Micromachined IR thermopile single detectors and lineal detector arrays (1×16), using BiSeTeSb/BiSbTe sensing elements on BCB diaphragms, have been constructed and tested. Up to 100% structure yield has been obtained. The process used to realize this detector structure is compatible with the eventual inclusion of on-chip circuitry for signal amplification and conditioning.
La chirurgie du diaphragme sous aortique
Moutakiallah, Younes; Maaroufi, Ilham; Aithoussa, Mahdi; Bamous, Mehdi; Abdou, Abdessamad; Atmani, Noureddine; Hatim, Abdedaïm; Amahzoune, Brahim; Bekkali, Youssef El; Boulahya, Abdelatif
Le diaphragme sous aortique se caractérise par une certaine latence clinique et une faible morbi-mortalité. La chirurgie reste le traitement de choix malgré un réel risque de récurrence à long terme. Nous rapportons 18 patients opérés entre Avril 1994 et Mars 2011 pour diaphragme sous aortique d'âge moyen de 18,1±9,7 ans avec 11 patients de sexe masculin. Le diaphragme était de nature fibreuse chez 13 patients et fibro-musculaire chez 5 patients. Tous les patients ont été opérés par résection de diaphragme associée à une myectomie, une plastie aortique, une fermeture de communication interventriculaire et une ligature de canal artériel perméable respectivement chez 3, 3, 2 et 2 patients. La Mortalité opératoire était nulle et sans aucun cas de trouble de conduction postopératoire. Le suivi a duré en moyenne 44,3±36,8 mois sans aucun décès tardif. Deux patients ont présenté une récidive de diaphragme qui a nécessité une réopération avec bonne évolution. La tendance actuelle dans la chirurgie du diaphragme se fait vers des interventions précoces et des résections plus extensives. Cependant, le risque de récidive impose une surveillance échographique systématique et rapprochée. PMID:27516830
Laparoscopic Robot-Assisted Diaphragm Plication.
Zwischenberger, Brittany A; Kister, Nathaniel; Zwischenberger, Joseph B; Martin, Jeremiah T
Minimally invasive approaches to diaphragm plication for eventration include thoracoscopic and laparoscopic techniques. The elevated hemidiaphragm and ribs limit thoracoscopic techniques. We report our modification of the laparoscopic approach using robotic assistance with the da Vinci Surgical System, (Intuitive Surgical Inc, Sunnyvale, CA) to avoid single-lung ventilation, facilitate exposure, and allow more precise placement of plication sutures to achieve an even tension and maximum plication. Critical steps include creation of a small defect in the diaphragm to equalize pressures between cavities and placement of multiple, pledgeted interrupted horizontal mattresses. PMID:26694286
Diaphragm eliminates leakage in cryogenic fluid duct coupling
NASA Technical Reports Server (NTRS)
Duct coupling with nickel steel diaphragm of low thermal expansivity is leakproof when used with cryogenic fluids. The diaphragm, located between the two flanges of the coupling, reduces axial shrinkage at the coupling flanges to a minimum.
14 CFR 25.1192 - Engine accessory section diaphragm.
Code of Federal Regulations, 2011 CFR
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm...
14 CFR 125.149 - Engine accessory section diaphragm.
Code of Federal Regulations, 2011 CFR
... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate...
14 CFR 125.149 - Engine accessory section diaphragm.
Code of Federal Regulations, 2012 CFR
... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate...
14 CFR 125.149 - Engine accessory section diaphragm.
Code of Federal Regulations, 2013 CFR
... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate...
14 CFR 25.1192 - Engine accessory section diaphragm.
Code of Federal Regulations, 2014 CFR
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm...
TFE coating extends life of flexible metal compressor diaphragm
NASA Technical Reports Server (NTRS)
Gorland, S.
Tetrafluoroethylene /TFE/ aerosol sprayed onto entire surface of diaphragm acts as film lubricant and permits diaphragm to slide between upper and lower plates in a reciprocating compressor. Flexing occurs over an area rather than about a single line of action and operating life of diaphragm is more than quadrupled.
14 CFR 25.1192 - Engine accessory section diaphragm.
Code of Federal Regulations, 2012 CFR
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm...
14 CFR 25.1192 - Engine accessory section diaphragm.
Code of Federal Regulations, 2010 CFR
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm...
14 CFR 125.149 - Engine accessory section diaphragm.
Code of Federal Regulations, 2010 CFR
... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate...
[A case of rupture of the diaphragm caused by the plication for diaphragm eventration].
Muro, K; Yanagihara, K; Mizuno, H; Kurata, M
A 71-year-old woman, in whom the herniation of right-sided diaphragm was diagnosed, was admitted to our hospital on ambulance car complaining of increasing right-sided chest pain and worsening of dyspnea. She was given emergency laparotomy. The transverse colon and omentum pushed the liver backward. The tight adhesion between transverse colon and diaphragm was released by using thoracotomy additionally. In pleural cavity, there was prolapsing transverse colon which was not covered with peritonium and was caused by the rupture of right-sided diaphragm. The necrotic transverse colon was resected about 30 cm length. We considered that the rupture was caused not by external injury but by inflammation after plication for diaphragm eventration three years and ten months before. PMID:9654933
Diaphragm remodeling and compensatory respiratory mechanics in a canine model of Duchenne muscular dystrophy
Mead, A. F.; Petrov, M.; Malik, A. S.; Mitchell, M. A.; Childers, M. K.; Bogan, J. R.; Seidner, G.; Kornegay, J. N.
Ventilatory insufficiency remains the leading cause of death and late stage morbidity in Duchenne muscular dystrophy (DMD). To address critical gaps in our knowledge of the pathobiology of respiratory functional decline, we used an integrative approach to study respiratory mechanics in a translational model of DMD. In studies of individual dogs with the Golden Retriever muscular dystrophy (GRMD) mutation, we found evidence of rapidly progressive loss of ventilatory capacity in association with dramatic morphometric remodeling of the diaphragm. Within the first year of life, the mechanics of breathing at rest, and especially during pharmacological stimulation of respiratory control pathways in the carotid bodies, shift such that the primary role of the diaphragm becomes the passive elastic storage of energy transferred from abdominal wall muscles, thereby permitting the expiratory musculature to share in the generation of inspiratory pressure and flow. In the diaphragm, this physiological shift is associated with the loss of sarcomeres in series (∼60%) and an increase in muscle stiffness (∼900%) compared with those of the nondystrophic diaphragm, as studied during perfusion ex vivo. In addition to providing much needed endpoint measures for assessing the efficacy of therapeutics, we expect these findings to be a starting point for a more precise understanding of respiratory failure in DMD. PMID:24408990
The use of the diaphragm instead of condoms in a phase III diaphragm trial.
van der Straten, Ariane; Cheng, Helen; Moore, Jie; Kacanek, Deborah; Blanchard, Kelly; De Bruyn, Guy; Ramjee, Gita; Chipato, Tsungai; Montgomery, Elizabeth T; Padian, Nancy
The MIRA trial assessed whether providing diaphragm, lubricant gel, and condoms (intervention) compared with condoms alone (control) could reduce HIV incidence among 5,039 Southern African women. Compared with the control group, the cumulative proportion of last sex acts protected by any method was higher in the intervention group (OR = 1.33; 95% CI 1.18, 1.49); however, only 36.3% of last sex acts were protected by both a male condom and a diaphragm, whereas 36.6% were protected by a diaphragm only. Product substitution (ever deciding to use a diaphragm instead of a condom in the previous 3 months) was reported at every visit by 22.4%, at some visits by 60.7%, and at none of the visits by 16.8% of these women. Women at greater risk for infection through their own or their partner's behavior or who believed the diaphragm protected against HIV were more likely to report product substitution at every visit. PMID:19085099
Sesitashvili, T; Tomadze, G; Gvantseladze, G; Rekhviashvili, A
Diaphragmatic agenesis is the most extreme and rare form of congenital diaphragmatic maldevelopment and therefore diagnosis of it are only few in literature, especially in children. It may be unilateral or bilateral. Frequently, diaphragmatic agenesis is accompanied with diaphragmatic hernia, when through a congenital defect of the diaphragm liver, intestine and other viscera herniate into the chest. Diagnostics typically are made early in infancy and is generally associated with other genetic anomalies, especially aneuploidy syndromes. It is associated with a high mortality, if not treated in infancy. However, according to published literature only a few patients have survived till adulthood. In this report, we describe the case of a 63 years old male patient who admitted in a hospital with small bowel intussusception because of strangulated intestinal obstruction and peritonitis. While surgical operation and revision of abdominal cavity, partial right-sided agenesis of the diaphragm was revealed. Two operations were performed on a patient; one because of strangulated intestinal obstruction and accompanied peritonitis and the second, because of stitch insufficiency after 5 days from the first surgical operation. Taking into account the heavy overall status of the patient, diaphragm plastic was not performed and its performance postponed for future. PMID:27119827
First disposable diaphragm will gradually release spermicide.
The Southern Research Institute in Birmingham, Alabama will begin phase 1 trials of a new disposable disphragm with a controlled release spermicide as soon as they obtain Federal Drug Administration approval. The device is made of synthetic elastomer which contains a premixed nonoxynol-9 spermicide. Vaginal fluid causes the spermicide to build up and additional spermicide is released when the initial supply is depleted. The device is effective for up to 24 hours and the controlled release of spermicide makes it unnecessary to add spermicide if intercourse is repeated. Addditional advantages are that it is disposable, requires no inspection or cleaninng and is not messy. During the 1st phase of clinical study, 10-12 women will use the diaphragm, and they will report on its comfort, how well it stays in place, and whether it causes any local irritation. In the 2nd phase, 20 women will undergo postcoital testing in order to determine if the device is releasing sufficient levels of spermicide to immobilize sperm. Initally the diaphragms will be fitted by a phsician who will then write a prescription for the device. Eventually the diaphragm may be available in a one size fits all model which will be sold over the counter. The price of the device is expected to be about $1.00, and it will be on the market in about 3 years. PMID:12313084
Diaphragm Pump With Resonant Piezoelectric Drive
NASA Technical Reports Server (NTRS)
Izenson, Michael G.; Kline-Schoder, Robert J.; Shimko, Martin A.
A diaphragm pump driven by a piezoelectric actuator is undergoing development. This pump is intended to be a prototype of lightweight, highly reliable pumps for circulating cooling liquids in protective garments and high-power electronic circuits, and perhaps for some medical applications. The pump would be highly reliable because it would contain no sliding seals or bearings that could wear, the only parts subject to wear would be two check valves, and the diaphragm and other flexing parts could be designed, by use of proven methods, for extremely long life. Because the pump would be capable of a large volumetric flow rate and would have only a small dead volume, its operation would not be disrupted by ingestion of gas, and it could be started reliably under all conditions. The prior art includes a number piezoelectrically actuated diaphragm pumps. Because of the smallness of the motions of piezoelectric actuators (typical maximum strains only about 0.001), the volumetric flow rates of those pumps are much too small for typical cooling applications. In the pump now undergoing development, mechanical resonance would be utilized to amplify the motion generated by the piezoelectric actuator and thereby multiply the volumetric flow rate. The prime mover in this pump would be a stack of piezoelectric ceramic actuators, one end of which would be connected to a spring that would be part of a spring-and-mass resonator structure. The mass part of the resonator structure would include the pump diaphragm (see Figure 1). Contraction of the spring would draw the diaphragm to the left, causing the volume of the fluid chamber to increase and thereby causing fluid to flow into the chamber. Subsequent expansion of the spring would push the diaphragm to the right, causing the volume of the fluid chamber to decrease, and thereby expelling fluid from the chamber. The fluid would enter and leave the chamber through check valves. The piezoelectric stack would be driven electrically to
Inflatable containment diaphragm for sealing and removing stacks
Meskanick, Gerald R.; Rosso, David T.
A diaphragm with an inflatable torus-shaped perimeter is used to seal at least one end of a stack so that debris that might be hazardous will not be released during removal of the stack. A diaphragm is inserted and inflated in the lower portion of a stack just above where the stack is to be cut such that the perimeter of the diaphragm expands and forms a seal against the interior surface of the stack.
Inflatable containment diaphragm for sealing and removing stacks
Meskanick, G.R.; Rosso, D.T.
A diaphragm with an inflatable torus-shaped perimeter is used to seal at least one end of a stack so that debris that might be hazardous will not be released during removal of the stack. A diaphragm is inserted and inflated in the lower portion of a stack just above where the stack is to be cut such that the perimeter of the diaphragm expands and forms a seal against the interior surface of the stack.
Contraction of the human diaphragm during rapid postural adjustments.
Hodges, P W; Butler, J E; McKenzie, D K; Gandevia, S C
1. The response of the diaphragm to the postural perturbation produced by rapid flexion of the shoulder to a visual stimulus was evaluated in standing subjects. Gastric, oesophageal and transdiaphragmatic pressures were measured together with intramuscular and oesophageal recordings of electromyographic activity (EMG) in the diaphragm. To assess the mechanics of contraction of the diaphragm, dynamic changes in the length of the diaphragm were measured with ultrasonography. 2. With rapid flexion of the shoulder in response to a visual stimulus, EMG activity in the costal and crural diaphragm occurred about 20 ms prior to the onset of deltoid EMG. This anticipatory contraction occurred irrespective of the phase of respiration in which arm movement began. The onset of diaphragm EMG coincided with that of transversus abdominis. 3. Gastric and transdiaphragmatic pressures increased in association with the rapid arm flexion by 13.8 +/- 1.9 (mean +/- S.E.M.) and 13.5 +/- 1.8 cmH2O, respectively. The increases occurred 49 +/- 4 ms after the onset of diaphragm EMG, but preceded the onset of movement of the limb by 63 +/- 7 ms. 4. Ultrasonographic measurements revealed that the costal diaphragm shortened and then lengthened progressively during the increase in transdiaphragmatic pressure. 5. This study provides definitive evidence that the human diaphragm is involved in the control of postural stability during sudden voluntary movement of the limbs. Images Figure 1 PMID:9423192
Chronic Assessment of Diaphragm Muscle EMG Activity across Motor Behaviors
Mantilla, Carlos B.; Seven, Yasin B.; Hurtado-Palomino, Juan N.; Zhan, Wen-Zhi; Sieck, Gary C.
The diaphragm muscle is main inspiratory muscle in mammals. Quantitative analyses documenting the reliability of chronic diaphragm EMG recordings are lacking. Assessment of ventilatory and non-ventilatory motor behaviors may facilitate evaluating diaphragm EMG activity over time. We hypothesized that normalization of diaphragm EMG amplitude across behaviors provides stable and reliable parameters for longitudinal assessments of diaphragm activity. We found that diaphragm EMG activity shows substantial intra-animal variability over 6 weeks, with coefficient of variation (CV) for different behaviors ~29–42%. Normalization of diaphragm EMG activity to near maximal behaviors (e.g., deep breathing) reduced intra-animal variability over time (CV ~22–29%). Plethysmographic measurements of eupneic ventilation were also stable over 6 weeks (CV ~13% for minute ventilation). Thus, stable and reliable measurements of diaphragm EMG activity can be obtained longitudinally using chronically implanted electrodes by examining multiple motor behaviors. By quantitatively determining the reliability of longitudinal diaphragm EMG analyses, we provide an important tool for evaluating the progression of diseases or injuries that impair ventilation. PMID:21414423
Clinical significance of severe isolated diaphragm weakness.
Laroche, C M; Carroll, N; Moxham, J; Green, M
We studied six patients with isolated bilateral paralysis or severe weakness of the diaphragm, present for 2 to 60 months (mean = 25), to document the clinical and respiratory sequelae of the condition. Severe diaphragm dysfunction was confirmed by the demonstration of the very low maximal transdiaphragmatic pressure (Pdi) generated by either a sniff (13 +/- 6 cm H2O, normal 148 +/- 24) or a static inspiration (11 +/- 8, normal 108 +/- 30) and during bilateral phrenic nerve stimulation (0.8 +/- 2.0, normal 22 +/- 4). Resting arterial blood gases were normal (SaO2 = 95 to 97%) and no oxygen desaturation occurred during maximal exercise on a treadmill. Maximum voluntary ventilation was low and related to PImax (r = 0.89). Overnight sleep monitoring showed that time spent in rapid eye movement sleep was normal (mean 55 +/- 36 min, range 26 to 117 min). Mean maximum increment in transcutaneous CO2 was within normal limits (6 +/- 2 mm Hg, range 3 to 9 mm Hg). Three patients had occasional brief episodes of oxygen desaturation (mean maximal decrease 13 +/- 10%, range 2 to 27%); however, only two of these spent a measurable proportion of total sleep time (TST) with an SaO2 of less than 80% (1% and 3% TST, respectively). No patient has developed any symptoms of nocturnal hypoventilation or chronic respiratory failure during periods of observation of up to five yr. We conclude that bilateral paralysis or very severe weakness of the diaphragm does not of itself lead to respiratory failure unless weakness of other respiratory muscles is present. PMID:3202460
Production of porous diaphragm for electrolytic cell
Cairns, J.F.
A process for the production of a porous diaphragm suitable for use in an electrolytic cell, particularly a chlor-alkali cell, characterized in that the process comprises irradiating a porous shaped article of an organic polymeric material, for example, a sheet of a fluoropolymer, with high energy radiation, the irradiation being effected in the presence of, or the irradiated shaped article being subsequently contacted with, a reactant selected from ammonia, carbon monoxide and phosgene, and the sheet preferably being subsequently contacted with an aqueous alkaline solution.
Cervical spinal cord injury exacerbates ventilator-induced diaphragm dysfunction.
Smuder, Ashley J; Gonzalez-Rothi, Elisa J; Kwon, Oh Sung; Morton, Aaron B; Sollanek, Kurt J; Powers, Scott K; Fuller, David D
Cervical spinal cord injury (SCI) can dramatically impair diaphragm muscle function and often necessitates mechanical ventilation (MV) to maintain adequate pulmonary gas exchange. MV is a life-saving intervention. However, prolonged MV results in atrophy and impaired function of the diaphragm. Since cervical SCI can also trigger diaphragm atrophy, it may create preconditions that exacerbate ventilator-induced diaphragm dysfunction (VIDD). Currently, no drug therapy or clinical standard of care exists to prevent or minimize diaphragm dysfunction following SCI. Therefore, we first tested the hypothesis that initiating MV acutely after cervical SCI will exacerbate VIDD and enhance proteolytic activation in the diaphragm to a greater extent than either condition alone. Rats underwent controlled MV for 12 h following acute (∼24 h) cervical spinal hemisection injury at C2 (SCI). Diaphragm tissue was then harvested for comprehensive functional and molecular analyses. Second, we determined if antioxidant therapy could mitigate MV-induced diaphragm dysfunction after cervical SCI. In these experiments, SCI rats received antioxidant (Trolox, a vitamin E analog) or saline treatment prior to initiating MV. Our results demonstrate that compared with either condition alone, the combination of SCI and MV resulted in increased diaphragm atrophy, contractile dysfunction, and expression of atrophy-related genes, including MuRF1. Importantly, administration of the antioxidant Trolox attenuated proteolytic activation, fiber atrophy, and contractile dysfunction in the diaphragms of SCI + MV animals. These findings provide evidence that cervical SCI greatly exacerbates VIDD, but antioxidant therapy with Trolox can preserve diaphragm contractile function following acute SCI. PMID:26472866
Experimental investigation of solar powered diaphragm and helical pumps
Technology Transfer Automated Retrieval System (TEKTRAN)
For several years, many types of solar powered water pumping systems were evaluated, and in this paper, diaphragm and helical solar photovoltaic (PV) powered water pumping systems are discussed. Data were collected on diaphragm and helical pumps which were powered by different solar PV arrays at mul...
14 CFR 23.1192 - Engine accessory compartment diaphragm.
Code of Federal Regulations, 2011 CFR
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...
14 CFR 23.1192 - Engine accessory compartment diaphragm.
Code of Federal Regulations, 2014 CFR
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...
14 CFR 23.1192 - Engine accessory compartment diaphragm.
Code of Federal Regulations, 2012 CFR
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...
14 CFR 23.1192 - Engine accessory compartment diaphragm.
Code of Federal Regulations, 2010 CFR
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...
Diaphragm degeneration and cardiac structure in mdx mouse: potential clinical implications for Duchenne muscular dystrophy.
Barbin, Isabel Cristina Chagas; Pereira, Juliano Alves; Bersan Rovere, Matheus; de Oliveira Moreira, Drielen; Marques, Maria Julia; Santo Neto, Humberto
We examined the effects of exercise on diaphragm degeneration and cardiomyopathy in dystrophin-deficient mdx mice. Mdx mice (11 months of age) were exercised (swimming) for 2 months to worsen diaphragm degeneration. Control mdx mice were kept sedentary. Morphological evaluation demonstrated increased fibrosis in the diaphragm of exercised mdx mice (33.3 ± 6.0% area of fibrosis) compared with control mdx mice (20.9 ± 1.7% area of fibrosis). Increased (26%) activity of MMP-2, a marker of fibrosis, was detected in the diaphragms from exercised mdx mice. Morphological evaluation of the heart demonstrated a 45% increase in fibrosis in the right ventricle (8.3 ± 0.6% in sedentary vs. 12.0 ± 0.6% of fibrosis in exercised) and in the left ventricle (35% increase) in the exercised mdx mice. The density of inflammatory cells-degenerating cardiomyocytes increased 95% in the right ventricle (2.3 ± 0.6 in sedentary vs. 4.5 ± 0.8 in exercised) and 71% in the left ventricle (1.4 ± 0.6 sedentary vs. 2.4 ± 0.5 exercised). The levels of both active MMP-2 and the pro-fibrotic factor transforming growth factor beta were elevated in the hearts of exercised compared with sedentary mdx mice. The wall thickness to lumen diameter ratio of the pulmonary trunk was significantly increased in the exercised mdx mice (0.11 ± 0.04 in sedentary vs. 0.28 ± 0.12 in exercised), as was the thickness of the right ventricle wall, which suggests the occurrence of pulmonary hypertension in those animals. It is suggested that diaphragm degeneration is a main contributor to right ventricle dystrophic pathology. These findings may be relevant for future interventional studies for Duchenne muscular dystrophy-associated cardiomyopathy. PMID:26822140
Association between diaphragm use and urinary tract infection.
Fihn, S D; Latham, R H; Roberts, P; Running, K; Stamm, W E
We conducted independent case-control and retrospective cohort investigations to assess the relationship between diaphragm use and urinary tract infection (UTI). In the former, we compared diaphragm use and vaginal flora among 114 women with acute UTI and 85 women with acute urinary tract symptoms and no UTI. In the latter study, we ascertained the incidence of UTI in 192 diaphragm users and 182 women taking oral contraceptives during a mean follow-up of 9.4 months. Both studies demonstrated a significantly increased risk of UTI in diaphragm users: relative odds were 2.0 in the case-control study and the relative risk was 2.5 in the retrospective cohort study. Vaginal colonization with Escherichia coli was significantly greater in diaphragm users. The incidence of UTI in the cohort study was 26.6 per 1,000 patient-months for diaphragm users and 8.9 per 1,000 patient-months for women taking oral contraceptives. The increased risk of UTI in diaphragm users could not be attributed to differences in age, parity, sexual activity, or previous UTI. PMID:3999367
Pressure-volume characteristics of dielectric elastomer diaphragms
NASA Astrophysics Data System (ADS)
Tews, Alyson M.; Pope, Kimberly L.; Snyder, Alan J.
With the ultimate goal of constructing diaphragm-type pumps, we have measured pressure-volume characteristics of single-layer dielectric elastomers diaphragms. Circular dielectric elastomer diaphragms were prepared by biaxial stretching of 3M VHB 4905 polyacrylate, or spin casting and modest or no biaxial stretching of silicone rubber films, followed by mounting to a sealed chamber having a 3.8 cm diameter opening. Pressure-volume characteristics were measured at voltages that provided field strengths up to 80 MV/m in un-deformed VHB films and 50-75 MV/m in silicone films. The most highly pre-strained VHB diaphragms were found to have linear pressure-volume characteristics whose slopes (diaphragm compliance) depended sensitively upon applied field at higher field strengths. Compliance of unstretched silicone diaphragms was nearly independent of field strength at the fields tested, but pressure-volume characteristics shifted markedly. For both kinds of dielectric elastomers, pressure-volume work loops of significant size can be obtained for certain operating pressures. Each type of diaphragm may have advantages in certain applications.
a Low Cost Pressure Wave Generator Using Diaphragms
NASA Astrophysics Data System (ADS)
Caughley, A. J.; Haywood, D. J.; Wang, C.
The high cost of Pressure Wave Generators (PWGs) is a major barrier to the more widespread use of high-efficiency pulse tube and Stirling cryocoolers. This paper describes the development and testing of a low-cost industrial-style PWG which employs metal diaphragms. The use of diaphragms removes the need for rubbing or clearance seals, and eliminates contamination problems by hermetically separating the gas circuit and the lubricated driving mechanism. A conventional low-cost electric motor is used for power input, via a novel high-efficiency kinematic linkage. A first prototype of the diaphragm PWG produced 3.2 kW of PV power with a measured electro-acoustic efficiency of 72%. Accelerated testing predicts a diaphragm life time in excess of 40,000 hours. An additional advantage of the use of diaphragms is the ability to directly cool the gas in the compression space. This eliminates or significantly reduces the requirement for an after cooler, and further decreases the cost of the whole cryocooler system. A pulse tube cryocooler has been successfully run at Industrial Research Ltd to 59K with the diaphragm PWG and no aftercooler. Another pulse tube cryocooler with the diaphragm PWG is undergoing development at Cryomech, the results of which will be given in another presentation.
Accessory diaphragm associated with non-immune hydrops fetalis
Priyadarshi, Archana; Sugo, Ella; Challis, Daniel; Bolisetty, Srinivas
An accessory diaphragm, also known as diaphragmatic duplication, is a congenital anomaly in which there is a fibromuscular membrane on top of the normally formed diaphragm dividing the hemithorax into two compartments trapping part of the pulmonary parenchyma. It is a very rare anomaly with less than 40 cases reported in the literature, of which only five were diagnosed in the newborn period, with no reports on any clinical clues for the antenatal diagnosis of this condition. We describe a case of congenital accessory diaphragm presenting in the antenatal period as hydrops fetalis. We also describe the radiological features of this rare anomaly on the antenatal fetal ultrasound. PMID:25100808
Analysis of diaphragm forming of powder impregnated thermoplastic composites
NASA Astrophysics Data System (ADS)
Cutolo, D.; Canonico, P.; Marchetti, M.; Porcari, A. M.
A new technology for making thermoplastic prepreg uses a fiber impregnated thermoplastic (FIT) process. Fabric woven from FIT tow prepreg shows a great deal of drapability. A study has been conducted on diaphragm forming technology, using FIT woven fabric made of glass fibers and polyimide. A double curvature mold was used to form hemispherical parts by applying differential pressures across double polyimide diaphragms. Effects of forming rate, lay-up, and cross-section thickness have been investigated. Deformation of diaphragms has been also investigated.
Vaginal diaphragm rings in the treatment of stress urinary incontinence.
Realini, J P; Walters, M D
To assess the effectiveness of wearing vaginal diaphragm rings in the treatment of stress urinary incontinence, 10 women with genuine stress incontinence were studied. Patients underwent urodynamic evaluation and perineal pad testing before and after fitted diaphragm rings were in place. Patients kept symptom diaries for 1 week without the ring and then for 1 week with the ring. They also gave an overall subjective evaluation of their experience. Urodynamic findings were essentially unchanged by wearing diaphragm rings. Trends toward improvement were observed in the results of pad tests and symptom diaries. Four of the 10 women experienced clinically significant improvement in amount of urine lost during pad tests, number of leaks per week, and overall assessment of response. Vaginal diaphragm rings may be an effective treatment for some women with stress urinary incontinence. PMID:2333769
Seismic response of a large-span roof diaphragm
Celebi, Mehmet; Bongiovanni, Giovanni; Safak, Erdal; Brady, A. Gerald
Records obtained from the West Valley College Gymnasium in Saratoga, California during the 1984 Morgan Hill earthquake are used to study the dynamic behavior of the overall gymnasium as well as its flexible disaphragm. The ground-level motions recorded in the two orthogonal axes of the structure differ considerably in peak acceleration and amplify by approximately 1.5 times at the roof edges and by 4-5 times at the center of the diaphragm. The diaphragm responds with a frequency of approximately 4 Hz in both orthogonal axes. A simple finite-element model is used to match the fundamental frequency of the diaphragm with that from the records. Using this model and the ground-level motions as input, the diaphragm center displacements are calculated by varying the structural damping. Best comparisons are obtained for 5% damping. These results are discussed in terms of the code provisions.
Investigation of the diaphragm-type pressure cell
NASA Technical Reports Server (NTRS)
Theodorsen, Theodore
This report relates to various improvements in the process of manufacture of the NACA standard pressure cell. Like most pressure recording devices employing thin diaphragms, they would in general show considerable change in calibration with temperature and also some change of calibration with time or aging effect. The required diaphragm thickness and the desirable rate of mechanical magnification have been determined on the basis of several hundred tests.
Formation of sodium chlorate in diaphragmed chlorine electrolyzers
Gorbachev, A.K.; Andryushchenko, F.K.; Maksimchuk, E.F.; Potapov, V.N.
This paper examines the formation of sodium chlorate under conditions of diaphragmed electrolysis with ruthenium-titanium oxide anodes. The authors establish that the sodium chlorate is formed chemically in such an electrolyzer. The data indicate that effective methods of reducing the amounts of sodium chlorate in diaphragm chlorine electrolyzers are to supply an acidified brine and to ensure catalytic decomposition of hypochlorous acid and sodium chlorate directly in the electrolyzer.
Fluid Sloshing Characteristics in Spacecraft Propellant Tanks with Diaphragms
NASA Technical Reports Server (NTRS)
Green, Steve; Burkey, Russell; Viana, Flavia; Sudermann, James
All spacecraft are launched from the Earth as payloads on a launch vehicle. During portions of the launch profile, the spacecraft could be subjected to nearly purely translational oscillatory lateral motions as the launch vehicle control system guides the rocket along its flight path. All partially-filled liquids tanks, even those with diaphragms, exhibit sloshing behavior under these conditions and some tanks can place large loads on their support structures if the sloshing is in resonance with the control system oscillation frequency. The objectives of this project were to conduct experiments using a full-scale model of a flight tank to 1) determine whether launch vehicle vibrations can cause the diaphragm to achieve a repeatable configuration, regardless of initial condition, and 2) identify the slosh characteristics of the propellant tank under flight-like lateral motions for different diaphragm shapes and vibration levels. The test results show that 1) the diaphragm shape is not affected by launch vibrations, and 2) the resonance-like behavior of the fluid and diaphragm is strongly affected by the nonlinear stiffness and damping provided by the diaphragm.
Force potentiation in respiratory muscles: comparison of diaphragm and sternohyoid.
Van Lunteren, E; Vafaie, H
Coordinated contraction of thoracic and pharyngeal upper airway respiratory muscles optimizes ventilation, whereas pharyngeal muscle dysfunction may lead to obstructive apneas during sleep. We hypothesized that the force potentiation exhibited by the pharyngeal respiratory muscle, the sternohyoid, in keeping with its faster contractile kinetics, would be greater than that of the thoracic respiratory muscle, the diaphragm. Rat muscles were studied in vitro at 37 degrees C with three force-potentiating protocols: posttetanic twitch potentiation, staircase phenomenon (twitch potentiation), and a classic fatigue paradigm. The sternohyoid had a faster isometric contraction time, a more rightward located force-frequency relationship, and both a more rapid onset and a greater degree of fatigue than the diaphragm. During the early portion of the fatigue protocols, the increase in force was significantly greater for the sternohyoid muscle than the diaphragm (e.g., 33 vs. 3% increase at 20 Hz, P < 0.005). During repetitive twitches at 2, 3, and 5 Hz (staircase test), sternohyoid muscle force increased more than diaphragm force at the higher stimulus frequencies (e.g., by 38 vs. 23% at 5 Hz, P < 0.01). After brief tetanic stimuli, sternohyoid twitch force increased more than diaphragm twitch force (e.g., 73 vs. 14% increase after 125 Hz tetanus, P < 0.005). These data indicate that force potentiation is exhibited by both diaphragm and sternohyoid respiratory muscles, but to different extents, when activated repetitively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8322961
Effects of mechanical ventilation on diaphragm function and biology.
Gayan-Ramirez, G; Decramer, M
The pathophysiological mechanisms of weaning from mechanical ventilation are not fully known, but there is accumulating evidence that mechanical ventilation induces inspiratory muscle dysfunction. Recently, several animal models have provided potential mechanisms for mechanical ventilation-induced effects on muscle function. In patients, weaning difficulties are associated with inspiratory muscle weakness and reduced endurance capacity. Animal studies demonstrated that diaphragm force was already decreased after 12 h of controlled mechanical ventilation and this worsened with time spent on the ventilator. Diaphragmatic myofibril damage observed after 3-days controlled mechanical ventilation was inversely correlated with maximal diaphragmatic force. Downregulation of the diaphragm insulin-like growth factor-I and MyoD/myogenin messenger ribonucleic acid occurred after 24 h and diaphragmatic oxidative stress and increased protease activity after 18 h. In keeping with these findings, diaphragm fibre atrophy was shown after 12 h and reduced diaphragm mass was reported after 48 h of controlled mechanical ventilation. These animal studies show that early alterations in diaphragm function develop after short-term mechanical ventilation. These alterations may contribute to the difficulties in weaning from mechanical ventilation seen in patients. Strategies to preserve respiratory muscle mass and function during mechanical ventilation should be developed. These may include: adaptation of medication, training of the diaphragm, stabilisation of the catabolic state and pharmacotherapy. PMID:12503720
Development of optical diaphragm deflection sensors
NASA Technical Reports Server (NTRS)
Ghering, W. L.; Varshneya, D.; Jeffers, L. A.; Bailey, R. T.; Berthold, J. W.
The objective of this project was to develop high-temperature pressure sensors using non-metallic components and optical sensing methods. The sensors are to operate over a temperature range from room temperature approx. 20C to 540C, to respond to internal pressure up to 690 kPa, to respond to external pressure up to 690 kPa, and to withstand external overpressure of 2070 kPa. Project tasks include evaluating sensing techniques and sensor systems. These efforts include materials and sensing method selection, sensor design, sensor fabrication, and sensor testing. Sensors are tested as a function of temperature, pressure, overpressure, and vibration. The project results show that high-temperature pressure sensors based on glass components and optical sensing methods are feasible. The microbend optical diaphragm deflection sensor exhibits the required sensitivity and stability for use as a pressure sensor with temperature compensation. for the microbend sensor, the 95% confidence level deviation of input pressure from the pressure calculated from the overall temperature-compensated calibration equation is 3.7% of full scale. The limitations of the sensors evaluated are primarily due to the restricted temperature range of suitable commercially available optical fibers and the problems associated with glass-to-metal pressure sealing over the entire testing temperature range.
Characterisation of human diaphragm at high strain rate loading.
Gaur, Piyush; Chawla, Anoop; Verma, Khyati; Mukherjee, Sudipto; Lalvani, Sanjeev; Malhotra, Rajesh; Mayer, Christian
Motor vehicle crashes (MVC׳s) commonly results in life threating thoracic and abdominal injuries. Finite element models are becoming an important tool in analyzing automotive related injuries to soft tissues. Establishment of accurate material models including tissue tolerance limits is critical for accurate injury evaluation. The diaphragm is the most important skeletal muscle for respiration having a bi-domed structure, separating the thoracic cavity from abdominal cavity. Traumatic rupture of the diaphragm is a potentially serious injury which presents in different forms depending upon the mechanisms of the causative trauma. A major step to gain insight into the mechanism of traumatic rupture of diaphragm is to understand the high rate failure properties of diaphragm tissue. Thus, the main objective of this study was to estimate the mechanical and failure properties of human diaphragm at strain rates associated with blunt thoracic and abdominal trauma. A total of 23 uniaxial tensile tests were performed at various strain rates ranging from 0.001-200s(-1) in order to characterize the mechanical and failure properties on human diaphragm tissue. Each specimen was tested to failure at one of the four strain rates (0.001s(-1), 65s(-1), and 130s(-1), 190s(-1)) to investigate the effects of strain rate dependency. High speed video and markers placed on the grippers were used to measure the gripper to gripper displacement. Engineering stresses reported in the study is calculated from the ratio of force measured and initial cross sectional area whereas engineering strain is calculated from the ratio of the elongation to the undeformed length (gauge length) of the specimen.The results of this study showed that the diaphragm tissues is rate dependent with higher strain rate tests giving higher failure stress and higher failure strains. The failure stress for all tests ranged from 1.17MPa to 4.1MPa and failure strain ranged from 12.15% to 24.62%. PMID:27062242
The maximum life expectancy for a micro-fabricated diaphragm
NASA Astrophysics Data System (ADS)
Cǎlimǎnescu, Ioan; Stan, Liviu-Constantin; Popa, Viorica
Micro-fabricated diaphragms can be used to provide pumping action in microvalve and microfluidic applications. The functionality of the microdiaphragm in a wirelessly actuated micropump plays a major role in low-powered device actuation. In developing micropumps and their components, it is becoming an increasing trend to predict the performance before the prototype is fabricated. Because performance prediction allows for an accurate estimation of yield and lifetime, in addition to developing better understanding of the device while taking into account the details of the device structure and second order effects. Hence avoid potential pitfalls in the device operation in a practical environment. The goal of this research is to determine via FEA the life expectancy for a corrugated circular diaphragm made out of an aluminum alloy. The geometry of the diaphragm is given below being generated within SolidWorks 2010, all the calculations were made using Ansys 13TM . The sound design of a micropump is heavily depending on the lifetime expectancy of the working part of the device which is the diaphragm. This will be subjected on cyclic loading and the fatigue will limit the life of this part. Once the diaphragm is breaking, the micropump is no more able to fulfill its scope. Any micropump manufacturer will then be very concerned on the life expectancy from the fatigue point of view of the diaphragms. The diaphragm circular and corrugated and made of Al alloy, showed a very good behavior from the fatigue point of view, the maximum life expectancy being 1.9 years of continuous functioning with 100 cycles per second. This work showed an simple and forward application of FEA analysis methods in order to estimate the fatigue behavior of corrugated circular microdiaphragms.
Precision pneumatic pressure measurement with diaphragm-based mechatronic devices
NASA Astrophysics Data System (ADS)
Karuppanan, Balasubramanian; Akin, Cellatoglu
A clamped circular metallic diaphragm, with shallow spherical shell deformation, elongates spherically proportional to the pressure acting on it. By making use of the inflation characteristics and mechanical properties of the diaphragm, three types of pneumatic pressure sensor are proposed in this article. In the first type, an optical mirror is engraved on its outer surface in an optimal position falling midway between its vertex and circumference. A laser beam is made to incident on the mirror and it gets deflected to fall over a matrix of photocells; the excitation of a particular cell in the coordinates of the matrix determines the pressure acting on the diaphragm. In the second proposal, a weightless secondary coil of a transformer is fixed around the vertex of the diaphragm which would move around a stationary magnetic core. The excitation of the primary coil wound over the magnetic core causes a voltage to be picked up in the secondary coil which would depend upon the displacement of the vertex because of pressure. The third type of the transducer is a capacitance pickup arrangement wherein the pressure is converted into capacitance and it is sensed and displayed as pressure. Furthermore, as an extension of the work, the motion of the diaphragm is mechanically coupled to a stylus for producing hard copy of the pressure over a strip chart.
Diaphragm Pressure Wave Generator Developments at Industrial Research Ltd
NASA Astrophysics Data System (ADS)
Caughley, A. J.; Emery, N.; Glasson, N. D.
Industrial Research Ltd (IRL) have been developing a unique diaphragm based pressure wave generator technology for pulse tube and Stirling cryocoolers. Our system uses a metal diaphragm to separate the clean cryocooler gas circuit from a conventionally lubricated mechanical driver, thus producing a clean pressure wave with a long life drive that does not require the precision manufacture and associated costs of large linear motors. The first successful diaphragm pressure wave generator produced 3.2 kW of acoustic power at an electro-acoustic efficiency of 72% with a swept volume of 200 ml and a prototype has now accumulated over 2500 hours running. This paper describes recent developments in the technology. To explore scaling, a small diaphragm pressure wave generator with a swept volume of 20 ml has been constructed and has delivered 454 W of acoustic power at an electro-acoustic efficiency of 60%. Improvements have been made to the hydraulic force amplifier mechanism for driving the diaphragms resulting in a cheaper and lighter mechanism than the mechanical linkage originally used. To meet a customer's specific requirements, the 200 ml pressure wave generator's stroke was extended to achieve 240 ml of swept volume thereby increasing its acoustic power delivery to 4.1 kW without compromising efficiency.
Effect of maternal steroid on developing diaphragm integrity.
Song, Yong; Demmer, Denise L; Pinniger, Gavin J; Lavin, Tina; MacMillan, Mia V; Pillow, Jane J; Bakker, Anthony J
Antenatal steroids reduce the severity of initial respiratory distress of premature newborn babies but may have an adverse impact on other body organs. The study aimed to examine the effect of maternal steroids on postnatal respiratory muscle function during development and elucidate the mechanisms underlying the potential myopathy in newborn rats. Pregnant rats were treated with intramuscular injections of 0.5 mg/kg betamethasone 7 d and 3 d before birth. Newborn diaphragms were dissected for assessment of contractile function at 2 d, 7 d or 21 d postnatal age (PNA), compared with age-matched controls. The expression of myosin heavy chain (MHC) isoforms and atrophy-related genes and activity of intracellular molecular signalling were measured using quantitative PCR and/or Western blot. With advancing PNA, neonatal MHC gene expression decreased progressively while MHC IIb and IIx isoforms increased. Protein metabolic signalling showed high baseline activity at 2 d PNA, and significantly declined at 7 d and 21 d. Antenatal administration of betamethasone significantly decreased diaphragm force production, fatigue resistance, total fast fibre content and anabolic signalling activity (Akt and 4E-BP1) in 21 d diaphragm. These responses were not observed in 2 d or 7 d postnatal diaphragm. Results demonstrate that maternal betamethasone treatment causes postnatal diaphragmatic dysfunction at 21 d PNA, which is attributed to MHC II protein loss and impairment of the anabolic signalling pathway. Developmental modifications in MHC fibre composition and protein signalling account for the age-specific diaphragm dysfunction. PMID:24681552
The diaphragm as an anatomic surrogate for lung tumor motion
NASA Astrophysics Data System (ADS)
Cerviño, Laura I.; Chao, Alvin K. Y.; Sandhu, Ajay; Jiang, Steve B.
Lung tumor motion due to respiration poses a challenge in the application of modern three-dimensional conformal radiotherapy. Direct tracking of the lung tumor during radiation therapy is very difficult without implanted fiducial markers. Indirect tracking relies on the correlation of the tumor's motion and the surrogate's motion. The present paper presents an analysis of the correlation between tumor motion and diaphragm motion in order to evaluate the potential use of diaphragm as a surrogate for tumor motion. We have analyzed the correlation between diaphragm motion and superior-inferior lung tumor motion in 32 fluoroscopic image sequences from ten lung cancer patients. A simple linear model and a more complex linear model that accounts for phase delays between the two motions have been used. Results show that the diaphragm is a good surrogate for tumor motion prediction for most patients, resulting in an average correlation factor of 0.94 and 0.98 with each model respectively. The model that accounts for delays leads to an average localization prediction error of 0.8 mm and an error at the 95% confidence level of 2.1 mm. However, for one patient studied, the correlation is much weaker compared to other patients. This indicates that, before using diaphragm for lung tumor prediction, the correlation should be examined on a patient-by-patient basis.
Interstitial space and collagen alterations of the developing rat diaphragm
NASA Technical Reports Server (NTRS)
Gosselin, L. E.; Martinez, D. A.; Vailas, A. C.; Sieck, G. C.
The effect of growth on the relative interstitial space [%total cross-sectional area (CSA)] and collagen content of the rat diaphragm muscle was examined at postnatal ages of 0, 7, 14, and 21 days as well as in adult males. The proportion of interstitial space relative to total muscle CSA was determined by computerized image analysis of lectin-stained cross sections of diaphragm muscle. To assess collagen content and extent of collagen maturation (i.e., cross-linking), high-pressure liquid chromatography analysis was used to measure hydroxyproline concentration and the nonreducible collagen cross-link hydroxylysylpyridinoline (HP), respectively. At birth, interstitial space accounted for approximately 47% of total diaphragm muscle CSA. During postnatal growth, the relative contribution of interstitial space decreased such that by adulthood the interstitial space accounted for approximately 18% of total muscle CSA. The change in relative interstitial space occurred without a concomitant change in hydroxyproline concentration. However, the concentration of HP markedly increased with age such that the adult diaphragm contained approximately 17 times more HP than at birth. These results indicate that during development the relative CSA occupied by interstitial space decreases as muscle fiber size increases. However, the reduction in relative interstitial space is not associated with a change in collagen concentration. Thus collagen density in the interstitial space may increase with age. It is possible that the observed changes in relative interstitial space and collagen influence the passive length-force properties of the diaphragm.
Survey of blood pump diaphragm damage in the NIPRO-ventricular assist device.
Kashiwa, Koichi; Nishimura, Takashi; Nakahata, Aoi; Momose, Naoki; Umeda, Chinori; Kubo, Hitoshi; Tamai, Hisayoshi; Kinugawa, Koichiro; Adachi, Hideo; Yamaguchi, Atsushi; Yambe, Tomoyuki; Katohgi, Toshiyuki; Kyo, Shunei; Ono, Minoru
We surveyed the incidence of blood pump diaphragm damage (rupture or crack) in the NIPRO-ventricular assist device (VAD). In the cases in which rupture or suspected blood pump crack was detected, we disassembled the pumps to visually check the condition of the diaphragm after replacement or use. Of 366 blood pumps surveyed, diaphragm damage was observed in 2.7 %. The duration of use of the blood pumps with diaphragm damage was significantly longer than that of pumps without damage. The incidence of diaphragm damage increased with longer duration of use. On the basis of these findings, blood pump diaphragm damage in the NIPRO-VAD may be associated with duration of use. However, some blood pumps were used for prolonged periods without diaphragm damage. All blood pumps with damage had a crack in the diaphragm on the air chamber side near the diaphragm-housing (D-H) junction. Cracks were not found in any specific part of the diaphragm. In blood pumps with diaphragm rupture, the crack had a through-hole reaching the blood-contacting surface. Although we were unable to identify the causes of the cracks, it is suggested that when a crack appears in the diaphragm it will gradually expand and eventually lead to rupture. If a crack is detected in a blood pump, we advocate replacing the pump before it grows. When the NIPRO-VAD is used, it is necessary to keep in mind that blood pump diaphragm damage may occur. PMID:22923169
A non-diaphragm type small shock tube for application to a molecular beam source
NASA Astrophysics Data System (ADS)
Yoshimoto, Yuta; Osuka, Kenichi; Miyoshi, Nobuya; Kinefuchi, Ikuya; Takagi, Shu; Matsumoto, Yoichiro
A non-diaphragm type small shock tube was developed for application to a molecular beam source, which can generate beams in the energy range from 1 to several electron volts and beams containing dissociated species such as atomic oxygen. Since repetitive high-frequency operation is indispensable for rapid signal acquisition in beam scattering experiments, the dimensions of the shock tube were miniaturized to reduce the evacuation time between shots. The designed shock tube is 2-4 mm in diameter and can operate at 0.5 Hz. Moreover, a high shock Mach number at the tube end is required for high-energy molecular beam generation. To reduce the shock attenuation caused by the wall boundary layer, which becomes significant in small-diameter tubes, we developed a high-speed response valve employing the current-loop mechanism. The response time of this mechanism is about 100 μs, which is shorter than the rupture time of conventional diaphragms. We show that the current-loop valve generates shock waves with shorter formation distances (about 200-300 mm) than those of conventional shock tubes. In addition, the converging geometry efficiently accelerates shock wave in the small-diameter tubes. The optimal geometry of the shock tube yields shock Mach number around 7, which indicates that the translation energy of molecular beams can exceed 1 eV even in the presence of the real gas effect.
Modeling of a dielectric elastomer diaphragm for a prosthetic blood pump
NASA Astrophysics Data System (ADS)
Goulbourne, Nakhiah; Frecker, Mary I.; Mockensturm, Eric M.; Snyder, Alan J.
The electromechanical behavior of dielectric elastomers is to be exploited for medical application in artificial blood pumps. It is required that the pump diaphragm achieves a swept volume increase of 70 cc into a systolic pressure of 120 mmHg with the main design objective being volumetric efficiency. As such, a model that accommodates large deformation behavior is used. In order to design prosthetic blood pumps that closely mimic the natural pumping chambers of the heart, a dielectric elastomer diaphragm design is proposed. The elastomer's change in shape in response to the applied electric field will permit it to be the active element of the pump just as the ventricular walls are in the natural heart. A comprehensive analytical model that accounts for the combined elastic and dielectric behavior of the membrane is used to compute the stresses and deformations of the inflated membrane. Dielectric elastomers are often pre-strained in order to obtain optimal electromechanical performance. The resulting model incorporates pre-strain and shows how system parameters such as pre-strain, pressure, electric field, and edge constraints affect membrane deformation. The model predicts more than adequate volume displacement for moderate pre-strain of the elastomer.
Interactive Simulation of Diaphragm Motion Through Muscle and Rib Kinematics
NASA Astrophysics Data System (ADS)
Villard, Pierre-Frédéric; Bourne, Wesley; Bello, Fernando
Modeling of diaphragm behaviour is of relevance to a number of clinical procedures such as lung cancer radiotherapy and liver access interventions. The heterogeneity in tissue composition of the diaphragm, as well as the various physiological phenomena influencing its behaviour, requires a complex model in order to accurately capture its motion. In this chapter we present a novel methodology based on a heterogenous model composed of mass-spring and tensegrity elements. The physiological boundary conditions have been carefully taken into account and applied to our model. Thus, it incorporates the influence of the rib kinematics, the muscle natural contraction/relaxation and the motion of the sternum. Initial validation results show that the behaviour of the model closely follows that of a real diaphragm.
Plasma Discharge Process in a Pulsed Diaphragm Discharge System
NASA Astrophysics Data System (ADS)
Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu
As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.
Facioscapulohumeral muscular dystrophy and respiratory failure; what about the diaphragm?
Hazenberg, A.; van Alfen, N.; Voet, N.B.M.; Kerstjens, H.A.M.; Wijkstra, P.J.
Introduction We present a case of facioscapulohumeral muscular dystrophy (FSHD) with a diaphragm paralysis as the primary cause of ventilatory failure. FSHD is an autosomal dominant inherited disorder with a restricted pattern of weakness. Although respiratory weakness is a relatively unknown in FSHD, it is not uncommon. Methods We report on the clinical findings of a 68-year old male who presented with severe dyspnea while supine. Results Supplementing our clinical findings with laboratory, electrophysiological and radiological performances led to the diagnosis of diaphragm paralysis. Arterial blood gas in sitting position without supplemental oxygen showed a mild hypercapnia. His sleep improved after starting non-invasive ventilation and his daytime sleepiness disappeared. Discussion We conclude that in patients with FSHD who have symptoms of nocturnal hypoventilation, an adequate assessment of the diaphragm is recommended. This is of great importance as we know that nocturnal hypoventilation can be treated effectively by non-invasive ventilation. PMID:26029575
[Pleuroperitoneal communication due to diaphragmatic injury as a complication of chest wall resection in a peritoneal dialysis patient; report of a case].
Kanauchi, Naoki; Oizumi, H; Kato, H; Endo, M; Sadahiro, M
A 78-year-old female undergoing peritoneal dialysis due to chronic renal failure was admitted to our hospital because of a tumor on her right chest wall. The diagnosis was recurrence of hepatocellular carcinoma in the thoracic wall, and a combined resection of the thoracic wall and diaphragm was performed. Peritoneal dialysis was resumed 7 days after surgery, but a right pleural effusion was observed after 6 days of dialysis. Surgery was performed because failure of sutures related to the excised diaphragm was suspected. A thoracotomy revealed a large defect, about 1 cm in size, caused by injury of the diaphragm by an edge of the resected rib at the another site of a previous resection of the diaphragm. This defect was closed with sutures and the diaphragm was reinforced with a polyglycolic acid felt and fibrin glue. Peritoneal dialysis was resumed 7 days after surgery and has continued to date without recurrence. PMID:19764505
Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?
Yang, Juan; Cai, Jing; Wang, Hongjun; Chang, Zheng; Czito, Brian G.; Bashir, Mustafa R.; Palta, Manisha; Yin, Fang-Fang
Purpose: To evaluate the relationship between liver tumor motion and diaphragm motion. Methods and Materials: Fourteen patients with hepatocellular carcinoma (10 of 14) or liver metastases (4 of 14) undergoing radiation therapy were included in this study. All patients underwent single-slice cine–magnetic resonance imaging simulations across the center of the tumor in 3 orthogonal planes. Tumor and diaphragm motion trajectories in the superior–inferior (SI), anterior–posterior (AP), and medial–lateral (ML) directions were obtained using an in-house-developed normalized cross-correlation–based tracking technique. Agreement between the tumor and diaphragm motion was assessed by calculating phase difference percentage, intraclass correlation coefficient, and Bland-Altman analysis (Diff). The distance between the tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between the 2 motions. Results: Of all patients, the mean (±standard deviation) phase difference percentage values were 7.1% ± 1.1%, 4.5% ± 0.5%, and 17.5% ± 4.5% in the SI, AP, and ML directions, respectively. The mean intraclass correlation coefficient values were 0.98 ± 0.02, 0.97 ± 0.02, and 0.08 ± 0.06 in the SI, AP, and ML directions, respectively. The mean Diff values were 2.8 ± 1.4 mm, 2.4 ± 1.1 mm, and 2.2 ± 0.5 mm in the SI, AP, and ML directions, respectively. Tumor and diaphragm motions had high concordance when the distance between the tumor and tracked diaphragm area was small. Conclusions: This study showed that liver tumor motion had good correlation with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be used as a reliable surrogate for liver tumor motion.
Best Approach and Benefit of Plication for Paralyzed Diaphragm.
Podgaetz, Eitan; Garza-Castillon, Rafael; Andrade, Rafael S
Diaphragmatic eventration and diaphragmatic paralysis are 2 entities with different etiology and pathology, and are often clinically indistinguishable. When symptomatic, their treatment is the same, with the objective to reduce the dysfunctional cephalad excursion of the diaphragm during inspiration. This can be achieved with diaphragmatic plication through the thorax or the abdomen with either open or minimally invasive techniques. We prefer the laparoscopic approach, due to its easy access to the diaphragm and to avoid pain associated with intercostal incisions and instrument use. Short-term and long-term results are excellent with this technique. PMID:27427528
Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm
Wang, Zhihong; Yao, Yingbang; Wang, Xianbin; Yue, Weisheng; Chen, Longqing; Zhang, Xi Xiang
We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr0.52Ti0.48)O3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature. PMID:24185198
Measured opening characteristics of an electromagnetically opened diaphragm for the Langley expansion tunnel
NASA Technical Reports Server (NTRS)
Moore, J. A.
Results from an experimental study of the opening characteristics of an electromagnetically opened, 15.24 cm diameter diaphragm are presented. This diaphragm consists of a polyester film bonded to a preformed wire and is opened by passing a current pulse (capacitor discharge) through the wire. The diaphragm separates the acceleration section of the expansion tunnel from the nozzle so that the nozzle may be at a lower pressure than the acceleration section prior to a test. Opening times and cleanness of the opened area were examined for dependence on diaphragm thickness, on wire diameter, on technique of bonding the wire to the diaphragm, and on voltage and energy level of the energy source. Time histories of the pitot pressure measured at the expansion-tunnel nozzle entrance location are presented for (1) no diaphragm, (2) a flow-opened diaphragm, and (3) an electromagnetically opened diaphragm.
Patho-anatomy of Herniation of the Reticulum Through the Diaphragm in the Bovine
Deshpande, K. S.; Krishnamurthy, D.; Nigam, J. M.; Sharma, D. N.
Dissection of embalmed and untreated water buffalo carcasses (n=10) revealed that hernias had occurred at the musculotendinous junction of the diaphragm, ventral to the foramen venae cavae and slightly lateral to the median plane. The diameter of the hernial ring varied from 7 cm to 20 cm. Herniation was more common in the right thoracic cavity with the reticulum firmly adherent to the hernia ring. Adhesions between the herniated portion of the reticulum and pleura, lung, pericardium or thoracic wall were present, while in a few cases thick fibrous tracts concealing metallic bodies were found. In two cases, involvement of esophageal groove with malalignment of cardia and reticulo-omasal opening was observed. Displacement and compression of the heart was observed in four animals. ImagesFigure 1.Figure 2.Figure 3. PMID:7340924
Phrenic Nerve Stimulation for Diaphragm Pacing in a Quadriplegic Patient
Kim, Deog-ryung; Kim, Il-sup; Hong, Jae Taek
Chronic hypoventilation due to injury to the brain stem respiratory center or high cervical cord (above the C3 level) can result in dependence to prolonged mechanical ventilation with tracheostomy, frequent nosocomial pneumonia, and prolonged hospitalization. Diaphragm pacing through electrical stimulation of the phrenic nerve is an established treatment for central hypoventilation syndrome. We performed chronic phrenic nerve stimulation for diaphragm pacing with the spinal cord stimulator for pain control in a quadriplegic patient with central apnea due to complete spinal cord injury at the level of C2 from cervical epidural hematoma. After diaphragmatic pacing, the patient who was completely dependent on the mechanical ventilator could ambulate up to three hours every day without aid of mechanical ventilation during the 12 months of follow-up. Diaphragm pacing through unilateral phrenic nerve stimulation with spinal cord stimulator was feasible in an apneic patient with complete quadriplegia who was completely dependent on mechanical ventilation. Diaphragm pacing with the spinal cord stimulator is feasible and effective for the treatment of the central hypoventilation syndrome. PMID:24294464
21 CFR 884.5350 - Contraceptive diaphragm and accessories.
Code of Federal Regulations, 2013 CFR
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Contraceptive diaphragm and accessories. 884.5350 Section 884.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES.... This generic type of device may include an introducer. (b) Classification. Class II...
21 CFR 884.5350 - Contraceptive diaphragm and accessories.
Code of Federal Regulations, 2014 CFR
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Contraceptive diaphragm and accessories. 884.5350 Section 884.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES.... This generic type of device may include an introducer. (b) Classification. Class II...
21 CFR 884.5350 - Contraceptive diaphragm and accessories.
Code of Federal Regulations, 2010 CFR
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contraceptive diaphragm and accessories. 884.5350 Section 884.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES.... This generic type of device may include an introducer. (b) Classification. Class II...
21 CFR 884.5350 - Contraceptive diaphragm and accessories.
Code of Federal Regulations, 2011 CFR
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Contraceptive diaphragm and accessories. 884.5350 Section 884.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES.... This generic type of device may include an introducer. (b) Classification. Class II...
21 CFR 884.5350 - Contraceptive diaphragm and accessories.
Code of Federal Regulations, 2012 CFR
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Contraceptive diaphragm and accessories. 884.5350 Section 884.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES.... This generic type of device may include an introducer. (b) Classification. Class II...
The role of the diaphragm in trunk extension in tetraplegia.
Sinderby, C; Ingvarsson, P; Sullivan, L; Wickström, I; Lindström, L
Interest has been focused on the diaphragm as the all important respiratory muscle in tetraplegia for decades but its unique role as a trunk extension muscle has not been considered. This study set out to establish the relationship, if any, between the roles of the diaphragm during arm exercise and trunk flexion. Eight male complete cervical cord injuries (CCI) patients, sitting in their wheelchairs, were studied during rest, trunk flexion and start of arm cranking. The average flow, volume, oesophageal and gastric pressures (Poes and Pga) and the myoelectric activity of the diaphragm (EMGdi) were recorded. The EMGdi pattern changed from phasic activity at rest to continuous or almost continuous activity during trunk flexion. Patients were then either spontaneously holding their breath or breathing irregularly with rapid or shallow breaths. Also, the normalised EMGdi signal strength increased by an average of 150% and the mean Pga by about 3 kPa, while mean Poes decreased by about 0.5 kPa. At the start of exercise, patients with poor triceps function, less than MRC grade 3, exhibited similar ventilatory and EMGdi changes as had been seen in trunk flexion. In patients with better triceps function, only minor changes in these variables were observed. The findings suggest that the diaphragm acts both as a trunk extensor muscle and a respiratory muscle. During posture imbalance, the postural needs temporarily override the respiratory needs. PMID:1635787
Die and telescoping punch form convolutions in thin diaphragm
NASA Technical Reports Server (NTRS)
Die and punch set forms convolutions in thin dished metal diaphragm without stretching the metal too thin at sharp curvatures. The die corresponds to the metal shape to be formed, and the punch consists of elements that progressively slide against one another under the restraint of a compressed-air cushion to mate with the die.
28. Spans 25, detail view, easternmost diaphragm between southern and ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
28. Spans 2-5, detail view, easternmost diaphragm between southern and central lines of spandrel arches of Span 5; view to west. - Fifth Street Bridge, Spanning MBTA Fitchburg Commuter Rail Line tracks, Conrail Fitchburg Secondary Line & North Nashua River, Fitchburg, Worcester County, MA
14 CFR 121.251 - Engine accessory section diaphragm.
Code of Federal Regulations, 2011 CFR
... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and...
Design of fabric preforms for double diaphragm forming
NASA Technical Reports Server (NTRS)
Luby, Steven; Bernardon, Edward
Resin Transfer Molding (RTM) has the potential of becoming one of the most cost effective ways of producing composite structures since the raw materials used, resin and dry fabric, are less costly than prepregs. Unfortunately these low material costs are offset by the high labor costs incurred to layup the dry fabric into 3D shapes. To reduce the layup costs, double diaphragm forming is being investigated as a potential technique for creating a complex 3D preform from a simple flat layup. As part of our effort to develop double diaphragm forming into a production capable process, we have undertaken a series of experiments to investigate the interactions between process parameters, mold geometry, fabric weave, tow size, and the quality of the formed part. The results of these tests will be used to determine the forming geometry limitations of double diaphragm forming and to characterize the formability of fabric configurations. An important part of this work was the development of methods to measure and analyze fiber orientations, deformation angles, tow spreading, and shape conformation of the formed parts. This paper will describe the methods used to mark plies, the double diaphragm forming process, the techniques used to measure the formed parts, and the calculation of the parameters of interest. The results can be displayed as 3D contour plots. These experimental results have also been used to verify and improve a computer model which simulates the draping of fabrics over 3D mold shapes.
14 CFR 121.251 - Engine accessory section diaphragm.
Code of Federal Regulations, 2012 CFR
... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and...
14 CFR 121.251 - Engine accessory section diaphragm.
Code of Federal Regulations, 2013 CFR
... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and...
Diaphragm activation during exercise in chronic obstructive pulmonary disease.
Sinderby, C; Spahija, J; Beck, J; Kaminski, D; Yan, S; Comtois, N; Sliwinski, P
Although it has been postulated that central inhibition of respiratory drive may prevent development of diaphragm fatigue in patients with chronic obstructive pulmonary disease (COPD) during exercise, this premise has not been validated. We evaluated diaphragm electrical activation (EAdi) relative to maximum in 10 patients with moderately severe COPD at rest and during incremental exhaustive bicycle exercise. Flow was measured with a pneumotachograph and volume by integration of flow. EAdi and transdiaphragmatic pressures (Pdi) were measured using an esophageal catheter. End-expiratory lung volume (EELV) was assessed by inspiratory capacity (IC) maneuvers, and maximal voluntary EAdi was obtained during these maneuvers. Minute ventilation (V E) was 12.2 +/- 1.9 L/min (mean +/- SD) at rest, and increased progressively (p < 0.001) to 31.0 +/- 7.8 L/min at end-exercise. EELV increased during exercise (p < 0.001) causing end-inspiratory lung volume to attain 97 +/- 3% of TLC at end-exercise. Pdi at rest was 9.4 +/- 3.2 cm H(2)O and increased during the first two thirds of exercise (p < 0.001) to plateau at about 13 cm H(2)O. EAdi was 24 +/- 6% of voluntary maximal at rest and increased progressively during exercise (p < 0.001) to reach 81 +/- 7% at end-exercise. In conclusion, dynamic hyperinflation during exhaustive exercise in patients with COPD reduces diaphragm pressure-generating capacity, promoting high levels of diaphragm activation. PMID:11401887
Is polysomnographic examination necessary for subjects with diaphragm pathologies?
Oruc, Ozlem; Sarac, Sema; Afsar, Gulgun Cetintas; Topcuoglu, Ozgur Bilgin; Kanbur, Serda; Yalcinkaya, Irfan; Tepetam, Fatma Merve; Kirbas, Gokhan
OBJECTIVES: While respiratory distress is accepted as the only indication for diaphragmatic plication surgery, sleep disorders have been underestimated. In this study, we aimed to detect the sleep disorders that accompany diaphragm pathologies. Specifically, the association of obstructive sleep apnea syndrome with diaphragm eventration and diaphragm paralysis was evaluated. METHODS: This study was performed in Süreyyapasa Chest Diseases and Thoracic Surgery Training and Research Hospital between 2014–2016. All patients had symptoms of obstructive sleep apnea (snoring and/or cessation of breath during sleep and/or daytime sleepiness) and underwent diaphragmatic plication via video-assisted mini-thoracotomy. Additionally, all patients underwent pre- and postoperative full-night polysomnography. Pre- and postoperative clinical findings, polysomnography results, Epworth sleepiness scale scores and pulmonary function test results were compared. RESULTS: Twelve patients (7 males) with a mean age of 48 (range, 27-60) years and a mean body mass index of 25 (range, 20-30) kg/m2 were included in the study. Preoperative polysomnography showed obstructive sleep apnea syndrome in 9 of the 12 patients (75%), while 3 of the patients (25%) were regarded as normal. Postoperatively, patient complaints, apnea hypopnea indices, Epworth sleepiness scale scores and pulmonary function test results all demonstrated remarkable improvement. CONCLUSION: All patients suffering from diaphragm pathologies with symptoms should undergo polysomnography, and patients diagnosed with obstructive sleep apnea syndrome should be operated on. In this way, long-term comorbidities of sleep disorders may be prevented.
14 CFR 121.251 - Engine accessory section diaphragm.
Code of Federal Regulations, 2010 CFR
... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and...
[Cellular homogeneity in diverse portions of the diaphragm].
Jiménez-Fuentes, M A; Gea, J; Mariñán, M; Gáldiz, J B; Gallego, F; Broquetas, J M
The diaphragm is the main inspiratory muscle. It is composed of two parts, the costal and crural, with both anatomical and functional differences. The general morphometric characteristics of the diaphragm have been described in various species but homogeneity throughout the muscle has not been adequately studied. The aim of this study was to evaluate the fiber phenotype of various parts of the diaphragm. The entire diaphragm muscles of five New Zealand rabbits were removed and each was divided into quarters. The specimens were processed for morphometry (hematoxyllineosin stains, NADH-TR and ATPase at pH levels of 4.2, 4.6 and 9.4). For each portion we measured percent and size of fibers, expressing the latter as minimum diameter (Dm), measured area (Ar) and calculated area (Ac). Left and right diaphragm hemispheres (20 portions examined) were similar for fiber percentages and sizes. For left and right halves, respectively 50 +/- 2 and 51 +/- 4% of fibers were type I; type I Dm measurements were 38 +/- 5 and 41 +/- 4 microns; type I Ar values were 1798 +/- 481 and 2030 +/- 390 micron 2; type I Ac values were 1181 +/- 360 and 1321 +/- 382 micron 2; type II Dm values were 46 +/- 4 and 46 +/- 5 microns; type II Ar values were 2466 +/- 388 micron 2 and 2539 +/- 456 micron 2; type II Ac data were 1642 +/- 255 and 1655 +/- 382 micron 2. We likewise found no differences between costal and crural portions of the muscle (n = 20). For costal and crural portions, respectively, 50 +/- 3 and 50 +/- 2% of fibers were type I; type I Dm sizes were 39 +/- 5 and 40 +/- 4 microns; type I Ar measurements were 1859 +/- 521 and 1964 +/- 365 micron 2; type I Ac figures were 1231 +/- 317 and 1266 +/- 288 micron 2; type II Dm were 47 +/- 4 and 44 +/- 3 microns; type II Ar were 2563 +/- 481 and 2430 +/- 331 micron 2; type II Ac were 1729 +/- 373 and 1557 +/- 212 micron 2. Type II fibers, however, were somewhat larger than type I fibers in all portions (p = 0.001). New Zealand rabbit
Hyperglycemia-induced diaphragm weakness is mediated by oxidative stress
Introduction A major consequence of ICU-acquired weakness (ICUAW) is diaphragm weakness, which prolongs the duration of mechanical ventilation. Hyperglycemia (HG) is a risk factor for ICUAW. However, the mechanisms underlying HG-induced respiratory muscle weakness are not known. Excessive reactive oxygen species (ROS) injure multiple tissues during HG, but only one study suggests that excessive ROS generation may be linked to HG-induced diaphragm weakness. We hypothesized that HG-induced diaphragm dysfunction is mediated by excessive superoxide generation and that administration of a specific superoxide scavenger, polyethylene glycol superoxide dismutase (PEG-SOD), would ameliorate these effects. Methods HG was induced in rats using streptozotocin (60 mg/kg intravenously) and the following groups assessed at two weeks: controls, HG, HG + PEG-SOD (2,000U/kg/d intraperitoneally for seven days), and HG + denatured (dn)PEG-SOD (2000U/kg/d intraperitoneally for seven days). PEG-SOD and dnPEG-SOD were administered on day 8, we measured diaphragm specific force generation in muscle strips, force-pCa relationships in single permeabilized fibers, contractile protein content and indices of oxidative stress. Results HG reduced diaphragm specific force generation, altered single fiber force-pCa relationships, depleted troponin T, and increased oxidative stress. PEG-SOD prevented HG-induced reductions in diaphragm specific force generation (for example 80 Hz force was 26.4 ± 0.9, 15.4 ± 0.9, 24.0 ± 1.5 and 14.9 ± 0.9 N/cm2 for control, HG, HG + PEG-SOD, and HG + dnPEG-SOD groups, respectively, P <0.001). PEG-SOD also restored HG-induced reductions in diaphragm single fiber force generation (for example, Fmax was 182.9 ± 1.8, 85.7 ± 2.0, 148.6 ± 2.4 and 90.9 ± 1.5 kPa in control, HG, HG + PEG-SOD, and HG + dnPEG-SOD groups, respectively, P <0.001). HG-induced troponin T depletion, protein nitrotyrosine formation
An Investigation of the Characteristics of Steel Diaphragms for Automatic Fuel-Injection Valves
NASA Technical Reports Server (NTRS)
Joachim, W F
This research on steel diaphragms was undertaken at the Langley Memorial Aeronautical Laboratory, as a part of a general investigation on fuel injection engines for aircraft. The work determined the load-deflection, load- deformation and hysteresis characteristics for single diaphragms having thicknesses from 0.00s inch to 0.012 inch, and for similar diaphragms tested in multiple having total thicknesses from 0.012 inch to 0.180 inch. The elastic limit loads and deflections, and rupture points of single diaphragms were also determined. Some work was done on diaphragms having central orifices in order to determine the effect of orifice diameter upon the load deflection characteristics.
Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation
Seven, Yasin B.; Mantilla, Carlos B.
Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P < 0.01). During airway occlusion, central drive was ∼3 times greater, motor units were recruited ∼30 ms earlier (P < 0.01), and motor unit onset discharge frequencies were significantly higher (P < 0.01). Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited <20 ms apart. These results are consistent with DIAm motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. PMID:25257864
Diaphragm strength in near-miss sudden infant death syndrome.
Scott, C B; Nickerson, B G; Sargent, C W; Dennies, P C; Platzker, A C; Keens, T G
Diaphragm muscle strength was measured as maximal transdiaphragmatic pressure during airway occlusion in ten near-miss sudden infant death syndrome infants aged 4.1 +/- 0.6 (SE) months post-term, range 2 to 7 months, and ten control infants aged 4.5 +/- 0.8 months post-term, range 0.8 to 8 months. In the near-miss sudden infant death syndrome group, the mean maximal transdiaphragmatic pressure was 106 +/- 6 cm H2O, range 78 to 132 cm H2O, compared with a mean maximal transdiaphragmatic pressure 86 +/- 4 cm H2O, range 69 to 106 cm H2O, in the control group. Diaphragm strength is normal or increased in near-miss sudden infant death syndrome infants. PMID:7079044
Coupling Impedance of a Periodic Array of Diaphragms (Erratum)
Stupakov, G.V.; /SLAC
A method is presented for calculating the high-frequency longitudinal and transverse coupling impedances in a periodic array of diaphragms in a circular perfectly conducting pipe. The method is based on Weinstein's theory of diffraction of a plane electromagnetic wave on a stack of halfplanes. Using Weinstein's solution, it is shown that the problem of finding the beam field in the pipe reduces to an effective boundary condition at the radius of the diaphragms that couples the longitudinal electric field with the azimuthal magnetic one. Solving Maxwell's equations with this boundary condition leads to simple formulae for Z{sub long} and Z{sub tr}. A good agreement with a numerical solution of the problem found by other authors is demonstrated.
Coupling impedance of a periodic array of diaphragms
Stupakov, G.V.
A method is presented for calculating the high-frequency longitudinal and transverse coupling impedances in a periodic array of diaphragms in a circular perfectly conducting pipe. The method is based on Weinstein`s theory of diffraction of a plane electromagnetic wave on a stack of halfplanes. Using Weinstein`s solution, it is shown that the problem of finding the beam field in the pipe reduces to an effective boundary condition at the radius of the diaphragms that couples the longitudinal electric field with the azimuthal magnetic one. Solving Maxwell`s equations with this boundary condition leads to simple formulae for Z{sub long} and Z{sub tr}. A good agreement with a numerical solution of the problem found by other authors is demonstrated.
Fabry-Perot diaphragm fiber-optic sensor.
Chin, Ken K; Sun, Yan; Feng, Guanhua; Georgiou, George E; Guo, Kangzhu; Niver, Edip; Roman, Harry; Noe, Karen
The general theory of a diaphragm fiber-optic sensor (DFOS) is proposed. We use a critical test to determine if a DFOS is based on Fabry-Perot interference or intensity modulation. By use of the critical test, this is the first design, to the best of our knowledge, of a purely Fabry-Perot DFOS, fabricated with microelectromechanical system technology, and characterized as an audible microphone and ultrasonic hydrophone with orders of improvement in signal-to-noise ratio. PMID:17973004
Diaphragm forming of carbon-fiber-reinforced thermoplastic composite materials
Smiley, A.J.
The experimental work consisted of fabricating composite components and identifying the effects of the forming parameters on the resulting thickness profiles and fiber orientation. The transverse fiber flow produced thickness variations and fiber-orientation fields peculiar to the tool-surface geometry, diaphragm deformation behavior, and laminate configuration. The transverse flow in the surface-ply layers was dominated by the stretching diaphragms. In the interior ply layers the flow appeared to be driven by the pressure gradients produced at the contact points. The analytical work consisted of the development of a diaphragm-forming process model which employed engineering mechanics and fiber kinematics to predict post-formed thickness variations and fiber orientation fields of axisymmetric composite components. The flow analysis determined the thickness variation and flow velocities in the transverse fiber direction. The flow velocities were employed to determine the relative fiber realignment. The realignment of the fibers was then utilized in a geometric mapping procedure to determine the fiber-orientation field. Overall, the predictions on interior-ply and surface-ply layer orientations matched reasonably well with the experimental observations.
Vagal afferents, diaphragm fatigue, and inspiratory resistance in anesthetized dogs.
Adams, J M; Farkas, G A; Rochester, D F
This study tests three hypotheses regarding mechanisms that produce rapid shallow breathing during a severe inspiratory resistive load (IRL): 1) an intact vagal afferent pathway is necessary; 2) diaphragm fatigue contributes to tachypnea; and 3) hypoxia may alter the pattern of respiration. We imposed a severe IRL on pentobarbital sodium-anesthetized dogs, followed by bilateral vagotomy, then by supplemental O2. IRL alone produced rapid shallow breathing associated with hypercapnia and hypoxia. After the vagotomy, the breathing pattern became slow and deep, restoring arterial PCO2 but not arterial PO2 toward the control values. Relief of hypoxia had no effect, and at no time was there any evidence of fatigue of the diaphragm as measured by the response to phrenic nerve stimulation. We conclude that an intact afferent vagal pathway is necessary for the tachypnea resulting from a severe IRL, neither hypoxia nor diaphragm fatigue played a role, and, although we cannot rule out stimulation of vagal afferents, the simplest explanation for the increased frequency in our experiments is increased respiratory drive due to hypercapnia. PMID:3136122
PO2 Cycling Reduces Diaphragm Fatigue by Attenuating ROS Formation
Zuo, Li; Diaz, Philip T.; Chien, Michael T.; Roberts, William J.; Kishek, Juliana; Best, Thomas M.; Wagner, Peter D.
Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses. PMID:25299212
SU8 diaphragm micropump with monolithically integrated cantilever check valves.
Ezkerra, Aitor; Fernández, Luis José; Mayora, Kepa; Ruano-López, Jesús Miguel
This paper presents a SU8 unidirectional diaphragm micropump with embedded out-of-plane cantilever check valves. The device represents a reliable and low-cost solution for integration of microfluidic control in lab-on-a-chip devices. Its planar architecture allows monolithic definition of its components in a single step and potential integration with previously reported PCR, electrophoresis and flow-sensing SU8 microdevices. Pneumatic actuation is applied on a PDMS diaphragm, which is bonded to the SU8 body at wafer level, further enhancing its integration and mass production capabilities. The cantilever check valves move synchronously with the diaphragm, feature fast response (10ms), low dead volume (86nl) and a 94% flow blockage up to 300kPa. The micropump achieves a maximum flow rate of 177 μl min(-1) at 6 Hz and 200 kPa with an effective area of 10 mm(2). The device is reliable, self-priming and tolerant to particles and big bubbles. To the knowledge of the authors, this is the first micropump in SU8 with monolithically integrated cantilever check valves. PMID:21853192
Integrated Optical Interferometers with Micromachined Diaphragms for Pressure Sensing
NASA Technical Reports Server (NTRS)
DeBrabander, Gregory N.; Boyd, Joseph T.
Optical pressure sensors have been fabricated which use an integrated optical channel waveguide that is part of an interferometer to measure the pressure-induced strain in a micromachined silicon diaphragm. A silicon substrate is etched from the back of the wafer leaving a rectangular diaphragm. On the opposite side of the wafer, ring resonator and Mach-Zehnder interferometers are formed with optical channel waveguides made from a low pressure chemical vapor deposited film of silicon oxynitride. The interferometer's phase is altered by pressure-induced stress in a channel segment positioned over the long edge of the diaphragm. The phase change in the ring resonator is monitored using a link-insensitive swept frequency laser diode, while in the Mach-Zehnder it is determined using a broad band super luminescent diode with subsequent wavelength separation. The ring resonator was found to be highly temperature sensitive, while the Mach-Zehnder, which had a smaller optical path length difference, was proportionally less so. The quasi-TM mode was more sensitive to pressure, in accord with calculations. Waveguide and sensor theory, sensitivity calculations, a fabrication sequence, and experimental results are presented.
Kinematic modeling of single muscle fiber during diaphragm shortening.
Kyckelhahn, Brian A; Nason, Patricia B; Tidball, James G; Boriek, Aladin M
Understanding the kinematics of the diaphragm muscle at the single fiber level is important in understanding the mechanics of its membrane. Nevertheless, the geometric parameters of single muscle fiber contraction remain poorly understood. We modeled the kinematics of a single muscle fiber of the diaphragm to determine the relationships among fiber shape, perimeter of the fiber cross-section, and apparent surface area of the fiber during muscle shortening. We used the models to identify which constraints on the geometric parameters are most consistent with physiological data on diaphragmatic muscle shortening. Our kinematic models use isovolumic fibers with elliptical cross-sections, and these models have the following properties: (1) constant cross-sectional shape, (2) inextensible cross-sectional perimeter, (3) constant cross-sectional transverse dimension, or (4) constant apparent surface area. These models were investigated during muscle shortening of the diaphragm from functional residual capacity to total lung capacity. The model that matches physiologic data best has zero transverse strain and has a relationship between fiber shape and muscle shortening consistent with published data on single muscle fiber mechanics. PMID:12594994
Potential for revitalisation of the diaphragm for family planning in Uganda: a rapid assessment of the feasibility of introducing the SILCS Diaphragm.
Kyamwanga, Imelda T; Turyakira, Eleanor; Kilbourne-Brook, Maggie; Coffey, Patricia S
This health systems assessment evaluated the feasibility of introducing a new contraceptive device, the SILCS single-size diaphragm, into the existing family planning method mix in Uganda. A total of 26 focus group discussions with 201 female and 77 male potential users and 98 key informant interviews with policymakers and providers were conducted between June and August 2010. Potential users, providers, and policymakers recognised that the SILCS Diaphragm could fill a gap in the method mix and expressed eagerness to make the SILCS Diaphragm available, particularly because it is nonhormonal and woman initiated. The diaphragm was viewed by all stakeholders as a method that would increase choice and could improve women's reproductive health in Uganda. Like many countries, Uganda's family planning programme is financially stretched, and clear support for the SILCS Diaphragm by end-users will need to be demonstrated before the product will be considered for public-sector introduction. PMID:25022144
Muscle connective tissue controls development of the diaphragm and is a source of congenital diaphragmatic hernias
Merrell, Allyson J.; Ellis, Benjamin J.; Fox, Zachary D.; Lawson, Jennifer A.; Weiss, Jeffrey A.; Kardon, Gabrielle
The diaphragm is an essential mammalian skeletal muscle, and defects in diaphragm development are the cause of congenital diaphragmatic hernias (CDH), a common and often lethal birth defect. The diaphragm is derived from multiple embryonic sources, but how these give rise to the diaphragm is unknown and, despite the identification of many CDH-associated genes, the etiology of CDH is incompletely understood. Using mouse genetics, we show that the pleuroperitoneal folds (PPFs), transient embryonic structures, are the source of the diaphragm's muscle connective tissue, regulate muscle development, and their striking migration controls diaphragm morphogenesis. Furthermore, Gata4 mosaic mutations in PPF-derived muscle connective tissue fibroblasts result in the development of localized amuscular regions that are biomechanically weaker and more compliant and lead to CDH. Thus the PPFs and muscle connective tissue are critical for diaphragm development and mutations in PPF-derived fibroblasts are a source of CDH. PMID:25807280
Variability in Diaphragm Motion During Normal Breathing, Assessed With B-Mode Ultrasound
Harper, Caitlin J; Shahgholi, Leili; Cieslak, Kathryn; Hellyer, Nathan J.; Strommen, Jeffrey A.; Boon, Andrea J.
STUDY DESIGN Clinical measurement, cross-sectional. OBJECTIVES To establish a set of normal values for diaphragm thickening with tidal breathing in healthy subjects. BACKGROUND Normal values for diaphragm contractility, as imaged sonographically, have not been described, despite the known role of the diaphragm in contributing to spinal stability. If the normal range of diaphragm contractility can be defined in a reliable manner, ultrasound has the potential to be used clinically and in research as a biofeedback tool to enhance diaphragm activation/contractility. METHODS B-mode ultrasound was performed on 150 healthy subjects to visualize and measure hemi-diaphragm thickness on each side at resting inspiration and expiration. Primary outcome measures were hemi-diaphragm thickness and thickening ratio, stratified for age, gender, and body mass index. Interrater and intrarater reliability were also measured. RESULTS Normal thickness of the diaphragm at rest ranged from 0.12 to 1.18 cm, with slightly greater thickness in men but no effect of age. Average ± SD change in thickness from resting expiration to resting inspiration was 20.0% ± 15.5% on the right and 23.5% ± 24.4% on the left; however, almost one third of healthy subjects had no to minimal diaphragm thickening with tidal breathing. CONCLUSION There is wide variability in the degree of diaphragm contractility during quiet breathing. B-mode ultrasound appears to be a reliable means of determining the contractility of the diaphragm, an important muscle in spinal stability. Further studies are needed to validate this imaging modality as a clinical tool in the neuromuscular re-education of the diaphragm to improve spinal stability in both healthy subjects and in patients with low back pain. PMID:24175600
Diameter and position effect determination of diaphragm on hybrid rocket motor
NASA Astrophysics Data System (ADS)
Sun, Xingliang; Tian, Hui; Cai, Guobiao
This study is aimed to determine and better reveal the mixture enhancement and regression rate distribution of hybrid rocket motor with diaphragm by numerical approach. A numerical model based on the computational fluid dynamics software is built to simulate the flow and combustion inside the motor. Four firing tests of the motor, including one without diaphragm and three with diaphragm, are conducted on a standard experimental system and also used as a reference for numerical simulation, the consistency between the simulation and experiment demonstrates that the numerical approach is an effective method to study the diaphragm effect on the motor performance. The flow field characteristic and regression rate distribution inside the hybrid rocket motor are then calculated to analyze the effect of position and diameter of the diaphragm. The results indicate that the diaphragm almost have no effect on the regression rate before it. However, the regression rate after the diaphragm has a strong dependence on the position and diameter of the diaphragm. As the diameter decreases and the position moves backward, the regression rate increases larger and larger, this is mainly due to the augmentation of the eddy generated by the diaphragm, which enhances the heat feedback transferred to the grain surface. When the diameter of diaphragm located at middle of grain decreases from 50 mm to 20 mm, regression rate is increased from 0.30 mm/s to 0.57 mm/s. The use of the diaphragm does cause a combustion efficiency improvement; the maximum combustion efficiency is enhanced to 98.9% from lower than 90% of the motor with no diaphragm. The increasing amplitude displays a square relation with the diameter decrease, since the entrainment of the eddy make the reactants mix sufficiently to release more energy inside the motor.
Blockage of the Ryanodine Receptor via Azumolene Does Not Prevent Mechanical Ventilation-Induced Diaphragm Atrophy
Talbert, Erin E.; Smuder, Ashley J.; Kwon, Oh Sung; Sollanek, Kurt J.; Wiggs, Michael P.; Powers, Scott K.
Mechanical ventilation (MV) is a life-saving intervention for patients in respiratory failure. However, prolonged MV causes the rapid development of diaphragm muscle atrophy, and diaphragmatic weakness may contribute to difficult weaning from MV. Therefore, developing a therapeutic countermeasure to protect against MV-induced diaphragmatic atrophy is important. MV-induced diaphragm atrophy is due, at least in part, to increased production of reactive oxygen species (ROS) from diaphragm mitochondria and the activation of key muscle proteases (i.e., calpain and caspase-3). In this regard, leakage of calcium through the ryanodine receptor (RyR1) in diaphragm muscle fibers during MV could result in increased mitochondrial ROS emission, protease activation, and diaphragm atrophy. Therefore, these experiments tested the hypothesis that a pharmacological blockade of the RyR1 in diaphragm fibers with azumolene (AZ) would prevent MV-induced increases in mitochondrial ROS production, protease activation, and diaphragmatic atrophy. Adult female Sprague-Dawley rats underwent 12 hours of full-support MV while receiving either AZ or vehicle. At the end of the experiment, mitochondrial ROS emission, protease activation, and fiber cross-sectional area were determined in diaphragm muscle fibers. Decreases in muscle force production following MV indicate that the diaphragm took up a sufficient quantity of AZ to block calcium release through the RyR1. However, our findings reveal that AZ treatment did not prevent the MV-induced increase in mitochondrial ROS emission or protease activation in the diaphragm. Importantly, AZ treatment did not prevent MV-induced diaphragm fiber atrophy. Thus, pharmacological inhibition of the RyR1 in diaphragm muscle fibers is not sufficient to prevent MV-induced diaphragm atrophy. PMID:26849371
Application of Microsecond Voltage Pulses for Water Disinfection by Diaphragm Electric Discharge
NASA Astrophysics Data System (ADS)
Kakaurov, S. V.; Suvorov, I. F.; Yudin, A. S.; Solovyova, T. L.; Kuznetsova, N. S.
The paper presents the dependence of copper and silver ions formation on the duration of voltage pulses of diaphragm electric discharge and on the pH of treated liquid medium. Knowing it allows one to create an automatic control system to control bactericidal agent's parameters obtained in diaphragm electric discharge reactor. The current-voltage characteristic of the reactor with a horizontal to the diaphragm membrane water flow powered from the author's custom pulse voltage source is also presented. The results of studies of the power consumption of diaphragm electric discharge depending on temperature of the treated liquid medium are given.
Injury of the human diaphragm associated with exertion and chronic obstructive pulmonary disease.
Orozco-Levi, M; Lloreta, J; Minguella, J; Serrano, S; Broquetas, J M; Gea, J
Injury of the diaphragm may have clinical relevance having been reported in cases of sudden infant death syndrome or fatal asthma. However, examination of diaphragm injury after acute inspiratory loading has not been reported. The purpose of this study was to determine whether an acute inspiratory overload induces injury of the human diaphragm and to determine if diaphragm from chronic obstructive pulmonary disease (COPD) is more susceptible to injury. Eighteen patients with COPD and 11 control patients with normal pulmonary function (62 +/- 10 yr) undergoing thoracotomy or laparotomy were studied. A threshold inspiratory loading test was performed prior to surgery in a subset of seven patients with COPD and five control patients. Samples of the costal diaphragm were obtained during surgery and processed for electron microscopy analysis. Signs of sarcomere disruption were found in all diaphragm samples. The range of values of sarcomere disruption was wide (density: 2-45 abnormal areas/100 microm(2); area fractions: 1.3-17.3%), significantly higher in diaphragm from patients with COPD (p < 0.05) and with the greatest injury after inspiratory loading. We conclude that sarcomere disruption is common in the human diaphragm, is more evident in patients with COPD, and is higher after inspiratory loading, especially in the diaphragm of those with COPD. PMID:11719318
Spiral electrode d33 mode piezoelectric diaphragm combined with proof mass as energy harvester
NASA Astrophysics Data System (ADS)
Shen, Zhiyuan; Liu, Shuwei; Miao, Jianmin; Woh, Lye Sun; Wang, Zhihong
The paper demonstrates an energy harvester using a freestanding piezoelectric diaphragm combined with a proof mass. The diaphragm bearing double-sided spiral electrodes makes use of the d33 piezoelectric effect to realize energy scavenging. The harvester was fabricated by using a MEMS technique. The energy converting performance of the diaphragm was characterized by a shaker system. Proof masses were combined at the center of the diaphragm to tune the resonance of the harvester for the sake of scavenging low frequency vibrational energy. A receptance model was built to explain the vibrational behavior of the combined system. The resonance tuning and energy harvesting performance of the combination system was experimentally verified.
A Study of Free-Piston Double-Diaphragm Drivers for Expansion Tubes. Report 1
NASA Technical Reports Server (NTRS)
Kendall, M. A.
In recent years the free-piston double-diaphragm driver has been used to increase the performance of the XI pilot expansion tube to super-orbital test conditions. However, the actual performance of the double-diaphragm driver was found to be considerably less than ideal. An experimental study of the double-diaphragm driver was carried out on the XI facility over a range of conditions with the objective of determining the effect of. heat losses; and the non-ideal rupture of the 'light' secondary diaphragm on the driver performance. The disparity between the theoretical and measured performance envelope are highlighted. A viscous limit for the experiments vas established. Heat transfer behind the primary shock is shown to be the mechanism behind this limit Incident, reflected and transmitted shock trajectories for the secondary diaphragm were experimentally determined and compared with computed trajectories from a one-dimensional diaphragm inertia model. It was found that the diaphragm did influence the unsteady expansion. A good agreement between experimental and computed shock trajectories was obtained using a diaphragm inertia model assuming that the diaphragm mass became negligible 3 microns after shock impact.
Biomimetic optical directional microphone with structurally coupled diaphragms
NASA Astrophysics Data System (ADS)
Liu, H. J.; Yu, M.; Zhang, X. M.
A biomimetic directional microphone based on structurally coupled diaphragms and a fiber-optic detection system is presented. The microphone design aims to mimic the fly Ormia Ochracea's ear structure and capture its performance. Experiments show that the designed microphone amplifies the interaural time difference (ITD) by 4.4 times and has a directional sensitivity of 6.5 μs/deg. An important finding is that one needs to utilize both the rocking and translational vibration modes to obtain the appropriate ITD amplification without sacrifice of directional sensitivity. This work can serve as a foundation for realizing fly-ear inspired miniature directional microphones.
Familial occurrence of congenital incomplete prepyloric mucosal diaphragm.
Gahukamble, D B
Incomplete prepyloric mucosal diaphragm (IPMD) is an uncommon congenital anomaly that leads to gastric outlet obstruction in infancy and childhood. This report describes the occurrence of IPMD in six children in a closely knit tribal family from a geographically isolated desert town with a small population in the Sahara. Their records showed similarities of clinical, radiological, operative, and histopathological features. These features, as well as its occurrence in brothers, sisters, and cousins, suggest that this unusual anomaly is transmitted as an autosomal recessive trait. Images PMID:9863605
Titanium acoustic diaphragm coated with polycrystal diamond film
Zhiwei Zhang; Zhen Yan; Hesun Zhu
The spherical titanium diaphragm, which is widely used in high frequency loudspeaker, coat with polycrystal diamond film (DF) was prepared for the first time in China by the method of DC arc plasma jet. Its acoustic performance was remarkably upgraded, as confirmed by Raman Shift Spectrum and frequency response curve. Its sensibility was improved by 3-6 dB and frequency widened by 5x10{sup 3}Hz. The frequency range extended from 2.2x10{sup 3}Hz to 25x10{sup 3}Hz. The preparation and process of DF is discussed.
Diaphragm Muscle Fiber Weakness and Ubiquitin–Proteasome Activation in Critically Ill Patients
Hooijman, Pleuni E.; Beishuizen, Albertus; Witt, Christian C.; de Waard, Monique C.; Girbes, Armand R. J.; Spoelstra-de Man, Angelique M. E.; Niessen, Hans W. M.; Manders, Emmy; van Hees, Hieronymus W. H.; van den Brom, Charissa E.; Silderhuis, Vera; Lawlor, Michael W.; Labeit, Siegfried; Stienen, Ger J. M.; Hartemink, Koen J.; Paul, Marinus A.; Heunks, Leo M. A.
Rationale: The clinical significance of diaphragm weakness in critically ill patients is evident: it prolongs ventilator dependency, and increases morbidity and duration of hospital stay. To date, the nature of diaphragm weakness and its underlying pathophysiologic mechanisms are poorly understood. Objectives: We hypothesized that diaphragm muscle fibers of mechanically ventilated critically ill patients display atrophy and contractile weakness, and that the ubiquitin–proteasome pathway is activated in the diaphragm. Methods: We obtained diaphragm muscle biopsies from 22 critically ill patients who received mechanical ventilation before surgery and compared these with biopsies obtained from patients during thoracic surgery for resection of a suspected early lung malignancy (control subjects). In a proof-of-concept study in a muscle-specific ring finger protein-1 (MuRF-1) knockout mouse model, we evaluated the role of the ubiquitin–proteasome pathway in the development of contractile weakness during mechanical ventilation. Measurements and Main Results: Both slow- and fast-twitch diaphragm muscle fibers of critically ill patients had approximately 25% smaller cross-sectional area, and had contractile force reduced by half or more. Markers of the ubiquitin–proteasome pathway were significantly up-regulated in the diaphragm of critically ill patients. Finally, MuRF-1 knockout mice were protected against the development of diaphragm contractile weakness during mechanical ventilation. Conclusions: These findings show that diaphragm muscle fibers of critically ill patients display atrophy and severe contractile weakness, and in the diaphragm of critically ill patients the ubiquitin–proteasome pathway is activated. This study provides rationale for the development of treatment strategies that target the contractility of diaphragm fibers to facilitate weaning. PMID:25760684
A highly sensitive fiber Bragg grating diaphragm pressure transducer
NASA Astrophysics Data System (ADS)
Allwood, Gary; Wild, Graham; Lubansky, Alex; Hinckley, Steven
In this work, a novel diaphragm based pressure transducer with high sensitivity is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of practical implementation and limitations. A flat circular rubber membrane bonded to a cylinder forms the body of the transducer. A fiber Bragg grating bonded to the center of the diaphragm structure enables the fractional change in pressure to be determined by analyzing the change in Bragg wavelength of the reflected spectra. Extensive evaluation of the physical properties and optical characteristics of the transducer has been performed through experimentation, and modeling using small deformation theory. The results show the transducer has a sensitivity of 0.116 nm/kPa, across a range of 15 kPa. Ultra-low cost interrogation of the optical signal was achieved through the use of an optically mismatched Bragg grating acting as an edge filter to convert the spectral change into an intensity change. A numerical model of the intensity based interrogation was implemented in order to validate the experimental results. Utilizing this interrogation technique and housing both the sensing and reference Bragg gratings within the main body of the transducer means it is effectively temperature insensitive and easily connected to electronic systems.
Phrenic and diaphragm function after coronary artery bypass grafting.
Estenne, M; Yernault, J C; De Smet, J M; De Troyer, A
We studied respiratory mechanics and phrenic nerve and diaphragm function in 12 patients on the day before and eight to 13 days after coronary artery bypass grafting. The average vital capacity, functional residual capacity, and total lung capacity decreased by 20.5%, 9.5%, and 14.7% respectively after operation. Eleven patients showed less negative maximum inspiratory mouth pressures at any given lung volume after surgery and the magnitude of the change correlated with the reduction in total lung capacity. In 11 of the 12 patients the conduction times of the right and left phrenic nerves did not change substantially after operation and the ratio of inspiratory electrical activity (Edi) of left and right hemidiaphragms was similar before and after the procedure. One patient, however, showed a considerable increase in left phrenic nerve conduction time and a reduction in the left to right Edi ratio postoperatively. In three patients diaphragm function was also assessed by changes in transdiaphragmatic pressure during supramaximal phrenic nerve stimulation and voluntary increase in inspired volume; in none of the three patients did the transdiaphragmatic pressure swings show any significant change in the postoperative period. These data indicate that phrenic nerve paralysis only occasionally accounts for the postoperative loss of lung volume after coronary artery bypass grafting surgery. The mechanism of these abnormalities therefore remains to be determined. PMID:3875161
Experimental Characterization of Piezoelectric Radial Field Diaphragms for Fluidic Control
NASA Technical Reports Server (NTRS)
Bryant, R. G.; Kavli, S. E.; Thomas, R. A., Jr.; Darji, K. J.; Mossi, K. M.
NASA has recently developed a new piezoelectric actuator, the Radial Field Diaphragm or RFD. This actuator uses a radially-directed electric field to generate concentric out-of-plane (Z-axis) motion that allows this packaged device to be used as a pump or valve diaphragm. In order to efficiently use this new active device, experimental determination of pressure, flow rate, mechanical work, power consumption and overall efficiency needs to be determined by actually building a pump. However, without an optimized pump design, it is difficult to assess the quality of the data, as these results are inherent to the actual pump. Hence, separate experiments must be conducted in order to generate independent results to help guide the design criteria and pump quality. This paper focuses on the experiments used to generate the RFD's operational parameters and then compares these results to the experimentally determined results of several types of ball pumps. Also discussed are how errors are inherently introduced into the experiments, the pump design, experimental hardware and their effects on the overall system efficiency.
Laparoscopic Transperitoneal Repair of Pediatric Diaphragm Eventration Using an Endostapler Device
Lao, Victoria Valinluck; Lao, Oliver B.
Abstract Background Minimally invasive repairs of pediatric diaphragm eventration have been well described via a thoracoscopic approach, oftentimes requiring single-lung ventilation and tube thoracostomy, with the disadvantage of not being able to clearly visualize what lies beneath the diaphragm. We describe a novel pediatric diaphragm eventration repair using a laparoscopic transperitoneal approach and an endostapler device. We also describe our initial experience with this technique. Patients and Methods Four pediatric diaphragmatic eventration patients underwent laparoscopic transperitoneal repair using an endostapler device. Repairs were performed in both male and female patients with right-sided eventrations. We approach the repair in a transperitoneal fashion using inverting sutures at the apex of the diaphragm to create tension toward the pelvis. Subsequently, an endostapler is used to remove the redundant portion of diaphragm, leaving a repaired, taut diaphragm. Results The median age at operation was 10.5 months. The median operative time was 70 minutes. There was no mortality, surgical complications, or recurrence at a median follow-up of 17 months. Conclusions This laparoscopic approach allows for clear visualization of the intraabdominal organs and, at least in our early experience, a very simple, straightforward operation. Additionally, with the use of the endostapler, the redundant, often weakened diaphragm is removed, leaving the native, healthy diaphragm behind, resulting in a reliable and reproducible repair. This repair should be considered as a feasible alternative approach to the more traditional open and thoracoscopic repairs. PMID:23937143
Mitochondrial-targeted antioxidants protect against mechanical ventilation-induced diaphragm weakness
Powers, Scott K.; Hudson, Matthew B.; Nelson, W. Bradley; Talbert, Erin E.; Min, Kisuk; Szeto, Hazel H.; Kavazis, Andreas N.; Smuder, Ashley J.
BACKGROUND Mechanical ventilation (MV) is a life-saving intervention used to provide adequate pulmonary ventilation in patients suffering from respiratory failure. However, prolonged MV is associated with significant diaphragmatic weakness resulting from both myofiber atrophy and contractile dysfunction. Although several signaling pathways contribute to diaphragm weakness during MV, it is established that oxidative stress is required for diaphragmatic weakness to occur. Therefore, identifying the site(s) of MV-induced reactive oxygen species (ROS) production in the diaphragm is important. OBJECTIVE These experiments tested the hypothesis that elevated mitochondrial ROS emission is required for MV-induced oxidative stress, atrophy, and contractile dysfunction in the diaphragm. DESIGN Cause and effect was determined by preventing MV-induced mitochondrial ROS emission in the diaphragm of rats using a novel mitochondrial-targeted antioxidant (SS-31). MEASUREMENTS AND MAIN RESULTS Compared to mechanically ventilated animals treated with saline, animals treated with SS-31 were protected against MV-induced mitochondrial dysfunction, oxidative stress, and protease activation in the diaphragm. Importantly, treatment of animals with the mitochondrial antioxidant also protected the diaphragm against MV-induced myofiber atrophy and contractile dysfunction. CONCLUSIONS These results reveal that prevention of MV-induced increases in diaphragmatic mitochondrial ROS emission protects the diaphragm MV-induced diaphragmatic weakness. This important new finding indicates that mitochondria are a primary source of ROS production in the diaphragm during prolonged MV. These results could lead to the development of a therapeutic intervention to impede MV-induced diaphragmatic weakness. PMID:21460706
Alterations of diaphragm and rib cage morphometry in severe COPD patients by CT analysis.
Salito, C; Luoni, E; Aliverti, A
Although it is known that in patients with COPD acute hyperinflation determines shortening of the inspiratory muscles, its effects on both diaphragm and rib cage morphology are still to be investigated. In this preliminary study the relationships between hyperinflation, emphysema, diaphragm and rib cage geometry were studied in 5 severe COPD patients and 5 healthy subjects. An automatic software was developed to obtain the 3-D reconstruction of diaphragm and rib cage from CT scans taken at total lung capacity (TLC) and residual volume (RV). Dome surface area (Ado), radius of curvature, length (Ld) and position (referred to xiphoid level) of the diaphragm and antero-posterior (A-P) and transverse (T) diameters of rib cage were calculated at both volumes. Ado and Ld were similar in COPD and controls when compared at similar absolute lung volumes. Radius of curvature was significantly higher in COPD than in controls only at TLC. In COPD, the range of diaphragm position was invariantly below the xiphoid level, while in controls the top of diaphragm dome was always above it. Rib cage diameters were not different at TLC. A-P diameter was greater in COPD than in controls at RV, while T diameters were similar. In conclusion, in severe COPD diaphragm and rib cage geometry is altered at RV. The lower position of diaphragm is associated to smaller A-P but not transversal rib cage diameters, such that rib cage adopts a more circular shape. PMID:26737755
Electro-Active Device Using Radial Electric Field Piezo-Diaphragm for Control of Fluid Movement
NASA Technical Reports Server (NTRS)
Bryant, Robert G. (Inventor); Working, Dennis C. (Inventor)
A fluid-control electro-active device includes a piezo-diaphragm made from a ferroelectric material sandwiched by first and second electrode patterns configured to introduce an electric field into the ferroelectric material when voltage is applied thereto. The electric field originates at a region of the ferroelectric material between the first and second electrode patterns, and extends radially outward from this region of the ferroelectric material and substantially parallel to the plane of the ferroelectric material. The piezo-diaphragm deflects symmetrically about this region in a direction substantially perpendicular to the electric field. An annular region coupled to and extending radially outward from the piezo-diaphragm perimetrically borders the piezo-diaphragm, A housing is connected to the region and at least one fluid flow path with piezo-diaphragm disposed therein.
The diaphragms of fenestrated endothelia – gatekeepers of vascular permeability and blood composition
Stan, Radu V.; Tse, Dan; Deharvengt, Sophie J.; Smits, Nicole C.; Xu, Yan; Luciano, Marcus R.; McGarry, Caitlin L.; Buitendijk, Maarten; Nemani, Krishnamurthy V.; Elgueta, Raul; Kobayashi, Takashi; Shipman, Samantha L.; Moodie, Karen L.; Daghlian, Charles P.; Ernst, Patricia A.; Lee, Hong-Kee; Suriawinata, Arief A.; Schned, Alan R.; Longnecker, Daniel S.; Fiering, Steven N.; Noelle, Randolph J.; Gimi, Barjor; Shworak, Nicholas W.; Carrière, Catherine
SUMMARY Fenestral and stomatal diaphragms are endothelial subcellular structures of unknown function that form on organelles implicated in vascular permeability: fenestrae, transendothelial channels and caveolae. PV1 protein is required for diaphragm formation in vitro. Here, we report that deletion of the PV1-encoding Plvap gene in mice results in the absence of diaphragms and decreased survival. Loss of diaphragms did not affect the fenestrae and transendothelial channels formation but disrupted the barrier function of fenestrated capillaries causing a major leak of plasma proteins. This disruption results in early death of animals due to severe non-inflammatory protein loosing enteropathy. Deletion of PV1 in endothelium, but not the hematopoietic compartment, recapitulates the phenotype of global PV1 deletion, whereas endothelial reconstitution of PV1 rescues the phenotype. Taken together, these data provide genetic evidence for the critical role of the diaphragms in fenestrated capillaries in the maintenance of blood composition. PMID:23237953
Functional and morphological assessment of diaphragm innervation by phrenic motor neurons.
Martin, Melanie; Li, Ke; Wright, Megan C; Lepore, Angelo C
This protocol specifically focuses on tools for assessing phrenic motor neuron (PhMN) innervation of the diaphragm at both the electrophysiological and morphological levels. Compound muscle action potential (CMAP) recording following phrenic nerve stimulation can be used to quantitatively assess functional diaphragm innervation by PhMNs of the cervical spinal cord in vivo in anesthetized rats and mice. Because CMAPs represent simultaneous recording of all myofibers of the whole hemi-diaphragm, it is useful to also examine the phenotypes of individual motor axons and myofibers at the diaphragm NMJ in order to track disease- and therapy-relevant morphological changes such as partial and complete denervation, regenerative sprouting and reinnervation. This can be accomplished via whole-mount immunohistochemistry (IHC) of the diaphragm, followed by detailed morphological assessment of individual NMJs throughout the muscle. Combining CMAPs and NMJ analysis provides a powerful approach for quantitatively studying diaphragmatic innervation in rodent models of CNS and PNS disease. PMID:26066371
Design and characterisation of micro-diaphragm for low power drug delivery applications
NASA Astrophysics Data System (ADS)
Dissanayake, Don W.; Al-Sarawi, Said F.; Lu, Tien-Fu; Abbott, Derek
Micro-fabricated diaphragms can be used to provide pumping action in microvalve and microfluidic applications. In this paper, a design for a micro-diaphragm that features low power and small area is presented. The diaphragm is actuated using a Surface Acoustic Wave (SAW) device that is interrogated from an RF signal to provide secure actuation operation. The micropump is targeted for in vivo nano-scale drug delivery and similar applications. For low power micropump operation, it is important to design the diaphragm with a higher flexibility while maintaining the stability. Analysis is carried out using ANSYS simulation tools with different design methods and materials. Results achieved from analytical and Finite Element Modeling (FEM) methods are compared and discussed to decide on optimal dimensions for the diaphragm.
The importance of discreet use of the diaphragm to Zimbabwean women and their partners.
Kang, Mi-Suk; Buck, Jessica; Padian, Nancy; Posner, Sam F; Khumalo-Sakutukwa, Gertrude; van der Straten, Ariane
We conducted a 6-month acceptability study of diaphragms as a potential HIV/STI prevention method among Zimbabwean women. We examined partner involvement in diaphragm use, and importance of discreet use (use without partner awareness). Of the 181 women who completed the study, 45% said discreet use was "very or extremely important" and in multivariate logistic regression, women were more likely to value discretion if their partners: had other partners; drank alcohol; or were believed to prefer condoms to diaphragms. Qualitative data confirmed these findings. Both women and their partners reported that diaphragms can be used discreetly and saw this as advantageous, for both sexual pleasure and female control. However, many were concerned that use without partner approval could lead to marital problems. Discreet use should be considered in development of barrier methods and in diaphragm promotion, if proven effective against HIV/STI. PMID:17160486
Introducing diaphragms into the mix: what happens to male condom use patterns?
Posner, Samuel F; van der Straten, Ariane; Kang, Mi-Suk; Padian, Nancy; Chipato, Tsungai
The objective of this analysis was to assess the effect of introducing the diaphragm on condom use patterns. Participants included one hundred eighty-nine women attending family planning clinics in Harare, Zimbabwe who reported less than 100% condom use. The proportion of acts where at least one method was used significantly increased over using follow-up; male condom use remained stable. A diaphragm was used with 50% to 54% of acts; male condoms were also used about 50% of the time. The proportion of acts where a female condom was used decreased. Women who used both male and female condoms were more likely to use diaphragms than those who reported not using female condoms. Introducing the diaphragm increased the overall proportion of protected acts. The proportion of acts where a male condom was used did not change. Female condoms use declined because concurrent use with the diaphragm is not possible. PMID:16235134
Use of diaphragm transducers in the measurement of pressures on soft materials.
Jhoun, J H; Childress, D S
Diaphragm pressure transducers are designed to measure pressures in fluids, but have also been applied to measuring pressures on soft materials, such as at the interface between the residual limb of a lower-limb amputee and the supporting surface defined by the prosthetic socket. The reliability and accuracy of Kulite XTM-190 transducer as a pressure monitor on soft materials, such as silicone and Pelite was evaluated in three physical model set-ups. The evaluations included the uniform loading of solid disks of silicone and Pelite, the application of air pressure to the core of a contained thick-walled cylinder made of silicone, and the dynamic indentation of a contained solid silicone cylinder. Sensor measurements in all situations were similar to analytical, iterative or finite element solutions when certain conditions were met. These conditions include: (i) lubricating the interface between the soft material and the supporting structure; (ii) calibrating the transducers under surface and material conditions used during measurements; and (iii) using compatible soft materials (e.g. silicone but not Pelite). PMID:10367471
Differential Expression of Lipid and Carbohydrate Metabolism Genes in Upper Airway versus Diaphragm Muscle
van Lunteren, Erik; Spiegler, Sarah; Moyer, Michelle
Study Objectives: Contractile properties of upper airway muscles influence upper airway patency, an issue of particular importance for subjects with obstructive sleep apnea. Expression of genes related to cellular energetics is, in turn, critical for the maintenance of contractile integrity over time during repetitive activation. We tested the hypothesis that sternohyoid has lower expression of genes related to lipid and carbohydrate energetic pathways than the diaphragm. Methods: Sternohyoid and diaphragm from normal adult rats were examined with gene expression arrays. Analysis focused on genes belonging to Gene Ontology (GO) groups carbohydrate metabolism and lipid metabolism. Results: There were 433 genes with at least ± 2-fold significant differential expression between sternohyoid and diaphragm, of which 192 had sternohyoid > diaphragm and 241 had diaphragm > sternohyoid expression. Among genes with higher sternohyoid expression, there was over-representation of the GO group carbohydrate metabolism (P = 0.0053, n = 13 genes, range of differential expression 2.1- to 6.2-fold) but not lipid metabolism (P = 0.44). Conversely, among genes with higher diaphragm expression, there was over-representation of the GO group lipid metabolism (P = 0.0000065, n = 32 genes, range of differential expression 2.0- to 37.9-fold) but not carbohydrate metabolism (P = 0.23). Nineteen genes with diaphragm > sternohyoid expression were related to fatty acid metabolism (P = 0.000000058), in particular fatty acid β oxidation and biosynthesis in the mitochondria. Conclusions: Sternohyoid has much lower gene expression than diaphragm for mitochondrial enzymes that participate in fatty acid oxidation and biosynthesis. This likely contributes to the lower fatigue resistance of pharyngeal upper airway muscles compared with the diaphragm. Citation: van Lunteren E; Spiegler S; Moyer M. Differential expression of lipid and carbohydrate metabolism genes in upper airway versus diaphragm
Fully automatic algorithm for segmenting full human diaphragm in non-contrast CT Images
NASA Astrophysics Data System (ADS)
Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas
The diaphragm is a sheet of muscle which separates the thorax from the abdomen and it acts as the most important muscle of the respiratory system. As such, an accurate segmentation of the diaphragm, not only provides key information for functional analysis of the respiratory system, but also can be used for locating other abdominal organs such as the liver. However, diaphragm segmentation is extremely challenging in non-contrast CT images due to the diaphragm's similar appearance to other abdominal organs. In this paper, we present a fully automatic algorithm for diaphragm segmentation in non-contrast CT images. The method is mainly based on a priori knowledge about the human diaphragm anatomy. The diaphragm domes are in contact with the lungs and the heart while its circumference runs along the lumbar vertebrae of the spine as well as the inferior border of the ribs and sternum. As such, the diaphragm can be delineated by segmentation of these organs followed by connecting relevant parts of their outline properly. More specifically, the bottom surface of the lungs and heart, the spine borders and the ribs are delineated, leading to a set of scattered points which represent the diaphragm's geometry. Next, a B-spline filter is used to find the smoothest surface which pass through these points. This algorithm was tested on a noncontrast CT image of a lung cancer patient. The results indicate that there is an average Hausdorff distance of 2.96 mm between the automatic and manually segmented diaphragms which implies a favourable accuracy.
Mark J. Russell; Robert E. Spears; Ryan G. Kobbe
The structure of a building undergoing a seismic reevaluation at the Idaho National Laboratory includes a number of steel plate walls and a roof liner which will act as shear diaphragms during an earthquake. Since the facility was designed and built long before such criteria were formulated, it is not surprising that these walls are not configured to meet all of the recently formulated requirements for such structures. To take advantage of this unusual structural feature, nonlinear analysis was used to ensure accurate modeling of the plate walls in a linear elastic seismic analysis of the full superstructure. The modeling was also used to establish the capacity of the plate.
Etude de champ proche d'un laser diaphragme
Kellou, A.; Stephan, G.
A circular aperture is generally used inside a metrologic gas laser to suppress transverse modes. The resonant field inside the laser or the near field observable at the output display longitudinal or transverse oscillations due to diffraction. These fields are different from the Gaussian modes usually obtained from nondiaphragmed cavities. This article studies the near field of a diaphragmed laser in both experimental and theoretical aspects. For this purpose we use a field expansion on the basis of geometrical Laguerre Gauss modes and we calculate the field diffracted by an aperture, inside a resonant cavity. This allows calculation of the measurable field at the laser output. Numerical application and corresponding experiments are done with a single frequency laser working on the 3.39-..mu..m Ne line. Excellent agreement is obtained between experimental and theoretical curves.
DC diaphragm discharge in water solutions of selected organic acids
NASA Astrophysics Data System (ADS)
Vyhnankova, Edita J.; Hammer, Malte U.; Reuter, Stephan; Krcma, Frantisek
Effect of four simple organic acids water solution on a DC diaphragm discharge was studied. Efficiency of the discharge was quantified by the hydrogen peroxide production determined by UV-VIS spectrometry of a H2O2 complex formed with specific titanium reagent. Automatic titration was used to study the pH behaviour after the plasma treatment. Optical emission spectroscopy overview spectra were recorded and detailed spectra of OH band and Hβ line were used to calculate the rotational temperature and comparison of the line profile (reflecting electron concentration) in the acid solutions. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark
Piconewton force measurement using a nanometric photonic crystal diaphragm.
Jo, Wonuk; Digonnet, Michel J F
A compact force fiber sensor capable of measuring forces at the piconewton level is reported. It consists of a miniature Fabry-Perot cavity fabricated at the tip a single-mode fiber, in which the external reflector is a compliant photonic-crystal diaphragm that deflects when subjected to a force. In the laboratory environment, this sensor was able to detect a force of only ∼4 pN generated by the radiation pressure of a laser beam. Its measured minimum detectable force (MDF) at 3 kHz was as weak as 1.3 pN/√Hz. In a quiet environment, the measured noise was ∼16 times lower, and the MDF predicted to be ∼76 fN/√Hz. PMID:25078221
Diaphragm cell determination of the interdiffusion coefficient for succinonitrile + water
NASA Astrophysics Data System (ADS)
Cain, J. B.; Clunie, J. C.; Baird, J. K.
Using diaphragm cells, we have measured the interdiffusion coefficient for succinonitrile+water in the one-phase liquid region at a series of temperatures ranging form 25 to 60°C and compositions ranging from 34.5 to 96 mol% water. The diffusion coefficient was found to be a function of both temperature and concentration, varying from 1.66×10-6 to 16.6×10-6 cm2·s-1. Critical slowing down of diffusion was readily detected at 60°C (critical temperature, 56.17°C) over a broad range of composition on either side of the critical composition (82.7 mol% water).
Cerium oxide nanoparticle treatment ameliorates peritonitis-induced diaphragm dysfunction
Asano, Shinichi; Arvapalli, Ravikumar; Manne, Nandini DPK; Maheshwari, Mani; Ma, Bing; Rice, Kevin M; Selvaraj, Vellaisamy; Blough, Eric R
The severe inflammation observed during sepsis is thought to cause diaphragm dysfunction, which is associated with poor patient prognosis. Cerium oxide (CeO2) nanoparticles have been posited to exhibit anti-inflammatory and antioxidative activities suggesting that these particles may be of potential use for the treatment of inflammatory disorders. To investigate this possibility, Sprague Dawley rats were randomly assigned to the following groups: sham control, CeO2 nanoparticle treatment only (0.5 mg/kg iv), sepsis, and sepsis+CeO2 nanoparticles. Sepsis was induced by the introduction of cecal material (600 mg/kg) directly into the peritoneal cavity. Nanoparticle treatment decreased sepsis-associated impairments in diaphragmatic contractile (Po) function (sham: 25.6±1.6 N/cm2 vs CeO2: 23.4±0.8 N/cm2 vs Sep: 15.9±1.0 N/cm2 vs Sep+CeO2: 20.0±1.0 N/cm2, P<0.05). These improvements in diaphragm contractile function were accompanied by a normalization of protein translation signaling (Akt, FOXO-1, and 4EBP1), diminished proteolysis (caspase 8 and ubiquitin levels), and decreased inflammatory signaling (Stat3 and iNOS). Histological analysis suggested that nanoparticle treatment was associated with diminished sarcolemma damage and diminished inflammatory cell infiltration. These data indicate CeO2 nanoparticles may improve diaphragmatic function in the septic laboratory rat. PMID:26491293
Diaphragm breathing movement measurement using ultrasound and radiographic imaging: a concurrent validity.
Noh, Dong K; Lee, Jae J; You, Joshua H
Recent ultrasound imaging evidence asserts that the diaphragm is an important multifunctional muscle to control breathing as well as stabilize the core and posture in humans. However, the validity and accuracy of ultrasound for the measurement of dynamic diaphragm movements during breathing and functional core activities have not been determined. The specific aim of this study was to validate the accuracy of ultrasound imaging measurements of diaphragm movements by concurrently comparing these measurements to the gold standard of radiographic imaging measurements. A total of 14 asymptomatic adults (9 males, 5 females; mean age =28.4 ± 3.0 years) were recruited to participate in the study. Ultrasound and radiographic images were used concurrently to determine diaphragm movement (inspiration, expiration, and excursion) during tidal breathing. Pearson correlation analysis showed strong correlations, ranging from r=0.78 to r=0.83, between ultrasound and radiographic imaging measurements of the diaphragm during inhalation, exhalation, and excursion. These findings suggest that ultrasound imaging measurement is useful to accurately evaluate diaphragm movements during tidal breathing. Clinically, ultrasound imaging measurements can be used to diagnose and treat diaphragm movement impairments in individuals with neuromuscular disorders including spinal cord injuries, stroke, and multiple sclerosis. PMID:24211983
Finite element analysis of AlGaN/GaN micro-diaphragms with diamond coating
NASA Astrophysics Data System (ADS)
Dzuba, J.; Vanko, G.; Vojs, M.; Rýger, I.; Ižák, T.; Jirásek, V.; Kutiš, V.; Lalinský, T.
In this work, we present a pressure sensor based on diamond coated AlGaN/GaN diaphragm with integrated high electron mobility transistor (HEMT). The influence of the diamond film thickness (in the range of 1 μm to 50 μm) on the properties of the AlGaN/GaN diaphragm is studied by finite element simulation method (FEM). The effect of thermal buckling as well as the induced piezoelectric charge of HEMTs as a function of pressure and temperature is investigated. It was found out that diamond coated sensor better prevents the effect known as thermal buckling of the diaphragm at elevated temperature. Thermal buckling of diaphragms with 1, 5, 10 μm diamond coating occurs at temperature 40, 73 and 142 °C, respectively. Compared with original GaN diaphragm, diamond expanded the operational temperature range of the pressure sensor. Moreover, compared with the operational range of pressure sensor based on pure GaN diaphragm (up to 30 kPa), diamond coated modified MEMS sensors withstand relatively higher pressures (2.2 MPa). The maximum load on the diaphragm increased two times by adding only 1 μm of diamond coating.
Gorbunkov, S D; Varlamov, V V; Gichkin, A Yu; Perley, V E; Chernyi, S M; Romanikhin, A I; Syrovnev, V A; Agishev, A S; Akopov, A L
The article showed the results of ultrasonic assessment of topographic and functional diaphragm indices in patients with severe diffuse emphysema. They passed the selection for lung volume reduction surgery. The comparison of diaphragm indices was presented in patients with diffuse emphysema and control group of healthy volunteers. Dynamics of diaphragm condition was studied after surgical treatment. There wasn't noted any statistical difference of diaphragm topographic indices as compared with the control group. There wasn't shown a correlation between respiratory function indices and functional diaphragm indices, but it was noted a positive tendency in characteristics during quiet breathing. PMID:26983252
Redox Remodeling Is Pivotal in Murine Diaphragm Muscle Adaptation to Chronic Sustained Hypoxia.
Lewis, Philip; Sheehan, David; Soares, Renata; Coelho, Ana Varela; O'Halloran, Ken D
Mechanisms underpinning chronic sustained hypoxia (CH)-induced structural and functional adaptations in respiratory muscles are unclear despite the clinical relevance to respiratory diseases. The objectives of the present study were to thoroughly assess the putative role of CH-induced redox remodeling in murine diaphragm muscle over time and the subsequent effects on metabolic enzyme activities, catabolic signaling and catabolic processes, and diaphragm muscle contractile function. C57Bl6/J mice were exposed to normoxia or normobaric CH (fraction of inspired oxygen = 0.1) for 1, 3, or 6 weeks. A second cohort was exposed to CH for 6 weeks with and without antioxidant supplementation (tempol or N-acetyl cysteine). After CH exposure, we performed two-dimensional redox proteomics with mass spectrometry, enzyme activity assays, and cell-signaling assays on diaphragm homogenates. We also assessed diaphragm isotonic contractile and endurance properties ex vivo. Global protein redox changes in the diaphragm after CH are indicative of oxidation. Remodeling of proteins key to contractile, metabolic, and homeostatic functions was observed. Several oxidative and glycolytic enzyme activities were decreased by CH. Redox-sensitive chymotrypsin-like proteasome activity of the diaphragm was increased. CH decreased phospho-forkhead box O3a (FOXO3a) and phospho-mammalian target of rapamycin content. Hypoxia-inducible factor-1α and phospho-p38 mitogen-activated protein kinase content was increased in CH diaphragm, and this was attenuated by antioxidant treatment. CH exposure decreased force- and power-generating capacity of the diaphragm, and this was prevented by antioxidant supplementation with N-acetyl cysteine but not tempol. Redox remodeling is pivotal for diaphragm adaptation to CH, affecting metabolic activity, atrophy signaling, and functional performance. Antioxidant supplementation may be useful as an adjunctive therapy in respiratory-related diseases characterized by
Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI
Mogalle, Katja; Perez-Rovira, Adria; Ciet, Pierluigi; Wens, Stephan C. A.; van Doorn, Pieter A.; Tiddens, Harm A. W. M.; van der Ploeg, Ans T.; de Bruijne, Marleen
Background Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness. Methods The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle. Results Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls. Conclusion Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response. PMID:27391236
Acceptability and feasibility of continuous diaphragm use among sex workers in Madagascar
Behets, F; Turner, A; Van Damme, K; Rabenja, N; Ravelomanana, N; Zeller, K; Rasolofomanana, J
Objectives: The diaphragm, a woman controlled, reusable contraceptive device, might prevent some sexually transmitted infections (STIs). We assessed the acceptability and feasibility of use of silicone Wide-Seal Arcing Diaphragms (Milex Products, Chicago, IL, USA) by sex workers in Madagascar. Methods: Over 8 weeks, we evaluated method acceptability by examining patterns of and problems with women's diaphragm use. We also evaluated several measures of study feasibility, including recruitment and follow up methods. Results: 91 women from three cities (Antananarivo, Tamatave, and Mahajanga) participated, and 87 (96%) completed follow up. At enrolment, participants reported a median of six sex acts with five clients in the previous week. During the follow up period, participants reported a median of three sex acts with three clients during the previous 2 days, and self reported continuous diaphragm use during the previous day increased from 87% to 93%. Seven women became pregnant (incidence 53 pregnancies per 100 woman years). Self reported use of male condoms and diaphragms was fairly constant over the study period: women reported condom use in 61% to 70% of acts and diaphragms in 95% to 97% of acts. The number of participants reporting diaphragm problems decreased from 15 (16%) at the first visit to six (7%) at the final visit. 20 women (22%) needed replacement devices during follow up because their original diaphragms were lost, were the wrong size, or became seriously damaged. Conclusions: Given the high use and steady decrease in reported problems during the study, we believe diaphragms are acceptable and feasible in this resource poor, low education sex worker population. PMID:16326849
Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm
Moore, James J.; Lerche, Andrew H.; Moreland, Brian S.
An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing though the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.
High-sensitivity Fabry-Perot interferometric pressure sensor based on a nanothick silver diaphragm.
Xu, Feng; Ren, Dongxu; Shi, Xiaolong; Li, Can; Lu, Weiwei; Lu, Lu; Lu, Liang; Yu, Benli
We present a fiber-optic extrinsic Fabry-Perot interferometer pressure sensor based on a nanothick silver diaphragm. The sensing diaphragm, with a thickness measured in a few hundreds of nanometers, is fabricated by the electroless plating method, which provides a simple fabrication process involving a high-quality diaphragm at a low cost. The sensor exhibits a relatively linear response within the pressure variation range of 0-50 kPa, with a high pressure sensitivity of 70.5 nm/kPa. This sensor is expected to have potential applications in the field of highly sensitive pressure sensors. PMID:22854444
Development, Fabrication, and Characterization of Hydrogel Based Piezoresistive Pressure Sensors with Perforated Diaphragms
Orthner, M.P.; Buetefisch, Sebastian; Magda, J.; Rieth, L.W.; Solzbacher, F.
Hydrogels have been demonstrated to swell in response to a number of external stimuli including pH, CO2, glucose, and ionic strength making them useful for detection of metabolic analytes. To measure hydrogel swelling pressure, we have fabricated and tested novel perforated diaphragm piezoresistive pressure sensor arrays that couple the pressure sensing diaphragm with a perforated semi-permeable membrane. The 2×2 arrays measure approximately 3 × 5 mm2 and consist of four square sensing diaphragms with widths of 1.0, 1.25, and 1.5 mm used to measure full scale pressures of 50, 25, and 5 kPa, respectively. An optimized geometry of micro pores was etched in silicon diaphragm to allow analyte diffusion into the sensor cavity where the hydrogel material is located. The 14-step front side wafer process was carried out by a commercial foundry service (MSF, Frankfurt (Oder), Germany) and diaphragm pores were created using combination of potassium hydroxide (KOH) etching and deep reactive ion etching (DRIE). Sensor characterization was performed (without the use of hydrogels) using a custom bulge testing apparatus that simultaneously measured deflection, pressure, and electrical output. Test results are used to quantify the sensor sensitivity and demonstrate proof-of-concept. Simulations showed that the sensitivity was slightly improved for the perforated diaphragm designs while empirical electrical characterization showed that the perforated diaphragm sensors were slightly less sensitive than solid diaphragm sensors. This discrepancy is believed to be due to the influence of compressive stress found within passivation layers and poor etching uniformity. The new perforated diaphragm sensors were fully functional with sensitivities ranging from 23 to 252 μV/V-kPa (FSO= 5 to 80mV), and show a higher nonlinearity at elevated pressures than identical sensors with solid diaphragms. Sensors (1.5×1.5 mm2) with perforated diaphragms (pores=40 μm) have a nonlinearity of
An experimental evaluation of metallic diaphragms for positive fuel expulsion in the atmosphere explorer hydrazine propulsion subsystem
NASA Technical Reports Server (NTRS)
Woodruff, W. L.
Four Arde conospheroid metallic diaphragms were tested to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Explorer spacecraft. The diaphragms will be used for positive propellant expulsion and spacecraft center of mass control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 7 N/sq cm during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft center of mass control, the diaphragm must not be reversed prior to flight.
Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition.
Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang
In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing. PMID:26771617
Transfixing cardiac injury with perforations in stomach, diaphragm and lung: unusual scenario in penetrating trauma
Karigyo, Carlos Junior Toshiyuki; Fan, Otavio Goulart; Yoshida, Marcelo Miyazaki; Menescal, Roberto Jonathas; Tarasiewich, Marcos Jose
A 23-year-old man suffered a penetrating injury caused by a metallic fragment thrown from a grass-cutting tool, resulting in perforating injuries in the stomach, diaphragm, heart, and lungs. PMID:24896170
Design of Diaphragm and Coil for Stable Performance of an Eddy Current Type Pressure Sensor
Lee, Hyo Ryeol; Lee, Gil Seung; Kim, Hwa Young; Ahn, Jung Hwan
The aim of this work was to develop an eddy current type pressure sensor and investigate its fundamental characteristics affected by the mechanical and electrical design parameters of sensor. The sensor has two key components, i.e., diaphragm and coil. On the condition that the outer diameter of sensor is 10 mm, two key parts should be designed so as to keep a good linearity and sensitivity. Experiments showed that aluminum is the best target material for eddy current detection. A round-grooved diaphragm is suggested in order to measure more precisely its deflection caused by applied pressures. The design parameters of a round-grooved diaphragm can be selected depending on the measuring requirements. A developed pressure sensor with diaphragm of t = 0.2 mm and w = 1.05 mm was verified to measure pressure up to 10 MPa with very good linearity and errors of less than 0.16%. PMID:27376306
Anatomic connections of the diaphragm: influence of respiration on the body system
Bordoni, Bruno; Zanier, Emiliano
The article explains the scientific reasons for the diaphragm muscle being an important crossroads for information involving the entire body. The diaphragm muscle extends from the trigeminal system to the pelvic floor, passing from the thoracic diaphragm to the floor of the mouth. Like many structures in the human body, the diaphragm muscle has more than one function, and has links throughout the body, and provides the network necessary for breathing. To assess and treat this muscle effectively, it is necessary to be aware of its anatomic, fascial, and neurologic complexity in the control of breathing. The patient is never a symptom localized, but a system that adapts to a corporeal dysfunction. PMID:23940419
Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition
Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang
In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing. PMID:26771617
Design of Diaphragm and Coil for Stable Performance of an Eddy Current Type Pressure Sensor.
Lee, Hyo Ryeol; Lee, Gil Seung; Kim, Hwa Young; Ahn, Jung Hwan
The aim of this work was to develop an eddy current type pressure sensor and investigate its fundamental characteristics affected by the mechanical and electrical design parameters of sensor. The sensor has two key components, i.e., diaphragm and coil. On the condition that the outer diameter of sensor is 10 mm, two key parts should be designed so as to keep a good linearity and sensitivity. Experiments showed that aluminum is the best target material for eddy current detection. A round-grooved diaphragm is suggested in order to measure more precisely its deflection caused by applied pressures. The design parameters of a round-grooved diaphragm can be selected depending on the measuring requirements. A developed pressure sensor with diaphragm of t = 0.2 mm and w = 1.05 mm was verified to measure pressure up to 10 MPa with very good linearity and errors of less than 0.16%. PMID:27376306
Design and fabrication of dielectric diaphragm pressure sensors for applications to shock wave measurement in air
NASA Astrophysics Data System (ADS)
Parkes, W.; Djakov, V.; Barton, J. S.; Watson, S.; MacPherson, W. N.; Stevenson, J. T. M.; Dunare, C. C.
Optical fibre pressure sensors have potential performance advantages over electrical sensors in measuring rapid transients such as shock waves from explosive blasts. We report the development of micromachined optical fibre Fabry-Pérot pressure sensors using a silicon dioxide or nitride diaphragm and detail the fabrication stages of the sensor body and diaphragm. The planar technology used is based on silicon deep etching and direct fusion bonding of silicon wafers. Test results for both types of diaphragm are presented. Sensors with rise times better than 3 µs, range 0.1 to 1 MPa and resolution ~500 Pa have been demonstrated in explosives trials. Despite the difference in the sign of stress for the two diaphragm types, both demonstrated excellent high-speed response to explosively generated air shocks.
Embossed Teflon AF Laminate Membrane Microfluidic Diaphragm Valves
NASA Technical Reports Server (NTRS)
Willis, Peter; Hunt, Brian; White,Victor; Grunthaner, Frank
A microfluidic system has been designed to survive spaceflight and to function autonomously on the Martian surface. It manipulates microscopic quantities of liquid water and performs chemical analyses on these samples to assay for the presence of molecules associated with past or present living processes. This technology lies at the core of the Urey Instrument, which is scheduled for inclusion on the Pasteur Payload of the ESA ExoMars rover mission in 2013. Fabrication processes have been developed to make the microfabricated Teflon-AF microfluidic diaphragm pumps capable of surviving extreme temperature excursions before and after exposure to liquid water. Two glass wafers are etched with features and a continuous Teflon membrane is sandwiched between them (see figure). Single valves are constructed using this geometry. The microfabricated devices are then post processed by heating the assembled device while applying pneumatic pressure to force the Teflon diaphragm against the valve seat while it is softened. After cooling the device, the embossed membrane retains this new shape. This solves previous problems with bubble introduction into the fluid flow where deformations of the membrane at the valve seat occurred during device bonding at elevated temperatures (100-150 C). The use of laminated membranes containing commercial Teflon AF 2400 sheet sandwiched between spun Teflon AF 1600 layers performed best, and were less gas permeable than Teflon AF 1600 membranes on their own. Spinning Teflon AF 1600 solution (6 percent in FLOURINERT(Registered TradeMark) FC40 solvent, 3M Company) at 500 rpm for 1.5 seconds, followed by 1,000 rpm for 3 seconds onto Borofloat glass wafers, results in a 10-micron-thick film of extremely smooth Teflon AF. This spinning process is repeated several times on flat, blank, glass wafers in order to gradually build a thick, smooth membrane. After running this process at least five times, the wafer and Teflon coating are heated under vacuum
Diaphragm contractile dysfunction causes by off-target low-dose irradiation
Hsieh, Chen-Hsi; Lin, Yun-Cheng; Chen, Yu-Jen; Wu, Huey-Dong; Wang, Li-Ying
Background: Diaphragm is a primary inspiratory muscle and often receives off-target dose in patients with thoracic radiotherapy, and whether acute effect of low dose irradiation would cause contractile dysfunction of the diaphragm remains unclear. We use a rat model to investigate the effect of low-dose irradiation on diaphragm contractile function in the current study. Methods: The radiation dose distributions in patients with esophageal cancer receiving radiotherapy were calculated to determine the dose received by the off-target diaphragm area. Rats were randomly assigned to an irradiated or a non-irradiated control group (n = 10 per group). A single-fraction of 5 Gy radiation was then delivered to the diaphragms of Sprague-Dawley rats in the irradiated group. The control group received sham irradiation (0 Gy). Rats were sacrificed 24 hours after the irradiation procedures and diaphragms were removed en bloc for contractile function assessment, oxidative injury and DNA damage analysis. Oxidative injury was determined by analyzing concentration of protein carbonyls and DNA damage was determined by analyzing retention of γH2AX foci in nuclei of diaphragmatic tissue. Results: At 24 hours after delivery of a single dose of 5 Gy radiation, specific twitch (p = 0.03) and tetanus tension (p = 0.02) were significantly lower in the irradiated group than in the control group. The relative force-frequency curves showed a significant downward shift in the irradiated group. Protein carbonyl level (p < 0.01) and percentage of γH2AX-positive diaphragm muscle cells were significantly higher in the irradiated group than in the control group 24 hours after irradiation (58% vs. 30%, p = 0.01). Conclusions: Off-target low dose irradiation could induce acute contractile dysfunction of the diaphragm which was related to radiation-induced direct DNA and indirect oxidative damage. PMID:27186277
A new scenario of the evolutionary derivation of the mammalian diaphragm from shoulder muscles
Hirasawa, Tatsuya; Kuratani, Shigeru
The evolutionary origin of the diaphragm remains unclear, due to the lack of a comparable structure in other extant taxa. However, recent researches into the developmental mechanism of this structure have yielded new insights into its origin. Here we summarize current understanding regarding the development of the diaphragm, and present a possible scenario for the evolutionary acquisition of this uniquely mammalian structure. Recent developmental analyses indicate that the diaphragm and forelimb muscles are derived from a shared cell population during embryonic development. Therefore, the embryonic positions of forelimb muscle progenitors, which correspond to the position of the brachial plexus, likely played an important role in the evolution of the diaphragm. We surveyed the literature to reexamine the position of the brachial plexus among living amniotes and confirmed that the cervico-thoracic transition in ribs reflects the brachial plexus position. Using this osteological correlate, we concluded that the anterior borders of the brachial plexuses in the stem synapsids were positioned at the level of the fourth spinal nerve, suggesting that the forelimb buds were laid in close proximity of the infrahyoid muscles. The topology of the phrenic and suprascapular nerves of mammals is similar to that of subscapular and supracoracoid nerves, respectively, of the other amniotes, suggesting that the diaphragm evolved from a muscle positioned medial to the pectoral girdle (cf. subscapular muscle). We hypothesize that the diaphragm was acquired in two steps: first, forelimb muscle cells were incorporated into tissues to form a primitive diaphragm in the stem synapsid grade, and second, the diaphragm in cynodonts became entrapped in the region controlled by pulmonary development. PMID:23448284
Developmental variation of the diaphragm and liver in Fischer 344 rats.
Lu, C C; Mull, R L; Lochry, E A; Christian, M S
The nature and frequency of a developmental variation of the diaphragm and liver in Fischer 344 rats are described. Totals of 20, 98 and 55 (25 for caesarean-sectioning and 30 for natural delivery) mated female rats were used for Experiments 1, 2, and 3, respectively. Each rat was intubated (gavage) with either an aqueous suspension of 0.2% METHOCEL, 0.25% methyl cellulose, or distilled water as a single daily dose from days 6 through 15 (inclusive) of gestation. On the 20th day of gestation, a caesarean-section was performed, and the uterine contents of each rat were examined. A gross necropsy was performed on the pups of 30 mated female rats on day 21 postpartum. The visceral examinations conducted on these fetuses and pups included an evaluation of a developmental variation in the diaphragm and liver. The variation consisted of a thin fibrous central tendon of the diaphragm with an area of liver (0.5-3 mm diameter) that protruded within the thin central tendon of the diaphragm. The incidence (mean % of fetuses affected per litter) of the diaphragm/liver developmental variation was 9% and 11% for METHOCEL- and water-treated groups, respectively. A thin central tendon was present in the diaphragm of all fetuses of methyl cellulose-treated dams; these fetuses did not have a raised area of the liver present within the diaphragm's central tendon. However, in a few weaned pups of the Fischer 344 rats in this study, liver protruded within the central tendon of the diaphragm.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3400072
Measurement of thermal expansion coefficient of graphene diaphragm using optical fiber Fabry–Perot interference
NASA Astrophysics Data System (ADS)
Li, Cheng; Liu, Qianwen; Peng, Xiaobin; Fan, Shangchun
Application of the Fabry–Perot (FP) interference method for determining the coefficient of thermal expansion (CTE) of a graphene diaphragm is investigated in this paper. A miniature extrinsic FP interferometric (EFPI) sensor was fabricated by using an approximate 8-layer graphene diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule with an inner diameter of 125 μm, and van der Waals interactions between the graphene diaphragm and its substrate created a low finesse FP interferometer with a cavity length of 36.13 μm. Double reference FP cavities using two cleaved optical fibers as reflectors were also constructed to differentially cancel the thermal expansion effects of the trapped gas and adhesive material. A temperature test demonstrated an approximate cavity length change of 166.1 nm °C‑1 caused by film thermal expansion in the range of 20–60 °C. Then along with the established thermal deformation model of the suspended circular diaphragm, the calculated CTE ranging from ‑9.98 × 10‑6 K‑1 to ‑2.09 × 10‑6 K‑1 conformed well to the previously measured results. The proposed method would be applicable in other types of elastic materials as the sensitive diaphragm of an EFPI sensor over a wide temperature range.
The chaperone co-inducer BGP-15 alleviates ventilation-induced diaphragm dysfunction.
Salah, Heba; Li, Meishan; Cacciani, Nicola; Gastaldello, Stefano; Ogilvie, Hannah; Akkad, Hazem; Namuduri, Arvind Venkat; Morbidoni, Valeria; Artemenko, Konstantin A; Balogh, Gabor; Martinez-Redondo, Vicente; Jannig, Paulo; Hedström, Yvette; Dworkin, Barry; Bergquist, Jonas; Ruas, Jorge; Vigh, Laszlo; Salviati, Leonardo; Larsson, Lars
Ventilation-induced diaphragm dysfunction (VIDD) is a marked decline in diaphragm function in response to mechanical ventilation, which has negative consequences for individual patients' quality of life and for the health care system, but specific treatment strategies are still lacking. We used an experimental intensive care unit (ICU) model, allowing time-resolved studies of diaphragm structure and function in response to long-term mechanical ventilation and the effects of a pharmacological intervention (the chaperone co-inducer BGP-15). The marked loss of diaphragm muscle fiber function in response to mechanical ventilation was caused by posttranslational modifications (PTMs) of myosin. In a rat model, 10 days of BGP-15 treatment greatly improved diaphragm muscle fiber function (by about 100%), although it did not reverse diaphragm atrophy. The treatment also provided protection from myosin PTMs associated with HSP72 induction and PARP-1 inhibition, resulting in improvement of mitochondrial function and content. Thus, BGP-15 may offer an intervention strategy for reducing VIDD in mechanically ventilated ICU patients. PMID:27488897
An analytical solution for curved piezoelectric micromachined ultrasonic transducers with spherically shaped diaphragms.
Sammoura, Firas; Akhbari, Sina; Lin, Liwei
An analytical solution for piezoelectrically actuated spherically shaped diaphragms has been developed to study their dynamic behavior with targeted applications in piezoelectric micromachined ultrasonic transducers (pMUT). The analytical model starts with a curved pMUT composed of a piezoelectric diaphragm with a nominal radius in size, a radius of curvature in shape, and under both possible actuation sources of radial pressure and electric potential. The diaphragm has the piezoelectric material polarized in the direction perpendicular to its surface and sandwiched between two metal electrodes. When an electric field is applied between the two electrodes, the in-plane piezoelectric strain can cause larger out-of-plane deflections than a flat unimorph piezoelectric diaphragm because of the diaphragm's spherical curvature with a clamped periphery for high electromechanical coupling factor. Key performance parameters, including mechanical mode shapes, resonant frequencies, dynamic responses, and displacements, with respect to the curvature and size of the diaphragm have been investigated. Both analytical derivations and numerical simulations using finite element analysis have been performed for the optimal design of the electromechanical coupling factor, with varying factors such as mechanical resonant frequency, radius of curvature, nominal radius, and thickness. As such, this work provides theoretical foundations for the design of curved pMUTs with high electromechanical coupling factor compared with planar-shape pMUTs. PMID:25167153
Estimation of vibration frequency of loudspeaker diaphragm by parallel phase-shifting digital holography
NASA Astrophysics Data System (ADS)
Kakue, T.; Endo, Y.; Shimobaba, T.; Ito, T.
We report frequency estimation of loudspeaker diaphragm vibrating at high speed by parallel phase-shifting digital holography which is a technique of single-shot phase-shifting interferometry. This technique records multiple phaseshifted holograms required for phase-shifting interferometry by using space-division multiplexing. We constructed a parallel phase-shifting digital holography system consisting of a high-speed polarization-imaging camera. This camera has a micro-polarizer array which selects four linear polarization axes for 2 × 2 pixels. We set a loudspeaker as an object, and recorded vibration of diaphragm of the loudspeaker by the constructed system. By the constructed system, we demonstrated observation of vibration displacement of loudspeaker diaphragm. In this paper, we aim to estimate vibration frequency of the loudspeaker diaphragm by applying the experimental results to frequency analysis. Holograms consisting of 128 × 128 pixels were recorded at a frame rate of 262,500 frames per second by the camera. A sinusoidal wave was input to the loudspeaker via a phone connector. We observed displacement of the loudspeaker diaphragm vibrating by the system. We also succeeded in estimating vibration frequency of the loudspeaker diaphragm by applying frequency analysis to the experimental results.
Action of the isolated canine diaphragm on the lower ribs at high lung volumes
De Troyer, André; Wilson, Theodore A
The normal diaphragm has an inspiratory action on the lower ribs, but subjects with chronic obstructive pulmonary disease commonly have an inward displacement of the lateral portions of the lower rib cage during inspiration. This paradoxical displacement, conventionally called 'Hoover's sign', has traditionally been attributed to the direct action of radially oriented diaphragmatic muscle fibres. In the present study, the inspiratory intercostal muscles in all interspaces in anaesthetized dogs were severed so that the diaphragm was the only muscle active during inspiration. The displacements of the lower ribs along the craniocaudal and laterolateral axes and the changes in pleural pressure (ΔPpl) and transdiaphragmatic pressure were measured during occluded breaths and mechanical ventilation at different lung volumes between functional residual capacity (FRC) and total lung capacity. From these data, the separate effects on rib displacement of ΔPpl and of the force exerted by the diaphragm on the ribs were determined. Isolated spontaneous diaphragm contraction at FRC displaced the lower ribs cranially and outward, but this motion was progressively reversed into a caudal and inward motion as lung volume increased. However, although the force exerted by the diaphragm on the ribs decreased with increasing volume, it continued to displace the ribs cranially and outward. These observations suggest that Hoover's sign is usually caused by the decrease in the zone of apposition and, thus, by the dominant effect of ΔPpl on the lower ribs, rather than an inward pull from the diaphragm. PMID:25063819
Energy harvester array using piezoelectric circular diaphragm for rail vibration
NASA Astrophysics Data System (ADS)
Wang, Wei; Huang, Rong-Jin; Huang, Chuan-Jun; Li, Lai-Feng
Generating electric energy from mechanical vibration using a piezoelectric circular membrane array is presented in this paper. The electrical characteristics of the functional array consisted of three plates with varies tip masses are examined under dynamic conditions. With an optimal load resistor of 11 kΩ, an output power of 21.4 mW was generated from the array in parallel connection at 150 Hz under a pre-stress of 0.8 N and a vibration acceleration of 9.8 m/s2. Moreover, the broadband energy harvesting using this array still can be realized with different tip masses. Three obvious output power peaks can be obtained in a frequency spectra of 110 Hz to 260 Hz. The results show that using a piezoelectric circular diaphragm array can increase significantly the output of energy compared with the use of a single plate. And by optimizing combination of tip masses with piezoelectric elements in array, the frequency range can be tuned to meet the broadband vibration. This array may possibly be exploited to design the energy harvesting for practical applications such as future high speed rail.
New perspectives on the renal slit diaphragm protein podocin
Relle, Manfred; Cash, Hannes; Brochhausen, Christoph; Strand, Dennis; Menke, Julia; Galle, Peter R; Schwarting, Andreas
Podocin is a critical component of the glomerular filtration barrier, its mutations causing recessive steroid-resistant nephrotic syndrome. A GenBank analysis of the human podocin (NPHS2) gene resulted in the possible existence of a new splice variant of podocin in the kidney, missing the in-frame of exon 5, encoding the prohibitin homology domain. Using RT–polymerase chain reaction and immunoblotting followed by sequence analysis, we are for the first time able to prove the expression of a novel podocin isoform (isoform 2), exclusively and constitutively expressed in human podocytes. Furthermore, we reveal singular extrarenal podocin expression in human and murine testis. Our data show the Sertoli cells of the seminiferous tubules to be the origin of testicular podocin. Confocal laser microscopy illustrates the co-localization of podocin with filamentous actin within Sertoli cells, suggesting a role of podocin in the blood/testis barrier. These results led to the rationale to examine podocin expression in testes of men with Sertoli cell-only syndrome, a disorder characterized by azoospermia. Interestingly, we observed a complete down-regulation of podocin mRNA in Sertoli cell-only syndrome, indicating a possible role of podocin in the pathogenesis of this germinal aplasia. Men with Sertoli cell-only syndrome show normal renal podocin expression, suggesting an alternate regulation of the testicular promoter. Our findings may change the perception of podocin and give new insights into the ultrastructure of glomerular slit diaphragm and the blood/testis barrier. PMID:21499232
Spontaneous recovery from depolarizing drugs in rat diaphragm.
Creese, R; Mitchell, L D
1. The end-plate region in surface fibres of rat diaphragm was located by the use of polarizing filters. 2. Carbachol (100 microM) produced depolarization at the end-plate to -55 mV, as shown by continuous recording, with some indication of spontaneous recovery in the presence of the drug. The miniature end-plate potentials disappeared and remained absent. 3. By repeated sampling it was found that the resting potential at the end-plate had largely recovered after 45 min in the presence of carbachol. Individual fibres showed much variation in the rate of recovery, and in some fibres the repolarization was rapid. 4. In the absence of K, carbachol produced depolarization at the end-plate without significant recovery, as shown by repeated sampling. 5. When muscles were exposed to ouabain (100 microM) in addition to carbachol the end-plate remained depolarized without recovery for 60 min. The effect of ouabain was reversible: withdrawal of ouabain (in the presence of carbachol) led to substantial recovery. 6. Suberyldicholine (100 microM) gave results which were similar to those produced by carbachol. 7. It was inferred that the spontaneous recovery of membrane potential in the presence of carbachol and of suberyldicholine is a process which is sensitive to K and to ouabain. Images Plate 1 PMID:7277216
Optimization of PZT Diaphragm Pump for the Convective Gyroscope
NASA Astrophysics Data System (ADS)
Dau, Van Thanh; Dao, Dzung Viet; Dinh, Thien Xuan; Shiozawa, Tatsuo; Sugiyama, Susumu
In this paper, we present the optimization of the PZT diaphragm pump for application in gas gyroscope. A circular flow inside the sealed case is simulated in detail by utilizing 3D compressible flow with the interaction of fluid-solid phase and the transient analysis is employed. The working principle and the effect of the jet-pump integrated inside the sensor are explained and validated by experiments using anemometry technique. The results verified that configuration of the pump is optimized and the peak velocity of the flow at the sensing element is 3.5m/sec after starting the pump 3.6ms. A novel structure of the sensing element of the gas gyroscope, consists of thermistor and heater, is also reported. The thermistor is heated by a separate heater, whose power is supplied independently form that of thermistor. This design allows low voltage on the thermistor, therefore the noise is reduced. Both heater and thermistor are optimized in order to reduce the thermal induced stress which occurred in the old thermistors at working temperatures. The thermal stress appeared in p-type silicon thermistors reduced the performance of sensor by 7.5%, which is calculated and experimentally confirmed.
Prevalence and histopathological finding of thin-walled and thick-walled Sarcocysts in slaughtered cattle of Karaj abattoir, Iran.
Nourollahi-Fard, Saeid R; Kheirandish, Reza; Sattari, Saeid
Sarcocystosis is a zoonotic disease caused by Sarcocystis spp. with obligatory two host life cycle generally alternating between an herbivorous intermediate host and a carnivorous definitive host. Some species of this coccidian parasite can cause considerable morbidity and mortality in cattle. The present study was set to investigate the prevalence of Sarcocystis spp. and type of cyst wall in slaughtered cattle of Karaj abattoir, Iran. For this purpose 125 cattle (88 males and 37 females) were investigated for the presence of macroscopic and microscopic Sarcocystis cysts in muscular tissues. No macroscopic Sarcocystis cysts were found in any of the samples. In light microscopy, 121 out of 125 cattle (96.8 %) had thin-walled cysts of Sarcocystis cruzi, while 43 out of them (34.4 %) had thick-walled Sarcocystis cyst. In this survey, the most infected tissue was esophagus and heart and the less was diaphragm. Thin-walled cysts (S. cruzi) mostly found in heart and skeletal muscle showed the less. However, thick-walled cyst (S. hominis or S. hirsuta) mostly were detected in diaphragm, heart muscle showed no thick-walled cyst. No significant relation was observed between age and sex and the rate of infection. The results showed that Sarcocystis cyst is prevalent in cattle in the North part of Iran and the evaluation of infection potential can be useful when considering control programs. PMID:26064016
Inhibition of Janus kinase signaling during controlled mechanical ventilation prevents ventilation-induced diaphragm dysfunction
Smith, Ira J.; Godinez, Guillermo L.; Singh, Baljit K.; McCaughey, Kelly M.; Alcantara, Raniel R.; Gururaja, Tarikere; Ho, Melissa S.; Nguyen, Henry N.; Friera, Annabelle M.; White, Kathy A.; McLaughlin, John R.; Hansen, Derek; Romero, Jason M.; Baltgalvis, Kristen A.; Claypool, Mark D.; Li, Wei; Lang, Wayne; Yam, George C.; Gelman, Marina S.; Ding, Rongxian; Yung, Stephanie L.; Creger, Daniel P.; Chen, Yan; Singh, Rajinder; Smuder, Ashley J.; Wiggs, Michael P.; Kwon, Oh-Sung; Sollanek, Kurt J.; Powers, Scott K.; Masuda, Esteban S.; Taylor, Vanessa C.; Payan, Donald G.; Kinoshita, Taisei; Kinsella, Todd M.
Controlled mechanical ventilation (CMV) is associated with the development of diaphragm atrophy and contractile dysfunction, and respiratory muscle weakness is thought to contribute significantly to delayed weaning of patients. Therefore, therapeutic strategies for preventing these processes may have clinical benefit. The aim of the current study was to investigate the role of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in CMV-mediated diaphragm wasting and weakness in rats. CMV-induced diaphragm atrophy and contractile dysfunction coincided with marked increases in STAT3 phosphorylation on both tyrosine 705 (Tyr705) and serine 727 (Ser727). STAT3 activation was accompanied by its translocation into mitochondria within diaphragm muscle and mitochondrial dysfunction. Inhibition of JAK signaling during CMV prevented phosphorylation of both target sites on STAT3, eliminated the accumulation of phosphorylated STAT3 within the mitochondria, and reversed the pathologic alterations in mitochondrial function, reduced oxidative stress in the diaphragm, and maintained normal diaphragm contractility. In addition, JAK inhibition during CMV blunted the activation of key proteolytic pathways in the diaphragm, as well as diaphragm atrophy. These findings implicate JAK/STAT3 signaling in the development of diaphragm muscle atrophy and dysfunction during CMV and suggest that the delayed extubation times associated with CMV can be prevented by inhibition of Janus kinase signaling.—Smith, I. J., Godinez, G. L., Singh, B. K., McCaughey, K. M., Alcantara, R. R., Gururaja, T., Ho, M. S., Nguyen, H. N., Friera, A. M., White, K. A., McLaughlin, J. R., Hansen, D., Romero, J. M., Baltgalvis, K. A., Claypool, M. D., Li, W., Lang, W., Yam, G. C., Gelman, M. S., Ding, R., Yung, S. L., Creger, D. P., Chen, Y., Singh, R., Smuder, A. J., Wiggs, M. P., Kwon, O.-S., Sollanek, K. J., Powers, S. K., Masuda, E. S., Taylor, V. C., Payan, D. G
Mechanical ventilation reduces rat diaphragm blood flow and impairs O2 delivery and uptake
Davis, Robert T.; Bruells, Christian S.; Stabley, John N.; McCullough, Danielle J.; Powers, Scott K.; Behnke, Bradley J.
Objectives Although mechanical ventilation (MV) is a life-saving intervention in patients suffering from respiratory failure, prolonged MV is often associated with numerous complications including problematic weaning. In contracting skeletal muscle, inadequate O2 supply can limit oxidative phosphorylation resulting in muscular fatigue. However, whether prolonged MV results in decreased diaphragmatic blood and induces an O2 supply-demand imbalance in the diaphragm remains unknown. Design We tested the hypothesis that prolonged controlled MV results in a time-dependent reduction in rat diaphragmatic blood flow and microvascular PO2 and that prolonged MV would diminish the diaphragm's ability to increase blood flow in response to muscular contractions. Measurements and Main Results Compared to 30 min of MV, 6 hrs of MV resulted in a 75% reduction in diaphragm blood flow (via radiolabeled microspheres), which did not occur in the intercostal muscle or high-oxidative hindlimb muscle (e.g., soleus). There was also a time-dependent decline in diaphragm microvascular PO2 (via phosphorescence quenching). Further, when contrasted to 30 min of MV, 6 hrs of MV significantly compromised the diaphragm's ability to increase blood flow during electrically-induced contractions which resulted in a ~80% reduction in diaphragm O2 uptake. In contrast, 6 hrs of spontaneous breathing in anesthetized animals did not alter diaphragm blood flow or the ability to augment flow during electrically-induced contractions. Conclusions These new and important findings reveal that prolonged MV results in a time-dependent decrease in the ability of the diaphragm to augment blood flow to match O2 demand in response to contractile activity and could be a key contributing factor to difficult weaning. Although additional experiments are required to confirm, it is tempting to speculate that this ventilator-induced decline in diaphragmatic oxygenation could promote a hypoxia-induced generation of
Reduced force of diaphragm muscle fibers in patients with chronic thromboembolic pulmonary hypertension.
Manders, Emmy; Bonta, Peter I; Kloek, Jaap J; Symersky, Petr; Bogaard, Harm-Jan; Hooijman, Pleuni E; Jasper, Jeff R; Malik, Fady I; Stienen, Ger J M; Vonk-Noordegraaf, Anton; de Man, Frances S; Ottenheijm, Coen A C
Patients with pulmonary hypertension (PH) suffer from inspiratory muscle weakness. However, the pathophysiology of inspiratory muscle dysfunction in PH is unknown. We hypothesized that weakness of the diaphragm, the main inspiratory muscle, is an important contributor to inspiratory muscle dysfunction in PH patients. Our objective was to combine ex vivo diaphragm muscle fiber contractility measurements with measures of in vivo inspiratory muscle function in chronic thromboembolic pulmonary hypertension (CTEPH) patients. To assess diaphragm muscle contractility, function was studied in vivo by maximum inspiratory pressure (MIP) and ex vivo in diaphragm biopsies of the same CTEPH patients (N = 13) obtained during pulmonary endarterectomy. Patients undergoing elective lung surgery served as controls (N = 15). Muscle fiber cross-sectional area (CSA) was determined in cryosections and contractility in permeabilized muscle fibers. Diaphragm muscle fiber CSA was not significantly different between control and CTEPH patients in both slow-twitch and fast-twitch fibers. Maximal force-generating capacity was significantly lower in slow-twitch muscle fibers of CTEPH patients, whereas no difference was observed in fast-twitch muscle fibers. The maximal force of diaphragm muscle fibers correlated significantly with MIP. The calcium sensitivity of force generation was significantly reduced in fast-twitch muscle fibers of CTEPH patients, resulting in a ∼40% reduction of submaximal force generation. The fast skeletal troponin activator CK-2066260 (5 μM) restored submaximal force generation to levels exceeding those observed in control subjects. In conclusion, diaphragm muscle fiber contractility is hampered in CTEPH patients and contributes to the reduced function of the inspiratory muscles in CTEPH patients. PMID:27190061
Janus kinase inhibition prevents cancer- and myocardial infarction-mediated diaphragm muscle weakness in mice.
Smith, Ira J; Roberts, Brandon; Beharry, Adam; Godinez, Guillermo L; Payan, Donald G; Kinsella, Todd M; Judge, Andrew R; Ferreira, Leonardo F
Respiratory dysfunction is prevalent in critically ill patients and can lead to adverse clinical outcomes, including respiratory failure and increased mortality. Respiratory muscles, which normally sustain respiration through inspiratory muscle contractions, become weakened during critical illness, and recent studies suggest that respiratory muscle weakness is related to systemic inflammation. Here, we investigate the pathophysiological role of the inflammatory JAK1/3 signaling pathway in diaphragm weakness in two distinct experimental models of critical illness. In the first experiment, mice received subcutaneous injections of PBS or C26 cancer cells and were fed chow formulated with or without the JAK1/3 inhibitor R548 for 26 days. Diaphragm specific force was significantly reduced in tumor-bearing mice receiving standard chow; however, treatment with the JAK1/3 inhibitor completely prevented diaphragm weakness. Diaphragm cross-sectional area was diminished by ∼25% in tumor-bearing mice but was similar to healthy mice in tumor-bearing animals treated with R548. In the second study, mice received sham surgery or coronary artery ligation, leading to myocardial infarction (MI), and were treated with R548 or vehicle 1 h postsurgery, and once daily for 3 days. Diaphragm specific force was comparable between sham surgery/vehicle, sham surgery/R548 and MI/R548 groups, but significantly decreased in the MI/vehicle group. Markers of oxidative damage and activated caspase-3, mechanisms previously identified to reduce muscle contractility, were not elevated in diaphragm extracts. These experiments implicate JAK1/3 signaling in cancer- and MI-mediated diaphragm weakness in mice, and provide a compelling case for further investigation. PMID:26864813
Janus kinase inhibition prevents cancer- and myocardial infarction-mediated diaphragm muscle weakness in mice
Smith, Ira J.; Roberts, Brandon; Beharry, Adam; Godinez, Guillermo L.; Payan, Donald G.; Judge, Andrew R.; Ferreira, Leonardo F.
Respiratory dysfunction is prevalent in critically ill patients and can lead to adverse clinical outcomes, including respiratory failure and increased mortality. Respiratory muscles, which normally sustain respiration through inspiratory muscle contractions, become weakened during critical illness, and recent studies suggest that respiratory muscle weakness is related to systemic inflammation. Here, we investigate the pathophysiological role of the inflammatory JAK1/3 signaling pathway in diaphragm weakness in two distinct experimental models of critical illness. In the first experiment, mice received subcutaneous injections of PBS or C26 cancer cells and were fed chow formulated with or without the JAK1/3 inhibitor R548 for 26 days. Diaphragm specific force was significantly reduced in tumor-bearing mice receiving standard chow; however, treatment with the JAK1/3 inhibitor completely prevented diaphragm weakness. Diaphragm cross-sectional area was diminished by ∼25% in tumor-bearing mice but was similar to healthy mice in tumor-bearing animals treated with R548. In the second study, mice received sham surgery or coronary artery ligation, leading to myocardial infarction (MI), and were treated with R548 or vehicle 1 h postsurgery, and once daily for 3 days. Diaphragm specific force was comparable between sham surgery/vehicle, sham surgery/R548 and MI/R548 groups, but significantly decreased in the MI/vehicle group. Markers of oxidative damage and activated caspase-3, mechanisms previously identified to reduce muscle contractility, were not elevated in diaphragm extracts. These experiments implicate JAK1/3 signaling in cancer- and MI-mediated diaphragm weakness in mice, and provide a compelling case for further investigation. PMID:26864813
Time course analysis of mechanical ventilation-induced diaphragm contractile muscle dysfunction in the rat
Corpeno, R; Dworkin, B; Cacciani, N; Salah, H; Bergman, H-M; Ravara, B; Vitadello, M; Gorza, L; Gustafson, A-M; Hedström, Y; Petersson, J; Feng, H-Z; Jin, J-P; Iwamoto, H; Yagi, N; Artemenko, K; Bergquist, J; Larsson, L
Controlled mechanical ventilation (CMV) plays a key role in triggering the impaired diaphragm muscle function and the concomitant delayed weaning from the respirator in critically ill intensive care unit (ICU) patients. To date, experimental and clinical studies have primarily focused on early effects on the diaphragm by CMV, or at specific time points. To improve our understanding of the mechanisms underlying the impaired diaphragm muscle function in response to mechanical ventilation, we have performed time-resolved analyses between 6 h and 14 days using an experimental rat ICU model allowing detailed studies of the diaphragm in response to long-term CMV. A rapid and early decline in maximum muscle fibre force and preceding muscle fibre atrophy was observed in the diaphragm in response to CMV, resulting in an 85% reduction in residual diaphragm fibre function after 9–14 days of CMV. A modest loss of contractile proteins was observed and linked to an early activation of the ubiquitin proteasome pathway, myosin:actin ratios were not affected and the transcriptional regulation of myosin isoforms did not show any dramatic changes during the observation period. Furthermore, small angle X-ray diffraction analyses demonstrate that myosin can bind to actin in an ATP-dependent manner even after 9–14 days of exposure to CMV. Thus, quantitative changes in muscle fibre size and contractile proteins are not the dominating factors underlying the dramatic decline in diaphragm muscle function in response to CMV, in contrast to earlier observations in limb muscles. The observed early loss of subsarcolemmal neuronal nitric oxide synthase activity, onset of oxidative stress, intracellular lipid accumulation and post-translational protein modifications strongly argue for significant qualitative changes in contractile proteins causing the severely impaired residual function in diaphragm fibres after long-term mechanical ventilation. For the first time, the present study
Theoretical Evaluation of Electroactive Polymer Based Micropump Diaphragm for Air Flow Control
NASA Technical Reports Server (NTRS)
Xu, Tian-Bing; Su, Ji; Zhang, Qiming
An electroactive polymer (EAP), high energy electron irradiated poly(vinylidene fluoride-trifluoroethylene) [P(VDFTrFE)] copolymer, based actuation micropump diaphragm (PAMPD) have been developed for air flow control. The displacement strokes and profiles as a function of amplifier and frequency of electric field have been characterized. The volume stroke rates (volume rate) as function of electric field, driving frequency have been theoretically evaluated, too. The PAMPD exhibits high volume rate. It is easily tuned with varying of either amplitude or frequency of the applied electric field. In addition, the performance of the diaphragms were modeled and the agreement between the modeling results and experimental data confirms that the response of the diaphragms follow the design parameters. The results demonstrated that the diaphragm can fit some future aerospace applications to replace the traditional complex mechanical systems, increase the control capability and reduce the weight of the future air dynamic control systems. KEYWORDS: Electroactive polymer (EAP), micropump, diaphragm, actuation, displacement, volume rate, pumping speed, clamping ratio.
Plastic Deformation of Micromachined Silicon Diaphragms with a Sealed Cavity at High Temperatures
Ren, Juan; Ward, Michael; Kinnell, Peter; Craddock, Russell; Wei, Xueyong
Single crystal silicon (SCS) diaphragms are widely used as pressure sensitive elements in micromachined pressure sensors. However, for harsh environments applications, pure silicon diaphragms are hardly used because of the deterioration of SCS in both electrical and mechanical properties. To survive at the elevated temperature, the silicon structures must work in combination with other advanced materials, such as silicon carbide (SiC) or silicon on insulator (SOI), for improved performance and reduced cost. Hence, in order to extend the operating temperatures of existing SCS microstructures, this work investigates the mechanical behavior of pressurized SCS diaphragms at high temperatures. A model was developed to predict the plastic deformation of SCS diaphragms and was verified by the experiments. The evolution of the deformation was obtained by studying the surface profiles at different anneal stages. The slow continuous deformation was considered as creep for the diaphragms with a radius of 2.5 mm at 600 °C. The occurrence of plastic deformation was successfully predicted by the model and was observed at the operating temperature of 800 °C and 900 °C, respectively. PMID:26861332
Oxidative stress is required for mechanical ventilation-induced protease activation in the diaphragm
Smuder, Ashley J.; Wu, Min; Hudson, Matthew B.; Nelson, W. Bradley; Powers, Scott K.
Prolonged mechanical ventilation (MV) results in diaphragmatic weakness due to fiber atrophy and contractile dysfunction. Recent work reveals that activation of the proteases calpain and caspase-3 is required for MV-induced diaphragmatic atrophy and contractile dysfunction. However, the mechanism(s) responsible for activation of these proteases remains unknown. To address this issue, we tested the hypothesis that oxidative stress is essential for the activation of calpain and caspase-3 in the diaphragm during MV. Cause-and-effect was established by prevention of MV-induced diaphragmatic oxidative stress using the antioxidant Trolox. Treatment of animals with Trolox prevented MV-induced protein oxidation and lipid peroxidation in the diaphragm. Importantly, the Trolox-mediated protection from MV-induced oxidative stress prevented the activation of calpain and caspase-3 in the diaphragm during MV. Furthermore, the avoidance of MV-induced oxidative stress not only averted the activation of these proteases but also rescued the diaphragm from MV-induced diaphragmatic myofiber atrophy and contractile dysfunction. Collectively, these findings support the prediction that oxidative stress is required for MV-induced activation of calpain and caspase-3 in the diaphragm and are consistent with the concept that antioxidant therapy can retard MV-induced diaphragmatic weakness. PMID:20203072
Diaphragm motion characterization using chest motion data for biomechanics-based lung tumor tracking during EBRT
NASA Astrophysics Data System (ADS)
Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas
Despite recent advances in image-guided interventions, lung cancer External Beam Radiation Therapy (EBRT) is still very challenging due to respiration induced tumor motion. Among various proposed methods of tumor motion compensation, real-time tumor tracking is known to be one of the most effective solutions as it allows for maximum normal tissue sparing, less overall radiation exposure and a shorter treatment session. As such, we propose a biomechanics-based real-time tumor tracking method for effective lung cancer radiotherapy. In the proposed algorithm, the required boundary conditions for the lung Finite Element model, including diaphragm motion, are obtained using the chest surface motion as a surrogate signal. The primary objective of this paper is to demonstrate the feasibility of developing a function which is capable of inputting the chest surface motion data and outputting the diaphragm motion in real-time. For this purpose, after quantifying the diaphragm motion with a Principal Component Analysis (PCA) model, correlation coefficient between the model parameters of diaphragm motion and chest motion data was obtained through Partial Least Squares Regression (PLSR). Preliminary results obtained in this study indicate that the PCA coefficients representing the diaphragm motion can be obtained through chest surface motion tracking with high accuracy.
Plastic Deformation of Micromachined Silicon Diaphragms with a Sealed Cavity at High Temperatures.
Ren, Juan; Ward, Michael; Kinnell, Peter; Craddock, Russell; Wei, Xueyong
Single crystal silicon (SCS) diaphragms are widely used as pressure sensitive elements in micromachined pressure sensors. However, for harsh environments applications, pure silicon diaphragms are hardly used because of the deterioration of SCS in both electrical and mechanical properties. To survive at the elevated temperature, the silicon structures must work in combination with other advanced materials, such as silicon carbide (SiC) or silicon on insulator (SOI), for improved performance and reduced cost. Hence, in order to extend the operating temperatures of existing SCS microstructures, this work investigates the mechanical behavior of pressurized SCS diaphragms at high temperatures. A model was developed to predict the plastic deformation of SCS diaphragms and was verified by the experiments. The evolution of the deformation was obtained by studying the surface profiles at different anneal stages. The slow continuous deformation was considered as creep for the diaphragms with a radius of 2.5 mm at 600 °C. The occurrence of plastic deformation was successfully predicted by the model and was observed at the operating temperature of 800 °C and 900 °C, respectively. PMID:26861332
Diaphragm opening effects on shock wave formation and acceleration in a rectangular cross section channel
NASA Astrophysics Data System (ADS)
Pakdaman, S. A.; Garcia, M.; Teh, E.; Lincoln, D.; Trivedi, M.; Alves, M.; Johansen, C.
Shock wave formation and acceleration in a high-aspect ratio cross section shock tube were studied experimentally and numerically. The relative importance of geometric effects and diaphragm opening time on shock formation are assessed. The diaphragm opening time was controlled through the use of slit-type (fast opening time) and petal-type (slow opening time) diaphragms. A novel method of fabricating the petal-type diaphragms, which results in a consistent burst pressure and symmetric opening without fragmentation, is presented. High-speed schlieren photography was used to visualize the unsteady propagation of the lead shock wave and trailing gas dynamic structures. Surface-mounted pressure sensors were used to capture the spatial and temporal development of the pressure field. Unsteady Reynolds-Averaged Navier-Stokes simulation predictions using the shear-stress-transport turbulence model are compared to the experimental data. Simulation results are used to explain the presence of high-frequency pressure oscillations observed experimentally in the driver section as well as the cause of the initial acceleration and subsequent rapid decay of shock velocity measured along the top and bottom channel surfaces. A one-dimensional theoretical model predicting the effect of the finite opening time of the diaphragm on the rate of driver depressurization and shock acceleration is proposed. The model removes the large amount of empiricism that accompanies existing models published in the literature. Model accuracy is assessed through comparisons with experiments and simulations. Limitations of and potential improvements in the model are discussed.
Assessing breathing motion by shape matching of lung and diaphragm surfaces
NASA Astrophysics Data System (ADS)
Urschler, Martin; Bischof, Horst
Studying complex thorax breating motion is an important research topic for accurate fusion of functional and anatomical data, radiotherapy planning or reduction of breathing motion artifacts. We investigate segmented CT lung, airway and diaphragm surfaces at several different breathing states between Functional Residual and Total Lung Capacity. In general, it is hard to robustly derive corresponding shape features like curvature maxima from lung and diaphragm surfaces since diaphragm and rib cage muscles tend to deform the elastic lung tissue such that e.g. ridges might disappear. A novel registration method based on the shape context approach for shape matching is presented where we extend shape context to 3D surfaces. The shape context approach was reported as a promising method for matching 2D shapes without relying on extracted shape features. We use the point correspondences for a non-rigid thin-plate-spline registration to get deformation fields that describe the movement of lung and diaphragm. Our validation consists of experiments on phantom and real sheep thorax data sets. Phantom experiments make use of shapes that are manipulated with known transformations that simulate breathing behaviour. Real thorax data experiments use a data set showing lungs and diaphragm at 5 distinct breathing states, where we compare subsets of the data sets and qualitatively and quantitatively asses the registration performance by using manually identified corresponding landmarks.
Mechanostimulation, electrostimulation and force measurement in an in vitro model of the isolated rat diaphragm.
Armbruster, Caroline; Dassow, Constanze; Gamerdinger, Katharina; Schneider, Matthias; Sumkauskaite, Migle; Guttmann, Josef; Schumann, Stefan
In an in vitro model of the entire rat diaphragm, diaphragmatic contraction forces at defined preload levels were investigated. A total of 24 excised rat diaphragms were electrically stimulated inside a two-chamber strain-applicator. The resulting contraction forces were determined on eight adjusted preload levels via measuring the elicited pressure in the chamber below the diaphragm. Subsequently, diaphragms were exposed for 6 h to one of four treatments: (1) control, (2) cyclic mechanical stretch, (3) intermittent electrical stimulation or (4) combination of cyclic mechanical stretch and electrical stimulation. Diaphragmatic contraction force increased from 116 ± 21 mN at the lowest preload level to 775 ± 85 mN at the maximal preload level. After 6 h maximal muscle contraction forces were smallest after non-electrostimulated treatment (control: 81 ± 15 mN, mechanical deflection: 94 ± 12 mN) and largest after electrostimulation treatment (mere electrostimulation: 165 ± 20 mN, combined mechano- and electro-stimulation: 164 ± 14 mN). We conclude that our model allows force measurements on isolated rat diaphragms. Furthermore, we conclude that by intermediate electrical stimulation diaphragmatic force generation was better preserved than by mechanical stimulation. PMID:22033209
ERIC Educational Resources Information Center
Greenman, Jim
In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…
NAD(P)H oxidase subunit p47phox is elevated, and p47phox knockout prevents diaphragm contractile dysfunction in heart failure.
Ahn, Bumsoo; Beharry, Adam W; Frye, Gregory S; Judge, Andrew R; Ferreira, Leonardo F
Patients with chronic heart failure (CHF) have dyspnea and exercise intolerance, which are caused in part by diaphragm abnormalities. Oxidants impair diaphragm contractile function, and CHF increases diaphragm oxidants. However, the specific source of oxidants and its relevance to diaphragm abnormalities in CHF is unclear. The p47(phox)-dependent Nox2 isoform of NAD(P)H oxidase is a putative source of diaphragm oxidants. Thus, we conducted our study with the goal of determining the effects of CHF on the diaphragm levels of Nox2 complex subunits and test the hypothesis that p47(phox) knockout prevents diaphragm contractile dysfunction elicited by CHF. CHF caused a two- to sixfold increase (P < 0.05) in diaphragm mRNA and protein levels of several Nox2 subunits, with p47(phox) being upregulated and hyperphosphorylated. CHF increased diaphragm extracellular oxidant emission in wild-type but not p47(phox) knockout mice. Diaphragm isometric force, shortening velocity, and peak power were decreased by 20-50% in CHF wild-type mice (P < 0.05), whereas p47(phox) knockout mice were protected from impairments in diaphragm contractile function elicited by CHF. Our experiments show that p47(phox) is upregulated and involved in the increased oxidants and contractile dysfunction in CHF diaphragm. These findings suggest that a p47(phox)-dependent NAD(P)H oxidase mediates the increase in diaphragm oxidants and contractile dysfunction in CHF. PMID:26209274
Myosin heavy chain composition in the rat diaphragm - Effect of age and exercise training
NASA Technical Reports Server (NTRS)
Gosselin, Luc E.; Betlach, Michael; Vailas, Arthur C.; Greaser, Marion L.; Thomas, D. P.
The effects of aging and exercise training on the myosin heavy chain (MHC) composition were determined in both the costal and crural diaphragm regions of female Fischer 344 rats. Treadmill running at 75 percent maximal oxygen consumption resulted in similar increases in plantaris muscle citrate synthase activity in both young (5 mo) and old (23mo) trained animals (P less than 0.05). It was found that the ratio of fast to slow MHC was significantly higher (P less than 0.005) in the crural compared with costal diaphragm region in both age groups. A significant age-related increase in persentage of slow MHC was observed in both diaphragm regions. The relative proportion of slow MHC in either costal or crural region was not changed by exercise training.
Discharge ignition in the diaphragm configuration supplied by DC non-pulsing voltage
NASA Astrophysics Data System (ADS)
Hlochová, L.; Hlavatá, L.; Kozáková, Z.; Krčma, F.
This work deals with the ignition of the discharge in the diaphragm configuration generated in water solutions containing supporting NaCl electrolyte. The reactor has volume of 110 ml and it is made of polycarbonate. HV electrodes made of stainless steel are placed in this reactor. Ceramic (Shapal-MTM) diaphragm is placed in the barrier separating the cathode and the anode space. An electric power source supplies the reactor by constant DC voltage up to 4 kV and electric current up to 300 mA. The discharge ignition is compared in the reactor with different sizes of diaphragms. Measurements are carried out in electrolyte solutions with the same conductivity. Images of plasma streamers and bubble formation are taken by an ICCD camera iStar 734. Electrical characteristics are measured by an oscilloscope LeCroy LT 374 L in order to determine breakdown moments at different experimental conditions.
Methyl isocyanate liquid and vapor permeation through selected respirator diaphragms and chemical protective clothing
Berardinelli, S.P.; Moyer, E.S.
Initially, a study was undertaken to evaluate selected chemical protective clothing suitable for use by emergency response personnel confronted with methyl isocyanate (MIC). Twenty-two chemical protective clothing materials were tested against liquid methyl isocyanate. Chemical permeation breakthrough times for these clothing materials demonstrate that only one of these garments can be considered as a candidate material against liquid MIC. In a subsequent study, three chemical protective clothing materials were evaluated against approximately 800 ppm MIC vapor. Chemical permeation breakthrough times demonstrate that these materials can be considered candidate materials. A final study tested self-contained breathing apparatus (SCBA) diaphragms. Four SCBA diaphragms were tested and all experienced rapid breakthrough when exposed to liquid MIC. Next, three SCBA diaphragms were exposed to approximately 800 ppm MIC vapor. The data demonstrate that the SCBA should be worn inside a total encapsulating suit.
Calcium-dependent phospholipase A2 modulates infection-induced diaphragm dysfunction.
Supinski, Gerald S; Alimov, Alexander P; Wang, Lin; Song, Xiao-Hong; Callahan, Leigh A
Calpain activation contributes to the development of infection-induced diaphragm weakness, but the mechanisms by which infections activate calpain are poorly understood. We postulated that skeletal muscle calcium-dependent phospholipase A2 (cPLA2) is activated by cytokines and has downstream effects that induce calpain activation and muscle weakness. We determined whether cPLA2 activation mediates cytokine-induced calpain activation in isolated skeletal muscle (C2C12) cells and infection-induced diaphragm weakness in mice. C2C12 cells were treated with the following: 1) vehicle; 2) cytomix (TNF-α 20 ng/ml, IL-1β 50 U/ml, IFN-γ 100 U/ml, LPS 10 μg/ml); 3) cytomix + AACOCF3, a cPLA2 inhibitor (10 μM); or 4) AACOCF3 alone. At 24 h, we assessed cell cPLA2 activity, mitochondrial superoxide generation, calpain activity, and calpastatin activity. We also determined if SS31 (10 μg/ml), a mitochondrial superoxide scavenger, reduced cytomix-mediated calpain activation. Finally, we determined if CDIBA (10 μM), a cPLA2 inhibitor, reduced diaphragm dysfunction due to cecal ligation puncture in mice. Cytomix increased C2C12 cell cPLA2 activity (P < 0.001) and superoxide generation; AACOCF3 and SS31 blocked increases in superoxide generation (P < 0.001). Cytomix also activated calpain (P < 0.001) and inactivated calpastatin (P < 0.01); both AACOCF3 and SS31 prevented these changes. Cecal ligation puncture reduced diaphragm force in mice, and CDIBA prevented this reduction (P < 0.001). cPLA2 modulates cytokine-induced calpain activation in cells and infection-induced diaphragm weakness in animals. We speculate that therapies that inhibit cPLA2 may prevent diaphragm weakness in infected, critically ill patients. PMID:26968769
Identifying decreased diaphragmatic mobility and diaphragm thickening in interstitial lung disease: the utility of ultrasound imaging
Santana, Pauliane Vieira; Prina, Elena; Albuquerque, André Luis Pereira; Carvalho, Carlos Roberto Ribeiro; Caruso, Pedro
Objective: To investigate the applicability of ultrasound imaging of the diaphragm in interstitial lung disease (ILD). Methods: Using ultrasound, we compared ILD patients and healthy volunteers (controls) in terms of diaphragmatic mobility during quiet and deep breathing; diaphragm thickness at functional residual capacity (FRC) and at total lung capacity (TLC); and the thickening fraction (TF, proportional diaphragm thickening from FRC to TLC). We also evaluated correlations between diaphragmatic dysfunction and lung function variables. Results: Between the ILD patients (n = 40) and the controls (n = 16), mean diaphragmatic mobility was comparable during quiet breathing, although it was significantly lower in the patients during deep breathing (4.5 ± 1.7 cm vs. 7.6 ± 1.4 cm; p < 0.01). The patients showed greater diaphragm thickness at FRC (p = 0.05), although, due to lower diaphragm thickness at TLC, they also showed a lower TF (p < 0.01). The FVC as a percentage of the predicted value (FVC%) correlated with diaphragmatic mobility (r = 0.73; p < 0.01), and an FVC% cut-off value of < 60% presented high sensitivity (92%) and specificity (81%) for indentifying decreased diaphragmatic mobility. Conclusions: Using ultrasound, we were able to show that diaphragmatic mobility and the TF were lower in ILD patients than in healthy controls, despite the greater diaphragm thickness at FRC in the former. Diaphragmatic mobility correlated with ILD functional severity, and an FVC% cut-off value of < 60% was found to be highly accurate for indentifying diaphragmatic dysfunction on ultrasound. PMID:27167428
Process engineering and economic evaluations of diaphragm and membrane chlorine cell technologies. Final report
Not Available
The chlor-alkali manufacturing technologies of (1), diaphragm cells (2), current technology membrane cells (3), catalytic cathode membrane cells (4), oxygen-cathode membrane cells and to a lesser extent several other related emerging processes are studied. Comparisons have been made on the two bases of (1) conventional industrial economics, and (2) energy consumption. The current diaphragm cell may have a small economic advantage over the other technologies at the plant size of 544 metric T/D (600 T/D). The three membrane cells all consume less energy, with the oxygen-cathode cell being the lowest. The oxygen-cathode cell appears promising as a low energy chlor-alkali cell where there is no chemical market for hydrogen. Federal funding of the oxygen-cathode cell has been beneficial to the development of the technology, to electrochemical cell research, and may help maintain the US's position in the international chlor-alkali technology marketplace. Tax law changes inducing the installation of additional cells in existing plants would produce the quickest reduction in power consumption by the chlor-alkali industry. Alternative technologies such as the solid polymer electrolyte cell, the coupling of diaphragm cells with fuel cells and the dynamic gel diaphragm have a strong potential for reducing chloralkali industry power consumption. Adding up all the recent and expected improvements that have become cost-effective, the electrical energy required to produce a unit of chlorine by 1990 should be only 50% to 60% of that used in 1970. In the United States the majority of the market does not demand salt-free caustic. About 75% of the electrolytic caustic is produced in diaphragm cells and only a small part of that is purified. This study indicates that unless membrane cell costs are greatly reduced or a stronger demand develops for salt-free caustic, the diaphragm cells will remain competitive. (WHK)
Recurrence of Liver Transplantation Combined With Lung and Diaphragm Resection for Alveolar Echinococcosis: A Case Report.
Pang, C; Chu, Y K
Liver transplantation (LT) for alveolar echinococcosis (AE) with multiple-organ involvement is controversial. We report on a 31-year-old female patient suffering from AE with liver, lung, and diaphragm involvement. After an "extended" resection (liver, lung, and diaphragm were performed) combined with LT, recurrence still occurred after 6 years and the patient presented with hemoptysis. Puncture, aspiration, injection, reaspiration, and drainage (PAIRD) were performed and the effect was instantaneous. To our knowledge, no such surgical strategy for AE has previously been reported. In spite of the high risk of recurrence, choosing this surgical method is acceptable for a fatal AE and the recurrence could be controlled. PMID:26361699
[Pleural solitary fibrous tumor from diaphragm, being suspected of liver invasion; report of a case].
Kita, Yusuke
We report a case of solitary fibrous tumor (SFT) from diaphragmatic pleura. A 71-year-old female was admitted to our hospital because of an abnormal shadow on chest X-ray. A preoperative imaging study revealed a mass on her right diaphragm. At thoracoscopic exploration, the tumor was found to originate from diaphragm and was suspected of liver invasion. The conversion to open thoracotomy was introduced to perform appropriate surgical procedure. Pathological examination revealed proliferation of spindle cells and collagen fibers. Immuno-histochemical findings showed positive immunostaining for cell differentiation (CD) 34 and vimentin. The tumor was diagnosed as SFT with malignant potential. PMID:22485041
Respiratory muscle activity during REM sleep in patients with diaphragm paralysis.
Bennett, J R; Dunroy, H M A; Corfield, D R; Hart, N; Simonds, A K; Polkey, M I; Morrell, M J
The diaphragm is the main inspiratory muscle during REM sleep. It was hypothesized that patients with isolated bilateral diaphragm paralysis (BDP) might not be able to sustain REM sleep. Polysomnography with EMG recordings was undertaken from accessory respiratory muscles in patients with BDP and normal subjects. Patients with BDP had a normal quantity of REM sleep (mean +/- SD, 18.6 +/- 7.5% of total sleep time) achieved by inspiratory recruitment of extradiaphragmatic muscles in both tonic and phasic REM, suggesting brainstem reorganization. PMID:14718717
High-Level Pressure Support Ventilation Attenuates Ventilator-Induced Diaphragm Dysfunction in Rabbits
Ge, Huiqing; Xu, Peifeng; Zhu, Tao; Lu, Zhihua; Yuan, Yuehua; Zhou, Jiancang
Abstract: Background: The effects of different modes of mechanical ventilation in the same ventilatory support level on ventilator-induced diaphragm dysfunction onset were assessed in healthy rabbits. Methods: Twenty New Zealand rabbits were randomly assigned to 4 groups (n = 5 in each group). Group 1: no mechanical ventilation; group 2: controlled mechanical ventilation (CMV) for 24 hours; group 3: assist/control ventilation (A/C) mode for 24 hours; group 4: high-level pressure support ventilation (PSV) mode for 24 hours. Heart rate, mean arterial blood pressure, PH, partial pressure of arterial oxygen/fraction of inspired oxygen and partial pressure of arterial carbon dioxide were monitored and diaphragm electrical activity was analyzed in the 4 groups. Caspase-3 was evaluated by protein analysis and diaphragm ultra structure was assessed by electron microscopy. Results: The centroid frequency and the ratio of high frequency to low frequency were significantly reduced in the CMV, A/C and PSV groups (P < 0.001). The percent change in centroid frequency was significantly lower in the PSV group than in the CMV and A/C groups (P = 0.001 and P = 0.028, respectively). Electromyography of diaphragm integral amplitude decreased by 90% ± 1.48%, 67.8% ± 3.13% and 70.2% ± 4.72% in the CMV, A/C and PSV groups, respectively (P < 0.001). Caspase-3 protein activation was attenuated in the PSV group compared with the CMV and A/C groups (P = 0.035 and P = 0.033, respectively). Irregular swelling of mitochondria along with fractured and fuzzy cristae was observed in the CMV group, whereas mitochondrial cristae were dense and rich in the PSV group. The mitochondrial injury scores (Flameng scores) in the PSV group were the lowest among the 3 ventilatory groups (0.93 ± 0.09 in PSV versus 2.69 ± 0.05 in the CMV [P < 0.01] and PSV versus A/C groups [2.02 ± 0.08, P < 0.01]). Conclusions: The diaphragm myoelectric activity was reduced in the PSV group, although excessive oxidative
Dual-mode operation of flexible piezoelectric polymer diaphragm for intracranial pressure measurement
NASA Astrophysics Data System (ADS)
Li, Chunyan; Wu, Pei-Ming; Shutter, Lori A.; Narayan, Raj K.
The dual-mode operation of a polyvinylidene fluoride trifluoroethylene (PVDF-TrFE) piezoelectric polymer diaphragm, in a capacitive or resonant mode, is reported as a flexible intracranial pressure (ICP) sensor. The pressure sensor using a capacitive mode exhibits a higher linearity and less power consumption than resonant mode operated pressure sensor. In contrast, the latter provides better sensitivity and easier adaption for wireless application. The metrological properties of the dual-mode ICP sensor being described are satisfactory in vitro. We propose that the piezoelectric polymer diaphragm has a promising future in intracranial pressure monitoring.
A flow-transfer device with nonmetallic diaphragms for propulsion wind tunnel models
NASA Technical Reports Server (NTRS)
Capone, Francis J.; Price, Barry L.
The Langley Research Center has developed a new flow-transfer device for powered wind tunnel models in which the traditional metal bellows have been replaced with nonmetallic diaphragms. Two complete flow transfer assemblies have been fabricated and installed within a twin-jet propulsion simulation system. Calibrations of the force balance have been performed over a range of nozzle mass flow rates up to 15 lbs/sec in order to validate the nonmetallic diaphragm design concept. Results from these calibrations are compared to those obtained with flow-transfer devices utilizing metal bellows.
WE-G-18C-06: Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?
Yang, J; Cai, J; Zheng, C; Czito, B; Palta, M; Yin, F; Wang, H; Bashir, M
Purpose: To investigate whether diaphragm motion is a good surrogate for liver tumor motion by comparing their motion trajectories obtained from cine-MRI. Methods: Fourteen patients with hepatocellular carcinoma (10/14) or liver metastases (4/14) undergoing radiation therapy were included in this study. All patients underwent single-slice 2D cine-MRI simulations across the center of the tumor in three orthogonal planes. Tumor and diaphragm motion trajectories in the superior-inferior (SI), anteriorposterior (AP), and medial-lateral (ML) directions were obtained using the normalized cross-correlation based tracking technique. Agreement between tumor and diaphragm motions was assessed by calculating the phase difference percentage (PDP), intra-class correlation coefficient (ICC), Bland-Altman analysis (Diffs) and paired t-test. The distance (D) between tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between tumor and diaphragm motions. Results: Of all patients, the means (±standard deviations) of PDP were 7.1 (±1.1)%, 4.5 (±0.5)% and 17.5 (±4.5)% in the SI, AP and ML directions, respectively. The means of ICC were 0.98 (±0.02), 0.97 (±0.02), and 0.08 (±0.06) in the SI, AP and ML directions, respectively. The Diffs were 2.8 (±1.4) mm, 2.4 (±1.1) mm, and 2.2 (±0.5) mm in the SI, AP and ML directions, respectively. The p-values derived from the paired t-test were < 0.02 in SI and AP directions, whereas were > 0.58 in ML direction primarily due to the small motion in ML direction. Tumor and diaphragmatic motion had high concordance when the distance between the tumor and tracked diaphragm areas was small. Conclusion: Preliminary results showed that liver tumor motion had good correlations with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be a reliable surrogate for liver tumor motion. NIH (1R21CA165384-01A1), Golfers Against Cancer (GAC
Improving the Performance of Two-Stage Gas Guns By Adding a Diaphragm in the Pump Tube
NASA Technical Reports Server (NTRS)
Bogdanoff, D. W.; Miller, Robert J.
Herein, we study the technique of improving the gun performance by installing a diaphragm in the pump tube of the gun. A CFD study is carried out for the 0.28 in. gun in the Hypervelocity Free Flight Radiation (HFF RAD) range at the NASA Ames Research Center. The normal, full-length pump tube is studied as well as two pump tubes of reduced length (approximately 75% and approximately 33% of the normal length). Significant improvements in performance are calculated to be gained for the reduced length pump tubes upon the addition of the diaphragm. These improvements are identified as reductions in maximum pressures in the pump tube and at the projectile base of approximately 20%, while maintaining the projectile muzzle velocity or as increases in muzzle velocity of approximately 0.5 km/sec while not increasing the maximum pressures in the gun. Also, it is found that both guns with reduced pump tube length (with diaphragms) could maintain the performance of gun with the full length pump tube without diaphragms, whereas the guns with reduced pump tube lengths without diaphragms could not. A five-shot experimental investigation of the pump tube diaphragm technique is carried out for the gun with a pump tube length of 75% normal. The CFD predictions of increased muzzle velocity are borne out by the experimental data. Modest, but useful muzzle velocity increases (2.5 - 6%) are obtained upon the installation of a diaphragm, compared to a benchmark shot without a diaphragm.
Experimental investigation of circular, flat, grooved and plain steel diaphragms bursting into a 30.5-centimeter-square section
NASA Technical Reports Server (NTRS)
Yamaki, Y.; Rooker, J. R.
Limited data on the bursting of circular, initially flat, grooved and plain steel diaphragms opening into a 30.5-cm-square section are presented in tabular form. In addition, these data were used to determine values of an empirical constant to be used in a design equation for predicting diaphragm bursting pressures and opening times.
ERIC Educational Resources Information Center
Hanratty, Thomas J.
This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)
The effect of hypodynamia on the structure of the intraorganic blood vessels and the capacity of the blood stream in the diaphragm of white rats
NASA Technical Reports Server (NTRS)
Gerus, A. I.
The effect of hypodynamia on the vascular system of white rats with diaphragm deprivation was investigated. Morphological changes in the intraorganic blood stream of the diaphragm were determined. The capacity of the intraorganic vascular flow within the diaphragm muscles was established.
Thoracic meningocele in lumbo-costo-vertebral syndrome in a child: possible enlargement with repeated motion by anchoring to the diaphragm.
Wataya, Takafumi; Horikawa, Kyohei; Kitagawa, Masashi; Tashiro, Yuzuru
Lumbo-costo-vertebral syndrome (LCVS) is a rare disorder in children that is characterized by hemivertebrae, congenital absence of ribs, meningocele, and hypoplasia of the truncal and abdominal wall presenting as a congenital lumbar hernia. An otherwise healthy 12-month-old girl was referred to the authors' hospital with soft swelling on her left middle back; scoliosis had been present since birth. Imaging revealed a thoracic meningocele, ectopia of the spleen suggesting lumbar hernia, multiple anomalies of the thoracic vertebral columns, and defects of the ribs; thus, LCVS was diagnosed. Surgical observation revealed that the meningocele was firmly anchored to part of the diaphragm, which created stretching tension in the meningocele continuously with exhalation. Once detached, the meningocele shrank spontaneously and never developed again after cauterization. In this case, continuous or pulsatile pressure in the presence of a vertebral defect was thus considered to be an important factor for formation of the thoracic meningocele. PMID:27058456
The JAK–STAT Pathway Is Critical in Ventilator-Induced Diaphragm Dysfunction
Tang, Huibin; Smith, Ira J; Hussain, Sabah NA; Goldberg, Peter; Lee, Myung; Sugiarto, Sista; Godinez, Guillermo L; Singh, Baljit K; Payan, Donald G; Rando, Thomas A; Kinsella, Todd M; Shrager, Joseph B
Mechanical ventilation (MV) is one of the lynchpins of modern intensive-care medicine and is life saving in many critically ill patients. Continuous ventilator support, however, results in ventilation-induced diaphragm dysfunction (VIDD) that likely prolongs patients' need for MV and thereby leads to major associated complications and avoidable intensive care unit (ICU) deaths. Oxidative stress is a key pathogenic event in the development of VIDD, but its regulation remains largely undefined. We report here that the JAK–STAT pathway is activated in MV in the human diaphragm, as evidenced by significantly increased phosphorylation of JAK and STAT. Blockage of the JAK–STAT pathway by a JAK inhibitor in a rat MV model prevents diaphragm muscle contractile dysfunction (by ~85%, p < 0.01). We further demonstrate that activated STAT3 compromises mitochondrial function and induces oxidative stress in vivo, and, interestingly, that oxidative stress also activates JAK–STAT. Inhibition of JAK–STAT prevents oxidative stress-induced protein oxidation and polyubiquitination and recovers mitochondrial function in cultured muscle cells. Therefore, in ventilated diaphragm muscle, activation of JAK–STAT is critical in regulating oxidative stress and is thereby central to the downstream pathogenesis of clinical VIDD. These findings establish the molecular basis for the therapeutic promise of JAK–STAT inhibitors in ventilated ICU patients. PMID:25286450
[Recent injuries to the left diaphragm: value of laparoscopy in Africa and Europe].
Savoie, P H; Bonnet, P M; Avaro, J P; Peycru, T; Bertani, A; Farthouat, P
Management of recent diaphragm injury is challenging. The purpose of this report is to describe two patients who presented injuries to the left diaphrgmatic cupola, i.e., rupture due to blunt trauma in Europe and a stab wound in Africa. The value of laparoscopy for diagnosis and treatment are discussed in these contrasting settings. PMID:19068989
Mitochondrial function in diaphragm of emphysematous hamsters after treatment with nandrolone
Wijnhoven, Hanneke JH; Ennen, Leo; Rodenburg, Richard JT; Dekhuijzen, PN Richard
Respiratory failure in patients with COPD may be caused by insufficient force production or insufficient endurance capacity of the respiratory muscles. Anabolic steroids may improve respiratory muscle function in COPD. The effect of anabolic steroids on mitochondrial function in the diaphragm in emphysema is unknown. In an emphysematous male hamster model, we investigated whether administration of the anabolic steroid nandrolone decanoate (ND) altered the activity of mitochondrial respiratory chain complexes in the diaphragm. The bodyweight of hamsters treated with ND was decreased after treatment compared with initial values, and serum testosterone levels were significantly lower in hamsters treated with ND than in control hamsters. No difference in the activity of mitochondrial respiratory chain complexes in the diaphragm between normal and emphysematous hamsters was observed. Treatment with ND did not change the activity of mitochondrial respiratory chain complexes in the diaphragm of both normal and emphysematous hamsters. In emphysematous hamsters, administration of ND decreased the activity of succinate:cytochrome c oxidoreductase compared with ND treatment in normal hamsters. We conclude that anabolic steroids have negative effects on the activity of succinate:cytochrome c oxidoreductase and anabolic status in this emphysematous hamster model. PMID:18046906
[INVITED] A miniaturized optical fiber microphone with concentric nanorings grating and microsprings structured diaphragm
NASA Astrophysics Data System (ADS)
Wang, Hui; Xie, Zhenwei; Zhang, Mile; Cui, Hailin; He, Jingsuo; Feng, Shengfei; Wang, Xinke; Sun, Wenfeng; Ye, Jiasheng; Han, Peng; Zhang, Yan
A miniaturized optical fiber microphone (OFM) is created by fabricating a concentric nanorings grating and microsprings structured half spherical diaphragm on the end facet of a single-mode fiber (SMF). The diaphragm is fabricated via the method of two-photon 3D lithography. The thin nanorings grating patterned diaphragm is actually a resonant grating-waveguide. It exhibits high reflectivity when resonance is excited. A microlens is fabricated at the core of the fiber, which is used to diverge the output light to make it be normally incident onto the diaphragm, then reflected back to the fiber. The intensities of the reflected back light will be changed if the resonant conditions of the resonant grating-waveguide are broken due to the sound pressure induced geometrical changes of the configuration. This makes such device be an acoustic sensor. The microsprings are designed to improve the sensitivity to the sound pressure. Acoustic inspections show that this OFM can detect the weak sound in air with frequency band from 400 to 2000 Hz.
Studies on neuromuscular blockade by boldine in the mouse phrenic nerve-diaphragm.
Kang, J J; Cheng, Y W; Fu, W M
The effects of boldine [(S)-2,9-dihydroxyl-1,10-dimethoxy-aporphine], a major alkaloid in the leaves and bark of Boldo (Peumus boldus Mol.), on neuromuscular transmission were studied using a muscle phrenic-nerve diaphragm preparation. Boldine at concentrations lower than 200 microM preferentially inhibited, after an initial period of twitch augmentation, the nerve-evoked twitches of the mouse diaphragm and left the muscle-evoked twitches unaffected. The twitch inhibition could be restored by neostigmine or washout with Krebs solution. The twitches evoked indirectly and directly were both augmented initially, suggesting that the twitch augmentation induced by boldine was myogenic. Boldine inhibited the acetylcholine-induced contraction of denervated diaphragm dose-dependently with an IC50 value of 13.5 microM. At 50 microM, boldine specifically inhibited the amplitude of the miniature end plate potential. In addition, boldine was similar to d-tubocurarine in its action to reverse the neuromuscular blocking action of alpha-bungarotoxin. These results showed that the neuromuscular blockade by boldine on isolated mouse phrenic-nerve diaphragm might be due to its direct interaction with the postsynaptic nicotinic acetylcholine receptor. PMID:9541284
Influence of space flight factors on the ultrastructure of rat diaphragm muscle.
Babakova, L L; Baranov, V M; Pozdnyakov, O M
Analysis of ultrastructural changes in diaphragm muscle and synaptic apparatus after 7- and 14-day biosatellite spaceflight showed destructive and atrophic changes that developed starting from in the early terms of exposure. Structural alterations of different severity were revealed in all elements of the muscle (muscle fibers, neuromuscular junctions, intramuscular nerves, and blood vessels) and were paralleled by activation of regeneration processes. PMID:23667862
CFD Fuel Slosh Modeling of Fluid-Structure Interaction in Spacecraft Propellant Tanks with Diaphragms
NASA Technical Reports Server (NTRS)
Sances, Dillon J.; Gangadharan, Sathya N.; Sudermann, James E.; Marsell, Brandon
Liquid sloshing within spacecraft propellant tanks causes rapid energy dissipation at resonant modes, which can result in attitude destabilization of the vehicle. Identifying resonant slosh modes currently requires experimental testing and mechanical pendulum analogs to characterize the slosh dynamics. Computational Fluid Dynamics (CFD) techniques have recently been validated as an effective tool for simulating fuel slosh within free-surface propellant tanks. Propellant tanks often incorporate an internal flexible diaphragm to separate ullage and propellant which increases modeling complexity. A coupled fluid-structure CFD model is required to capture the damping effects of a flexible diaphragm on the propellant. ANSYS multidisciplinary engineering software employs a coupled solver for analyzing two-way Fluid Structure Interaction (FSI) cases such as the diaphragm propellant tank system. Slosh models generated by ANSYS software are validated by experimental lateral slosh test results. Accurate data correlation would produce an innovative technique for modeling fuel slosh within diaphragm tanks and provide an accurate and efficient tool for identifying resonant modes and the slosh dynamic response.
Diaphragm dome surface segmentation in CT data sets: a 3D active appearance model approach
NASA Astrophysics Data System (ADS)
Beichel, Reinhard; Gotschuli, Georg; Sorantin, Erich; Leberl, Franz W.; Sonka, Milan
Knowledge about the location of the diaphragm dome surface, which separates the lungs and the heart from the abdominal cavity, is of vital importance for applications like automated segmentation of adjacent organs (e.g., liver) or functional analysis of the respiratory cycle. We present a new 3D Active Appearance Model (AAM) approach to segmentation of the top layer of the diaphragm dome. The 3D AAM consists of three parts: a 2D closed curve (reference curve), an elevation image and texture layers. The first two parts combined represent 3D shape information and the third part image intensity of the diaphragm dome and the surrounding layers. Differences in height between dome voxels and a reference plane are stored in the elevation image. The reference curve is generated by a parallel projection of the diaphragm dome outline in the axial direction. Landmark point placement is only done on the (2D) reference curve, which can be seen as the bounding curve of the elevation image. Matching is based on a gradient-descent optimization process and uses image intensity appearance around the actual dome shape. Results achieved in 60 computer generated phantom data sets show a high degree of accuracy (positioning error -0.07+/-1.29 mm). Validation using real CT data sets yielded a positioning error of -0.16+/-2.95 mm. Additional training and testing on in-vivo CT image data is ongoing.
[Effect of dietary protein on the function and morphology of diaphragm in rats with experimental emphysema].
Zhao, Y; Shen, L
The effects of dietary protein on the function and morphology of diaphragm of rats with emphysema were observed in 50 SD rats, 10 rats in each group. The emphysema in groups E(emphysema control), HP(emphysema with high protein diet) and LP(emphysema with low protein diet) was induced by intra-tracheal instillation of elastase (750 U/kg BW). The control rat (C1, C2) were instilled with normal saline. After 6 weeks of experiment, the total lung volume and the average area of alveolus was significantly increased in the group E compared with group C1 (P < 0.05) and the number of alveolus per unit area was also reduced obviously (P < 0.05). The average contractile force of diaphragm at a stimulus rate of 20 Hz expressed as a ratio of the maximal contractile force (F20/Fmax) was increased significantly in group E compared with group C (P < 0.01). The cross-sectional area of slow-twitch fibers increased significantly in group E. After 10 weeks of oral supplementation with 24% casein(HP) or 8% casein (LP) to the rats with emphysema, the contractility of the diaphragm in group LP was lower than that in the control group and the HP group. It was concluded that high protein diet might be beneficial to maintain the function of diaphragm in patients with emphysema. PMID:12561617
Selected Contribution: Improved anoxic tolerance in rat diaphragm following intermittent hypoxia.
Clanton, T L; Wright, V P; Reiser, P J; Klawitter, P F; Prabhakar, N R
Intermittent hypoxia (IH), associated with obstructive sleep apnea, initiates adaptive physiological responses in a variety of organs. Little is known about its influence on diaphragm. IH was simulated by exposing rats to alternating 15-s cycles of 5% O2 and 21% O2 for 5 min, 9 sets/h, 8 h/day, for 10 days. Controls did not experience IH. Diaphragms were excised 20-36 h after IH. Diaphragm bundles were studied in vitro or analyzed for myosin heavy chain isoform composition. No differences in maximum tetanic stress were observed between groups. However, peak twitch stress (P < 0.005), twitch half-relaxation time (P < 0.02), and tetanic stress at 20 or 30 Hz (P < 0.05) were elevated in IH. No differences in expression of myosin heavy chain isoforms or susceptibility to fatigue were seen. Contractile function after 30 min of anoxia (95% N2-5% CO2) was markedly preserved at all stimulation frequencies during IH and at low frequencies after 15 min of reoxygenation. Anoxia-induced increases in passive muscle force were eliminated in the IH animals (P < 0.01). These results demonstrate that IH induces adaptive responses in the diaphragm that preserve its function in anoxia. PMID:11356820
Comparison of solar powered water pumping systems which use diaphragm pumps
Technology Transfer Automated Retrieval System (TEKTRAN)
Four solar photovoltaic (PV) powered diaphragm pumps were tested at different simulated pumping depths at the USDA-ARS Conservation and Production Research Laboratory near Bushland, Texas. Two of the pumps were designed for intermediate pumping depths (30 to 70 meters), and the other two pumps were...
75 FR 54152 - Determination of Regulatory Review Period for Purposes of Patent Extension; NEURX DIAPHRAGM...
Federal Register 2010, 2011, 2012, 2013, 2014
... Trademarks, Department of Commerce, for the extension of a patent which claims that medical device. ADDRESSES... dated February 17, 2010, FDA advised the Patent and Trademark Office that this medical device had... Patent Extension; NEURX DIAPHRAGM PACING SYSTEM AGENCY: Food and Drug Administration, HHS. ACTION:...
Effects of diaphragm respiration exercise on pulmonary function of male smokers in their twenties.
Seo, KyoChul; Park, Seung Hwan; Park, KwangYong
[Purpose] We investigated how diaphragm respiration exercises can affect pulmonary function in long-term male smokers in their twenties. [Subjects and Methods] Twenty-eight healthy males between 20 and 29 years of age were randomly divided into an experimental and a control group (14 members each). The experiment was conducted during 30 min sessions, 3 times a week for 4 weeks. The experimental group performed diaphragm respiration exercises and the control group performed exercises using MOTOmed. Pulmonary function (tidal volume, breathing capacity, inspiratory reserve volume, inspiratory capacity, and expiratory reserve volume) was evaluated and analyzed before and after the experiment. [Results] Our results revealed significant increases in tidal volume, inspiratory reserve volume, inspiratory capacity, and breathing capacity in the experimental group. These increases were greater in the experimental group than in the control group. [Conclusion] In our study, the experimental group which performed diaphragm respiration exercises showed a greater improvement in pulmonary function compared with the control group. It is hypothesized that greater improvement in pulmonary function is expected if diaphragm respiration exercises are implemented taking into account the age of the smokers. PMID:26311972
Vanadium diaphragm electrode serves as hydrogen diffuser in lithium hydride cell
NASA Technical Reports Server (NTRS)
Crouthamel, C. E.; Heinrich, R. R.; Johnson, C. E.
Lithium hydride cell uses vanadium diaphragm electrode as a hydrogen diffuser. Vanadium is high in hydrogen gas solubility and permeability, is least sensitive to adverse surface effects, maintains good mechanical strength in hydrogen atmospheres, and appears to be compatible with all alkali-halide electrolytes and lithium metals.
Analysis and Development of a Quick Acting Diaphragm-less Shock Tube Driver
NASA Astrophysics Data System (ADS)
Portaro, Rocco; Ng, Hoi Dick
This work discusses the construction and performance characteristics of a diaphragmless shock tube driver. Shock waves play integral roles in many industrial, medical and scientific environments, consequently it is important to observe the behaviour of these waves and how they interact with their surroundings. The diaphragmless shock tube provides a quick and effective means of producing shock waves in gases. The major advantages compared to conventional diaphragms include, minimal downtime between repeated experiments, opening times comparable to those of conventional diaphragms and infinitely adjustable opening pressure without the use of various diaphragm thicknesses. Moreover, the diaphragmless design also eliminates fragments that are carried downstream of the shock tube once the conventional diaphragm is ruptured. The design utilized in this work is built on that of Downey et al. [M.S. Downey, T.J. Cloete, A.D.B.Yates, Shock Waves 21(4): 315-319, 2011] and is improved in order to obtain faster opening times leading to stronger shock formation. Furthermore in depth numerical analysis using the commercial CFD package Fluent is carried out to validate experimental data for driven pressures and opening times as a function of driver pressure. Supported by Fonds de recherche du Quebec - Nature et technologies.
Designing acoustic-electric strain-gauge converters for sensitive diaphragm elements
NASA Astrophysics Data System (ADS)
Chernyak, M. G.; Kovalenko, T. V.
Analytic expressions and nomograms are obtained to estimate the sensitivity of differential acoustic-electric measuring pressure converter with an error no more than 5% and to choose such an arrangement of strain-gauge converters on its sensitive diaphragm element that would ensure an additive temperature error of the measuring pressure converter less than 10-4 K-1
Where Did the Water Go?: Boyle's Law and Pressurized Diaphragm Water Tanks
ERIC Educational Resources Information Center
Brimhall, James; Naga, Sundar
Many homes use pressurized diaphragm tanks for storage of water pumped from an underground well. These tanks are very carefully constructed to have separate internal chambers for the storage of water and for the air that provides the pressure. One might expect that the amount of water available for use from, for example, a 50-gallon tank would be…
Blunt traumatic rupture of the right ventricle, with intrapericardial rupture of the diaphragm: successful surgical repair.
Le Treut, Y P; Herve, L; Cardon, J M; Boutboul, R; Bricot, R
The authors report a case of chest injury causing rupture of the right ventricle and diaphragm, discovered during laparotomy for haemoperitoneum. This type of injury to the heart has rarely been cited in the literature since survival rates are low and the diagnosis often overlooked. PMID:7319634
Diaphragm structure and function in the Florida manatee (Trichechus manatus latirostris).
Rommel, S; Reynolds, J E
Relative to many other mammals, little is known about the functional morphology of the four extant species of the order Sirenia. In this study, 166 Florida manatee (Trichechus manatus latirostris) carcasses fresh enough to collect detailed anatomical information were examined to describe the gross anatomy of the diaphragm. Our results show that the Florida manatee's diaphragm differs from those of other mammals in that it: lies in a dorsal plane, rather than in the more typical transverse plane; is located dorsal to the heart and does not attach to the sternum; and attaches medially at the "I"-shaped central tendon to bony projections extending ventrally from the vertebral bodies, forming two distinct hemidiaphragms. The manatee's transverse septum is a separate structure that lies at a right angle to the diaphragm and separates the heart from the liver and other viscera. The extreme muscularity of the diaphragm and the ability of manatees to adjust their position in the water column with minimal external movement suggest that diaphragmatic contractions may change the volume of each pleural cavity to affect buoyancy, roll, and pitch. We also hypothesize that such contractions, in concert with contractions of powerful abdominal muscles, may compress gas in the massive large intestine, and thereby also contribute to buoyancy control. PMID:10760742
Effects of diaphragm respiration exercise on pulmonary function of male smokers in their twenties
Seo, KyoChul; Park, Seung Hwan; Park, KwangYong
[Purpose] We investigated how diaphragm respiration exercises can affect pulmonary function in long-term male smokers in their twenties. [Subjects and Methods] Twenty-eight healthy males between 20 and 29 years of age were randomly divided into an experimental and a control group (14 members each). The experiment was conducted during 30 min sessions, 3 times a week for 4 weeks. The experimental group performed diaphragm respiration exercises and the control group performed exercises using MOTOmed. Pulmonary function (tidal volume, breathing capacity, inspiratory reserve volume, inspiratory capacity, and expiratory reserve volume) was evaluated and analyzed before and after the experiment. [Results] Our results revealed significant increases in tidal volume, inspiratory reserve volume, inspiratory capacity, and breathing capacity in the experimental group. These increases were greater in the experimental group than in the control group. [Conclusion] In our study, the experimental group which performed diaphragm respiration exercises showed a greater improvement in pulmonary function compared with the control group. It is hypothesized that greater improvement in pulmonary function is expected if diaphragm respiration exercises are implemented taking into account the age of the smokers. PMID:26311972
Physiological properties of human diaphragm muscle fibres and the effect of chronic obstructive pulmonary disease
Stubbings, Alison K; Moore, Alastair J; Dusmet, Michael; Goldstraw, Peter; West, Timothy G; Polkey, Michael I; Ferenczi, Michael A
The contractile and actomyosin ATPase properties of single fibres were examined in human diaphragm muscle obtained from patients with and without chronic obstructive pulmonary disease (COPD). Costal diaphragm biopsies were taken from five patients without evidence of COPD and from 11 age-matched individuals with varying degrees of the disease. Our aim was to establish whether changes in contractile properties of COPD diaphragm could be fully explained by the previously documented shift towards a greater proportion of type I myosin heavy chain isoform in COPD. The relative proportion of type I diaphragm fibres from non-COPD and COPD patients was measured by gel electrophoresis, and was negatively correlated with FEV1 over the full range of values investigated. There was also significant atrophy of the type I fibre population in COPD diaphragms. Isometric tension was similar among the fibre types and between the COPD and non-COPD patients. The intrinsic energetic properties of diaphragm fibres were examined by monitoring the time-resolved actomyosin ATPase activity in COPD and non-COPD fibres that produced similar isometric forces. The isometric ATPase rate in COPD fibres was reduced to 50% of the rate in non-COPD fibres; hence, the cost of isometric contraction in type I and type IIA COPD fibres was reduced to between one-third and one-half of the tension cost calculated for non-COPD fibres. The rate of force development in type I COPD fibres was reduced to 50% of the rate seen in non-COPD type-I fibres. No difference in the rate of ATP consumption between COPD and non-COPD fibres was evident during isovelocity shortening. These data extend previous findings showing that aspects of breathing mechanics during progressive COPD are associated with remodelling of the diaphragm fibre-type distribution; on top of the increase in type I fibres there are fibre-specific reductions in force development rate (type I fibres) and ATPase rate that are consistent with the
Hydrogel based sensor arrays (2 × 2) with perforated piezoresistive diaphragms for metabolic monitoring (in vitro)
Orthner, M.P.; Lin, G.; Avula, M.; Buetefisch, S.; Magda, J.; Rieth, L.W.; Solzbacher, F.
This report details the first experimental results from novel hydrogel sensor array (2 × 2) which incorporates analyte diffusion pores into a piezoresistive diaphragm for the detection of hydrogel swelling pressures and hence chemical concentrations. The sensor assembly was comprised of three components, the active four sensors, HPMA/DMA/TEGDMA (hydroxypropyl methacrylate (HPMA), N,N-dimethylaminoethyl methacrylate (DMA) and crosslinker tetra-ethyleneglycol dimethacrylate (TEGDMA)) hydrogel, and backing plate. Each of the individual sensors of the array can be used with various hydrogels used to measure the presence of a number of stimuli including pH, ionic strength, and glucose concentrations. Ideally, in the future, these sensors will be used for continuous metabolic monitoring applications and implanted subcutaneously. In this paper and to properly characterize the sensor assembly, hydrogels sensitive to changes ionic strength were synthesized using hydroxypropyl methacrylate (HPMA), N,N-dimethylaminoethyl methacrylate (DMA) and crosslinker tetra-ethyleneglycol dimethacrylate (TEGDMA) and inserted into the sensor assembly. This hydrogel quickly and reversibly swells when placed environments of physiological buffer solutions (PBS) with ionic strengths ranging from 0.025 to 0.15 M, making it ideal for proof-of-concept testing and initial characterization. The assembly was wire bonded to a printed circuit board and coated with 3 ± 0.5 μm of Parylene-C using chemical vapor deposition (CVD) to protect the sensor and electrical connections during ionic strength wet testing. Two versions of sensors were fabricated for comparison, the first incorporated diffusion pores into the diaphragm, and the second used a solid diaphragm with perforated backing plate. This new design (perforated diaphragm) was shown to have slightly higher sensitivity than solid diaphragm sensors with separate diffuse backing plates when coupled with the hydrogel. The sensitivities for the 1 mm
Expression of superoxide dismutase and matrix metalloproteinase type 2 in diaphragm muscles of young rats.
Carmeli, E; Maor, M; Kodesh, E
Moderate physical activity increases antioxidant defenses, whereas intensive activity is associated with oxidative stress. In this study we investigated the expression of superoxide dismutase (Cu,Zn-SOD), a major antioxidant defense enzyme, and that of the proteolytic enzyme matrix metalloproteinase-2 (MMP-2) in exercising muscle tissue. Treadmill running was used as a model to investigate the mechanism involved in muscle use and over use. Sprague-Dawley female rats (4 months old) were randomly assigned to 3 groups: running group I, trained at a slow speed (18 m/min; approximately 50% VO(2)), running group II, trained at a very fast speed (32 m/min; approximately 75% VO(2)), for 3 weeks, and group III - control, non-running group. Cu,Zn-SOD was measured spectrophotometrically at 320 nm by assessing the inhibition of cytochrome c reduction by xanthine oxidase. MMP-2 levels of protein and mRNA were assessed in the diaphragm by Western blotting and by reverse transcriptase-polymerase chain reaction, respectively. We found that Cu,Zn-SOD level significantly decreased in the crural diaphragm muscle of rats three weeks after fast speed running, whereas it remained unchanged in the sternal diaphragm muscle three weeks after slow speed running. The expression of MMP-2 increased in both fast and slow running groups; however, it was particularly prominent in the fast twitch muscle fibers type IIb. We conclude that the crural diaphragm muscle, which contains significantly more type IIb fibers, was more affected following fast speed running than the sternal/costal diaphragm muscles, which have an equal distribution of slow twitch (type I) and fast twitch (type IIb) muscle fibers. PMID:20134035
Assessment of neonatal diaphragm function using magnetic stimulation of the phrenic nerves.
Rafferty, G F; Greenough, A; Dimitriou, G; Kavadia, V; Laubscher, B; Polkey, M I; Harris, M L; Moxham, J
A nonvolitional test to assess diaphragm strength in neonates has not been previously described. Our aim was to assess the feasibility of cervical (CMS) and anterior (AMS) magnetic stimulation of the phrenic nerves in neonates. Double circular stimulating coils (90-mm) were used. For CMS, one coil was placed over the cervical spine to bilaterally stimulate the phrenic nerve roots, whereas for AMS the coils were placed on the anterolateral aspect of the neck to allow unilateral and bilateral stimulation. Diaphragm contractility was assessed as transdiaphragmatic pressure (Pdi) measured with balloon catheters positioned in the midesophagus and stomach. Stimulus supramaximality was assessed by examining diaphragm twitch Pdi (TwPdi) across a range of stimulator outputs; 85, 90, 95, and 100% of maximum. Pressure signals were measured by differential pressure transducer and displayed in real time on a computer. Patients were studied supine during sleep. CMS was performed on seven neonates (mean gestational age [GA] 38 wk, range 33 to 40 wk) and AMS on 18 neonates (mean GA 37 wk, range 32 to 41 wk). The mean (SD) TwPdi with CMS was 2.5 (0.8) cm H(2)O. CMS was not supramaximal; reducing the stimulator output below 100% caused marked reductions in TwPdi, also the shape of the pressure waveforms suggested that CMS may not have activated the diaphragm alone. Mean (SD) TwPdi with AMS was 4.5 (1.3) cm H(2)O on the left, 4.1 (0.9) cm H(2)O on the right, and 8.7 (3.9) cm H(2)O for bilateral stimulation. The shape of the pressure waveforms suggested that AMS was more specific and a plateau in TwPdi at higher stimulator outputs indicated supramaximality. We conclude that AMS may provide a useful technique to assess diaphragm function in the neonate. PMID:11112160
Sleep-disordered breathing in unilateral diaphragm paralysis or severe weakness.
Steier, J; Jolley, C J; Seymour, J; Kaul, S; Luo, Y M; Rafferty, G F; Hart, N; Polkey, M I; Moxham, J
Few data exist concerning sleep in patients with hemidiaphragm paralysis or weakness. Traditionally, such patients are considered to sustain normal ventilation in sleep. In the present study, diaphragm strength was measured in order to identify patients with unilateral paralysis or severe weakness. Patients underwent polysomnography with additional recordings of the transoesophageal electromyogram (EMG) of the diaphragm and surface EMG of extra-diaphragmatic respiratory muscles. These data were compared with 11 normal, healthy subjects matched for sex, age and body mass index (BMI). In total, 11 patients (six males, mean+/-sd age 56.5+/-10.0 yrs, BMI 28.7+/-2.8 kg x m(-2)) with hemidiaphragm paralysis or severe weakness (unilateral twitch transdiaphragmatic pressure 3.3+/-1.7 cmH(2)O (0.33+/-0.17 kPa) were studied. They had a mean+/-sd respiratory disturbance index of 8.1+/-10.1 events x h(-1) during non-rapid eye movement (NREM) sleep and 26.0+/-17.8 events x h(-1) during rapid eye movement (REM) sleep (control groups 0.4+/-0.4 and 0.7+/-0.9 events x h(-1), respectively). The diaphragm EMG, as a percentage of maximum, was double that of the control group in NREM sleep (15.3+/-5.3 versus 8.9+/-4.9% max, respectively) and increased in REM sleep (20.0+/-6.9% max), while normal subjects sustained the same level of activation (6.2+/-3.1% max). Patients with unilateral diaphragm dysfunction are at risk of developing sleep-disordered breathing during rapid eye movement sleep. The diaphragm electromyogram, reflecting neural respiratory drive, is doubled in patients compared with normal subjects, and increases further in rapid eye movement sleep. PMID:18684853
Cost-Effectiveness of Introducing the SILCS Diaphragm in South Africa
Lépine, Aurélia; Nundy, Neeti; Kilbourne-Brook, Maggie; Siapka, Mariana; Terris-Prestholt, Fern
Background Though South Africa has high contraceptive use, unintended pregnancies are still widespread. The SILCS diaphragm could reduce the number of women with unmet need by introducing a discreet, woman-initiated, non-hormonal barrier method to the contraceptive method mix. Methods A decision model was built to estimate the impact and cost-effectiveness of the introduction of the SILCS diaphragm in Gauteng among women with unmet need for contraception in terms of unintended and mistimed pregnancies averted, assuming that the available contraceptives on the market were not a satisfying option for those women. Full costs were estimated both from a provider's and user's perspective, which also accounts for women's travel and opportunity cost of time, assuming a 5% uptake among women with unmet contraceptive need. The incremental cost-effectiveness ratio is computed at five and 10 years after introduction to allow for a distribution of fixed costs over time. A probabilistic sensitivity analysis was conducted to incorporate decision uncertainty. Results The introduction of the SILCS diaphragm in Gauteng could prevent an estimated 8,365 unintended pregnancies and 2,117 abortions over five years, at an annual estimated cost of US$55 per woman. This comes to a cost per pregnancy averted of US$153 and US$171 from a user's and provider's perspectives, respectively, with slightly lower unit costs at 10 years. Major cost drivers will be the price of the SILCS diaphragm and the contraceptive gel, given their large contribution to total costs (around 60%). Conclusions The introduction of the SILCS diaphragm in the public sector is likely to provide protection for some women for whom current contraceptive technologies are not an option. However to realize its potential, targeting will be needed to reach women with unmet need and those with likely high adherence. Further analyses are needed among potential users to optimize the introduction strategy. PMID:26295955
NASA Technical Reports Server (NTRS)
This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)
An experimental evaluation of metallic diaphragms for positive fuel expulsion in the Atmosphere Explorer, hydrazine propulsion subsystem
NASA Technical Reports Server (NTRS)
Woodruff, W. L.
Four Arde conospheroid metallic diaphragms were tested at NASA to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Atmosphere Explorer spacecraft (AE's C, D, and E). The diaphragms will be used for positive propellant expulsion and spacecraft center of mass (c.m.) control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 10 psid during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft c.m. control, the diaphragm must not be reversed prior to flight.
Fabrication of polyimide bi-stable diaphragms using oxide compressive stresses for the field of 'Buckle MEMS'
NASA Astrophysics Data System (ADS)
Gowrishetty, Usha R.; Walsh, Kevin M.; Berfield, Thomas A.
In this paper we develop vacuum-actuated polyimide bi-stable actuators using buckled diaphragms for applications in the field of MEMS. The fabrication process involves a single mask step and DRIE etch step to fabricate the buckled bi-stable diaphragms. Compressive stresses in a companion thermal oxide layer provide pre-stress in the polyimide mechanical films that initiates diaphragm buckling upon release. Pressure was used to actuate these polyimide diaphragms from their first stable state to their second stable state, resulting in 'zero electrical power' actuation. The buckling height of the polyimide diaphragms is approximately 7.6 µm with an actuation pressure of 41 kPa, which compares favorably with model predictions assuming effective diaphragm properties for a single layer. These polyimide diaphragms can be used as the fundamental building blocks in micro-pumps, micro-valves, switches and optical devices. Because of their bi-stable nature, they can also be used for applications in mechanical memory storage.
Modeling and analysis of a novel combined peninsula-island structure diaphragm for ultra-low pressure sensing with high sensitivity
NASA Astrophysics Data System (ADS)
Xu, Tingzhong; Zhao, Libo; Jiang, Zhuangde; Xu, Yu; Zhao, Yulong
A novel combined peninsula-island structure diaphragm has been developed with four pairs of peninsula and island structures as well as four gaps between them. When a pressure is applied to the diaphragm, the major strain energy of the diaphragm is locked in the position above each gap, which is called the stress concentration region (SCR). Also, minimal strain energy is wasted outside the SCR. Therefore, this novel diaphragm is favorable in obtaining high sensitivity for a micro-electromechanical system piezoresistive ultra-low pressure sensor. In order to optimize the diaphragm structure, the partial differential equation governing the diaphragm deflection has been given under pressure. The theoretical analysis solutions are obtained based on the theory of the Navier trigonometric series and the mirror image method, and in accordance with the finite element method simulation results. Finally, a sensor with the proposed diaphragm is designed with the working range of 0-500 Pa and has sensitivity above 0.055 mV V-1 Pa-1. In comparison to a flat diaphragm with the same dimensions, this novel diaphragm achieves a sensitivity level increased by 256%, a nonlinearity reduced by 79%, and a resonance frequency increased by 5.5%. In addition, the proposed theoretical analysis solution of the diaphragm can also be applied to other kinds of diaphragm with different islands to achieve optimization.
NASA Technical Reports Server (NTRS)
The attractive wall covering shown below is one of 132 styles in the Mirror Magic II line offered by The General Tire & Rubber Company, Akron, Ohio. The material is metallized plastic fabric, a spinoff from space programs. Wall coverings are one of many consumer applications of aluminized plastic film technology developed for NASA by a firm later bought by King-Seeley Thermos Company, Winchester, Massachusetts, which now produces the material. The original NASA use was in the Echo 1 passive communications satellite, a "space baloon" made of aluminized mylar; the high reflectivity of the metallized coating enabled relay of communications signals from one Earth station to another by "bouncing" them off the satellite. The reflectivity feature also made the material an extremely efficient insulator and it was subsequently widely used in the Apollo program for such purposes as temperature control of spacecraft components and insulation of tanks for fuels that must be maintained at very low temperatures. I Used as a wall covering, the aluminized material offers extra insulation, reflects light and I resists cracking. In addition to General Tire, King-Seeley also supplies wall covering material to Columbus Coated Fabrics Division of Borden, Incorporated, Columbus, Ohio, among others.
ERIC Educational Resources Information Center
McGinley, Connie Q.
The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…
Overexpression of antioxidant enzymes in diaphragm muscle does not alter contraction-induced fatigue or recovery.
McClung, Joseph M; Deruisseau, Keith C; Whidden, Melissa A; Van Remmen, Holly; Richardson, Arlan; Song, Wook; Vrabas, Ioannis S; Powers, Scott K
Low levels of reactive oxygen species (ROS) production are necessary to optimize muscle force production in unfatigued muscle. In contrast, sustained high levels of ROS production have been linked to impaired muscle force production and contraction-induced skeletal muscle fatigue. Using genetically engineered mice, we tested the hypothesis that the independent transgenic overexpression of catalase (CAT), copper/zinc superoxide dismutase (CuZnSOD; SOD1) or manganese superoxide dismutase (MnSOD; SOD2) antioxidant enzymes would negatively affect force production in unfatigued diaphragm muscle but would delay the development of muscle fatigue and enhance force recovery after fatiguing contractions. Diaphragm muscle from wild-type littermates (WT) and from CAT, SOD1 and SOD2 overexpressing mice were subjected to an in vitro contractile protocol to investigate the force-frequency characteristics, the fatigue properties and the time course of recovery from fatigue. The CAT, SOD1 and SOD2 overexpressors produced less specific force (in N cm(-2)) at stimulation frequencies of 20-300 Hz and produced lower maximal tetanic force than WT littermates. The relative development of muscle fatigue and recovery from fatigue were not influenced by transgenic overexpression of any antioxidant enzyme. Morphologically, the mean cross-sectional area (in microm(2)) of diaphragm myofibres expressing myosin heavy chain type IIA was decreased in both CAT and SOD2 transgenic animals, and the percentage of non-contractile tissue increased in diaphragms from all transgenic mice. In conclusion, our results do not support the hypothesis that overexpression of independent antioxidant enzymes protects diaphragm muscle from contraction-induced fatigue or improves recovery from fatigue. Moreover, our data are consistent with the concept that a basal level of ROS is important to optimize muscle force production, since transgenic overexpression of major cellular antioxidants is associated with
Dynamic Strain on Thin Diaphragms of a Mercury Target During 800-MeV Proton Thermal Shock Tests
Allison, S.W.; Andriulli, J.B.; Cates, M.R.; Earl, D.D.; Haines, J.R.; Morrissey, F.X.; Tsai, C.C.; Wender, S.
Extrinsic Fabry-Perot Interferometric fiber optic sensors were used to measure dynamic strains on thin diaphragms of a liquid mercury target, which was subjected to intense 800-MeV proton thermal shock tests. The mercury target is engineered with very thin end plates or diaphragms (either 0.6 mm or 1.9 mm) for studying large strain effects. During thermal shock tests, the mercury in the target interacted with an intense pulsed beam of 2.4x10{sup 13 protons}. The resulting pressure waves lead to large strains exceeding 250 microstrains on a 0.6-mm diaphragm. Significant factors relative to the accuracy of strain measurements are emphasized, such as the sensor air gap, alignment of sensors, and frequency response of the strain instrument. In this paper, dynamic strains measured on thin diaphragms are described and discussed.
Sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure measurement.
Liao, Changrui; Liu, Shen; Xu, Lei; Wang, Chao; Wang, Yiping; Li, Zhengyong; Wang, Qiao; Wang, D N
We demonstrate a sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure sensing applications. The thinnest silica diaphragm, with a thickness of ∼320 nm, has been achieved by use of an improved electrical arc discharge technique. Such a sub-micron silica diaphragm breaks the sensitivity limitation imposed by traditional all-silica Fabry-Perot interferometric pressure sensors and, as a result, a high pressure sensitivity of ∼1036 pm/MPa at 1550 nm and a low temperature cross-sensitivity of ∼960 Pa/°C are achieved when a silica diaphragm of ∼500 nm in thickness is used. Moreover, the all-silica spherical structure enhanced the mechanical strength of the micro-cavity sensor, making it suitable for high sensitivity pressure sensing in harsh environments. PMID:24978213
The Effects of Phrenic Nerve Degeneration by Axotomy and Crush on the Electrical Activities of Diaphragm Muscles of Rats.
Alkiş, Mehmet Eşref; Kavak, Servet; Sayır, Fuat; Him, Aydin
The aim of this study was to investigate the effect of axotomy and crush-related degeneration on the electrical activities of diaphragm muscle strips of experimental rats. In the present study, twenty-one male Wistar-albino rats were used and divided into three groups. The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. Resting membrane potential (RMP) was decreased significantly in both crush and axotomy of diaphragm muscle strips of experimental rats (p < 0.05). Depolarization time (T DEP) and half-repolarization (1/2 RT) time were significantly prolonged in crush and axotomy rats (p < 0.05). Crushing or axotomizing the phrenic nerves may produce electrical activities in the diaphragm muscle of the rat by depolarization time and half-repolarization time prolonged in crush and axotomy rats. PMID:26972299
Structural Stress Analysis on the Rubber Diaphragm of Air-Operated Valve
NASA Astrophysics Data System (ADS)
Lee, Young-Shin; Cho, Taik-Dong; Ko, Sung-Ho; Lee, Hyun-Seung; Shin, Sung-Ky
Air-operated valves are used extensively in the power-generation industry for process control and system isolation functions. A study on the prevention of damage of an air operated valve is very important. Specially, diaphragm in an actuator of an air-operated valve has the highest damage rate. In this study, the stress of diaphragm with thickness change is analyzed. For this analysis, four experiments were conducted to obtain material properties of rubber. A stress analysis is carried out by commercial FEM code, ANSYS 8.0. It is compared with tension test to verify finite element analysis. From the result of analysis, the maximum stress happened at flange edge part, and the maximum displacement happened between flange edge and spring support. This study also finds out effect of the thickness about variable thickness. Even if a section area is same, the maximum stress is varied with the thickness of edge side.
Variation compensation and analysis on diaphragm curvature analysis for emphysema quantification on whole lung CT scans
NASA Astrophysics Data System (ADS)
Keller, Brad M.; Reeves, Anthony P.; Barr, R. Graham; Yankelevitz, David F.; Henschke, Claudia I.
CT scans allow for the quantitative evaluation of the anatomical bases of emphysema. Recently, a non-density based geometric measurement of lung diagphragm curvature has been proposed as a method for the quantification of emphysema from CT. This work analyzes variability of diaphragm curvature and evaluates the effectiveness of a compensation methodology for the reduction of this variability as compared to emphysema index. Using a dataset of 43 scan-pairs with less than a 100 day time-interval between scans, we find that the diaphragm curvature had a trend towards lower overall variability over emphysema index (95% CI:-9.7 to + 14.7 vs. -15.8 to +12.0), and that the variation of both measures was reduced after compensation. We conclude that the variation of the new measure can be considered comparable to the established measure and the compensation can reduce the apparent variation of quantitative measures successfully.
Training-induced alterations in young and senescent rat diaphragm muscle
NASA Technical Reports Server (NTRS)
Gosselin, Luc E.; Betlach, Michael; Vailas, Arthur C.; Thomas, D. P.
The effect of progressive treadmill exercise on oxidative capacity in three specific diaphragm muscle fiber types and on the capillary density of known fiber types was investigated in young (5 month) and senescent (23 months or older) rats. All animals were trained for 1 hr/day, 5 days weekly, for 10 weeks. Measurements of succinate dehydrogenase activity showed significant increases in all three fiber types in both the young and the senescent trained animals, compared with their sedentary controls. Fiber size and capillary density were not affected by exercise or age. The results demonstrate that the senescent costal diaphragm maintains its ability to adapt to an increased metabolic demand brought about by locomotor exercises.
Slosh testing of a spherical mercury propellant tank with positive-expulsion diaphragm
NASA Technical Reports Server (NTRS)
Ross, R. G., Jr.; Womack, J. R.
A preliminary investigation was conducted to evaluate the lateral slosh characteristics of a 23-cm diameter mercury propellant tank with a positive-expulsion diaphragm and 17.5% ullage. Data are presented for tank sinusoidal acceleration levels between 0.05 and 0.5 g at frequencies ranging from 5 to 50 Hz. Results indicate that slosh characteristics are highly nonlinear at acceleration levels approaching those in flight, and depend heavily on the shape and stiffness of the diaphragm. Nyquist plots of driving force over acceleration are shown to be a useful tool for determining natural frequency, damping, and modal mass characteristics. A computerized nonlinear least squares method for extracting the modal parameters from the Nyquist plots is described and results of applying the method are presented.
The effect of treatment on diaphragm contractility in obstructive sleep apnea syndrome.
El-Kabir, Desiree R; Polkey, Michael I; Lyall, Rebecca A; Williams, Adrian J; Moxham, John
In untreated obstructive sleep apnea syndrome (OSAS) inspiratory efforts are made against an occluded airway and diaphragm fatigue might therefore complicate OSAS. To test this hypothesis we measured twitch transdiaphragmatic pressure (Tw Pdi) in response to bilateral cervical magnetic stimulation of the phrenic nerve roots in nine patients with OSAS before and one month after successful therapy with nasal continuous positive airways pressure (nCPAP). The mean Tw Pdi before therapy was 23.2cm H2O and after therapy was 22.8cm H2O (P = 0.59); the mean change after initiation of nCPAP was 0.4cm H2O with 95% confidence intervals of -1.3cm H2O and +2.1 cm H2O. We conclude that low frequency diaphragm fatigue does not complicate untreated OSAS. PMID:14509556
Comparative study of characteristics of polysilicon pressure sensor with different diaphragm sizes and piezoresistor configurations
NASA Astrophysics Data System (ADS)
Kumar, S. Santosh; Ojha, Anuj K.; Kumar, Manish; Pant, B. D.
In this work, the fabrication and characterization of eight different polysilicon piezoresistive pressure sensors are reported. The sensors are fabricated simultaneously by putting the different designs on the same mask set and the sensitivity and non-linearity characteristics are plotted. The output responses of the different sensors are reported at three temperatures (-5, 25 and 55 °C). Out of the eight sensors with different diaphragm sizes and piezoresistor configurations, the sensor with diaphragm edge length of 1,280 µm and 2x1 configuration is found to have optimum characteristics, with good non-linearity and acceptable sensitivity. For this sensor, a sensitivity of 3.83-4.26 mV/Bar and non-linearity of <0.38 % are obtained in the pressure range of 0-30 Bar.
Anesthetic management of staged thoracoscopic repair of bilateral eventration of diaphragm in a neonate
Rao, Subramanian Hari; Natarajan, Saravanan; Pallavi, Vyapaka
Congenital eventration of the diaphragm is a rare disorder, the perioperative management of which is challenging. The introduction of thoracoscopic repair of these defects has considerably reduced the perioperative morbidity and mortality in these patients. In spite of the advantages of thoracoscopy which include smaller chest incisions, reduced postoperative pain, and more rapid postoperative recovery compared with thoracotomy, it is still inherent with complications unique to it. A clear understanding of the pathophysiologic changes, potential complications and institution of appropriate monitoring and good planning is essential for the safe conduct of thoracoscopic procedures in neonates. We describe the anesthetic management of staged thoracoscopic repair of bilateral congenital eventration of the diaphragm in a neonate. PMID:26957704
A modeling and vibration analysis of a piezoelectric micro-pump diaphragm
NASA Astrophysics Data System (ADS)
Kaviani, Samira; Bahrami, Mohsen; Esfahani, Amir Monemian; Parsi, Behzad
The vibration analysis of a micro-pump diaphragm is presented. A piezoelectric micro-pump is studied. For this purpose, a dynamic model of the micro-pump is derived. The micro-pump diaphragm is modeled as circular double membranes, a piezoelectric one as actuator and a silicon one for representing the membrane for pumping action. The damping effect of the fluid is introduced into the equations. Vibration analysis is established by explicitly solving the dynamic model. The natural frequencies and mode shapes are calculated. The orthogonality conditions of the system are discussed. To verify the results, the finite-element micro-pump model is developed in ANSYS software package. The results show that the two methods are well comparable.
Cystic Fibrosis below the Diaphragm: Abdominal Findings in Adult Patients.
Lavelle, Lisa P; McEvoy, Sinead H; Ni Mhurchu, Elaine; Gibney, Robert G; McMahon, Colm J; Heffernan, Eric J; Malone, Dermot E
Cystic fibrosis (CF) is the most common lethal autosomal recessive disease in the white population. Mutation of the CF transmembrane conductance regulator gene on chromosome 7 results in production of abnormally viscous mucus and secretions in the lungs of patients with CF. A similar pathologic process occurs in the gastrointestinal tract, pancreas, and hepatobiliary system. Inspissated mucus causes luminal obstruction and resultant clinical and radiologic complications associated with the disease process. Pancreatic involvement can result in exocrine and endocrine insufficiency, pancreatic atrophy, fatty replacement, or lipomatous pseudohypertrophy. Acute and chronic pancreatitis, pancreatic calcification, cysts, and cystosis also occur. Hepatic manifestations include hepatic steatosis, focal biliary and multilobular cirrhosis, and portal hypertension. Biliary complications include cholelithiasis, microgallbladder, and sclerosing cholangitis. The entire digestive tract can be involved. Distal ileal obstruction syndrome, intussusception, appendicitis, chronic constipation, colonic wall thickening, fibrosing colonopathy, pneumatosis intestinalis, gastroesophageal reflux, and peptic ulcer disease have been described. Renal manifestations include nephrolithiasis and secondary amyloidosis. The educational objectives of this review are to reveal the abdominal manifestations of CF to facilitate focused analysis of cross-sectional imaging in adult patients. Life expectancy in patients with CF continues to improve because of a combination of aggressive antibiotic treatment, improved emphasis on nutrition and physiotherapy, and development of promising new CF transmembrane conductance regulator modulators. As lung function and survival improve, extrapulmonary conditions, including hepatic and gastrointestinal malignancy, will be an increasing cause of morbidity and mortality. Awareness of the expected abdominal manifestations of CF may assist radiologists in identifying
Partial Support Ventilation and Mitochondrial-Targeted Antioxidants Protect against Ventilator-Induced Decreases in Diaphragm Muscle Protein Synthesis
Hudson, Matthew B.; Smuder, Ashley J.; Nelson, W. Bradley; Wiggs, Michael P.; Shimkus, Kevin L.; Fluckey, James D.; Szeto, Hazel H.; Powers, Scott K.
Mechanical ventilation (MV) is a life-saving intervention in patients in respiratory failure. Unfortunately, prolonged MV results in the rapid development of diaphragm atrophy and weakness. MV-induced diaphragmatic weakness is significant because inspiratory muscle dysfunction is a risk factor for problematic weaning from MV. Therefore, developing a clinical intervention to prevent MV-induced diaphragm atrophy is important. In this regard, MV-induced diaphragmatic atrophy occurs due to both increased proteolysis and decreased protein synthesis. While efforts to impede MV-induced increased proteolysis in the diaphragm are well-documented, only one study has investigated methods of preserving diaphragmatic protein synthesis during prolonged MV. Therefore, we evaluated the efficacy of two therapeutic interventions that, conceptually, have the potential to sustain protein synthesis in the rat diaphragm during prolonged MV. Specifically, these experiments were designed to: 1) determine if partial-support MV will protect against the decrease in diaphragmatic protein synthesis that occurs during prolonged full-support MV; and 2) establish if treatment with a mitochondrial-targeted antioxidant will maintain diaphragm protein synthesis during full-support MV. Compared to spontaneously breathing animals, full support MV resulted in a significant decline in diaphragmatic protein synthesis during 12 hours of MV. In contrast, diaphragm protein synthesis rates were maintained during partial support MV at levels comparable to spontaneous breathing animals. Further, treatment of animals with a mitochondrial-targeted antioxidant prevented oxidative stress during full support MV and maintained diaphragm protein synthesis at the level of spontaneous breathing animals. We conclude that treatment with mitochondrial-targeted antioxidants or the use of partial-support MV are potential strategies to preserve diaphragm protein synthesis during prolonged MV. PMID:26361212
Role of intrinsic aerobic capacity and ventilator-induced diaphragm dysfunction
Sollanek, Kurt J.; Smuder, Ashley J.; Wiggs, Michael P.; Morton, Aaron B.; Koch, Lauren G.; Britton, Steven L.
Prolonged mechanical ventilation (MV) leads to rapid diaphragmatic atrophy and contractile dysfunction, which is collectively termed "ventilator-induced diaphragm dysfunction" (VIDD). Interestingly, endurance exercise training prior to MV has been shown to protect against VIDD. Further, recent evidence reveals that sedentary animals selectively bred to possess a high aerobic capacity possess a similar skeletal muscle phenotype to muscles from endurance trained animals. Therefore, we tested the hypothesis that animals with a high intrinsic aerobic capacity would naturally be afforded protection against VIDD. To this end, animals were selectively bred over 33 generations to create two divergent strains, differing in aerobic capacity: high-capacity runners (HCR) and low-capacity runners (LCR). Both groups of animals were subjected to 12 h of MV and compared with nonventilated control animals within the same strains. As expected, contrasted to LCR animals, the diaphragm muscle from the HCR animals contained higher levels of oxidative enzymes (e.g., citrate synthase) and antioxidant enzymes (e.g., superoxide dismutase and catalase). Nonetheless, compared with nonventilated controls, prolonged MV resulted in significant diaphragmatic atrophy and impaired diaphragm contractile function in both the HCR and LCR animals, and the magnitude of VIDD did not differ between strains. In conclusion, these data demonstrate that possession of a high intrinsic aerobic capacity alone does not afford protection against VIDD. Importantly, these results suggest that endurance exercise training differentially alters the diaphragm phenotype to resist VIDD. Interestingly, levels of heat shock protein 72 did not differ between strains, thus potentially representing an important area of difference between animals with intrinsically high aerobic capacity and exercise-trained animals. PMID:25571991
Endurance training improves the resistance of rat diaphragm to exercise-induced oxidative stress.
Oh-ishi, S; Kizaki, T; Ookawara, T; Sakurai, T; Izawa, T; Nagata, N; Ohno, H
The current study was designed to test the hypothesis that endurance training improves the ability of the diaphragm muscle to resist exercise-induced oxidative stress. Twenty-eight male Wistar rats were assigned to either untrained or trained groups. Trained rats were treadmill-trained for 9 wk. Each group was subdivided into acutely exercised or nonexercised groups. Diaphragm muscle from each rat was analyzed to determine the levels of certain antioxidant enzymes: Mn-superoxide dismutase (Mn-SOD), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase, and catalase. In addition, interleukin-1 and myeloperoxidase levels were determined. Endurance training upregulated all of the antioxidant enzymes. Conversely, acute exercise increased glutathione peroxidase and catalase in untrained rats, while it had no overt effect on any antioxidant enzymes in trained rats. Both Mn-SOD and Cu,Zn-SOD contents and activities were increased with endurance training. However, the mRNA expressions of both forms of SOD did not show any significant change with endurance training. Acute exercise also increased the levels of interleukin-1 and myeloperoxidase in untrained rats but not in trained rats. Moreover, acute exercise significantly increased the ability of neutrophils to produce superoxide, especially in untrained rats. The results from this study demonstrate that endurance training can upregulate certain antioxidant enzyme activities in rat diaphragm muscle, indicating the potential for improvement of the resistance to intracellular reactive oxygen species. The results of this study also suggest that acute exercise may cause oxidative damage in rat diaphragm through the activation of the inflammatory pathway and that endurance training may minimize such an extracellular oxidative stress by acute exercise. PMID:9372679
Oxidative damage induced by cigarette smoke exposure in mice: impact on lung tissue and diaphragm muscle*,**
de Carlos, Samanta Portão; Dias, Alexandre Simões; Forgiarini, Luiz Alberto; Patricio, Patrícia Damiani; Graciano, Thaise; Nesi, Renata Tiscoski; Valença, Samuel; Chiappa, Adriana Meira Guntzel; Cipriano, Gerson; de Souza, Claudio Teodoro; Chiappa, Gaspar Rogério da Silva
OBJECTIVE: To evaluate oxidative damage (lipid oxidation, protein oxidation, thiobarbituric acid-reactive substances [TBARS], and carbonylation) and inflammation (expression of phosphorylated AMP-activated protein kinase and mammalian target of rapamycin [p-AMPK and p-mTOR, respectively]) in the lung parenchyma and diaphragm muscles of male C57BL-6 mice exposed to cigarette smoke (CS) for 7, 15, 30, 45, or 60 days. METHODS: Thirty-six male C57BL-6 mice were divided into six groups (n = 6/group): a control group; and five groups exposed to CS for 7, 15, 30, 45, and 60 days, respectively. RESULTS: Compared with control mice, CS-exposed mice presented lower body weights at 30 days. In CS-exposed mice (compared with control mice), the greatest differences (increases) in TBARS levels were observed on day 7 in diaphragm-muscle, compared with day 45 in lung tissue; the greatest differences (increases) in carbonyl levels were observed on day 7 in both tissue types; and sulfhydryl levels were lower, in both tissue types, at all time points. In lung tissue and diaphragm muscle, p-AMPK expression exhibited behavior similar to that of TBARS. Expression of p-mTOR was higher than the control value on days 7 and 15 in lung tissue, as it was on day 45 in diaphragm muscle. CONCLUSION: Our data demonstrate that CS exposure produces oxidative damage, not only in lung tissue but also (primarily) in muscle tissue, having an additional effect on respiratory muscle, as is frequently observed in smokers with COPD. PMID:25210964
Acoustic emission (AE) health monitoring of diaphragm type couplings using neural network analysis
NASA Astrophysics Data System (ADS)
Godinez-Azcuaga, Valery F.; Shu, Fong; Finlayson, Richard D.; O'Donnell, Bruce
This paper presents the latest results obtained from Acoustic Emission (AE) monitoring and detection of cracks and/or damage in diaphragm couplings, which are used in some aircraft and engine drive systems. Early detection of mechanical failure in aircraft drive train components is a key safety and economical issue with both military and civil sectors of aviation. One of these components is the diaphragm-type coupling, which has been evaluated as the ideal drive coupling for many application requirements such as high speed, high torque, and non-lubrication. Its flexible axial and angular displacement capabilities have made it indispensable for aircraft drive systems. However, diaphragm-type couplings may develop cracks during their operation. The ability to monitor, detect, identify, and isolate coupling cracks on an operational aircraft system is required in order to provide sufficient advance warning to preclude catastrophic failure. It is known that metallic structures generate characteristic Acoustic Emission (AE) during crack growth/propagation cycles. This phenomenon makes AE very attractive among various monitoring techniques for fault detection in diaphragm-type couplings. However, commercially available systems capable of automatic discrimination between signals from crack growth and normal mechanical noise are not readily available. Positive classification of signals requires experienced personnel and post-test data analysis, which tend to be a time-consuming, laborious, and expensive process. With further development of automated classifiers, AE can become a fully autonomous fault detection technique requiring no human intervention after implementation. AE has the potential to be fully integrated with automated query and response mechanisms for system/process monitoring and control.
Investigation of geometric design in piezoelectric microelectromechanical systems diaphragms for ultrasonic energy harvesting
NASA Astrophysics Data System (ADS)
Shi, Qiongfeng; Wang, Tao; Kobayashi, Takeshi; Lee, Chengkuo
Acoustic energy transfer (AET) has been widely used for contactless energy delivery to implantable devices. However, most of the energy harvesters (ultrasonic receivers) for AET are macro-scale transducers with large volume and limited operation bandwidth. Here, we propose and investigate two microelectromechanical systems diaphragm based piezoelectric ultrasonic energy harvesters (PUEHs) as an alternative for AET. The proposed PUEHs consist of micro-scale diaphragm array with different geometric parameter design. Diaphragms in PUEH-1 have large length to width ratio to achieve broadband property, while its energy harvesting performance is compromised. Diaphragms in PUEH-2 have smaller length to width ratio and thinner thickness to achieve both broadband property and good energy harvesting performance. Both PUEHs have miniaturized size and wide operation bandwidth that are ideally suitable to be integrated as power source for implantable biomedical devices. PUEH-1 has a merged -6 dB bandwidth of 74.5% with a central frequency of 350 kHz. PUEH-2 has two separate -6 dB bandwidth of 73.7%/30.8% with central frequencies of 285 kHz/650 kHz. They can adapt to various ultrasonic sources with different working frequency spectrum. Maximum output power is 34.3 nW and 84.3 nW for PUEH-1 and PUEH-2 at 1 mW/cm2 ultrasound intensity input, respectively. The associated power density is 0.734 μW/cm2 and 4.1 μW/cm2, respectively. Better energy harvesting performance is achieved for PUEH-2 because of the optimized length to width ratio and thickness design. Both PUEHs offer more alignment flexibility with more than 40% power when they are in the range of the ultrasound transmitter.
Implications for Cardiac Function Following Rescue of the Dystrophic Diaphragm in a Mouse Model of Duchenne Muscular Dystrophy.
Betts, Corinne A; Saleh, Amer F; Carr, Carolyn A; Muses, Sofia; Wells, Kim E; Hammond, Suzan M; Godfrey, Caroline; McClorey, Graham; Woffindale, Caroline; Clarke, Kieran; Wells, Dominic J; Gait, Michael J; Wood, Matthew J A
Duchenne muscular dystrophy (DMD) is caused by absence of the integral structural protein, dystrophin, which renders muscle fibres susceptible to injury and degeneration. This ultimately results in cardiorespiratory dysfunction, which is the predominant cause of death in DMD patients, and highlights the importance of therapeutic targeting of the cardiorespiratory system. While there is some evidence to suggest that restoring dystrophin in the diaphragm improves both respiratory and cardiac function, the role of the diaphragm is not well understood. Here using exon skipping oligonucleotides we predominantly restored dystrophin in the diaphragm and assessed cardiac function by MRI. This approach reduced diaphragmatic pathophysiology and markedly improved diaphragm function but did not improve cardiac function or pathophysiology, with or without exercise. Interestingly, exercise resulted in a reduction of dystrophin protein and exon skipping in the diaphragm. This suggests that treatment regimens may require modification in more active patients. In conclusion, whilst the diaphragm is an important respiratory muscle, it is likely that dystrophin needs to be restored in other tissues, including multiple accessory respiratory muscles, and of course the heart itself for appropriate therapeutic outcomes. This supports the requirement of a body-wide therapy to treat DMD. PMID:26113184
Modes of burning and axial structure of dc discharge with transverse diaphragm
NASA Astrophysics Data System (ADS)
Ogloblina, Polina; Lisovskiy, Valeriy; Yegorenkov, Vladimir
This paper reports the CVCs of the dc discharge with a diaphragm located between the electrodes. We determined the conditions when normal and abnormal modes of such a dc discharge can exist. The axial profiles of the plasma parameters (electron temperature, plasma potential and concentration) from the anode to the cathode sheath boundary were also registered with a single Langmuir probe. We demonstrated that at low nitrogen pressure of 0.1 Torr and the discharge current of 1 mA a double layer was formed near the diaphragm only in the cathode part of the tube whereas with the current of 10 mA the double layer expanded to the anode part too. At the nitrogen pressure of 0.5 Torr a positive column was observed in the anode part of the tube, and the double layers were formed on both sides of the diaphragm (in the anode as well as in the cathode parts of the tube). These layers accelerated electrons into the orifice. In all cases the maximum of the plasma concentration is located inside the orifice. and Scientific Center of Physical Technologies, Svobody Sq.6, Kharkov, 61022, Ukraine.
Interleukin-15 Administration Improves Diaphragm Muscle Pathology and Function in Dystrophic mdx Mice
Harcourt, Leah J.; Holmes, Anna Greer; Gregorevic, Paul; Schertzer, Jonathan D.; Stupka, Nicole; Plant, David R.; Lynch, Gordon S.
Interleukin (IL)-15, a cytokine expressed in skeletal muscle, has been shown to have muscle anabolic effects in vitro and to slow muscle wasting in rats with cancer cachexia. Whether IL-15 has therapeutic potential for diseases such as Duchenne muscular dystrophy (DMD) is unknown. We examined whether IL-15 administration could ameliorate the dystrophic pathology in the diaphragm muscle of the mdx mouse, an animal model for DMD. Four weeks of IL-15 treatment improved diaphragm strength, a highly significant finding because respiratory function is a mortality predictor in DMD. Enhanced diaphragm function was associated with increased muscle fiber cross-sectional area and decreased collagen infiltration. IL-15 administration was not associated with changes in T-cell populations or alterations in specific components of the ubiquitin proteasome pathway. To determine the effects of IL-15 on myofiber regeneration, muscles of IL-15-treated and untreated wild-type mice were injured myotoxically, and their functional recovery was assessed. IL-15 had a mild anabolic effect, increasing fiber cross-sectional area after 2 and 6 days but not after 10 days. Our findings demonstrate that IL-15 administration improves the pathophysiology of dystrophic muscle and highlight a possible therapeutic role for IL-15 in the treatment of neuromuscular disorders especially in which muscle wasting is indicated. PMID:15793293
Electro-active device using radial electric field piezo-diaphragm for sonic applications
NASA Technical Reports Server (NTRS)
Bryant, Robert G. (Inventor); Fox, Robert L. (Inventor)
An electro-active transducer for sonic applications includes a ferroelectric material sandwiched by first and second electrode patterns to form a piezo-diaphragm coupled to a mounting frame. When the device is used as a sonic actuator, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when voltage is applied to the electrode patterns. When the device is used as a sonic sensor, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when the ferroelectric material experiences deflection in a direction substantially perpendicular thereto. In each case, the electrode patterns are designed to cause the electric field to: i) originate at a region of the ferroelectric material between the first and second electrode patterns, and ii) extend radially outward from the region of the ferroelectric material (at which the electric field originates) and substantially parallel to the plane of the ferroelectric material. The mounting frame perimetrically surrounds the peizo-diaphragm and enables attachment of the piezo-diaphragm to a housing.
Inspiratory resistances facilitate the diaphragm response to transcranial stimulation in humans
Locher, Chrystèle; Raux, Mathieu; Fiamma, Marie-Noelle; Morélot-Panzini, Capucine; Zelter, Marc; Derenne, Jean-Philippe; Similowski, Thomas; Straus, Christian
Background Breathing in humans is dually controlled for metabolic (brainstem commands) and behavioral purposes (suprapontine commands) with reciprocal modulation through spinal integration. Whereas the ventilatory response to chemical stimuli arises from the brainstem, the compensation of mechanical loads in awake humans is thought to involve suprapontine mechanisms. The aim of this study was to test this hypothesis by examining the effects of inspiratory resistive loading on the response of the diaphragm to transcranial magnetic stimulation. Results Six healthy volunteers breathed room air without load (R0) and then against inspiratory resistances (5 and 20 cmH2O/L/s, R5 and R20). Ventilatory variables were recorded. Transcranial magnetic stimulation (TMS) was performed during early inspiration (I) or late expiration (E), giving rise to motor evoked potentials (MEPs) in the diaphragm (Di) and abductor pollicis brevis (APB). Breathing frequency significantly decreased during R20 without any other change. Resistive breathing had no effect on the amplitude of Di MEPs, but shortened their latency (R20: -0.903 ms, p = 0.03) when TMS was superimposed on inspiration. There was no change in APB MEPs. Conclusion Inspiratory resistive breathing facilitates the diaphragm response to TMS while it does not increase the automatic drive to breathe. We interpret these findings as a neurophysiological substratum of the suprapontine nature of inspiratory load compensation in awake humans. PMID:16875504
Contractile function is unaltered in diaphragm from mice lacking calcium release channel isoform 3
NASA Technical Reports Server (NTRS)
Clancy, J. S.; Takeshima, H.; Hamilton, S. L.; Reid, M. B.
Skeletal muscle expresses at least two isoforms of the calcium release channel in the sarcoplasmic reticulum (RyR1 and RyR3). Whereas the function of RyR1 is well defined, the physiological significance of RyR3 is unclear. Some authors have suggested that RyR3 participates in excitation-contraction coupling and that RyR3 may specifically confer resistance to fatigue. To test this hypothesis, we measured contractile function of diaphragm strips from adult RyR3-deficient mice (exon 2-targeted mutation) and their heterozygous and wild-type littermates. In unfatigued diaphragm, there were no differences in isometric contractile properties (twitch characteristics, force-frequency relationships, maximal force) among the three groups. Our fatigue protocol (30 Hz, 0.25 duty cycle, 37 degrees C) depressed force to 25% of the initial force; however, lack of RyR3 did not accelerate the decline in force production. The force-frequency relationship was shifted to higher frequencies and was depressed in fatigued diaphragm; lack of RyR3 did not exaggerate these changes. We therefore provide evidence that RyR3 deficiency does not alter contractile function of adult muscle before, during, or after fatigue.
Transplantation of glial progenitors that overexpress glutamate transporter GLT1 preserves diaphragm function following cervical SCI.
Li, Ke; Javed, Elham; Hala, Tamara J; Sannie, Daniel; Regan, Kathleen A; Maragakis, Nicholas J; Wright, Megan C; Poulsen, David J; Lepore, Angelo C
Approximately half of traumatic spinal cord injury (SCI) cases affect cervical regions, resulting in chronic respiratory compromise. The majority of these injuries affect midcervical levels, the location of phrenic motor neurons (PMNs) that innervate the diaphragm. A valuable opportunity exists following SCI for preventing PMN loss that occurs during secondary degeneration. One of the primary causes of secondary injury is excitotoxicity due to dysregulation of extracellular glutamate homeostasis. Astrocytes express glutamate transporter 1 (GLT1), which is responsible for the majority of CNS glutamate clearance. Given our observations of GLT1 dysfunction post-SCI, we evaluated intraspinal transplantation of Glial-Restricted Precursors (GRPs)--a class of lineage-restricted astrocyte progenitors--into ventral horn following cervical hemicontusion as a novel strategy for reconstituting GLT1 function, preventing excitotoxicity and protecting PMNs in the acutely injured spinal cord. We find that unmodified transplants express low levels of GLT1 in the injured spinal cord. To enhance their therapeutic properties, we engineered GRPs with AAV8 to overexpress GLT1 only in astrocytes using the GFA2 promoter, resulting in significantly increased GLT1 protein expression and functional glutamate uptake following astrocyte differentiation in vitro and after transplantation into C4 hemicontusion. Compared to medium-only control and unmodified GRPs, GLT1-overexpressing transplants reduced lesion size, diaphragm denervation and diaphragm dysfunction. Our findings demonstrate transplantation-based replacement of astrocyte GLT1 is a promising approach for SCI. PMID:25492561
Comparison of stethoscope bell and diaphragm, and of stethoscope tube length, for clinical blood pressure measurement
Griffiths, Clive; Murray, Alan; Zheng, Dingchang
Objective This study investigated the effect of stethoscope side and tube length on auscultatory blood pressure (BP) measurement. Methods Thirty-two healthy participants were studied. For each participant, four measurements with different combinations of stethoscope characteristics (bell or diaphragm side, standard or short tube length) were each recorded at two repeat sessions, and eight Korotkoff sound recordings were played twice on separate days to one experienced listener to determine the systolic and diastolic BPs (SBP and DBP). Analysis of variance was carried out to study the measurement repeatability between the two repeat sessions and between the two BP determinations on separate days, as well as the effects of stethoscope side and tube length. Results There was no significant paired difference between the repeat sessions and between the repeat determinations for both SBP and DBP (all P-values>0.10, except the repeat session for SBP using short tube and diaphragm). The key result was that there was a small but significantly higher DBP on using the bell in comparison with the diaphragm (0.66 mmHg, P=0.007), and a significantly higher SBP on using the short tube in comparison with the standard length (0.77 mmHg, P=0.008). Conclusion This study shows that stethoscope characteristics have only a small, although statistically significant, influence on clinical BP measurement. Although this helps understand the measurement technique and resolves questions in the published literature, the influence is not clinically significant. PMID:26741415
Isotonic contractile impairment due to genetic CLC-1 chloride channel deficiency in myotonic mouse diaphragm muscle.
van Lunteren, Erik; Pollarine, Jennifer; Moyer, Michelle
The hallmark of genetic CLC-1 chloride channel deficiency in myotonic humans, goats and mice is delayed muscle relaxation resulting from persistent electrical discharges. In addition to the ion channel defect, muscles from myotonic humans and mice also have major changes in fibre type and myosin isoform composition, but the extent to which this affects isometric contractions remains controversial. Many muscles, including the diaphragm, shorten considerably during normal activities, but shortening contractions have never been assessed in myotonic muscle. The present study tested the hypothesis that CLC-1 deficiency leads to an impairment of muscle isotonic contractile performance. This was tested in vitro on diaphragm muscle from SWR/J-Clcn1(adr-mto)/J myotonic mice. The CLC-1-deficient muscle demonstrated delayed relaxation, as expected. During the contractile phase, there were significant reductions in power and work across a number of stimulation frequencies and loads in CLC-1-deficient compared with normal muscle, the magnitude of which in many instances exceeded 50%. Reductions in shortening and velocity of shortening occurred, and were more pronounced when calculated as a function of absolute than relative load. However, the maximal unloaded shortening velocity calculated from Hill's equation was not altered significantly. The impaired isotonic contractile performance of CLC-1-deficient muscle persisted during fatigue-inducing stimulation. These data indicate that genetic CLC-1 chloride channel deficiency in mice not only produces myotonia but also substantially worsens the isotonic contractile performance of diaphragm muscle. PMID:17483199
Improving accuracy of markerless tracking of lung tumours in fluoroscopic video by incorporating diaphragm motion
NASA Astrophysics Data System (ADS)
Schwarz, M.; Teske, H.; Stoll, M.; Bendl, Rolf
Purpose: Conformal radiation of moving tumours is a challenging task in radiotherapy. Tumour motion induced by respiration can be visualized in fluoroscopic images recorded during patients breathing. Markerless methods making use of registration techniques can be used to estimate tumour motion. However, registration methods might fail when the tumour is hidden by ribs. Using motion of anatomical surrogates, like the diaphragm, is promising to model tumour motion. Methods: A sequence of 116 fluoroscopic images was analyzed and the tumour positions were manually defined by three experts. A block matching (BM) technique is used to calculate the displacement vector relatively to a selected reference image of the first breathing cycle. An enhanced method was developed: Positions, when the tumour is not located behind a rib, are taken as valid estimations of the tumour position. Furthermore, these valid estimations are used to establish a linear model of tumour position and diaphragm motion. For invalid estimations the calculated tumour positions are not taken into consideration, and instead the model is used to determine tumour motion. Results: Enhancing BM with a model of tumour motion from diaphragm motion improves the tracking accuracy when the tumour moves behind a rib. The error (mean ± SD) in longitudinal dimension was 2.0 ± 1.5mm using only BM and 1.0 ± 1.1mm when the enhanced approach was used. Conclusion: The enhanced tracking technique is capable to improve tracking accuracy compared to BM in the case that the tumour is occluded by ribs.
A self-priming, high performance, check valve diaphragm micropump made from SOI wafers
NASA Astrophysics Data System (ADS)
Kang, Jianke; Mantese, Joseph V.; Auner, Gregory W.
In this paper, we describe a self-priming high performance piezoelectrically actuated check valve diaphragm micropump. The micropump was fabricated from three wafers: two silicon-on-insulator (SOI) wafers and one silicon wafer. A process named 'SOI/SOI wafer bonding and etching back followed by a second wafer bonding' was developed in order to make the core components of this device which included an inlet check valve, an outlet check valve, a diaphragm and a chamber. The movable structures of this device, i.e. the check valves and the diaphragm, were fabricated from the device layers of the two bonded SOI wafers. Taking advantages of SOI wafer technology and etch-stop layers, the vertical parameters of the movable structures were precisely controlled in fabrication. The micropump was self-priming without any pre-filling process. The pumping rate of the micropump was linearly adjustable from 0 to 650l µm min-1 by adjusting frequency. The maximum pumping rate was 860 µl min-1 and the maximum pumping pressure was approximately 10.5 psi. The power consumption of the device was less than 1.2 mW.
Acceptability and use of the diaphragm and Replens lubricant gel for HIV prevention in Southern Africa.
Montgomery, Elizabeth T; Cheng, Helen; van der Straten, Ariane; Chidanyika, Agnes C; Lince, Naomi; Blanchard, Kelly; Ramjee, Gita; Nkala, Busisiwe; Padian, Nancy S
The acceptability and use of the diaphragm and lubricant gel were assessed as part of a large randomized controlled trial to determine the effectiveness of the methods in women's HIV acquisition. 2,452 intervention-arm women were enrolled at five Southern African clinics and followed quarterly for 12-24 months. Acceptability and use data were collected by face-to-face interviews at Month 3 and Exit. Participants were "very comfortable" with the physical mechanics of diaphragm use throughout the trial, and approval of the gel consistency, quantity and the applicator was high. At Exit, consistent disclosure of use (AOR 1.97, 95% CI: 1.10-3.55); an overall high diaphragm rating (AOR 1.84, 95% CI: 1.45-2.34) and perception of partner approval (AOR 1.75, 95% CI: 1.35-2.26) were the most significant acceptability factors independently associated with consistent use. Despite being female-initiated, disclosure of use to male partners and his perceived approval of the products were factors significantly associated with their consistent use. PMID:19757018
Elongation of the active anterior wall of the uro-genital pelvic diaphragm, a late unusual complication of paraplegia.
Jurascheck, F; Dollfus, P; Jacob-Chia, D
The situation of the usual bladder, prostate, membranous urethra channel, can vary, according to the morphology of the perineum which can be overstretched. A case of a young man with a T10 complete upper motor neurone lesion is presented. The normal anterior angulation at the prostate and membranous urethra junction was reduced anteriorly and pushed backwards, thus causing an added indirect factor of dysuria. The mechanism is discussed in comparison with other such late, but often overlooked consequences of alterations of the pelvic floor during micturition. PMID:7422341
Subcellular adaptation of the human diaphragm in chronic obstructive pulmonary disease.
Orozco-Levi, M; Gea, J; Lloreta, J L; Félez, M; Minguella, J; Serrano, S; Broquetas, J M
Pulmonary hyperinflation impairs the function of the diaphragm in patients with chronic obstructive pulmonary disease (COPD). However, it has been recently demonstrated that the muscle can counterbalance this deleterious effect, remodelling its structure (i.e. changing the proportion of different types of fibres). The aim of this study was to investigate whether the functional impairment present in COPD patients can be associated with structural subcellular changes of the diaphragm. Twenty individuals (60+/-9 yrs, 11 COPD patients and 9 subjects with normal spirometry) undergoing thoracotomy were included. Nutritional status and respiratory function were evaluated prior to surgery. Then, small samples of the costal diaphragm were obtained and processed for electron microscopy analysis. COPD patients showed a mean forced expiratory volume in one second (FEV1) of 60+/-9% predicted, a higher concentration of mitochondria (n(mit)) in their diaphragm than controls (0.62+/-0.16 versus 0.46+/-0.16 mitochondrial transections (mt) x microm(-2), p<0.05). On the other hand, subjects with air trapping (residual volume (RV)/total lung capacity (TLC) >37%) disclosed not only a higher n(mit) (0.63+/-0.17 versus 0.43+/-0.07 mt x microm(-2), p<0.05) but shorter sarcomeres (L(sar)) than subjects without this functional abnormality (2.08+/-0.16 to 2.27+/-0.15 microm, p<0.05). Glycogen stores were similar in COPD and controls. The severity of airways obstruction (i.e. FEV1) was associated with n(mit) (r=-0.555, p=0.01), while the amount of air trapping (i.e. RV/TLC) was found to correlate with both n(mit) (r=0.631, p=0.005) and L(sar) (r=-0.526, p<0.05). Finally, maximal inspiratory pressure (PI,max) inversely correlated with n(mit) (r=-0.547, p=0.01). In conclusion, impairment in lung function occurring in patients with chronic obstructive pulmonary disease is associated with subcellular changes in their diaphragm, namely a shortening in the length of sarcomeres and an increase in
Automatic assessment of average diaphragm motion trajectory from 4DCT images through machine learning
Li, Guang; Wei, Jie; Huang, Hailiang; Gaebler, Carl Philipp; Yuan, Amy; Deasy, Joseph O
To automatically estimate average diaphragm motion trajectory (ADMT) based on four-dimensional computed tomography (4DCT), facilitating clinical assessment of respiratory motion and motion variation and retrospective motion study. We have developed an effective motion extraction approach and a machine-learning-based algorithm to estimate the ADMT. Eleven patients with 22 sets of 4DCT images (4DCT1 at simulation and 4DCT2 at treatment) were studied. After automatically segmenting the lungs, the differential volume-per-slice (dVPS) curves of the left and right lungs were calculated as a function of slice number for each phase with respective to the full-exhalation. After 5-slice moving average was performed, the discrete cosine transform (DCT) was applied to analyze the dVPS curves in frequency domain. The dimensionality of the spectrum data was reduced by using several lowest frequency coefficients (fv) to account for most of the spectrum energy (Σfv2). Multiple linear regression (MLR) method was then applied to determine the weights of these frequencies by fitting the ground truth—the measured ADMT, which are represented by three pivot points of the diaphragm on each side. The 'leave-one-out' cross validation method was employed to analyze the statistical performance of the prediction results in three image sets: 4DCT1, 4DCT2, and 4DCT1 + 4DCT2. Seven lowest frequencies in DCT domain were found to be sufficient to approximate the patient dVPS curves (R = 91%−96% in MLR fitting). The mean error in the predicted ADMT using leave-one-out method was 0.3 ± 1.9 mm for the left-side diaphragm and 0.0 ± 1.4 mm for the right-side diaphragm. The prediction error is lower in 4DCT2 than 4DCT1, and is the lowest in 4DCT1 and 4DCT2 combined. This frequency-analysis-based machine learning technique was employed to predict the ADMT automatically with an acceptable error (0.2 ± 1.6 mm). This volumetric approach is not affected by the presence of the lung tumors
Effects of genetic obesity on rat upper airway muscle and diaphragm contractile properties.
van Lunteren, E
The contractile properties of pharyngeal respiratory muscle are altered in sleep apnoea and in conditions associated with sleep apnoea, such as ageing. We hypothesized that the contractile properties of the pharyngeal musculature are also altered by obesity, another factor associated with sleep apnoea. Studies compared a pharyngeal muscle, the sternohyoid, with the diaphragm. These were chosen as representative muscles whose contraction has opposing effects on upper airway patency. Both muscles were removed from nine lean and nine obese male Zucker rats (a genetic model of obesity), and isometric contractile properties were studied in vitro at 37 degrees C. For the sternohyoid muscle, in obese compared to lean animals there were no significant differences in isometric contraction time (15.2 +/- 0.3 vs 14.2 +/- 0.6 ms, respectively), half-relaxation time (13.6 +/- 0.5 vs 12.6 +/- 0.9 ms, respectively), twitch-to-tetanic tension ratio (0.22 +/- 0.02 vs 0.24 +/- 0.02, respectively), force-frequency relationship, fatigue resistance (2 min fatigue index 0.20 +/- 0.03 vs 0.18 +/- 0.02, respectively), or maximal degree of force potentiation during repetitive stimulation (52 +/- 11 vs 74 +/- 20% increase, respectively). For the diaphragm, the only significant effect of obesity was a lowering of the twitch-to-tetanic tension ratio (0.25 +/- 0.01 vs 0.29 +/- 0.02, respectively). In obese, as in lean animals, the sternohyoid had faster isometric twitch kinetics, a larger degree of force potentiation, and lower resistance to fatigue, than the diaphragm. In lean, but not obese, animals the sternohyoid twitch-to-tetanic tension ratio was lower than and the force frequency relationship was located to the right of that of the diaphragm. In this study, genetic obesity in rats was not associated with any significant alterations in the contractile properties of the pharyngeal muscle, and only small changes in the relationship between the contractile properties of the sternohyoid and
Effect of thyroid hormone on in vivo contractility of the canine diaphragm.
Miyashita, A; Suzuki, S; Suzuki, M; Numata, H; Suzuki, J; Akahori, T; Okubo, T
This study was designed to examine the effects of long-term (4 wk) administration of thyroid hormone on the in vivo contractility of the canine diaphragm. We implanted a pair of piezoelectric crystals chronically in the left crural and costal parts of the diaphragm by a midline laparotomy. Contractility was assessed by changes in the shortening of muscle fibers after twitch stimulation of both the crural and the costal parts of the diaphragm and in the transdiaphragmatic pressure (Pdi) after tetanic stimulation (10 to 100 Hz). As a reference, we also studied the response of the quadriceps femoris. Pretreatment measurements were taken 2 wk after surgery. Then, dogs assigned to the hyperthyroid group were given thyroid powder, 0.6 g/kg/day, orally for 4 wk. The control group was fed a diet without thyroid powder for 4 wk. Serum free-T4 level (RIA) in the hyperthyroid group (n = 9) increased from 0.68 +/- 0.07 to 5.72 +/- 0.95 ng/dl (mean +/- SE) (p less than 0.01). Pdi decreased 30 to 40% at all frequencies (p less than 0.05) except 10 Hz. Twitch shortening of the crural and costal parts, compared with pretreatment state, decreased significantly by 47.7 +/- 13.1 and 48.1 +/- 15.0%, respectively (p less than 0.05). The maximal rate of relaxation became significantly faster, by 63.5% (p less than 0.05), in the crural part, whereas that of the costal part tended to become faster but not to a significant extent. In the quadriceps femoris, although twitch force showed no change, both the maximal rate of contraction and maximal rate of relaxation became faster, and tetanic force decreased. Histologic examination of hyperthyroid dogs showed vacuolization and loss of fiber area of the diaphragm. These observations suggest that thyroid hormone impairs contractility of both the crural and costal parts of the diaphragm similarly, and that the decrease in contractility may be due to a loss of muscle mass and summation impairment of twitch contraction, which differs from that in
Developmental regulation of molecular signalling in fetal and neonatal diaphragm protein metabolism.
Song, Yong; Pillow, J Jane
Structural and functional immaturity of the preterm diaphragm predisposes the preterm baby to respiratory muscle weakness and consequent impaired efficiency of spontaneous respiration, potentially necessitating mechanical respiratory support. The ontogeny of several proteolytic genes (calpain, caspase-3, MAFbx and MuRF-1) changes dynamically with gestational and early postnatal development. We aimed to define the molecular signal cascades and triggers responsible for the dynamic changes in the proteolytic pathways during in utero and early postnatal development. Costal diaphragm was obtained immediately following euthanasia of fetal and newborn lambs from 75 to 200 days postconceptional age (term = 150 days). Gene expression of insulin-like growth factor 1 (IGF-1), tumour necrosis factor α (TNF-α) and myostatin decreased steadily in utero from 75 to 145 days (P < 0.05) and the transcripts increased again after birth except of myostatin. Rapid activation of the fork-head transcriptional factors of the O class (FOXO1) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways was observed at 24 h of postnatal age. Diaphragm reactive oxygen species (ROS) production increased over 29-fold at 24 h postnatal age, compared with the 145 days fetus (P < 0.01). Local (diaphragmatic) ROS accumulation occurred earlier and was more predominant than systemic (plasma) ROS. There were positive correlations between signalling transduction molecules (FOXO1 and NF-κB) and antioxidant gene expression (superoxide dismutase and glutathione peroxidase 1). We conclude that anabolic (IGF-1) and catabolic (TNF-α and myostatin) factors have a similar developmental pattern with a decreasing trend toward full term. This may reflect in utero integration of cellular events into low protein metabolism as the diaphragm matures in late gestation. On initiation of spontaneous breathing, ROS accumulated and potentially activated cascade of FOXO and NF
Nosenko, V.I.
Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.
In patients with a tumour invading the phrenic nerve does prophylactic diaphragm plication improve postoperative lung function?
Beattie, Gwyn W; Dunn, William G; Asif, Mohammed
A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In patients with tumours involving the phrenic nerve, does prophylactic diaphragm plication improve lung function following tumour resection?' Using the reported search, 258 papers were found of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Three case reports and one case series represent 37 patients in the literature along with two relevant animal studies. Patients treated with prophylactic plication at the time of injury or sacrifice of the phrenic nerve had reduced radiological evidence of diaphragm paralysis, lower reported shortness of breath and reduced requirement for ventilatory support. In patients with prophylactic diaphragm plication and a concurrent pulmonary resection, the predicted postoperative lung function correlated closely with the postoperative measured FEV1, FVC and gas transfer. The postoperative measured FEV1 was reported as 86-98%, the FVC 82-89% and gas transfer 97% of the predicted values. Two animal models investigate the mechanics of respiration, spirometry and gas exchange following diaphragmatic plication. A randomized control study in four dogs measured a 50% reduction in tidal volume and respiratory rate, a 40% decrease in arterial PO2 and a 43% increase in arterial CO2 when the phrenic nerve was crushed in animals with a pneumonectomy but without prophylactic diaphragm plication. A further randomized control animal study with 28 dogs found that plicating the diaphragm after unilateral phrenic nerve transection resulted in a significant increase in tidal volume and lung compliance and a significant decrease in respiratory frequency and the work of breathing. Prophylactic diaphragm plication may preserve lung function, reduce the risk of
The effect of progressive high-intensity inspiratory muscle training and fixed high-intensity inspiratory muscle training on the asymmetry of diaphragm thickness in stroke patients
Jung, Ju-hyeon; Kim, Nan-soo
[Purpose] This study investigated the effects of progressive load and fixed load high-intensity inspiratory muscle training on the asymmetry of diaphragm thickness in stroke patients. [Subjects] Twenty-one stroke patients were assigned to one of three groups: progressive load high-intensity inspiratory muscle training (n = 8), fixed load high-intensity inspiratory muscle training (n = 6), and controls (n = 7). [Methods] The progressive load and fixed load high-intensity inspiratory muscle training participants undertook an exercise program for 20 minutes, three times weekly, for 6 weeks. After each session, diaphragm thickness was measured using ultrasonography. The diaphragm asymmetry ratio and diaphragm thickening ratio were standardized using a formula. [Results] After intervention, the diaphragm asymmetry ratio significantly differed among the three groups, and the diaphragm asymmetry ratio significantly increased in the control group. A significant increase was identified in the diaphragm thickening ratio within the progressive load and fixed load high-intensity inspiratory muscle training groups. [Conclusion] Progressive load and fixed load high-intensity inspiratory muscle training decreased the asymmetry of diaphragm thickness in stroke patients; this effect, in turn, increased the diaphragm thickening ratio in stroke patients. The two interventions examined here should be selectively applied to individuals in the clinical field. PMID:26644689
Contribution of diaphragmatic power output to exercise-induced diaphragm fatigue.
Babcock, M A; Pegelow, D F; McClaran, S R; Suman, O E; Dempsey, J A
In nine normal humans we compared the effects on diaphragm fatigue of whole body exercise to exhaustion (86-93% of maximal O2 uptake for 13.2 +/- 2.0 min) to voluntary increases in the tidal integral of transdiaphragmatic pressure (integral of Pdi) while at rest at the same magnitude and frequency and for the same duration as those during exercise. After the endurance exercise, we found a consistent and significant fall (-26 +/- 2.9%, range -19.2 to -41.0%) in the Pdi response to supramaximal bilateral phrenic nerve stimulation at all stimulation frequencies (1, 10, and 20 Hz). Integral of Pdi.fB (where fB is breathing frequency) achieved during exercise averaged 509 +/- 81.0 cmH2O/min (range 304.0-957.0 cmH2O/min). At rest, voluntary production of integral of Pdi.fB, which was < 550-600 cmH2O/min (approximately 4 times the resting eupenic integral of Pdi.fB or 60-70% of Pdi capacity), did not result in significant diaphragmatic fatigue, whereas sustained voluntary production of integral of Pdi.fB in excess of these threshold values usually did result in significant fatigue. Thus, with few exceptions (5 of 23 tests) the ventilatory requirements of whole body endurance exercise demanded a level of integral of Pdi.fB that, by itself, was not fatiguing. The rested first dorsal interosseous muscle showed no fatigue in response to supramaximal ulnar nerve stimulation after whole body exercise. We postulate that the effects of locomotor muscle activity, such as competition for blood flow distribution and/or extracellular fluid acidosis, in conjunction with a contracting diaphragm account for most of the exercise-induced diaphragm fatigue. PMID:7649904
Improvement in Neural Respiratory Drive Estimation From Diaphragm Electromyographic Signals Using Fixed Sample Entropy.
Estrada, Luis; Torres, Abel; Sarlabous, Leonardo; Jane, Raimon
Diaphragm electromyography is a valuable technique for the recording of electrical activity of the diaphragm. The analysis of diaphragm electromyographic (EMGdi) signal amplitude is an alternative approach for the quantification of the neural respiratory drive (NRD). The EMGdi signal is, however, corrupted by electrocardiographic (ECG) activity, and this presence of cardiac activity can make the EMGdi interpretation more difficult. Traditionally, the EMGdi amplitude has been estimated using the average rectified value (ARV) and the root mean square (RMS). In this study, surface EMGdi signals were analyzed using the fixed sample entropy (fSampEn) algorithm, and compared to the traditional ARV and RMS methods. The fSampEn is calculated using a tolerance value fixed and independent of the standard deviation of the analysis window. Thus, this method quantifies the amplitude of the complex components of stochastic signals (such as EMGdi), and being less affected by changes in amplitude due to less complex components (such as ECG). The proposed method was tested in synthetic and recorded EMGdi signals. fSampEn was less sensitive to the effect of cardiac activity on EMGdi signals with different levels of NRD than ARV and RMS amplitude parameters. The mean and standard deviation of the Pearson's correlation values between inspiratory mouth pressure (an indirect measure of the respiratory muscle activity) and fSampEn, ARV, and RMS parameters, estimated in the recorded EMGdi signal at tidal volume (without inspiratory load), were 0.38±0.12, 0.27±0.11 , and 0.11±0.13, respectively. Whereas at 33 cmH2O (maximum inspiratory load) were 0.83±0.02, 0.76±0.07, and 0.61±0.19 , respectively. Our findings suggest that the proposed method may improve the evaluation of NRD. PMID:25667362
Modeling and Parameter Estimation of Spacecraft Fuel Slosh with Diaphragms Using Pendulum Analogs
NASA Technical Reports Server (NTRS)
Chatman, Yadira; Gangadharan, Sathya; Schlee, Keith; Ristow, James; Suderman, James; Walker, Charles; Hubert, Carl
Prediction and control of liquid slosh in moving containers is an important consideration in the design of spacecraft and launch vehicle control systems. Even with modern computing systems, CFD type simulations are not fast enough to allow for large scale Monte Carlo analyses of spacecraft and launch vehicle dynamic behavior with slosh included. It is still desirable to use some type of simplified mechanical analog for the slosh to shorten computation time. Analytic determination of the slosh analog parameters has met with mixed success and is made even more difficult by the introduction of propellant management devices such as elastomeric diaphragms. By subjecting full-sized fuel tanks with actual flight fuel loads to motion similar to that experienced in flight and measuring the forces experienced by the tanks, these parameters can be determined experimentally. Currently, the identification of the model parameters is a laborious trial-and-error process in which the hand-derived equations of motion for the mechanical analog are evaluated and their results compared with the experimental results. This paper will describe efforts by the university component of a team comprised of NASA's Launch Services Program, Embry Riddle Aeronautical University, Southwest Research Institute and Hubert Astronautics to improve the accuracy and efficiency of modeling techniques used to predict these types of motions. Of particular interest is the effect of diaphragms and bladders on the slosh dynamics and how best to model these devices. The previous research was an effort to automate the process of slosh model parameter identification using a MATLAB/SimMechanics-based computer simulation. These results are the first step in applying the same computer estimation to a full-size tank and vehicle propulsion system. The introduction of diaphragms to this experimental set-up will aid in a better and more complete prediction of fuel slosh characteristics and behavior. Automating the
Mechanical forces contribute to neonatal lung growth: the influence of altered diaphragm function in piglets.
Price, M R; Galantowicz, M E; Stolar, C J
Neonatal lung growth is controlled in part by mechanical forces. Altered mechanical forces precipitated by phrenectomy or prosthetic replacement of the diaphragm result in altered thoracic volume relationships, which, in turn, change lung distending pressures and or thoracic volume. These effects might contribute to regional lung growth. We postulated a relationship between altered thoracic mechanical forces and changes in lung growth and asked if altered diaphragm function influenced regional lung growth. Piglets (28d, 7-8kg), were assigned to left transthoracic phrenectomy (P), prosthetic diaphragm replacement (PDR), or sham (S), (n = 6). After a mean 10 days, piglets were studied with tracheostomy and regional pleural pressure transducers. Integrated lung volumes (LV) were recorded with intrapleural pressure (Pip). Dynamic compliance (Cdyn) was calculated (dV/dP). After sacrifice continuous pressure volume (P/V) curves were generated. Lungs were then cut into 4 quadrants based on relationship to R/L bronchus and processed for DNA content and total protein indexes. Analysis of data were made within and between groups. Body weight and gain were similar in all. LV, Pip, Cdyn, and P/V were not significantly different in PDR and P compared with S. Pip differences between thoracic regions within each group were significant for PDR and showed LU less than RU, LL less than RL (P less than 0.05). RU and RL Pip in the PDR group were the same as S. Pip in the P group were decreased in the RU, LU, and LL but only the LL approached significance. Whole lung wet weights were decreased (P less than .05) in P compared to PDR and S.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1501014
Localization of Serotoninergic Neurons that Participate in Regulating Diaphragm Activity in the Cat
Rice, Cory D.; Lois, James H.; Kerman, Ilan A.; Yates, Bill J.
Although a considerable body of literature indicates that serotoninergic neurons affect diaphragm activity both through direct inputs to phrenic motoneurons and multisynaptic connections involving the brainstem respiratory groups, the locations of the serotoninergic neurons that modulate breathing have not been well defined. The present study identified these neurons in cats by combining the transneuronal retrograde transport of rabies virus from the diaphragm with the immunohistochemical detection of the N-terminal region of tryptophan hydroxylase-2 (TPH2), the brain-specific isoform of the enzyme responsible for the initial and rate-limiting step in serotonin synthesis. TPH2-immunopositive neurons were present in the midline raphe nuclei, formed a column in the ventrolateral medulla near the lateral reticular nucleus, and were spread across the dorsal portion of the pons just below the fourth ventricle. In most animals, only a small fraction of neurons (typically < 20%) labeled for TPH2 in each of the medullary raphe nuclei and the medullary ventrolateral column were infected with rabies virus. However, the percentage of medullary neurons dual-labeled for both rabies and TPH2 was much higher in animals with very advanced infections where virus had spread transneuronally through many synapses. Furthermore, in all cases, TPH2-immunopositive neurons that were infected by rabies virus were significantly less prevalent in the pons than the medulla. These findings suggest that although serotoninergic neurons with direct influences on diaphragm activity are widely scattered in the brainstem, the majority of these neurons are located in the medulla. Many nonserotoninergic neurons in the raphe nuclei were also infected with rabies virus, indicating that midline cells utilizing multiple neurotransmitters participate in the control of breathing. PMID:19433074
Influence of maturation on infant diaphragm function assessed by magnetic stimulation of phrenic nerves.
Dimitriou, Gabriel; Greenough, Anne; Moxham, John; Rafferty, Gerrard F
Infant diaphragm function may be adversely affected in a variety of disorders and conditions. Key to establishing an accurate diagnosis are appropriate control data. The aim of this study was to determine the effect of maturation on diaphragm function, using a nonvolitional test. Diaphragm function was assessed by measuring the transdiaphragmatic pressure (Pdi) generated by magnetic stimulation of the phrenic nerves. Ballon catheters were positioned in the lower third of the esophagus and stomach. Esophageal (Pes) and gastric (Pgas) pressure changes were measured using differential pressure transducers. The pressure signals were amplified and displayed in real time on a computer (running Labview trade mark software) and Pdi derived by online subtraction of Pes from Pgas. Twenty-nine infants (14 born preterm), at a median gestational age of 37 (range, 25-42) weeks, were studied at a median postconceptional age (PCA) of 39 (range, 32-44) weeks. At time of measurement, none had respiratory problems or were hyperinflated (functional residual capacity ranged from 23-35 mL/kg). The preterm infants had significantly lower transdiaphragmatic pressures responses following median left (4.0, range 2.5-6.8 cmH(2)O vs. 4.8, range 2.8-7.2 cmH(2)O) and median right phrenic nerve stimulation (3.6, range 2.6-4.8 cmH(2)O vs. 4.3, range 2.7-6.8 cmH(2)O) (P < 0.05) than term infants. Following left and right phrenic nerve stimulation, Pdi correlated significantly with gestational age (r = 0.4, P < 0.05, and r = 0.4, P < 0.05, respectively) and PCA (r = 0.37, P = 0.05, and r = 0.56, P < 0.01, respectively). We conclude that gestational age at birth and postconceptional age at time of measurements must be taken into account when interpreting the results of infant diaphragm function tests. PMID:12461734
Silk fibroin diaphragm-based fiber-tip Fabry-Perot pressure sensor.
Cheng, Linghao; Wang, Cengzhong; Huang, Yunyun; Liang, Hao; Guan, Bai-Ou
A miniature fiber-optic Fabry-Perot is built on the tip of a single mode fiber with a thin silk fibroin film as the diaphragm for pressure measurement. The silk fibroin film is regenerated from aqueous silk fibroin solution obtained by an environmentally benign fabrication process, which exhibits excellent optical and physicochemical properties, such as transparency in visible and near infrared region, membrane-forming ability, good adhesion, and high mechanical strength. The resulted Fabry-Perot pressure sensor is therefore highly biocompatible and shows good airtightness with a response of 12.3 nm/kPa in terms of cavity length change. PMID:27557238
[Nervous regulation of glycogen concentration and the lactate dehydrogenase isoenzyme spectrum in the diaphragm of rats].
Iakovlev, V F
Content of glycogen, activity of lactate dehydrogenase (LDH) and its isoenzyme spectrum were studied in two cases of partial diaphragm denervation as well as in electro-stimulation of separate phrenic nerve branches. Dissimilar postdenervational alterations were observed in the content of glycogen and in the isozyme spectrum of LDH, which depended on the type of partial denervation. Stimulation of individual branches of the phrenic nerve showed that they separately affected the synthesis and consumption of glycogen. The data obtained suggest the nervous regulation of glycogensynthetic processes in muscle tissue. PMID:7467206
Innervation of periesophageal region of cat's diaphragm - Implication for studies of control of vomiting
NASA Technical Reports Server (NTRS)
Tan, L. K.; Miller, A. D.
The extent of the region of the diaphragm around the esophagus that displays greatly reduced activity during the expulsive phase of vomiting was determined from electromyographic studies in cats to be about 0.75-1.0 cm from the esophagus. Horseradish peroxidase injected into this region retrogradely labeled motoneurons throughout most of the rostral-caudal extent of the phrenic nucleus, with the exception of caudal C6 and rostral C7. This widespread intermingling of motoneurons that innervate the region of reduced activity with other phrenic motoneurons creates a difficulty for needed follow-up studies of diaphragmatic control during vomiting.
Hepatocellular carcinoma with extension to the diaphragm, falciform ligament, rectus abdominis and paraumbilical vein
Kaur, R; Abdullah, BJJ; Rajasingam, V
Hepatocellular carcinoma is the most common primary tumour of the liver. The most common extrahepatic metastatic sites are the lung, lymph nodes, bones and adrenal glands. All forms of HCC demonstrate a tendency for vascular invasion, producing extensive intrahepatic metastases and, occasionally, portal vein or inferior vena cava extension with spread into the right atrium in extreme cases. Tumour spread of abdominal diseases via hepatic ligaments has also been previously reported. We report a rare case of hepatocellular carcinoma with extension into the falciform ligament, overlying rectus sheath and adjacent diaphragm with concomitant infiltration into the recanalised paraumbilical vein. PMID:21611019
A mathematical model of ionic transport in a porous diaphragm of a chrome-alum cell
NASA Astrophysics Data System (ADS)
Vidal, Roberto; Duby, Paul; West, Alan C.
A model of the homogeneous chemistry and transport processes within the separator of a chrome-alum electrowinning cell is introduced, discussed, and compared to experiment. The influences of diffusion, electromigration, and convection are included; it is found that convection was the dominant mode of transport for the experimental conditions. Simulation results explain experimental observations concerning an apparent disappearance of dichromate ions produced at the cell anode. The relation between potential drop across the diaphragm and the current and fluid flow is also illustrated. The model is used to recommend future experimental and theoretical work.
Prone decubitus: A solution to inferior wall attenuation in thallium-201 myocardial tomography
Esquerre, J.P.; Coca, F.J.; Martinez, S.J.; Guiraud, R.F.
We propose an efficient method to suppress inferior wall attenuation in /sup 201/TI 180 degrees myocardial tomography. We systematically performed redistribution studies in both supine and prone decubitus, assuming that the latter should result in shifting with respect to each other's cardiac structures and diaphragm as well as subphrenic organs possibly responsible for attenuation. The comparison of both studies in 25 normal subjects by visual interpretation and circumferential profiles analysis showed a complete suppression of significant attenuation in the inferior wall in prone studies. In addition and consequently, the standard deviation of activity in this area was markedly reduced and became close to its value in anterior and lateral walls. This simple technique now routinely performed in over 400 patients drastically improves specificity in the evaluation of inferior wall abnormalities by suppressing attenuation artifacts and, incidently, the effect of high individual variability in left phrenic and subphrenic anatomic configuration.
Exercise training causes differential changes in gene expression in diaphragm arteries and 2A arterioles of obese rats.
Laughlin, M Harold; Padilla, Jaume; Jenkins, Nathan T; Thorne, Pamela K; Martin, Jeffrey S; Rector, R Scott; Akter, Sadia; Davis, J Wade
We employed next-generation, transcriptome-wide RNA sequencing (RNA-Seq) technology to assess the effects of two different exercise training protocols on transcriptional profiles in diaphragm second-order arterioles (D2a) and in the diaphragm feed artery (DFA) from Otsuka Long Evans Tokushima Fatty (OLETF) rats. Arterioles were isolated from the diaphragm of OLETF rats that underwent an endurance exercise training program (EX; n = 13), interval sprint training program (SPRINT; n = 14), or remained sedentary (Sed; n = 12). Our hypothesis was that exercise training would have similar effects on gene expression in the diaphragm and soleus muscle arterioles because diaphragm blood flow increases during exercise to a similar extent as in soleus. Results reveal that several canonical pathways that were significantly altered by exercise in limb skeletal muscles were not among the pathways significantly changed in the diaphragm arterioles including actin cytoskeleton signaling, role of NFAT in regulation of immune response, protein kinase A signaling, and protein ubiquitination pathway. EX training altered the expression of a smaller number of genes than did SPRINT in the DFA but induced a larger number of genes with altered expression in the D2a than did SPRINT. In fact, FDR differential expression analysis (FDR, 10%) indicated that only two genes exhibited altered expression in D2a of SPRINT rats. Very few of the genes that exhibited altered expression in the DFA or D2a were also altered in limb muscle arterioles. Finally, results indicate that the 2a arterioles of soleus muscle (S2a) from endurance-trained animals and the DFA of SPRINT animals exhibited the largest number of genes with altered expression. PMID:26183478
Maternal Creatine Supplementation during Pregnancy Prevents Long-Term Changes in Diaphragm Muscle Structure and Function after Birth Asphyxia.
LaRosa, Domenic A; Ellery, Stacey J; Parkington, Helena C; Snow, Rod J; Walker, David W; Dickinson, Hayley
Using a model of birth asphyxia, we previously reported significant structural and functional deficits in the diaphragm muscle in spiny mice, deficits that are prevented by supplementing the maternal diet with 5% creatine from mid-pregnancy. The long-term effects of this exposure are unknown. Pregnant spiny mice were fed control or 5% creatine-supplemented diet for the second half of pregnancy, and fetuses were delivered by caesarean section with or without 7.5 min of in-utero asphyxia. Surviving pups were raised by a cross-foster dam until 33±2 days of age when they were euthanized to obtain the diaphragm muscle for ex-vivo study of twitch tension and muscle fatigue, and for structural and enzymatic analyses. Functional analysis of the diaphragm revealed no differences in single twitch contractile parameters between any groups. However, muscle fatigue, induced by stimulation of diaphragm strips with a train of pulses (330 ms train/sec, 40 Hz) for 300 sec, was significantly greater for asphyxia pups compared with controls (p<0.05), and this did not occur in diaphragms of creatine + asphyxia pups. Birth asphyxia resulted in a significant increase in the proportion of glycolytic, fast-twitch fibres and a reduction in oxidative capacity of Type I and IIb fibres in male offspring, as well as reduced cross-sectional area of all muscle fibre types (Type I, IIa, IIb/d) in both males and females at 33 days of age. None of these changes were observed in creatine + asphyxia animals. Thus, the changes in diaphragm fatigue and structure induced by birth asphyxia persist long-term but are prevented by maternal creatine supplementation. PMID:26930669
Maternal Creatine Supplementation during Pregnancy Prevents Long-Term Changes in Diaphragm Muscle Structure and Function after Birth Asphyxia
LaRosa, Domenic A.; Ellery, Stacey J.; Parkington, Helena C.; Snow, Rod J.
Using a model of birth asphyxia, we previously reported significant structural and functional deficits in the diaphragm muscle in spiny mice, deficits that are prevented by supplementing the maternal diet with 5% creatine from mid-pregnancy. The long-term effects of this exposure are unknown. Pregnant spiny mice were fed control or 5% creatine-supplemented diet for the second half of pregnancy, and fetuses were delivered by caesarean section with or without 7.5 min of in-utero asphyxia. Surviving pups were raised by a cross-foster dam until 33±2 days of age when they were euthanized to obtain the diaphragm muscle for ex-vivo study of twitch tension and muscle fatigue, and for structural and enzymatic analyses. Functional analysis of the diaphragm revealed no differences in single twitch contractile parameters between any groups. However, muscle fatigue, induced by stimulation of diaphragm strips with a train of pulses (330ms train/sec, 40Hz) for 300sec, was significantly greater for asphyxia pups compared with controls (p<0.05), and this did not occur in diaphragms of creatine + asphyxia pups. Birth asphyxia resulted in a significant increase in the proportion of glycolytic, fast-twitch fibres and a reduction in oxidative capacity of Type I and IIb fibres in male offspring, as well as reduced cross-sectional area of all muscle fibre types (Type I, IIa, IIb/d) in both males and females at 33 days of age. None of these changes were observed in creatine + asphyxia animals. Thus, the changes in diaphragm fatigue and structure induced by birth asphyxia persist long-term but are prevented by maternal creatine supplementation. PMID:26930669
Evaluation of COPD's diaphragm motion extracted from 4D-MRI
NASA Astrophysics Data System (ADS)
Swastika, Windra; Masuda, Yoshitada; Kawata, Naoko; Matsumoto, Koji; Suzuki, Toshio; Iesato, Ken; Tada, Yuji; Sugiura, Toshihiko; Tanabe, Nobuhiro; Tatsumi, Koichiro; Ohnishi, Takashi; Haneishi, Hideaki
We have developed a method called intersection profile method to construct a 4D-MRI (3D+time) from time-series of 2D-MRI. The basic idea is to find the best matching of the intersection profile from the time series of 2D-MRI in sagittal plane (navigator slice) and time series of 2D-MRI in coronal plane (data slice). In this study, we use 4D-MRI to semiautomatically extract the right diaphragm motion of 16 subjects (8 healthy subjects and 8 COPD patients). The diaphragm motion is then evaluated quantitatively by calculating the displacement of each subjects and normalized it. We also generate phase-length map to view and locate paradoxical motion of the COPD patients. The quantitative results of the normalized displacement shows that COPD patients tend to have smaller displacement compared to healthy subjects. The average normalized displacement of total 8 COPD patients is 9.4mm and the average of normalized displacement of 8 healthy volunteers is 15.3mm. The generated phase-length maps show that not all of the COPD patients have paradoxical motion, however if it has paradoxical motion, the phase-length map is able to locate where does it occur.
Piezoelectric circular diaphragm with mechanically induced pre-stress for energy harvesting
NASA Astrophysics Data System (ADS)
Palosaari, J.; Leinonen, M.; Juuti, J.; Hannu, J.; Jantunen, H.
This paper presents the results of a piezoelectric circular diaphragm harvester utilising a unique measurement setup with tailored input force (walk profile), adjustable mechanical pre-stress, and simultaneous measurement of the harvested energy output and input force pressure. The harvester, incorporating the pre-stressing mechanism, consisted of a 191 μm thick PZ-5A piezoelectric disc (Ø 34.5 mm) and a 100 μm thick steel plate (Ø 45.5 mm). Its performance was measured with pressure cycles at a frequency of 0.96 Hz. Harvested energy was measured as a function of the pre-stressing state, the applied force, and the pressure profile. The optimal bending pre-stress was found to improve the efficiency of harvesting by ˜141% compared to the case without pre-stress. The maximum obtained efficiency was 14.7%, and the maximum average power density of 6.06 mW cm-3 was measured for a unimorph diaphragm energy harvester. The results show that the pre-stressing technique is an effective method to improve the efficiency and generated power in this type of piezoelectric harvester, potentially enabling it to power different portable devices and sensors in future applications.
FE-Simulation of the Diaphragm Draping Process for NCF on a Macro-Scale Level
NASA Astrophysics Data System (ADS)
Leutz, Daniel; Kluepfel, Maximilian; Dumont, François; Hinterhoelzl, Roland; Drechsler, Klaus; Weimer, Christian
Preforming of dry Non-Crimp Fabric (NCF) enables a near-net-shape structure of CFRP-parts before resin injection. Besides the common punch forming or hood forming, the diaphragm draping process offers greater possibility for automatable forming of textile reinforcements for composites. But the highly extendable membrane used to drape the preform over the tool influences greatly the draping results and may even introduce specific defects. To investigate the process mechanics of the single diaphragm process a FE-based simulation has been performed. A macro-scale model was set up by using a biphase shell element to model the reinforcement material. As first application a single NCF ply draped over a mold for a generic helicopter frame structure has been studied. Experiments have been carried out in order to validate the simulation results and to investigate the capability of this approach to present different types of defects like e.g. wrinkling. Based on that work a detailed study has been done on drapeability of a specific tailored reinforcement (multiple plies of NCF locally stitched together) [6]. The stitching for instance could lead to a locking of the fabric mechanics, which in turn results in a limited formability and local defects in the stitching region.
Effect of spaceflight on oxidative and antioxidant enzyme activity in rat diaphragm and intercostal muscles
NASA Technical Reports Server (NTRS)
Lee, Mona D.; Tuttle, Ronald; Girten, Beverly
There are limited data regarding changes in oxidative and antioxidant enzymes induced by simulated or actual weightlessness, and any additional information would provide insight into potential mechanisms involving other changes observed in muscles from animals previously flown in space. Thus, the NASA Biospecimen Sharing Program was an opportunity to collect valuable information. Oxidative and antioxidant enzyme levels, as well as lipid peroxidation, were measured in respiratory muscles from rates flown on board Space Shuttle mission STS-54. The results indicated that there was an increasing trend in citrate synthase activity in the flight diaphragm when compared to ground based controls, and there were no significant changes observed in the intercostal muscles for any of the parameters. However, the lipid peroxidation was significantly (p less than 0.05) decreased in the flight diaphragm. These results indicate that 6 day exposure to microgravity may have a different effect on oxidative and antioxidant activity in rat respiratory muscles when compared to data from previous 14 day hindlimb suspension studies.
Design Considerations of a Slit Diaphragm Flexure Used in a Precision Mirror Gimbal
Cox, B. C., Kaufman, M. I.
Two precision mirror gimbals were designed using slit diaphragm flexures to provide two-axis precision mirror alignment in space-limited applications. Both gimbals are currently in use in diagnostics at the National Ignition Facility: one design in the Gamma Reaction History (GRH) diagnostic and the other in the Neutron Imaging System (NIS) diagnostic. The GRH gimbal has an adjustment sensitivity of 0.1 mrad about both axes and a total adjustment capability of ±6°; the NIS gimbal has an adjustment sensitivity of 0.8 μrad about both axes and a total adjustment range of ±3°. Both slit diaphragm flexures were electro-discharge machined out of high-strength titanium and utilize stainless steel stiffeners. The stiffener-flexure design results in adjustment axes with excellent orthogonality and centering with respect to the mirror in a single stage; a typical two-axis gimbal flexure requires two stages. Finite element analyses are presented for both flexure designs, and a design optimization of the GRH flexure is discussed.
Design considerations of a slit diaphragm flexure used in a precision mirror gimbal
NASA Astrophysics Data System (ADS)
Cox, Brian; Kaufman, Morris
Two precision mirror gimbals were designed using slit diaphragm flexures to provide two-axis precision mirror alignment in space-limited applications. Both gimbals are currently in use in diagnostics at the National Ignition Facility: one design in the Gamma Reaction History (GRH) diagnostic and the other in the Neutron Imaging System (NIS) diagnostic. The GRH gimbal has an adjustment sensitivity of 0.1 mrad about both axes and a total adjustment capability of +/-6° the NIS gimbal has an adjustment sensitivity of 0.8 μrad about both axes and a total adjustment range of +/-3°. Both slit diaphragm flexures were electro-discharge machined out of high-strength titanium and utilize stainless steel stiffeners. The stiffener-flexure design results in adjustment axes with excellent orthogonality and centering with respect to the mirror in a single stage; a typical two-axis gimbal flexure requires two stages. Finite element analyses are presented for both flexure designs, and a design optimization of the GRH flexure is discussed.
Laterally Driven Resonant Pressure Sensor with Etched Silicon Dual Diaphragms and Combined Beams.
Du, Xiaohui; Liu, Yifang; Li, Anlin; Zhou, Zhou; Sun, Daoheng; Wang, Lingyun
A novel structure of the resonant pressure sensor is presented in this paper, which tactfully employs intercoupling between dual pressure-sensing diaphragms and a laterally driven resonant strain gauge. After the resonant pressure sensor principle is introduced, the coupling mechanism of the diaphragms and resonator is analyzed and the frequency equation of the resonator based on the triangle geometry theory is developed for this new coupling structure. The finite element (FE) simulation results match the theoretical analysis over the full scale of the device. This pressure sensor was first fabricated by dry/wet etching and thermal silicon bonding, followed by vacuum-packaging using anodic bonding technology. The test maximum error of the fabricated sensor is 0.0310%F.S. (full scale) in the range of 30 to 190 kPa, its pressure sensitivity is negative and exceeding 8 Hz/kPa, and its Q-factor reaches 20,000 after wafer vacuum-packaging. A novel resonant pressure sensor with high accuracy is presented in this paper. PMID:26821031
Effects of theophylline on pharyngeal dilator and diaphragm muscle contractile properties.
van Lunteren, E; Vafaie, H; Miller, M J
Theophylline alleviates central and obstructive apneas of prematurity, and may improve adult obstructive sleep apnea. One mechanism of action appears to be a stimulatory effect on the motor output to upper airway dilator muscles. The purpose of the present study was to determine whether theophylline might have a second mechanism of action, namely that of improving the force and/or endurance of the pharyngeal dilator musculature. Rat sternohyoid muscle strips were studied in vitro and compared to diaphragm strips. The isometric twitch force and twitch kinetics of neither muscle were altered by theophylline (100 mg/l). Theophylline significantly slowed the rate at which the diaphragm fatigued during intermittent 40-Hz stimulation (p < 0.001). In contrast, theophylline produced no improvement in the fatigue resistance of the sternohyoid muscle. The degree of force potentiation during the early portion of the fatigue protocol was not altered by theophylline for either muscle. These results suggest that the mechanism by which theophylline improves obstructive apnea is unlikely to be due to a beneficial effect on pharyngeal dilator muscle force or endurance. PMID:8966372
Laterally Driven Resonant Pressure Sensor with Etched Silicon Dual Diaphragms and Combined Beams
Du, Xiaohui; Liu, Yifang; Li, Anlin; Zhou, Zhou; Sun, Daoheng; Wang, Lingyun
A novel structure of the resonant pressure sensor is presented in this paper, which tactfully employs intercoupling between dual pressure-sensing diaphragms and a laterally driven resonant strain gauge. After the resonant pressure sensor principle is introduced, the coupling mechanism of the diaphragms and resonator is analyzed and the frequency equation of the resonator based on the triangle geometry theory is developed for this new coupling structure. The finite element (FE) simulation results match the theoretical analysis over the full scale of the device. This pressure sensor was first fabricated by dry/wet etching and thermal silicon bonding, followed by vacuum-packaging using anodic bonding technology. The test maximum error of the fabricated sensor is 0.0310%F.S. (full scale) in the range of 30 to 190 kPa, its pressure sensitivity is negative and exceeding 8 Hz/kPa, and its Q-factor reaches 20,000 after wafer vacuum-packaging. A novel resonant pressure sensor with high accuracy is presented in this paper. PMID:26821031
Vibrational mode and sound radiation of electrostatic speakers using circular and annular diaphragms
NASA Astrophysics Data System (ADS)
Huang, Yu-Hsi; Chiang, Hsin-Yuan
This study modeled two diaphragms comprising a pair of indium tin oxide (ITO) transparent plates sandwiching a vibrating diaphragm to create circular (30 mm radius) and annular (30 mm outer and 3 mm inner radius) push-pull electrostatic speakers. We then measured the displacement amplitudes and mode shapes produced by the devices. Vibration characteristics were used to predict sound pressure levels (SPLs) using the lumped parameter method (LPM) and distributed parameter method (DPM). The two measurement results obtained using a laser system were compared to the SPLs obtained using traditional acoustic measurement (AM) from 20 Hz to 20 kHz in order to verify our predictions. When using LPM and DPM, the SPL prediction results in the first three symmetric modes were in good agreement with the AM results. Under the assumption of linear operations, the DPM and amplitude-fluctuation electronic speckle pattern interferometry (ESPI) techniques proved effective in determining the visualization of mode shape (0,1)-(0,3). The use of ITO plates is a practical technique for the prediction of SPL, as well as measurement of mode shapes. The four evaluation methods, i.e. LPM, DPM, ESPI and AM, present a high degree of consistency with regard to vibrational mode and sound radiation characteristics.
Nitric oxide donors improve prednisone effects on muscular dystrophy in the mdx mouse diaphragm.
Mizunoya, Wataru; Upadhaya, Ritika; Burczynski, Frank J; Wang, Guqi; Anderson, Judy E
In Duchenne muscular dystrophy (DMD), palliative glucocorticoid therapy can produce myopathy or calcification. Since increased nitric oxide synthase activity in dystrophic mice promotes regeneration, the outcome of two nitric oxide (NO) donor drugs, MyoNovin (M) and isosorbide dinitrate (I), on the effectiveness of the anti-inflammatory drug prednisone (P) in alleviating progression of dystrophy was tested. Dystrophic mdx mice were treated (18 days) as controls or with an NO donor ± P. Fiber permeability and DNA synthesis were labeled by Evans blue dye (EBD) and bromodeoxyuridine uptake, respectively. P decreased body weight gain, M increased quadriceps mass, and I increased heart mass. P increased fiber permeability (%EBD+ fibers) and calcification in diaphragm. Treatment with NO donors + P (M+P, I+P) reduced %EBD+ fibers and calcification vs. P alone. %EBD+ fibers in M+P diaphragm did not differ from control. NO donor treatment reduced proliferation and the population of c-met+ cells and accelerated fiber regeneration. Concurrent with P, NO donor treatment suppressed two important detrimental effects of P in mice, possibly by accelerating regeneration, rebalancing satellite cell quiescence and activation in dystrophy, and/or increasing perfusion. Results suggest that NO donors could improve current therapy for DMD. PMID:21270295
Systemic amyloidosis involving the diaphragm and acute massive hydrothorax during peritoneal dialysis.
Gagnon, R F; Thirlweil, M; Arzoumanian, A; Mehio, A
Hydrothorax secondary to trans-diaphragmatic fluid leakage through a peritoneo-pleural communication is an occasional, potentially serious complication of peritoneal dialysis. The etiology of this condition is not clear, being thought to be due either to congenital or acquired diaphragmatic fenestrations or acquired scarcity of muscle fibers in the tendinous part of the diaphragm which are compounded by increased intra-abdominal pressure during the dwell period of peritoneal dialysis. We report a 54-year-old woman who developed irreversible acute renal failure from adjuvant chemotherapy for ovarian cancer previously resected surgically. Three days after the onset of continuous ambulatory peritoneal dialysis, she developed acute respiratory distress associated with a massive right hydrothorax secondary to a peritoneo-pleural communication demonstrated by scintigraphy. At autopsy 2 weeks later, systemic amyloidosis was surprisingly found and histologic examination of the right hemidiaphragm showed the presence of amyloid, among sparse muscle fibers. This is the first case report of a distinct pathological process, i.e. amyloidosis, involving the diaphragm associated with a peritoneo-pleural communication causing massive hydrothorax at the onset of peritoneal dialysis. PMID:12078953
Evaluation of glued-diaphragm fibre optic pressure sensors in a shock tube
NASA Astrophysics Data System (ADS)
Sharifian, S. Ahmad; Buttsworth, David R.
Glued-diaphragm fibre optic pressure sensors that utilize standard telecommunications components which are based on Fabry-Perot interferometry are appealing in a number of respects. Principally, they have high spatial and temporal resolution and are low in cost. These features potentially make them well suited to operation in extreme environments produced in short-duration high-enthalpy wind tunnel facilities where spatial and temporal resolution are essential, but attrition rates for sensors are typically very high. The sensors we consider utilize a zirconia ferrule substrate and a thin copper foil which are bonded together using an adhesive. The sensors show a fast response and can measure fluctuations with a frequency up to 250 kHz. The sensors also have a high spatial resolution on the order of 0.1 mm. However, with the interrogation and calibration processes adopted in this work, apparent errors of up to 30% of the maximum pressure have been observed. Such errors are primarily caused by mechanical hysteresis and adhesive viscoelasticity. If a dynamic calibration is adopted, the maximum measurement error can be limited to about 10% of the maximum pressure. However, a better approach is to eliminate the adhesive from the construction process or design the diaphragm and substrate in a way that does not require the adhesive to carry a significant fraction of the mechanical loading.
Tidal volume and diaphragm muscle activity in rats with cervical spinal cord injury.
Imagita, Hidetaka; Nishikawa, Akira; Sakata, Susumu; Nishii, Yasue; Minematsu, Akira; Moriyama, Hideki; Kanemura, Naohiko; Shindo, Hanae
[Purpose] The purpose of this study was to make an experimental model of cervical spinal cord injury (CSCI) using Wistar rats, in order to analyze the influence of CSCI on the respiratory function. [Subjects] Thirty-two male 12-week-old Wistar rats were used. [Methods] The CSCI was made at the levels from C3 to C7, and we performed pneumotachography and electromyography (EMG) on the diaphragm. Computed tomography was used to determine the level of spinal cord damage. [Results] After the operation, the tidal volume of the rats with a C3 level injury decreased to approximately 22.3% of its pre-injury value. In addition, in the same rats, the diaphragmatic electromyogram activity decreased remarkably. Compared with before CSCI, the tidal volume decreased to 78.6% of its pre-injury value in CSCI at the C5 level, and it decreased to 94.1% of its pre-injury value in CSCI at the C7 level. [Conclusion] In the rats that sustained a CSCI in this study, the group of respiratory muscles that receive innervation from the thoracic spinal cord was paralyzed. Therefore, the EMG signal of the diaphragm increased. These results demonstrate that there is a relationship between respiratory function and the level of CSCI. PMID:25931732
Altered activation of the diaphragm in late-onset Pompe disease.
Smith, Barbara K; Corti, Manuela; Martin, A Daniel; Fuller, David D; Byrne, Barry J
Pompe disease is an inherited neuromuscular disorder that affects respiratory function and leads to dependence on external ventilatory support. We studied the activation of the diaphragm using bilateral phrenic magnetic stimulation and hypothesized that diaphragm compound muscle action potential (CMAP) amplitude and evoked transdiaphragmatic pressure (Twitch PDI) would correlate to disease severity. Eight patients with late onset Pompe disease (LOPD, aged 14-48 years) and four healthy control subjects completed the tests. Maximal Twitch PDI responses were progressively reduced in patients with LOPD compared to control subjects (1.4-17.1cm H2O, p<0.001) and correlated to voluntary functional tests (p<0.05). Additionally, CMAP amplitude (mA) was lower in the patients who used nighttime or fulltime ventilatory support, when compared to controls and patients who used no ventilatory support (p<0.005). However, the normalized (%peak) Twitch PDI and CMAP responses were similar between patients and controls. This suggests a loss of functional phrenic motor units in patients, with normal recruitment of remaining motor units. PMID:26612101
Ultrasonic diaphragm tracking for cardiac interventional navigation on 3D motion compensated static roadmaps
NASA Astrophysics Data System (ADS)
Timinger, Holger; Kruger, Sascha; Dietmayer, Klaus; Borgert, Joern
In this paper, a novel approach to cardiac interventional navigation on 3D motion-compensated static roadmaps is presented. Current coronary interventions, e.g. percutaneous transluminal coronary angioplasties, are performed using 2D X-ray fluoroscopy. This comes along with well-known drawbacks like radiation exposure, use of contrast agent, and limited visualization, e.g. overlap and foreshortening, due to projection imaging. In the presented approach, the interventional device, i.e. the catheter, is tracked using an electromagnetic tracking system (MTS). Therefore, the catheters position is mapped into a static 3D image of the volume of interest (VOI) by means of an affine registration. In order to compensate for respiratory motion of the catheter with respect to the static image, a parameterized affine motion model is used which is driven by a respiratory sensor signal. This signal is derived from ultrasonic diaphragm tracking. The motion compensation for the heartbeat is done using ECG-gating. The methods are validated using a heart- and diaphragm-phantom. The mean displacement of the catheter due to the simulated organ motion decreases from approximately 9 mm to 1.3 mm. This result indicates that the proposed method is able to reconstruct the catheter position within the VOI accurately and that it can help to overcome drawbacks of current interventional procedures.
Phenol degradation by a nonpulsed diaphragm glow discharge in an aqueous solution.
Liu, Yong Jun; Jiang, Xuan Zhen
In the present study, a nonpulsed direct current diaphragm glow discharge process was developed for the first time for phenol degradation in an aqueous solution. The discharge was generated in a small hole in a dielectric diaphragm interposed between two submersed graphite electrodes. The experimental results revealed that supplied voltage, initial pH, iron salts, and radical scavengers impact the phenol degradation significantly. Enhancing the applied voltage, lowering the solution pH, and adding appropriate amounts of Fe2+ or Fe3+ to the solution were found to be favorable for phenol degradation. Carbonate ions or n-butanol in the solution can decelerate the phenol removal. When the treatment time is increased, the pH value of the solution decreased, leading to an increase in the phenol decomposition. It was revealed by high performance liquid chromatography and ionic chromatography that the main intermediates of phenol decomposition are hydroquinone, pyrocatechol, p-benzoquinone and organic acids. In comparison with the high-voltage corona discharge plasma in distilled water, this process offers simple technology, higher energy efficiency, easier scaleup, and easier applicability to salt-containing wastewater with no electrode erosion and electromagnetic radiation. PMID:16294895
Effects of sustained hypoxia on sternohyoid and diaphragm muscle during development.
Carberry, Jayne C; McMorrow, Clodagh; Bradford, Aidan; Jones, James F X; O'Halloran, Ken D
Sustained hypoxia is a dominant feature of respiratory disease. Despite the clinical significance, the effects of sustained hypoxia on the form and function of respiratory muscle during development are relatively underexplored. Wistar rats were exposed to 1 week of sustained hypoxia (ambient pressure 450 mmHg) or normoxia at various time points during development. Sternohyoid and diaphragm muscle contractile and endurance properties were assessed in vitro. Muscle succinate dehydrogenase and myosin heavy chain composition were determined. The role of reactive oxygen species in hypoxia-induced muscle remodelling was assessed. Sustained hypoxia increased sternohyoid muscle force and fatigue in early but not late development, effects that persisted after return to normoxia. Hypoxia-induced sternohyoid muscle fatigue was not attributable to fibre type transitions or to a decrease in oxidative capacity. Chronic supplementation with the superoxide scavenger tempol did not prevent hypoxia-induced sternohyoid muscle fatigue, suggesting that mechanisms unrelated to oxidative stress underpin hypoxia-induced maladaptation in sternohyoid muscle. Sustained hypoxia had no effect on diaphragm muscle fatigue. We conclude that there are critical windows during development for hypoxia-induced airway dilator muscle maladaptation. Sustained hypoxia-induced impairment of upper airway muscle endurance may persist into later life. Upper airway muscle dysfunction could have deleterious consequences for the control of pharyngeal airway calibre in vivo. PMID:23766332
Changes in contractile properties of skinned single rat soleus and diaphragm fibres after chronic hypoxia.
Degens, Hans; Bosutti, Alessandra; Gilliver, Sally F; Slevin, Mark; van Heijst, Arno; Wüst, Rob C I
Hypoxia may be one of the factors underlying muscle dysfunction during ageing and chronic lung and heart failure. Here we tested the hypothesis that chronic hypoxia per se affects contractile properties of single fibres of the soleus and diaphragm muscle. To do this, the force-velocity relationship, rate of force redevelopment and calcium sensitivity of single skinned fibres from normoxic rats and rats exposed to 4 weeks of hypobaric hypoxia (410 mmHg) were investigated. The reduction in maximal force (P(0)) after hypoxia (p=0.031) was more pronounced in type IIa than type I fibres and was mainly attributable to a reduction in fibre cross-sectional area (p=0.044). In type IIa fibres this was aggravated by a reduction in specific tension (p=0.001). The maximal velocity of shortening (V (max)) and shape of the force velocity relation (a/P(0)), however, did not differ between normoxic and hypoxic muscle fibres and the reduction in maximal power of hypoxic fibres (p=0.012) was mainly due to a reduction in P(0). In conclusion, chronic hypoxia causes muscle fibre dysfunction which is not only due to a loss of muscle mass, but also to a diminished force generating capacity of the remaining contractile material. These effects are similar in the soleus and diaphragm muscle, but more pronounced in type IIa than I fibres. PMID:20697736
Error-based autofocus system using image feedback in a liquid-filled diaphragm lens
NASA Astrophysics Data System (ADS)
Abdullah, Soran J.; Ratnam, Mani Maran; Samad, Zahurin
A liquid-filled diaphragm (LFD) lens system that uses image feedback for automatic focus control has been designed and developed. The edge slope width (ESW) of the pixel intensity profile across a binary target was selected as the focus measure parameter. An algorithm was developed to achieve single- and dual-direction autofocus control. An improved autofocus method, which is based on the error between the expected ESW value for a focused image and the ESW value for the current (unfocused) image, was introduced to improve the performance of the system. An empirical equation of the focus measure error was used to predict the number of autofocus operation steps required to approach a near-focus region. A stepper motor was used for actuating a syringe-driven pump mechanism that injects or withdraws fluid into (or out of) the fluid lens chamber. The lens diaphragm was made of polydimethylsiloxane (PDMS) polymer that covers the fluid chamber. A monochrome CCD camera was attached to the LFD lens to capture live images of the target. The autofocus experiments carried out using the new differential error-based algorithm proved the viability of the algorithm in determining the near-focus region. A maximum reduction of time operation was also recorded to be 40 s in comparison with the normal autofocus algorithm.
Prevalence Rates of Uterine Cervical Carcinoma in situ for Women Using the Diaphragm or Contraceptive Oral Steroids*
Melamed, Myron R.; Koss, Leopold G.; Flehinger, Betty J.; Kelisky, Richard P.; Dubrow, Hilliard
Study of the prevalence rates of uterine cervical carcinoma in situ among women attending centres of Planned Parenthood of New York City, Inc., showed a small but statistically significant difference between the population choosing and using the diaphragm and the population choosing and using oral steroids for contraception. This can be attributed either to a decreased prevalence rate for women using the diaphragm or to an increased rate for women using oral steroids. The reason for the difference is not apparent from these data. PMID:5792609
Autophagy-Associated Atrophy and Metabolic Remodeling of the Mouse Diaphragm after Short-Term Intermittent Hypoxia
Giordano, Christian; Lemaire, Christian; Li, Tong; Kimoff, R. John; Petrof, Basil J.
Background Short-term intermittent hypoxia (IH) is common in patients with acute respiratory disorders. Although prolonged exposure to hypoxia induces atrophy and increased fatigability of skeletal muscle, the response to short-term IH is less well known. We hypothesized that the diaphragm and limb muscles would adapt differently to short-term IH given that hypoxia stimulates ventilation and triggers a superimposed exercise stimulus in the diaphragm. Methods We determined the structural, metabolic, and contractile properties of the mouse diaphragm after 4 days of IH (8 hours per day, 30 episodes per hour to a FiO2 nadir=6%), and compared responses in the diaphragm to a commonly studied reference limb muscle, the tibialis anterior. Outcome measures included muscle fiber size, assays of muscle proteolysis (calpain, ubiquitin-proteasome, and autophagy pathways), markers of oxidative stress and mitochondrial function, quantification of intramyocellular lipid and lipid metabolism genes, type I myosin heavy chain (MyHC) expression, and in vitro contractile properties. Results After 4 days of IH, the diaphragm alone demonstrated significant atrophy (30% decrease of myofiber size) together with increased LC3B-II protein (2.4-fold) and mRNA markers of the autophagy pathway (LC3B, Gabarapl1, Bnip3), whereas active calpain and E3 ubiquitin ligases (MuRF1, atrogin-1) were unaffected in both muscles. Succinate dehydrogenase activity was significantly reduced by IH in both muscles. However, only the diaphragm exhibited increased intramyocellular lipid droplets (2.5-fold) after IH, along with upregulation of genes linked to activated lipid metabolism. In addition, although the diaphragm showed evidence for acute fatigue immediately following IH, it underwent an adaptive fiber type switch toward slow type I MyHC-expressing fibers, associated with greater intrinsic endurance of the muscle during repetitive stimulation in vitro. Conclusions Short-term IH induces preferential atrophy
Quantification of the Variability of Diaphragm Motion and Implications for Treatment Margin Construction
Rit, Simon; Herk, Marcel van; Zijp, Lambert; Sonke, Jan-Jakob
Purpose: To quantify the variability of diaphragm motion during free-breathing radiotherapy of lung patients and its effect on treatment margins to account for geometric uncertainties. Methods and Materials: Thirty-three lung cancer patients were analyzed. Each patient had 5-19 cone-beam scans acquired during different treatment fractions. The craniocaudal position of the diaphragm dome on the same side as the tumor was tracked over 2 min in the projection images, because it is both easily visible and a suitable surrogate to study the variability of the tumor motion and its impact on treatment margins. Intra-acquisition, inter-acquisition, and inter-patient variability of the respiratory cycles were quantified separately, as were the probability density functions (PDFs) of the diaphragm position over each cycle, each acquisition, and each patient. Asymmetric margins were simulated using each patient PDF and compared to symmetric margins computed from a margin recipe. Results: The peak-to-peak amplitude variability (1 SD) was 3.3 mm, 2.4 mm, and 6.1 mm for the intra-acquisition, inter-acquisition, and inter-patient variability, respectively. The average PDF of each cycle was similar to the sin{sup 4} function but the PDF of each acquisition was closer to a skew-normal distribution because of the motion variability. Despite large interfraction baseline variability, the PDF of each patient was generally asymmetric with a longer end-inhale tail because the end-exhale position was more stable than the end-inhale position. The asymmetry of the PDF required asymmetric margins around the time-averaged position to account for the position uncertainty but the average difference was 1.0 mm (range, 0.0-4.4 mm) for a sharp penumbra and an idealized online setup correction protocol. Conclusion: The respiratory motion is more irregular during the fractions than between the fractions. The PDF of the respiratory motion is asymmetrically distributed. Both the intra
Artificial pleural effusion in percutaneous microwave ablation of hepatic tumors near the diaphragm under the guidance of ultrasound
Wang, Gang; Sun, Yao; Cong, Lin; Jing, Xuehong; Yu, Jing
Objective: To evaluate the feasibility, safety and efficacy of artificial pleural effusion in percutaneous microwave ablation of hepatic tumors near the diaphragm under ultrasound guidance. Methods: For localization and navigation of tumors near the dome of the diaphragm by ultrasound during microwave ablation in 14 tumors of 11 cases, artificial pleural effusion was performed in the volume of 1000~1500 ml of Normal saline or 5% Glucose injection solution via the right thoracic cavity. The tumor marker, AFP was monitored before and after operation in 6 times in a period of 2 years. We analyzed the successful rate and effectiveness of artificial pleural effusion. Results: The successful rate of artificial pleural effusion was 100% without complications. Artificial hydrothorax on the right eliminated the interference of intrapulmonary gas to the visualization of hepatic tumors near the diaphragm on ultrasound. In the follow-up of 2 years, the ablation rate reached to 92.9% with no serious complications. The AFP value before operation was in significant statistical difference with the others after operation (P = 0.000). Conclusions: Artificial pleural effusion aids the visualization of hepatic tumors near the diaphragm on ultrasound. A good therapeutic effectiveness can be reached in percutaneous microwave ablation of tumors in the hepatic dome under the guidance of ultrasound. PMID:26629218
Kif7 is required for the patterning and differentiation of the diaphragm in a model of syndromic congenital diaphragmatic hernia
Coles, Garry L.; Ackerman, Kate G.
Congenital diaphragmatic hernia (CDH) is a common birth defect that results in a high degree of neonatal morbidity and mortality, but its pathological mechanisms are largely unknown. Therefore, we performed a forward genetic screen in mice to identify unique genes, models, and mechanisms of abnormal diaphragm development. We identified a mutant allele of kinesin family member 7 (Kif7), the disorganized diaphragm (dd). Embryos homozygous for the dd allele possess communicating diaphragmatic hernias, central tendon patterning defects, and increased cell proliferation with diaphragmatic tissue hyperplasia. Because the patterning of the central tendon is undescribed, we analyzed the expression of genes regulating tendonogenesis in dd/dd mutant embryos, and we determined that retinoic acid (RA) signaling was misregulautted. To further investigate the role of Kif7 and RA signaling in the development of the embryonic diaphragm, we established primary mesenchymal cultures of WT embryonic day 13.5 diaphragmatic cells. We determined that RA signaling is necessary for the expression of tendon markers as well as the expression of other CDH-associated genes. Knockdown of Kif7, and retinoic acid receptors alpha (Rara), beta (Rarb), and gamma (Rarg) indicated that RA signaling is dependent on these genes to promote tendonogenesis within the embryonic diaphragm. Taken together, our results provide evidence for a model in which inhibition of RA receptor signaling promotes CDH pathogenesis through a complex gene network. PMID:23650387
Creation of coronary sinus using left atrial diaphragm in the patient with cor triatriatum and unroofed coronary sinus.
Nakano, Kiyoharu; Ayusawa, Keiich; Gome, Akihiko; Nakatani, Hayao; Nakamura, Yositsugu; Sughimoto, Koich; Sato, Atsuhiko
Surgical correction of cor triatriatum with unroofed coronary sinus consisted of creation of the coronary sinus using the left atrial diaphragm and closure of the atrial septal defect in an adult patient. No materials other than intracardiac components were used to repair all anomalies. PMID:16631701
Systematic distribution of muscle fibre types in the rat and rabbit diaphragm: a morphometric and ultrastructural analysis.
Kilarski, W; Sjöström, M
The histochemical and ultrastructural characteristics of the adult rat and rabbit costal diaphragm were investigated. On the basis of enzyme histochemistry, the rat diaphragm was found to contain 42% and 39% Type I, 24% and 25% Type II A and 33% and 34% Type II B fibres on the thoracic and abdominal surfaces respectively. The rabbit costal diaphragm contained 18% and 26% Type I, 46% and 39% Type II A and 35% and 34% Type II B fibres on the thoracic and abdominal surfaces respectively. Differences in the proportion of each muscle fibre type were also observed between diaphragmatic regions (ventral, medial and dorsal) in the rat as well as in the rabbit. Differences in muscle architecture were also noted on the basis of stereological analysis in estimation of volume density, surface density, numerical density and cross-sectional areas of each muscle fibre type. The fine structural analysis of all three fibre types also showed significant differences in the width of the A-bands and Z-lines between the muscle fibre types of the rat and rabbit costal diaphragm. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:2139020
Specific and artifactual labeling in the rat spinal cord and medulla after injection of monosynaptic retrograde tracers into the diaphragm.
Boulenguez, Pascale; Gestreau, Christian; Vinit, Stéphane; Stamegna, Jean-Claude; Kastner, Anne; Gauthier, Patrick
The use of fluorescent dyes has been a major improvement for paths tracing studies. However, these tracers present different properties and have to be chosen carefully. The present study compares the ability of different tracers to specifically label phrenic motoneurons (PMNs) innervating the rat diaphragm. The administration of fluorogold (FG) from the transected phrenic nerve specifically labeled PMNs in the ipsilateral spinal cord. However, when FG was injected into one hemidiaphragm, in addition with ipsilateral PMNs, a less intense artifactual labeling was observed in the spinal cord (mainly in contralateral PMNs) and in the medulla oblongata (mainly in the area postrema and cranial motor nuclei). Similar results were observed using horseradish peroxidase, while no labeling was observed after injection of nuclear yellow or diamidino yellow into the diaphragm. By contrast, the dextran amine fluororuby (FR) and the carbocyanine DiAsp selectively and exclusively labeled ipsilateral PMNs 2 or 3 weeks after injection into the diaphragm, respectively. The lipophilic properties of DiAsp and the high molecular weight of FR may prevent their diffusion to adjacent tissues and into the blood stream which seems to account for the artifactual labeling observed with the other tracers. The higher homogeneity and quality of the labeling observed with FR compared to DiAsp make it the most appropriate tracer for the specific monosynaptic fluorescent labeling of PMNs after injection into the diaphragm. PMID:17412505
A New Analytical Solution for Diaphragm Deflection and its Application to a Surface-Micromachined Pressure Sensor
Bitsie, F.; Eaton, W.P.; Plummer, D.W.; Smith, J.H.
An analytical solution for large deflections of a clamped circular diaphragm with built-in stress is presented. The solution is directly applicable to micromachined pressure sensors. The solution is compared to finite element analysis results and experimental data from a surface-micromachined pressure sensor.
Fabrication of MEMS ZnO dome-shaped-diaphragm transducers for high-frequency ultrasonic imaging
NASA Astrophysics Data System (ADS)
Feng, Guo-Hua; Sharp, Charles C.; Zhou, Q. F.; Pang, Wei; Sok Kim, Eun; Shung, K. K.
This paper presents the microfabrication technique for a dome-shaped-diaphragm transducer (DSDT) for 200 MHz cellular microstructure imaging. The DSDT uses piezoelectric ZnO film to generate acoustic waves, and is fabricated on a silicon substrate. The fabricated DSDTs have been tested with a pulse-echo method using a quartz target, and shown to produce an echo signal at 210 MHz with 20% bandwidth. The DSDT fabrication uses spherical balls to precisely shape wax molds, onto which parylene is deposited as a support layer for the DSDT. The wax molds are removed by toluene to release the parylene dome diaphragms. Piezoelectric ZnO film is sputter deposited on the parylene dome diaphragm. E-Solder silver epoxy is placed and cured on the back surface to function both as an acoustic backing and as structural support. Quarter wavelength thick parylene is deposited on the front side of the wafer for acoustic matching. The fabrication technique for the DSDTs is meant for low-cost mass production of the devices for high-frequency biomedical imaging. Moreover, the technique allows the precise control of the radius and curvature of the dome-shaped diaphragm through adjusting the size of the front-to-backside thru holes using different radii of the spherical balls.
Mullenhoff, D.J.; Johnston, B.C.; Azevedo, S.G.
A report is made on the demonstration of a first-generation Wall Surveyor that is capable of surveying the interior and thickness of a stone, brick, or cement wall. LLNL`s Micropower Impulse Radar is used, based on emitting and detecting very low amplitude and short microwave impulses (MIR rangefinder). Six test walls were used. While the demonstrator MIR Wall Surveyor is not fieldable yet, it has successfully scanned the test walls and produced real-time images identifying the walls. It is planned to optimize and package the evaluation wall surveyor into a hand held unit.
NASA Technical Reports Server (NTRS)
Newman, Perry A.; Mineck, Raymond E.; Barnwell, Richard W.; Kemp, William B., Jr.
About a decade ago, interest in alleviating wind tunnel wall interference was renewed by advances in computational aerodynamics, concepts of adaptive test section walls, and plans for high Reynolds number transonic test facilities. Selection of NASA Langley cryogenic concept for the National Transonic Facility (NTF) tended to focus the renewed wall interference efforts. A brief overview and current status of some Langley sponsored transonic wind tunnel wall interference research are presented. Included are continuing efforts in basic wall flow studies, wall interference assessment/correction procedures, and adaptive wall technology.
NASA Technical Reports Server (NTRS)
Braam, J.; McIntire, L. V. (Principal Investigator)
The plant cell wall is very complex, both in structure and function. The wall components and the mechanical properties of the wall have been implicated in conveying information that is important for morphogenesis. Proteoglycans, fragments of polysaccharides and the structural integrity of the wall may relay signals that influence cellular differentiation and growth control. Furthering our knowledge of cell wall structure and function is likely to have a profound impact on our understanding of how plant cells communicate with the extracellular environment.
Conformal piezoelectric energy harvesting and storage from motions of the heart, lung, and diaphragm
Dagdeviren, Canan; Yang, Byung Duk; Su, Yewang; Tran, Phat L.; Joe, Pauline; Anderson, Eric; Xia, Jing; Doraiswamy, Vijay; Dehdashti, Behrooz; Feng, Xue; Lu, Bingwei; Poston, Robert; Khalpey, Zain; Ghaffari, Roozbeh; Huang, Yonggang; Slepian, Marvin J.; Rogers, John A.
Here, we report advanced materials and devices that enable high-efficiency mechanical-to-electrical energy conversion from the natural contractile and relaxation motions of the heart, lung, and diaphragm, demonstrated in several different animal models, each of which has organs with sizes that approach human scales. A cointegrated collection of such energy-harvesting elements with rectifiers and microbatteries provides an entire flexible system, capable of viable integration with the beating heart via medical sutures and operation with efficiencies of ∼2%. Additional experiments, computational models, and results in multilayer configurations capture the key behaviors, illuminate essential design aspects, and offer sufficient power outputs for operation of pacemakers, with or without battery assist. PMID:24449853
Electro-elastic modeling of a dielectric elastomer diaphragm for a prosthetic blood pump
NASA Astrophysics Data System (ADS)
Goulbourne, Nakhiah C.; Frecker, Mary I.; Mockensturm, Eric
A dielectric elastomer diaphragm is to be designed for potential use in a prosthetic blood pump. Application of an electric field deforms the membrane such that it moves from an initially flat configuration to an inflated state. This motion creates positive displacement of blood from the cardiac chambers thus mimicking the pump-like behavior of the natural heart. A comprehensive large deformation model accounting for the combined dielectric and elastic effect has been formulated. This paper presents recent developments in the model to further incorporate the entire nonlinear range of material elastic behavior and to more accurately represent the applied electric field by keeping the voltage constant as the membrane thickness decreases. The updated model is used to calculate the effects of varying system parameters such as pressure, voltage, prestretch, material constants, and membrane geometry. Analytical results are obtained for biaxially stretched 3M VHB 4905 polyacrylate films.
Active buckling control of smart plate as diaphragm with PZT5 sensor/actuator patches
NASA Astrophysics Data System (ADS)
Viliani, N. S.; Pourrostami, H.; Mostafavi, S. M.; Hashemizadeh, F.; Safian, M. R.; Hashemi, M.
In current study, buckling analyses of smart plate is presented. The various types of piezoelectric materials are under investigation for petrochemical industry and other applications. The PZT sensor output is used to determine the input to the PZT actuator using the feedback control algorithm for buckling control of FG plate. This study investigated the governing differential equations of motion of smart plate which includes FG plate as the membrane and PZT5 patches as actuator and sensor. The Fourier series method adopted to obtain the solution for the equation of motion. Also the effects of feedback gain and FGM volume fraction exponent on the critical buckling load for PZT-5A are studied. The potential application of current study can be found in optimal design of sensor's diaphragm. The variation of critical buckling load vs. feedback gain indicates that by increasing the feedback gain, the buckling load increases.
A High-speed Engine Pressure Indicator of the Balanced Diaphragm Type
NASA Technical Reports Server (NTRS)
Dickinson, H C; Newell, F B
This report describes a pressure-measuring device especially adapted for use in mapping indicator diagrams of high-speed internal combustion engines. The cards are obtained by a point-to-point method giving the average of a large number of engine cycles. The principle involved is the balancing of the engine cylinder pressure against a measured pressure on the opposite side of the metal a diaphragm of negligible stiffness. In its application as an engine indicator the phase of the engine cycle to which a pressure measurement corresponds is selected by a timing device. The report discusses briefly the errors which must be avoided in the development of an indicator for light high-speed engines, where vibration is serious, and outlines the principles underlying the design of this instrument in order to be free of such errors. A detailed description of the instrument and accessories follows together with operating directions.
Diaphragm-free fiber-optic Fabry-Perot interferometer based on tapered hollow silica tube
NASA Astrophysics Data System (ADS)
Fang, Guocheng; Jia, Pinggang; Liang, Ting; Tan, Qiulin; Hong, Yingping; Liu, Wenyi; Xiong, Jijun
A miniature fiber-optic Fabry-Perot interferometer fabricated by splicing a diaphragm-free hollow silica tube to a single-mode fiber and fusing the inner core to a taper is presented. The tapered zone forces lights to propagate from the fiber core into the silica tube, and the lights is reflected from the end faces of the optical fiber and the hollow silica tube. The contrast ratio of the interference fringe is determined by the minimum inner diameter of hollow silica tube. The responses of the proposed interferometer to high-temperature, gas refractive index, liquid refractive index and pressure were measured and were found to be linear with sensitivities of 16.26 pm/°C, 610.47 nm/RIU, -122.36 dB/RIU and 1.56 pm/kPa, respectively.
Laparoscopic repair of diaphragm perforation with heart patch after microwave ablation
Liang, Qing-Chen; Tian, Yan-Jie; Xiao-Jiang, Ting
Microwave ablation (MWA) is a new technology developed in recent years, which is widely used in various disciplines. Microwave ablation is an alternative to surgery in the management of various tumors, and it has been demonstrated to be effective in the management of primary tumors and metastatic tumors. Microwave ablation is widely used in the treatment of hepatocellular carcinoma with an obvious effect and less side effects, and only 2.7% had serious complications. Many studies have confirmed the complications are thermal damage, hemorrhage, pleural effusion, bile leak, tumor seeding, hepatic abscess, cholangitis, and so forth. But diaphragm perforation is rare, and it is probably the first case reported. This article describes diaphragmatic perforation secondary to MWA of the liver with subsequent pleural effusion and diaphragmatic hernia. We also describe its management via the laparoscopic approach. PMID:26905357
Experimental and Analytical Study of Balanced-Diaphragm Fuel Distributors for Gas-Turbine Engines
NASA Technical Reports Server (NTRS)
Straight, David M.; Gold, Harold
A method of distributing fuel equally to a plurality of spray nozzles in a gas-turbine engine by means of balanced-diaphragm fuel distributors is presented. The experimental performance of three of eight possible distributor arrangements are discussed. An analysis of all eight arrangements is included. Criterions are given for choosing a fuel-distributor arrangement to meet specific fuel-system requirements of fuel-distribution accuracy, spray-nozzle pressure variations, and fuel-system pressures. Data obtained with a model of one distributor arrangement indicated a maximum deviation from perfect distribution of 3.3 percent for a 44 to 1 range (19.5 to 862 lb/hr) of fuel-flow rates. The maximum distributor pressure drop was 125 pounds per square inch. The method used to obtain the required wide range of flow control in the distributor valves consisted in varying the length of a constant-area flow path.
High temperature diaphragm valve-based comprehensive two-dimensional gas chromatography.
Freye, Chris E; Mu, Lan; Synovec, Robert E
A high-temperature diaphragm valve-based comprehensive two-dimensional gas chromatography (GC×GC) instrument is demonstrated which readily allows separations up to 325°C. Previously, diaphragm valve-based GC×GC was limited to 175°C if the valve was mounted in the oven, or limited to 265°C if the valve was faced mounted on the outside of the oven. A new diaphragm valve has been commercially developed, in which the temperature sensitive O-rings that previously limited the separation temperatures have been replaced with Kalrez O-rings, a perfluoroelastomer, allowing for significantly higher temperatures permitting a greater range of volatile and semi-volatile compounds to be readily separated. In the current investigation, a separation temperature up to 325°C is demonstrated with the valve mounted directly in the oven. Since the temperature limit for most commonly used GC columns is at or below 325°C, the scope of diaphragm valve-based GC×GC is now dramatically broadened to encompass a majority of all column stationary phase chemistries. A 44-component mixture of alkanes, alcohols, and polyaromatic hydrocarbons is used to study this new configuration whose boiling points range from 98°C (n-heptane) to 450°C (n-triacontane). For the test mixture using a modulation period PM of 1.0s, peak shapes on second dimension separations, (2)D, are symmetric with average widths at base of 79.4ms, producing a (2)D peak capacity of (2)nc∼12. Based on the average peak width of 2.4s for the first dimension separation with a run time of 32.5min, the (1)D peak capacity is (1)nc∼800. Thus, the ideal two-dimensional peak capacity [Formula: see text] is 9600. Little variation in within-analyte (2)D peak width was observed with an average %RSD of less than 3.0%. Furthermore, retention time on (2)D was very reproducible with an average %RSD less than 0.5%. Measured peak areas (sum of all (2)D peaks for given analyte) had an average %RSD of 4.4%. The transfer fraction from (1)D
Where Did the Water Go? Boyle's Law and Pressurized Diaphragm Water Tanks
NASA Astrophysics Data System (ADS)
Brimhall, James; Naga, Sundar
Many homes use pressurized diaphragm tanks for storage of water pumped from an underground well. These tanks are very carefully constructed to have separate internal chambers for the storage of water and for the air that provides the pressure. One might expect that the amount of water available for use from, for example, a 50-gallon tank would be close to 50 gallons. However, only a surprisingly small percentage of the total tank volume is available to provide water that can be drawn from the tank before the pump must cycle back on. Boyle's law ( PV is constant) provides mathematical insight into the workings of this type of tank, including predictions of the quantities of available water resulting from different initial conditions of the water tank system.
Effects of Gestational and Postnatal Exposure to Chronic Intermittent Hypoxia on Diaphragm Muscle Contractile Function in the Rat.
McDonald, Fiona B; Dempsey, Eugene M; O'Halloran, Ken D
Alterations to the supply of oxygen during early life presents a profound stressor to physiological systems with aberrant remodeling that is often long-lasting. Chronic intermittent hypoxia (CIH) is a feature of apnea of prematurity, chronic lung disease, and sleep apnea. CIH affects respiratory control but there is a dearth of information concerning the effects of CIH on respiratory muscles, including the diaphragm-the major pump muscle of breathing. We investigated the effects of exposure to gestational CIH (gCIH) and postnatal CIH (pCIH) on diaphragm muscle function in male and female rats. CIH consisted of exposure in environmental chambers to 90 s of hypoxia reaching 5% O2 at nadir, once every 5 min, 8 h a day. Exposure to gCIH started within 24 h of identification of a copulation plug and continued until day 20 of gestation; animals were studied on postnatal day 22 or 42. For pCIH, pups were born in normoxia and within 24 h of delivery were exposed with dams to CIH for 3 weeks; animals were studied on postnatal day 22 or 42. Sham groups were exposed to normoxia in parallel. Following gas exposures, diaphragm muscle contractile, and endurance properties were examined ex vivo. Neither gCIH nor pCIH exposure had effects on diaphragm muscle force-generating capacity or endurance in either sex. Similarly, early life exposure to CIH did not affect muscle tolerance of severe hypoxic stress determined ex vivo. The findings contrast with our recent observation of upper airway dilator muscle weakness following exposure to pCIH. Thus, the present study suggests a relative resilience to hypoxic stress in diaphragm muscle. Co-ordinated activity of thoracic pump and upper airway dilator muscles is required for optimal control of upper airway caliber. A mismatch in the force-generating capacity of the complementary muscle groups could have adverse consequences for the control of airway patency and respiratory homeostasis. PMID:27462274
Injury to the diaphragm: Our experience in Union Head quarters Hospital
Radjou, Angeline Neetha; Balliga, Dillip Kumar; Uthrapathy, Muthandavan; Pal, Ranabir; Mahajan, Preetam
Background: Diaphragmatic injury is a global diagnostic and therapeutic challenge. Objectives: The study was to identify the variations in the risk factors, diagnosis, management, and outcome between blunt and penetrating injuries of the diaphragm. Materials and Methods: A prospective study was conducted on patients who were diagnosed with injury to diaphragm during preoperative, intraoperative, or postmortem period. The risk correlates and the trail of events following injury, interventions, and outcomes were studied. Results: Of the 25 cases, blunt injury was experienced by 10. Road traffic injury was the most common cause in blunt trauma and assault with knife in penetrating trauma. Acute presentation was the most common mechanism. X-rays were positive in 52% cases. The most common reason for false negative X-rays was massive effusion/hemothorax. Computed tomography (CT) improved the positivity rate to 62.5%. A total of 25% of diaphragmatic injuries were diagnosed during surgery for hemodynamic instability irrespective of initial X-rays findings. Laprotomy alone was sufficient in majority of cases. The defects were largely in the left side; mean defect size was more in blunt trauma. Associated injuries were noted in 92%. Stomach was most affected in penetrating injuries and spleen in blunt trauma. Empeyma was the most common morbidity. Mortality rate of 13% in penetrating injury was far lower than 60% in blunt injury. Mean Injury Severity Score (ISS) was significantly related to the fatal outcomes irrespective of mechanism. Diagnostic laparoscopy for asymptomatic low velocity junctional penetrating wounds revealed diaphragmatic injury in 20%. Conclusions: The incidence of multisystem injuries at our trauma center is on the rise. A high index of suspicion is needed for diagnosis of diaphragmatic injury. The need for thorough exploratory laprotomy is essential. In resource stretched setting like ours, the need for routine diagnostic laparoscopy in asymptomatic
Exercise Training Prevents TNF-α Induced Loss of Force in the Diaphragm of Mice
Mangner, Norman; Linke, Axel; Oberbach, Andreas; Kullnick, Yvonne; Gielen, Stephan; Sandri, Marcus; Hoellriegel, Robert; Matsumoto, Yasuharu; Schuler, Gerhard; Adams, Volker
Rationale Inflammatory cytokines like tumor necrosis factor alpha (TNF-α) are elevated in congestive heart failure and are known to induce the production of reactive oxygen species as well as to deteriorate respiratory muscle function. Objectives Given the antioxidative effects of exercise training, the aim of the present study was to investigate if exercise training is capable of preventing a TNF-α induced loss of diaphragmatic force in mice and, if so, to elucidate the potential underlying mechanisms. Methods Prior to intraperitoneal injection of TNF-α or saline, C57Bl6 mice were assigned to four weeks of exercise training or sedentary behavior. Diaphragmatic force and power generation were determined in vitro. Expression/activity of radical scavenger enzymes, enzymes producing reactive oxygen species and marker of oxidative stress were measured in the diaphragm. Main Results In sedentary animals, TNF-α reduced specific force development by 42% concomitant with a 2.6-fold increase in the amount of carbonylated α-actin and creatine kinase. Furthermore, TNF-α led to an increased NAD(P)H oxidase activity in both sedentary and exercised mice whereas xanthine oxidase activity and intramitochondrial ROS production was only enhanced in sedentary animals by TNF-α. Exercise training prevented the TNF-α induced force reduction and led to an enhanced mRNA expression and activity of glutathione peroxidase. Carbonylation of proteins, in particular of α-actin and creatine kinase, was diminished by exercise training. Conclusion TNF-α reduces the force development in the diaphragm of mice. This effect is almost abolished by exercise training. This may be a result of reduced carbonylation of proteins due to the antioxidative properties of exercise training. PMID:23300968
Long-term results of diaphragmatic plication in adults with unilateral diaphragm paralysis
Background In this study we aimed to evaluate the long-term outcome of diaphragmatic plication for symptomatic unilateral diaphragm paralysis. Methods Thirteen patients who underwent unilateral diaphragmatic plication (2 patients had right, 11 left plication) between January 2003 and December 2006 were evaluated. One patient died postoperatively due to sepsis. The remaining 12 patients [9 males, 3 females; mean age 60 (36-66) years] were reevaluated with chest radiography, flouroscopy or ultrasonography, pulmonary function tests, computed tomography (CT) or magnetic resonance imaging (MRI), and the MRC/ATS dyspnea score at an average of 5.4 (4-7) years after diaphragmatic plication. Results The etiology of paralysis was trauma (9 patients), cardiac by pass surgery (3 patients), and idiopathic (1 patient). The principle symptom was progressive dyspnea with a mean duration of 32.9 (22-60) months before surgery. All patients had an elevated hemidiaphragm and paradoxical movement radiologically prior to surgery. There were partial atelectasis and reccurent infection of the lower lobe in the affected side on CT in 9 patients. Atelectasis was completely improved in 9 patients after plication. Preoperative spirometry showed a clear restrictive pattern. Mean preoperative FVC was 56.7 ± 11.6% and FEV1 65.3 ± 8.7%. FVC and FEV1 improved by 43.6 ± 30.6% (p < 0.001) and 27.3 ± 10.9% (p < 0.001) at late follow-up. MRC/ATS dyspnea scores improved 3 points in 11 patients and 1 point in 1 patient at long-term (p < 0.0001). Eight patients had returned to work at 3 months after surgery. Conclusions Diaphragmatic plication for unilateral diaphragm paralysis decreases lung compression, ensures remission of symptoms, and improves quality of life in long-term period. PMID:21078140
Lipid intermediates in membrane fusion: formation, structure, and decay of hemifusion diaphragm.
Kozlovsky, Yonathan; Chernomordik, Leonid V; Kozlov, Michael M
Lipid bilayer fusion is thought to involve formation of a local hemifusion connection, referred to as a fusion stalk. The subsequent fusion stages leading to the opening of a fusion pore remain unknown. The earliest fusion pore could represent a bilayer connection between the membranes and could be formed directly from the stalk. Alternatively, fusion pore can form in a single bilayer, referred to as hemifusion diaphragm (HD), generated by stalk expansion. To analyze the plausibility of stalk expansion, we studied the pathway of hemifusion theoretically, using a recently developed elastic model. We show that the stalk has a tendency to expand into an HD for lipids with sufficiently negative spontaneous splay, (~)J(s)< 0. For different experimentally relevant membrane configurations we find two characteristic values of the spontaneous splay. (~)J*(s) and (~)J**(s), determining HD dimension. The HD is predicted to have a finite equilibrium radius provided that the spontaneous splay is in the range (~)J**(s)< (~)J(s)<(~)J*(s), and to expand infinitely for (~)J(s)<(~)J**(s). In the case of common lipids, which do not fuse spontaneously, an HD forms only under action of an external force pulling the diaphragm rim apart. We calculate the dependence of the HD radius on this force. To address the mechanism of fusion pore formation, we analyze the distribution of the lateral tension emerging in the HD due to the establishment of lateral equilibrium between the deformed and relaxed portions of lipid monolayers. We show that this tension concentrates along the HD rim and reaches high values sufficient to rupture the bilayer and form the fusion pore. Our analysis supports the hypothesis that transition from a hemifusion to a fusion pore involves radial expansion of the stalk. PMID:12414697
Functional Changes of Diaphragm Type Shunt Valves Induced by Pressure Pulsation
NASA Astrophysics Data System (ADS)
Lee, Chong-Sun; Suh, Chang-Min; Ra, Young-Shin
Shunt valves used to treat patients with hydrocephalus were tested to investigate influence of pressure pulsation on their flow control characteristics. Our focus was on flow dynamic and functional changes of the small and thin diaphragms in the valves that serve as the main flow control mechanism and are made from silicone elastomer. Firstly, pressure-flow control curves were compared under pulsed and steady flow (without pulsation) conditions. Secondly, functional changes of the valves were tested after a long-term continuous pulsation with a peristaltic pump. Thirdly, flushing procedures selectively conducted by neurosurgeons were simulated with a fingertip pressed on the dome of the valves. As 20cc/hr of flow rate was adjusted at a constant pressure, application of 40mmH2O of pressure pulse increased flow rate through shunt valves more than 60%. As a 90cm length silicone catheter was connected to the valve outlet, increase in the flow rate was substantially reduced to 17.5%. Pressure-flow control characteristics of some valves showed significant changes after twenty-eight days of pressure pulsation at 1.0 Hz under 50.0cc/hr of flow rate. Flushing simulation resulted in temporary decrease in the pressure level. It took three hours to fully recover the normal pressure-flow control characteristics after the flushing. Our results suggest that shunt valves with a thin elastic diaphragm as the main flow control mechanism are sensitive to intracranial pressure pulsation or pressure spikes enough to change their pressure-flow control characteristics.
Unwarranted Administration of Acetylcholinesterase Inhibitors Can Impair Genioglossus and Diaphragm Muscle Function
Eikermann, Matthias; Fassbender, Philipp; Malhotra, Atul; Takahashi, Masaya; Kubo, Shigeto; Jordan, Amy S.; Gautam, Shiva; White, David P.; Chamberlin, Nancy L.
Background It is standard practice to administer a cholinesterase inhibitor (e.g., neostigmine) at the end of a surgical case to reverse suspected effects of neuromuscular blocking agents regardless of whether such residual effects are present. The authors hypothesized that cholinesterase inhibition when given the in absence of neuromuscular blockade (NB) would decrease upper airway dilatory muscle activity and consequently upper airway volume. Methods The authors measured genioglossus and diaphragm electromyograms during spontaneous ventilation in anesthetized, tracheostomized rats before and after administration of neostigmine (0.03, 0.06, or 0.12 mg/kg), after recovery of the train-of-four ratio (quadriceps femoris muscle) to unity after NB (n = 18). For comparison, the authors made the same measurements in rats that had no previous NB (n = 27). In intact anesthetized rats, the authors measured upper airway volume and end-expiratory lung volume by magnetic resonance imaging before and after 0.12 mg/kg neostigmine (n = 9). Results Neostigmine treatment in rats that had fully recovered from NB based on the train-of-four ratio caused dose-dependent decreases in genioglossus electromyogram (to 70.3 = 7.6, 49.2 = 3.2, and 39.7 = 2.3% of control, respectively), decreases in diaphragm electromyogram (to 103.1 ± 6.5, 83.1 ± 4.7, and 68.7 ± 7.3% of control), and decreases in minute ventilation to a nadir value of 79.6 ± 6% of preneostigmine baseline. Genioglossus electromyogram effects were the same when neostigmine was given with no previous NB. Neostigmine caused a decrease in upper airway volume to 83 ± 3% of control, whereas end-expiratory lung volume remained constant. Conclusions The cholinesterase inhibitor neostigmine markedly impairs upper airway dilator volume, genioglossus muscle function, diaphragmatic function, and breathing when given after recovery from vecuronium-induced neuromuscular block. PMID:17893459
Diaphragm Used with Replens Gel and Risk of Bacterial Vaginosis: Results from a Randomized Controlled Trial
Cohen, Craig R.; Cheng, Su-Chun; Shiboski, Stephen; Chipato, Tsungai; Matu, Martin; Mwangi, James; Mutimutema, Monalisa E. S.; Tuveson, Jennifer; Kamba, Mavis; Padian, Nancy; van der Straten, Ariane
Background. Bacterial vaginosis (BV) has been linked to female HIV acquisition and transmission. We investigated the effect of providing a latex diaphragm with Replens and condoms compared to condom only on BV prevalence among participants enrolled in an HIV prevention trial. Methods. We enrolled HIV-seronegative women and obtained a vaginal swab for diagnosis of BV using Nugent's criteria; women with BV (score 7–10) were compared to those with intermediate (score 4–6) and normal flora (score 0–3). During quarterly follow-up visits over 12–24 months a vaginal Gram stain was obtained. The primary outcome was serial point prevalence of BV during followup. Results. 528 participants were enrolled; 213 (40%) had BV at enrollment. Overall, BV prevalence declined after enrollment in women with BV at baseline (OR = 0.4, 95% CI 0.29–.56) but did not differ by intervention group. In the intention-to-treat analysis BV prevalence did not differ between the intervention and control groups for women who had BV (OR = 1.01, 95% CI 0.52–1.94) or for those who did not have BV (OR = 1.21, 95% CI 0.65–2.27) at enrollment. Only 2.1% of participants were treated for symptomatic BV and few women (5–16%) were reported using anything else but water to cleanse the vagina over the course of the trial. Conclusions. Provision of the diaphragm, Replens, and condoms did not change the risk of BV in comparison to the provision of condoms alone. PMID:23133307
Inhibition of the ubiquitin-proteasome pathway does not protect against ventilator-induced accelerated proteolysis or atrophy in the diaphragm
Smuder, Ashley J.; Nelson, W. Bradley; Hudson, Matthew B.; Kavazis, Andreas N.; Powers, Scott K.
Background Mechanical ventilation (MV) is a life-saving intervention in patients with acute respiratory failure. However, prolonged MV results in ventilator-induced diaphragm dysfunction (VIDD), a condition characterized by both diaphragm fiber atrophy and contractile dysfunction. Previous work has shown calpain, caspase-3 and the ubiquitin-proteasome pathway (UPP) are all activated in the diaphragm during prolonged MV. However, while it is established that both calpain and caspase-3 are important contributors to VIDD, the role that the UPP plays in VIDD remains unknown. These experiments tested the hypothesis that inhibition of the UPP will protect the diaphragm against VIDD. Methods We tested this prediction in an established animal model of MV using a highly specific UPP inhibitor, epoxomicin, to prevent MV-induced activation of the proteasome in the diaphragm (n = 8/group). Results Our results reveal that inhibition of the UPP did not prevent ventilator-induced diaphragm muscle fiber atrophy and contractile dysfunction during 12 hours of MV. Also, inhibition of the UPP does not impact MV-induced increases in calpain and caspase-3 activity in the diaphragm. Finally, administration of the proteasome inhibitor did not protect against the MV-induced increases in the expression of the E3 ligases, MuRF1 and atrogin-1/MaFbx. Conclusions Collectively, these results indicate that proteasome activation does not play a required role in VIDD during the first 12 hours of MV. PMID:24681580
Fluidized wall for protecting fusion chamber walls
Maniscalco, J.A.; Meier, W.R.
Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. Produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithiumceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.
Daily acute intermittent hypoxia elicits functional recovery of diaphragm and inspiratory intercostal muscle activity after acute cervical spinal injury
Navarrete-Opazo, A.; Vinit, S; Dougherty, B.J.; Mitchell, G.S.
A major cause of mortality after spinal cord injury is respiratory failure. In normal rats, acute intermittent hypoxia (AIH) induces respiratory motor plasticity, expressed as diaphragm (Dia) and second external intercostal (T2 EIC) long-term facilitation (LTF). Dia (not T2 EIC) LTF is enhanced by systemic adenosine 2A (A2a) receptor inhibition in normal rats. We investigated the respective contributions of Dia and T2 EIC to daily AIH-induced functional recovery of breathing capacity with/without A2a receptor antagonist (KW6002, i.p.) following C2 hemisection (C2HS). Rats received daily AIH (dAIH: 10, 5-min episodes, 10.5% O2; 5-min normoxic intervals; 7 successive days beginning 7 days post-C2HS) or daily normoxia (dNx) with/without KW6002, followed by weekly (reminder) presentations for 8 weeks. Ventilation and EMGs from bilateral diaphragm and T2 EIC muscles were measured with room air breathing (21% O2) and maximum chemoreceptor stimulation (MCS: 7% CO2, 10.5% O2). dAIH increased tidal volume (Vt) in C2HS rats breathing room air (dAIH + vehicle: 0.47 ± 0.02, dNx + vehicle: 0.40 ± 0.01ml/100 g; p<0.05) and MCS (dAIH + vehicle: 0.83 ± 0.01, dNx + vehicle: 0.73 ± 0.01ml/100g; p<0.001); KW6002 had no significant effect. dAIH enhanced contralateral (uninjured) diaphragm EMG activity, an effect attenuated by KW6002, during room air breathing and MCS (p<0.05). Although dAIH enhanced contralateral T2 EIC EMG activity during room air breathing, KW6002 had no effect. dAIH had no statistically significant effects on diaphragm or T2 EIC EMG activity ipsilateral to injury. Thus, two weeks post-C2HS: 1) dAIH enhances breathing capacity by effects on contralateral diaphragm and T2 EIC activity; and 2) dAIH-induced recovery is A2a dependent in diaphragm, but not T2 EIC. Daily AIH may be a useful in promoting functional recovery of breathing capacity after cervical spinal injury, but A2a receptor antagonists (eg. caffeine) may undermine its effectiveness shortly after
Halogenation of microcapsule walls
NASA Technical Reports Server (NTRS)
Davis, T. R.; Schaab, C. K.; Scott, J. C.
Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.
Keiliszewski, M.; Lamport, D. )
The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.
DiPALS: Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis - a randomised controlled trial.
McDermott, Christopher J; Bradburn, Mike J; Maguire, Chin; Cooper, Cindy L; Baird, Wendy O; Baxter, Susan K; Cohen, Judith; Cantrill, Hannah; Dixon, Simon; Ackroyd, Roger; Baudouin, Simon; Bentley, Andrew; Berrisford, Richard; Bianchi, Stephen; Bourke, Stephen C; Darlison, Roy; Ealing, John; Elliott, Mark; Fitzgerald, Patrick; Galloway, Simon; Hamdalla, Hisham; Hanemann, C Oliver; Hughes, Philip; Imam, Ibrahim; Karat, Dayalan; Leek, Roger; Maynard, Nick; Orrell, Richard W; Sarela, Abeezar; Stradling, John; Talbot, Kevin; Taylor, Lyn; Turner, Martin; Simonds, Anita K; Williams, Tim; Wedzicha, Wisia; Young, Carolyn; Shaw, Pamela J
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting in death, usually from respiratory failure, within 2-3 years of symptom onset. Non-invasive ventilation (NIV) is a treatment that when given to patients in respiratory failure leads to improved survival and quality of life. Diaphragm pacing (DP), using the NeuRx/4(®) diaphragm pacing system (DPS)™ (Synapse Biomedical, Oberlin, OH, USA), is a new technique that may offer additional or alternative benefits to patients with ALS who are in respiratory failure. OBJECTIVE The Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis (DiPALS) trial evaluated the effect of DP on survival over the study duration in patients with ALS with respiratory failure. DESIGN The DiPALS trial was a multicentre, parallel-group, open-label, randomised controlled trial incorporating health economic analyses and a qualitative longitudinal substudy. PARTICIPANTS Eligible participants had a diagnosis of ALS (ALS laboratory-supported probable, clinically probable or clinically definite according to the World Federation of Neurology revised El Escorial criteria), had been stabilised on riluzole for 30 days, were aged ≥ 18 years and were in respiratory failure. We planned to recruit 108 patients from seven UK-based specialist ALS or respiratory centres. Allocation was performed using 1 : 1 non-deterministic minimisation. INTERVENTIONS Participants were randomised to either standard care (NIV alone) or standard care (NIV) plus DP using the NeuRX/4 DPS. MAIN OUTCOME MEASURES The primary outcome was overall survival, defined as the time from randomisation to death from any cause. Secondary outcomes were patient quality of life [assessed by European Quality of Life-5 Dimensions, three levels (EQ-5D-3L), Short Form questionnaire-36 items and Sleep Apnoea Quality of Life Index questionnaire]; carer quality of life (EQ-5D-3L and Caregiver Burden Inventory); cost-utility analysis and health
Line-of-sight sealed silicon carbide diaphragms for harsh environment sensors
NASA Astrophysics Data System (ADS)
Jones, Debbie Gahaton
Silicon carbide (SiC) is currently being developed as a platform material for micro scale devices that operate in harsh environments. One vision of the future is an all-SiC sensor chip composed of crystalline SiC substrate, doped polycrystalline SiC structures, and sputtered amorphous SiC sealing layers. Such a chip would have minimal internal stresses over a wide thermal range. The chemical inertness, as well as the electrical and mechanical properties of SiC in harsh environments overcomes the limitations of traditional silicon-based platforms. The development of robust SiC devices requires fabrication techniques and a materials system that are compatible with the thermal budget and operational environment. This thesis describes a process for depositing wafer-level, SiC sealing layers for harsh environment sensors. An emerging method of diaphragm fabrication is a sealing technique that utilizes deposition of two thin films: a porous scaffold layer and a second sealing layer. This approach offers many advantages in comparison to traditional bulk etch methods such as improved wafer-level uniformity and reduction in die size. This work describes a novel approach for the fabrication of diaphragms by the utilization of an ion beam sputter deposition of amorphous SiC for line-of-sight sealing. The approach was developed to be compatible with harsh environment specifications and can be applied to applications such as vacuum encapsulation and pressure sensing. This thesis also presents the etching of SiC films and substrates, which is important for device feature definition. A high density plasma etch system was used to further explore the etching of SiC with SiO2 etch masks in HBr/Cl2 etch chemistries. An etch recipe was developed for the fabrication of a thin film SiC resonant strain gauge. In addition, the use of aluminum nitride (AlN) as an etch mask with SF6/O2 was investigated for the first time and demonstrated improved etch rates, selectivities and sidewall
Changes in diaphragm muscle collagen gene expression after acute unilateral denervation
NASA Technical Reports Server (NTRS)
Gosselin, L. E.; Sieck, G. C.; Aleff, R. A.; Martinez, D. A.; Vailas, A. C.
The purpose of the present study was to examine the effects of acute (3 days) unilateral diaphragm denervation (DNV) on 1) levels of alpha 1(I) and alpha 1(III) procollagen mRNA; 2) collagen concentration [hydroxyproline (HYP)]; 3) amount of the nonreducible collagen cross-link hydroxylysylpyridinoline (HP); and 4) the passive force-length relationship of the muscle. The levels of alpha 1(I) and alpha 1(III) procollagen mRNA, HYP concentration, and amount of HP were measured in muscle segments from the midcostal region of DNV and intact (INT) hemidiaphragms of adult male Fischer 344 rats (250-300 g). The in vitro passive force-length relationship of DNV and INT hemidiaphragm was determined by lengthening and shortening the diaphragm muscle segments from 85 to 115% of optimal length at a constant velocity (0.6 optimal length/s). Three days after DNV, the level of alpha 1(I) procollagen mRNA was increased over 15-fold in the DNV hemidiaphragm compared with INT (P < 0.05), whereas the level of alpha 1(III) procollagen mRNA was increased by approximately sixfold in the DNV hemidiaphragm compared with INT (P < 0.05). Collagen (HYP) concentration did not differ between groups, averaging 8.7 and 8.9 micrograms/mg dry wt for the DNV and INT hemidiaphragms, respectively. In addition, there was no difference in the amount of the mature nonreducible collagen cross-link HP between the DNV and INT hemidiaphragms (0.66 vs. 0.76 mole HP/mole collagen, respectively). The amount of passive force developed during lengthening did not differ between DNV and INT hemidiaphragms. These data indicate that acute DNV of the hemidiaphragm is associated with an increase in the mRNA level of the two principal fibrillar collagen phenotypes in skeletal muscle. However, despite extensive muscle remodeling, the passive force-length relationship of the DNV hemidiaphragm is unaffected compared with the INT muscle.
Analysis of the eigenvalue equation of the FEL amplifier with axisymmetric electron beam and diaphragm focusing line
Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N.
The paper presents analysis of the eigenvalue problem of the FEL amplifier with axisymmetric electron beam and diaphragm focusing line. An FEL model is discussed wherein diffraction effects, space charge fields and energy spread of electrons in the beam are taken into account. To take into account diffraction effects at the diaphragms we apply the rigorous impedance boundary conditions proposed by Veinstein. The rigorous solutions of the eigenvalue problem leave been found for the stepped and bounded parabolic electron beam profiles. Analytical expressions for eigenfunctions of active open waveguide and formulae of their expansion in eigenfunctions of passive open waveguide, are derived, too. Asymptotic behaviour of the obtained solutions is studied in details. The multilayer approximation method has been used to solve the eigenvalue problem for the beams with an arbitrary gradient profile of current density. This novel type of an FEL amplifier has perspective to be used for applications where high average and peak radiation power is required.
[Determination of aqueous potassium and sodium ions with liquid-phase diaphragm glow discharge-atomic emission spectrometry].
Liu, Yong-jun; Wang, Lei
The present paper described the determination of potassium and sodium ions with a liquid-phase diaphragm glow discharge emission spectroscopy (LDGD-AES) in aqueous solution. The discharge was formed in a pin hole on a dielectric diaphragm interposed between two submerged graphite electrodes. Effects of applied voltage and the addition of organic additive methanol on the determination were examined. It was found that increasing the applied voltage and adding of methanol can increase the detection sensitivity and decrease the detection limit. Limits of detection for K and Na were 0. 007 and 0. 001 mg x L(-1) under the applied voltage of 850 V and addition of 0.6%-0.8% methanol, respectively. It was demonstrated that the LDGD-AES is a promising technique in measurements of metal ions in aqueous solution, because no optical interferences from the electrodes and the background molecular bands from air were found. PMID:24369674
Design considerations to enhance the performances of thin circular piezoelectric energy harvester diaphragms in harsh liquid environments
NASA Astrophysics Data System (ADS)
Besse, N.; Pisano, A. P.; de Rooij, N. F.
Thin circular piezoelectric energy harvester diaphragms undergoing large deflection in a harsh liquid environment are investigated in this paper. A material set combining AlN as transducer, SiC as electronics, Mo as wiring and Si as holder is considered. A highly accurate analytical model, which presents less than 5% error compared to FEM simulations in COMSOL, is first developed to study thoroughly flat diaphragms. Consequently, etching the wafer and adding a corrugation are proposed to reduce both the stress concentration at the edge and the influence of residual stress on the device behavior, respectively. Both ideas are predicted to increase the power density compared to the standard flat case by at least a factor of 5 to 10.
Fluidized wall for protecting fusion chamber walls
Maniscalco, James A.; Meier, Wayne R.
Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.
Effects of Gestational and Postnatal Exposure to Chronic Intermittent Hypoxia on Diaphragm Muscle Contractile Function in the Rat
McDonald, Fiona B.; Dempsey, Eugene M.; O'Halloran, Ken D.
Alterations to the supply of oxygen during early life presents a profound stressor to physiological systems with aberrant remodeling that is often long-lasting. Chronic intermittent hypoxia (CIH) is a feature of apnea of prematurity, chronic lung disease, and sleep apnea. CIH affects respiratory control but there is a dearth of information concerning the effects of CIH on respiratory muscles, including the diaphragm—the major pump muscle of breathing. We investigated the effects of exposure to gestational CIH (gCIH) and postnatal CIH (pCIH) on diaphragm muscle function in male and female rats. CIH consisted of exposure in environmental chambers to 90 s of hypoxia reaching 5% O2 at nadir, once every 5 min, 8 h a day. Exposure to gCIH started within 24 h of identification of a copulation plug and continued until day 20 of gestation; animals were studied on postnatal day 22 or 42. For pCIH, pups were born in normoxia and within 24 h of delivery were exposed with dams to CIH for 3 weeks; animals were studied on postnatal day 22 or 42. Sham groups were exposed to normoxia in parallel. Following gas exposures, diaphragm muscle contractile, and endurance properties were examined ex vivo. Neither gCIH nor pCIH exposure had effects on diaphragm muscle force-generating capacity or endurance in either sex. Similarly, early life exposure to CIH did not affect muscle tolerance of severe hypoxic stress determined ex vivo. The findings contrast with our recent observation of upper airway dilator muscle weakness following exposure to pCIH. Thus, the present study suggests a relative resilience to hypoxic stress in diaphragm muscle. Co-ordinated activity of thoracic pump and upper airway dilator muscles is required for optimal control of upper airway caliber. A mismatch in the force-generating capacity of the complementary muscle groups could have adverse consequences for the control of airway patency and respiratory homeostasis. PMID:27462274
Diaphragm and lubricant gel for prevention of HIV acquisition in southern African women: a randomised controlled trial
Padian, Nancy S; van der Straten, Ariane; Ramjee, Gita; Chipato, Tsungai; de Bruyn, Guy; Blanchard, Kelly; Shiboski, Stephen; Montgomery, Elizabeth T; Fancher, Heidi; Cheng, Helen; Rosenblum, Michael; van der Laan, Mark; Jewell, Nicholas; McIntyre, James
Summary Background Female-controlled methods of HIV prevention are urgently needed. We assessed the effect of provision of latex diaphragm, lubricant gel, and condoms (intervention), compared with condoms alone (control) on HIV seroincidence in women in South Africa and Zimbabwe. Methods We did an open-label, randomised controlled trial in HIV-negative, sexually active women recruited from clinics and community-based organisations, who were followed up quarterly for 12–24 months (median 21 months). All participants received an HIV prevention package consisting of pre-test and post-test counselling about HIV and sexually transmitted infections, testing, treatment of curable sexually transmitted infections, and intensive risk-reduction counselling. The primary outcome was incident HIV infection. This study is registered with ClinicalTrials.gov, number NCT00121459. Findings Overall HIV incidence was 4.0% per 100 woman-years: 4.1% in the intervention group (n=2472) and 3.9% in the control group (n=2476), corresponding to a relative hazard of 1.05 (95% CI 0.84–1.32, intention-to-treat analysis). The proportion of women using condoms was significantly lower in the intervention than in the control group (54% vs 85% of visits, p<0.0001). The proportions of participants who reported adverse events (60% [1523] vs 61% [1529]) and serious adverse events (5% [130] vs 4% [101]) were similar between the two groups. Interpretation We observed no added protective benefit against HIV infection when the diaphragm and lubricant gel were provided in addition to condoms and a comprehensive HIV prevention package. Our observation that lower condom use in women provided with diaphragms did not result in increased infection merits further research. Although the intervention seemed safe, our findings do not support addition of the diaphragm to current HIV prevention strategies. PMID:17631387
Olive, Keith A.; Peloso, Marco; Uzan, Jean-Philippe
We consider the signatures of a domain wall produced in the spontaneous symmetry breaking involving a dilatonlike scalar field coupled to electromagnetism. Domains on either side of the wall exhibit slight differences in their respective values of the fine-structure constant, {alpha}. If such a wall is present within our Hubble volume, absorption spectra at large redshifts may or may not provide a variation in {alpha} relative to the terrestrial value, depending on our relative position with respect to the wall. This wall could resolve the contradiction between claims of a variation of {alpha} based on Keck/Hires data and of the constancy of {alpha} based on Very Large Telescope data. We derive the properties of the wall and the parameters of the underlying microscopic model required to reproduce the possible spatial variation of {alpha}. We discuss the constraints on the existence of the low-energy domain wall and describe its observational implications concerning the variation of the fundamental constants.
Emphysema quantification from CT scans using novel application of diaphragm curvature estimation: comparison with standard quantification methods and pulmonary function data
NASA Astrophysics Data System (ADS)
Keller, Brad M.; Reeves, Anthony P.; Yankelevitz, David F.; Henschke, Claudia I.; Barr, R. Graham
Emphysema is a disease of the lungs that destroys the alveolar air sacs and induces long-term respiratory dysfunction. CT scans allow for the imaging of the anatomical basis of emphysema and quantification of the underlying disease state. Several measures have been introduced for the quantification emphysema directly from CT data; most,however, are based on the analysis of density information provided by the CT scans, which vary by scanner and can be hard to standardize across sites and time. Given that one of the anatomical variations associated with the progression of emphysema is the flatting of the diaphragm due to the loss of elasticity in the lung parenchyma, curvature analysis of the diaphragm would provide information about emphysema from CT. Therefore, we propose a new, non-density based measure of the curvature of the diaphragm that would allow for further quantification methods in a robust manner. To evaluate the new method, 24 whole-lung scans were analyzed using the ratios of the lung height and diaphragm width to diaphragm height as curvature estimates as well as using the emphysema index as comparison. Pearson correlation coefficients showed a strong trend of several of the proposed diaphragm curvature measures to have higher correlations, of up to r=0.57, with DLCO% and VA than did the emphysema index. Furthermore, we found emphysema index to have only a 0.27 correlation to the proposed measures, indicating that the proposed measures evaluate different aspects of the disease.
Amorphous silicon carbonitride diaphragm for environmental-cell transmission electron microscope fabricated by low-energy ion beam induced chemical vapor deposition
NASA Astrophysics Data System (ADS)
Matsutani, Takaomi; Yamasaki, Kayo; Imaeda, Norihiro; Kawasaki, Tadahiro
An amorphous silicon carbonitride (a-SiCN) diaphragm for an environmental-cell transmission electron microscope (E-TEM) was fabricated by low-energy ion beam induced chemical vapor deposition (LEIBICVD) with hexamethyldisilazane (HMDSN). The films were prepared by using gaseous HMDSN and N2+ ions with energies ranging from 300 to 600 eV. The diaphragms were applied to Si (1 0 0) and a Cu grid with 100-μm-diameter holes. With increasing ion energy, these diaphragms became perfectly smooth surfaces (RMS = 0.43 nm at 600 eV), as confirmed by atomic force microscopy and TEM. The diaphragms were amorphous and transparent to 200 kV electrons, and no charge-up was observed. Fourier transform infrared spectra and X-ray photoelectron spectra revealed that the elimination of organic compounds and formation of Si-N and C-N bonds can be promoted in diaphragms by increasing the ion impact energy. The resistance to electron beams and reaction gases in the E-cell was improved when the diaphragm was formed with high ion energy.
Mechanical characterization of the mouse diaphragm with optical coherence elastography reveals fibrosis-related change of direction-dependent muscle tissue stiffness
NASA Astrophysics Data System (ADS)
Wang, Shang; Loehr, James A.; Larina, Irina V.; Rodney, George G.; Larin, Kirill V.
The diaphragm, composed of skeletal muscle, plays an important role in respiration through its dynamic contraction. Genetic and molecular studies of the biomechanics of mouse diaphragm can provide great insights into an improved understanding and potential treatment of the disorders that lead to diaphragm dysfunction (i.e. muscular dystrophy). However, due to the small tissue size, mechanical assessment of mouse diaphragm tissue under its proper physiological conditions has been challenging. Here, we present the application of noncontact optical coherence elastography (OCE) for quantitative elastic characterization of ex vivo mouse diaphragm. Phase-sensitive optical coherence tomography was combined with a focused air-puff system to capture and measure the elastic wave propagation from tissue surface. Experiments were performed on wildtype and dystrophic mouse diaphragm tissues containing different levels of fibrosis. The OCE measurements of elastic wave propagation were conducted along both the longitudinal and transverse axis of the muscle fibers. Cross-correlation of the temporal displacement profiles from different spatial locations was utilized to obtain the propagation time delay, which was used to calculate the wave group velocity and to further quantify the tissue Young's modulus. Prior to and after OCE assessment, peak tetanic force was measured to monitor viability of the tissue during the elasticity measurements. Our experimental results indicate a positive correlation between fibrosis level and tissue stiffness, suggesting this elastic-wave-based OCE method could be a useful tool to monitor mechanical properties of skeletal muscle under physiological and pathological conditions.
Silicon-based guided-wave optical flow sensor using a diaphragm with a small opening as an orifice
NASA Astrophysics Data System (ADS)
Ohkawa, Masashi; Sato, Takashi
Our proposed silicon-based guided-wave optical flow sensor consists of a diaphragm with a small opening used as an orifice and a waveguide across the diaphragm. The sensor operates based on Bernoulli's theorem and the elasto-optic effect. A sensor, which had a 10×10-mm2, 50-μm-thick diaphragm with a 0.34×0.34-mm2 opening, was fabricated to demonstrate and confirm the sensor operation. Measured output power as a function of flow rate using oxygen gas agreed quite well with the theoretical prediction although slight deviation was seen in the high flow rate region. Moreover, according to Bernoulli's theorem, sensitivity is strongly dependent on sectional area of opening. So, three sensors with different opening areas, such as 0.28×0.28, 0.34×0.34, and 0.55×0.55 mm2, were fabricated to examine such a dependence, which would be helpful to design the sensor. The measured sensitivity was found to be almost proportional to area of the opening, similar to the theoretical prediction.
Enhancing the sensitivity of a micro-diaphragm resonating sensor by effectively positioning the mass on the membrane
Kim, Jinsik; Kim, Hye Jin; Cho, EunAe; Shin, Hyun-Joon; Park, Jung Ho; Hwang, Kyo Seon
The detection of biomarkers in the liquid phase using mechanical sensors is difficult because of noise caused by the liquid. To reduce and verify the side effects of liquid loading, we performed calculations and experiments to determine the shift in resonant frequency according to the loading conditions. A 2-μm-thick piezoelectric rectangular micro-diaphragm with a 500 × 500 μm membrane was used. These dimensions were determined such that there would be an analogous resonant frequency shift ratio in both (1, 1) and (2, 2) modes. By calculating and measuring the resonant frequency, we verified that the resonant frequency of the sensor would change only through contact with the liquid, even the resonant frequency change by only liquid much higher than the changes caused by the nanoparticles. The real signal constituted only 0.017% of the initial resonant frequency. To enhance the sensitivity by reducing the unexpected surface stress in the liquid, the liquid was dropped onto the surface of the micro-diaphragm. This resulted in an improvement of more than 10 times the sensitivity in both modes. In addition, by controlling the position in the micro-diaphragm resonating sensor, more sensitive positions with large displacements were determined according to each mode. PMID:26594022
The effect of respiratory muscle training with CO2 breathing on cellular adaptation of mdx mouse diaphragm
Matécki, Stefan; Rivier, François; Hugon, Gerald; Koechlin, Christelle; Michel, Alain; Préfaut, Christian; Mornet, Dominique; Ramonatxo, Michèle
The aim of our study was to investigate the cellular mechanisms induced by hypercapnic stimulation of ventilation, during 6 weeks/30 min per day, in 10 mdx and 8 C57BL10 mice (10G0.2 months old). Ten mdx and eight C57BL10 mice served as control group. This respiratory training increases in vitro maximal tetanic tension of the diaphragm only in mdx mice. Western blot analysis of diaphragm showed: (1) an over-expression of a-dystrobrevin in mdx and C57BL10 training group compared to control group (8100G710 versus 6100G520 and 2800G400 versus 2200G250 arbitrary units); (2) a decrease in utrophin expression only in mdx training group compared to control group (2100G320 versus 3100G125 arbitrary units). Daily respiratory muscle training in mdx mice, induces a beneficial effect on diaphragm strength, with an over-expression of a-dystrobrevin. Further studies are needed to determine if, in absence of dystrophin, the over-expression of a-dystrobrevin could be interpreted as a possible pathway to improve function of dystrophic muscle. PMID:15907290
A Computational Investigation for Determining the Natural Frequencies and Damping Effects of Diaphragm-Implemented Spacecraft Propellant Tanks
NASA Technical Reports Server (NTRS)
Lenahen, Brian; Bernier, Adrien; Gangadharan, Sathya; Sudermann, James; Marsell, Brandon
Spin-stabilization maneuvers are typically performed by spacecraft entering low-earth orbit to maintain attitude stability. These maneuvers induce periodic fluid movement inside the spacecraft's propellant tank known as fuel slosh, which is responsible for creating forces and moments on the sidewalls of the propellant tank. These forces and moments adversely affect spin-stabilization and risk jeopardizing the mission of the spacecraft. Therefore, propellant tanks are designed with propellant management devices (PMD's) such as barnes or diaphragms which work to counteract the forces and moments associated with fuel slosh. However, despite the presence of PMD's, the threat of spin-stabilization interference still exists should the propellant tank be excited at its natural frequency. When the fluid is excited at its natural frequency, the forces and moments acting on the propellant tank are amplified and may result in destabilizing the spacecraft. Thus, a computational analysis is conducted concerning diaphragm-implemented propellant tanks excited at their natural frequencies. Using multi-disciplinary computational fluid dynamics (CFD) software, computational models are developed to reflect potential scenarios that spacecraft propellant tanks could experience. By simulating the propellant tank under a wide array of parameters and variables including fill-level, gravity and diaphragm material and shape, a better understanding is gained as to how these parameters individually and collectively affect liquid propellant tanks and ultimately, spacecraft attitude dynamics.
Improved load-deflection method for the extraction of elastomechanical properties of circularly shaped thin-film diaphragms
NASA Astrophysics Data System (ADS)
Schalko, Johannes; Beigelbeck, Roman; Stifter, Michael; Schneider, Michael; Bittner, Achim; Schmid, Ulrich
The load-deflection (LD) method is a common and convenient procedure to extract the Young's modulus and the internal tensile stress of thin-film diaphragms from measurements of the maximum transverse deflection to a uniformly distributed load. This technique allows simultaneous determination of both parameters by fitting a theoretical to an experimental LD characteristic. Consequently, a proper knowledge of such a theoretical relationship is of utmost importance to obtain accurate values. We deduced a novel LD formula covering all relevant elastomechanical bending and stretching effects. It enables an easy but still accurate extraction of the Young's modulus and the internal tensile stress from LD measurements on circularly-shaped diaphragms. This LD relationship was derived from an adaptation of Timoshenko's membrane bending theory, where the in-plane and the out-of-plane deflections were approximated by a series expansion and a polynomial, respectively. Utilizing the minimum total potential energy principle yielded an infinite-dimensional system of equations which was solved analytically resulting in a compact closed-form solution. The flexibility of our approach is demonstrated by extracting the Young's modulus and the internal tensile stress of three disparate diaphragm materials made of either sputtered AlN, PECVD SixNy, or microfiltered carbon nanotubes (bucky paper).
Acceptability and Use of the Diaphragm and Replens® Lubricant Gel for HIV Prevention in Southern Africa
Cheng, Helen; van der Straten, Ariane; Chidanyika, Agnes C.; Lince, Naomi; Blanchard, Kelly; Ramjee, Gita; Nkala, Busisiwe; Padian, Nancy S.
The acceptability and use of the diaphragm and lubricant gel were assessed as part of a large randomized controlled trial to determine the effectiveness of the methods in women's HIV acquisition. 2,452 intervention-arm women were enrolled at five Southern African clinics and followed quarterly for 12–24 months. Acceptability and use data were collected by face-to-face interviews at Month 3 and Exit. Participants were "very comfortable" with the physical mechanics of diaphragm use throughout the trial, and approval of the gel consistency, quantity and the applicator was high. At Exit, consistent disclosure of use (AOR 1.97, 95% CI: 1.10–3.55); an overall high diaphragm rating (AOR 1.84, 95% CI: 1.45–2.34) and perception of partner approval (AOR 1.75, 95% CI: 1.35–2.26) were the most significant acceptability factors independently associated with consistent use. Despite being female-initiated, disclosure of use to male partners and his perceived approval of the products were factors significantly associated with their consistent use. PMID:19757018
Open Transthoracic Plication of the Diaphragm for Unilateral Diaphragmatic Eventration in Infants and Children
Alshorbagy, Ashraf; Mubarak, Yasser
Background To evaluate our experience of early surgical plication for diaphragmatic eventration (DE) in infancy and childhood. Methods This study evaluated infants and children with symptomatic DE who underwent plication through an open transthoracic approach in our childhood development department between January 2005 and December 2012. Surgical plication was performed in several rows using polypropylene U-stitches with Teflon pledgets. Results The study included 12 infants and children (7 boys and 5 girls) with symptomatic DE (9 congenital and 3 acquired). Reported symptoms included respiratory distress (91.7%), wheezing (75%), cough (66.7%), and recurrent pneumonia (50%). Preoperative mechanical ventilatory support was required in 41.7% of the patients. The mean length of hospital stay was 6.3±2.5 days. The mean follow-up period was 24.3±14.5 months. Preoperative symptoms were immediately relieved after surgery in 83.3% of patients and persisted in 16.7% of patients one year after surgery. All patients survived to the end of the two-year follow-up and none had recurrence of DE. Conclusion Early diagnosis and surgical plication of the diaphragm for symptomatic congenital or acquired diaphragmatic eventration offers a good clinical outcome with no recurrence. PMID:26509123
Effects of boldine on mouse diaphragm and sarcoplasmic reticulum vesicles isolated from skeletal muscle.
Kang, J J; Cheng, Y W
The effects of boldine [(S)-2,9-dihydroxy-1,10-dimethoxyaporphine], a major alkaloid in the leaves and bark of boldo (Peumus boldus Mol.), on skeletal muscle were studied using mouse diaphragm and isolated sarcoplasmic reticulum membrane vesicles. Boldine, at 10-200 microM, has little effect on the muscle-evoked twitches; however, the ryanodine-induced contracture was potentiated dose-dependently. At higher concentrations of 300 microM, boldine by itself induced muscle contracture of two phases, which were caused by the influx of extracellular Ca2+ and induction of Ca2+ release from the internal Ca2+ storage site, the sarcoplasmic reticulum, respectively. When tested with isolated sarcoplasmic reticulum membrane vesicles, boldine dose-dependently induced Ca2+ release from actively loaded sarcoplasmic reticulum vesicles isolated from skeletal muscle of rabbit or rat which was inhibited by ruthenium red, suggesting that the release was through the Ca2+ release channel, also known as the ryanodine receptor. Boldine also dose-dependently increased apparent [3H]-ryanodine binding with the EC50 value of 50 microM. In conclusion, we have shown that boldine could sensitize the ryanodine receptor and induce Ca2+ release from the internal Ca2+ storage site of skeletal muscle. PMID:9491763
Optimal Design by Using Various Solutions for Vibration of Laminated Shallow Shells on Shear Diaphragms
NASA Astrophysics Data System (ADS)
Narita, Y.; Nitta, T.
Free vibration and corresponding optimal design problems are solved for laminated composite shallow shells of rectangular planform. The shells have symmetric laminated construction and are supported by shear diaphragms along the edges. The first-order transverse shear deformation is assumed in the Donnell type shell theory to account for the thickness shear effect, and an analytical solution is presented which is exact for cross-ply laminates and is approximate for angle-ply laminates. A simplified formula is also derived by neglecting inplane inertia terms. Analytical solutions with/without the inplane inertia terms from the classical thin shell theory are also shown. In numerical examples, natural frequencies are presented for various types of shell curvature, e.g., circular cylindrical, spherical and hyperbolic paraboloidal shells. Fibre orientation angles, which cause the maximized fundamental frequencies of the alternating angle-ply shells, are determined, and effects of using the four different vibration solutions are discussed on the optimal frequencies and fibre orientation angles. Questions of how the different solutions quantitatively affect the optimal design results and which solution is recommended in the present type of optimization problems are clarified in the conclusions.
Compressing Spin-Polarized 3He With a Modified Diaphragm Pump
Gentile, T. R.; Rich, D. R.; Thompson, A. K.; Snow, W. M.; Jones, G. L.
Nuclear spin-polarized 3He gas at pressures on the order of 100 kPa (1 bar) are required for several applications, such as neutron spin filters and magnetic resonance imaging. The metastability-exchange optical pumping (MEOP) method for polarizing 3He gas can rapidly produce highly polarized gas, but the best results are obtained at much lower pressure (~0.1 kPa). We describe a compact compression apparatus for polarized gas that is based on a modified commercial diaphragm pump. The gas is polarized by MEOP at a typical pressure of 0.25 kPa (2.5 mbar), and compressed into a storage cell at a typical pressure of 100 kPa. In the storage cell, we have obtained 20 % to 35 % 3He polarization using pure 3He gas and 35 % to 50 % 3He polarization using 3He-4He mixtures. By maintaining the storage cell at liquid nitrogen temperature during compression, the density has been increased by a factor of four. PMID:27500044
Effect of theophylline on membrane potential and contractile force in hamster diaphragm muscle in vitro.
Esau, S
Theophylline enhances the force of diaphragmatic contraction and delays fatigue. The mechanism is not known, but recent evidence suggests it may act at the cell membrane. To test this hypothesis, we studied the effect of theophylline on resting membrane potential and tension in hamster diaphragm cells. Muscle strips were obtained from five adult hamsters and placed in Krebs solution, aerated with 95% O2, 5% CO2. Resting membrane potential was measured using 3-M KCl-filled glass microelectrodes; 15-22 fibers in each strip were sampled. Force frequency curves (twitch to 100 Hz) were obtained. The muscle bath was then changed to one containing 100 mg/liter (0.55) theophylline. Resting membrane potential was -76 +/- 3 mV (mean +/- S.D.) in Krebs solution and increased to -85 +/- 3 mV (P less than 0.01) with added theophylline. Tension increased from 5% (at 100 Hz) to 20% (at 10 Hz) with theophylline. Hyperpolarization indicates an increase in intracellular to extracellular potassium concentration. Net potassium outflow occurs with each contraction, causing the cell membrane to become depolarized with repeated contractions, ultimately leading to fatigue. The hyperpolarization of the skeletal muscle cell membrane observed with theophylline may play an important role in prolonging time to fatigue. PMID:3944272
Analysis of muscle fiber clustering in the diaphragm muscle of sarcopenic mice
Greising, Sarah M.; Medina-Martínez, Juan S.; Vasdev, Amrit K.; Sieck, Gary C.; Mantilla, Carlos B.
Introduction Sarcopenia likely comprises muscle fiber denervation and re-innervation, resulting in clustering of muscle fibers of the same type (classified by myosin heavy chain isoform composition). Development of methodology to quantitatively evaluate clustering of muscle fibers according to fiber type is necessary. Methods Fiber type specific immunofluorescence histology was used to quantify fiber clustering in murine diaphragm muscle (n=15) at 6 and 24 months of age. Results With age, fiber type clustering is evidenced by fiber type specific changes in distances between fibers, specifically a 14% decrease to the closest fiber for type I and 24% increase for type IIx and/or IIb fibers (P<0.001). Additionally, a 34% increase to the 3 closest type IIx and/or IIb fibers was found (P<0.001). Discussion This novel method of analyzing fiber type clustering may be useful in examining pathophysiological conditions of motor unit loss in neuromuscular disorders, myopathies, dystrophies, injuries, or amyotrophic lateral sclerosis. PMID:25808550
Meier, W R
The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.
Pogorelko, Gennady; Lionetti, Vincenzo; Bellincampi, Daniela; Zabotina, Olga
The plant cell wall, a dynamic network of polysaccharides and glycoproteins of significant compositional and structural complexity, functions in plant growth, development and stress responses. In recent years, the existence of plant cell wall integrity (CWI) maintenance mechanisms has been demonstrated, but little is known about the signaling pathways involved, or their components. Examination of key mutants has shed light on the relationships between cell wall remodeling and plant cell responses, indicating a central role for the regulatory network that monitors and controls cell wall performance and integrity. In this review, we present a short overview of cell wall composition and discuss post-synthetic cell wall modification as a valuable approach for studying CWI perception and signaling pathways. PMID:23857352
Soil bentonite wall protects foundation from thrust faulting: analyses and experiment
NASA Astrophysics Data System (ADS)
Fadaee, Meysam; Anastasopoulos, I.; Gazetas, G.; Jafari, M. K.; Kamalian, M.
When seismic thrust faults emerge on the ground surface, they are particularly damaging to buildings, bridges and lifelines that lie on the rupture path. To protect a structure founded on a rigid raft, a thick diaphragm-type soil bentonite wall (SBW) is installed in front of and near the foundation, at sufficient depth to intercept the propagating fault rupture. Extensive numerical analyses, verified against reduced-scale (1 g) split box physical model tests, reveal that such a wall, thanks to its high deformability and low shear resistance, "absorbs" the compressive thrust of the fault and forces the rupture to deviate upwards along its length. As a consequence, the foundation is left essentially intact. The effectiveness of SBW is demonstrated to depend on the exact location of the emerging fault and the magnitude of the fault offset. When the latter is large, the unprotected foundation experiences intolerable rigid-body rotation even if the foundation structural distress is not substantial.
Vitamin D3 intake modulates diaphragm but not peripheral muscle force in young mice.
Ray, Andrew D; Personius, Kirkwood E; Williamson, David L; Dungan, Cory M; Dhillon, Samjot S; Hershberger, Pamela A
Recent data support an important role for vitamin D in respiratory health. We tested the hypothesis that dietary vitamin D3 (VD3) intake modulates diaphragm (DIA) strength. Four-week-old female A/J mice (n = 10/group) were randomized to receive diets containing 100 IU VD3/kg (low), 1,000 IU VD3/kg (reference), or 10,000 IU VD3/kg (pharmacologic). After 6 wk of dietary intervention, plasma 25-hydroxyvitamin D3 (25D3) levels, DIA and extensor digitorum longus (EDL) in vitro contractile properties, and fiber cross-sectional area (CSA) were measured. Myosin heavy chain (MHC) composition and Akt/Foxo3A growth signaling were studied in the DIA and tibialis anterior. Mice fed the low, reference, and pharmacologic diets had average 25D3 levels of 7, 21, and 59 ng/ml, respectively. Maximal DIA force, twitch force, and fiber CSA were reduced 26%, 28%, and 10% (P < 0.01), respectively, in mice receiving the low-VD3 diet compared with the reference and pharmacologic diets. EDL force parameters were unaltered by diet. Effects of VD3 intake on DIA force were not observed in mice that began dietary intervention at 12 wk of age. VD3 intake did not alter the MHC composition of the DIA, indicating that decreases in force and CSA in young mice were not due to a switch in fiber type. Paradoxically, low VD3 intake was associated with activation of anabolic signaling in muscle (hyperphosphorylation of Akt and Foxo3A and decreased expression of autophagy marker LC3). These studies identify a potential role of dietary VD3 in regulating DIA development and insulin sensitivity. PMID:26968027
Superoxide scavengers augment contractile but not energetic responses to hypoxia in rat diaphragm.
Wright, V P; Klawitter, P F; Iscru, D F; Merola, A J; Clanton, T L
Acute exposure to severe hypoxia depresses contractile function and induces adaptations in skeletal muscle that are only partially understood. Previous studies have demonstrated that antioxidants (AOXs) given during hypoxia partially protect contractile function, but this has not been a universal finding. This study confirms that specific AOXs, known to act primarily as superoxide scavengers, protect contractile function in severe hypoxia. Furthermore, the hypothesis is tested that the mechanism of protection involves preservation of high-energy phosphates (ATP, creatine phosphate) and reductions of P(i). Rat diaphragm muscle strips were treated with AOXs and subjected to 30 min of hypoxia. Contractile function was examined by using twitch and tetanic stimulations and the degree of elevation in passive force occurring during hypoxia (contracture). High-energy phosphates were measured at the end of 30-min hypoxia exposure. Treatment with the superoxide scavengers 4,5-dihydroxy-1,3-benzenedisulfonic acid (Tiron, 10 mM) or Mn(III)tetrakis(1-methyl-4-pyridyl) porphyrin pentachloride (50 microM) suppressed contracture during hypoxia and protected maximum tetanic force. N-acetylcysteine (10 or 18 mM) had no influence on tetanic force production. Contracture during hypoxia without AOXs was also shown to be dependent on the extracellular Ca(2+) concentration. Although hypoxia resulted in only small reductions in ATP concentration, creatine phosphate concentration was decreased to approximately 10% of control. There were no consistent influences of the AOX treatments on high-energy phosphates during hypoxia. The results demonstrate that superoxide scavengers can protect contractile function and reduce contracture in hypoxia through a mechanism that does not involve preservation of high-energy phosphates. PMID:15640388
Wall Finishes; Carpentry: 901895.
ERIC Educational Resources Information Center
Dade County Public Schools, Miami, FL.
The course outline is designed to provide instruction in selecting, preparing, and installing wall finishing materials. Prerequisites for the course include mastery of building construction plans, foundations and walls, and basic mathematics. Intended for use in grades 11 and 12, the course contains five blocks of study totaling 135 hours of…
J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka
Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.
NASA Technical Reports Server (NTRS)
This image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial 'clodding' or cementation of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) across and makes up half of the projected 'Stucco Walls' image.
ERIC Educational Resources Information Center
Jackson, Julie; Narvaez, Rose
It is common to see word walls displaying the vocabulary that students have learned in class. Word walls serve as visual scaffolds and are a classroom strategy used to reinforce reading and language arts instruction. Research shows a strong relationship between student word knowledge and academic achievement (Stahl and Fairbanks 1986). As a…
Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver
We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.
Lung and chest wall mechanics in microgravity.
Edyvean, J; Estenne, M; Paiva, M; Engel, L A
We studied the effect of 15-20 s of weightlessness on lung, chest wall, and abdominal mechanics in five normal subjects inside an aircraft flying repeated parabolic trajectories. We measured flow at the mouth, thoracoabdominal and compartmental volume changes, and gastric pressure (Pga). In two subjects, esophageal pressures were measured as well, allowing for estimates of transdiaphragmatic pressure (Pdi). In all subjects functional residual capacity at 0 Gz decreased by 244 +/- 31 ml as a result of the inward displacement of the abdomen. End-expiratory Pga decreased from 6.8 +/- 0.8 cmH2O at 1 Gz to 2.5 +/- 0.3 cmH2O at Gz (P less than 0.005). Abdominal contribution to tidal volume increased from 0.33 +/- 0.05 to 0.51 +/- 0.04 at 0 Gz (P less than 0.001) but delta Pga showed no consistent change. Hence abdominal compliance increased from 43 +/- 9 to 70 +/- 10 ml/cmH2O (P less than 0.05). There was no consistent effect of Gz on tidal swings of Pdi, on pulmonary resistance and dynamic compliance, or on any of the timing parameters determining the temporal pattern of breathing. The results indicate that at 0 G respiratory mechanics are intermediate between those in the upright and supine postures at 1 G. In addition, analysis of end-expiratory pressures suggests that during weightlessness intra-abdominal pressure is zero, the diaphragm is passively tensed, and a residual small pleural pressure gradient may be present. PMID:1761497
Peptide-based inhibition of NF-κB rescues diaphragm muscle contractile dysfunction in a murine model of Duchenne muscular dystrophy.
Peterson, Jennifer M; Kline, William; Canan, Benjamin D; Ricca, Daniel J; Kaspar, Brian; Delfín, Dawn A; DiRienzo, Kelly; Clemens, Paula R; Robbins, Paul D; Baldwin, Albert S; Flood, Pat; Kaumaya, Pravin; Freitas, Michael; Kornegay, Joe N; Mendell, Jerry R; Rafael-Fortney, Jill A; Guttridge, Denis C; Janssen, Paul M L
Deterioration of diaphragm function is one of the prominent factors that contributes to the susceptibility of serious respiratory infections and development of respiratory failure in patients with Duchenne Muscular Dystrophy (DMD). The NF-κB signaling pathway has been implicated as a contributing factor of dystrophic pathology, making it a potential therapeutic target. Previously, we demonstrated that pharmacological inhibition of NF-κB via a small NEMO Binding Domain (NBD) peptide was beneficial for reducing pathological features of mdx mice. Now, we stringently test the effectiveness and clinical potential of NBD by treating mdx mice with various formulations of NBD and use diaphragm function as our primary outcome criteria. We found that administering DMSO-soluble NBD rescued 78% of the contractile deficit between mdx and wild-type (WT) diaphragm. Interestingly, synthesis of a GLP NBD peptide as an acetate salt permitted its solubility in water, but as a negative consequence, also greatly attenuated functional efficacy. However, replacing the acetic acid counterion of the NBD peptide with trifluoroacetic acid retained the peptide's water solubility and significantly restored mdx diaphragm contractile function and improved histopathological indices of disease in both diaphragm and limb muscle. Together, these results support the feasibility of using a mass-produced, water-soluble NBD peptide for clinical use. PMID:21267511
Thoracic wall defects: surgical management of 205 consecutive patients
Pairolero, P.C.; Arnold, P.G.
In this article, we review our experience during the past 9 years with 205 consecutive thoracic wall reconstructions. The 100 female and 105 male patients ranged in age from 12 to 85 years (mean, 53.4 years). One hundred fourteen patients had thoracic wall tumors, 56 had radiation necrosis, 56 had infected median sternotomy wounds, and 8 had costochondritis. Twenty-nine of these patients had combinations of the aforementioned conditions. One hundred seventy-eight patients underwent skeletal resection. A mean of 5.4 ribs were resected in 142 patients. Total or partial sternectomies were performed in 60. Skeletal defects were closed with prosthetic material in 66 patients and with autogenous ribs in 12. One hundred sixty-eight patients underwent 244 muscle flap procedures: 149 pectoralis major, 56 latissimus dorsi, 14 rectus abdominis, 13 serratus anterior, 8 external oblique, 2 trapezius, and 2 advancement of diaphragm. The omentum was transposed in 20 patients. The mean number of operations per patient was 1.9 (range, 1 to 8). The mean duration of hospitalization was 16.5 days. One perioperative death occurred (at 29 days). Four patients required tracheostomy. During a mean follow-up of 32.4 months, there were 49 late deaths, predominantly due to malignant disease. All 204 patients who were alive 30 days after operation had excellent surgical results at last follow-up examination or at the time of death due to causes unrelated to the reconstructive procedure.
COMMUNICATION: The effects of elevated body temperature on the complexity of the diaphragm EMG signals during maturation
NASA Astrophysics Data System (ADS)
Akkurt, David; Akay, Yasemin M.; Akay, Metin
In this paper, we examine the effect of elevated body temperature on the complexity of the diaphragm electromyography (EMGdia), the output of the respiratory neural network--using the approximate entropy method. The diaphragm EMG, EEG, EOG as well as other physiological signals (tracheal pressure, blood pressure and respiratory volume) in chronically instrumented rats were recorded at two postnatal ages: 25-35 days age (juvenile, n = 5) and 36-44 days age (early adult, n = 6) groups during control (36-37 °C), mild elevated body temperature (38 °C) and severe elevated body temperature (39-40 °C). Three to five trials of the recordings were performed at normal body temperature before raising the animal's core temperature by 1-4 °C with an electric heating pad. At the elevated temperature, another 3-5 trials were performed. Finally, the animal was cooled to the original temperature, and trials were again repeated. Complexity values of the diaphragm EMG signal were estimated and evaluated using the approximate entropy method (ApEn) over the ten consecutive breaths. Our results suggested that the mean approximate entropy values for the juvenile age group were 1.01 ± 0.01 (standard error) during control, 0.91 ± 0.02 during mild elevated body temperature and 0.81 ± 0.02 during severe elevated body temperature. For the early adult age group, these values were 0.94 ± 0.01 during control, 0.93 ± 0.01 during mild elevated body temperature and 0.92 ± 0.01 during severe elevated body temperature. Our results show that the complexity values and the durations of the diaphragm EMG (EMGdia) were significantly decreased when the elevated body temperature was shifted from control or mild to severe body temperature (p < 0.05) for the juvenile age group. However, for the early adult age group, an increase in body temperature slightly reduced the complexity measures and the duration of the EMGdia. But, these changes were not statistically significant. These results furthermore
5. Detail of bin wall, showing the thinner exterior wall ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
5. Detail of bin wall, showing the thinner exterior wall next to the inner wall with its alternating courses of channel tile and hollow tile. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
22. SIDE WALL CONSTRUCTION, NORTH TRAINING WALL, LOOKING WEST FROM THE SAME POINT AS VIEW NO. 21. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA
NASA Astrophysics Data System (ADS)
Quinn, Daniel; Moored, Keith; Dewey, Peter; Lauder, George; Smits, Alexander
The aerodynamic loads on rectangular panels undergoing heave and pitch oscillations near a solid wall were measured using a 6-axis ATI sensor. Over a range of Strouhal numbers, reduced frequencies and flexibilities, swimming near the wall was found to increase thrust and therefore the self-propelled swimming speed. Experimental particle image velocimetry revealed an asymmetric wake structure with a momentum jet angled away from the wall. Both the thrust amplification and the asymmetric wake structure were verified and investigated further using an in-house inviscid panel method code. Supported by ONR MURI Grant N00014-08-1-0642.
Diaphragm Repair with a Novel Cross-Linked Collagen Biomaterial in a Growing Rabbit Model
Mayer, Steffi; Decaluwe, Herbert; Ruol, Michele; Manodoro, Stefano; Kramer, Manuel; Till, Holger; Deprest, Jan
Background Neonates with congenital diaphragmatic hernia and large defects often require patch closure. Acellular collagen matrices (ACM) have been suggested as an alternative to synthetic durable patches as they are remodeled by the host or could also be used for tissue engineering purposes. Materials and Methods 2.0x1.0 cm diaphragmatic defects were created in 6-weeks old New-Zealand white rabbits. We compared reconstruction with a purpose-designed cross-linked ACM (Matricel) to 4-layer non-cross-linked small intestinal submucosa (SIS) and a 1-layer synthetic Dual Mesh (Gore-Tex). Unoperated animals or animals undergoing primary closure (4/0 polyglecaprone) served as age-matched controls. 60 (n = 25) resp. 90 (n = 17) days later, animals underwent chest x-ray and obduction for gross examination of explants, scoring of adhesion and inflammatory response. Also, uniaxial tensiometry was done, comparing explants to contralateral native diaphragmatic tissue. Results Overall weight nearly doubled from 1,554±242 g at surgery to 2,837±265 g at obduction (+84%). X-rays did show rare elevation of the left diaphragm (SIS = 1, Gore-Tex = 1, unoperated control = 1), but no herniation of abdominal organs. 56% of SIS and 10% of Matricel patches degraded with visceral bulging in four (SIS = 3, Matricel = 1). Adhesion scores were limited: 0.5 (Matricel) to 1 (SIS, Gore-Tex) to the left lung (p = 0.008) and 2.5 (Gore-Tex), 3 (SIS) and 4 (Matricel) to the liver (p<0.0001). Tensiometry revealed a reduced bursting strength but normal compliance for SIS. Compliance was reduced in Matricel and Gore-Tex (p<0.01). Inflammatory response was characterized by a more polymorphonuclear cell (SIS) resp. macrophage (Matricel) type of infiltrate (p<0.05). Fibrosis was similar for all groups, except there was less mature collagen deposited to Gore-Tex implants (p<0.05). Conclusions Matricel induced a macrophage-dominated inflammatory response, more adhesions, had appropriate strength but a
High-accuracy fiber optical microphone in a DBR fiber laser based on a nanothick silver diaphragm by self-mixing technique.
Du, Zhengting; Lu, Liang; Zhang, Wenhua; Yang, Bo; Wu, Shuang; Zhao, Yunhe; Xu, Feng; Wang, Zhiping; Gui, Huaqiao; Liu, Jianguo; Yu, Benli
A high-accuracy fiber optical microphone (FOM) is first applied by self-mixing technique in a DBR fiber laser based on a nanothick silver diaphragm. The nanothick silver diaphragm fabricated by the convenient and low cost electroless plating method is functioned as sensing diaphragm due to critically susceptible to the air vibration. Simultaneously, micro-vibration theory model of self-mixing interference fiber optical microphone is deduced based on quasi-analytical method. The dynamic property to frequencies and amplitudes are experimentally carried out to characterize the fabricated FOM and also the reproduced sound of news and music can clearly meet the ear of the people which shows the technique proposed in this paper guarantee steady, high signal-noise ratio operation and outstanding accuracy in the DBR fiber laser which is potential to medical and security applications such as real-time voice reproduction for throat and voiceprint verification. PMID:24514635
Occurrence of fenestral diaphragms and knots in renal glomerular endothelia of diabetic mutant MafA-/-MafK+ mice as revealed in embedment-free transmission electron microscopy.
Chaiciwamongkol, Kowit; Toomsan, Yanyong; Arnanteerakul, Tansita; Kondo, Hisatake; Hipkaeo, Wiphawi
Using the advantages (high contrast and transparency and efficient 3D viewing) of embedment-free section transmission electron microscopy (TEM), the occurrence of numerous fenestral diaphragms was clearly shown in 3D en-face viewing of the renal glomerular capillary endothelium of severe overt diabetes mellitus mice, which were generally MafA-deficient and simultaneously MafK-overexpressed specifically in pancreatic β-cells. This presents another example of nephritis-induced diaphragmed fenestrae in the renal glomerular endothelium. In addition, knot-/umbilicus-like structures discrete from and larger than the central knots of regular diaphragms of fenestrated endothelium were clearly demonstrated to occur randomly in the renal glomerular endothelial fenestrae of mutant mice and wild ones. The knot-structures were revealed to be protrusions of underlining basement lamina in conventional TEM by section-tilting observation. PMID:25582093
Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial
Anand, R.
Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic
Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial.
Alaparthi, Gopala Krishna; Augustine, Alfred Joseph; Anand, R; Mahale, Ajith
Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic
SU-E-J-140: Availability of Using Diaphragm Matching in Stereotactic Body Radiotherapy (SBRT) at the Time in Breath-Holding SBRT for Liver Cancer
Kawahara, D; Tsuda, S.; Ozawa, S; Ohno, Y.; Kimura, T.; Nagata, Y.; Nakashima, T.; Aita, M.; Ochi, Y.; Okumura, T.; Masuda, H.
Purpose: IGRT based on the bone matching may produce a larger target positioning error in terms of the reproducibility of the expiration breath hold. Therefore, the feasibility of the 3D image matching between planning CT image and pretreatment CBCT image based on the diaphragm matching was investigated. Methods: In fifteen-nine liver SBRT cases, Lipiodol, uptake after TACE was outlined as the marker of the tumor. The relative coordinate of the isocenter obtained by the contrast matching was defined as the reference coordinate. The target positioning difference between diaphragm matching and bone matching were evaluated by the relative coordinate of the isocenter from the reference coordinate obtained by each matching technique. In addition, we evaluated PTV margins by van Herk setup margin formula. Results: The target positioning error by the diaphragm matching and the bone matching was 1.31±0.83 and 3.10±2.80 mm in the cranial-caudal(C-C) direction, 1.04±0.95 and 1.62±1.02 mm in the anterior-posterior(A-P) direction, 0.93±1.19 and 1.12±0.94 mm in the left-right(L-R) direction, respectively. The positioning error by the diaphragm matching was significantly smaller than the bone matching in the C-C direction (p<0.05). The setup margin of diaphragm matching and bone matching that we had calculated based on van Herk margin formula was 4.5mm and 6.2mm(C-C), and 3.6mm and 6.3mm(A-P), and 2.6mm and 4.5mm(L-R), respectively. Conclusion: IGRT based on a diaphragm matching could be one alternative image matching technique for the positioning of the patients with liver tumor.
Lentz GM. Anatomic defects of the abdominal wall and pelvic floor: abdominal and inguinal hernias, cystocele, urethrocele, ... uterine and vaginal prolapse: diagnosis and management. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds. ...
... Cystocele Anterior vaginal wall repair (surgical treatment of urinary incontinence) - series References Lentz GM. Anatomic defects of the ... 72. Read More Anterior Inflatable artificial sphincter Stress urinary incontinence Urinary catheters Urinary incontinence - injectable implant Urinary incontinence - ...
Hindmarsh, Mark; Salmi, Petja
Oscillons, extremely long-lived localized oscillations of a scalar field, are shown to be produced by evolving domain wall networks in {phi}{sup 4} theory in two spatial dimensions. We study the oscillons in frequency space using the classical spectral function at zero momentum, and obtain that the velocity distribution is suppressed as {gamma}{sup -2} at large Lorentz factor {gamma}, with oscillons produced up to at least {gamma}{approx}10. This leads us to speculate that oscillons are produced at cusps, regions of the domain wall travelling near the speed of light. In order to gain some insight onto the dilute oscillon 'gas' produced by the domain walls, we prepare a denser gas by filling the simulation volume with oscillons boosted in random directions. We finish the study by revisiting collisions between oscillons and between an oscillon and a domain wall, showing that in the latter case they can pass straight through with minimal distortion.
Liquid Metal Droplet and Micro Corrugated Diaphragm RF-MEMS for reconfigurable RF filters
NASA Astrophysics Data System (ADS)
Irshad, Wasim
detail and have proved pivotal to this work. The second part of the dissertation focuses on the Liquid Metal Droplet RF-MEMS. A novel tunable RF MEMS resonator that is based upon electrostatic control over the morphology of a liquid metal droplet (LMD) is conceived. We demonstrate an LMD evanescent-mode cavity resonator that simultaneously achieves wide analog tuning from 12 to 18 GHz with a measured quality factor of 1400-1840. A droplet of 250-mum diameter is utilized and the applied bias is limited to 100 V. This device operates on a principle called Electro-Wetting On Dielectric (EWOD). The liquid metal employed is a non-toxic eutectic alloy of Gallium, Indium and Tin known as Galinstan. This device also exploits interfacial surface energy and viscous body forces that dominate at nanoliter scale. We then apply our Liquid Metal Droplet (LMD) RF-MEMS architecture to demonstrate a continuously tunable electrostatic Ku-Band Filter. A 2-pole bandpass filter with measured insertion loss of less than 0.4dB and 3dB FBW of 3.4% is achieved using a Galinstan droplet of 250mum diameter and bias limited to 100V. We demonstrate that the LMD is insensitive to gravity by performing inversion and tilt experiments. In addition, we study its thermal tolerance by subjecting the LMD up to 150° C. The third part of the dissertation is dedicated to the Micro-Corrugated Diaphragm (MCD) RF-MEMS. We present an evanescent-mode cavity bandpass filter with state-of-the-art RF performance metrics like 4:1 tuning ratio from 5 to 20 GHz with less than 2dB insertion loss and 2-6% 3dB bandwidth. Micro-Corrugated Diaphragm (MCD) is a novel electrostatic MEMS design specifically engineered to provide large-scale analog deflections necessary for such continuous and wide tunable filtering with very high quality factor. We demonstrate a 1.25mm radius and 2mum thick Gold MCD which provides 30mum total deflection with nearly 60% analog range. We also present a detailed and systematic MCD design
NASA Technical Reports Server (NTRS)
2004-01-01The navigation camera on NASA's Mars Exploration Rover Opportunity took images during the rover's 285th martian day (Nov. 11, 2004) that are combined into this panorama. Opportunity had reached the base of 'Burns Cliff,' a portion of the inner wall of 'Endurance Crater.' This view shows rock layers in the wall, with a portion of Opportunity's solar array visible at the bottom right.
Clinical Features, Diagnosis, and Treatment Strategies of Gastrointestinal Diaphragm Disease Associated with Nonsteroidal Anti-Inflammatory Drugs
Wang, Yan-Zhi; Sun, Gang; Cai, Feng-Chun; Yang, Yun-Sheng
Background. To demonstrate the clinical features, diagnosis, and treatment of nonsteroidal anti-inflammatory drug- (NSAID-) induced diaphragm disease (DD). Methods. A literature search between January 1973 and August 2015 was undertaken. The clinical data of patients with NSAID-induced DD were recorded and analyzed. Results. 159 patients were included. The ratio of male to female was 1 : 2.3; the mean age was 65 ± 11 years. The most common clinical manifestations were gastrointestinal bleeding and obstruction. 121 (84%) patients took traditional NSAIDs. The durations of NSAIDs use ranged from 2 to 300 months. A majority (59.7%) of DD were seen in the small bowel, were seen secondly in the colon (30.2%), and were mainly located in the ileum (57.9%) and right colon (91.7%), respectively. 80% of patients had multiple diaphragms. 41.5% of small bowel DD were diagnosed preoperatively by capsule endoscopy and/or double-balloon enteroscopy, 52.1% at laparotomy. Nearly 75% of patients underwent surgery, endoscopic balloon dilation was performed in 22 patients, and NSAIDs were withdrawn in 53 patients. Conclusions. NSAID-induced DD is relatively rare. The small bowel is most commonly involved. Preoperative diagnosis of small bowel DD is relatively difficult. Discontinuation of the NSAIDs is recommended, surgical resection is the main treatment presently, and endoscopic balloon dilation should be considered as an alternative therapy. PMID:27118967
Computed Tomography-guided Radiofrequency Ablation for Sub-diaphragm Hepatocellular Carcinoma: Safety and Efficacy of Inducing an Artificial Pneumothorax.
Fujiwara, Hiroyasu; Arai, Yasuaki; Ishii, Hiroaki; Kanazawa, Susumu
We retrospectively evaluated the safety and efficacy of artificial pneumothorax induction to perform computed tomography (CT)-guided radiofrequency ablation (RFA) for sub-diaphragm hepatocellular carcinomas (HCCs). From June 2008 to October 2010 at our institution, 19 HCCs (16 patients) were treated using CT-guided RFA after artificial pneumothorax induction. A 23-G needle was inserted into the liver surface at a site of 2 connected pleurae without lung tissue. After a small amount of air was injected, the pleural space widened, creating a small pneumothorax. Additional air was insufflated via a newly inserted 18-G cannula to raise the lung away from the planned puncture line for RFA. The electrode was then advanced transthoracically. Ablation was performed using a cool-tip electrode with manual impedance control mode. The injected air was then aspirated as much as possible. Artificial pneumothorax was successfully induced in all cases. The average total volume of injected air in each case was 238ml. No artificial pneumothorax-related complication occurred; lung injury occurred in one case during RF electrode insertion. No local progression occurred during follow-up. Recurring HCCs were observed in eight patients. Artificial pneumothorax induction is safe and effective for CT-guided RFA of sub-diaphragm HCCs, which are difficult to locate on US. PMID:27339208
A novel fiber Bragg grating pressure sensor with the smart metal structure based on the planar diaphragm
NASA Astrophysics Data System (ADS)
Guo, Ming-jin; Liang, Lei
This study develops a novel fiber Bragg grating (FBG) pressure sensor encapsulated with the smart metal structure. The smart metal structure sensor made of welding the FBG plating a gold coat and the nickel tube together using Au-Ge solder is introduced, and the FBG is mounted on a planar diaphragm to enhance the pressure sensitivity. The diaphragm can be pressurized along one axial direction, and responds to an axial force only. The FBG sensor pressure sensitivity is derived theoretically and validated experimentally. The measured pressure sensitivity of the shift in the Bragg wavelength of our experimental sensor is about 1.68×10-4MPa-1, which is approximately 85 times higher than that can be achieved with a bare FBG. The pressure measurement precision of 0.5% over a full measurement range of 20 MPa has been achieved. The linearity of our sensor is also good, and there is almost no hysteresis effect. The temperature compensation performance of the pressure sensor is also studied.
Role of the medial medullary reticular formation in relaying vestibular signals to the diaphragm and abdominal muscles
NASA Technical Reports Server (NTRS)
Mori, R. L.; Bergsman, A. E.; Holmes, M. J.; Yates, B. J.
Changes in posture can affect the resting length of respiratory muscles, requiring alterations in the activity of these muscles if ventilation is to be unaffected. Recent studies have shown that the vestibular system contributes to altering respiratory muscle activity during movement and changes in posture. Furthermore, anatomical studies have demonstrated that many bulbospinal neurons in the medial medullary reticular formation (MRF) provide inputs to phrenic and abdominal motoneurons; because this region of the reticular formation receives substantial vestibular and other movement-related input, it seems likely that medial medullary reticulospinal neurons could adjust the activity of respiratory motoneurons during postural alterations. The objective of the present study was to determine whether functional lesions of the MRF affect inspiratory and expiratory muscle responses to activation of the vestibular system. Lidocaine or muscimol injections into the MRF produced a large increase in diaphragm and abdominal muscle responses to vestibular stimulation. These vestibulo-respiratory responses were eliminated following subsequent chemical blockade of descending pathways in the lateral medulla. However, inactivation of pathways coursing through the lateral medulla eliminated excitatory, but not inhibitory, components of vestibulo-respiratory responses. The simplest explanation for these data is that MRF neurons that receive input from the vestibular nuclei make inhibitory connections with diaphragm and abdominal motoneurons, whereas a pathway that courses laterally in the caudal medulla provides excitatory vestibular inputs to these motoneurons.
Generalized free-space diffuse photon transport model based on the influence analysis of a camera lens diaphragm.
Chen, Xueli; Gao, Xinbo; Qu, Xiaochao; Chen, Duofang; Ma, Xiaopeng; Liang, Jimin; Tian, Jie
The camera lens diaphragm is an important component in a noncontact optical imaging system and has a crucial influence on the images registered on the CCD camera. However, this influence has not been taken into account in the existing free-space photon transport models. To model the photon transport process more accurately, a generalized free-space photon transport model is proposed. It combines Lambertian source theory with analysis of the influence of the camera lens diaphragm to simulate photon transport process in free space. In addition, the radiance theorem is also adopted to establish the energy relationship between the virtual detector and the CCD camera. The accuracy and feasibility of the proposed model is validated with a Monte-Carlo-based free-space photon transport model and physical phantom experiment. A comparison study with our previous hybrid radiosity-radiance theorem based model demonstrates the improvement performance and potential of the proposed model for simulating photon transport process in free space. PMID:20935713
Numerical study of a novel micro-diaphragm flow channel with piezoelectric device for proton exchange membrane fuel cells
NASA Astrophysics Data System (ADS)
Ma, H. K.; Huang, S. H.; Chen, B. R.; Cheng, L. W.
Previous studies have shown that the amplitude of the vibration of a piezoelectric (PZT) device produces an oscillating flow that changes the chamber volume along with a curvature variation of the diaphragm. In this study, an actuating micro-diaphragm with piezoelectric effects is utilized as an air-flow channel in proton exchange membrane fuel cell (PEMFC) systems, called PZT-PEMFC. This newly designed gas pump, with a piezoelectric actuation structure, can feed air into the system of an air-breathing PEMFC. When the actuator moves outward to increase the cathode channel volume, the air is sucked into the chamber; moving inward decreases the channel's volume and thereby compresses air into the catalyst layer and enhancing the chemical reaction. The air-standard PZT-PEMFC cycle is proposed to describe an air-breathing PZT-PEMFC. A novel design for PZT-PEMFCs has been proposed and a three-dimensional, transitional model has been successfully built to account for its major phenomena and performance. Moreover, at high frequencies, PZT actuation leads to a more stable current output, more drained water, higher sucked air, higher hydrogen consumption, and also overcomes concentration losses.
Conducting Wall Hall Thrusters
NASA Technical Reports Server (NTRS)
Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon
A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.
Schneider, H.M.; Lux, A.E.; Howes, D.R. )
This report describes research conducted to determine the performance of HVDC wall bushings in different wetting conditions. The in-service behavior of these wall bushing on HVDC systems at voltages of {plus minus}450 kV and above is first described to establish the conditions under which flashovers have occurred. Laboratory tests made at the EPRI High Voltage Transmission Research Center confirm that wall bushings may flash over at rated operation voltage under conditions which are intended to be representative of those experienced on operating transmission systems. Methods for improving performance are discussed, and results of tests with several types of mitigation techniques are described. The major emphasis is placed on the application of room temperature vulcanized (RTV) silicone rubber. Clean fog is used to evaluate the characteristics of this material on post insulators. The encouraging performance of the post insulators coated with RTV is the basis for further evaluation on full scale wall bushings tested in nonuniform rain. In addition to tests on RTV coated wall bushings without pre-doposited contamination, attempts at achieving reasonable contamination layers on RV are described. By means of resistance measurements on horizontal insulators, the critical conditions which may lead to flashover on surfaces with different materials and coatings are investigated 15 refs., 39 figs., 11 tabs.
Ultimate Cost of Building Walls.
ERIC Educational Resources Information Center
Grimm, Clayford T.; Gross, James G.
The need for economic analysis of building walls is discussed, and the factors influencing the ultimate cost of exterior walls are studied. The present worth method is used to analyze three types of exterior non-loadbearing panel or curtain walls. Anticipated costs are expressed in terms of their present value per square foot of wall area. The…
Aines, Roger D.; Newmark, Robin L.; Knauss, Kevin G.
A thermal treatment wall emplaced to perform in-situ destruction of contaminants in groundwater. Thermal destruction of specific contaminants occurs by hydrous pyrolysis/oxidation at temperatures achievable by existing thermal remediation techniques (electrical heating or steam injection) in the presence of oxygen or soil mineral oxidants, such as MnO.sub.2. The thermal treatment wall can be installed in a variety of configurations depending on the specific objectives, and can be used for groundwater cleanup, wherein in-situ destruction of contaminants is carried out rather than extracting contaminated fluids to the surface, where they are to be cleaned. In addition, the thermal treatment wall can be used for both plume interdiction and near-wellhead in-situ groundwater treatment. Thus, this technique can be utilized for a variety of groundwater contamination problems.
Musculoskeletal chest wall pain
Fam, Adel G.; Smythe, Hugh A.
The musculoskeletal structures of the thoracic wall and the neck are a relatively common source of chest pain. Pain arising from these structures is often mistaken for angina pectoris, pleurisy or other serious disorders. In this article the clinical features, pathogenesis and management of the various musculoskeletal chest wall disorders are discussed. The more common causes are costochondritis, traumatic muscle pain, trauma to the chest wall, "fibrositis" syndrome, referred pain, psychogenic regional pain syndrome, and arthritis involving articulations of the sternum, ribs and thoracic spine. Careful analysis of the history, physical findings and results of investigation is essential for precise diagnosis and effective treatment. ImagesFig. 3Fig. 4Fig. 5 PMID:4027804
Axion domain wall baryogenesis
Daido, Ryuji; Kitajima, Naoya; Takahashi, Fuminobu
We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.
The Diaphragm and Lubricant Gel for Prevention of Cervical Sexually Transmitted Infections: Results of a Randomized Controlled Trial
Ramjee, Gita; van der Straten, Ariane; Chipato, Tsungai; de Bruyn, Guy; Blanchard, Kelly; Shiboski, Stephen; Cheng, Helen; Montgomery, Elizabeth; Padian, Nancy
Background We evaluated the effectiveness of the Ortho All-Flex Diaphragm, lubricant gel (Replens®) and condoms compared to condoms alone on the incidence of chlamydial and gonococcal infections in an open-label randomized controlled trial among women at risk of HIV/STI infections. Methods We randomized 5045 sexually-active women at three sites in Southern Africa. Participants who tested positive for curable STIs were treated prior to enrollment as per local guidelines. Women were followed quarterly and tested for Chlamydia trachomatis (CT) or Neisseria gonorrhoeae (GC) infection by nucleic-acid amplification testing (Roche Amplicor®) using first-catch urine specimens. STIs detected at follow-up visits were treated. We compared the incidence of first infection after randomization between study arms in both intent-to-treat (ITT) and per-protocol populations. Findings Baseline demographic, behavioral and clinical characteristics were balanced across study arms. Nearly 80% of participants were under 35 years of age. Median follow-up time was 21 months and the retention rate was over 93%. There were 471 first chlamydia infections, 247 in the intervention arm and 224 in the control arm with an overall incidence of 6.2/100 woman-years (wy) (relative hazard (RH) 1.11, 95% Confidence Interval (CI): 0.93–1.33; p = 0.25) and 192 first gonococcal infections, 95 in the intervention arm and 97 in the control arm with an overall incidence of 2.4/100wy (RH 0.98, 95%CI: 0.74–1.30; p = 0.90). Per protocol results indicated that when diaphragm adherence was defined as "always use" since the last visit, there was a significant reduction in the incidence of GC infection among women randomized to the intervention arm (RH 0.61, 95%CI: 0.41–0.91, P = 0.02). Interpretation There was no difference by study arm in the rate of acquisition of CT or GC. However, our per-protocol results suggest that consistent use of the diaphragm may reduce acquisition of GC. Trial
Replace the Carburetor Diaphragm. Pulsa-Jet Style with Automatic Choke. Fuel System. Student Manual 2. Small Engine Repair Series. First Edition.
ERIC Educational Resources Information Center
Hill, Pamela
This student manual, part of a small-engine repair series on servicing fuel systems, is designed for use by special needs students in Texas. The manual explains in pictures and short sentences, written on a low reading level, the job of replacing carburetor diaphragms. Along with the steps of this repair job, specific safety and caution…
One stage resection of spontaneous rupture of hepatocellular carcinoma in the triangular ligament with diaphragm invasion: case report and review of the literature
A spontaneous rupture of hepatocellular carcinoma (HCC) can lead to extensive hemorrhage and is a rare but life-threatening event. A 58-year-old male patient with no history of trauma presented at our institution with severe epigastric pain and abdominal distension for 6 h. His blood pressure was a 60/40 mmHg, and pulse rate was 132/min. Abdominal contrast enhanced computed tomography (CT) imaging revealed a ruptured mass under the left diaphragm and fluid collection in the upper abdomen, flanks and pelvic cavity. Exploratory laparotomy confirmed the presence of an active bleeding tumor in the triangular ligament invading into the diaphragm. The tumor was resected with an appropriate diaphragm margin. The resected tumor was 5 cm in diameter and pathologically identified as hepatocellular carcinoma with a negative surgical margin. This case report shows that ruptured hepatocellular carcinoma should be considered in the differential diagnosis of non-traumatic hemoperitoneum. And it is necessary to set a surgical plan for unpredictable HCC rupture with direct diaphragm invasion. PMID:22995633
The {alpha}-particle imaging of a compressed core of microtargets in a pinhole camera with a regular multi-pinhole diaphragm
Suslov, N A
The {alpha}-particle imaging of a compressed core of microtargets using a multi-pinhole regular diaphragm is proposed. The image reconstruction technique is described. The results of the {alpha}-particle imaging of a compressed core of microtargets obtained at the 'Iskra-4' laser facility are reported. (interaction of laser radiation with matter. laser plasma)
13.56 MHz radio frequency plasma properties on hemispheric electrodes and diamond-like carbon films deposition on three-dimensional polyurethane diaphragms
Ohgoe, Yasuharu; Hirakuri, Kenji K.
The characteristics of the radio frequency (rf) plasma that could hold an entire hemispheric polyurethane diaphragm generated using the hemispheric-type electrode were investigated. The plasma states were measured using Langmuir probe. Although the common rf plasma chemical vapor deposition technique using planar electrodes makes it difficult to apply uniform plasma to three-dimensional structures, the hemispheric-type electrode process could uniformly hold a hemispheric polyurethane diaphragm at self-bias voltage. As a result, this process could uniformly keep the ion sheath on the diaphragm. In case of using this process for diamond-like carbon (DLC) film deposition, the DLC film was deposited uniformly on the diaphragm at approximately 300 nm. Besides electron temperatures and electron number of densities were similar to the behavior of common rf plasma. This means that the characteristics of plasma are kept in the same states even if the plasma form is controlled using such a hemispheric-type electrode. Based on these results, this hemispheric-type electrode process was observed to be quite applicable to three-dimensional insulator structures.
Multi-stage FEL amplifier with diaphragm focusing line as direct energy driver for inertial confinement fusion
Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N.
An FEL based energy driver for Inertial Confinement Fusion (ICF) is proposed. The key element of the scheme is free electron laser system. Novel technical solutions, namely, using of multichannel, multi-stage FEL amplifier with diaphragm focusing line, reveal a possibility to construct the FEL system operating at radiation wavelength {lambda} = 0.5 {mu}m and providing flush energy E = 1 MJ and brightness 4 x 10{sup 22} W cm{sup -2} sr{sup -1} within steering pulse duration {tau} {approximately} 0.1-2 ns. Total energy efficiency of the proposed ICF energy driver is about of 11% and repetition rate is 40 Hz. It is shown that the FEL based ICF energy driver may be constructed at the present level of accelerator technique R& D.
Series integration of the diaphragm cell transport equation when the diffusion coefficient is a function of concentration
NASA Technical Reports Server (NTRS)
Cain, Judith B.; Baird, James K.
An integral of the form, t = B0 + BL ln(Delta-c) + B1(Delta-c) + B2(Delta-c)-squared + ..., where t is the time and Delta-c is the concentration difference across the frit, is derived in the case of the diaphragm cell transport equation where the interdiffusion coefficient is a function of concentration. The coefficient, B0, is a constant of the integration, while the coefficients, BL, B1, B2,..., depend in general upon the constant, the compartment volumes, and the interdiffusion coefficient and various of its concentration derivatives evaluated at the mean concentration for the cell. Explicit formulas for BL, B1, B2,... are given.
Age-related fragmentation of the motor endplate is not associated with impaired neuromuscular transmission in the mouse diaphragm
Willadt, Silvia; Nash, Mark; Slater, Clarke R.
As mammals age, their neuromuscular junctions (NMJs) gradually change their form, acquiring an increasingly fragmented appearance consisting of numerous isolated regions of synaptic differentiation. It has been suggested that this remodelling is associated with impairment of neuromuscular transmission, and that this contributes to age-related muscle weakness in mammals, including humans. The underlying hypothesis, that increasing NMJ fragmentation is associated with impaired transmission, has never been directly tested. Here, by comparing the structure and function of individual NMJs, we show that neuromuscular transmission at the most highly fragmented NMJs in the diaphragms of old (26–28 months) mice is, if anything, stronger than in middle-aged (12–14 months) mice. We suggest that NMJ fragmentation per se is not a reliable indicator of impaired neuromuscular transmission. PMID:27094316
Differential involvement of various sources of reactive oxygen species in thyroxin-induced hemodynamic changes and contractile dysfunction of the heart and diaphragm muscles.
Elnakish, Mohammad T; Schultz, Eric J; Gearinger, Rachel L; Saad, Nancy S; Rastogi, Neha; Ahmed, Amany A E; Mohler, Peter J; Janssen, Paul M L
Thyroid hormones are key regulators of basal metabolic state and oxidative metabolism. Hyperthyroidism has been reported to cause significant alterations in hemodynamics, and in cardiac and diaphragm muscle functions, all of which have been linked to increased oxidative stress. However, the definite source of increased reactive oxygen species (ROS) in each of these phenotypes is still unknown. The goal of the current study was to test the hypothesis that thyroxin (T4) may produce distinct hemodynamic, cardiac, and diaphragm muscle abnormalities by differentially affecting various sources of ROS. Wild-type and T4 mice with and without 2-week treatments with allopurinol (xanthine oxidase inhibitor), apocynin (NADPH oxidase inhibitor), L-NIO (nitric oxide synthase inhibitor), or MitoTEMPO (mitochondria-targeted antioxidant) were studied. Blood pressure and echocardiography were noninvasively evaluated, followed by ex vivo assessments of isolated heart and diaphragm muscle functions. Treatment with L-NIO attenuated the T4-induced hypertension in mice. However, apocynin improved the left-ventricular (LV) dysfunction without preventing the cardiac hypertrophy in these mice. Both allopurinol and MitoTEMPO reduced the T4-induced fatigability of the diaphragm muscles. In conclusion, we show here for the first time that T4 exerts differential effects on various sources of ROS to induce distinct cardiovascular and skeletal muscle phenotypes. Additionally, we find that T4-induced LV dysfunction is independent of cardiac hypertrophy and NADPH oxidase is a key player in this process. Furthermore, we prove the significance of both xanthine oxidase and mitochondrial ROS pathways in T4-induced fatigability of diaphragm muscles. Finally, we confirm the importance of the nitric oxide pathway in T4-induced hypertension. PMID:25795514
Differential involvement of various sources of reactive oxygen species in thyroxin-induced hemodynamic changes and contractile dysfunction of the heart and diaphragm muscles
Elnakish, Mohammad T.; Schultz, Eric J.; Gearinger, Rachel L.; Saad, Nancy S.; Rastogi, Neha; Ahmed, Amany A.E.; Mohler, Peter J.; Janssen, Paul M.L.
Thyroid hormones are key regulators of basal metabolic state and oxidative metabolism. Hyperthyroidism has been reported to cause significant alterations in hemodynamics, and in cardiac and diaphragm muscle function, all of which have been linked to increased oxidative stress. However, the definite source of increased reactive oxygen species (ROS) in each of these phenotypes is still unknown. The goal of the current study was to test the hypothesis that thyroxin (T4) may produce distinct hemodynamic, cardiac, and diaphragm muscle abnormalities by differentially affecting various sources of ROS. Wild-type and T4 mice with and without 2-week treatments with allopurinol (xanthine oxidase inhibitor), apocynin (NADPH oxidase inhibitor), L-NIO (nitric oxide synthase inhibitor), or MitoTEMPO (mitochondria-targeted antioxidant) were studied. Blood pressure and echocardiography were noninvasively evaluated, followed by ex vivo assessments of isolated heart and diaphragm muscle functions. Treatment with L-NIO attenuated the T4-induced hypertension in mice. However, apocynin improved the left-ventricular (LV) dysfunction without preventing the cardiac hypertrophy in these mice. Both allopurinol and MitoTEMPO reduced the T4-induced fatigability of the diaphragm muscles. In conclusion, we show here for the first time that T4 exerts differential effects on various sources of ROS to induce distinct cardiovascular and skeletal muscle phenotypes. Additionally, we find that T4-induced LV dysfunction is independent of cardiac hypertrophy and NADPH oxidase is a key player in this process. Furthermore, we prove the significance of both xanthine oxidase and mitochondrial ROS pathways in T4-induced fatigability of diaphragm muscles. Finally, we confirm the importance of the nitric oxide pathway in T4-induced hypertension. PMID:25795514
A new method of diaphragm apex motion detection from 2D projection images of mega-voltage cone beam CT.
Chen, Mingqing; Bai, Junjie; Siochi, R Alfredo C
To present a new method of estimating 3D positions of the ipsi-lateral hemi-diaphragm apex (IHDA) from 2D projection images of mega-voltage cone beam CT (MVCBCT). The detection framework reconstructs a 3D volume from all the 2D projection images. An initial estimated 3D IHDA position is determined in this volume based on an imaging processing pipeline, including Otsu thresholding, connected component labeling and template matching. This initial position is then projected onto each 2D projection image to create a region of interest (ROI). To accurately detect the IHDA position in 2D projection space, two methods, dynamic Hough transform (DHT) and a tracking approach based on a joint probability density function (PDF) are developed. Both methods utilize a double-parabola model to fit the 2D diaphragm boundary. The 3D IHDA motion in the superior-inferior (SI) direction is estimated from the initial static 3D position and the detected 2D positions in projection space. The two Hough-based detection methods are tested on 35 MVCBCT scans from 15 patients. The detection is compared to manually identified IHDA positions in 2D projection space by three clinicians. An average and standard deviation of 4.252 ± 3.354 and 2.485 ± 1.750 mm was achieved for DHT and tracking-based approaches respectively, compared with the inter-expert variance among three experts of 1.822 ± 1.106 mm. Based on the results of the scans, the PDF tracking-based approach appears more robust than the DHT. The combination of the automatic ROI localization and the tracking-based approach is a quicker and more accurate method of extracting 3D IHDA motion from 2D projection images. PMID:23321998
Use of mouth pressure twitches induced by cervical magnetic stimulation to assess voluntary activation of the diaphragm.
de Bruin, P F; Watson, R A; Khalil, N; Pride, N B
There is a need for a simple method to assess the adequacy of diaphragm activation during voluntary inspiratory efforts in patients with suspected respiratory muscle weakness. We have compared mouth (Pmo,t), oesophageal (Poes,t) and transdiaphragmatic (Pdi,t) twitch pressure elicited by cervical magnetic stimulation (CMS) in five normal men (mean (SD) age 32.2 (1.8) yrs) on two separate study days. Single magnetic stimuli were delivered at functional residual capacity during relaxation and during graded voluntary inspiratory efforts against a closed airway. As voluntary-effort transdiaphragmatic and oesophageal pressure increased, Pdi,t and Poes,t decreased linearly (r range, respectively, 0.82-0.98 and 0.87-0.95). During relaxation, Pmo,t was unreliable due to the poor transmission of intrathoracic pressure, but during inspiratory efforts, the relation between voluntary mouth pressure and Pmo,t was also linear (r range 0.84-0.95). On average, our subjects voluntarily generated 99, 100 and 102% of the maximum transdiaphragmatic, oesophageal and mouth pressures predicted by the respective linear regression equations. Pmo,t was correlated to both Poes,t and Pdi,t during inspiratory efforts, but not during relaxation. These studies confirm that twitch pressures induced by CMS during inspiratory efforts can be assessed at the mouth in normal subjects, providing a simple and non-invasive technique for assessing diaphragm activation during voluntary inspiratory efforts. Potentially, this technique could be made more sensitive and accurate and applied to detect submaximal efforts in patients. PMID:9762798
Therapeutic Approaches in Mitochondrial Dysfunction, Proteolysis, and Structural Alterations of Diaphragm and Gastrocnemius in Rats With Chronic Heart Failure.
Barreiro, Esther; Puig-Vilanova, Ester; Marin-Corral, Judith; Chacón-Cabrera, Alba; Salazar-Degracia, Anna; Mateu, Xavier; Puente-Maestu, Luis; García-Arumí, Elena; Andreu, Antoni L; Molina, Luis
Patients with chronic heart failure (CHF) experience exercise intolerance, fatigue and muscle wasting, which negatively influence their survival. We hypothesized that treatment with either the antioxidant N-acetyl cysteine (NAC) or the proteasome inhibitor bortezomib of rats with monocrotaline-induced CHF may restore inspiratory and limb muscle mass, function, and structure through several molecular mechanisms involved in protein breakdown and metabolism in the diaphragm and gastrocnemius. In these muscles of CHF-cachectic rats with and without treatment with NAC or bortezomib (N = 10/group) and non-cachectic controls, proteolysis (tyrosine release, proteasome activities, ubiquitin-proteasome markers), oxidative stress, inflammation, mitochondrial function, myosin, NF-κB transcriptional activity, muscle structural abnormalities, and fiber morphometry were analyzed together with muscle and cardiac functions. In diaphragm and gastrocnemius of CHF-cachectic rats, tyrosine release, proteasome activity, protein ubiquitination, atrogin-1, MURF-1, NF-κB activity, oxidative stress, inflammation, and structural abnormalities were increased, while muscle and cardiac functions, myosin content, slow- and fast-twitch fiber sizes, and mitochondrial activity were decreased. Concomitant treatment of CHF-cachectic rats with NAC or bortezomib improved protein catabolism, oxidative stress, inflammation, muscle fiber sizes, function and damage, superoxide dismutase and myosin levels, mitochondrial function (complex I, gastrocnemius), cardiac function and decreased NF-κB transcriptional activity in both muscles. Treatment of CHF-cachectic animals with NAC or bortezomib attenuated the functional (heart, muscles), biological, and structural alterations in muscles. Nonetheless, future studies conducted in actual clinical settings are warranted in order to assess the potential beneficial effects and safety concerns of these pharmacological agents on muscle mass loss and wasting in
Antioxidant administration attenuates mechanical ventilation-induced rat diaphragm muscle atrophy independent of protein kinase B (PKB Akt) signalling.
McClung, J M; Kavazis, A N; Whidden, M A; DeRuisseau, K C; Falk, D J; Criswell, D S; Powers, S K
Oxidative stress promotes controlled mechanical ventilation (MV)-induced diaphragmatic atrophy. Nonetheless, the signalling pathways responsible for oxidative stress-induced muscle atrophy remain unknown. We tested the hypothesis that oxidative stress down-regulates insulin-like growth factor-1-phosphotidylinositol 3-kinase-protein kinase B serine threonine kinase (IGF-1-PI3K-Akt) signalling and activates the forkhead box O (FoxO) class of transcription factors in diaphragm fibres during MV-induced diaphragm inactivity. Sprague-Dawley rats were randomly assigned to one of five experimental groups: (1) control (Con), (2) 6 h of MV, (3) 6 h of MV with infusion of the antioxidant Trolox, (4) 18 h of MV, (5) 18 h of MV with Trolox. Following 6 h and 18 h of MV, diaphragmatic Akt activation decreased in parallel with increased nuclear localization and transcriptional activation of FoxO1 and decreased nuclear localization of FoxO3 and FoxO4, culminating in increased expression of the muscle-specific ubiquitin ligases, muscle atrophy factor (MAFbx) and muscle ring finger-1 (MuRF-1). Interestingly, following 18 h of MV, antioxidant administration was associated with attenuation of MV-induced atrophy in type I, type IIa and type IIb/IIx myofibres. Collectively, these data reveal that the antioxidant Trolox attenuates MV-induced diaphragmatic atrophy independent of alterations in Akt regulation of FoxO transcription factors and expression of MAFbx or MuRF-1. Further, these results also indicate that differential regulation of diaphragmatic IGF-1-PI3K-Akt signalling exists during the early and late stages of MV. PMID:17916612
ERIC Educational Resources Information Center
Roman, Harry T.
Students love nothing better than personalizing their space--desk, bedroom, or even their cars. This article describes a classroom challenge that gives students a chance to let their spirits soar with the invention of a new form of wall treatment. A trip to a big box store might prove to be most helpful for students to visualize their new product…
ERIC Educational Resources Information Center
Berry, Dave; Korpan, Cynthia
This paper describes the implementation of a peer observation program at the University of Victoria called the Lecture Club. The observers are not interactive during the class--they are the proverbial flies on the wall. The paper identifies the program as self-developmental, discussing the attributes of this learning-to-teach and peer-sharing…
ERIC Educational Resources Information Center
Venuti, Len Tai
During the summer, selected students of Hawaiian ancestry who have completed seventh or eighth grade participate in a boarding program with outdoor activities such as pulling taro, star gazing, and camping. The activities eliminate walls of doubt and fear and nurture self-confidence, creativity, personal growth, leadership, and cultural awareness.…
ERIC Educational Resources Information Center
Stevens, Lori
Visitors to the campus of Orland High School (OHS) will never question that they have stepped into a world of the masses: kids, activity, personalities, busyness, and playfulness--a veritable cloud of mild bedlam. The wall of ceramic faces that greets a visitor in the school office is another reminder of the organized chaos that the teachers…
NASA Technical Reports Server (NTRS)
Wilkinson, Stephen P.; Lindemann, A. Margrethe; Beeler, George B.; Mcginley, Catherine B.; Goodman, Wesley L.; Balasubramanian, R.
A variety of wall turbulence control devices which were experimentally investigated are discussed; these include devices for burst control, alteration of outer flow structures, large eddy substitution, increased heat transfer efficiency, and reduction of wall pressure fluctuations. Control of pre-burst flow was demonstrated with a single, traveling surface depression which is phase-locked to elements of the burst production process. Another approach to wall turbulence control is to interfere with the outer layer coherent structures. A device in the outer part of a boundary layer was shown to suppress turbulence and reduce drag by opposing both the mean and unsteady vorticity in the boundary layer. Large eddy substitution is a method in which streamline curvature is introduced into the boundary layer in the form of streamwise vortices. Riblets, which were already shown to reduce turbulent drag, were also shown to exhibit superior heat transfer characteristics. Heat transfer efficiency as measured by the Reynolds Analogy Factor was shown to be as much as 36 percent greater than a smooth flat plate in a turbulent boundary layer. Large Eddy Break-Up (LEBU) which are also known to reduce turbulent drag were shown to reduce turbulent wall pressure fluctuation.
Moisture Research - Optimizing Wall Assemblies
Arena, Lois; Mantha, Pallavi
In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.
DETAIL OF CROCKETT BARN WALL CONSTRUCTION, UPPER LEVEL. The wall ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
DETAIL OF CROCKETT BARN WALL CONSTRUCTION, UPPER LEVEL. The wall construction of the Crockett barn includes a layer of diagonal sheathing that is exposed on the interior. - Crockett Farm, Barn, 1056 Fort Casey Road, Coupeville, Island County, WA
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL AND EROSION ON ROAD SURFACE. - Bridalveil Fall Bridge No. 3, Spanning Bridalveil Creek on carriage road, Yosemite Village, Mariposa County, CA
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
EAST WALL OF CRYSTALLIZER WING TO THE LEFT, END WALL OF CRUSHING MILL IN CENTER. GABLE END OF BOILING HOUSE IN LEFT BACKGROUND. VIEW FROM THE SOUTH - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI
Typical Window, Interior Wall Paint Sequence, Wall Section, and Foundation ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
Typical Window, Interior Wall Paint Sequence, Wall Section, and Foundation Sections - Civilian Conservation Corps (CCC) Camp NP-5-C, Barracks No. 5, CCC Camp Historic District at Chapin Mesa, Cortez, Montezuma County, CO
High-R Walls for Remodeling. Wall Cavity Moisture Monitoring
Wiehagen, J.; Kochkin, V.
The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.
High-R Walls for Remodeling: Wall Cavity Moisture Monitoring
Wiehagen, J.; Kochkin, V.
The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
25. NORTH TRAINING WALL, EAST SECTION, SIDE WALL CONSTRUCTION, LOOKING WEST FROM A POINT ABOUT 500 FEET FROM THE MIDDLE HARBOR PARK FISHING PIER. (Panoramic view 1 of 2). - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
38. NORTHEAST ROOM, SECOND FLOOR, SOUTH WALL. ROOM COMPLETELY WALLED WITH RANDOM WIDTH BOARDS WHICH WERE PAPERED OR PLASTERED OVER. THIS WAS TYPICAL THROUGHOUT HOUSE EXCEPT FOR WOOD PANELED WALLS - John Mark Verdier House, 801 Bay & Scott Streets, Beaufort, Beaufort County, SC
The Dielectric Wall Accelerator
Caporaso, George J.; Chen, Yu-Jiuan; Sampayan, Stephen E.
The Dielectric Wall Accelerator (DWA), a class of induction accelerators, employs a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge to mass ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.
Coultas, Thomas A.
Operation of a plasma device such as a reactor for controlled thermonuclear fusion is facilitated by an improved bumper wall enclosing the plasma to smooth the flow of energy from the plasma as the energy impinges upon the bumper wall. The bumper wall is flexible to withstand unequal and severe thermal shocks and it is readily replaced at less expense than the cost of replacing structural material in the first wall and blanket that surround it.
Domain Walls with Strings Attached
Shmakova, Marina
We have constructed a bulk and brane action of IIA theory which describes a pair of BPS domain walls on S{sub 1}/Z{sub 2}, with strings attached. The walls are given by two orientifold O8-planes with coincident D8-branes and F1-D0-strings are stretched between the walls. This static configuration satisfies all matching conditions for the string and domain wall sources and has 1/4 of unbroken supersymmetry.
Molded Concrete Center Mine Wall
NASA Technical Reports Server (NTRS)
Lewis, E. V.
Proposed semiautomatic system forms concrete-foam wall along middle of coal-mine passage. Wall helps support roof and divides passage into two conduits needed for ventilation of coal face. Mobile mold and concrete-foam generator form sections of wall in place.
[Chest wall reconstruction after resection of malignant chest wall tumors].
Ayabe, H; Oka, T; Akamine, S; Takahashi, T; Nagayasu, T
Full-thickness chest wall resection is performed for complete removal of primary and secondary malignant chest wall tumors. Large defects of the chest wall after resection must be repaired to maintain adequate ventilation, to protect important intrathoracic structures, and to preserve cosmetic integrity. Various materials have been utilized over the years to replace the rigid chest wall. At present, Marlex mesh and a composite of Marlex mesh and methylmethacrylate are frequently used to reconstruct rigid chest wall defects. On the other hand, to replace the soft part of the chest wall and cover the rigid materials, pedicled muscle flaps, myocutaneous flaps, or omentum are used. Major pedicled flaps include the pectoralis major, rectus abdominis and latissimus dorsi muscular, and musculocutaneous flaps. Techniques are now available to repair any chest wall site, and to restore chest continuity in patients whose tumors are curatively resected. PMID:9656244
Left ventricular wall stress compendium.
Zhong, L; Ghista, D N; Tan, R S
Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models
Changes in sexual behavior during a safety and feasibility trial of a microbicide/diaphragm combination: an integrated qualitative and quantitative analysis.
Guest, Greg; Johnson, Laura; Burke, Holly; Rain-Taljaard, Reathe; Severy, Lawrence; von Mollendorf, Claire; Van Damme, Lut
If proven effective, vaginal microbicides and diaphragms will likely be part of a larger HIV prevention model that includes condoms and other prevention strategies. It is, therefore, important to understand how introducing new prevention methods may affect overall patterns of sexual risk behavior. Data presented were collected as part of a safety and feasibility study of ACIDFORM gel with a diaphragm among 120 women in South Africa. Interviews were administered at enrollment and months 1, 3, 5, and 6 of the trial. Focus groups were conducted at trial exit. Frequency of sex increased significantly after enrollment. This increase appears to be owing to perceived protection from HIV and greater sexual pleasure afforded by the gel. Male condom use was high overall but increased significantly from enrollment. Data suggest this is because of increased partner involvement, increased negotiating power afforded by study participation, and provision of free condoms perceived to be of high quality. PMID:17685844
Chang, S; Hagmann, C; Sikivie, P
The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is
NASA Technical Reports Server (NTRS)
6 April 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the wall of a large impact crater in Newton Basin near 41.9oS, 158.1oW. Such gullies may have formed by downslope movement of wet debris--i.e., water. Unfortunately, because the responsible fluid (if there was one) is no longer present today, only the geomorphology of the channels and debris aprons can be used to deduce that water might have been involved. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.
Overexpression of the astrocyte glutamate transporter GLT1 exacerbates phrenic motor neuron degeneration, diaphragm compromise, and forelimb motor dysfunction following cervical contusion spinal cord injury.
Li, Ke; Nicaise, Charles; Sannie, Daniel; Hala, Tamara J; Javed, Elham; Parker, Jessica L; Putatunda, Rajarshi; Regan, Kathleen A; Suain, Valérie; Brion, Jean-Pierre; Rhoderick, Fred; Wright, Megan C; Poulsen, David J; Lepore, Angelo C
A major portion of spinal cord injury (SCI) cases affect midcervical levels, the location of the phrenic motor neuron (PhMN) pool that innervates the diaphragm. While initial trauma is uncontrollable, a valuable opportunity exists in the hours to days following SCI for preventing PhMN loss and consequent respiratory dysfunction that occurs during secondary degeneration. One of the primary causes of secondary injury is excitotoxic cell death due to dysregulation of extracellular glutamate homeostasis. GLT1, mainly expressed by astrocytes, is responsible for the vast majority of functional uptake of extracellular glutamate in the CNS, particularly in spinal cord. We found that, in bacterial artificial chromosome-GLT1-enhanced green fluorescent protein reporter mice following unilateral midcervical (C4) contusion SCI, numbers of GLT1-expressing astrocytes in ventral horn and total intraspinal GLT1 protein expression were reduced soon after injury and the decrease persisted for ≥6 weeks. We used intraspinal delivery of adeno-associated virus type 8 (AAV8)-Gfa2 vector to rat cervical spinal cord ventral horn for targeting focal astrocyte GLT1 overexpression in areas of PhMN loss. Intraspinal delivery of AAV8-Gfa2-GLT1 resulted in transduction primarily of GFAP(+) astrocytes that persisted for ≥6 weeks postinjury, as well as increased intraspinal GLT1 protein expression. Surprisingly, we found that astrocyte-targeted GLT1 overexpression increased lesion size, PhMN loss, phrenic nerve axonal degeneration, and diaphragm neuromuscular junction denervation, and resulted in reduced functional diaphragm innervation as assessed by phrenic nerve-diaphragm compound muscle action potential recordings. These results demonstrate that GLT1 overexpression via intraspinal AAV-Gfa2-GLT1 delivery exacerbates neuronal damage and increases respiratory impairment following cervical SCI. PMID:24872566
A two-step load-deflection procedure applicable to extract the Young's modulus and the residual tensile stress of circularly shaped thin-film diaphragms
NASA Astrophysics Data System (ADS)
Beigelbeck, Roman; Schneider, Michael; Schalko, Johannes; Bittner, Achim; Schmid, Ulrich
We report on a novel two-step load-deflection (LD) formula and technique that enables an accurate extraction of the Young's modulus and the residual tensile stress from LD measurements on circularly shaped thin-film diaphragms. This LD relationship is derived from an adaptation of Timoshenko's plate bending theory, where the in-plane and out-of-plane deflections are approximated by series expansions. Utilizing the minimum total potential energy principle yields an infinite-dimensional system of equations which is solved analytically resulting in a compact closed-form solution. In the appendant measurement procedure, the whole transverse bending characteristic of the diaphragm as a function of the radial coordinate is recorded for different pressure loads and introduced into the novel LD equation in order to determine the elastomechanical parameters of interest. The flexibility of this approach is demonstrated by ascertaining the Young's modulus and the residual tensile stress of two disparate diaphragm materials made of either micromachined silicon or microfiltered buckypapers composed of carbon nanotube compounds.
Acute Bowel Obstruction in a Giant Recurrent Right Bochdalek's Hernia: A Report of Complication on Both Sides of the Diaphragm
Massloom, Hasan S.
Context: Diagnosis of congenital Bochdalek's hernia (BH) in adulthood is extremely rare and requires a fastidious surgical repair, the failure of which might result in a recurrence with severe complications. We report a rare case of a giant, right BH that recurred after surgical repair and was complicated with complete bowel obstruction. Case Report: A 51-year-old Saudi male, with past surgical history of laparotomy that failed to repair BH, presented to the emergency room with severe abdominal pain, vomiting, and hypovolemic shock. Computerized tomography (CT) showed an unusual picture of closed-loop bowel obstruction above and below the diaphragm. We carried out laparotomy and thoracotomy that achieved lysis of adhesions, reduction of bowel, and repair of diaphragmatic defect. Conclusion: Acute presentation of complicated BH poses a formidable challenge because of its rarity and complexity. The preferred approach for elective repair of adult BH is debatable, where surgeons—guided by hernia type and biased by their experience—recommend either laparotomy or thoracotomy. Nevertheless, a complicated, giant, recurrent BH typically requires both laparotomy and thoracotomy. PMID:27500130
Generation of dc pin-hole discharges in liquids: comparison of discharge breakdown in diaphragm and capillary configuration
NASA Astrophysics Data System (ADS)
Kozáková, Zdenka; Krčma, František; Vašíček, Michal; Hlavatá, Lucie; Hlochová, Lenka
Electrical discharges in liquids can be generated in several electrode configurations; one of them is called as a pin-hole. The discharge is created inside a small orifice in the dielectric barrier connecting two chambers filled by any conductive solution. Each chamber contains one electrode. Based on the orifice length/diameter ratio, the discharge is called as a capillary or diaphragm discharge. The present paper gives the first detailed observation of the dependence of discharge creation on the orifice shape for selected NaCl solution conductivities (250-1000 μS cm-1). As a dielectric barrier, ceramic discs with thickness varying from 0.3 to 1.5 mm were used. Diameter of one central pin-hole was in the range of 0.25-1.00 mm. The non-pulsing dc high voltage up to 2 kV with power up to 500 W was used for the presented study. The bubble theory of the discharge generation was confirmed at the set conditions.
Proteomic profiling of antisense-induced exon skipping reveals reversal of pathobiochemical abnormalities in dystrophic mdx diaphragm
Doran, Philip; Wilton, Steve D.; Fletcher, Sue; Ohlendieck, Kay
The disintegration of the dystrophin-glycoprotein complex represents the initial pathobiochemical insult in Duchenne muscular dystrophy. However, secondary changes in signalling, energy metabolism and ion homeostasis are probably the main factors that eventually cause progressive muscle wasting. Thus, for the proper evaluation of novel therapeutic approaches, it is essential to analyse the reversal of both primary and secondary abnormalities in treated muscles. Antisense oligomer-mediated exon skipping promises functional restoration of the primary deficiency in dystrophin. In this study, an established phosphorodiamidate morpholino oligomer coupled to a cell-penetrating peptide was employed for the specific removal of exon 23 in the mutated mouse dystrophin gene transcript. Using DIGE analysis, we could show the reversal of secondary pathobiochemical abnormalities in the dystrophic diaphragm following exon-23 skipping. In analogy to the restoration of dystrophin, β-dystroglycan and neuronal nitric oxide synthase, the muscular dystrophy-associated differential expression of calsequestrin, adenylate kinase, aldolase, mitochondrial creatine kinase and cvHsp was reversed in treated muscle fibres. Hence, the re-establishment of Dp427 coded by the transcript missing exon 23 has counter-acted dystrophic alterations in Ca2+-handling, nucleotide metabolism, bioenergetic pathways and cellular stress response. This clearly establishes the exon-skipping approach as a realistic treatment strategy for diminishing diverse downstream alterations in dystrophinopathy. PMID:19132684
Asymptotic dynamics of monopole walls
NASA Astrophysics Data System (ADS)
Cross, R.
We determine the asymptotic dynamics of the U(N) doubly periodic BPS monopole in Yang-Mills-Higgs theory, called a monopole wall, by exploring its Higgs curve using the Newton polytope and amoeba. In particular, we show that the monopole wall splits into subwalls when any of its moduli become large. The long-distance gauge and Higgs field interactions of these subwalls are Abelian, allowing us to derive an asymptotic metric for the monopole wall moduli space.
Dynamical domain wall and localization
NASA Astrophysics Data System (ADS)
Toyozato, Yuta; Higuchi, Masafumi; Nojiri, Shin'ichi
Based on the previous works (Toyozato et al., 2013 [24]; Higuchi and Nojiri, 2014 [25]), we investigate the localization of the fields on the dynamical domain wall, where the four-dimensional FRW universe is realized on the domain wall in the five-dimensional space-time. Especially we show that the chiral spinor can localize on the domain wall, which has not been succeeded in the past works as the seminal work in George et al. (2009) [23].
Ellison, Kenneth; Whike, Alan S.
An oven roof or wall is formed from modular panels, each of which comprises an inner fabric and an outer fabric. Each such fabric is formed with an angle iron framework and somewhat resilient tie-bars or welded at their ends to flanges of the angle irons to maintain the inner and outer frameworks in spaced disposition while minimizing heat transfer by conduction and permitting some degree of relative movement on expansion and contraction of the module components. Suitable thermal insulation is provided within the module. Panels or skins are secured to the fabric frameworks and each such skin is secured to a framework and projects laterally so as slidingly to overlie the adjacent frame member of an adjacent panel in turn to permit relative movement during expansion and contraction.
Gil, J
We have presented a highly dynamic view of the alveolar septum and its main enclosed structure, the dense capillary network. The septal or perimicrovascular interstitium is the space between alveolar epithelial sheets after exclusion of the capillary network. It contains cells, fibers, and a viscous matrix. Capillaries form a very complex network, which closely follows the geometry of the terminal airways and participates in functional adaptations of the wall, particularly septal pleating. The level of filling and configuration of different capillaries ranging from collapse to full distension are variable, depending on factors such as transmural balance of forces but also on tissular configuration. Alveolar flooding of any cause will produce an immediate change of capillary configuration and volume. PMID:6953828
Bacterial Cell Wall Components
NASA Astrophysics Data System (ADS)
Ginsberg, Cynthia; Brown, Stephanie; Walker, Suzanne
Bacterial cell-surface polysaccharides cells are surrounded by a variety of cell-surface structures that allow them to thrive in extreme environments. Components of the cell envelope and extracellular matrix are responsible for providing the cells with structural support, mediating intercellular communication, allowing the cells to move or to adhere to surfaces, protecting the cells from attack by antibiotics or the immune system, and facilitating the uptake of nutrients. Some of the most important cell wall components are polysaccharide structures. This review discusses the occurrence, structure, function, and biosynthesis of the most prevalent bacterial cell surface polysaccharides: peptidoglycan, lipopolysaccharide, arabinogalactan, and lipoarabinomannan, and capsular and extracellular polysaccharides. The roles of these polysaccharides in medicine, both as drug targets and as therapeutic agents, are also described.
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
10. VIEW OF LAMINAR-FLOW FILTER WALL NEAR SOUTH WALL OF CLEAN ROOM (102). NOTE GROUNDING CABLES NEAR BASEBOARD IN LOWER RIGHT BACKGROUND. WHITE SQUARE IN FOREGROUND IS A FLOOR DRAIN COVERED WITH TAPE. - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA
North wall, central part, showing partial partition wall at left. ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
North wall, central part, showing partial partition wall at left. This area is labeled Pioneering Research on drawing copy NV-35-B-5 (submitted with HABS No. NV-35-B) (series 2 of 4) - Bureau of Mines Metallurgical Research Laboratory, Original Building, Date Street north of U.S. Highway 93, Boulder City, Clark County, NV
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
7. INTERIOR, MAIN GARAGE, SOUTHERN WALL, FROM CLOSE TO WALL, LOOKING SOUTH, SHOWING 'GAMEWELL' FIRE ALARM TAPE CONTROL SYSTEM (TECHNOLOGY CIRCA 1910) AT CENTER, AND ENTRY TO OFFICE AT FAR RIGHT. - Oakland Naval Supply Center, Firehouse, East of Fourth Street, between A & B Streets, Oakland, Alameda County, CA
NASA Technical Reports Server (NTRS)
2001-01-01This ASTER sub-image covers a 12 x 12 km area in northern Shanxi Province, China, and was acquired January 9, 2001. The low sun angle, and light snow cover highlight a section of the Great Wall, visible as a black line running diagonally through the image from lower left to upper right. The Great Wall is over 2000 years old and was built over a period of 1000 years. Stretching 4500 miles from Korea to the Gobi Desert it was first built to protect China from marauders from the north.This image is located at 40.2 degrees north latitude and 112.8 degrees east longitude.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and
Ultrathin antibiotic walled microcapsules.
Khopade, Ajay J; Arulsudar, N; Khopade, Surekha A; Hartmann, J
Ultrathin microcapsules comprised of anionic polyelectrolytes (PE) and a polycationic aminoglycoside (AmG) antibiotic drug were prepared by depositing PE/AmG multilayers on zinc oxide (ZnO) colloid particles using the layer-by-layer self-assembly technique and subsequently dissolving the ZnO templated cores. The polyelectrolytes, dextran sulfate sodium (DxS) and poly(styrenesulfonate) (PSS), were selected owing to their different backbone structure. An aminoglycoside, tobramycin sulfate (TbS), was used for studying DxS/TbS or PSS/TbS multilayer films. The multilayer growth on ZnO cores was characterized by alternating zeta potential values that were different for the DxS/TbS and PSS/TbS multilayers due to the PE chemistry and its interaction with Zn(2+) ions. Transmission and scanning electron microscopy provide evidence of PE/TbS multilayer coating on ZnO core particles. The slow acid-decomposition of the ZnO cores using weak organic acids and the presence of sufficient quantity of Zn(2+) in the dispersion were required to produce antibiotic multilayer capsules. There was no difference in the morphological characteristics of the two types of capsules; although, the yield for [PSS/TbS](5) capsules was significantly higher than for [DxS/TbS](5) capsules which was related to the physicochemical properties of DxS/TbS/Zn(2+) and PSS/TbS/Zn(2+) complexes forming the capsule wall. The TbS quantity in the multilayer films was determined using a quartz crystal microbalance and high performance liquid chromatography techniques which showed less TbS loading in both, capsules and multilayers on planar gold substrate, than the theoretical DxS:TbS or PSS:TbS stoichiometric ratio. The decomposition of the [PE/TbS](6) multilayers was fastest in physiological buffer followed by mannitol and water. The decomposition rate of the [PSS/TbS](6) multilayers was slower than [DxS/TbS](6) monolayers. The incomplete decomposition of DxS/TbS under saline conditions suggests the major role of
New LANL Group M-7 two-stage gun: Double-diaphragm and wrap-around gas breech
Sheffield, S.A.; Martinez, A.R.
A new two-stage gun is being installed in a high explosive testing facility at Los Alamos National Laboratory for the purpose of subjecting insensitive high explosives to controlled projectile impacts so that shock-to-detonation transition can be studied in detail. This gun has been patterned after guns designed by Alois Stilp at Ernst Mach Institut (EMI) in Freiburg and Wintersweiler, Germany. Several changes were made to adapt the design to our needs. The gun has a 100-mm diameter pump tube and 33-mm and 50-mm diameter launch tubes; both pump and launch tubes are 7.6 m long. We plan to use only helium as the reservoir gas. Large hydraulic clamps hold the gun together in three places during a shot; these are located on both sides of the transition section and at the breech. These clamps make gun conversions to different setups relatively simple, i.e., the two-stage gun can be converted into a single-stage gun. A gas breech has been designed which can be operated in either wrap-around or double-diaphragm mode with a maximum operating pressure of 15,000 psi. Two-stage gun calculations indicate that in the gas breech configuration, projectile velocities up to 4 km/s can be obtained using helium in both the breech and the reservoir. The gun has been fabricated and is being installed at the present time. Testing is expected to begin in early 1993 if the startup difficulties do not become excessive.
New LANL Group M-7 two-stage gun: Double-diaphragm and wrap-around gas breech
Sheffield, S.A.; Martinez, A.R.
A new two-stage gun is being installed in a high explosive testing facility at Los Alamos National Laboratory for the purpose of subjecting insensitive high explosives to controlled projectile impacts so that shock-to-detonation transition can be studied in detail. This gun has been patterned after guns designed by Alois Stilp at Ernst Mach Institut (EMI) in Freiburg and Wintersweiler, Germany. Several changes were made to adapt the design to our needs. The gun has a 100-mm diameter pump tube and 33-mm and 50-mm diameter launch tubes; both pump and launch tubes are 7.6 m long. We plan to use only helium as the reservoir gas. Large hydraulic clamps hold the gun together in three places during a shot; these are located on both sides of the transition section and at the breech. These clamps make gun conversions to different setups relatively simple, i.e., the two-stage gun can be converted into a single-stage gun. A gas breech has been designed which can be operated in either wrap-around or double-diaphragm mode with a maximum operating pressure of 15,000 psi. Two-stage gun calculations indicate that in the gas breech configuration, projectile velocities up to 4 km/s can be obtained using helium in both the breech and the reservoir. The gun has been fabricated and is being installed at the present time. Testing is expected to begin in early 1993 if the startup difficulties do not become excessive.
Simvastatin maintains steady patterns of GFR and improves AER and expression of slit diaphragm proteins in type II diabetes.
Tonolo, G; Velussi, M; Brocco, E; Abaterusso, C; Carraro, A; Morgia, G; Satta, A; Faedda, R; Abhyankar, A; Luthman, H; Nosadini, R
The factors determining the course of glomerular filtration rate (GFR) and albumin excretion rate (AER) and the expression of mRNA of slit diaphragm (SD) and podocyte proteins in microalbuminuric, hypertensive type II diabetic patients are not fully understood. GFR, AER, and SD protein mRNA were studied in 86 microalbuminuric, hypertensive, type II diabetics at baseline and after 4-year random double-blind treatment either with 40 mg simvastatin (Group 1) or with 30 g cholestyramine (Group 2) per day. Both groups had at baseline a GFR decay per year in the previous 2-4 years of 3 ml/min/1.73 m(2). Both Groups 1 and 2 showed a significant decrease of low-density lipoprotein cholesterol levels after simvastatin and cholestyramine treatment (P<0.01). No change from base line values was observed as for hs-C-reactive protein and interleukin-6. A significant decrease of 8-hydroxydeoxyguanosine urinary excretion was observed after simvastatin treatment. GFR did not change from baseline with simvstatin, whereas a decrease was observed with cholestyramine treatment (simvastatin vs cholestyramine: -0.21 vs -2.75 ml/min/1.73 m(2), P<0.01). AER decreased in Group 1 (P<0.01), but not in Group 2 patients. Real-time polymerase chain reaction measurement of mRNA SD proteins (CD2AP, FAT, Actn 4, NPHS1, and NPHS2) significantly increased in kidney biopsy specimens after simvastatin, but not cholestyramine treatment. Simvastatin, but not cholestyramine, 4-year treatment maintains steady patterns of GFR, and improves AER and expression of SD proteins in type II diabetes, despite similar hypocholesterolemic effects in circulation. PMID:16710349
Transmitter-mediated local contracture of the endplate region of the focally innervated mouse diaphragm treated with anticholinesterase.
Hong, S. J.; Chang, C. C.
1. Local contraction of the endplate region in response to nerve stimulation was studied in isolated mouse diaphragms. In normal preparations, muscle contractions involved the whole length of the muscle fibre with rise and decay times in the order of tens of ms whether evoked with a single or train of pulses. 2. When acetylcholinesterase was inhibited with neostigmine, tetanic stimulation produced a twitch-like phasic contraction and a delayed tonic contracture. A brief train of pulse (10 ms, 300 Hz) was enough to trigger a full size tonic contracture which reached an amplitude about one tenth that of control tetanus and had a duration of about 4 s. 3. Tetanic stimulation evoked a non-propagating prolonged depolarization at the endplate region lasting for about 1 s following a few muscle action potentials. 4. mu-Conotoxin, a specific inhibitor of muscle Na+ channel, selectively abolished the phasic contraction and the muscle action potentials leaving the tonic contracture and the prolonged depolarization unaffected. 5. Both the tonic contracture and the prolonged depolarization were highly sensitive to blockade by tubocurarine (IC50 0.05-0.1 microM) and vesamicol (1 microM, an inhibitor of packaging acetylcholine into synaptic vesicles), were attenuated by increasing Ca2+ concentration and were prolonged by decreasing Ca2+. 6. The results suggest that prolonged activation of endplate nicotinic receptors by endogenously released transmitter can produce substantial contractions of the endplate region when acetylcholinesterase are inhibited. The source of Ca2+ for the contraction seems to come mainly from intracellular stores. PMID:8104646