A surge absorption circuit according to an embodiment comprises (a) an input terminal, (b) an output terminal, (c) a common terminal, (d) a mutual inductive element having a first inductive element and a second inductive element which are electromagnetically coupled to each other so as to increase each inductance, wherein one terminal of the first inductive element is connected to the input terminal, one terminal of the second inductive element is connected to the output terminal, and the other terminal of the first inductive element and the other terminal of the second inductive element are connected to each other, and (e) a surge absorption element having one terminal connected to the other terminal of the first inductive element and the other terminal of the second inductive element and the other terminal connected to the common terminal.

1. Field of the Invention
The present invention relates to a surge absorption circuit with improved high frequency characteristics.
2. Related Background of the Invention
Semiconductor devices such as IC and LSI are destroyed or degraded in characteristics by high voltage static electricity. As a countermeasure against the static electricity for the semiconductor device, a surge absorption element such as a varistor is used. The surge absorption element typically represented by a varistor has a stray capacitive component and a stray inductive component, therefore, if applied to a circuit dealing with a high speed signal, it degrades the signal.
FIG. 1 is a diagram showing a conventional surge absorption circuit to which a varistor is applied. A surge absorption circuit 200 shown in FIG. 1 has an input/output terminal 201, a common terminal 202 and a varistor 203. When an input signal with a small amplitude is input to the input/output terminal 201, the varistor 203 remains highly resistive and does not give influence on the input signal. On the other hand, when a high voltage surge enters the input/output terminal 201, the high voltage surge is forced to pass through the varistor 203 to the common terminal 202. As a result, if the surge absorption circuit 200 shown in FIG. 1 is connected to the input/output terminal of a semiconductor device, the semiconductor device is protected from a high voltage surge.
FIG. 2 is a diagram showing an equivalent circuit of a varistor. As shown in FIG. 2, a varistor can be expressed equivalently by a variable resistor 204 and a stray capacitance 205, provided in parallel between one terminal and the other terminal. The resistance value of the variable resistor 204 is large in general, and becomes small when a high voltage surge is applied, therefore, it is possible for a varistor to protect a semiconductor device from a high voltage surge. However, since there exists the stray capacitance 205, a varistor attached to the input/output side of a semiconductor device dealing with a high speed signal may be a cause of degradation of the high speed signal.
FIG. 3 is a diagram showing the calculation result of S parameters S11 and S21 of the surge absorption circuit expressed by the equivalent circuit shown in FIG. 2. FIG. 3 shows the S parameters S11 and S21 when the capacitance Cz of the stray capacitance is 1 pF, 3 pF, and 5 pF, respectively. When the stray capacitance is 5 pF, S21 begins to degrade when the frequency of a signal exceeds 100 MHz and it is no longer possible to transmit the signal. In addition, S11 also becomes large and the reflection characteristic degrades. Even when the stray capacitance is 1 pF, the same result occurs when the frequency of the signal exceeds 1 GHz. Since the stray capacitance has a tradeoff relationship to a clamping voltage and an energy durability, there has been a problem that a surge absorption element having excellent characteristic cannot be applied to the use of a high speed signal.
FIG. 4 is a diagram showing the TDR (Time Domain Reflectmetry) test result of a conventional surge absorption circuit. FIG. 4 shows TDR when the capacitance Cz of the stray capacitance is 1 pF, 3 pF, and 5 pF, respectively. An input impedance Zi for a pulse signal whose rise time and fall time are 200 ps and signal amplitude is 1 V0-p degrades to about 40 Ω when the stray capacitance is 5 pF while it is 100 Ω in the steady state. Even when the stray capacitance is 1 pF, the input impedance degrades to 80 Ω.
As described above, when a surge absorption circuit is applied to a circuit dealing with a high speed signal, it is necessary to reduce the stray capacitive component to avoid degradation in the rise characteristic and delay characteristic of a high speed signal. On the other hand, if the stray capacitive component of a surge absorption element is reduced, the clamping voltage of the surge absorption element is raised and the energy durability is reduced.
A surge absorption circuit that reduces the influence of the stray capacitive component has already been proposed. For example, by combining an inductive element and a surge absorption element, it is possible to attain impedance matching of the surge absorption circuit. FIG. 5 is a diagram showing an example of a conventional surge absorption circuit that combines two inductive elements with a varistor. In a surge absorption circuit 210 shown in FIG. 5, a series circuit in which two inductive elements 214 and 215 are connected in series is provided between an input terminal 211 and an output terminal 212 and a varistor 216 is connected between the middle point of the series circuit and a common terminal 213.
FIG. 6 is a diagram showing an example of a conventional surge absorption circuit in which an inductive element is combined with two varistors. In a surge absorption circuit 220 shown in FIG. 6, a parallel circuit having a varistor 224 and an inductive element 225 is connected to a varistor 223 in series between an input/output terminal 221 and a common terminal 222. Such a surge absorption circuit is disclosed in, for example, Japanese Patent Application Laid-open No. 2001-60838.


A semiconductor integrated circuit having a clock signal generator comprising a ring oscillator, a divider, a phase comparator, and an up-down counter. The ring oscillator provides variable oscillation frequencies determined by a sum of the delay times provided by the circuit elements constituting the oscillator. The divider divides the oscillation frequency from the ring oscillator by a specified number. The phase comparator compares the frequency of the signal from the divider with the frequency of the external clock signal. The up-down counter controls the oscillation frequency of the ring oscillator by selectively operating switches connected with the ring oscillator based on the comparison result from the comparator. The clock generator is controlled by an external clock signal to generate an internal clock signal having a higher frequency and outputs both signals. This makes it possible to constitute the semiconductor integrated circuit by using the digital integrated circuit technology alone, thereby allowing the slow operating semiconductors and fast operating semiconductors to exist on the same circuit without sacrificing the excellent characteristics of the latter.

1. Field of the Invention
The present invention relates to a semiconductor integrated circuit and, more particularly, to a semiconductor integrated circuit which is preferred to provide, by the digital circuit technology alone, a circuit for generating a clock signal having a frequency which is an integral multiple of the frequency of a clock signal given from the outside.
2. Description of the Prior Art
As already known, semiconductors constituted by using compounds consisting of two or more elements such as GaAs, InP, AlGaAs and InGaAs have come into use these days. As compared with widely used Si semiconductors, these compound semiconductors provide high-speed operations, having particular utility in ultra high-speed and high-frequency devices. However, while realizing high-speed operations, compound semiconductors present such shortcomings as having many crystalline defects caused by the electronic instability on crystalline surfaces, a low mechanical strength, and a high production cost.
These shortcomings make it difficult to provide all circuit elements necessary for constituting a circuit by using only compound semiconductors. Therefore, compound semiconductors are often used to supplement Si semiconductors in providing the characteristics which cannot be obtained from Si semiconductors alone. For these reasons, a combination of compound semiconductors and Si semiconductors are sometimes used on the same substrate constituting a circuit.
To operate an entire circuit consisting of both compound semiconductors and Si semiconductors with a single clock signal, the clock signal must have a frequency suitable for driving the Si semiconductors which operate more slowly than the compound semiconductors on the same circuit, thereby making it impossible to make the most of the excellent characteristic of the compound semiconductors, namely a high-speed operation.
A possible means for overcoming this problem to fully derive the advantage of the compound semiconductors is to operate the compound semiconductors and the Si semiconductors on the same circuit with separate clock signals.
To generate the clock signal for driving the compound semiconductors which operate more quickly than the Si semiconductors, control must be provided so that this clock signal is put in a certain relationship with the clock signal for driving the Si semiconductors.
A circuit for generating a clock signal in a certain relationship with another clock signal is generally comprised of a PLL circuit which consists of a phase comparator 1, a loop filter 2, a voltage control oscillator 3, and a 1/N divider 4 as shown in FIG. 1. However, the PLL circuit shown in FIG. 1 is an analog circuit, making it impossible to constitute the entire clock signal generating circuit by the digital integrated circuit technology alone. Consequently, integrating a circuit including a clock signal generator has heretofore required a complicated process.

Semiconductor integrated circuit having clock signal generator


A novel test procedure is used to determine the optimum programmable charge pump levels for a flash memory array in a CPLD. According to the method of the invention, an automated tester steps through all combinations of charge pump codes and attempts to program the flash memory with each combination of voltage levels. For each combination, the results of the test (pass or fail) are logged and stored into a map or array. The center of a window of passing pump codes is taken as the starting reference point. The next step is to verify the actual voltage level associated with the pump code combination corresponding to the starting reference point. The reference pump code is loaded into the device and the corresponding flash memory cell voltage levels are measured. If the measured voltage level does not fall into the preferred range, the tester automatically adjusts the level towards the preferred range by adjusting the pump codes.

CPLDs are well-known integrated circuits that may be programmed to perform various logic functions. Numerous types of memory elements may be used in CPLD architectures to provide programmability. One such memory element, known as a flash memory cell, is both electrically erasable and programmable. Program and erase are performed on a plurality of flash memory cells using either Fowler-Nordheim (F-N) Tunneling or hot electron injection for programming and F-N Tunneling for erase. Flash memories can also be In-System Programmable (ISP). An ISP device is a device that can be programmed, erased, and verified after it has been connected, such as by soldering, to the system printed circuit board. Some CPLDs don't have ISP capability and must be programmed externally (outside the system) by programming equipment.
ISP CPLDs typically have two test modes: external mode and ISP mode. External mode requires special test equipment that can externally supply the high-level voltages required to program, erase, and verify the device. In ISP mode, internal charge pumps generate the high-level voltages from the operating voltage, and no special equipment is required. Some CPLDs use programmable charge pumps to generate the voltages needed for programming, erasing, and margin verifying during ISP. Such programmable charge pumps are well known. Lee et al describe a number of illustrative programmable charge pump circuits in U.S. Pat. No. 5,661,685, entitled "Programmable Logic Device with Configurable Power Supply", and assigned to Xilinx, Inc., the assignee of the present invention. U.S. Pat. No. 5,661,685 is incorporated herein by reference.
Programmable charge pumps are designed to be adjustable so that voltage levels can be changed to compensate for process variations during fabrication, which can cause shifts in the output voltage of the charge pumps. Application of very accurate voltage levels during programming, erasing, and verifying operations is critical to the success of programming or erasing a cell. For example, to program a cell in one well-known type of CPLD, voltages are applied to the wordline (gate) of the cell as well as the cell's bitline (drain). During erase, a voltage is applied to the source side of the cell to induce tunneling of the electrons off of the floating gate. Because of the importance of these voltage levels during operation, it is critical that optimum voltage levels are set in the device. Using optimum voltage levels ensures reliability of the device and optimum programming and erase times for the user.
Process variations alter the CPLD internal voltage levels from batch to batch. Thus, CPLDs processed within a single fabrication batch may work well at specified voltage levels, while CPLDs made in other batches do not necessarily work at the same voltage levels. More specifically, CPLDs made in other fabrication batches may not work well at the initially specified voltages, and yield may be considerably lower.
Process variations may affect charge pump accuracy from batch to batch, as well as affecting optimum voltage levels for programming, erasing, and verifying the device. Therefore, there is a need for a method of determining optimum charge pump settings for a particular batch of CPLDs, and using these optimum settings for CPLDs within the batch to maximize yield.

Method and apparatus for selecting optimum levels for in-system programmable charge pumps


The invention is a remote controlled tanning bed salon that controls the operation of a plurality of tanning beds from a centrally located transceiver. A person wishing to use a tanning bed in the system will input a card having magnetic information coded onto a magnetic strip into a central unit. The central unit will read the information on the strip and determine if such information as to whether the user has already used the tanning bed within a recent time period, how much credit on the account, etc. Once the information has been verified by the central unit one of the tanning beds will be made operable by sending a message by a radio frequency signal to one of the tanning beds. Information concerning which tanning bed is to be used and the length of time of the tanning session are included in the message that is sent from the central unit.

The invention relates to the field of tanning beds having a system for automatically operating the tanning beds from a centralized unit. Such a system allows members that subscribe to the system to utilize the tanning beds by use of magnetic cards and readers that belong to the user and are used to operate one of the tanning beds. More particularly, the invention relates to the idea of controlling such a plurality of tanning beds by means of radio frequency signals that are sent from a central unit in order to control individual tanning bed units in the system. The central unit will process information from the magnetic strip cards and then enable one of the tanning beds for use by the customer.

Radio frequency communication system for communicating with a plurality of tanning beds


This invention features ring-substituted pyrrolo-β-carboline derivatives and ring-substitution and structural derivatives of 3-(1H-indol-3-yl)-1H-pyrrole-2,5-dione of formulas I–III, which are useful as neuroprotective and anti-proliferative compounds. Also disclosed are methods for the preparation of these compounds, selected biological profiles and uses of these compounds in the treatment of various neurodegenerative and inflammatory diseases of the human nervous system and in the treatment of various other proliferative disorders characterized by loss of growth or cellular differentiation control including, but not limited to, cancer and inflammation.

The regulation of cellular responses to ischemic, excitotoxic, pathogenic or chemotoxic stresses in the central and peripheral nervous systems (CNS and PNS, repectively), including for example, the brain, the spinal cord, the eye, and the peripheral sensory and motor neurons, is a major frontier of modem medicine. Neurons are non-proliferating cells whose progressive or abrupt loss can result in diseases exemplified by Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic laterial sclerosis ("ALS" or "Lou Gehrig's disease"), and stroke. These diseases and disorders are individually or collectively referred to herein as "central neurodegenerative diseases." Selected symptoms resulting from these diseases include memory loss, loss of cognitive function, loss of gross and fine motor control, and blindness. Peripheral neuronal loss or neurite damage results in sensory loss exemplified by pain or discomfort, sensorimotor defects, and paralysis.
The incidence of central neurodegenerative diseases increases with age. For example, less than 5% of the population under the age of 65 displays signs of AD. An exponential increase is observed over the age of 65, with as much as 47% of the population displaying some form of AD over the age of 85. Many factors (etiological agents) are responsible for the initiation of neurodegenerative conditions, factors as varied as genetic DNA damage or loss in the mitochondria, abnormal amyloid processing, oxidative stress following ischemia and reperfusion, and loss of neurotrophic support for the nerve cells. The mode of action ultimately underlying such irreversible neuronal loss involves programmed cell death, or apoptosis. Preventing neuronal apoptosis and neurite disfunction represents a new, broad-spectrum, approach to the treatment of progressive central neurological disorders Various other neurodegenerative diseases related to the peripheral nervous system, herein referred to as "peripheral neuropathies", are characterized by the loss of feeling, experiencing pain, and even paralysis of or in the extremities. These peripheral neuropathies result from disease states such as ALS, Multiple Sclerosis, AIDS, diabetes, and various neuropathies induced by chemotherapeutic treatments such as cisplatin, vinblastine and taxane (Taxol™ and Taxotere™) treatment for cancer therapy, and D4T for the treatment of HIV (Human Insufficiency Virus). In most of these cases, progressive loss of axonal finction occurs initially, resulting in severe symptoms, followed by the apoptotic loss of the neuron. In these cases, inhibiting neuronal apoptosis and or axonal degradation is a new approach to treating these diseases.
A recently discovered family of genes, known as the IAPs (Inhibitor of Apoptosis Proteins), potently inhibit apoptosis in most mammalian cell lines. Members of the LAP family, specifically NAIP, HIAP1,2 and XLIP, are used as survival factors by both neurons and cancer cells to resist intrinsic apoptosis.
NAIP's (Neuronal Apoptosis Inhibitory Protein) primary finction appears to be the regulation of neuronal apoptosis (Xu, D. G. et al. Nature Medicine 1997, 3, 997). NAIP is primarily expressed in neurons where it serves to protect these post-mitotic cells against environmental and metabolic stresses that lead to premature apoptosis of the neuron. Indeed, deletions in the NAIP gene were found to be causally related to the severity of the childhood genetic neuromuscular disease, Spinal Muscular Atrophy (SMA).
Enhancement of NAIP expression in the brain was achieved through the systemic in vivo administration of a neuroprotective alkaloid, K252a (for the isolation and identification of K252a see Sezaki, M. J Antibiot. 1986, 39, 1066, U.S. Pat. No. 6,020,127). In vivo studies demonstrated increased expression of NAIP in hippocampal neurons after K252a administration to rats. These results correlate well with increased protection to ischemic insults provided by this compound (see Xu, D. G. et al. Nature Medicine 1997, 3, 997). Knock-out mice lacking the expression of NAIP displayed dramatic neuronal sensitivity to such ischemic insults.
The exact mechanism by which K252a upregulates NAIP gene expression is not known. However, it is known that K252a inhibits several classes of protein kinases. The X-ray crystal structure of a closely related natural product alkaloid, staurosporine, when bound to the protein kinases CDK2 and cAPK confirmed that staurosporine acts as a competitive inhibitor for the conserved binding site of adenosine triphosphate (ATP), which is found in all known protein kinases enzymes (for a review see Toledo and Lydon Structure 1997, 5, 1551). Several groups have suggested that K252a and its structural analogues, the indolocarbazoles, also bind to the ATP binding site of various protein kinases. A large number of natural products related to the K252a structure (indolocarbazoles) also inhibit various serine-threonine protein kinases. Most of these compounds have undesirable neuronal cytotoxic effects due to their lack of kinase specificity. Non-specific kinase inhibitory compounds can interrupt the neuronal survival signaling pathways for example, by inhibiting PKB or PKC. In fact, protein kinase deregulation has been implicated as a contributing factor to various neurodegenerative disorders (Bradshaw, D. et al. Agents and Actions 1993,38, 137; Knusel B. & Hefti F. J. Neurochem. 1992, 59, 1987). This class of compounds is typified by the following compounds:

K252a displays significant neuronal cytotoxicity at moderate doses in vitro which preclude the measurement of upregulation of NAIP gene expression as a true indication of its neuroprotective mechanism in either cultured neuroblastoma cells or cerebellar granule neurons (CGN). These findings suggest that highly specific compounds will be required in order to have pharmaceutical potential in regulating pro-apoptotic action in various diseases.
Various cancers and cell lines, including colon, lung, and breast, display elevated levels of other IAPs, including HIAP1,2 and XIAP, as either mRNA and/or protein (U.S. Pat. No. 5,919,912). Scientist at Aegera Therapeutics Inc. have shown that the down-regulation of the ILAPs in cancer cells can effectively shift the chemotherapeutic dose response required to kill such cancer cells, in the case of HAIP1, or to kill cancer cells outright, in the case of XIAP (US pat application. Compounds that down-regulate the expression of these genes would therefore be useful in treating cancers. In several cases, the cytotoxic properties of the indolocarbazoles have been exploited to affect a therapeutic use in cancer eg. Staurosporine, UNC 01, Rebeccamycin and NB 506 amongst others. Specifically, UNC 01 down regulates XIAP expression in B-cell chronic lymphocytic leukemia cell lines, inducing apoptosis (Kitada, S. et al Blood 2000, 96, 393).
Indolocarbazole Alkaloids Staurosporine and K252a
Various derivatives of the natural products Staurosporine and K252a have been described for the treatment of neurodegenerative disorders. U.S. Pat. No. 6,013,646 to Roderet al. (issued Jan. 11, 2000) discloses K252a derivatives incorporating a carbon at the tetrahydrofuran oxygen position of the K252a sugar moiety prevents tau hyperphosphorylation by the direct inhibition of the ERK family of protein kinases, also known as the MAP kinases. Tau hyperphosphorylation results in the destabilization of regular microtubular organization and the formation of neurofibular tangles (Iqbal, K. et al. FEBS Lett., 1994, 349, 104; Garver, T. D. et al., J. Neurosci. Res., 1996, 44, 12). Neurofibulary tangles are associated with neurodegenerative diseases such as AD and PD. A report by Murakata, C. et al. (J. Med Chem. 1997, 40, 1863) established that the semisynthetic K252a analogue, CEP 1347, is a selective neurotrophic agent in which the undesirable TrkA and PKC inhibitory activities have been reduced, as demonstrated in a ChAt assay. Additionally, this class of compounds appears to inhibit the production of TNF-α (tumour necrosis factor), which is intimately involved in the initiation of neuronal apoptosis. At the same time CEP 1347 and related compounds upregulated the production of IL-1β (Mallamo et al, WO96/31515; Hudkins et al, WO 97/46565; Engber et al, WO97/49406). Maroney, A. C. et al. showed that CEP 1347 inhibited JNK1 activation (J. Neurosci., 1998, 18, 104).
Other indolocarbazole derivatives are disclosed by Glicksman, M. A. et aL (WO 95 07911), Lewis, M. E. (WO 94 02488), Lewis, M. E. et al. (U.S. Pat. No. 5,756,494, No. 5,741,808, and No. 5,621,101). Indolocarbazole derivatives have also been reported for use in treatment of cancer (EP 0 323 171, EP 0 643 966, U.S. Pat. No. 4,923,986, U.S. Pat. No. 4,877,776, WO 94 27982), as antimicrobial agents (Prudhomme et al, J. Antibiotics, 1994, 47, 792) and in the treatment of hypertension (Hachisu et al. Life Sciences 1989, 44, 1351).
A variety of synthetic procedures have been reported in the literature for the preparation of bis(indolyl)pyrrole-2,5-diones and indolocarbazoles. See, for example, Bit et al., J. Med. Chem., 1993, 63, 21; Bergman et al., Tetrahedron Lett., 1987,28, 4441; Davis et al., Tetrahedron Lett., 1990, 31, 2353, 5201; Faul, M. M. et al., Tetrahedron Lett, 1999, 40, 1109; Faul M M. et al. U.S. Pat. Nos. 5,859,261, 5,919,946, and 6,037,475. For a general review of the chemistry and properties of these alkaloids see Gribble, G. W.; Berthel, S. J. "Studies in Natural Products Chemistry", 1993, 12, 365. For synthetic studies see Wood, J. L. et al. J. Am. Chem. Soc. 1997, 119, 9641; and Danishefsky, S. et al J. Am. Chem. Soc. 1996, 118, 2825.
A class of indolocarbazoles having fused imidazolyl ring systems are known as the granulatimides. Iso-granulatimide has been shown to be an effective G2 check point inhibitor in p53 deficient cancer cell lines, suggesting its potential in cancer chemotherapy (PCT WO99/47522, Sep. 23 1999). Some members of this class are illustrated below.
Pyrrolo-β-Carbazole Derivatives.
Compound "a", below, represents a typical intermediate in the synthesis of certain disclosed pyrrolo-β-carboline compounds, and was reported by Davis et al. (J. Med. Chem., 1992, 35, 177) as an inhibitor of PKC. This compound was prepared using a different chemistry than that of the instant invention, and has not been further elaborated or cyclized.

Compound "b", above, has been proposed as an undesirable, unstable intermediate in the synthesis of staurosporine aglycone. The compound was not isolated or further elaborated (Wood, J. L. et al., J. Am. Chem. Soc., 1997, 119, 9641).
A variety of synthetic procedures have been reported in the literature for the preparation of 3-(1H-indol-3-yl)-1H-pyrrole-2,5-diones involving the condensation of indole with maleimide (Bergman, J. et al. Tetrahedron, 1999, 55). Most of these synthetic procedures have distinct limitations with regards to the use of harsh reaction conditions, thereby limiting the functional groups tolerated during the coupling reactions, the need for protection of the pyrrole-2,5-dione nitrogen, and the total number of synthetic steps required for the preparation of the desired indolocarbazole nuclei.

Neuroprotective and anti-proliferative compounds


A tool for mounting a flexible slotted sleeve to hold more than one cable/wire together. The sleeve includes repetitive cuts cooperatively positioned to enhance the flexibility of the sleeve. The tool includes a slotted tubular member with a longitudinal slot through which the wires and cables are passed to be temporarily received within the slotted tubular member. A cylindrical member is mounted to the slotted tubular member, at an angle, with a distal rounded closed end and an open end that coincides into one of the open ends of the slotted tubular member. As the slotted sleeve is brought against the rounded closed end, its slot is opened and travels open towards the open end where the cables are. After leaving the open end of the slotted tubular member, the slotted sleeve is released embracing the cables to be protected.

1. Field of the Invention
The present invention relates to an apparatus for mounting a flexible cable sleeve over more than one cable or wire for removably holding them.
2. Description of the Related Art.
Applicant is not aware of the existence of an apparatus for inserting the cables to be protected within a sleeve.
Applicant knows of the existence of cable ducts, channels and surface raceways mountable to the base of walls and partitions for conventional wire enclosure applications, including telecommunication cabling. These cable ducts and raceways may be opened by removing the outer sections to allow the removal and insertion of cables. These cable ducts and raceways are permanent fixtures and do not typically allow the incorporation of cables from conventional electrical household appliances which are shorted in length. The appliances' loose cables such as lamps, speakers, audio/visual equipment, computers, printers, etc., represent a potential safety hazard when located near radiators, over floors or trapped under furniture. Several sleeve assemblies have been designed in the past for holding cables. However, there is no suitable device for releasably mounting an enclosure for cables. The cable enclosures of the prior art are not flexible, making it difficult to rotate the protected cables.
Applicant believes that a related references corresponds to French Patent No. 2,699,013, issued to Jean-Claude Douchet on Jun. 10, 1994, for an annular shaped raceway for the accommodation of electrical cables, formed with readily detachable components. However, it differs from the present invention because Douchet's patented invention does not provide for an apparatus for the insertion of cables within the sleeve as in the present invention.
Applicant believes that another related reference corresponds to French Patent No. 2,744,280, issued to Beaulat Bernard on Aug. 1, 1997 31, 1996, for a sheath for wiring bundles formed by a laminar shell wound to form a spiral to accommodate cables.
Applicant believes that another related reference corresponds to U.S. Pat. No. 4,018,983, issued to J. Watson Pedlow on Apr. 19, 1977, for a plastic tubular sheath, which, when it is longitudinally overlapped, allows the accommodation of electrical and telephone cables, and the like.
Applicant believes that another related reference corresponds to U.S. Pat. No. 6,012,494, issued to Matthias Balazs on Jan. 11, 2000, for an flexible structure, which houses and protects electrical cables.
None of these references, however, includes a device that allows the user easily mount cable sleeves to cables and wires protect them. The present invention provides for a tool to readily accomplish this.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.


A channel or chamber device having means for inhibiting flow of aqueous medium therein after the channel or chamber has been filled with aqueous medium. The device has a channel or chamber with a sample intake port at one end and an exhaust port at the other end. A restricted or reduced size chamber portion having reduced dimension (height, cross-sectional area or diameter) toward the exhaust port is provided with a water-expandable polymer in the restricted or reduced size chamber portion. The water-expandable polymer inhibits flow or forms a seal in the exhaust port when the polymer is contacted with an aqueous medium. The channel or chamber device having means for inhibiting flow of aqueous medium therein is especially adaptable to capillaries used in medical diagnostic measuring devices which contain an analytical reagent for biological fluids, such as saliva and plasma.

The present invention relates generally to capillary measuring and detecting devices, and more particularly, to a sealing device and method for the inhibition of liquid flow in capillary measuring devices, especially in capillary based diagnostic measuring devices.
Typically, the devices of the present invention have a chamber, e g., a capillary chamber or channel, which fills with a liquid by capillary and/or other action, and the liquid is metered into all parts of the device. In one such class of capillary devices, once the capillary chamber or capillary channel is filled with liquid, it is very important to inhibit or prevent further movement of the liquid. Any such movement of liquid can potentially disturb any analytical reading for which the device is used.
Capillary measuring devices are well-known and have wide utility in the field of analytical diagnosis. Capillary measuring devices are described in U.S. Pat. Nos. 5,032,506 and 5,036,000, both of which are incorporated by reference herein in their entirety. These patents describe a capillary measurement system based on a dehydrogenase based analog-to-digital switch suitable for the measurement of numerous metabolic substances, which is particularly adaptable to the measurement of alcohol from a saliva sample. A product based on this technology is commercially available from Enzymatics, Incorporated and is identified as the Q.E.D. Saliva Alcohol Test.
In U.S. Pat. No. 5,126,247 filed Feb. 26, 1988, now allowed, which is incorporated by reference herein in its entirety, there is described a method, system and device for the assay and detection of biochemical molecules. Disclosed and described therein is a capillary measuring device based on oxidation of a substrate by an enzyme capable of transferring electrons to an aromatic or anti-aromatic acceptor, which is particularly adaptable to measurement of cholesterol from a fingerstick drop of blood.
In the above-identified patents and patent application, there is a threshold gradient maintained along the capillary The capillary is filled with analytical sample without disturbing the gradient. After filling the capillary, the reagents that produce the gradient dissolve into the liquid sample and are present in a gradient along the length of the capillary. This gradient would be disturbed if the liquid stream was capable of additional movement, for example, by capillary action, and any movement of the gradient stream could result in error in the analysis determined in the analytical device. In view of the foregoing, it can be seen that it would be highly desirable to prevent such movement of the liquid in the capillary device.
In U.S Pat. No. 5,087,556, which is incorporated by reference herein in its entirety, a method is described for the quantitative analysis of body fluid constituents by a self-contained, chromatic quantitative analyzer that quantitatively detects an analyte in a biological fluid. This patent describes a base having a first open reservoir for receiving biological fluid; a means for separating solids from the biological fluid in the first open reservoir; a channel for drawing by capillary and/or wicking action, the biological fluid from the first open reservoir to a second open reservoir, wherein the second open reservoir draws the biological fluid from the channel, and, when the second open reservoir is full of biological fluid, the capillary and/or wicking action terminates. The means for metering the biological fluid is complex, and a "pull" compartment or a second open reservoir filled with an absorbent is used as the means for metering the biological fluid. The geometry, physical nature and method of incorporation of the "pull" compartment and the channel must be configured to precisely meter the volume and rate of flow of the biological fluid through the channel. Thus, this device utilizes a complex arrangement and system for precise metering.
In view of the foregoing, it can be seen that simplified metering and control systems are desirable for inhibiting or controlling the flow of liquids, for example, biological fluids, in capillary measuring devices.

Sealing device and method for inhibition of flow in capillary measuring devices


The present disclosure describes an adjustment circuit that can be used, for example, in a memory system with partitioned memory blocks. The adjustment circuit can include a controller circuit, a timer circuit, and a temperature adaptive reference (TAR) generator. The controller circuit can be configured to output a control signal that indicates a memory type (e.g., code memory or data memory) associated with a partitioned memory block. The timer circuit can be configured to output a timing signal for a read memory operation based on the control signal. And, the TAR generator can be configured to adjust a verify reference current for a verify memory operation based on temperature, where the verify reference current is set based on the control signal.

A memory device is an integral component of a computer system. For example, the memory device can be used to store computer code executed by an application running on the computer system. In another example, the memory device can be used to store data such as, for example, documents, pictures, and music. As computing demands increase, the demands on memory device density and optimization increase accordingly to meet the computing demands.

Adjustment circuit for partitioned memory block


An improved melt-blowing apparatus includes a primary air system with a plurality of air tubes and a die tip assembly having a die tip and a pair of oppositely disposed air plates. A flow-splitting device efficiently divides a stream of pressurized and heated primary air into multiple tubular flows, which are fed into air intake passages in the die tip assembly. The flow-splitting device and the air tubes are located radially outward and independent of the die body and the die tip assembly. The tubular air flows are transformed into two uniform air knives by a distribution chamber within the die tip assembly. The present primary air supply system simplifies the equipment, saves energy, improves product quality, and reduces operational and maintenance efforts.

Nonwoven substrates (also called simply "nonwovens") are webs and or three-dimensional structures of individual fibers or threads, which are interlaid but not in an identifiable manner typical of a knitted or woven substrate. Historically, nonwovens have been made by one of several different processes, such as melt blowing, spunbonding, air-laying, wet-laying, co-forming, carding, needle punching, spunlacing, and the like. The base weight of nonwovens is expressed in ounces per square yard (osy) or grams per square meter (gsm), and the fiber diameters may be measured in deniers, microns, or nanometers (ranging in size from highest to lowest). The term "mat" may be used interchangeably with the term "web" to refer to a nonwoven substrate.
Melt blowing is a major manufacturing technology for producing fibers for nonwoven webs. The term "melt blown" refers to fibers or a mat formed by extruding a molten thermoplastic material (the "melt" or the "polymer melt") through a plurality of fine orifices as molten filaments into converging flows of high-speed heated gas in a process described more fully herein.
Melt blown webs are produced by extrusion of a polymer melt, as mentioned above. The term "polymer" includes homopolymers, copolymers (such as, for example, block, graft, random and alternating copolymers), terpolymers, and blends and modifications thereof. Furthermore, the term "polymer" shall include all possible geometric configurations of the molecule. These configurations include molecules with isotactic and random symmetries.
Nonwoven webs produced by melt blowing are used in a wide variety of applications, ranging from aerospace to medical to industrial uses, where an integral protective substrate is desired or required. One exemplary product made by nonwovens is filter media.
The manufacture of nonwoven webs by melt blowing has been described in U.S. Pat. No. 3,825,380; U.S. Pat. No. 3,849,241; and U.S. Pat. No. 4,889,476, for example, as well as in numerous other publications. Generally speaking and without reference to any specific patent or other publication, the polymer is melted in an extruder and forced through a row of fine capillaries (known as "orifices" or "nozzles") to produce molten filaments. The orifices are defined through the apex of a sharp angled metal structure called the "die tip." The die tip is surrounded by two adjacent parts known as "air plates" or "air knife plates" that define a gap between the plates and the die tip that constitutes the geometry of the "air knives." Together, the die tip, the orifices, and the air plates are referred to as the "die tip assembly."
High pressure, high temperature air (the "primary air") passes through the gap between the air plates and the die tip to form the air knives. The pressure of the supplied primary air determines the blowing speed of the air knives. The air knives attenuate the molten filaments as they exit the orifices to reduce their diameters and to improve the molecular alignment of the polymer. By regulating the temperature and pressure of the primary air and polymer melt, this arrangement is capable of producing fibers of different diameter sizes, from the large micron to the sub-micron diameter range.
Specifically, the melt blowing process can be used to make fibers of various diameters, including macro fibers (average diameters from 40 to 100 microns), textile-type fibers (10 to 40 microns), microfibers (1 to 10 microns), ultra-fine microfibers (under 3 microns), submicron fibers (less than 1 micron) and nano-fibers (0.2 to 0.7 microns). Melt blown fibers may be continuous or discontinuous, and are often self-bonding when deposited onto a collecting surface.
After the molten polymer passes through the die tip orifices and is contacted by the air knives, the air-borne molten filaments begin to solidify and are cooled by unheated or cooled ambient air (referred to herein as the "cooling air" or the "secondary air") in a step known as "quenching." In addition to cooling the polymer, quenching also impacts the molecular properties of the fibers, such as crystallization. The fibers are then randomly deposited onto a collector's moving porous surface, such as a rotating drum or a conveyor belt—often assisted with suction beneath the drum or belt surface—to form a nonwoven web, mat or article with significant integrity resulting from a high degree of fiber entanglement and bond.
For making products of considerable width, a device called a "die" (or "die body") can be used to spread the hot melt flow coming from the extruder into a uniform slit flow of desired width, which is suitable to be fed into the die tip. The most advanced die type is the "coat hanger die," as described in U.S. Pat. No. 4,285,655. Other types of die bodies currently in use include a linearly tapered die, a slot die, a T-shaped die, a fishtail die, and the like.
Because of its ability to produce micro-fibers useful in a large variety of products, melt blowing technology enjoys continued popularity in industry. However, many significant shortcomings remain, many of which are documented below:
A. Melt blowing is energy intensive. Large amounts of energy are required for pressurizing, heating, and distributing the primary air streams. Mainly as a result of the design of existing melt blowing equipment, the primary air must be heated to temperatures near that of the polymer melt flow. The temperatures of the polymer melt flow in the die and the primary air must have a minimal differential in order to maintain the thermal equilibrium and homogeneous viscosity of the polymer melt. Producing a large volume of high temperature air (that is, the primary air flow) is expensive and leads to troublesome manufacturing consequences.
One consequence is that the secondary air used to quench the newly extruded fibers must be sufficiently cool and of sufficiently large volume to offset the heat of the primary air in order to effectively quench and solidify the fibers. If the secondary air is not sufficiently cool or of a sufficiently large volume, the resulting web has a harsh texture with embedded shots. "Shots" are small beads of re-melted fibers and/or polymer melt that failed to be attenuated into discrete fibers. In addition to affecting the texture of the web, shots cause the web to have poor appearance, opacity, coverage, strength, and filtration efficiency.
Another problem is that slow solidification and over-attenuation by the hot primary air may turn some fibers into "flies." Flies are tiny broken fibrous bits and pieces that escape the main fiber stream. Flies contaminate the product and the equipment, as well as causing a hazardous work environment.
Also, the consumed primary air supply undesirably heats up the manufacturing environment. As a result, it is often necessary to prepare and supply additional secondary cooling air. Ventilation, air conditioning, and air balancing means may be required during hot hours and hot days. Such additional cooling means can be costly and cumbersome.
U.S. Pat. No. 4,112,159 acknowledges some of the benefits of having cooler primary air but did not disclose a way to achieve it. U.S. Pat. No. 4,526,733 suggests using insulation between the die tip apex and the adjacent airflow for the said benefits. U.S. Pat. No. 6,336,801 suggests special heater devices and insulation to be installed on or inside the die tip apex to allow for cooler primary air flows. None of these methods has been widely accepted, because the die tip apex is only a small part of the many surface areas where thermal interference may occur and because the methods proposed are complicated and costly. Additional operation and maintenance incurred may be burdensome. More effective and simpler means to thermally separate the primary air flow and the melt flow are still needed.
B. Each polymer type has its own unique quench requirement for molecular crystallization soon after molten filaments are formed through the orifices. Meeting this requirement is important to fiber formation and its final quality. With some polymers, the necessary temperature differential between the molten filaments and the quenching air is so large that most conventional melt blowing equipment cannot maintain the requisite temperature differential. As a result, many polymer types are unsuitable for use in the currently available melt blowing equipment.
By way of example, newly developed bio-based polymers (made from organic materials or biomass) are of particular interest in medical applications, where the fiber polymer may be compounded with medicine. The resulting nonwoven web may be applied to or below the skin of a patient, such that the fibers and medicine may be dissolved and absorbed by the patient's body at a desired and controlled rate. This delivery mechanism results in a valuable medical device.
To date, the difficulty in producing this type of medical device is that the bio-based polymers have a low crystallization rate that requires a relatively large temperature differential for quenching. Since the present melt blowing equipment is unable to allow for the needed temperature differential between the primary air flow and the polymer melt flow, bio-based nonwoven substrates are expensive to produce and are available only in limited supply.
C. Conventional melt blowing equipment has low production capabilities with rigid ceilings because there are intrinsic limitations in both their melt and blowing systems. Specifically, the fine orifices at the apex of a die tip that issue molten filaments have limited structural strength to withstand melt pressure. Excessive pressure will crack the metal and allow the melt to ooze out in an uncontrolled manner. Die tip cracking is a messy and costly accident known by people in the industry as an "un-zipper." There have been many efforts to reduce this risk. For example, U.S. Pat. No. 3,825,370 teaches the use of hypodermic tubings in place of drilled orifices; U.S. Pat. No. 4,486,161 teaches the use of tie bars to reinforce the die tip; and U.S. Pat. No. 4,986,743 teaches the use of a pre-stress method to do the same. Only moderate improvement was achieved.
The conventional "blowing" system also cannot tolerate additional primary air flow because it employs the so-called "manifold" technique repeatedly (as shown in FIG. 1) to convert the primary air into air knives of usable uniformity. This technique, also known as the "reservoir" or "dissipation" method, uses sudden expansion and restriction of the flow's cross-sectional area and/or abrupt turns to reduce the momentum of the air flow in exchange for flow uniformity in the width direction (CD). The restriction and/or turning of the air flow results in a large loss of kinetic energy. When airflow exceeds the designed volume, energy consumption rises steeply, and flow uniformity deteriorates.
Good air uniformity is harder to achieve on a wide apparatus because large manifolds and pipes naturally have large Reynolds numbers, which means erratic secondary flows will co-exist with the main flow. Also, the increased width of the apparatus makes the machine bulky and clumsy in all three dimensions. U.S. Pat. No. 5,080,569 provides an effort to hold down the size for wide machines. It employs a specially configured pressure control diverter built inside the manifold and additional control dampers installed outside downstream of the manifold to manipulate the uniformity of the flow. However, in industrial practices, the benefit gained is offset by the added complexity in equipment and operation.
D. In some instances, it is desirable to produce a composite nonwoven from multiple web forming processes simultaneously. For example, it is common for spun-bonded and melt blown nonwovens to be generated in tandem to form a composite nonwoven substrate having one or more layers of each type of nonwoven. Due to the limited production capability of a conventional melt blowing apparatus, multiple units used in tandem may be used in situations only when their combined production rate can keep pace with that of the co-working process. Such examples include SMMS and SMMMS processes, where "S" stands for a spunbonding apparatus and "M" for a melt blowing apparatus. But using too many melt blowing units in tandem is costly and cumbersome. Therefore, melt blowing units capable of higher production are desirable.
In addition to higher production capability, the multi-process users also want melt blowing apparatuses to have a smaller dimension in the machine direction, preferably less than 1 meter. The present norm is 1.5 to 5 meters, depending on machine's width. The reduced machine direction dimensions occupy less factory space or permit a more generous secondary air flow system (quench air) that is beneficial to process and product quality. U.S. Pat. No. 6,972,104 presents a design for a melt blowing apparatus having reduced machine direction dimension, but requires a complicated and costly internal structure.
E. The fine orifices on the die tip get contaminated gradually by impurities and gel in the melt flow during use. This die tip contamination leads to a progressive decline of process efficiency and product quality. Scheduled and unscheduled replacements of the die tip assembly must be performed. Replacing the die tip requires first shutting down and cooling-off the entire melt blowing apparatus, followed by disassembling, replacing, reassembling, and adjusting the die tip; reheating the die body and the primary air flow; restarting and readjusting the melt blowing apparatus; and finally zeroing in on the product specifications. These many steps waste a significant amount of labor, material, and time.
A method for improvement is described in U.S. Pat. No. 5,580,581 and U.S. Pat. No. 5,632,938, in which a special die tip assembly is designed to avoid disassembly and re-assembly works on the main die body. This die tip assembly may be installed onto, and replaced from, the die body without the aforementioned cooling off and reheating steps. However, this design involves extra parts and weight, cannot allow on-line adjustment of air gap, and does not address other issues discussed in this section.
F. Air gap setting and its evenness impact product quality directly. Therefore, it is desirable to periodically check the air gap setting and to make on-line corrections, if necessary, to reduce product defects and waste. U.S. Pat. No. 4,889,476; U.S. Pat. No. 5,080,569; and U.S. Pat. No. 5,248,247 allow for such gap setting and adjustment. Unfortunately, each of the prior art approaches requires shutting down and cooling off the entire machine to replace the die tip assembly. Thus, a design that can provide both benefits (E and F) is desired.
G. Due to the common presence of fibrous "flies," the melt blowing apparatus and its surroundings need diligent and regular clean-up to avoid problems with safety, health, and product quality. To minimize flies and to facilitate cleaning, it is desirable to have an apparatus with a simpler configuration and a smaller size.
H. It is slow and expensive to build a new melt blowing apparatus. To rebuild an existing primary air system for any reason is also difficult and costly, because the air flow pathway built inside the die body and the die tip assembly is tortuous.
A more cost-effective and efficient design is desirable. Also wanted is a design that can properly process a wider range of polymer types. These improvements are likely to increase the nonwoven manufacturers' profit.
It is therefore an objective of the present invention to provide improved equipment design for the production of melt blown nonwovens. Specific goals include energy savings, simpler equipment, easier operation and maintenance, better product uniformity and quality, broader raw material choices, and smaller apparatus size.

Melt-blowing apparatus with improved primary air delivery system


An example catheter includes a handle assembly having a control member, an elongate body, a pull wire, and at least one radiopaque marker. The elongate body defines a lumen configured to receive a medical electrical lead including at least one electrode array. The elongate body includes a proximal portion coupled to the handle assembly and a distal portion that includes an articulating segment and a preformed curve segment. The at least one radiopaque marker is positioned on the distal portion. The pull wire extends from the control member and is anchored to the elongate body distal to the articulating segment such that actuation of the control member controllably bends the articulating segment in a first curve in a first geometric plane. The preformed curve segment defines a second curve in a second geometric plane different from the first geometric plane.

Specialized groups of cardiac cells that form the cardiac conduction system control the frequency, pathway of conduction, and rate of propagation of action potentials through the heart, which cause the heart to beat in an efficient manner. This special conduction system includes the sinoatrial node (SA node), the atrial internodal tracts, the atrioventricular node (AV node), the His bundle, and the right and left bundle branches.
The SA node, located at the junction of the superior vena cava and right atrium, normally acts as the natural pacemaker, generating action potentials, which are conducted through the rest of the heart. When normal conduction pathways are intact, an action potential generated in the SA node is conducted through the atria and to the AV node via the atrial internodal tracts. The conduction through the AV nodal tissue takes longer than through the atrial tissue, resulting in a delay between atrial contraction and the start of ventricular contraction.
The AV node, located in the central fibrous body, conducts the action potential to the His bundle, located above the annulus of the tricuspid valve at the crest of the ventricular muscular septum. The His bundle splits into the left and right bundle branches, which conduct the action potential to specialized fibers called "Purkinje fibers." The bundle branches rapidly conduct the action potential down the ventricular septum, where the high conduction velocity Purkinje fibers activate contractile myocardium, producing choreographed, natural physiological ventricular activation.
Conduction abnormalities may cause slowed or disrupted conduction anywhere along this conduction pathway. For example, the SA node may not generate action potentials at a fast enough rate resulting in too slow of heart rate, or bradycardia. AV block may prevent conduction of the action potential from the atria to the ventricles. A left and right bundle branch block, or other conduction abnormalities in the Purkinje fibers or ventricular myocardium, may cause the contraction of the right and left ventricles to be asynchronous. These and other conduction abnormalities may be treated by an external or implantable pacemaker.
Pacemakers are typically coupled to the heart via one or more implantable medical electrical leads, each carrying one or more electrodes for stimulating the heart and for sensing the intrinsic electrical signals associated with a conducted action potential. Electrodes are commonly placed on the endocardial surface using a transvenous approach. For example, a right ventricular lead may be advanced into the right ventricle and placed such that an electrode is positioned at or near the right ventricular apex. Low capture thresholds and stable lead positioning have made the right ventricular apex a preferred ventricular stimulation site.
However, ventricular pacing at the location of the right ventricular apex does not produce physiological ventricular activation. Both experimental and equivocal clinical studies have shown that septal pacing can improve various indices of cardiac function compared to apical pacing. Direct myocardial stimulation, as occurs in apical pacing, can cause remodeling of the ventricular myocardium, including myofibrillar disarray and local hypertrophy away from the electrode.
The most normal physiological approach to pacing the ventricles when normal AV nodal conduction fails may be to deliver electrical stimulation pulses directly to the His bundle. Depolarization of the His bundle tissue may be conducted normally through the ventricular conduction pathway, down the left and right bundle branches and to the remainder of the ventricular myocardium. The resulting ventricular contraction, which is more rapid and results in a narrow QRS complex and a more vigorous, normal contraction, may produce a better-coordinated ventricular contraction for achieving efficient heart pumping action.
Medical catheters may be advanced into vasculature of a patient to provide a lumen through which a medical device, such as a medical electrical lead, or therapeutic agent may be introduced to a treatment site. Medical catheters may be advanced to the treatment site by a clinician applying an axial force to a portion of the catheter that is outside a body of the patient. Some medical electrical leads may be configured for endocardial introduction into different chambers of a patient's heart, such as the right atrium or right ventricle, using such catheters.


Provided herein is a cost-effective and potent preservative system for a composition comprising a salicylate salt and a benzoate salt in an amount of from 0.2 weight % to 0.5 weight % by total weight of the composition and in a molar ratio of salicylate to benzoate of 1:6 to 1:1.2, wherein the composition has a pH of 5 or less. Further provided herein is a method of using a combination of a salicylate salt and a benzoate salt in a preservative system in a composition, and a method of preserving a composition.

Preservative agents are incorporated into personal care compositions such as body lotions, ointments, creams and salves, to inhibit microbial growth that may, for example, arise from contamination by the consumer when in use.
Salicylate salts are effective preservative agents. However, salicylate salts are relatively expensive to use.
Therefore, it would be desirable to provide alternative preservatives that are cost-effective and effective in inhibiting microbial growth.