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Luminal Na+/H+ exchange in the proximal tubule
The proximal tubule is critical for whole-organism volume and acid¢base homeostasis by reabsorbing filtered water, NaCl, bicarbonate, and citrate, as well as by excreting acid in the form of hydrogen and ammonium ions and producing new bicarbonate in the process. Filtered organic solutes such as amino acids, oligopeptides, and proteins are also retrieved by the proximal tubule. Luminal membrane Na+/H+ exchangers either directly mediate or indirectly contribute to each of these processes. Na+/H+ exchangers are a family of secondary active transporters with diverse tissue and subcellular distributions. Two isoforms, NHE3 and NHE8, are expressed at the luminal membrane of the proximal tubule. NHE3 is the prevalent isoform in adults, is the most extensively studied, and is tightly regulated by a large number of agonists and physiological conditions acting via partially defined molecular mechanisms. Comparatively little is known about NHE8, which is highly expressed at the lumen of the neonatal proximal tubule and is mostly intracellular in adults. This article discusses the physiology of proximal Na+/H+ exchange, the multiple mechanisms of NHE3 regulation, and the reciprocal relationship between NHE3 and NHE8 at the lumen of the proximal tubule. PMID:18853182
Bobulescu, I. Alexandru
Active Na absorption (J/sub net//sup NA/) in rabbit proximal colon in vitro is paradoxically stimulated as (Na) in the bathing media is lowered with constant osmolarity. J/sub m..-->..s//sup Na/ increases almost linearly from 0 to 50 mM (Na)/sub 0/ but then plateaus and actually decreases from 50 to 140 mM (Na)/sub 0/, consistent with inhibition of an active transport process. Both lithium and Na are equally effective inhibitors of J/sub net//sup Na/, whereas choline and mannitol do not block the high rate of J/sub net//sup Na/ observed in decreased (Na)/sub 0/. Either gluconate or proprionate replacement of Cl inhibits J/sub net//sup Na/. J/sub net//sup Na/ at lowered (Na)/sub 0/ is electrically silent and is accompanied by increased Cl absorption; it is inhibited by 10/sup -3/ M amiloride and 10/sup -3/ theophylline but not by 10/sup -4/ M bumetanide. Epinephrine is equally effective at stimulating Na absorption at 50 and 140 mM (Na). Na gradient experiments are consistent with a predominantly serosal effect of the decreased (Na)/sub 0/. These results suggest that 1) Na absorption in rabbit proximal colon in vitro is stimulated by decreased (Na); 2) the effect is cation specific, both Na and Li blocking the stimulatory effect; 3) the transport is mediated by Na-H exchange and is Cl dependent but 4) is under different regulatory mechanisms than the epinephrine-sensitive Na-Cl cotransport previously described in proximal colon. Under the appropriate conditions, proximal colon absorbs Na extremely efficiently. Na-H exchange in this epithelium is cation inhibitable, either directly or by a secondary regulatory process.
Sellin, J.H.; De Soignie, R.
Triflocin, a novel inhibitor for the Na-HCO3 symport in the proximal tubule.
1. Triflocin, applied at millimolar concentration hyperpolarizes the basolateral membrane of Necturus proximal convoluted tubular cells, in vivo. 2. Barium, 2.5 x 10(-3) M, ouabain, 10(-3) M, or amiloride 10(-4) M, fail to prevent this hyperpolarization. 3. Triflocin has no effect on the intracellular chloride activity. 4. In physiological acid base conditions, Triflocin increases intracellular pH. 5. Upon an acute isohydric hypercapnia, Triflocin depolarizes the basolateral membrane potential. 6. It is concluded that, Triflocin inhibits the basolateral electrogenic Na-(HCO3)n > 1 cotransport in proximal tubules. PMID:8075865
Belachgar, F.; Hulin, P.; Anagnostopoulos, T.; Planelles, G.
Role of the Na+/H+ antiporter in rat proximal tubule bicarbonate absorption.
Amiloride and the more potent amiloride analog, 5-(N-t-butyl) amiloride (t-butylamiloride), were used to examine the role of the Na+/H+ antiporter in bicarbonate absorption in the in vivo microperfused rat proximal convoluted tubule. Bicarbonate absorption was inhibited 29, 46, and 47% by 0.9 mM or 4.3 mM amiloride, or 1 mM t-butylamiloride, respectively. Sensitivity of the Na+/H+ antiporter to these compounds in vivo was examined using fluorescent measurements of intracellular pH with (2', 7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein (BCECF). Amiloride and t-butylamiloride were shown to be as potent against the antiporter in vivo as in brush border membrane vesicles. A model of proximal tubule bicarbonate absorption was used to correct for changes in the luminal profiles for pH and inhibitor concentration, and for changes in luminal flow rate in the various series. We conclude that the majority of apical membrane proton secretion involved in transepithelial bicarbonate absorption is mediated by the Na+-dependent, amiloride-sensitive Na+H+ antiporter. However, a second mechanism of proton secretion contributes significantly to bicarbonate absorption. This mechanism is Na+-independent and amiloride-insensitive. PMID:2888788
Preisig, P A; Ives, H E; Cragoe, E J; Alpern, R J; Rector, F C
This study was undertaken to determine whether the proximal tubule of the mud puppy Necturus maculosus possesses a basolateral Na/HCO3 cotransporter. We examined the effects on basolateral membrane potential (Vbl) and intracellular pH (pHi) of 1) lowering basolateral [HCO3-] at constant PCO2, and 2) replacing Na+ with N-methyl-D-glucamine. Vbl and pHi were measured with Ling-Gerard and liquid-membrane pH microelectrodes, respectively, in isolated tubules perfused in vitro. We found that decreasing basolateral [HCO3-] from 10 mM (pH 7.5) to 2 mM (pH 6.8) resulted in an immediate depolarization of 14.9 mV, and a pHi decrease of 0.35. SITS (4-acetamido-4'-isothiocyanostibene-2,2'-disulfonic acid, 0.5 mM) inhibited the HCO3-induced depolarization by 87% and inhibited the initial rate of the pHi decrease by 79%. Replacement of basolateral Na+ with N-methyl-D-glucamine resulted in an immediate depolarization of 11.3 mV, and a pHi decrease of 0.36. SITS inhibited the zero Na-induced depolarization by 86% and the initial rate of the pHi decrease by 81%. Nominal removal of basolateral HCO3- (replaced with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) inhibited the zero Na-induced depolarization by 64%, whereas nominal removal of Na+ inhibited the 2 mM HCO3-induced depolarization by 67%. Replacement of all basolateral Cl- with glucuronate did not inhibit the changes in Vbl induced by changing [HCO3-] or [Na+]. Observations similar to those described above have been made previously on Ambystoma proximal tubules, and attributed to an electrogenic Na/HCO3 cotransport mechanism that carries HCO3-, Na+, and net negative charge in the same direction. We conclude that Necturus proximal tubules possess a similar, if not identical, electrogenic Na/HCO3 cotransport mechanism. PMID:3618795
Lopes, A G; Siebens, A W; Giebisch, G; Boron, W F
Inhibition of Na,K-ATPase by dopamine in proximal tubule epithelial cells.
In the current report we review the results that lay grounds for the model of intracellular sodium-mediated dopamine-induced endocytosis of Na,K-ATPase. Under conditions of a high salt diet, dopamine activates PKCzeta, which phosphorylates NKA alpha1 Ser-18. The phosphorylation produces a conformational change of alpha1 NH2-terminus, which through interaction with other domains of alpha1 exposes PI3K- and AP-2-binding domains. PI3K bound to the NKA alpha1 induces the recruitment and activation of other proteins involved in endocytosis, and PI3K-generated 3-phosphoinositides affect the local cytoskeleton and modify the biophysical conditions of the membrane for development of clathrin-coated pits. Plasma membrane phosphorylated NKA is internalized to specialized intracellular compartments where the NKA will be dephosphorylated. The NKA internalization results in a reduced Na+ transport by proximal tubule epithelial cells. PMID:16139687
Pedemonte, Carlos H; Efendiev, Riad; Bertorello, Alejandro M
Tubular atrophy predicts chronic kidney disease progression, and is caused by proximal tubular epithelial cell (PTC) apoptosis. The normally quiescent Na+/H+ exchanger-1 (NHE1) defends against PTC apoptosis, and is regulated by PI(4,5)P2 binding. Because of the vast array of plasma membrane lipids, we hypothesized that NHE1-mediated cell survival is dynamically regulated by multiple anionic inner leaflet phospholipids. In membrane overlay and surface plasmon resonance assays, the NHE1 C terminus bound phospholipids with low affinity and according to valence (PIP3 > PIP2 > PIP = PA > PS). NHE1-phosphoinositide binding was enhanced by acidic pH, and abolished by NHE1 Arg/Lys to Ala mutations within two juxtamembrane domains, consistent with electrostatic interactions. PI(4,5)P2-incorporated vesicles were distributed to apical and lateral PTC domains, increased NHE1-regulated Na+/H+ exchange, and blunted apoptosis, whereas NHE1 activity was decreased in cells enriched with PI(3,4,5)P3, which localized to basolateral membranes. Divergent PI(4,5)P2 and PI(3,4,5)P3 effects on NHE1-dependent Na+/H+ exchange and apoptosis were confirmed by selective phosphoinositide sequestration with pleckstrin homology domain-containing phospholipase C? and Akt peptides, PI 3-kinase, and Akt inhibition in wild-type and NHE1-null PTCs. The results reveal an on-off switch model, whereby NHE1 toggles between weak interactions with PI(4,5)P2 and PI(3,4,5)P3. In response to apoptotic stress, NHE1 is stimulated by PI(4,5)P2, which leads to PI 3-kinase activation, and PI(4,5)P2 phosphorylation. The resulting PI(3,4,5)P3 dually stimulates sustained, downstream Akt survival signaling, and dampens NHE1 activity through competitive inhibition and depletion of PI(4,5)P2. PMID:22020933
Abu Jawdeh, Bassam G.; Khan, Shenaz; DeschĻnes, Isabelle; Hoshi, Malcolm; Goel, Monu; Lock, Jeffrey T.; Shinlapawittayatorn, Krekwit; Babcock, Gerald; Lakhe-Reddy, Sujata; DeCaro, Garren; Yadav, Satya P.; Mohan, Maradumane L.; Naga Prasad, Sathyamangla V.; Schilling, William P.; Ficker, Eckhard; Schelling, Jeffrey R.
The present study was designed to investigate the effect of administration of adrenomedullin (ADM) into subfornical organ (SFO) on renal tubular Na(+),K(+)-ATPase activity in rats. Rats under anesthesia were injected with ADM 0.1 mL (20 ng/mL) via an implanted cannula into SFO (n=6). Plasma ADM and serum endogenous digitalis-like factor (EDLF) levels were assayed with radioimmunoassay, and urine samples were collected via a canoula intubated in bladder. Urinary sodium concentration was assayed with flame spectrophotometry. Single proximal renal tubule segments were obtained by hand under stereomicroscope and its Na(+),K(+)-ATPase activity was measured by liquid scintillation counting. In addition, single proximal renal tubule segments from normal rats (n=6) were incubated with serum from animals administered with ADM into SFO, and then the Na(+),K(+)-ATPase activity was determined. The results showed that both urinary volume and sodium excretion amounted to the peak value at 30 min after ADM administration, and sustained a significant high level at 60 min (P<0.01). At 30 min after ADM administration, there was a significant increase in serum EDLF and a decrease in Na(+),K(+)-ATPase activity of proximal tubule (P<0.01, respectively), but not in plasma ADM level. Na(+),K(+)-ATPase activity was decreased significantly in single proximal renal tubule segments from normal rats incubated with serum from rats administered with ADM into SFO (P<0.01). These results suggest that the diuretic and natriuretic responses following administration of ADM into SFO are associated with the inhibition of renal tubule Na(+),K(+)-ATPase activity. The inhibition of renal tubule Na(+),K(+)-ATPase activity is related to the increase in the serum level of EDLF. PMID:19224060
Gao, Yuan; Li, Xing-Qi
All the relevant literature reports indicate that net rates of salt and water absorption and cell membrane potentials (Vb) are lower, but intracellular Na+ concentration is higher in rabbit renal proximal tubule in vitro than in rat proximal tubule in vivo. Since the different driving forces should influence basolateral Na(+)-HCO3- cotransport we have studied the operation of the cotransporter in isolated rabbit renal proximal tubule in vitro with special emphasis on the stoichiometry of flux coupling (q). Using conventional and ion-selective intracellular microelectrodes three series of experiments were performed: (a) we determined the Vb response to a 2:1 reduction of bath HCO3- or Na+ concentration, (b) we determined initial efflux rates of HCO3- or Na+ ions in response to a sudden 10:1 reduction of bath HCO3- concentration, and (c) we collapsed the tubules and determined electrochemical driving forces of Na+ and HCO3- across the basolateral cell membrane under conditions approaching zero net flux in the control state in the presence of Ba2+- and in Cl(-)-free solutions. All measurements concurrently yielded a coupling ratio of approximately two HCO3- ions to one Na+ ion (q = 2). This result contrasts with the ratio q = 3, which we have previously observed in similar experiments on rat renal proximal tubule in vivo [Yoshitomi et al. (1985) Pfl³gers Arch 405:360] and which was also observed on rabbit renal basolateral cell membrane vesicles in vitro [Soleimani et al. (1987) J Clin Invest 79:1276].(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8134258
Seki, G; Coppola, S; Fr÷mter, E
PHYSICAL REVIEW B 83, 245104 (2011) Possible proximity of the Mott insulating iridate Na2IrO3 by the recent experimental observation of a Mott insulating state for the layered iridate Na2IrO3, we discuss for the latter are the iridates.3,4 These 5d transition metal oxides are prone to exhibit electronic correlations
Trebst, Simon
This investigation was undertaken to evaluate the effect of treatment with electrolyzed NaCl solutions and 1% essential oil (0.5% carvacrol+0.5% thymol) on the proximate composition and nutritional components (amino acids and fatty acids) of carp fillets at room temperature (25░C). Carp fillet samples were treated with anodic electrolyzed NaCl solution [EW (+)], cathodic electrolyzed NaCl solution [EW (?)] followed by
Barakat S. M. Mahmoud; Y. Kawai; K. Yamazaki; K. Miyashita; T. Suzuki
Low concentrations of angiotensin II (Ang II) increase, whereas high concentrations inhibit the apical Na/H antiporter activity in the proximal tubule, but the respective roles of the different signaling pathways in mediating these effects remains unsettled. We studied the effects of both low and high doses of Ang II in the presence of selective signaling pathway inhibitors, on the apical Na/H antiport activity of rat proximal tubule. Experiments were carried out in intact cells of freshly prepared tubule fragments obtained from the outer third of cortex, that is, devoid of basolateral Na/H antiport activity in the absence of bicarbonate transport and H(+)-ATPase activity. In tubules acid-loaded by an NH4Cl prepulse, Na/H antiport activity was assessed by the initial rate of intracellular pH recovery (dpHi/dt), measured with BCECF. When tubules were preincubated with low dose Ang II (10(-11) M for 3 min), dpHi/dt increased by 25 +/- 8%, whereas incubation with high dose Ang II (10(-7) M for 3 min) decreased dpHi/dt by 30 +/- 4%, compared to control (P < 0.01 in both cases). Both effects were abolished in the presence of 2.10(-3) M amiloride. Low dose Ang II-induced increase in dpHi/dt was not affected by preincubation with a specific PKA inhibitor, Rp-CPT-cAMP 10(-4) M, and was completely abolished by preincubation with PKC inhibitors, staurosporine 10(-7) M, sphingosine 5.10(-6) M, or calphostin 10(-6) M. In addition, pretreatment of rats with pertussis toxin led to a partial inhibition of the effect of low dose Ang II. The high dose-Ang II-induced decrease in dpHi/dt was not affected by pretreatment with a calcium-calmodulin kinase inhibitor W-7 10(-4) M. Conversely, pretreatment with the cytochrome P-450 inhibitor econazole 10(-5) M reversed the inhibitory effect of high dose Ang II to a stimulatory effect (24 +/- 8%, P < 0.01), quantitatively similar to the effect of low dose Ang II. In addition, arachidonate was found to exert an econazole-sensitive dose-dependent inhibitory effect on dpHi/dt, and 5,6-EET 10(-6) M, a cytochrome P-450 derived-arachidonic acid metabolite, induced a 38 +/- 9% inhibition, similar to that observed with high dose Ang II alone. There was no additive effect of 5,6-EET and high dose Ang II. Finally, pretreatment with two PLA2 inhibitors (BromoPhenacylBromide, 6.10(-6) M, and oleyloxyethyl phosphorylcholine, 5.10(-6) M) reversed the inhibitory effect of high dose Ang II to a stimulatory effect (32 +/- 11% and 25 +/- 11%, respectively, P < 0.05 for both inhibitors). We conclude that, in intact rat proximal cells, low dose Ang II stimulates the apical Na/H antiport through a pertussis toxin-sensitive G protein-dependent PKC pathway, whereas high dose Ang II inhibits the Na/H antiport activity through the PLA2- and cytochrome P-450-dependent metabolites of arachidonate. PMID:8914015
Houillier, P; Chambrey, R; Achard, J M; Froissart, M; Poggioli, J; Paillard, M
NASA Astrophysics Data System (ADS)
To avoid large changes in cell K+ content and volume during variations in Na+, K+-ATPase activity, Na+-transporting epithelia must adjust the rate of K+ exit through passive permeability pathways. Recent studies have shown that a variety of passive K+ transport mechanisms may coexist within a cell and may be functionally linked to the activity of the Na+, K+-ATPase. In this study, we have identified three distinct pathways for passive K+ transport that act in concert with the Na+, K+-ATPase to maintain intracellular K+ homeostasis in the proximal tubule. Under control conditions, the total K+ leak of the tubules consisted of discrete Ba2+-sensitive (? 65%), quinine-sensitive (? 20%), and furosemide-sensitive (? 10%) pathways. Following inhibition of the principal K+ leak pathway with Ba2+, the tubules adaptively restored cell K+ content to normal levels. This recovery of cell K+ content was inhibited, in an additive manner, by quinine and furosemide. Following adaptation to Ba2+, the tubules exhibited a 30% reduction in Na+-K+ pump rate coupled with an increase in K+ leak by means of the quinine-sensitive (? 70%) and furosemide-sensitive (? 280%) pathways. Thus, the proximal tubule maintains intracellular K+ homeostasis by the coordinated modulation of multiple K+ transport pathways. Furthermore, these results suggest that, like Ba2+, other inhibitors of K+ conductance will cause compensatory changes in both the Na+-K+ pump and alternative pathways for passive K+ transport.
Kone, Bruce C.; Brady, Hugh R.; Gullans, Steven R.
This study evaluated the response of the Na(+)/H(+) exchanger (NHE) to dopamine D(1)- and D(2)-like receptor stimulation in immortalized renal proximal tubular epithelial cells and freshly isolated renal proximal tubules from the spontaneously hypertensive rat (SHR) and their normotensive controls (Wistar Kyoto rats; WKY). Stimulation of D(1)-like receptors with SKF 38393 attenuated NHE activity in WKY cells (IC(50)=151 nM), but not in SHR cells. Stimulation of D(2)-like receptors with quinerolane (IC(50)=120 nM) attenuated NHE activity in SHR cells, but not in WKY cells. Forskolin was equipotent in SHR and WKY cells in inhibiting NHE activity. The effect of SKF 38393 was abolished by overnight treatment of WKY cells with cholera toxin (CTX, 500 ng ml(-1)), but not with pertussis toxin (PTX, 100 ng ml(-1)). The effect of quinerolane (1 microm) was abolished by overnight treatment of SHR cells with PTX, but not with CTX. The D(3) receptor agonist 7-OH-DPAT (IC(50)=0.8 microM) attenuated NHE activity in SHR cells only. This effect was abolished by S-sulpiride and by overnight treatment with PTX. The D(4) receptor agonist RBI 257 did not affect NHE activity. The 7-OH-DPAT inhibited NHE activity in freshly isolated renal proximal tubules from 4- and 12-week-old SHR and 12-week-old WKY, but not in freshly isolated renal proximal tubules from 4-week-old WKY. It is concluded that D(3) receptors coupled to a G(i/o) protein play a role in the handling of tubular Na(+), namely through inhibition of the NHE activity, this being of particular relevance in the SHR, which fail to respond to D(1)-like dopamine receptor stimulation. PMID:15265811
Pedrosa, Rui; Gomes, Pedro; Zeng, Chunyu; Hopfer, Ulrich; Jose, Pedro A; Soares-da-Silva, PatrĒcio
The effect of chronic dietary acid on the apical membrane Na/H antiporter and basolateral membrane Na(HCO3)3 symporter was examined in the in vivo microperfused rat proximal tubule. Transporter activity was assayed with the epifluorescent measurement of cell pH using the intracellular, pH-sensitive fluorescent dye, (2'7')-bis(carboxyethyl)-(5,6)-carboxy-fluorescein (BCECF). BCECF was calibrated intracellularly, demonstrating similar pH-sensitivity of the dye in control and acidotic animals. In subsequent studies, lumen and peritubular capillaries were perfused to examine Na/H and Na(HCO3)3 transporter activity in the absence of contact with native fluid. The initial rate of change in cell pH (dpHi/dt) was 97, 50, and 44% faster in tubules from acidotic animals when peritubular [HCO3] was changed from 25 to 10 mM in the presence or absence of chloride, or peritubular [Na] was changed from 147 to 50 mM, respectively. dpHi/dt was 57% faster in tubules from acidotic animals when luminal [Na] was changed from 152 to 0 mM. Buffer capacities, measured using NH3/NH+4 addition, were similar in the two groups. The results demonstrate that chronic metabolic acidosis causes an adaptation in the intrinsic properties of both the apical membrane Na/H antiporter and basolateral membrane Na(HCO3)3 symporter. PMID:2844858
Preisig, P A; Alpern, R J
The kidney plays a fundamental role in maintaining body salt and fluid balance and blood pressure homeostasis through the actions of its proximal and distal tubular segments of nephrons. However, proximal tubules are well recognized to exert a more prominent role than distal counterparts. Proximal tubules are responsible for reabsorbing approximately 65% of filtered load and most, if not all, of filtered amino acids, glucose, solutes, and low molecular weight proteins. Proximal tubules also play a key role in regulating acid-base balance by reabsorbing approximately 80% of filtered bicarbonate. The purpose of this review article is to provide a comprehensive overview of new insights and perspectives into current understanding of proximal tubules of nephrons, with an emphasis on the ultrastructure, molecular biology, cellular and integrative physiology, and the underlying signaling transduction mechanisms. The review is divided into three closely related sections. The first section focuses on the classification of nephrons and recent perspectives on the potential role of nephron numbers in human health and diseases. The second section reviews recent research on the structural and biochemical basis of proximal tubular function. The final section provides a comprehensive overview of new insights and perspectives in the physiological regulation of proximal tubular transport by vasoactive hormones. In the latter section, attention is particularly paid to new insights and perspectives learnt from recent cloning of transporters, development of transgenic animals with knockout or knockin of a particular gene of interest, and mapping of signaling pathways using microarrays and/or physiological proteomic approaches. PMID:23897681
Zhuo, Jia L.; Li, Xiao C.
The renal electrogenic Na(+)/HCO(3)(?) cotransporter (NBCe1-A) contributes to the basolateral step of transepithelial HCO(3)(?) reabsorption in proximal tubule epithelia, contributing to the buffering of blood pH. Elsewhere in the body (e.g. muscle cells) NBCe1 variants contribute to, amongst other processes, maintenance of intracellular pH. Others have described a homozygous mutation in NBCe1 (NBCe1-A p.Ala799Val) in an individual with severe proximal renal tubular acidosis (pRTA; usually associated with defective HCO(3)(?) reabsorption in proximal tubule cells) and hypokalaemic periodic paralysis (hypoPP; usually associated with leaky cation channels in muscle cells). Using biotinylation and two-electrode voltage-clamp on Xenopus oocytes expressing NBCe1, we demonstrate that the mutant NBCe1-A (A(A799V)) exhibits a per-molecule transport defect that probably contributes towards the observed pRTA. Furthermore, we find that A(A799V) expression is associated with an unusual HCO(3)(?)-independent conductance that, if associated with mutant NBCe1 in muscle cells, could contribute towards the appearance of hypokalaemic paralysis in the affected individual. We also study three novel lab mutants of NBCe1-A: p.Ala799Ile, p.Ala799Gly and p.Ala799Ser. All three exhibit a per-molecule transport defect, but only A(A799I) exhibits an A(A799V)-like ion conductance. A(A799G) and A(A799S) exhibit unusual outward rectification in their HCO(3)(?)-dependent conductance and A(A799G) exhibits reduced sensitivity to both DIDS and tenidap. A799G is the first mutation shown to affect the apparent tenidap affinity of NBCe1. Finally we show that A(A799V) and A(A799I), which accumulate poorly in the plasma membrane of oocytes, exhibit signs of abnormal intracellular accumulation in a non-polarized renal cell-line. PMID:22331414
Parker, Mark D; Qin, Xue; Williamson, Rosalind C; Toye, Ashley M; Boron, Walter F
Na(+)-glucose cotransporter 1 (SGLT1)-mediated glucose uptake leads to activation of Na(+)-H(+) exchanger 3 (NHE3) in the intestine by a process that is not dependent on glucose metabolism. This coactivation may be important for postprandial nutrient uptake. However, it remains to be determined whether SGLT-mediated glucose uptake regulates NHE3-mediated NaHCO3 reabsorption in the renal proximal tubule. Considering that this nephron segment also expresses SGLT2 and that the kidneys and intestine show significant variations in daily glucose availability, the goal of this study was to determine the effect of SGLT-mediated glucose uptake on NHE3 activity in the renal proximal tubule. Stationary in vivo microperfusion experiments showed that luminal perfusion with 5 mM glucose stimulates NHE3-mediated bicarbonate reabsorption. This stimulatory effect was mediated by glycolytic metabolism but not through ATP production. Conversely, luminal perfusion with 40 mM glucose inhibited NHE3 because of cell swelling. Notably, pharmacologic inhibition of SGLT activity by Phlorizin produced a marked inhibition of NHE3, even in the absence of glucose. Furthermore, immunofluorescence experiments showed that NHE3 colocalizes with SGLT2 but not SGLT1 in the rat renal proximal tubule. Collectively, these findings show that glucose exerts a bimodal effect on NHE3. The physiologic metabolism of glucose stimulates NHE3 transport activity, whereas, supraphysiologic glucose concentrations inhibit this exchanger. Additionally, Phlorizin-sensitive SGLT transporters and NHE3 interact functionally in the proximal tubule. PMID:24652792
Pessoa, Thaissa Dantas; Campos, Luciene Cristina Gastalho; Carraro-Lacroix, Luciene; Girardi, Adriana C C; Malnic, Gerhard
A proximity fuze system includes an optical ranging apparatus, a detonation circuit controlled by the optical ranging apparatus, and an explosive charge detonated by the detonation circuit. The optical ranging apparatus includes a pulsed laser light source for generating target ranging light pulses and optical reference light pulses. A single lens directs ranging pulses to a target and collects reflected light from the target. An optical fiber bundle is used for delaying the optical reference pulses to correspond to a predetermined distance from the target. The optical ranging apparatus includes circuitry for providing a first signal depending upon the light pulses reflected from the target, a second signal depending upon the light pulses from the optical delay fiber bundle, and an output signal when the first and second signals coincide with each other. The output signal occurs when the distance from the target is equal to the predetermined distance from the target. Additional circuitry distinguishes pulses reflected from the target from background solar radiation. 3 figs.
Harrison, T.R.
A proximity fuze system includes an optical ranging apparatus, a detonation circuit controlled by the optical ranging apparatus, and an explosive charge detonated by the detonation cirtcuit. The optical ranging apparatus includes a pulsed laser light source for generating target ranging light pulses and optical reference light pulses. A single lens directs ranging pulses to a target and collects reflected light from the target. An optical fiber bundle is used for delaying the optical reference pulses to correspond to a predetermined distance from the target. The optical ranging apparatus includes circuitry for providing a first signal depending upon the light pulses reflected from the target, a second signal depending upon the light pulses from the optical delay fiber bundle, and an output signal when the first and second signals coincide with each other. The output signal occurs when the distance from the target is equal to the predetermined distance form the target. Additional circuitry distinguishes pulses reflected from the target from background solar radiation.
Harrison, Thomas R. (Stockton, CA)
The molecular mechanisms involved in the Ang-(1¢7) [angiotensin-(1¢7)] effect on sodium renal excretion remain to be determined. In a previous study, we showed that Ang-(1¢7) has a biphasic effect on the proximal tubule Na+-ATPase activity, with the stimulatory effect mediated by the AT1 receptor. In the present study, we investigated the molecular mechanisms involved in the inhibition of the Na+-ATPase by Ang-(1¢7). All experiments were carried out in the presence of 0.1ĀnM losartan to block the AT1 receptor-mediated stimulation. In this condition, Ang-(1¢7) at 0.1ĀnM inhibited the Na+-ATPase activity of the proximal tubule by 54%. This effect was reversed by 10ĀnM PD123319, a specific antagonist of the AT2 receptor, and by 1Ā?M GDP[?-S] (guanosine 5?-[?-thio]diphosphate), an inhibitor of G protein. Ang-(1¢7) at 0.1ĀM induced [35S]GTP[S] (guanosine 5?-[?-[35S]thio]triphosphate) binding and 1Ā?g/ml pertussis toxin, an inhibitor of Gi/o protein, reversed the Ang-(1¢7) effect. Furthermore, it was observed that the inhibitory effect of Ang-(1¢7) on the Na+-ATPase activity was completely reversed by 0.1Ā?M LY83583, an inhibitor of guanylate cyclase, and by 2Ā?M KT5823, a PKG (protein kinase G) inhibitor, and was mimicked by 10ĀnM d-cGMP (dibutyryl cGMP). Ang-(1¢7) increased the PKG activity by 152% and this effect was abolished by 10ĀnM PD123319 and 0.1Ā?M LY83583. Taken together, these data indicate that Ang-(1¢7) inhibits the proximal tubule Na+-ATPase by interaction with the AT2 receptor that subsequently activates the Gi/o protein/cGMP/PKG pathway. PMID:16390332
Lara, LucienneĀdaĀSilva; Cavalcante, FabĒola; Axelband, Flavia; De Souza, AloaĀMachado; Lopes, AnibalĀGil; Caruso-Neves, Celso
MOBILE PROXIMITY PAYMENT: ECOSYSTEM AND OVERVIEW OF NFC TECHNOLOGY 1. Introduction Handsets confirm topic in the mobile payment field and promises a revolution in the world of payments. This article traces the state-of-the-art in mobile proximity payment field and traces the most probable evolution
Shamos, Michael I.
Neurogenic regulation of proximal bicarbonate and chloride reabsorption.
Although a change in renal nerve activity is known to alter proximal reabsorption, it is unclear whether reabsorption of NaHCO3 or NaCl or both are affected. Sprague-Dawley rats (n = 10) were studied using free-flow micropuncture techniques during euvolemia and following acute ipsilateral denervation. Glomerular filtration rate and single nephron glomerular filtration rate were stable. Absolute proximal bicarbonate reabsorption fell following denervation (933 +/- 40 to 817 +/- 30 pmol/min) with a parallel reduction in chloride reabsorption (1,643 +/- 116 to 1,341 +/- 129 peq/min). Urinary sodium, potassium, bicarbonate, and chloride excretion all increased significantly. To further assess the physiological significance of neurogenic modulation of proximal transport, other rats (n = 6) were subjected to acute unilateral nephrectomy (AUN). There is evidence that AUN induces a contralateral natriuresis (renorenal reflex) at least partially by causing inhibition of efferent renal nerve traffic. AUN caused significant changes in proximal NaHCO3 and NaCl reabsorption as well as in whole kidney electrolyte excretion in the same pattern as had denervation. Prior denervation of the remaining kidney prevented the proximal and whole kidney response to AUN (n = 6). In conclusion, depression of renal nerve activity inhibits both NaHCO3 and NaCl reabsorption in the rat superficial proximal convoluted tubule. The data are consistent with the hypothesis that changes in renal nerve activity modify whole kidney electrolyte excretion under physiological conditions at least partially by regulating proximal transport. PMID:3942224
Cogan, M G
Proximal tubule function and response to acidosis.
The human kidneys produce approximately 160-170 L of ultrafiltrate per day. The proximal tubule contributes to fluid, electrolyte, and nutrient homeostasis by reabsorbing approximately 60%-70% of the water and NaCl, a greater proportion of the NaHCO3, and nearly all of the nutrients in the ultrafiltrate. The proximal tubule is also the site of active solute secretion, hormone production, and many of the metabolic functions of the kidney. This review discusses the transport of NaCl, NaHCO3, glucose, amino acids, and two clinically important anions, citrate and phosphate. NaCl and the accompanying water are reabsorbed in an isotonic fashion. The energy that drives this process is generated largely by the basolateral Na(+)/K(+)-ATPase, which creates an inward negative membrane potential and Na(+)-gradient. Various Na(+)-dependent countertransporters and cotransporters use the energy of this gradient to promote the uptake of HCO3 (-) and various solutes, respectively. A Na(+)-dependent cotransporter mediates the movement of HCO3 (-) across the basolateral membrane, whereas various Na(+)-independent passive transporters accomplish the export of various other solutes. To illustrate its homeostatic feat, the proximal tubule alters its metabolism and transport properties in response to metabolic acidosis. The uptake and catabolism of glutamine and citrate are increased during acidosis, whereas the recovery of phosphate from the ultrafiltrate is decreased. The increased catabolism of glutamine results in increased ammoniagenesis and gluconeogenesis. Excretion of the resulting ammonium ions facilitates the excretion of acid, whereas the combined pathways accomplish the net production of HCO3 (-) ions that are added to the plasma to partially restore acid-base balance. PMID:23908456
Curthoys, Norman P; Moe, Orson W
Proximal Tubule Function and Response to Acidosis
Summary The human kidneys produce approximately 160¢170 L of ultrafiltrate per day. The proximal tubule contributes to fluid, electrolyte, and nutrient homeostasis by reabsorbing approximately 60%¢70% of the water and NaCl, a greater proportion of the NaHCO3, and nearly all of the nutrients in the ultrafiltrate. The proximal tubule is also the site of active solute secretion, hormone production, and many of the metabolic functions of the kidney. This review discusses the transport of NaCl, NaHCO3, glucose, amino acids, and two clinically important anions, citrate and phosphate. NaCl and the accompanying water are reabsorbed in an isotonic fashion. The energy that drives this process is generated largely by the basolateral Na+/K+-ATPase, which creates an inward negative membrane potential and Na+-gradient. Various Na+-dependent countertransporters and cotransporters use the energy of this gradient to promote the uptake of HCO3? and various solutes, respectively. A Na+-dependent cotransporter mediates the movement of HCO3? across the basolateral membrane, whereas various Na+-independent passive transporters accomplish the export of various other solutes. To illustrate its homeostatic feat, the proximal tubule alters its metabolism and transport properties in response to metabolic acidosis. The uptake and catabolism of glutamine and citrate are increased during acidosis, whereas the recovery of phosphate from the ultrafiltrate is decreased. The increased catabolism of glutamine results in increased ammoniagenesis and gluconeogenesis. Excretion of the resulting ammonium ions facilitates the excretion of acid, whereas the combined pathways accomplish the net production of HCO3? ions that are added to the plasma to partially restore acid-base balance. PMID:23908456
Two-Dimensional Optical Proximity Effects
NASA Astrophysics Data System (ADS)
In projection printing the proximity effects between adjacent two-dimensional features such as concentric elbows can be the limiting factor in designing layout rules. An aerial image simulation code based on the imaging algorithms in SAMPLE has been developed and used to investigate these proximity effects. The program accepts arbitrary polygonal shapes constructed of rectangular and triangular patches. The image is calculated using Hopkins transmission cross coefficient formulation and uses rapid integral evaluation techniques. The cpu time for this FORTRAN F77 program depends on the size of the mask and the partial coherence factor as 0.25[(1 + ?) 2A(NA/?)2]2 seconds on a DEC VAX 11/780 using double precision, where A is the mask area, ? the coherence factor, NA the numerical aperture and ? the wavelength. The output intensity can be displayed with graphics tools such as UNIGRAFIX or cross-sectioned for input to SAMPLE development simulation along critical paths. Proximity effects in critical regions between features such as nested elbows, contacts near contacts and lines, and lines near large pads are studied. For small contacts studies show that a contact hole can be placed as close as 0.5?/NA microns to another contact hole. For nested elbows the critical effect is the variation in intensity in the straight regions just adjacent to the corner. This undesirable variation is primarily due to the intrafeature intensity interactions and is not greatly influenced by the proximity of another nested elbow. For general feature shapes the proximity effects are reduced by increasing the partial coherence factor to 0.5 or higher but at the cost of reducing contrast and peak intensity. For contact masks a partial coherence of 0.3 is recommended for higher edge slope and peak intensities. Proximity effects of small defects are also illustrated.
Flanner, Philip D.; Subramanian, Shankar; Neureuther, Andrew R.
Influence of ammonia on sodium absorption in rat proximal colon
The influence of ammonia on sodium and chloride fluxes in rat proximal colon was studied in Ussing chamber experiments. Under short-circuit conditions, the proximal colon absorbed sodium and secreted chloride. The presence of ammonia (30 mmol l-1 mucosal) diminished Na+ absorption, but had hardly any influence on Cl- fluxes. Blocking the apical Na+\\/H+ exchanger isoform NHE2 by amiloride or HOE642
Rainer Cermak; Claudia Lawnitzak; Erwin Scharrer
A proximity sensor based on a closed field circuit is disclosed. The circuit comprises a ring oscillator using a symmetrical array of plates that creates an oscillating displacement current. The displacement current varies as a function of the proximity of objects to the plate array. Preferably the plates are in the form of a group of three pair of symmetric plates having a common center, arranged in a hexagonal pattern with opposing plates linked as a pair. The sensor produces logic level pulses suitable for interfacing with a computer or process controller. The proximity sensor can be incorporated into a load cell, a differential pressure gauge, or a device for measuring the consistency of a characteristic of a material where a variation in the consistency causes the dielectric constant of the material to change. 14 figs.
Kronberg, J.W.
A proximity sensor based on a closed field circuit. The circuit comprises a ring oscillator using a symmetrical array of plates that creates an oscillating displacement current. The displacement current varies as a function of the proximity of objects to the plate array. Preferably the plates are in the form of a group of three pair of symmetric plates having a common center, arranged in a hexagonal pattern with opposing plates linked as a pair. The sensor produces logic level pulses suitable for interfacing with a computer or process controller. The proximity sensor can be incorporated into a load cell, a differential pressure gauge, or a device for measuring the consistency of a characteristic of a material where a variation in the consistency causes the dielectric constant of the material to change.
Kronberg, James W. (Aiken, SC)
... that arm. But sometimes an injury or small tear in the tendon can cause problems right away. Some of the ... do surgery to repair badly injured proximal biceps tendons, it's usually for adults. Kids and teens ... can include the following: Rest your arm. Stop ...
The purpose of our study was to biomechanically compare, under cyclic loading conditions, fracture site motion, humeral head collapse, and intra-articular hardware penetration in simulated 3-part osteoporotic proximal humeral fractures stabilized with 1 of 2 locking-plate constructs. We performed fixation on simulated 3-part proximal humeral fractures in 10 pairs of cadaveric osteoporotic humeri with a Hand Innovations S3 Proximal Humerus Plate (S3 plate) or an LCP Proximal Humerus Plate (LCP plate; 1 each for each pair). The specimens were potted, mounted on a materials testing machine, and subjected to 5000 cycles of abduction in the scapular plane, loading through the supraspinatus tendon. Interfragmentary displacement at 2 virtual points (the most medial aspect of the calcar and the most superior aspect of the osteotomy line between the greater tuberosity and humeral head) was measured using an optical tracking system. Humeral head rotation was also measured. We used a generalized linear latent and mixed model to check for an effect of cyclic loading and treatment on the parameters of interest (significance, P < .05). After cyclic loading, the S3 plate humeri showed significantly greater displacement of the greater tuberosity fragment and rotation of the humeral head and a trend (not a significant difference) toward greater displacement at the calcar. No hardware penetration was noted for either repair. Although the S3 plate repairs resulted in significantly more fracture site motion, it is unknown whether the magnitude of the motion is clinically significant. PMID:23569665
Rose, David M.; Sutter, Edward G.; Mears, Simon C.; Gupta, Rohit R.; Belkoff, Stephen M.
Despite more than 3,000 articles published proximal humeral fractures remain diffi cult to defi ne and classify, natural evolution\\u000a has been poorly defi ned and the best treatment option is yet to be established. Current trends in management of these complex\\u000a fractures are analyzed and rationale decision-making is presented.
C. Torrens
ERIC Educational Resources Information Center
This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter,ģ
Donahue, Craig J.; Rais, Elizabeth A.
ERIC Educational Resources Information Center
Discussion of models that have been developed to structure text documents for information retrieval focuses on XML and its proposed query language XQL. Considers efficiency of the query engine and shows that an already existing model, Proximal Nodes, can be used as an efficient query engine behind an XQL front-end. (Author/LRW)
Baeza-Yates, Ricardo; Navarro, Gonzalo
Subacute diabetic proximal neuropathy
NASA Technical Reports Server (NTRS)
OBJECTIVE: To evaluate the clinical, electrophysiologic, autonomic, and neuropathologic characteristics and the natural history of subacute diabetic proximal neuropathy and its response to immunotherapy. MATERIAL AND METHODS: For the 12-year period from 1983 to 1995, we conducted a retrospective review of medical records of Mayo Clinic patients with diabetes who had subacute onset and progression of proximal weakness. The responses of treated versus untreated patients were compared statistically. RESULTS: During the designated study period, 44 patients with subacute diabetic proximal neuropathy were encountered. Most patients were middle-aged or elderly, and no sex preponderance was noted. The proximal muscle weakness often was associated with reduced or absent lower extremity reflexes. Associated weight loss was a common finding. Frequently, patients had some evidence of demyelination on nerve conduction studies, but it invariably was accompanied by concomitant axonal degeneration. The cerebrospinal fluid protein concentration was usually increased. Diffuse and substantial autonomic failure was generally present. In most cases, a sural nerve biopsy specimen suggested demyelination, although evidence of an inflammatory infiltrate was less common. Of 12 patients who received treatment (with prednisone, intravenous immune globulin, or plasma exchange), 9 had improvement of their conditions, but 17 of 29 untreated patients (59%) with follow-up also eventually had improvement, albeit at a much slower rate. Improvement was usually incomplete. CONCLUSION: We suggest that the entity of subacute diabetic proximal neuropathy is an extensive and severe variant of bilateral lumbosacral radiculoplexopathy, with some features suggestive of an immune-mediated cause. It differs from chronic inflammatory demyelinating polyradiculoneuropathy in that most cases have a more restricted distribution and seem to be monophasic and self-limiting. The efficacy of immunotherapy is unproved, but such intervention may be considered in the severe and progressive cases or ones associated with severe neuropathic pain.
Pascoe, M. K.; Low, P. A.; Windebank, A. J.; Litchy, W. J.
Proximal Point Methods Revisited
NASA Astrophysics Data System (ADS)
The proximal point methods have been widely used in the last decades to approximate the solutions of nonlinear equations associated with monotone operators. Inspired by the iterative procedure defined by B. Martinet (1970), R.T. Rockafellar introduced in 1976 the so-called proximal point algorithm (PPA) for a general maximal monotone operator. The sequence generated by this iterative method is weakly convergent under appropriate conditions, but not necessarily strongly convergent, as proved by O. G³ler (1991). This fact explains the introduction of different modified versions of the PPA which generate strongly convergent sequences under appropriate conditions, including the contraction-PPA defined by H.K. Xu in 2002. Here we discuss Xu's modified PPA as well as some of its generalizations. Special attention is paid to the computational errors, in particular the original Rockafellar summability assumption is replaced by the condition that the error sequence converges to zero strongly.
Boikanyo, Oganeditse A.; Moro?anu, Gheorghe
Proximity Networks and Epidemics
NASA Astrophysics Data System (ADS)
We presented the basis of a framework to account for the dynamics of contacts in epidemic processes, through the notion of dynamic proximity graphs. By varying the integration time-parameter T, which is the period of infectivity one can give a simple account for some of the differences in the observed contact networks for different diseases, such as smallpox, or AIDS. Our simplistic model also seems to shed some light on the shape of the degree distribution of the measured people-people contact network from the EPISIM data. We certainly do not claim that the simplistic graph integration model above is a good model for dynamic contact graphs. It only contains the essential ingredients for such processes to produce a qualitative agreement with some observations. We expect that further refinements and extensions to this picture, in particular deriving the link-probabilities in the dynamic proximity graph from more realistic contact dynamics should improve the agreement between models and data.
Guclu, Hasan; Toroczkai, Zoltßn
This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter, fixed carbon, and ash content are determined for each sample and comparisons are made. Proximate analysis is performed on a coal sample from a local electric utility. From the weight percent sulfur found in the coal (determined by a separate procedure the Eschka method) and the ash content, students calculate the quantity of sulfur dioxide emissions and ash produced annually by a large coal-fired electric power plant.
Donahue, C.J.; Rais, E.A. [University of Michigan, Dearborn, MI (USA)
Distributed proximity sensor system
NASA Technical Reports Server (NTRS)
The invention relates to sensors embedded on the surface of a robot hand, or other moving member. By distributing proximity sensors capable of detecting distances and angles to points on the surface of an object, information is obtained for achieving noncontacting shape and distance perception, i.e., for automatic determination of the object's shape, direction, and distance, as well as the orientation of the object relative to the robot hand or other moving member.
Lee, Sukhan (inventor)
Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal Point Methods Yves Lucet & Warren Hare July 24, 2013 1 / 26 #12;Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Outline 1
Proximity Relationships in Rhodopsin
Energy transfer was used as a spectroscopic ruler to deduce proximity relationships within bovine rhodopsin in digitonin solution. Rhodopsin was specifically labeled with fluorescent chromophores at three sites. Site A was alkylated by fluorescent derivatives of iodoacetamide. Site B was labeled by fluorescent disulfides, by a disulfide-sulfhydryl interchange reaction. Sites A and B are sulfhydryl residues. Acridine derivatives were tightly bound to site C by noncovalent interactions. The labeled rhodopsins retained their 500-nm absorption band and were regenerable after bleaching, suggesting that the fluorescent probes did not grossly perturb the conformation of the protein. A fluorescent chromophore at one of these sites served as the energy donor, while 11-cis retinal was the energy acceptor. The efficiency of singlet-singlet energy transfer was determined from the quantum yield and excited-state lifetime of the donor in the presence and absence of the acceptor. By F÷rster's theory, the apparent distances between 11-cis retinal and sites A, B, and C were calculated to be 75,55, and 48 ┼, respectively. Energy transfer measurements on rhodopsin labeled at two of these sites gave these apparent distances: 35 ┼ for A to B, 32 ┼ for A to C, and 30 ┼ for B to C. These energy transfer studies suggest that the rhodopsin molecule has a length of at least 75 ┼. Thus, the rhodopsin molecule appears to be sufficiently long to traverse the disc membrane. Rhodopsin might act as a light-controlled gate. PMID:4504322
Wu, Cheng-Wen; Stryer, Lubert
Mechanisms of inhibition of proximal acidification by PTH.
The parathyroid hormone (PTH) effects on luminal Na-H exchange and basolateral Na-HCO3 cotransport were examined in isolated perfused rabbit proximal convoluted tubules. Lumen pH (pHi) and cell pH (pHi) were measured by a fluorescent technique using 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). The time course of the PTH effect on proximal acidification was first determined by continuous monitoring of pHi in a stop-flow condition. PTH 10(-8) M added to the bath promptly inhibited the acid pHl generation. Adenosine 3',5'-cyclic monophosphate (cAMP) (10(-4) M) added to the bath mimicked the PTH effect. Luminal Na-H exchange was assayed by monitoring changes in pHi (dpHi/dt) in response to luminal Na+ removal in HCO3- free condition. The addition of PTH or cAMP for 5 min decreased dpHi/dt by 30 and 37%, respectively. Basolateral Na-HCO3 cotransport was assayed by measuring dpHi/dt caused by bath Na+ removal. The addition of PTH or cAMP for 5 min did not change the dpHi/dt. PTH also did not alter the dpHi/dt induced by reducing the bath HCO3- from 25 to 5 mM. The addition of PTH or cAMP to the bath slightly reduced pHi by 0.05. These results suggest that 1) PTH inhibits proximal acidification very rapidly and the effect reached a maximum within 10 min, 2) PTH rapidly inhibits luminal Na-H exchange but not basolateral Na-HCO3 cotransport in a short period, and 3) this effect is at least partly mediated by cAMP-dependent mechanisms. PMID:1647688
Sasaki, S; Marumo, F
Pathophysiology and management of proximal tubal blockage
Objective: To review the physiology, pathology, and treatment of proximal tubal disease.Data Identification: Relevant reports on the pathophysiology of proximal tubal disease were reviewed. All studies in English of microsurgery and macrosurgery, and of radiographic and hysteroscopic cannulation in women with proximal tubal blockage were identified through MEDLINE searches.Study Selection: All studies of therapy for proximal blockage that included pregnancy
Gerard M Honorķ; Alan E. C Holden; Robert S Schenken
The multi-PDZ domain containing protein Na(+)/H(+) Exchanger Regulatory Factor 1 (NHERF1) binds to Na(+)/H(+) exchanger 3 (NHE3) and is associated with the brush border (BB) membrane of murine kidney and small intestine. Although studies in BB isolated from kidney cortex of wild type and NHERF1(-/-) mice have shown that NHERF1 is necessary for cAMP inhibition of NHE3 activity, a role of NHERF1 in NHE3 regulation in small intestine and in intact kidney has not been established. Here a method using multi-photon microscopy with the pH-sensitive dye SNARF-4F (carboxyseminaphthorhodafluors-4F) to measure BB NHE3 activity in intact murine tissue and use it to examine the role of NHERF1 in regulation of NHE3 activity. NHE3 activity in wild type and NHERF1(-/-) ileum and wild type kidney cortex were inhibited by cAMP, whereas the cAMP effect was abolished in kidney cortex of NHERF1(-/-) mice. cAMP inhibition of NHE3 activity in these two tissues is mediated by different mechanisms. In ileum, a protein kinase A (PKA)-dependent mechanism accounts for all cAMP inhibition of NHE3 activity since the PKA antagonist H-89 abolished the inhibitory effect of cAMP. In kidney, both PKA-dependent and non-PKA-dependent mechanisms were involved, with the latter reproduced by the effect on an EPAC (exchange protein directly activated by cAMP) agonist (8-(4-chlorophenylthio)-2'O-Me-cAMP). In contrast, the EPAC agonist had no effect in proximal tubules in NHERF1(-/-) mice. These data suggest that in proximal tubule, NHERF1 is required for all cAMP inhibition of NHE3, which occurs through both EPAC-dependent and PKA-dependent mechanisms; in contrast, cAMP inhibits ileal NHE3 only by a PKA-dependent pathway, which is independent of NHERF1 and EPAC. PMID:17580307
Murtazina, Rakhilya; Kovbasnjuk, Olga; Zachos, Nicholas C; Li, Xuhang; Chen, Yueping; Hubbard, Ann; Hogema, Boris M; Steplock, Deborah; Seidler, Ursula; Hoque, Kazi M; Tse, Chung Ming; De Jonge, Hugo R; Weinman, Edward J; Donowitz, M
Measuring Proximity between Heterogeneous Data
Measuring proximity (or similarity) underlies many algorithms in information processing (by humans or indeed animals, or by machines). When the data involved are heterogeneous this issue is further complicated. This paper discusses some of the difficulties of measuring similarity between heterogeneous data and possible directions for addressing these difficulties using computational intelligence\\/fuzzy set based techniques. An important concept underlying the
Anca Ralescu; Michihiko Minoh
Intracellular pH in snake renal proximal tubules.
Intracellular pH (pHi) was studied in isolated proximal renal tubules of garter snakes (Thamnophis spp.) with oil-filled lumens under control conditions [N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)-buffered medium with pH 7.4 at 25 degrees C] and in response to NH4Cl pulse. pHi was measured with the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). Control resting pHi (7.1) and acidification in response to NH4Cl pulse (minimum pHi, 6.6) were essentially the same in snake tubules with oil-filled lumens or perfused lumens and in rabbit S2 proximal tubules with oil-filled lumens. Rate of recovery of pHi (dpHi/dt) from acid to resting level in snake tubules (2.5 x 10(-3) pH U/s was about one-third of that in rabbit tubules. Resting pHi and dpHi/dt from acid to resting level were Na+ dependent in the distal portion but not the proximal portion of snake proximal tubules. However, dpHi/dt was not influenced by amiloride or 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid in snake proximal tubules, suggesting that the effect of Na+ on dpHi/dt and resting pHi may involve membrane potential. This study also indicates that oil-filled lumens do not interfere with measurements of resting pHi and do permit evaluation of pHi regulation at the basolateral membrane without complications from transport at the luminal membrane. PMID:7485599
Kim, Y K; Dantzler, W H
Electromagnetic properties of proximity systems
Magnetic screening in the proximity system S/sub ..cap alpha../-M/sub ..beta../, where M/sub ..beta../ is a normal metal N, semiconductor (semimetal), or a superconductor, is studied. Main attention is paid to the low-temperature region where nonlocality plays an important role. The thermodynamic Green's-function method is employed in order to describe the behavior of the proximity system in an external field. The temperature and thickness dependences of the penetration depth lambda are obtained. The dependence lambda(T) differs in a striking way from the dependence in usual superconductors. The strong-coupling effect is taken into account. A special case of screening in a superconducting film backed by a size-quantizing semimetal film is considered. The results obtained are in good agreement with experimental data.
Kresin, V.Z.
Proximity operations in space station environment
Viewgraphs on proximity operations in space station environment are presented. Topics covered include: automated flight; remote manual piloting; task requirements and constraints; problem formulation; and flight parameter flow\\/pilot interaction for proximity operations task.
Brandt Rhodes
Fractures of the proximal humerus.
Fractures of the proximal humerus have been diagnosed and managed since the earliest known surgical texts. For more than four millennia the preferred treatment was forceful traction, closed reduction, and immobilization with linen soaked in combinations of oil, honey, alum, wine, or cerate. The bandages were further supported by splints made of wood or coarse grass. Healing was expected in forty days. Different fracture patterns have been discussed and classified since Ancient Greece. Current classification of proximal humeral fractures mainly relies on the classifications proposed by Charles Neer and the AO/OTA classification. Since the late 1980's it has been known that intra- and inter-observer variation was high within the two systems. I conducted a series of observer studies to qualify the disagreement further and to study to what extent improvement of agreement could be obtained. No clinically significant differences in observer agreement were found at different levels of clinical experience, by reducing the number of categories, or by adding high quality radiographs, CT or 3D CT scans. A consistently low agreement on the Neer classification within and between untrained orthopaedic doctors was found. However, we also found that inter-observer agreement on treatment recommendation was higher than the agreement on the Neer classification. In a randomized trial we found that agreement could improve significantly by training of doctors, especially among specialists. However, classification of proximal humeral fractures remains a challenge for the conduct, reporting, and interpretation of clinical trials. The evidence for the benefits of surgery in complex fractures of the proximal humerus is weak. In three systematic reviews I studied the outcome after locking plate osteosynthesis or reverse arthroplasty in complex fractures patterns. No randomized trials or well-conducted comparative studies were identified. High failure rates suggest that the use of these implants for complex fractures of the humerus should not be used outside clinical protocols. I recommend the conduct of randomized trials, and a design of such study is proposed. PMID:24303817
Brorson, Stig
New Advances in the Study of the Proximal Point Algorithm
NASA Astrophysics Data System (ADS)
Consider in a real Hilbert space H the inexact, Halpern-type, proximal point algorithm xn+1 = ?nu+(1-?n)J?nxn+en, n = 0,1,ģ, (HŚPPA) where u, x?H are given points, J?n = (I+?na) for a given maximal monotone operator A, and (en) is the error sequence, under new assumptions on ?n?(0,1) and ?n?(0,1). Several strong convergence results for the HŚPPA are presented under the general condition that the error sequence converges strongly to zero, thus improving the classical Rockafellar's summability condition on (?en?) that has been extensively used so far for different versions of the proximal point algorithm. Our results extend and improve some recent ones. These results can be applied to approximate minimizers of convex functionals. Convergence rate estimates are established for a sequence approximating the minimum value of such a functional.
Moro?anu, Gheorghe
Half-tone proximity lithography
NASA Astrophysics Data System (ADS)
The half-tone lithography using pixilated chromium masks in a projection stepper is an established technology in micro-optics fabrication. However, the projection lithography tool is comparably expensive and the achievable lateral resolution is typically limited. By using pixel diffraction effects, binary and continuous profile lithography with submicron resolution can be installed on a conventional mask aligner. To achieve this goal the control of both, the angular spectrum of the illumination and the mask features is essential. We used a novel micro-optics based illumination system referred as "MO Exposure Optics System" in a SUSS MicroTec MA6 mask aligner for the dedicated shaping of the angular illumination distribution. In combination with an adapted lithography mask the formation of a desired intensity distribution in the resist layer is possible. A general mathematic model describes the relation between the angular spectrum of the mask illumination, pixel size and pitch in the mask, proximity distance and propagated field, which also includes special cases like Talbot imaging. We show that a wide range of different micro-optical structures can be optimized by controlling the light diffraction in proximity lithography. Parameter settings were found for submicron binary pattern up to continuous profile structures with extensions up to several tens of microns. An additional interesting application of this approach is the combination of binary and continuous profiles in single elements, e.g. micro lenses with diffractive correction or AR structures. Experimental results achieved for blazed gratings with a period of 2 microns are presented.
Harzendorf, Torsten; Stuerzebecher, Lorenz; Vogler, Uwe; Zeitner, Uwe D.; Voelkel, Reinhard
Idiopathic Proximal Hemimegacolon in an Adult Woman
Idiopathic proximal hemimegacolon is a disorder characterized by bowel dilatation proximal to the splenic flexure. It is a very rare and therefore a poorly understood clinical entity. This report describes a case of idiopathic proximal hemimegacolon in a 44-year-old woman. The patient suffered from 2 episodes of constipation and bowel dilatation over 4 years and was successfully treated by medical therapy. PMID:20535353
Noh, Jung Won; Son, Seo Young; Ok, Chang Soo; Lee, Gayeon; Min, Byung-Hoon
Proximate sources of collective teacher efficacy
Purpose ¢ Recent scholarship has augmented Bandura's theory underlying efficacy formation by pointing to more proximate sources of efficacy information involved in forming collective teacher efficacy. These proximate sources of efficacy information theoretically shape a teacher's perception of the teaching context, operationalizing the difficulty of the teaching task that faces the school and the faculty's collective competence to be successful
Curt M. Adams; Patrick B. Forsyth
Proximal Participation: A Pathway into Work
ERIC Educational Resources Information Center
In a longitudinal case study of apprentices, the term proximal participation was coined to describe the entry process of young people, with unclear career destinations, into the trade of baking. This article unravels the significance of proximal participation in the decision-making processes of young people who enter a trade through initialģ
Chan, Selena
The relationship between renal metabolism and proximal tubule transport during ontogeny
The proximal tubules of newborn and adult animals reabsorb a similar fraction of the filtered load of Na+ and H2O (65%¢70%). In tubules from adult animals, transcellular, active Na+ reabsorption accounts for one-third of the total, while two-thirds occur passively through the paracellular pathway, driven by hydrostatic and oncotic forces (one-third) and by cell-generated effective osmotic and ionic gradients (one-third).
Mario Barac-Nieto; Adrian Spitzer
The mechanism of bicarbonate transport across the peritubular cell membrane was investigated in rat kidney proximal tubules in situ by measuring cell pH and cell Na+ activity in response to sudden reduction of peritubular Na+ and\\/or HCO3-. The following observations were made: 1. sudden peritubular reduction of either ion concentration produced the same transient depolarizing potential response; 2. bicarbonate efflux
K. Yoshitomi; B.-Ch. Burckhardt; E. Fr÷mter
Proximal Priority Laser Therapy: PPLT
NASA Astrophysics Data System (ADS)
The author has, in the past, classified treatment methods for pain geometrically as point, line, two-dimensional, three-dimensional treatment and has used these over the years. However as a practitioner of western medicine, the author originally treated pain only directed at the painful site, and encountered cases where local treatment did not suffice. The author proved with SPECT and the Rand Phantom that treating the neck which is the midpoint of the brain, the center of the nervous system and the heart, the center of circulation, increased cerebral blood flow and also that laser emitted to neck will reach the spinal chord no matter from where on the neck the laser is emitted. From such research and 25 years of clinical experience, the author has created an anatomy based, systemic treatment method called the Proximal Priority Laser Therapy (PPLT) where not only the cerebral cortex, spinal chord and peripheral nerves are treated but also the tracts of blood vessels and lymph ducts are treated as well. Treatment method and cases are presented herein.
Ohshiro, Toshio
Range gated strip proximity sensor
A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance.
McEwan, Thomas E. (Livermore, CA)
Context-Aware Group Services in Proximity-Based Mobile Social Networks
Groups exist in mobile users' social interactions Groups can be used for apps based on informationContext-Aware Group Services in Proximity-Based Mobile Social Networks Na Yu and Dr. Qi Han (http contexts into contacts to generate user mobility profiles with PoI visits and contacts; - Construct
Na+ recirculation and isosmotic transport.
The Na(+) recirculation theory for solute-coupled fluid absorption is an expansion of the local osmosis concept introduced by Curran and analyzed by Diamond & Bossert. Based on studies on small intestine the theory assumes that the observed recirculation of Na(+) serves regulation of the osmolarity of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal NaCl by sucrose as well as the linear dependence of volume absorption on luminal NaCl concentration. Analysis of solvent drag on Na(+) in tight junctions provides explanation for the surprisingly high metabolic efficiency of Na(+) reabsorption. The model predicts and explains low metabolic efficiency in diluted external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and < or = 1 mOsm in proximal tubule. Truly isosmotic transport demands a Na(+) recirculation of 50-70% in small intestine but might be barely measurable in proximal tubule. The model fails to reproduce a certain type of observations: The reduced volume absorption at transepithelial osmotic equilibrium in AQP1 knockout mice, and the stimulated water absorption by gallbladder in diluted external solutions. Thus, it indicates cellular regulation of apical Na(+) uptake, which is not included in the mathematical treatment. PMID:17206513
Larsen, E H; M°bjerg, N
This initiated the development of the so-called proximal gradient or forward- ...... Contour plot (left) and energy landscape (right) of the nonconvex function h shown ...... rithm for maximal monotone operators in Hilbert space, SIAM Journal onĀ...
Performance Characterization of Random Proximity Sensor Networks
Performance Characterization of Random Proximity Sensor Networks Agostino Capponi Department-- In this paper, we characterize the localization per- formance and connectivity of sensors networks consisting connected active nodes. I. INTRODUCTION The emerging world of sensor networks has imposed a different
Jensen, Grant J.
Promoting proximal formative assessment with relational discourse
NSDL National Science Digital Library
The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.
Scherr, Rachel E.; Close, Hunter G.; Mckagan, Sarah B.
Reactive Grasping Using Optical Proximity Sensors
We propose a system for improving grasping using fingertip optical proximity sensors that allows us to perform online grasp adjustments to an initial grasp point without requiring premature object contact or regrasping ...
Nangeroni, Paul
Promoting proximal formative assessment with relational discourse
NASA Astrophysics Data System (ADS)
The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.
Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.
Control of spacecraft in proximity orbits
Formation flying of spacecraft and autonomous rendezvous and docking of spacecraft are two missions in which satellites operate in close proximity and their relative trajectories are critically important. Both classes of ...
Breger, Louis Scott, 1979-
Opportunistic, collaborative and synchronized, proximal device ecology
CoSync is an on-device software framework for coordinating proximal consumer electronic devices in order to create a synchronized, opportunistic and collaborative device ecology. The CoSync device ecology combines multiple ...
Toledano, Eyal
Proximal biceps tendon: injuries and management.
The long head of the biceps tendon is a known pain generator of the shoulder. There are numerous pathologic entities that may affect this tendon, including tendonitis, partial tearing, and subluxation. These conditions are often associated with rotator cuff tears, especially those involving the subscapularis. Operative interventions include tenotomy and tenodesis. Tenodesis can be preformed in a proximal or distal location. Subpectoral tenodesis may have a lower recurrence rate than proximal-based techniques. PMID:18703976
Friedman, Darren J; Dunn, John C; Higgins, Laurence D; Warner, Jon J P
On the mechanism of bicarbonate exit from renal proximal tubular cells.
We compare here the results of electrophysiological measurements on proximal tubular cells performed on rat kidney in vivo and on isolated rabbit and rat tubules in vitro. Based on different effects of carbonic anhydrase inhibitors in the in vivo and in vitro preparation, we conclude that NaHCO3 cotransport across the basolateral cell membrane functions as Na(+)-CO3(2-)-HCO3- cotransport in vivo, but as Na(+)-HCO3(-)-HCO3- cotransport in the classical in vitro preparation. The former, but not the latter, transport mode is characterized by generation of local disequilibrium pH/CO3(2-) concentrations that oppose fluxes if membrane-bound carbonic anhydrase is inhibited. In support of this conclusion, we find that overall transport functions with a HCO3- to Na+ stoichiometry of 3:1 in vivo (since each transported CO3(2-) eventually generates 2 HCO3- ions), but 2:1 in vitro. This has been deduced from various measurements, among them super-Nernstian and reverse nernstian, potential responses to changing ion concentrations which are characteristic of obligatorily coupled cation-anion cotransporters, but are not known in classical electrochemistry. The different transport modes in vivo and in vitro suggest that isolated proximal tubules have functional deficits compared to proximal tubules in vivo. PMID:8743474
Seki, G; Coppola, S; Yoshitomi, K; Burckhardt, B C; Samarzija, I; M³ller-Berger, S; Fr÷mter, E
Masson's Hemangioma of Proximal Radial Artery.
Tumour like vascular lesions are rare. Here we report a rare case of tumor like vascular lesion from the radial artery. A pulsatile swelling in the forearm is usually diagnosed as a case of Aneurysm, AV fistula or highly vascular tumor. A middle aged man came to us with a painless pulsatile swelling on the lateral aspect of proximal right forearm. The ultrasound scan reported it as case of vascular tumour. Angiogram showed abnormal vascular channels, connected to the aneurysmal dialation of the proximal radial artery. Histopthological examination confirmed it as Masson's hemangioma after excision. This is a benign condition and complete excision is curative. PMID:24799774
Pinjala, Ramakrishna
NASA Astrophysics Data System (ADS)
A comparative lithogeochemical study of mainly surface rocks of the Iberian Pyrite Belt (volcanic-sedimentary sequence) and the East Pontic metallotect (volcanic island arc system with few intercalations of marine sediments) has been performed in order to find facies-independent proximity indicators of massive sulphide mineralizations. As, Sb, Tl, and Na seem to be the most promising indicator elements for primary hydrothermal exhalation and/or alteration haloes. The size of the alteration haloes largely depends on the permeability of the country rocks and is best defined by ratios such as As/Na, Sb/Na, and Tl/Na.
M÷ller, P.; Dieterle, M. A.; Dulski, P.; Germann, K.; Schneider, H.-J.; Sch³tz, W.
Current status of proximal gastric vagotomy.
Proximal gastric vagotomy is nearing its twentieth year in clinical use as an operation for peptic ulcer disease. No other acid-reducing operation has undergone as much scrutiny or study. At this time, the evidence of such studies and long-term follow-up strongly supports the use of proximal gastric vagotomy as the treatment of choice for chronic duodenal ulcer in patients who have failed medical therapy. Its application in treating the complications of peptic ulcer disease, which recently have come to represent an increasingly greater percentage of all operations done for peptic ulcer disease, is well-tested. However, initial series suggest that it should probably occupy a prominent role in treating some of these complications, particularly in selected patients, in the future. The operation has the well-documented ability to reduce gastric acid production, not inhibit gastric bicarbonate production, and also minimally inhibit gastric motility. The combination of these physiologic results after proximal gastric vagotomy, along with preservation of the normal antropyloroduodenal mechanism of gastrointestinal control, serve to allow patients with proximal gastric vagotomy the improved benefits of significantly fewer severe gastrointestinal side effects than are seen after other operations for peptic ulcer disease. PMID:2644897
Schirmer, B D
Enhancing Musical Experience through Proximal Interaction
The availability of audio content on networks has indelibly changed access to music. We extend this dynamic to wireless ad-hoc networks and present the use of dual infrastructures to extend modes of personal and interpersonal music listening. We identify two distinct forms proximal interaction, sequential and parallel, and demonstrate a musical application for each. Mobile handheld terminals become prototypical future
Atau Tanaka; Antoine Authier; Guillaume Valadon; Laurent Violette
Interpersonal Violence between College Students: Proximal Influences.
ERIC Educational Resources Information Center
This paper presents the results of a 3 year study on violence between students at the University of Maryland. The study was designed to: (1) describe the prevalence of fighting between students; (2) analyze, by gender, students' description of their most recent physical fight with another for proximal influences on these altercations; (3) analyzeģ
Marcus, Robert; Reio, Thomas; Kessler, Lauren; Cutler, Kelley; Fleury, John
Object detection system using SPAD proximity detectors
NASA Astrophysics Data System (ADS)
This paper presents an object detection system based upon the use of multiple single photon avalanche diode (SPAD) proximity sensors operating upon the time-of-flight (ToF) principle, whereby the co-ordinates of a target object in a coordinate system relative to the assembly are calculated. The system is similar to a touch screen system in form and operation except that the lack of requirement of a physical sensing surface provides a novel advantage over most existing touch screen technologies. The sensors are controlled by FPGA-based firmware and each proximity sensor in the system measures the range from the sensor to the target object. A software algorithm is implemented to calculate the x-y coordinates of the target object based on the distance measurements from at least two separate sensors and the known relative positions of these sensors. Existing proximity sensors were capable of determining the distance to an object with centimetric accuracy and were modified to obtain a wide field of view in the x-y axes with low beam angle in z in order to provide a detection area as large as possible. Design and implementation of the firmware, electronic hardware, mechanics and optics are covered in the paper. Possible future work would include characterisation with alternative designs of proximity sensors, as this is the component which determines the highest achievable accur1acy of the system.
Stark, Laurence; Raynor, Jeffrey M.; Henderson, Robert K.
Proximal tubule response in aldosterone escape.
The response of the proximal tubule to chronic aldosterone administration (15 micrograms.kg-1.day-1) was evaluated in eight conscious female mongrel dogs. Temporal profiles between hemodynamic and hormonal changes and the fractional excretions of sodium and lithium were established. Aldosterone infusion resulted in a significant decrease in urinary sodium excretion from 9.2 +/- 1.3 to 5.8 +/- 0.9 meq/h after 1 day, returning to normal by the 5th day. These changes in urinary sodium excretion were associated with significant elevations of the mean arterial pressure (MAP) from 105 +/- 5 to 111 +/- 6 mmHg and plasma atrial natriuretic factor concentrations (ANF) from 30 +/- 2 to 57 +/- 7 pg/ml beginning the 1st day of infusion. Plasma renin activity (PRA), on the other hand, was depressed by aldosterone, falling below the level of detectability. The fractional excretion of lithium increased significantly by day 2 of aldosterone infusion (from 29 +/- 3 to 44 +/- 6%), reflecting the proximal tubular response to the above changes. We conclude that the proximal tubule responds to increases in MAP and ANF and decreases in PRA during aldosterone infusion by decreasing sodium reabsorption. Subsequent nephron segments must also respond to the volume expansion produced by aldosterone, since the sustained proximal tubule natriuretic response is insufficient to explain all of escape. PMID:2521433
Gonzalez-Campoy, J M; Kachelski, J; Burnett, J C; Romero, J C; Granger, J P; Knox, F G
An Efficient Proximity Probing Algorithm for Metrology
An Efficient Proximity Probing Algorithm for Metrology F. Panahi A. Adler F. van der Stappen K Probing Algorithm for Metrology Fatemeh Panahi Aviv Adler A. Frank van der Stappen Ken Goldberg┬¦ Abstract Metrology, the theoretical and practical study of measurement, has applications in auto- mated manufacturing
Utrecht, Universiteit
Isosmotic volume reabsorption in rat proximal tubule
A theoretical model incorporating both active and passive forces has been developed for fluid reabsorption from split oil droplets in rat inter- mediate and late proximal tubule. Of necessity, simplifying assumptions have been introduced; we have assumed that the epithelium can be treated as a single membrane and that the membrane \\
R. R. Warner; C. LECHENE
Goal-Proximity Decision-Making
ERIC Educational Resources Information Center
Reinforcement learning (RL) models of decision-making cannot account for human decisions in the absence of prior reward or punishment. We propose a mechanism for choosing among available options based on goal-option association strengths, where association strengths between objects represent previously experienced object proximity. The proposedģ
Veksler, Vladislav D.; Gray, Wayne D.; Schoelles, Michael J.
Proximity correction for electron beam lithography
NASA Astrophysics Data System (ADS)
As the critical dimensions required in mask making and direct write by electron beam lithography become ever smaller, correction for proximity effects becomes increasingly important. Furthermore, the problem is beset by the fact that only a positive energy dose can be applied with an electron beam. We discuss techniques such as chopping and dose shifting, which have been proposed to meet the positivity requirement. An alternative approach is to treat proximity correction as an optimization problem. Two such methods, local area dose correction and optimization using a regularizer proportional to the informational entropy of the solution, are compared. A notable feature of the regularized proximity correction is the ability to correct for forward scattering by the generation of a 'firewall' set back from the edge of a feature. As the forward scattering width increases, the firewall is set back farther from the feature edge. The regularized optimization algorithm is computationally time consuming using conventional techniques. However, the algorithm lends itself to a microelectronics integrated circuit coprocessor implementation, which could perform the optimization faster than even the fastest work stations. Scaling the circuit to larger number of pixels is best approached with a hybrid serial/parallel digital architecture that would correct for proximity effects over 108 pixels in about 1 h. This time can be reduced by simply adding additional coprocessors.
Marrian, Christie R.; Chang, Steven; Peckerar, Martin C.
Prosthetic replacement for proximal humeral fractures.
The ideal management of complex proximal humeral fractures continues to be debatable. Evolution of proximal humeral fracture management, during the past decade, led to the implementation of many innovations in surgical treatment. Even though the pendulum of treatment seems to swing towards new trends such as locked plating, hemiarthroplasty remains a valid and reliable option that serves the patient's needs well. Hemiarthroplasty is indicated for complex proximal humeral fractures in elderly patients with poor bone stock and when internal fixation is difficult or unreliable. Hemiarthroplasty provides a better result when it is performed early post-injury. Stem height, retroversion and tuberosity positioning are technical aspects of utmost importance. Additionally reverse total shoulder arthroplasty is an alternative new modality that can be used as a primary solution in selected patients with proximal humeral fracture treatment. Failed hemiarthroplasty and fracture sequelae can be successfully managed with reverse total shoulder arthroplasty. Individual decision-making and tailored treatment that takes into consideration the personality of the fracture and the patient's characteristics should be used. PMID:19036360
Kontakis, George; Tosounidis, Theodoros; Galanakis, Ioannis; Megas, Panagiotis
Traumatic proximal tibiofibular dislocation with neurovascular injury.
23 years old male presented with inferolateral dislocation of proximal tibiofibular joint associated with popliteal artery and common peroneal nerve injury. The extension of the injury to involve the interosseus membrane up to the distal tibiofibular joint. The association of popliteal artery injury is not reported before to the best of our knowledge. PMID:23162155
Veerappa, Lokesh A; Gopalakrishna, Chetan
The Transverse Proximity Effect in Quasar Spectra
The Transverse Proximity Effect in Quasar Spectra G┬┤abor Worseck Astrophysikalisches Institut field generated by the overall population of quasars and star-forming galaxies. In the vicinity of sources of UV photons, such as luminous high-redshift quasars, the UV radiation field is enhanced due
.ĀĀ Renal glucose reabsorption is mediated by luminal sodium-glucose cotransporters (SGLTs) and basolateral facilitative glucose\\u000a transporters (GLUTs). The modulators of these transporters are not known, and their substrates glucose and Na+ are potential candidates. In this study we examined the role of glucose and Na+ filtration rate on gene expression of glucose transporters in renal proximal tubule. SGLT1, SGLT2, GLUT1
S. Vestri; M. M. Okamoto; H. S. de Freitas; R. Aparecida dos Santos; M. T. Nunes; M. Morimatsu; J. C. Heimann; U. F. Machado
Current perceptions of the role of proximal tubular fluid output (Vprox) in the regulation of Na+ and fluid balance are based largely on the results of micropuncture studies in rats that have focused on the response of Vprox to acute pharmacological, physiological, or physical interventions. Much less attention has been paid to the role of Vprox in maintaining homeostasis during
Klaus Thomsen; David G. Shirley
SummaryĀĀRabbit kidney proximal convoluted tubule (RPCT) and proximal straight tubule (RPST) cells were independently isolated and\\u000a cultured. The kinetics of the sodium-dependent glucose transport was characterized by determining the uptake of the glucose\\u000a analog alpha-methylglucopyranoside. Cell culture and assay conditions used in these experiments were based on previous experiments\\u000a conducted on the renal cell line derived from the whole kidney
Pedro L. Del Valle; Anna Trifillis; Charles E. Ruegg; Andrew S. Kane
Introduction: Penile degloving is an important step in orthoplasty. Although its role in correcting mild curvature in distal and midshaft hypospadias has been previously reported, its impact on ventral curvature (VC) correction in proximal defects warrants further investigation. Therefore, we sought to document the effect of degloving and proximal urethral dissection on VC correction in children with proximal hypospadias. Methods: We retrospectively reviewed the records of 137 patients who underwent proximal hypospadias repair between 1998 and 2006. VC, defined as mild (<30%), moderate (30%¢45%), and severe (>45%), was recorded before penile degloving and after erection test. Percent improvement in VC and need for further treatment (beyond degloving and proximal dissection) based on preoperative degree of curvature were assessed. ANOVA test was used to compare improvement among the 3 groups. Results: Mean age at repair was 14 months (range: 6¢24). Penile degloving associated with proximal urethral dissection when necessary was responsible for the improvement in the degree of curvature in 7 of 9 (77%) patients with mild VC, 23 of 44 (52%) with moderate and 35 of 84 (40%) with severe VC. Additionally, degloving alone was sufficient for VC correction in 7 of 9 (77%) mild cases, 14 of 44 (30%) moderate and only 2 of 84 (2%) severe cases. The difference among these 3 groups was statistically significant (p < 0.001). Conclusions: Penile degloving alone can correct VC. The percentage of improvement depends on the preoperative degree of curvature, with severe VC cases showing the least improvement. PMID:25553156
Weber, Bryce A.; Braga, Luis H.P.; Patel, Premal; Pippi Salle, Joao L.; Bõgli, Darius J.; Khoury, Antoine E.; Lorenzo, Armando J.
Spin¢orbit proximity effect in graphene
NASA Astrophysics Data System (ADS)
The development of spintronics devices relies on efficient generation of spin-polarized currents and their electric-field-controlled manipulation. While observation of exceptionally long spin relaxation lengths makes graphene an intriguing material for spintronics studies, electric field modulation of spin currents is almost impossible due to negligible intrinsic spin¢orbit coupling of graphene. In this work, we create an artificial interface between monolayer graphene and few-layer semiconducting tungsten disulphide. In these devices, we observe that graphene acquires spin¢orbit coupling up to 17?meV, three orders of magnitude higher than its intrinsic value, without modifying the structure of the graphene. The proximity spin¢orbit coupling leads to the spin Hall effect even at room temperature, and opens the door to spin field effect transistors. We show that intrinsic defects in tungsten disulphide play an important role in this proximity effect and that graphene can act as a probe to detect defects in semiconducting surfaces.
Avsar, A.; Tan, J. Y.; Taychatanapat, T.; Balakrishnan, J.; Koon, G. K. W.; Yeo, Y.; Lahiri, J.; Carvalho, A.; Rodin, A. S.; OÆFarrell, E. C. T.; Eda, G.; Castro Neto, A. H.; ųzyilmaz, B.
Clinical Impact of Proximal Autosomal Imbalances
Centromere-near gain of copy number can be induced by intra- or inter-chromosomal rearrangements or by the presence of a small supernumerary marker chromosome (sSMC). Interestingly, partial trisomy to hexasomy of euchromatic material may be present in clinically healthy or affected individuals, depending on origin and size of chromosomal material involved. Here we report the known minimal sizes of all centromere-near, i.e., proximal auto-somal regions in humans, which are tolerated; over 100 Mb of coding DNA are comprised in these regions. Additionally, we have summarized the typical symptoms for nine proximal autosomal regions including genes obviously sensitive to copy numbers. Overall, studying the carriers of specific chromosomal imbalances using genomics-based medicine, combined with single cell analysis can provide the genotype-phenotype correlations and can also give hints where copy-number-sensitive genes are located in the human genome. PMID:24052727
Hamid, AB; Weise, A; Voigt, M; Bucksch, M; Kosyakova, N; Liehr, T; Klein, E
REACH : the local social favor exchange : a proximal messaging system
We define proximal messaging as that category of information transaction that takes into account the physical, social and temporal proximity between the sender and recipient as it relates to the content of the message. We ...
Kizelshteyn, Boris G. (Boris Grigory)
Proximity and Investment: Evidence from Plant-Level Data
Proximity to plants makes it easier for headquarters to monitor and acquire information about plants. In this article, I estimate the effects of headquartersÆ proximity to plants on plant-level investment and productivity. ...
Giroud, Xavier
Capacitive sensors for detecting proximity and response
We have implemented an inexpensive circuit that indicates when a subject is in close proximity to a specified area of arbitrary\\u000a shape and size. The circuit can transform an easily created metal surface or a preexisting metal object into an experimental\\u000a sensor. The subject need not make physical contact with the sensor to activate the mechanism, which enables the detection
Steven W. Badelt; Aaron P. Blaisdell
Endoscopic Proximal Hamstring Repair and Ischial Bursectomy
With the significant increase in use of the arthroscope around the hip have come several less invasive techniques to manage pathologies around this joint. This technical note with a video details one such technique that allows for the endoscopic management of proximal hamstring tears and chronic ischial bursitis, which until now have been managed exclusively with much larger open approaches. This procedure allows for complete exposure of the posterior aspect of the hip in a safe, minimally invasive fashion. PMID:23766996
Dierckman, Brian D.; Guanche, Carlos A.
Pseudomonotone Variational Inequalities: Convergence of Proximal Methods
In this paper, we study the convergence of proximal methods for solving pseudomonotone (in the sense of Karamardian) variational inequalities. The main result is given in the finite-dimensional case, but we show that we still obtain convergence in an infinite-dimensional Hilbert space under a strong pseudomonotonicity or a pseudo-Dunn assumption on the operator involved in the variational inequality problem.
Examination of Derecho Environments Using Proximity Soundings
Observed upper air soundings that occurred within 2 h and 167 km of derechos were collected and analyzed to document atmospheric stability and wind shear conditions associated with long-lived convective windstorms. Sixty-seven derechos, accompanied by 113 proximity soundings, were identified during the years 1983-93. Owing to the large variability of the synoptic-scale environments associated with derechos, each derecho was further
Jeffry S. Evans; Charles A. Doswell III
Space robotic system for proximity operations
NASA Technical Reports Server (NTRS)
Key to an efficient accomplishment of space station servicing operations is the development of a scenario where the presence of man in space is well integrated with the capability of teleoperated and automatic robot system outside the stations. Results focusing on mission requirements, trajectory sequences, propulsion subsystem features, and manipulative kit characteristics relevant to proximity servicing during a Man Tended Free Flyers Robotic Mission (MTFF-RM) are illustrated.
Magnani, P. G.; Colomba, M.
Proximal Sciatic Nerve Intraneural Ganglion Cyst
Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009. PMID:20069041
Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.
Friendship, proximity, and self-disclosure
Patterns of self-disclosure were explored by means of a questionnaire administered to pairs of roommates and hallmates (non-roommates living on the same floor) in freshman dormitories. It was predicted and found that friendship was more highly related to self-disclosure in intimate than in non-intimate topic areas, whereas proximity was more highly related to disclosure in non-intimate than in intimate areas.
Zick Rubin; Stephen Shenker
Electrochemical profile for ion transport across the membrane of proximal tubular cells.
A micropuncture study was performed on the bullfrog kidney proximal tubular cells utilizing double-barreled ion-selective microelectrodes. The intracellular of Na+, K+, Cl-, HCO3(-) and pH were determined to be 21.6 mEq/L, 67.4 mEq/L, 9.9 mEq/L, 20.2 mEq/L, and 7.49 pH units, respectively. In the extracellular fluid the following activities were found: Na+, 87.4 mEq/L; K+, 2.64 mEq/L; Cl-, 72.5 mEq/L; HCO3(-), 17.9 mEq/L; and pH, 7.66. The membrane potential difference was 68.4 mV and 60.4 mV across the peritubular and brush borders, respectively. The electrochemical potential differences across the individual borders of the proximal tubule cells were separately calculated by setting the intracellular level of both electrical and chemical potentials at zero for convenience. From these analyses, the following interpretations are made. (1) In the net reabsorption of Na+, luminal Na+ enters the cell along a 95-mV gradient across the luminal border and is pumped out to the interstitium against a 104 mV gradient. In the reabsorption of bicarbonate, an uphill pump of about 69 mV (about 70% of the Na+ entry gradient) must exist on the luminal border, of which about 55 mV (80% of the bicarbonate gradient) is accounted for by the H+ secretory pump. (2) In the net reabsorption of K+, a significant K+ uptake pump must exist on the luminal border in addition to the powerful peritubular Na+-K+ exchange pump. The reabsorption of Cl- by the epithelium may take place in two ways: (a) transmembrane transport involving an uphill step of several millivolts, and (b) paracellular leakage through the tight junction. It is thought that the Na+ pump located on the basolateral border of the proximal tubule cell plays a primary role in the regulation of the movement of other ions and water. The regulatory mechanisms of these substances may involve some electrochemical feedback mechanism that works across the proximal tubular epithelium. PMID:6968864
Fujimoto, M; Naito, K; Kubota, T
Proximity effects in topological insulator heterostructures
NASA Astrophysics Data System (ADS)
Topological insulators (TIs) are bulk insulators that possess robust helical conducting states along their interfaces with conventional insulators. A tremendous research effort has recently been devoted to Tl-based heterostructures, in which conventional proximity effects give rise to a series of exotic physical phenomena. This paper reviews our recent studies on the potential existence of topological proximity effects at the interface between a topological insulator and a normal insulator or other topologically trivial systems. Using first-principles approaches, we have realized the tunability of the vertical location of the topological helical state via intriguing dual-proximity effects. To further elucidate the control parameters of this effect, we have used the graphene-based heterostructures as prototypical systems to reveal a more complete phase diagram. On the application side of the topological helical states, we have presented a catalysis example, where the topological helical state plays an essential role in facilitating surface reactions by serving as an effective electron bath. These discoveries lay the foundation for accurate manipulation of the real space properties of the topological helical state in TI-based heterostructures and pave the way for realization of the salient functionality of topological insulators in future device applications.
Li, Xiao-Guang; Zhang, Gu-Feng; Wu, Guang-Fen; Chen, Hua; Dimitrie, Culcer; Zhang, Zhen-Yu
Ferromagnet proximity effect in graphene bilayer
NASA Astrophysics Data System (ADS)
A well-known effect of ferromagnet proximity in metallic thin film results in the giant magneto-resistance (GMR). In case of graphene monolayer, the effect of dielectric ferromagnet layer (DFL) proximity leads to formation of spin-dependent electron potential and electron spin rotation in effective exchange field. We theoretically consider the ferromagnet proximity effect in graphene bilayer (GBL), where bottom and top layers are affected by arbitrary oriented DFL. Our calculations show a drastic reconstruction of energy band structure with the top DFL magnetization rotation compared to the bottom one, which is assumed to be fixed by an antiferromagnetic substrate. If the top and bottom magnetic moments are parallel and equal, we obtain a simple spin split gapless band structure. As soon as symmetry between the top and the bottom GBL is broken by rotation of top DFL magnetization, the gap is opening; it reaches the magnitude of exchange field at antiparallel configuration. Calculated conductivity of GBL strongly depends on magnetic configuration demonstrating efficiency of the new mechanism of GMR.
Semenov, Yuriy; Zavada, John; Kim, Ki Wook
Helical plating of the proximal humerus.
The ideal treatment for fractures of the proximal humerus has not been definitively agreed upon. Several recent reports have described a technique of helical plating for proximal humeral fractures, in which the proximal plate is placed laterally on the greater tuberosity, and spirals 90 degrees distally to lie on the anterior surface of the humeral shaft. The purpose of this study was to evaluate the feasibility of helical plating using a less invasive surgical approach and placing screws percutaneously in the distal plate. Dissection of 10 cadaveric upper extremity specimens was performed, using an extended anterolateral acromial approach followed by percutaneous helical plating. With the plate secured, the neurovascular structures which crossed the anterior humerus superficial to the plate were exposed and identified. Only the musculocutaneous nerve crossed anterior to the plate and was at risk for percutaneous screw placement. The nerve location was found in a consistent location among the specimens. The danger zone for the nerve location was found to be at an average of 13.5 cm from the greater tuberosity (99% CI: 12.2-14.8 cm). Though clinical experience is necessary to validate this plating technique, it appears that avoiding this danger zone in which the musculocutaneous nerve crosses will allow safe percutaneous screw placement and permit minimally invasive plating of these fractures. PMID:16129438
Gardner, Michael J; Griffith, Matthew H; Lorich, Dean G
Metallothionein isoform 3 and proximal tubule vectorial active transport
Metallothionein isoform 3 and proximal tubule vectorial active transport.BackgroundMetallothionein isoform 3 (MT-3) is expressed in the proximal tubule cells of the human kidney. The goal of the present study was to further characterize the basal expression of MT-3 in the proximal tubule and to determine if MT-3 participates in the maintenance of proximal tubule cell function.MethodsExpression of MT-3 mRNA was
Doyeob Kim; Scott H. Garrett; Mary Ann Sens; Seema Somji; Donald A. Sens
Early effects of uranyl nitrate on respiration and K sup + transport in rabbit proximal tubule
The mechanisms by which uranyl nitrate (UN) is toxic to the proximal tubule are incompletely understood. To define these further we studied potassium (K+) transport and oxygen consumption (QO2) in rabbit proximal tubule suspensions in vitro immediately after exposure to UN using extracellular O2- and K+-sensitive electrodes. UN caused a cumulative dose-dependent inhibition of proximal tubule QO2, with a threshold concentration of 5 x 10(-5) M. Kinetic analysis suggested two patterns of cell injury: a higher affinity inhibition of QO2 with a Ki of 5 x 10(-4) M, and a lower affinity inhibition of QO2 with a Ki of 10 mM. QO2 was studied in detail in the presence of these Ki concentrations of UN to define the initial cellular events. The results indicated that different cellular processes displayed different sensitivities to UN. At submillimolar concentrations UN caused progressive selective inhibition of ouabain-insensitive QO2 (15% inhibition at 2 minutes). Ouabain-sensitive QO2 and nystatin-stimulated QO2 were not affected, suggesting that Na+,K+-ATPase activity and its coupling to mitochondrial ATP synthesis were intact. Direct measurement of proximal tubule net K+ flux confirmed that Na+,K+-ATPase activity was unchanged. Similarly, UN did not inhibit basal (state 4) or ADP-stimulated (state 3) mitochondrial QO2 in digitonin-permeabilized tubules, confirming that the mitochondria were intact. In contrast, higher concentrations of UN (greater than or equal to 1 mM) caused rapid inhibition of QO2 and net K+ efflux, due to inhibition of Na+,K+-ATPase activity and mitochondrial injury.
Brady, H.R.; Kone, B.C.; Brenner, R.M.; Gullans, S.R. (Brigham and Women's Hospital, Boston, MA (USA))
Computer Vision Based Navigation for Spacecraft Proximity Operations
Computer Vision Based Navigation for Spacecraft Proximity Operations Brent Edward Tweddle, David W. Miller February 2010 SSL # 1-10 #12;#12;Computer Vision Based Navigation for Spacecraft Proximity of Technology. #12;2 #12;Computer Vision Based Navigation for Spacecraft Proximity Operations by Brent Edward
Reverse LISS plates for unstable proximal femoral fractures
The best treatment for unstable proximal femoral fractures is controversial. In this prospective study, we assessed the outcomes of reverse less invasive stabilisation system (LISS) plates for treatment of unstable proximal femoral fractures that are expected to be difficult to nail.From April 2004 to January 2007, 20 patients with unstable proximal femoral fractures that were assessed to be difficult to
Ching-Hou Ma; Yuan-Kun Tu; Shang-Won Yu; Cheng-Yo Yen; Jih-Hsi Yeh; Chin-Hsien Wu
1 16.1 INVESTIGATING DERECHO AND SUPERCELL PROXIMITY SOUNDINGS Jeffry S. Evans* NOAA of convection, we have accumulated proximity soundings associated with both derechos and discrete supercells and analyzed 113 proximity soundings near 67 derechos. The period of study was 1983-1993, and cases were
Doswell III, Charles A.
1 16.1 INVESTIGATING DERECHO AND SUPERCELL PROXIMITY SOUNDINGS Jeffry S. Evans* NOAA accumulated a number of proximity soundings associated with both derechos and discrete supercells. It can and analyzed 110 proximity soundings near 67 derechos. The period of study was from 1983-1993, and cases were
Region-based theory of discrete spaces: A proximity approach
We introduce Boolean proximity algebras as a generalization of Efremovic proximities which are suitable in reasoning about discrete regions. Following Stone's representation theorem for Boolean algebras, it is shown that each such algebra is isomorphic to a substructure of a complete and atomic Boolean proximity algebra.
Ivo D³ntsch; Dimiter Vakarelov
Luminal Alkalinization Attenuates Proteinuria-Induced Oxidative Damage in Proximal Tubular Cells
A highly acidic environment surrounds proximal tubular cells as a result of their reabsorption of HCO3?. It is unclear whether this luminal acidity affects proteinuria-induced progression of tubular cell damage. Here, we investigated the contribution of luminal acidity to superoxide (O2Ę?) production induced by oleic acid¢bound albumin (OA-Alb) in proximal tubular cells. Acidic media significantly enhanced OA-Alb¢induced O2Ę? production in the HK-2 proximal tubular cell line. Simultaneous treatment with both OA-Alb and acidic media led to phosphorylation of the intracellular pH sensor Pyk2. Highly phosphorylated Pyk2 associated with activation of Rac1, an essential subcomponent of NAD(P)H oxidase. Furthermore, knockdown of Pyk2 with siRNA attenuated the O2Ę? production induced by cotreatment with OA-Alb and acid. To assess whether luminal alkalinization abrogates proteinuria-induced tubular damage, we studied a mouse model of protein-overload nephropathy. NaHCO3 feeding selectively alkalinized the urine and dramatically attenuated the accumulation of O2Ę?-induced DNA damage and proximal tubular injury. Overall, these observations suggest that luminal acidity aggravates proteinuria-induced tubular damage and that modulation of this acidic environment may hold potential as a therapeutic target for proteinuric kidney disease. PMID:21372211
Moriguchi, Takashi; Takai, Jun; Yanagisawa-Miyazawa, Noriko; Shibata, Eisuke; Akiyama, Yasutoshi; Toyohara, Takafumi; Suzuki, Takehiro; Tanemoto, Masayuki; Abe, Takaaki; Sato, Hiroshi; Yamamoto, Masayuki; Ito, Sadayoshi
Mechanisms of adaptation to chronic respiratory acidosis in the rabbit proximal tubule.
The hyperbicarbonatemia of chronic respiratory acidosis is maintained by enhanced bicarbonate reabsorption in the proximal tubule. To investigate the cellular mechanisms involved in this adaptation, cell and luminal pH were measured microfluorometrically using (2",7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein in isolated, microperfused S2 proximal convoluted tubules from control and acidotic rabbits. Chronic respiratory acidosis was induced by exposure to 10% CO2 for 52-56 h. Tubules from acidotic rabbits had a significantly lower luminal pH after 1-mm perfused length (7.03 +/- 0.09 vs. 7.26 +/- 0.06 in controls, perfusion rate = 10 nl/min). Chronic respiratory acidosis increased the initial rate of cell acidification (dpHi/dt) in response to luminal sodium removal by 63% and in response to lowering luminal pH (7.4-6.8) by 69%. Chronic respiratory acidosis also increased dpHi/dt in response to peritubular sodium removal by 63% and in response to lowering peritubular pH by 73%. In conclusion, chronic respiratory acidosis induces a parallel increase in the rates of the luminal Na/H antiporter and the basolateral Na/(HCO3)3 cotransporter. Therefore, the enhanced proximal tubule reabsorption of bicarbonate in chronic respiratory acidosis may be, at least in part, mediated by a parallel adaptation of these transporters. PMID:2537851
Krapf, R
Unilateral isolated proximal femoral focal deficiency.
Objective. To discuss a patient with a prenatal diagnosis of unilateral isolated femoral focal deficiency. Case. Antenatal diagnosis of unilateral isolated femoral focal deficiency was made at 20 weeks of gestation. The length of left femur was shorter than the right, and fetal femur length was below the fifth percentile. Proximal femoral focal deficiency was diagnosed. After delivery, the diagnosis was confirmed with skeletal radiographs and magnetic resonance imaging. In prenatal ultrasonographic examination, the early recognition and exclusion of skeletal dysplasias is important; moreover, treatment plans should be initiated, and valuable information should be provided to the family. PMID:23984135
Do?er, Emek; K÷p³k, Sule Y; Cak?ro?lu, Yi?it; Cak?r, Ozg³r; Y³cesoy, G³lseren
Unilateral Isolated Proximal Femoral Focal Deficiency
Objective. To discuss a patient with a prenatal diagnosis of unilateral isolated femoral focal deficiency. Case. Antenatal diagnosis of unilateral isolated femoral focal deficiency was made at 20 weeks of gestation. The length of left femur was shorter than the right, and fetal femur length was below the fifth percentile. Proximal femoral focal deficiency was diagnosed. After delivery, the diagnosis was confirmed with skeletal radiographs and magnetic resonance imaging. In prenatal ultrasonographic examination, the early recognition and exclusion of skeletal dysplasias is important; moreover, treatment plans should be initiated, and valuable information should be provided to the family. PMID:23984135
Do?er, Emek; K÷p³k, ?ule Y.; Ūak?ro?lu, Yi?it; Ūak?r, ųzg³r; Y³cesoy, G³lseren
Space station proximity operations and window design
NASA Technical Reports Server (NTRS)
On-orbit proximity operations (PROX-OPS) consist of all extravehicular activity (EVA) within 1 km of the space station. Because of the potentially large variety of PROX-OPS, very careful planning for space station windows is called for and must consider a great many human factors. The following topics are discussed: (1) basic window design philosophy and assumptions; (2) the concept of the local horizontal - local vertical on-orbit; (3) window linear dimensions; (4) selected anthropomorphic considerations; (5) displays and controls relative to windows; and (6) full window assembly replacement.
Haines, Richard F.
Obesity and Supermarket Access: Proximity or Price?
Objectives. We examined whether physical proximity to supermarkets or supermarket price was more strongly associated with obesity risk. Methods. The Seattle Obesity Study (SOS) collected and geocoded data on home addresses and food shopping destinations for a representative sample of adult residents of King County, Washington. Supermarkets were stratified into 3 price levels based on average cost of the market basket. Sociodemographic and health data were obtained from a telephone survey. Modified Poisson regression was used to test the associations between obesity and supermarket variables. Results. Only 1 in 7 respondents reported shopping at the nearest supermarket. The risk of obesity was not associated with street network distances between home and the nearest supermarket or the supermarket that SOS participants reported as their primary food source. The type of supermarket, by price, was found to be inversely and significantly associated with obesity rates, even after adjusting for individual-level sociodemographic and lifestyle variables, and proximity measures (adjusted relative risk?=?0.34; 95% confidence interval?=?0.19, 0.63) Conclusions. Improving physical access to supermarkets may be one strategy to deal with the obesity epidemic; improving economic access to healthy foods is another. PMID:22698052
Aggarwal, Anju; Hurvitz, Philip M.; Monsivais, Pablo; Moudon, Anne V
Spin-orbit proximity effect in graphene.
The development of spintronics devices relies on efficient generation of spin-polarized currents and their electric-field-controlled manipulation. While observation of exceptionally long spin relaxation lengths makes graphene an intriguing material for spintronics studies, electric field modulation of spin currents is almost impossible due to negligible intrinsic spin-orbit coupling of graphene. In this work, we create an artificial interface between monolayer graphene and few-layer semiconducting tungsten disulphide. In these devices, we observe that graphene acquires spin-orbit coupling up to 17?meV, three orders of magnitude higher than its intrinsic value, without modifying the structure of the graphene. The proximity spin-orbit coupling leads to the spin Hall effect even at room temperature, and opens the door to spin field effect transistors. We show that intrinsic defects in tungsten disulphide play an important role in this proximity effect and that graphene can act as a probe to detect defects in semiconducting surfaces. PMID:25255743
Avsar, A; Tan, J Y; Taychatanapat, T; Balakrishnan, J; Koon, G K W; Yeo, Y; Lahiri, J; Carvalho, A; Rodin, A S; O'Farrell, E C T; Eda, G; Castro Neto, A H; ųzyilmaz, B
Intraosseous neurilemmoma of the proximal ulna
INTRODUCTION Neurilemmoma is a benign nerve sheath neoplasm commonly located in the soft tissue. Intraosseous neurilemmoma is rare, constituting less than 1% of primary bone tumors. PRESENTATION OF CASE A 21 year-old woman was presented with left elbow pain of 1-month duration. Plain radiographs showed a well-defined, lytic and expansile lesion of the proximal ulna. Computed tomography revealed cortical destruction and soft tissue extension. Because the tissue of origin for the tumor was uncertain, an open biopsy was performed. The specimens demonstrated a benign spindle cell tumor suggestive of a neurilemmoma, similar to a soft tissue neurilemmoma. The diagnosis of intraosseous neurilemmoma was established. Marginal excision of the soft tissue component and curettage of the lesion in the bone were performed. After 3.5 years of follow up, there is no clinical or radiographic finding to suggest any recurrence. DISCUSSION The major site of intraosseous neurilemmoma is the mandible. Occurrence in the long bone is particularly rare. Only two cases of intraosseous neurilemmoma involving the bones around the elbow have been reported to our knowledge; these cases arose in the distal humerus. We describe the first case of intraosseous neurilemmoma of the proximal ulna of the left elbow. The recommended treatment is conservative resection and bone grafting, as malignant change is extremely rare. CONCLUSION Although very rare, intraosseous neurilemmoma should be taken under consideration in the differential diagnosis of painful, radiographically benign-appearing osseous tumor around the elbow. PMID:25460435
Kito, Munehisa; Yoshimura, Yasuo; Isobe, KenÆichi; Aoki, Kaoru; Momose, Takashige; Kato, Hiroyuki
Proximal femoral osteotomy in cerebral palsy.
The purpose of this study was to examine the results of the proximal femoral osteotomy for the management of hip deformity in 32 children, aged 4 to 15 years. Twenty-two bilateral and ten unilateral procedures were performed. The indications for surgery were subluxation in 16, dislocation in two, and intoeing and femoral anteversion in 14. The average follow-up was two years and 11 months. CE angle of Wiberg, acetabular index and neck shaft angle were evaluated. The average time to regain preoperative ambulatory status was six months with intensive physical therapy. In osteotomies performed for subluxation, dislocation did not occur; roentgenographic indices showed variability in the degree of subluxation. Osteotomy performed in children older than 8 years of age produced no evidence of acetabular remodeling. THere was no recurrence with osteotomies for dislocation. In those patients with internal rotation gait, improvement resulted. Complications were few and minor. Hip dislocation in children with progressive subluxation, in spite of previous soft-tissue releases, is preventable by proximal femoral osteotomy. The inability of the roentgenographic indices to quantitate the increased stability indicates the procedure's major effect is to realign muscle forces about the hip. Treatment of the intoeing gait produced improvement of rotational deformity. PMID:7418303
Tylkowski, C M; Rosenthal, R K; Simon, S R
An improved proximity force approximation for electrostatics
A quite straightforward approximation for the electrostatic interaction between two perfectly conducting surfaces suggests itself when the distance between them is much smaller than the characteristic lengths associated with their shapes. Indeed, in the so called 'proximity force approximation' the electrostatic force is evaluated by first dividing each surface into a set of small flat patches, and then adding up the forces due two opposite pairs, the contributions of which are approximated as due to pairs of parallel planes. This approximation has been widely and successfully applied in different contexts, ranging from nuclear physics to Casimir effect calculations. We present here an improvement on this approximation, based on a derivative expansion for the electrostatic energy contained between the surfaces. The results obtained could be useful for discussing the geometric dependence of the electrostatic force, and also as a convenient benchmark for numerical analyses of the tip-sample electrostatic interaction in atomic force microscopes. - Highlights: Black-Right-Pointing-Pointer The proximity force approximation (PFA) has been widely used in different areas. Black-Right-Pointing-Pointer The PFA can be improved using a derivative expansion in the shape of the surfaces. Black-Right-Pointing-Pointer We use the improved PFA to compute electrostatic forces between conductors. Black-Right-Pointing-Pointer The results can be used as an analytic benchmark for numerical calculations in AFM. Black-Right-Pointing-Pointer Insight is provided for people who use the PFA to compute nuclear and Casimir forces.
Fosco, Cesar D. [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina) [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo, R8402AGP Bariloche (Argentina); Lombardo, Fernando C. [Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina) [Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); IFIBA (Argentina)] [Argentina; Mazzitelli, Francisco D., E-mail: firstname.lastname@example.com [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina); Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)
Artificial Topological Superconductor by the Proximity Effect
NASA Astrophysics Data System (ADS)
Topological superconductors (TSCs), featuring fully gapped bulk and gapless surface states as well as Majorana fermions, have potential applications in fault-tolerant topological quantum computing. Because TSCs are very rare in nature, an alternative way to study the TSC is to artificially introduce superconductivity into the surface states of a topological insulator through the proximity effect [X. L. Qi, T. L. Hughse, S. Raghu, and S. C. Zhang, Phys. Rev. Lett. 102, 187001 (2009); L. Fu and C. L. Kane, Phys. Rev. Lett. 100, 096407 (2008); J. Alicea, Rep. Prog. Phys. 75, 076501 (2012); C. W. J. Beenakker, Annu. Rev. Condens. Matter Phys. 4, 113 (2013)]. Here we report the experimental realization of the proximity effect-induced TSC in Bi2Te3 thin films grown on a NbSe2 substrate, as demonstrated by the density of states probed using scanning tunneling spectroscopy. We observed Abrikosov vortices and Andreev lower energy bound states on the surface of the topological insulator, with the superconducting coherence length depending on the film thickness and the magnetic field. These results also indicate that the topological surface states of Bi2Te3 thin films are superconducting and, thus, that the Bi2Te3/NbSe2 is an artificial TSC. The feasibility of fabricating a TSC with an individual Majorana fermion bound to a superconducting vortex for topological quantum computing is discussed.
Xu, Jin-Peng; Liu, Canhua; Wang, Mei-Xiao; Ge, Jianfeng; Liu, Zhi-Long; Yang, Xiaojun; Chen, Yan; Liu, Ying; Xu, Zhu-An; Gao, Chun-Lei; Qian, Dong; Zhang, Fu-Chun; Jia, Jin-Feng
Risk factors for proximal humerus fracture.
This case-control study of proximal humerus fracture included 448 incident female and male cases and 2,023 controls aged 45 years or older identified in five Northern California Kaiser Permanente Medical Centers in 1996-2001. Data were collected by using an interviewer-administered questionnaire. Some factors related to low bone mass, including number of fractures since age 45 years and low dietary calcium intake, were associated with increased risks of fracture, and factors thought to protect against bone loss, such as menopausal hormone therapy and calcium carbonate tablet use, were associated with reduced risks. Fall-related risk factors included previous falls, diabetes mellitus, and difficulty walking in dim light. Possible fall-related risk factors suggested for the first time in this study were seizure medication use (adjusted odds ratio (OR) = 2.80, 95% confidence interval (CI): 1.45, 5.42), depression (OR = 1.34, 95% CI: 0.98, 1.84), almost always using a hearing aid (OR = 1.92, 95% CI: 1.12, 3.31 vs. never prescribed), and left-handedness (OR = 2.36, 95% CI: 1.51, 3.68 vs. right-handedness). Difficulty with activities of daily living and lack of physical activity tended to be associated with increased risk. Prevention of falls among frail, osteoporotic persons would likely reduce the frequency of proximal humerus fracture. PMID:15286021
Chu, Sarah P; Kelsey, Jennifer L; Keegan, Theresa H M; Sternfeld, Barbara; Prill, Mila; Quesenberry, Charles P; Sidney, Stephen
Superconducting proximity effect in topological metals
NASA Astrophysics Data System (ADS)
Much interest in the superconducting proximity effect in three-dimensional (3D) topological insulators (TIs) has been driven by the potential to induce Majorana bound states at the interface. Most candidate materials for 3D TI, however, are bulk metals, with bulk states at the Fermi level coexisting with well-defined surface states exhibiting spin-momentum locking. In such topological metals, the proximity effect can differ qualitatively from that in TIs. By studying a model topological metal-superconductor (TM-SC) heterostructure within the Bogoliubov-de Gennes formalism, we show that the pair amplitude reaches the naked surface, unlike in a topological insulator-superconductor (TI-SC) heterostructure where it is confined to the interface. Furthermore, we predict vortex-bound-state spectra to contain a Majorana zero mode localized at the naked surface, separated from the bulk vortex-bound-state spectra by a finite energy gap in such a TM-SC heterostructure. These naked-surface-bound modes are amenable to experimental observation and manipulation, presenting advantages of TM-SC over TI-SC.
Lee, Kyungmin; Vaezi, Abolhassan; Fischer, Mark H.; Kim, Eun-Ah
The Proximity Toolkit and ViconFace: Proximity Toolkit is a toolkit that simplifies the
Diaz-Marino Department of Computer Science University of Calgary 2500 University Drive NW Calgary of Calgary 2500 University Drive NW Calgary, Alberta Canada T2N 1N4 email@example.com #12;Proximity currently wraps a Vicon motion capture system: a high-end installation that tracks infrared reflective
Greenberg, Saul
The Proximity Toolkit and ViconFace: Proximity Toolkit is a toolkit that simplifies the
University Drive NW Calgary, Alberta Canada T2N 1N4 email@example.com Saul Greenberg Department of Computer Science University of Calgary 2500 University Drive NW Calgary, Alberta Canada T2N 1N4 saul-casting) (Figure 1, bottom) The Proximity Toolkit currently wraps a Vicon motion capture system: a high
Greenberg, Saul
The mechanism of inhibition of HCO3 transport by parathyroid hormone (PTH) in the proximal tubule is not clearly defined. Previous studies in vitro have suggested that this effect is mediated via cAMP generation, which acts to inhibit Na/H exchange, resulting in cell acidification. To examine this question in vivo, intracellular pH (pHi) was measured in the superficial proximal tubule of the rat using the pH-sensitive fluoroprobes 4-methylumbelliferone (4MU) and 2',7'-bis(carboxyethyl)-(5, and 6)-carboxyfluorescein (BCECF). PTH was found to alkalinize the cell. This alkalinization suggested inhibition of basolateral base exit, which was confirmed by in situ microperfusion studies: lowering HCO3 in peritubular capillaries acidified the cell, an effect blunted by PTH. Removal of luminal Na promoted basolateral base entry, alkalinizing the cell. This response was also blunted by PTH. Readdition of luminal Na stimulated the luminal Na/H exchanger, causing an alkalinization overshoot that was partially inhibited by PTH. cAMP inhibited luminal H secretion but did not alkalinize the cell. Stimulation of phosphatidylinositol-bis-phosphate turnover by PTH was suggested by the effect to the hormone to increase cell Ca. Blocking the PTH-induced rise in cell Ca blunted the effect of the hormone to alkalinize the cell, as did inhibition of phosphatidylinositol breakdown. Furthermore, stimulation of protein kinase C by a phorbol ester and a diacylglycerol applied basolaterally alkalinized the cell and inhibited luminal H secretion. The findings indicate that both arms of the phosphatidylinositol-bis-phosphate cascade play a role in mediating the effect of PTH on the cell pH. The results are consistent with the view that PTH inhibits base exit in the proximal tubule by activation of the phosphatidylinositol cascade. The resulting alkalinization may contribute, with cAMP, to inhibit apical Na/H exchange and the PTH-induced depression of proximal HCO3 reabsorption. PMID:1314850
Pastoriza-Munoz, E; Harrington, R M; Graber, M L
Capacitive sensors for detecting proximity and response.
We have implemented an inexpensive circuit that indicates when a subject is in close proximity to a specified area of arbitrary shape and size. The circuit can transform an easily created metal surface or a preexisting metal object into an experimental sensor. The subject need not make physical contact with the sensor to activate the mechanism, which enables the detection of subjects through nonconductive materials, such as wood and plastics. The technology is readily adapted to existing experimental setups. Applications of this technology, using pigeons, rats, and mice, demonstrate its flexibility: a nose-poke/peck sensor for response or choice detection; a subject location detector that can be placed on a floor, wall, or ceiling; and a perch that detects when a bird is present. This technology can also be applied to the study of behavior in primates and many other animal species. PMID:18522073
Badelt, Steven W; Blaisdell, Aaron P
Piloting decision aid for spacecraft proximity operations
NASA Technical Reports Server (NTRS)
The concept of a decision aid to assist the piloting of a powered vehicle during a near-field (less than 2000 feet) rendezvous to another spacecraft is discussed. Using Space Shuttle rendezvous with an orbiting satellite as an example, extensive practice is normally required to successfully effect such a rendezvous with a minimum of propellant. As a rule, variations on a 'point and shoot' technique are optimized and used as much as possible. A piloting decision aid (PDA) to assist in the pointing process was conceived and is in the preliminary stages of development. This concept may be applied to Space Shuttle proximity operations for berthing with Space Station Freedom (SSF), for Shuttle rendezvous with other spacecraft, or for autonomous rendezvous of any unmanned vehicle with SSF. The concept orginated with a task order from NASA JSC for an automated piloting procedure and was influenced by an early air-to-air missile envelope display.
Pierce, Cole J.
Piloting decision aid for spacecraft proximity operations
NASA Astrophysics Data System (ADS)
The concept of a decision aid to assist the piloting of a powered vehicle during a near-field (less than 2000 feet) rendezvous to another spacecraft is discussed. Using Space Shuttle rendezvous with an orbiting satellite as an example, extensive practice is normally required to successfully effect such a rendezvous with a minimum of propellant. As a rule, variations on a 'point and shoot' technique are optimized and used as much as possible. A piloting decision aid (PDA) to assist in the pointing process was conceived and is in the preliminary stages of development. This concept may be applied to Space Shuttle proximity operations for berthing with Space Station Freedom (SSF), for Shuttle rendezvous with other spacecraft, or for autonomous rendezvous of any unmanned vehicle with SSF. The concept orginated with a task order from NASA JSC for an automated piloting procedure and was influenced by an early air-to-air missile envelope display.
Pierce, Cole J.
[Ophthalmologists in the proximity of Adolf Hitler].
Adolf Hitler met or at least knew about 5 ophthalmologists. The chair of ophthalmology in Berlin, Walther L÷hlein, personally examined Hitler's eyes at least two times. The chair of ophthalmology in Breslau, Walter Dieter, developed "air raid protection spectacles" with the aid of high representatives of the NS-system and probably Adolf Hitler himself. Heinrich Wilhelm Kranz became rector of the universities of Giessen and Frankfurt/Main. He was known as a very strict advocate of the NS-race hygiene. Werner Zabel made plans for Hitler's diet and tried to interfere with Hitler's medical treatment. Finally, Hellmuth Unger was an influential representative of the medical press and a famous writer. Three of his novels with medical topics were made into a film which Hitler probably saw. Hitler had, so to say, a small "ophthalmological proximity" which, however, did not play a significant role for himself or the NS-state. PMID:22664943
Rohrbach, J M
Parallel Proximity Detection for Computer Simulations
NASA Technical Reports Server (NTRS)
The present invention discloses a system for performing proximity detection in computer simulations on parallel processing architectures utilizing a distribution list which includes movers and sensor coverages which check in and out of grids. Each mover maintains a list of sensors that detect the mover's motion as the mover and sensor coverages check in and out of the grids. Fuzzy grids are included by fuzzy resolution parameters to allow movers and sensor coverages to check in and out of grids without computing exact grid crossings. The movers check in and out of grids while moving sensors periodically inform the grids of their coverage. In addition, a lookahead function is also included for providing a generalized capability without making any limiting assumptions about the particular application to which it is applied. The lookahead function is initiated so that risk-free synchronization strategies never roll back grid events. The lookahead function adds fixed delays as events are scheduled for objects on other nodes.
Steinman, Jeffrey S. (Inventor); Wieland, Frederick P. (Inventor)
Parallel Proximity Detection for Computer Simulation
NASA Technical Reports Server (NTRS)
The present invention discloses a system for performing proximity detection in computer simulations on parallel processing architectures utilizing a distribution list which includes movers and sensor coverages which check in and out of grids. Each mover maintains a list of sensors that detect the mover's motion as the mover and sensor coverages check in and out of the grids. Fuzzy grids are includes by fuzzy resolution parameters to allow movers and sensor coverages to check in and out of grids without computing exact grid crossings. The movers check in and out of grids while moving sensors periodically inform the grids of their coverage. In addition, a lookahead function is also included for providing a generalized capability without making any limiting assumptions about the particular application to which it is applied. The lookahead function is initiated so that risk-free synchronization strategies never roll back grid events. The lookahead function adds fixed delays as events are scheduled for objects on other nodes.
Steinman, Jeffrey S. (Inventor); Wieland, Frederick P. (Inventor)
Optical proximity stability control of ArF immersion clusters
NASA Astrophysics Data System (ADS)
Once a process is set-up in an integrated circuit (IC) manufacturer's fabrication environment, any drift in the proximity fingerprint of the cluster will negatively impact the yield. In complement to the dose, focus and overlay control of the cluster, it is therefore also of ever growing importance to monitor and maintain the proximity stability (or CD through pitch behavior) of each cluster. In this paper, we report on an experimental proximity stability study of an ASML XT:1900i cluster for a 32 nm poly process from four different angles. First, we demonstrate the proximity stability over time by weekly wafer exposure and CD through pitch measurements. Second, we investigate proximity stability from tool-to-tool. In a third approach, the stability over the exposure field (intra-field through-pitch CD uniformity) is investigated. Finally, we verify that proximity is maintained through the lot when applying lens heating correction. Monitoring and maintaining the scanner's optical proximity through time, through the lot, over the field, and from toolto- tool, involves extensive CD metrology through pitch. In this work, we demonstrate that fast and precise CD through pitch data acquisition can be obtained by scatterometry (ASML YieldStarTM S-100), which significantly reduces the metrology load. The results of this study not only demonstrate the excellent optical proximity stability on a XT:1900i exposure cluster for a 32 nm poly process, but also show how scatterometry enables thorough optical proximity control in a fabrication environment.
Van Look, Lieve; Bekaert, Joost; D'havķ, Koen; Laenens, Bart; Vandenberghe, Geert; Cheng, Shaunee; Schreel, Koen; Gemmink, Jan-Willem
Axial heterogeneity of sodium-bicarbonate cotransport in proximal straight tubule of rabbit kidney
Intracellular microelectrodes were used to investigate rheogenic Na+(HCO3-)n cotransport in different segments of isolated proximal straight tubule (PST) of rabbit kidney. In the first portion (S2 segment) the peritubular cell membrane potentialVb averaged -46.0, SE▒1.3 mV (n=20), while in the terminal portion (S3 segment) it averaged -68.3, SE▒2.5 mV (n=10). This difference may reflect different modes of anion permeation across
Y. Kondo; E. Friimter
Intracellular pH (pHi) and its basolateral regulation were studied in isolated proximal-proximal and distal-proximal segments of garter snake (Thamnophis spp.) renal tubules with oil-filled lumens in HEPES-buffered and in HEPES-HCO-3-buffered media (pH 7.4 at 25 degrees C). pHi was measured with the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF) under resting conditions and in response to NH4Cl pulse. Resting pHi (approximately 7.1-7.2) and its response to and rate of recovery (dpHi/dt) from an NH4Cl pulse were not affected by the presence or absence of HCO-3 in either segment. Rate of recovery was depressed by Na+ removal in distal-proximal segments only and only in HEPES buffer. It was not affected by removal of Cl- or of both Na+ and Cl- or by reduction in membrane potential through addition of Ba2+ (5 mM) or high K+ (75 mM) in either segment in either HEPES or HEPES-HCO-3 buffer. The Na+/H+ exchange inhibitor ethylisopropylamiloride (EIPA) (100 microM) and the anion exchange inhibitor DIDS (100 microM) reduced dpHi/dt in the distal-proximal segments only and only in HEPES-HCO-3 buffer. The H+-ATPase inhibitor bafilomycin (1 microM), H+-K+-ATPase and K+/NH+4 exchange inhibitor Schering 28080 (10-100 microM), organic cation efflux inhibitor tetrapentylammonium (25 microM-20 mM), and K+ channel blocker tetraethylammonium (20 mM) had no effect on dpHi/dt in either segment. These data do not clearly support basolateral regulation of pHi in snake proximal renal tubules by commonly recognized Na+-dependent or Na+-independent acid or base transporters. PMID:10362747
Dantzler, W H; Serrano, O K; Abbott, D E; Kim, Y K; Brokl, O H
Regulation of intracellular pH in avian renal proximal tubules.
In proximal tubules isolated from chicken transitional nephrons, intracellular pH (pHi), measured with the pH-sensitive fluorescent dye 2'.7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF), was approximately 7.3-7.4 under control conditions [N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered medium with pH 7.4 at 39 degrees C] and was reduced to approximately 6.8 in response to NH4Cl pulse. The rate of recovery of pHi (dpHi/dt) from this acid level to the resting level and the resting pHi were 1) significantly reduced by the removal of Na+ from the bath, 2) significantly increased by the removal of Cl from the bath, and 3) unchanged by the removal of both Na+ and Cl from the bath. The addition of either amiloride or 4,4'-diisothiocyanostilbene-2,2'-disulfonate to the bath reduced dpHi/dt to about the same extent as the removal of Na+. These data suggest that both Na(+)-coupled and Cl-coupled acid-base fluxes at the basolateral membrane are involved in determining the resting pHi and the rate of recovery of pHi after acidification. The most likely possibilities appear to be a basolateral Na+/Hi exchanger, a basolateral Na(+)-coupled Cl/HCO3 exchanger, a basolateral Na(+)-HCO3(-)CO(3)2 cotransporter, and a basolateral Na(+)-independent Cl-/HCO3 exchanger. PMID:9039027
Kim, Y K; Brokl, O H; Dantzler, W H
Proximity Operations and Docking Sensor Development
NASA Technical Reports Server (NTRS)
The Next Generation Advanced Video Guidance Sensor (NGAVGS) has been under development for the last three years as a long-range proximity operations and docking sensor for use in an Automated Rendezvous and Docking (AR&D) system. The first autonomous rendezvous and docking in the history of the U.S. Space Program was successfully accomplished by Orbital Express, using the Advanced Video Guidance Sensor (AVGS) as the primary docking sensor. That flight proved that the United States now has a mature and flight proven sensor technology for supporting Crew Exploration Vehicles (CEV) and Commercial Orbital Transport Systems (COTS) Automated Rendezvous and Docking (AR&D). NASA video sensors have worked well in the past: the AVGS used on the Demonstration of Autonomous Rendezvous Technology (DART) mission operated successfully in spot mode out to 2 km, and the first generation rendezvous and docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on Space Shuttle flights in 1997 and 1998. 12 Parts obsolescence issues prevent the construction of more AVGS units, and the next generation sensor was updated to allow it to support the CEV and COTS programs. The flight proven AR&D sensor has been redesigned to update parts and add additional capabilities for CEV and COTS with the development of the Next Generation AVGS at the Marshall Space Flight Center. The obsolete imager and processor are being replaced with new radiation tolerant parts. In addition, new capabilities include greater sensor range, auto ranging capability, and real-time video output. This paper presents some sensor hardware trades, use of highly integrated laser components, and addresses the needs of future vehicles that may rendezvous and dock with the International Space Station (ISS) and other Constellation vehicles. It also discusses approaches for upgrading AVGS to address parts obsolescence, and concepts for minimizing the sensor footprint, weight, and power requirements. In addition, the testing of the brassboard and proto-type NGAVGS units will be discussed along with the use of the NGAVGS as a proximity operations and docking sensor.
Howard, Richard T.; Bryan, Thomas C.; Brewster, Linda L.; Lee, James E.
Proximity and territory versus space in regional science
Empirical evidence tends to show that regional development occurs only in certain places. Therefore, one can ask the central question of the role of physical proximity in economic development processes. Economists try to answer this question through the concept of externalities, but this does not explain why certain externalities are linked with physical proximity. In this paper the author tries
O Crevoisier
PROXIMITY OF INFORMATION IN GAMES WITH INCOMPLETE INFORMATION by Dov Monderer * and Dov Samet of Management, Tel Aviv University, Tel Aviv, Israel #12;Abstract Existing notions of proximity of information fail to satisfy desired continuity properties of equilibria in games with incomplete information. We
Monderer, Dov
Antibody-mediated injury to proximal tubules in Heymann nephritis
Antibody-mediated injury to proximal tubules in Heymann nephritis. To evaluate the hypothesis that antibody-mediated damage to proximal tubules (PT) could be a feature of Heymann nephritis (HN), we studied the kidneys of rats in different stages of the disease by light, immunofluorescence (IF), transmission, and scanning electron microscopy. The observations of morphology were correlated with titers of circulating antibodies directed
Donna L Mendrick; Bernice Noble; Jan R Brentjens; Giuseppe A Andres
Modular endoprosthetic replacement for metastatic tumours of the proximal femur
BACKGROUND AND AIMS: Endoprosthetic replacements of the proximal femur are commonly required to treat destructive metastases with either impending or actual pathological fractures at this site. Modular prostheses provide an off the shelf availability and can be adapted to most reconstructive situations for proximal femoral replacements. The aim of this study was to assess the clinical and functional outcomes following
Coonoor R Chandrasekar; Robert J Grimer; Simon R Carter; Roger M Tillman; Adesegun T Abudu
Resonant Proximity Connector for Two-Dimensional Sensor Implantation
In this paper, we propose a stable proximity connector RFC (resonant proximity connector) to TDC (two-dimensional communication) sheet. RFC is an electrode whose length is a quarter of the electromagnetic wavelength. The induced resonance around the electrode reduces the impedance between the connector and TDC sheet, which allows sensor chips to communicate with TDC sheet stably. Since the resonance depends
Hiromasa Chigusa; Yasutoshi Makino; Hiroyuki Shinoda
Proximity of Information in Games with Incomplete Information
Existing notions of proximity of information fail to satisfy desired continuity properties of equilibria in games with incomplete information. We demonstrate this failure and propose a topology on information structures which is the minimal one that satisfies those continuity requirements. This topology is defined in terms of the common belief players have about the proximity of each player's information. 1.
Finding Aggregate Proximity Relationships and Commonalities in Spatial Data Mining
Finding Aggregate Proximity Relationships and Commonalities in Spatial Data Mining Edwin M. Knorr proximity commonalities (i.e., features) that apply to most, if not all, of the n clusters? Regarding derive many meaningful commonalities that cannot be found otherwise. Index Terms---spatial knowledge
Knorr, Edwin M.
Group Proximity Measure for Recommending Groups in Online Social Networks
There are currently, thousands of online social networks (OSN) available, each of which hosts millions of users. Users make new friendship links, join groups on diverse topics, share opinions and thus help in building a big knowledge repository. In this paper we study the problem of defining proximity measure between groups (communities) of OSN. Understanding the proximity among the groups
Barna Saha; Lise Getoor
Scintillation proximity assay of arginine methylation.
Methylation of arginine residues, catalyzed by protein arginine methyltransferases (PRMTs), is one important protein posttranslational modification involved in epigenetic regulation of gene expression. A fast and effective assay for PRMT can provide valuable information for dissecting the biological functions of PRMTs, as well as for screening small-molecule inhibitors of arginine methylation. Currently, among the methods used for PRMT activity measurement, many contain laborious separation procedures, which restrict the applications of these assays for high-throughput screening (HTS) in drug discovery. The authors report here a mix-and-measure method to measure PRMT activity based on the principle of scintillation proximity assay (SPA). In this assay, (3)H-AdoMet was used as methyl donor, and biotin-modified histone H4 peptide served as a methylation substrate. Following the methylation reaction catalyzed by PRMTs, streptavidin-coated SPA beads were added to the reaction solution, and SPA signals were detected by a MicroBeta scintillation counter. No separation step is needed, which simplifies the assay procedure and greatly enhances the assay speed. Particularly, the miniaturization and robustness suggest that this method is suited for HTS of PRMT inhibitors. PMID:21821785
Wu, Jiang; Xie, Nan; Feng, You; Zheng, Y George
Proximal spinal muscular atrophy: current orthopedic perspective
Spinal muscular atrophy (SMA) is a hereditary neuromuscular disease of lower motor neurons that is caused by a defective ōsurvival motor neuronö (SMN) protein that is mainly associated with proximal progressive muscle weakness and atrophy. Although SMA involves a wide range of disease severity and a high mortality and morbidity rate, recent advances in multidisciplinary supportive care have enhanced quality of life and life expectancy. Active research for possible treatment options has become possible since the disease-causing gene defect was identified in 1995. Nevertheless, a causal therapy is not available at present, and therapeutic management of SMA remains challenging; the prolonged survival is increasing, especially orthopedic, respiratory and nutritive problems. This review focuses on orthopedic management of the disease, with discussion of key aspects that include scoliosis, muscular contractures, hip joint disorders, fractures, technical devices, and a comparative approach of conservative and surgical treatment. Also emphasized are associated complications including respiratory involvement, perioperative care and anesthesia, nutrition problems, and rehabilitation. The SMA disease course can be greatly improved with adequate therapy with established orthopedic procedures in a multidisciplinary therapeutic approach. PMID:24399883
Haaker, Gerrit; Fujak, Albert
Semiconductor detectors with proximity signal readout
Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need.
Asztalos, Stephen J. [XIA, LLC, Hayward, CA (United States)
Effects of thrust reversing in ground proximity
NASA Technical Reports Server (NTRS)
The changes in stability and control characteristics encountered by a thrust reversing aircraft during its final approach, landing, and ground roll are described. These changes include a strong pitch-up accompanied by the loss of horizontal tail and aileron control effectiveness. The magnitude of reverser induced changes in ground effect are much larger than corresponding changes in free air. Some unexpected unsteady motions exhibited in wind tunnel by an aircraft model with reversers operating in ground proximity are also described. The cause of this oscillatory behavior was determined to be an unsteady interaction between the wall jets formed by impingement of reverser jets on the ground and the on-coming free stream. Time histories of rolling moments measured by the wind tunnel balance or support system were removed and frequencies were scaled by Strouhal number to full scale. Corrected time series were used to simulate the motion of a fighter aircraft with thrust reversers in ground effect. The simulation predicted large roll angles and nose down attitude at touchdown. Some phenomena of jet attachment to solid surfaces are discussed and areas for future research are recommended.
Joshi, P. B.; Hughes, R. V.
Proximal relationships between PTSD and drinking behavior
Co-morbid PTSD and alcohol use disorders are both common and debilitating. However, many of these studies rely on cross-sectional studies that obscure more complex relationships between PTSD and drinking. Event-level studies allow for examination of proximal relationships between PTSD and drinking. Among women (n=136 with past sexual victimization, n=40 no past trauma history), a two-part mixed hurdle model was used to examine daily PTSD and drinking. On days women experienced more intrusive and behavioral avoidance symptoms, they were more likely to drink. For a 2 SD increase in symptoms, there was a 5% increased likelihood of drinking, and for a 2 SD increase in dysphoric symptoms or negative affect, women drank approximately half drink less. Daily-level coping self-efficacy moderated the association between distress and drinking (IRR=0.91, p<0.01). Women who reported less coping drank more as their distress increased on a certain day whereas women who reported more coping drank about the same regardless of distress. Overall, findings suggest that specific PTSD symptoms are associated with higher alcohol use and that these relationships are moderated by daily coping self-efficacy. Implications of these findings for informing models of PTSD/AUD comorbidity, as well as clinical implications will be discussed. PMID:25511723
Kaysen, Debra; Stappenbeck, Cynthia; Rhew, Issac; Simpson, Tracy
Proximal relationships between PTSD and drinking behavior.
Co-morbid PTSD and alcohol use disorders are both common and debilitating. However, many of these studies rely on cross-sectional studies that obscure more complex relationships between PTSD and drinking. Event-level studies allow for examination of proximal relationships between PTSD and drinking. Among women (n=136 with past sexual victimization, n=40 no past trauma history), a two-part mixed hurdle model was used to examine daily PTSD and drinking. On days women experienced more intrusive and behavioral avoidance symptoms, they were more likely to drink. For a 2 SD increase in symptoms, there was a 5% increased likelihood of drinking, and for a 2 SD increase in dysphoric symptoms or negative affect, women drank approximately half drink less. Daily-level coping self-efficacy moderated the association between distress and drinking (IRR=0.91, p<0.01). Women who reported less coping drank more as their distress increased on a certain day whereas women who reported more coping drank about the same regardless of distress. Overall, findings suggest that specific PTSD symptoms are associated with higher alcohol use and that these relationships are moderated by daily coping self-efficacy. Implications of these findings for informing models of PTSD/AUD comorbidity, as well as clinical implications will be discussed. PMID:25511723
Kaysen, Debra; Stappenbeck, Cynthia; Rhew, Issac; Simpson, Tracy
[Traumatic lesions of the proximal tibial epiphysis].
36 fractures of the tibia involving the proximal tibial epiphyseal cartilage were treated in 35 patients at the Accident Hospital Lorenz B÷hler, Vienna over a ten-year period from 1980 to 1989. The average age at injury was 13.2 years. Most common concomitant injuries were ruptures of the ACL and/or MCL associated with meniscal lesions in type III- and IV-fractures and fractures of the fibula in type II injuries. We saw two associated aggravating problems as defined by a compartment-syndrome of the lower leg with one immediate peroneal-nerve palsy, but lesion or disruption of the popliteal artery was not observed. 26 patients were treated conservatively and nine patients had to be operated on. Long-term follow-up (means 6.4 years) was available in 28 cases. Premature epiphyseal closure was seen in three cases and one of them developed an axis angulation in the sense of genu recurvatum but operative correction was not necessary. Unsatisfactory results were stated in four cases due to their knee instability or posttraumatic painful arthrosis. There was no case of growth disturbance with axis deformation or angulation requiring surgical revision. PMID:1636220
Rappold, G
Introduction In mammals, internal Na+ homeostasis is maintained through Na+ reabsorption via a variety of Na+ transport proteins with mutually compensating functions, which are expressed in different segments of the nephrons. In zebrafish, Na+ homeostasis is achieved mainly through the skin/gill ionocytes, namely Na+/H+ exchanger (NHE3b)-expressing H+-ATPase rich (HR) cells and Na+-Cl- cotransporter (NCC)-expressing NCC cells, which are functionally homologous to mammalian proximal and distal convoluted tubular cells, respectively. The present study aimed to investigate whether or not the functions of HR and NCC ionocytes are differentially regulated to compensate for disruptions of internal Na+ homeostasis and if the cell differentiation of the ionocytes is involved in this regulation pathway. Results Translational knockdown of ncc caused an increase in HR cell number and a resulting augmentation of Na+ uptake in zebrafish larvae, while NHE3b loss-of-function caused an increase in NCC cell number with a concomitant recovery of Na+ absorption. Environmental acid stress suppressed nhe3b expression in HR cells and decreased Na+ content, which was followed by up-regulation of NCC cells accompanied by recovery of Na+ content. Moreover, knockdown of ncc resulted in a significant decrease of Na+ content in acid-acclimated zebrafish. Conclusions These results provide evidence that HR and NCC cells exhibit functional redundancy in Na+ absorption, similar to the regulatory mechanisms in mammalian kidney, and suggest this functional redundancy is a critical strategy used by zebrafish to survive in a harsh environment that disturbs body fluid Na+ homeostasis. PMID:23924428
Missense mutation T485S alters NBCe1-A electrogenicity causing proximal renal tubular acidosis.
Mutations in SLC4A4, the gene encoding the electrogenic Na(+)-HCO3(-) cotransporter NBCe1, cause severe proximal renal tubular acidosis (pRTA), growth retardation, decreased IQ, and eye and teeth abnormalities. Among the known NBCe1 mutations, the disease-causing mechanism of the T485S (NBCe1-A numbering) mutation is intriguing because the substituted amino acid, serine, is structurally and chemically similar to threonine. In this study, we performed intracellular pH and whole cell patch-clamp measurements to investigate the base transport and electrogenic properties of NBCe1-A-T485S in mammalian HEK 293 cells. Our results demonstrated that Ser substitution of Thr485 decreased base transport by ~50%, and importantly, converted NBCe1-A from an electrogenic to an electroneutral transporter. Aqueous accessibility analysis using sulfhydryl reactive reagents indicated that Thr485 likely resides in an NBCe1-A ion interaction site. This critical location is also supported by the finding that G486R (a pRTA causing mutation) alters the position of Thr485 in NBCe1-A thereby impairing its transport function. By using NO3(-) as a surrogate ion for CO3(2-), our result indicated that NBCe1-A mediates electrogenic Na(+)-CO3(2-) cotransport when functioning with a 1:2 charge transport stoichiometry. In contrast, electroneutral NBCe1-T485S is unable to transport NO3(-), compatible with the hypothesis that it mediates Na(+)-HCO3(-) cotransport. In patients, NBCe1-A-T485S is predicted to transport Na(+)-HCO3(-) in the reverse direction from blood into proximal tubule cells thereby impairing transepithelial HCO3(-) absorption, possibly representing a new pathogenic mechanism for generating human pRTA. PMID:23636456
Zhu, Quansheng; Shao, Xuesi M; Kao, Liyo; Azimov, Rustam; Weinstein, Alan M; Newman, Debra; Liu, Weixin; Kurtz, Ira
Missense mutation T485S alters NBCe1-A electrogenicity causing proximal renal tubular acidosis
Mutations in SLC4A4, the gene encoding the electrogenic Na+-HCO3? cotransporter NBCe1, cause severe proximal renal tubular acidosis (pRTA), growth retardation, decreased IQ, and eye and teeth abnormalities. Among the known NBCe1 mutations, the disease-causing mechanism of the T485S (NBCe1-A numbering) mutation is intriguing because the substituted amino acid, serine, is structurally and chemically similar to threonine. In this study, we performed intracellular pH and whole cell patch-clamp measurements to investigate the base transport and electrogenic properties of NBCe1-A-T485S in mammalian HEK 293 cells. Our results demonstrated that Ser substitution of Thr485 decreased base transport by ?50%, and importantly, converted NBCe1-A from an electrogenic to an electroneutral transporter. Aqueous accessibility analysis using sulfhydryl reactive reagents indicated that Thr485 likely resides in an NBCe1-A ion interaction site. This critical location is also supported by the finding that G486R (a pRTA causing mutation) alters the position of Thr485 in NBCe1-A thereby impairing its transport function. By using NO3? as a surrogate ion for CO32?, our result indicated that NBCe1-A mediates electrogenic Na+-CO32? cotransport when functioning with a 1:2 charge transport stoichiometry. In contrast, electroneutral NBCe1-T485S is unable to transport NO3?, compatible with the hypothesis that it mediates Na+-HCO3? cotransport. In patients, NBCe1-A-T485S is predicted to transport Na+-HCO3? in the reverse direction from blood into proximal tubule cells thereby impairing transepithelial HCO3? absorption, possibly representing a new pathogenic mechanism for generating human pRTA. PMID:23636456
Shao, Xuesi M.; Kao, Liyo; Azimov, Rustam; Weinstein, Alan M.; Newman, Debra; Liu, Weixin; Kurtz, Ira
Characterisation of human tubular cell monolayers as a model of proximal tubular xenobiotic handling
The aim of this study was to determine whether primary human tubular cell monolayers could provide a powerful tool with which to investigate the renal proximal tubular handling of xenobiotics. Human proximal and distal tubule/collecting duct cells were grown as monolayers on permeable filter supports. After 10 days in culture, proximal tubule cells remained differentiated and expressed a wide palette of transporters at the mRNA level including NaPi-IIa, SGLT1, SGLT2, OCT2, OCTN2, OAT1, OAT3, OAT4, MDR1, MRP2 and BCRP. At the protein level, the expression of a subset of transporters including NaPi-IIa, OAT1 and OAT3 was demonstrated using immunohistochemistry. Analysis of the expression of the ATP binding cassette efflux pumps MDR1, MRP2 and BCRP confirmed their apical membrane localisation. At the functional level, tubule cell monolayers retain the necessary machinery to mediate the net secretion of the prototypic substrates; PAH and creatinine. PAH secretion across the monolayer consisted of the uptake of PAH across the basolateral membrane by OAT1 and OAT3 and the apical exit of PAH by a probenecid and MK571-sensitive route consistent with actions of MRP2 or MRP4. Creatinine secretion was by OCT2-mediated uptake at the basolateral membrane and via MDR1 at the apical membrane. Functional expression of MDR1 and BCRP at the apical membrane was also demonstrated using a Hoechst 33342 dye. Similarly, measurement of calcein efflux demonstrated the functional expression of MRP2 at the apical membrane of cell monolayers. In conclusion, human tubular cell monolayers provide a powerful tool to investigate renal xenobiotic handling.
Brown, Colin D.A. [Epithelial Research Group, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH (United Kingdom)], E-mail: firstname.lastname@example.com; Sayer, Rachel; Windass, Amy S.; Haslam, Iain S. [Epithelial Research Group, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH (United Kingdom); Broe, Marc E. de; D'Haese, Patrick C.; Verhulst, Anja [Laboratory of Pathophysiology, University of Antwerp (Belgium)
Secretion and contraluminal uptake of dicarboxylic acids in the proximal convolution of rat kidney.
The transport of dicarboxylic acids in the proximal convolution was investigated by measuring: a) the zero net flux transtubular concentration difference of DL-methyl-succinate, b) its 2-s influx from the interstitium into tubular cells, and c) its 3.5-s efflux from the tubular lumen. With the first method a luminal concentration exceeding the peritubular concentration was observed, thus indicating a net active transtubular secretion of this slowly metabolized substance. All transport steps, luminal and contraluminal , as well as the overall transport, were Na+-dependent and inhibited by lithium (apparent Ki approximately equal to 1.8 mmol/l). The overall transport of methylsuccinate , as well as the contraluminal influx into proximal tubular cells, could be inhibited by paraaminohippurate and H2-DIDS with an apparent Ki of approximately equal to 1.8 mmol/l, by taurocholate with an apparent Ki approximately equal to 3.1 mmol/l and by pyruvate with an apparent Ki approximately equal to 5 mmol/l, but not by sulfate, thiosulfate, L-lactate, oxalate and urate. As judged from the inhibition of contraluminal methylsuccinate influx by 48 dicarboxylic acids (aliphatic and aromatic), a specificity pattern was observed similar to that of inhibition of luminal efflux of 2-oxoglutarate [22]: a preference of dicarboxylates in the transconfiguration with a chain length of 4-5 carbons; little change in the inhibitory potency with CH3-, OH-, SH- and O=, but strong reduction with a NH3+ in the 2 position; only a small reduction of inhibitory potency with 2,3 disubstituted SH and OH analogs; preference of the dicarboxylic benzene in the 1,4 position and of the diacetyl benzene in the 1,2 position. The data indicate a Na+-dependent dicarboxylic transport system at the contraluminal cell side of the proximal tubule which is very similar to the luminal transport system for dicarboxylic acids. PMID:6728645
Ullrich, K J; Fasold, H; Rumrich, G; Kl÷ss, S
A Cl- channel activated by parathyroid hormone in rabbit renal proximal tubule cells.
Previous data suggested an active Cl- conductance in the renal proximal convoluted tubule, although single channel conductance and regulation were not found. We have investigated the presence and regulation of the Cl- channel in proximal convoluted tubules by patch clamp analysis. The current-voltage relationship of whole cells with 130 mM NaCl in the pipette was nonlinear. The addition of 1-34 PTH (10(-8) M), forskolin, or cAMP significantly increased whole cell Cl- conductance. We found a single Cl- channel in excised apical membranes possessing conductance of 33 picosiemens (pS) at positive and 22.5 pS at negative potential, which was blocked by 4,4'-diisothiocyanostilbene-2,2'- disulfonic acid (10(-4) M) and was selective to Cl- (Cl/Na = 10). The channel was activated by prolonged membrane depolarization, by a catalytic subunit of protein kinase A (PKA), or by purified kinase C (PKC), but not by Ca2+ (1 microM) inside the membrane. During cell-attached patch clamping, the channel was similarly activated by PTH, phorbol ester, or dibutyryl cAMP in a dose-dependent manner. To investigate second messenger contributions to the PTH-action, the PTH-evoked channels were modified further by the subsequent addition of several blockers of the second messengers. This suggested that PKA and PKC were involved in Cl- channel activation. We therefore conclude that renal proximal convoluted tubule cells possess an apical Cl- channel activated by PTH via the PKA and PKC pathways. PMID:1715885
Suzuki, M; Morita, T; Hanaoka, K; Kawaguchi, Y; Sakai, O
Transport Magnetic Proximity Effects in Platinum
NASA Astrophysics Data System (ADS)
Platinum (Pt) metal, being non-magnetic and having a strong spin-orbit coupling interaction, has been central in detecting pure spin current and establishing most of the recent spin-based phenomena. Thus, it is important to ascertain the transport and magnetic characteristics of thin Pt films in contact with a ferromagnet. In this work, we use both electric and thermal means to conclusively show the transport magnetic proximity effects (MPE) of thin Pt film in contact with ferromagnetic insulator YIG. At thicknesses comparable to, and less than, the spin diffusion length, the strong ferromagnetic characteristics in Pt films on YIG are indistinguishable from those of ferromagnetic permalloy on YIG. [1] The MPE occurs at the interface and decreases exponentially away from the interface, concentrating in only a few monolayers. As a result, the pure spin current detected by a thin Pt is tainted with a spin polarized current. The pure spin current phenomena, such as the inverse spin Hall effect and the spin Seebeck effect, have been contaminated with the anomalous Hall effect and the anomalous Nernst effect respectively. These results raise serious questions about the suitability, and the validity, of using Pt in establishing pure spin current phenomena; on the other hand, a much stronger spin-based effect can be induced by the MPE at the interface. This research is in collaboration with X. Fin, Y. P. Chen, J. Wu, and J. Q. Xiao (University of Delaware), T. Y. Chen (Arizona State University) and D. Qu, W. G. Wang, and C. L. Chien (The Johns Hopkins University).[4pt] [1] S. Y. Huang et al., Phys. Rev. Letts. 109, 107204 (2012).
Huang, Ssu-Yen
Hypospadias and Residential Proximity to Pesticide Applications
BACKGROUND: Experimental evidence suggests pesticides may be associated with hypospadias. OBJECTIVE: Examine the association of hypospadias with residential proximity to commercial agricultural pesticide applications. METHODS: The study population included male infants born from 1991 to 2004 to mothers residing in 8 California counties. Cases (n = 690) were ascertained by the California Birth Defects Monitoring Program; controls were selected randomly from the birth population (n = 2195). We determined early pregnancy exposure to pesticide applications within a 500-m radius of motherÆs residential address, using detailed data on applications and land use. Associations with exposures to physicochemical groups of pesticides and specific chemicals were assessed using logistic regression adjusted for maternal race or ethnicity and age and infant birth year. RESULTS: Forty-one percent of cases and controls were classified as exposed to 57 chemical groups and 292 chemicals. Despite >500 statistical comparisons, there were few elevated odds ratios with confidence intervals that excluded 1 for chemical groups or specific chemicals. Those that did were for monochlorophenoxy acid or ester herbicides; the insecticides aldicarb, dimethoate, phorate, and petroleum oils; and adjuvant polyoxyethylene sorbitol among all cases; 2,6-dinitroaniline herbicides, the herbicide oxyfluorfen, and the fungicide copper sulfate among mild cases; and chloroacetanilide herbicides, polyalkyloxy compounds used as adjuvants, the insecticides aldicarb and acephate, and the adjuvant nonyl-phenoxy-poly(ethylene oxy)ethanol among moderate and severe cases. Odds ratios ranged from 1.9 to 2.9. CONCLUSIONS: Most pesticides were not associated with elevated hypospadias risk. For the few that were associated, results should be interpreted with caution until replicated in other study populations. PMID:24167181
Yang, Wei; Roberts, Eric M.; Kegley, Susan E.; Wolff, Craig; Guo, Liang; Lammer, Edward J.; English, Paul; Shaw, Gary M.
Dual pathology proximal median nerve compression of the forearm.
We report an unusual case of synchronous pathology in the forearm- the coexistence of a large lipoma of the median nerve together with an osteochondroma of the proximal ulna, giving rise to a dual proximal median nerve compression. Proximal median nerve compression neuropathies in the forearm are uncommon compared to the prevalence of distal compression neuropathies (eg Carpal Tunnel Syndrome). Both neural fibrolipomas (Refs. 1,2) and osteochondromas of the proximal ulna (Ref.Ā3) in isolation are rare but well documented. Unlike that of a distal compression, a proximal compression of the median nerve will often have a definite cause. Neural fibrolipoma, also called fibrolipomatous hamartoma are rare, slow-growing, benign tumours of peripheral nerves, most often occurring in the median nerve of younger patients. To our knowledge, this is the first report of such dual pathology in the same forearm, giving rise to a severe proximal compression of the median nerve. In this case, the nerve was being pushed anteriorly by the osteochondroma, and was being compressed from within by the intraneural lipoma. This unusual case highlights the advantage of preoperative imaging as part of the workup of proximal median nerve compression. PMID:23707555
Murphy, Siun M; Browne, Katherine; Tuite, David J; O'Shaughnessy, Michael
A 17 year old with isolated proximal tibiofibular joint arthritis
The proximal tibiofibular joint (TFJ) is rarely affected in rheumatic diseases, and we frequently interpret pain of the lateral knee as the result of overuse or trauma. Nonetheless, the TFJ is a synovial joint that communicates with the tibiofemoral joint in a proportion of patients. While proximal TFJ arthritis has been rarely associated with existing spondyloarthritis, isolated TFJ arthritis as the presenting manifestation of spondyloarthritis has not yet been described. Here, we report the clinical and radiographic presentation of an adolescent with chronic proximal TFJ arthritis heralding spondyloarthritis highly suggestive of ankylosing spondylitis. PMID:23302539
Neck angulation (NA) is an important risk factor for type 1 proximal endoleaks following stenting of abdominal aortic aneurysms. The Aorfix (Lombard Medical, Oxon, UK) is a new flexible stent graft designed to overcome this issue. The aim of this study was to compare the endoleak flow rate (EFR) in relation to NA between the Aorfix and other manufactured stent grafts. A flow model with silicone proximal and distal necks was used. EFRs corresponding to 10 neck angles between 0 and 70 degrees were measured. Eight stent grafts were tested: Aorfix, Ancure (Guidant, Indianapolis, IN), Powerlink (Endologix, Irvine, CA), AneuRx (Medtronic, Sunnyvale, CA), Excluder (W.L. Gore & Associates, Flagstaff, AZ), Zenith and Zenith-Flex (Cook Inc., Bloomington, IN), and Lifepath (Edwards Lifesciences, Irvine, CA). For all stent grafts except the Aorfix, the EFR was greater than at baseline for NA >or= 30 degrees (p < .01). The EFR at NA >or= 30 degrees was lower with the Aorfix compared with the other stent grafts (p < .01). NA had no influence on the EFR with the Aorfix. The Aorfix may decrease the incidence of proximal type 1 endoleak in patients with a severely angulated aortic neck. PMID:16390649
Albertini, Jean-Noļl; DeMasi, Maria-Angela; Macierewicz, Jan; El Idrissi, Redouane; Hopkinson, Brian R; Clķment, Claude; Branchereau, Alain
29 CFR 452.104 - Proximity of notice to election.
Code of Federal Regulations, 2010 CFR
...DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS GENERAL STATEMENT CONCERNING THE ELECTION PROVISIONS OF THE LABOR-MANAGEMENT REPORTING AND DISCLOSURE ACT OF 1959 Election Procedures; Rights of Members ¦ 452.104 Proximity of notice to...
Light-operated proximity detector with linear output
A light-operated proximity detector is described in which reflected light intensity from a surface whose proximity to the detector is to be gauged is translated directly into a signal proportional to the distance of the detector from the surface. A phototransistor is used to sense the reflected light and is connected in a detector circuit which maintains the phototransistor in a saturated state. A negative feedback arrangement using an operational amplifier connected between the collector and emitter of the transistor provides an output at the output of the amplifier which is linearly proportional to the proximity of the surface to the detector containing the transistor. This direct proportional conversion is true even though the light intensity is varying with the proximity in proportion to the square of the inverse of the distance. The detector may be used for measuring the distance remotely from any target surface.
Simpson, Marc L. (Harriman, TN); McNeilly, David R. (Maryville, TN)
Computer vision based navigation for spacecraft proximity operations
The use of computer vision for spacecraft relative navigation and proximity operations within an unknown environment is an enabling technology for a number of future commercial and scientific space missions. This thesis ...
Tweddle, Brent Edward
The primary proximal point method for minimizing a differentiable function f : ...... The incomplete measurements are given by b = A(L0+S0). ...... D. F. Sun, and P. Tseng, ōHankel matrix rank minimization with applications to system identification
Planning and scheduling proximity operations for autonomous orbital rendezvous
This thesis develops a mixed integer programming formulation to solve the proximity operations scheduling problem for autonomous orbital rendezvous. The algorithm of this thesis allows the operator to specify planned modes, ...
Guerra, Christopher J., 1978-
Deleting the TGF-? Receptor Attenuates Acute Proximal Tubule Injury
TGF-? is a profibrotic growth factor in CKD, but its role in modulating the kidneyÆs response to AKI is not well understood. The proximal tubule epithelial cell, which is the main cellular target of AKI, expresses high levels of both TGF-? and its receptors. To determine how TGF-? signaling in this tubular segment affects the response to AKI, we selectively deleted the TGF-? type II receptor in the proximal tubules of mice. This deletion attenuated renal impairment and reduced tubular apoptosis in mercuric chloride¢induced injury. In vitro, deficiency of the TGF-? type II receptor protected proximal tubule epithelial cells from hydrogen peroxide¢induced apoptosis, which was mediated in part by Smad-dependent signaling. Taken together, these results suggest that TGF-? signaling in the proximal tubule has a detrimental effect on the response to AKI as a result of its proapoptotic effects. PMID:23160515
Vadivelu, Sangeetha; Neelisetty, Surekha; Srichai, Manakan B.; Paueksakon, Paisit; Pozzi, Ambra; Harris, Raymond C.
Technical tips: dualplate fixation technique for comminuted proximal humerus fractures.
The authors report dualplate fixation technique for providing stable fixation in comminuted proximal humerus fractures. This technique has been used for proximal humerus fractures with metaphyseal comminution and provides excellent anatomical reduction and neck shaft angle (NSA). The recently locking plate is clinically more widely used due to its small size, low rigidity, high elasticity, and biomechanical properties such as fixed initial angle and rotational stability. However, in severely comminuted complex type proximal metaphyseal humerus fractures, the use of locking plate alone does not provide stable fixation, leading to complications such as varus collapse, anterior-posterior angulation, screw cutout, nonunion, malunion, and metal failure. Therefore, a more robust and enhanced fixation method, the dual plating technique using the locking compression plate (Proximal Humeral Internal Locking System and Variable Angle Locking Compression Plate) was developed. PMID:24813097
Choi, Sungwook; Kang, Hyunseong; Bang, Hyeongsig
Adamantinoma of the proximal femur: a case report
Adamantinoma is a rare low-grade malignant bone tumor with an indolent course. The tibia is involved in 85%¢90% of long-bone cases. We encountered a patient with primary adamantinoma of the proximal femur. A 60-year-old woman fell and fractured her proximal left femur in the area of a cystic lesion. She underwent an osteosynthesis procedure, and bone union was obtained. After
Sadao Ii; Hiroyuki Tsuchiya; Koutaro Takazawa; Katsuro Tomita
Proximity functions for electrons up to 10 keV
Proximity functions for electrons up to 10 keV in water are computed from simulated particle tracks. Numerical results are given for the differential functions t(x) and the integral functions T(x). Basic characteristics of these functions and their connections to other microdosimetric quantities are considered. As an example of the applicability of the proximity functions, the quantity y/sub D/ for spheres is derived from t(x).
Chmelevsky, D. (Institut fuer Medizinische Strahlenkunde der Universitaet Wuerzburg, Germany); Kellerer, A.M.; Terrissol, M.; Patau, J.P.
Digital Image Enhancement Improves Diagnosis of Nondisplaced Proximal Femur Fractures
Today most emergency room radiographs are computerized, making digital image enhancement a natural advancement to improve\\u000a fracture diagnosis. We compared the diagnosis of nondisplaced proximal femur fractures using four different image enhancement\\u000a methods using standard DICOM (Digital Imaging and Communications in Medicine) after window-leveling optimization. Twenty-nine\\u000a orthopaedic residents and specialists reviewed 28 pelvic images consisting of 25 occult proximal femur
Itamar Busheri Botser; Amir Herman; Ram Nathaniel; Dan Rappaport; Aharon Chechik
Proximal Femoral Reconstructions with Bone Impaction Grafting and Metal Mesh
Extensive circumferential proximal cortical bone loss is considered by some a contraindication for impaction bone grafting\\u000a in the femur. We asked whether reconstruction with a circumferential metal mesh, impacted bone allografts, and a cemented\\u000a stem would lead to acceptable survival in these patients. We retrospectively reviewed 14 patients (15 hips) with severe proximal\\u000a femoral bone defects (average, 12Ācm long; 14
MartĒn A. Buttaro; Fernando Comba; Francisco Piccaluga
Predictors of Proximal Neoplasia in Patients Without Distal Adenomatous Pathology
BACKGROUND:Previous colorectal cancer screening studies have observed that some patients may have advanced proximal neoplasia without distal findings. Since these studies have included only gender, age, and family history as risk factors, they are limited in their ability to identify predictors of isolated proximal neoplasia.METHODS:Data were collected from the charts of 1,988 patients who presented for colonoscopy. Information gathered included
Joseph C. Anderson; Zvi Alpern; Catherine R. Messina; Patricia Hubbard; Roger Grimson; Peter F. Ells; Douglas L. Brand
Integrated Control of Na Transport along the Nephron.
The kidney filters vast quantities of Na at the glomerulus but excretes a very small fraction of this Na in the final urine. Although almost every nephron segment participates in the reabsorption of Na in the normal kidney, the proximal segments (from the glomerulus to the macula densa) and the distal segments (past the macula densa) play different roles. The proximal tubule and the thick ascending limb of the loop of Henle interact with the filtration apparatus to deliver Na to the distal nephron at a rather constant rate. This involves regulation of both filtration and reabsorption through the processes of glomerulotubular balance and tubuloglomerular feedback. The more distal segments, including the distal convoluted tubule (DCT), connecting tubule, and collecting duct, regulate Na reabsorption to match the excretion with dietary intake. The relative amounts of Na reabsorbed in the DCT, which mainly reabsorbs NaCl, and by more downstream segments that exchange Na for K are variable, allowing the simultaneous regulation of both Na and K excretion. PMID:25098598
Palmer, Lawrence G; Schnermann, J³rgen
This review summarizes the strategy of cellular immortalization based on the principle of targeted oncogenesis in transgenic mice, used to establish models of transimmortalized renal proximal tubule cells, referred to as PKSV-PCT and PKSV-PR-cells, and collecting duct principal cells, referred to as mpkCCD(cl4) cells. These cell lines have maintained for long-term passages the main biochemical and functional properties of the parental cells from which they were derived. Proximal tubule PKSV-PCT and PKSV-PR cells have been proved to be suitable cell systems for toxicological and pharmacological studies. They also permitted the establishment of a model of multidrug-resistant (MDR) renal epithelial tubule cells, PKSV-PR(col50), which have served for the study of both MDR-dependent extrusion of chemotherapeutic drugs and inappropriate accumulation of weak base anthracyclines in intracellular acidic organelles. The novel collecting duct cell line mpkCCD(cl4), which has maintained the characteristics of tight epithelial cells, in particular Na(+) absorption stimulated by aldosterone, has been extensively used for pharmacological studies related to the regulation of ion transport. These cells have permitted the identification of several aldosterone-induced proteins playing a key role in the regulation of Na(+) absorption mediated by the epithelial Na(+) channel ENaC. Recent studies have also provided evidence that these cell lines represent valuable cell systems for the study of host-pathogen interactions and the analysis of the role of renal tubule epithelial cells in the induction of inflammatory response caused by uropathogens that may lead to severe renal damage. PMID:17219250
Chassin, C; Bens, M; Vandewalle, A
Duodenal switch for intractable reflux gastroesophagitis after proximal gastrectomy.
Reflux gastroesophagitis is a common postgastrectomy complication after proximal gastrectomy, and conservative treatments including protease inhibitors and proton pump inhibitors are effective in most patients. Here we report a patient with severe reflux gastroesophagitis after proximal gastrectomy, in whom surgical treatment of duodenal switch was effective. An 80-year-old man complained of intractable heartburn, anorexia, and body weight loss after having undergone proximal gastrectomy, with reconstruction by esophagogastrostomy with valvuloplasty and pyloroplasty, for early gastric cancer 14 months before referral to our department. Oral administration of protease inhibitors and proton pump inhibitors was ineffective. Laboratory evaluation showed poor nutritional status. On endoscopic examination, we noted the redness, bleeding, and multiple erosions in the esophagus and the gastric remnant. He was diagnosed to have severe gastroesophagitis due to reflux of duodenal juice into the gastric remnant and esophagus. We performed duodenal switch to divert duodenal juice from the gastric remnant and esophagus; the duodenum was transected 2 cm distal to the pylorus, the duodenal distal end was closed, and a 50-cm Roux limb from the proximal jejunum was anastomosed to the proximal end of the duodenum. The heartburn disappeared postoperatively, and endoscopic examination revealed marked improvement of the reflux gastroesophagitis. One year postoperatively, the patient is free from symptoms including heartburn. His body weight increased, and laboratory data showed improvement in nutritional status. In conclusion, the duodenal switch may be surgical treatment of choice for intractable reflux gastroesophagitis after proximal gastrectomy. PMID:23803250
Someya, Soutoku; Shibata, Chikashi; Tanaka, Naoki; Kudoh, Katsuyoshi; Naitoh, Takeshi; Miura, Koh; Unno, Michiaki
Design and Clinical Application of Proximal Humerus Memory Connector
NASA Astrophysics Data System (ADS)
Treatment for comminuted proximal humerus fractures and nonunions are a substantial challenge for orthopedic surgeons. Plate and screw fixation does not provide enough stability to allow patients to begin functional exercises early after surgery. Using shape memory material nickel titanium alloy, we designed a new device for treating severe comminuted proximal humerus fractures that accommodates for the anatomical features of the proximal humerus. Twenty-two cases of comminuted fracture, malunion, and nonunion of the proximal humerus were treated with the proximal humeral memory connector (PHMC). No external fixation was needed after the operation and patients began active shoulder exercises an average of 8 days after the operation. Follow-up evaluation (mean 18.5 months) revealed that bone healing with lamellar bone formation occurred an average of 3.6 months after surgery for the fracture cases and 4.5 months after surgery for the nonunion cases. Average shoulder function was 88.5 according to the criteria of Michael Reese. PHMC is an effective new device to treat comminuted proximal humerus fractures and nonunions. The use of this device may reduce the need for shoulder joint arthroplasty.
Xu, Shuo-Gui; Zhang, Chun-Cai
Proximal tubular function in dogs with thoracic caval constriction
The effect of saline infusion on proximal sodium reabsorption was compared in normal dogs and in dogs with acute or chronic partial thoracic vena cava obstruction. After acute vena cava obstruction, proximal fractional sodium reabsorption rose by 74%. During continued caval obstruction, saline loading strikingly reduced proximal reabsorption but sodium excretion remained minimal. In chronic caval dogs, saline loading reduced proximal fractional sodium reabsorption by 31% but sodium excretion in the micropunctured kidney was only 41 ?Eq/min. After saline infusion in normal dogs, proximal fractional sodium reabsorption fell 39% while unilateral sodium excretion rose to 584 ?Eq/min. Nephron filtration rate was also measured before and after saline loading in normal and chronic caval dogs in both repunctured and fresh tubules. There was a marked increase in nephron filtration rate in repunctured tubules and no change in freshly punctured tubules in both groups. The effect of saline loading on nephron filtration rate in normal and chronic caval dogs was similar, therefore, whether repunctured or fresh nephrons were considered. We conclude that saline infusion depresses proximal sodium reabsorption in acute and chronic TVC dogs. Since saline loading markedly increases distal delivery without a concomitant natriuresis, enhanced distal reabsorption must play a major role in the sodium retention exhibited by chronic caval dogs. Redistribution of filtrate does not appear to be a factor in this sodium retention. PMID:5116206
Auld, R. Brewer; Alexander, Edward A.; Levinsky, Norman G.
In isolated, nonperfused chicken proximal tubules from both loopless reptilian-type and long-looped mammalian-type nephrons, resting intracellular pH (pHi), measured with pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF), was approximately 7.1 under control HCO3- conditions [20 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)/5 mM HCO3(-)-buffered medium with pH 7.4 at 37 degrees C] and was reduced to approximately 6.8 in response to NH4Cl pulse. The rate of recovery of pHi (dpHi/dt) from this level to the resting level in proximal tubules from both nephron types was (1) significantly reduced by the removal of Na+ or both Na+ and Cl- from the bath, and (2) unaffected by the removal of Cl- from the bath or the presence of a high K+ concentration or Ba2+ in the bath. In proximal tubules from long-looped mammalian-type, but not loopless reptilian-type, nephrons, dpHi/dt was significantly reduced by the addition of either 5-(N-ethyl-N-isopropyl) amiloride (EIPA) or 4,4'-diisothiocyanostilbene-2,2'disulfonate (DIDS) to the bath. These data suggest that a Na+/H+ exchanger and most likely a Na(+)-dependent Cl-/HCO3- exchanger are involved in basolateral regulation of pHi in mammalian-type nephrons whereas none of the commonly identified basolateral acid-base transporters appear to be involved in regulation of pHi in reptilian-type nephrons. PMID:10404646
Brokl, O H; Martinez, C L; Kim, Y K; Abbott, D E; Dantzler, W H
The aim of the present study was to investigate the use of a radial artery graft (RAG) for bypass of the proximal superficial temporal artery (STA) to proximal posterior cerebral artery (PCA) by posterior oblique transzygomatic subtemporal approach as an alternative to the external carotid artery (ECA) to PCA anastomosis. We conducted an anatomical and technical study at a university hospital. Five adult cadaveric specimens were dissected. A preauricular vertical skin incision was used. The trunk of STA was identified. A 30 degrees oblique posterior zygomatic arch osteotomy and microcraniotomy was performed. The dura of the middle cranial fossa was then opened. The temporal lobe was retracted, the interpeduncular and ambient cisterns were opened, and the P2 segment of the PCA was exposed. The proximal side of the RAG was anastomosed with the proximal STA and the distal side was anastomosed with the P2 segment. The mean caliber of the proximal STA was 2.25 +/- 0.35 mm. The mean diameter of the P(2) was 2.2 +/- 0.2 mm. The average length of the RAG was 56 +/- 3.2 mm. The mean caliber of the proximal and the distal sides of the graft was 2.5 +/- 0.25 mm and 2.3 +/- 0.15 mm, respectively. Because the proximal STA to proximal PCA bypass uses a short RAG and their calibers are over 2 mm, this bypass technique can provide a sufficient blood flow and may be a reasonable alternative over ECA to PCA bypass using long grafts. PMID:18773233
Ulku, Cagatay Han; Cicekcibasi, Aynur Emine; Cengiz, Sahika Liva; Ustun, Mehmet Erkan; Buyukmumcu, Mustafa
Predictive factors of proximal advanced neoplasia in the large bowel
Introduction The aim of the study was to evaluate the impact of sex, age, family history and distal findings on the risk of proximal advanced neoplasia (cancer or advanced adenoma) in the large bowel. Material and methods Records for 10 111 asymptomatic participants of the Colonoscopy Screening Program (CSP), recruited from the Warsaw region between 2000 and 2004, were analyzed. A multivariate logistic regression model was used to estimate the impact of sex, age, family history and most advanced distal lesions on the occurrence of proximal advanced neoplasia. To enhance comparability of the study two definitions of the proximal colon were applied ¢ either the splenic flexure (1st) or the bend between the descending and sigmoid colon (2nd definition) represented the boundary. Results One hundred and thirty-three (1st) and 167 patients (2nd definition) were found to have at least one advanced neoplastic lesion in the proximal part, respectively. Eleven and 14 patients were found to have carcinoma, while in 130 and 163 patients at least one proximal advanced adenoma appeared. Men were at twice as high risk of having advanced neoplasia in the proximal colon than women (OR = 1.94, 95% CI: 1.31¢2.87, p = 0.001 or OR = 1.69, 95% CI: 1.20¢2.40, p = 0.003, respectively). The presence of distal advanced neoplastic lesions was associated with 3.5 times higher risk of proximal advanced neoplasia (OR = 3.58, 95% CI: 2.00¢6.43, p < 0.0001 or OR = 3.41, 95% CI: 1.95¢5.96, p < 0.0001), respectively. Conclusions The results may confirm some limitation of flexible sigmoidoscopy in the screening settings in comparison with colonoscopy, at least in men and people with distal advanced neoplasia. PMID:25097578
Mroz, Andrzej; Kaminski, Michal F.; Kraszewska, Ewa; Orlowska, Janina; Regula, Jaroslaw
Oral sodium bicarbonate (NaHCO3) is widely used to treat acidosis in patients with renal failure. However, no data are available in man on the effects on proximal renal tubular protein catabolism or markers of tubular injury. We have developed methods to allow such studies, and both increased tubular catabolism of 99mTc-labelled aprotinin (Apr*), as well as tubular damage were found in association with increased ammonia (NH3) excretion in patients with nephrotic range proteinuria. We now examine the effects of reducing renal ammoniogenesis, without altering proteinuria, using oral NaHCO3 in 11 patients with mild/moderate renal impairment and proteinuria. Renal tubular catabolism of Apr* was measured before and after NaHCO3 by renal imaging (Kidney uptake, K% of dose) and urinary excretion of free 99mTcO4- (metabolism, Met% of dose/h) over 26 h. Fractional degradation (Frac) was calculated from Met/K (/h). Fresh urine was also analyzed for NH3 excretion every fortnight from 6/52 before treatment. Total urinary N-acetyl-beta-D-glucose-aminidase (NAG) and the more tubulo-specific NAG "A2" were measured. 51CrEDTA clearance and 99mTc-MAG 3 TER were also assessed. After NaHCO3 Met over 26 h was significantly reduced (from 1.3 +/- 0.2% of dose/h to 0.9 +/- 0.1% dose/hr, p < 0.005), as was Frac of Apr* (from 0.06 +/- .006/h to 0.04 +/- 0.005/hr, p < 0.003). NH3 excretion also fell significantly (from 0.9 +/- 0.2 mmol/h to 0.2 +/- 0.05 mmol/h, p < 0.007), as did both total urinary NAG (from 169 mumol/24 h, 74-642 mumol/24 h to 79 mumol/ 24 h, 37-393 mumol/24 h, p < 0.01), and the NAG 'A2' isoenzyme (from 81.5 mumol/24 h, 20-472 mumol/24 h to 35.0 mumol/24 h, 6-388 mumol/24 h, p < 0.001). Proteinuria remained unaltered, and there was no change in blood pressure nor in glomerular haemodynamics. Oral NaHCO3 may thus pro-tect the proximal renal tubule and help delay renal disease progression. PMID:9574465
Rustom, R; Grime, J S; Costigan, M; Maltby, P; Hughes, A; Taylor, W; Shenkin, A; Critchley, M; Bone, J M
This study examines the ontogeny of cellular pH regulation in renal proximal tubule cells (RPTC). RPTC from 8- to 40-day-old Sprague-Dawley rats (RPTC-8 to RPTC-40) were studied after 48 h of primary culture. Intracellular pH (pHi) was measured by quantitative fluorescence microscopy using 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Recordings were made under basal conditions and after imposing a cytoplasmic alkalosis and acidosis using 15 mM NH4+ salt. The net recovery rate (dpHi/dt) from intracellular acidosis increases significantly between 10 and 12 days of age from 0.39 +/- 0.04 to 0.54 +/- 0.06 pH units/min (P < 0.05, n = 10 vs. 6). This increase can be completely accounted for by an increase in the rate of amiloride (100 microM)-inhibitable Na(+)-H+ exchange (0.29 +/- 0.04 vs. 0.42 +/- 0.05 pH units/min, P < 0.05, n = 6 vs. 6). The rate of Na(+)-H+ exchange increases similarly in RPTC-10 and RPTC-40 when the transmembrane Na+ gradient is increased by Na+ depleting the cells (48 and 49%, respectively). The amiloride-insensitive recovery is Na+ independent and insensitive to 4-acetamido-4'-isothiocyanostilbene-2-2'-disulfonic acid (SITS, 500 microM) (range 0.08-0.14 pH units/min). The net recovery rate from intracellular alkalosis is significantly lower in RPTC-10 than in RPTC-40 (0.16 +/- 0.02 vs. 0.28 +/- 0.02 pH units/min, P < 0.01, n = 4 vs. 5). SITS (500 microM) inhibits the recovery by 27 +/- 8 and 26 +/- 9%, respectively, whereas amiloride has no effect.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1329559
Ekblad, H; Aperia, A; Larsson, S H
Proximal Femoral Nail Antirotation in Treatment of Fractures of Proximal Femur
Introduction: Fractures of the proximal femur and hip are relatively common injuries in adults and common source of morbidity and mortality among the elderly. Many methods have been recommended for the treatment of intertrochanteric fractures. Material and methods: We retrospective analyzed all the patients with fractures of the hip treated with proximal femoral nail antirotation (PFNA) at the Clinic of Orthopedic and Traumatology, University Clinical Centre Tuzla from the first of January 2012 to 31 December 2012 years. The study included 63 patients averaged 73.6▒11.9 years (range, 29 to 88 years). Fracture type was classified as intertrochanteric (Arbeitsgemeinschaft f³r Osteosynthesefragen classification 31.A.1, A.2 and A.3) and subtrochanteric fractures (Seinsheimer classification). Results and discussion: The ratio between the genders female-male was 1.6:1. There was statistically significant difference prevalence of female compared to male patients (p=0.012). There were 31 left and 32 right hip fractured. Low energy trauma was the cause of fractures in 57(90.5%) patients. Averaged waiting time for hospitalization was 3.2▒7.5 days (range, 0 to 32 days). 44 patients were admitted the same day upon injuring. The average waiting time for the treatment was 3.6▒5.7 days. The ratio between with or without co-existent disease was 4.7:1. During the three months postoperatively with ASA score 3 and 4 six patients died. There were no significant differences in deaths from ASA score 1 and 2 (p=0.52). Reoperation for the treatment of implant or fracture-related complications was required in three (4.7%) patients (infection, reimplantation and extraction). Three patient developed deep vein thrombosis. Statistically significant difference was found in the deaths in the first three months compared to the next three months (p=0.02). We found statistically significant difference between pre-injury and postoperative mobility score (p=0.0001). Conclusion: PFNA is an excellent device for osteosynthesis as it can be easily inserted. Moreover, it provides stable fixation, which allows early full weightbearing mobilization of the patient.
Sadic, Sahmir; Custovic, Svemir; Jasarevic, Mahir; Fazlic, Mirsad; Smajic, Nedim; Hrustic, Asmir; Vujadinovic, Aleksandar; Krupic, Ferid
Proximal Tibiofibular Joint Ganglion CystsExcision, Recurrence, and Joint Arthrodesis
Objective: Proximal tibiofibular joint proximal tibiofibular joint cysts are rare entities that can cause disability. Excision remains the traditional surgical treatment. Cyst recurrence has been a problem. This study reviews one of the largest series of patients with proximal tibiofibular joint cysts and evaluates the role of a new surgical option, proximal tibiofibular joint fusion.Methods: Thirteen patients were admitted to
Shana Miskovsky; Christopher Kaeding; Lawrence Weis
[Hormonal component of the postprandial motility response of the proximal stomach in dogs].
The motility of a proximal gastric pouch, that has been extinsically denervated by autotransplantation, has been studied in 4 dogs. In the same time, the electrical activity of the duodenum was recorded with AgAgCl electrodes. Recordings were made in the fasting state and after oral administration of 250 ml NaCl 154 mM solutions containing 15 kcal/kg of either glucose, peptides or lipids, or 3 X 5 kcal/kg of a mixture of these three nutrients. The results showed, in the fasting state, that a cyclic activity took place in the denervated gastric pouch corresponding to the myoelectric complex observed at the same time in the duodenum. After feeding the dogs with any nutrient solution, we observed: 1) a decrease in pouch pressure; 2) an interruption of the cyclic activity in both the pouch and duodenum. A fasting motility resumed simultaneously in both the pouch and duodenum. These results indicate that hormonal agents are involved in the motility of the proximal stomach as well as in the postprandial interruption of the myoelectric complex. PMID:6454473
Schang, J C; Kelly, K A
Roles of Renal Proximal Tubule Transport in Acid/Base Balance and Blood Pressure Regulation
Sodium-coupled bicarbonate absorption from renal proximal tubules (PTs) plays a pivotal role in the maintenance of systemic acid/base balance. Indeed, mutations in the Na+-HCO3? cotransporter NBCe1, which mediates a majority of bicarbonate exit from PTs, cause severe proximal renal tubular acidosis associated with ocular and other extrarenal abnormalities. Sodium transport in PTs also plays an important role in the regulation of blood pressure. For example, PT transport stimulation by insulin may be involved in the pathogenesis of hypertension associated with insulin resistance. Type 1 angiotensin (Ang) II receptors in PT are critical for blood pressure homeostasis. Paradoxically, the effects of Ang II on PT transport are known to be biphasic. Unlike in other species, however, Ang II is recently shown to dose-dependently stimulate human PT transport via nitric oxide/cGMP/ERK pathway, which may represent a novel therapeutic target in human hypertension. In this paper, we will review the physiological and pathophysiological roles of PT transport. PMID:24982885
Nakamura, Motonobu; Shirai, Ayumi; Yamazaki, Osamu; Suzuki, Masashi; Horita, Shoko; Yamada, Hideomi
Role of renal proximal tubule transport in thiazolidinedione-induced volume expansion.
Thiazolidinediones (TZDs), pharmacological activators of peroxisome-proliferator-activated receptors ? (PPAR?), significantly improve insulin resistance and lower plasma glucose concentrations. However, the use of TZDs is associated with plasma volume expansion, the mechanism of which has been a matter of controversy. Originally, PPAR?-mediated enhanced transcription of the epithelial Na channel (ENaC) ? subunit was thought to play a central role in TZD-induced volume expansion. However, later studies suggested that the activation of ENaC alone could not explain TZD-induced volume expansion. We have recently shown that TZDs rapidly stimulate sodium-coupled bicarbonate absorption from renal proximal tubule (PT) in vitro and in vivo. TZD-induced transport stimulation was dependent on PPAR?/Src/EGFR/ERK, and observed in rat, rabbit and human. However, this stimulation was not observed in mouse PTs where Src/EGFR is constitutively activated. Analysis in mouse embryonic fibroblast cells confirmed the existence of PPAR?/Src-dependent non-genomic signaling, which requires the ligand binding ability but not the transcriptional activity of PPAR?. The TZD-induced enhancement of association between PPAR? and Src supports an obligatory role for Src in this signaling. These results support the view that TZD-induced volume expansion is multifactorial. In addition to the PPAR?-dependent enhanced expression of the sodium transport system(s) in distal nephrons, the PPAR?-dependent non-genomic stimulation of renal proximal transport may be also involved in TZD-induced volume expansion. PMID:24175252
Seki, George; Endo, Yoko; Suzuki, Masashi; Yamada, Hideomi; Horita, Shoko; Fujita, Toshiro
Intracellular pH regulation in the S3 segment of the rabbit proximal tubule in HCO3- -free solutions
We used the absorbance spectrum of 4',5'-dimethyl-5-(and 6) carboxyfluorescein to measure intracellular pH (pHi) in the isolated, perfused S3 segment of the rabbit proximal tubule. Experiments were conducted in HCO3- -free solutions. pHi recovered from an acid load imposed by an NH4+ prepulse, indicating the presence of one or more active acid-extrusion mechanisms. Removal of Na+ from bath and lumen caused pHi to decrease by approximately 0.6, whereas Na+ readdition caused complete pHi recovery. Removal of Na+ from the bath caused only a slow pHi decrease that was enhanced about fourfold when Na+ was subsequently removed from the lumen also. Similarly, the pHi recovery produced by the readdition of Na+ to the bath and lumen was about ninefold faster than when Na+ was returned to the bath only. Amiloride (1-2 mM) inhibited the pHi recovery that was elicited by returning 15 or 29 mM Na+ to lumen by only approximately 30%. However, in the absence of external acetate (Ac-), 1 mM amiloride inhibited approximately 66% of the pHi recovery induced by the readdition of 29 mM Na+ to the lumen only. The removal of external Ac- reduced the pHi recovery rate from an NH4+-induced acid load by approximately 47%, and that elicited by Na+ readdition, by approximately 67%. Finally, when bilateral removal of Na+ was maintained for several minutes, pHi recovered from the initial acidification, slowly at first, and then more rapidly, eventually reaching a pHi approximately 0.1 higher than the initial one. This Na+-independent pHi recovery was not significantly affected by lowering [HEPES]o from 32 to 3 mM or by adding N'N'-dicyclohexylcarbodiimide (10(-4) M) to the lumen, but it was reduced approximately 57% by iodoacetate (0.5 mM) plus cyanide (1 mM). We conclude that in the nominal absence of HCO3-, three transport systems contribute to acid extrusion by S3 cells: (a) a Na+-independent mechanism, possibly an H+ pump; (b) a Na-H exchanger, confined primarily to the luminal membrane; and (c) an Ac- and luminal Na+- dependent mechanism. The contribution of these three mechanisms to total acid extrusion, assessed by the rapid readdition of Na+, was approximately 13, approximately 30, and approximately 57%, respectively. PMID:3225554
Proximal femoral arthroplasty in patients undergoing revision hip arthroplasty.
Bone loss represents one of the greatest challenges in revision joint surgery. A retrospective review was conducted of both radiographic and clinical outcomes of eleven patients who underwent revision arthroplasty using a long extensively porous coated cylindrical femoral component. All patients' femurs presented with severe proximal femoral bone loss (Paprosky class IIIB and IV). With a mean follow-up of 8 years (2 to 14) we report no femoral revisions and one acetabular revision to a constrained cup secondary to instability. All patients were clinically and radiographically stable. We did not observe any issue with proximal stress shielding or component loosening. The article reports that in patients with severe proximal femoral bone loss, extensively porous-coated non-modular stems are a viable option offering stable and predictable outcomes. PMID:25134742
March, Gerard M J; Dehghan, Niloofar; Gala, Luca; Spangehl, Mark J; Kim, Paul R
Proximity effects and vortex dynamics in superconducting heterostructures
NASA Astrophysics Data System (ADS)
Vortex lattice dynamics has been studied in thin Nb superconducting films sputtered on top of a dense triangular array of V dots with and without an intermediate SiO2 insulating layer. While the insulating layer modifies only slightly the Nb film corrugation, it reduces superconducting commensurability effects (CE) substantially. This implies that superconducting commensurability is dominated by proximity effects. Moreover, the HC2 (T) phase diagram of the sample without an insulating layer shows a parabolic temperature dependence near TC and critical temperature oscillations with the periodicity of the matching field. Therefore, strong proximity effects locally suppress superconductivity leading to a superconducting mesh. When the proximity effect is decreased by an insulating layer, HC2(T) follows the expected linear T dependence.
Carreira, S. J.; Bekeris, V.; Rosen, Y. J.; Monton, C.; Schuller, Ivan K.
Common relationships among proximate composition components in fishes
Relationships between the various body proximate components and dry matter content were examined for five species of fishes, representing anadromous, marine and freshwater species: chum salmon Oncorhynchus keta, Chinook salmon Oncorhynchus tshawytscha, brook trout Salvelinus fontinalis, bluefish Pomatomus saltatrix and striped bass Morone saxatilis. The dry matter content or per cent dry mass of these fishes can be used to reliably predict the per cent composition of the other components. Therefore, with validation it is possible to estimate fat, protein and ash content of fishes from per cent dry mass information, reducing the need for costly and time-consuming laboratory proximate analysis. This approach coupled with new methods of non-lethal estimation of per cent dry mass, such as from bioelectrical impedance analysis, can provide non-destructive measurements of proximate composition of fishes. ?? 2008 The Authors.
Hartman, K.J.; Margraf, F.J.
Chiral spin torque arising from proximity-induced magnetization
NASA Astrophysics Data System (ADS)
Domain walls can be driven by current at very high speeds in nanowires formed from ultra-thin, perpendicularly magnetized cobalt layers and cobalt/nickel multilayers deposited on platinum underlayers due to a chiral spin torque. An important feature of this torque is a magnetic chiral exchange field that each domain wall senses and that can be measured by the applied magnetic field amplitude along the nanowire where the domain walls stop moving irrespective of the magnitude of the current. Here we show that this torque is manifested when the magnetic layer is interfaced with metals that display a large proximity-induced magnetization, including iridium, palladium and platinum but not gold. A correlation between the strength of the chiral spin torque and the proximity-induced magnetic moment is demonstrated by interface engineering using atomically thin dusting layers. High domain velocities are found where there are large proximity-induced magnetizations in the interfaced metal layers.
Ryu, Kwang-Su; Yang, See-Hun; Thomas, Luc; Parkin, Stuart S. P.
DNA replication-dependent induction of gene proximity by androgen.
The male hormone androgen, working through the androgen receptor (AR), plays a major role in physiological process and disease development. Previous studies of AR mainly focus on its transcriptional activity. Here, we found that androgen-induced TMPRSS2 and ERG gene proximity is mediated by AR control of DNA replication rather than gene transcription. We demonstrate that, in both AR transactivation-positive and -negative prostate cells, androgen regulates DNA replication and androgen-induced gene proximity relies on both DNA replication-licensing and actual DNA replication activity. Androgen stimulation advances DNA replication timing of certain genomic regions, which may potentially increase gene proximity through sharing the same replication factory at a similar time. Therefore, we have revealed novel mechanisms of AR biological function, which will stimulate new research directions. PMID:25281662
Coll-Bastus, Nuria; Mao, Xueying; Young, Bryan D; Sheer, Denise; Lu, Yong-Jie
Chiral spin torque arising from proximity-induced magnetization.
Domain walls can be driven by current at very high speeds in nanowires formed from ultra-thin, perpendicularly magnetized cobalt layers and cobalt/nickel multilayers deposited on platinum underlayers due to a chiral spin torque. An important feature of this torque is a magnetic chiral exchange field that each domain wall senses and that can be measured by the applied magnetic field amplitude along the nanowire where the domain walls stop moving irrespective of the magnitude of the current. Here we show that this torque is manifested when the magnetic layer is interfaced with metals that display a large proximity-induced magnetization, including iridium, palladium and platinum but not gold. A correlation between the strength of the chiral spin torque and the proximity-induced magnetic moment is demonstrated by interface engineering using atomically thin dusting layers. High domain velocities are found where there are large proximity-induced magnetizations in the interfaced metal layers. PMID:24852680
Ryu, Kwang-Su; Yang, See-Hun; Thomas, Luc; Parkin, Stuart S P
A Combined Method to Compute the Proximities of Asteroids
NASA Astrophysics Data System (ADS)
We describe a simple and efficient numerical-analytical method to find all of the proximities and critical points of the distance function in the case of two elliptical orbits with a common focus. Our method is based on the solutions of Simovljevi?'s (1974) graphical method and on the transcendent equations developed by Lazovi? (1993). The method is tested on 2 997 576 pairs of asteroid orbits and compared with the algebraic and polynomial solutions of Gronchi (2005). The model with four proximities was obtained by Gronchi (2002) only by applying the method of random samples, i.e., after many simulations and trials with various values of elliptical elements. We found real pairs with four proximities.
Ŗegan, S.; Milisavljevi?, S.; Mar?eta, D.
[Ca2+]i rises via G protein during regulatory volume decrease in rabbit proximal tubule cells.
Although animal cells swell in hypotonic medium, their volume is subsequently regulated by a net loss of KCl via Ca2(+)-dependent channels. A rise in intracellular free calcium ([Ca2+]i) thus appears to be an initial event in the adaptation of external tonicity, although details of this mechanism are not known. To investigate cell volume regulation, we measured [Ca2+]i (by use of fura-2) and cell diameters in single cells of cultured renal proximal convoluted tubule. We found that a rapid rise in [Ca2+]i occurred after cells were exposed to hypotonic solution (250 mosM) from 95.8 +/- 3.8 to 468.2 +/- 24 nM (n = 16). The rise in [Ca2+]i was not observed in cells exposed to Ca2(+)-free medium, and exposure to isotonic high-K or low-Na medium did not elicit a rise in [Ca2+]i, suggesting that this rise was a result of Ca2+ influx and not via voltage-dependent Ca2+ influx or decrease of Ca2+ efflux via Na(+)-Ca2+ pump. Pretreatment of cells with pertussis toxin dose dependently blocked the rise in [Ca2+]i. The hypotonic solution enhanced accumulations of inositol tris- and tetra-phosphate after a 1-min exposure. Studies that measured cell diameters suggest that recovery of cell volume may include the rise in [Ca2+]i. These data suggest that the regulatory volume decrease of proximal tubule cells involves a pertussis toxin-sensitive guanine nucleotide binding protein-operated Ca2+ influx. PMID:2107759
Suzuki, M; Kawahara, K; Ogawa, A; Morita, T; Kawaguchi, Y; Kurihara, S; Sakai, O
Intracellular chloride activity of rabbit proximal straight tubule perfused in vitro.
To examine the cellular mechanism of Cl- transport in the proximal tubule, cell Cl- activity (aiCl) was measured with double-barreled Cl(-)-selective microelectrodes in the rabbit proximal straight tubules (PST) perfused in vitro. When tubules were perfused and bathed with ultrafiltrate-like solution, aiCl (corrected for the interference from undetermined intracellular anions, 4.2 mM) was 17.8 +/- 0.5 mM (n = 90), and this value was 1.3 times higher than that predicted from passive distribution (basolateral membrane potential, Vbl = -51.9 +/- 0.8 mV). Reducing either luminal or bath Cl- indicated that the basolateral membrane plays a more important role as a determinant of aiCl. aiCl reduction rates induced by luminal Cl- removal was inhibited by 75% by 1 mM SITS added to the lumen but was not inhibited by furosemide (0.1 mM). Application of SITS in the lumen in the control condition, however, did not change aiCl appreciably. Reducing the luminal HCO3- from 25 to 5 mM did not significantly change aiCl or Vbl. Replacing luminal Na+ with choline decreased aiCl but these effects were still present when luminal Cl- was absent. We conclude that in the rabbit PST: 1) Cl- is taken up into the cell against the electrochemical gradient, 2) the basolateral membrane plays a more important role in the regulation of aiCl, and 3) luminal Cl- transport is SITS sensitive and Na+ independent. PMID:3394812
Ishibashi, K; Sasaki, S; Yoshiyama, N
Evolution and proximate expression of human paternal investment.
In more than 95% of mammalian species, males provide little direct investment in the well-being of their offspring. Humans are one notable exception to this pattern and, to date, the factors that contributed to the evolution and the proximate expression of human paternal care are unexplained (T. H. Clutton-Brock, 1989). The nature, extent, and influence of human paternal investment on the physical and social well-being of children are reviewed in light of the social and ecological factors that are associated with paternal investment in other species. On the basis of this review, discussion of the evolution and proximate expression of human paternal investment is provided. PMID:10668350
Geary, D C
Theory of Josephson tunneling into a proximity system
The properties of a Josephson function containing a proximity system are discussed. The value of the maximum dc Josephson current I/sub M/(T) depends strongly on the parameters of the proximity system. If N is a semiconducting film, the value of I/sub M/ may be affected by incident radiation. If N is a size-quantizing semimetal film, I/sub M/ becomes an oscillating function of the thickness L/sub N/. The weak link can be formed by the inversion layer and I/sub M/ can be controlled by the applied field.
Kresin, V.Z.
Ectrodactyly and proximal/intermediate interstitial deletion 7q
We report on an individual with severe mental retardation, seizures, microcephaly, unusual face, scoliosis, and cleft feet and cleft right hand. The chromosomal study showed a proximal interstitial deletion 7q (q11.23q22). From our review of the literature, 11 patients have been reported with ectrodactyly (split hand/split foot malformation) and proximal/intermediate interstitial deletions or rearrangements of 7q. The critical segment for ectrodactyly seems to be located between 7q21.2 and 7q22.1. This malformation is present in 41% of the patients whose deletion involves the critical segment. 37 refs., 3 figs., 1 tab.
McElveen, C.; Carvajal, M.V.; Moscatello, D. [Louisiana State Univ. Medical Center, New Orleans, LA (United States)] [and others
Technique, indications, and results of proximal medial gastrocnemius lengthening.
Gastrocnemius proximal lengthening was first performed to correct spasticity in children, and was adapted for the patient with no neuromuscular condition in the late 1990s. Since then, the proximal gastrocnemius release has become less invasive and has evolved to include only the fascia overlying the medial head of the gastrocnemius muscle. The indications for performing this procedure are a clinically demonstrable gastrocnemius contracture that influences a variety of clinical conditions in the forefoot, hindfoot, and ankle. It is a safe and easy procedure that can be performed bilaterally simultaneously, and does not require immobilization of the ankle after surgery. PMID:25456723
Barouk, Pierre
Inverse proximity effect in superconductor-ferromagnet bilayer structures.
Measurements of the polar Kerr effect using a zero-area-loop Sagnac magnetometer on Pb/Ni and Al/(Co-Pd) proximity-effect bilayers show unambiguous evidence for the "inverse proximity effect," in which the ferromagnet induces a finite magnetization in the superconducting layer. To avoid probing the magnetic effects in the ferromagnet, the superconducting layer was prepared much thicker than the light's optical-penetration depth. The sign and size of the effect, as well as its temperature dependence agree with recent predictions by Bergeret et al. [Phys. Rev. B 69, 174504 (2004)]10.1103/PhysRevB.69.174504. PMID:19257779
Xia, Jing; Shelukhin, V; Karpovski, M; Kapitulnik, A; Palevski, A
The model of sodium and chloride transport proposed for the colon is based on studies performed in the distal segment and tacitly assumes that ion transport is similar throughout the colon. In rat distal colon, neutral sodium-chloride absorption accounts for the major fraction of overall sodium absorption and aldosterone stimulates electrogenic, amiloride-sensitive sodium absorption. Since we have demonstrated qualitative differences in potassium transport in proximal and distal segments of rat colon, unidirectional 22Na and 36Cl fluxes were performed under short-circuit conditions across isolated proximal colon of control and sodium-depleted rats with secondary hyperaldosteronism. In the control group, net sodium absorption (JNanet) (7.4 +/- 0.5 mu eq/h . cm2) was greater than Isc (1.4 +/- 0.1 mu eq/h . cm2), and JClnet was 0 in Ringer solution. Residual flux (JR) was -5.2 +/- 0.5 mu eq/h . cm2 consistent with hydrogen ion secretion suggesting that neutral sodium absorption may represent sodium-hydrogen exchange. 1 mM mucosal amiloride, which inhibits sodium-hydrogen exchange in other epithelia, produced comparable decreases in JNanet and JR (4.1 +/- 0.6 and 3.2 +/- 0.6 mu eq/h . cm2, respectively) without a parallel fall in Isc. Sodium depletion stimulated JNanet, JClnet, and Isc by 7.0 +/- 1.4, 6.3 +/- 1.9, and 0.8 +/- 0.2 mu eq/h . cm2, respectively, and 1 mM amiloride markedly inhibited JNanet and JClnet by 6.0 +/- 1.1 and 4.0 +/- 1.6 mu eq/h . cm2, respectively, with only a minimal reduction in Isc. Conclusions: the predominant neutral sodium-absorptive mechanism in proximal colon is sodium-hydrogen exchange. Sodium depletion stimulates electroneutral chloride-dependent sodium absorption (most likely as a result of increasing sodium-hydrogen and chloride-bicarbonate exchanges), not electrogenic chloride-independent sodium transport. The model of ion transport in the proximal colon is distinct from that of the distal colon. PMID:2418060
Foster, E S; Budinger, M E; Hayslett, J P; Binder, H J
NASA Astrophysics Data System (ADS)
The Proximity Operations Nano-Satellite Flight Demonstration (PONSFD) program is to demonstrate rendezvous proximity operations (RPO), formation flying, and docking with a pair of 3U CubeSats. The program is sponsored by NASA Ames via the Office of the Chief Technologist (OCT) in support of its Small Spacecraft Technology Program (SSTP). The goal of the mission is to demonstrate complex RPO and docking operations with a pair of low-cost 3U CubeSat satellites using passive navigation sensors. The program encompasses the entire system evolution including system design, acquisition, satellite construction, launch, mission operations, and final disposal. The satellite is scheduled for launch in Fall 2015 with a 1-year mission lifetime. This paper provides a brief mission overview but will then focus on the current design and driving trade study results for the RPO mission specific processor and relevant ground software. The current design involves multiple on-board processors, each specifically tasked with providing mission critical capabilities. These capabilities range from attitude determination and control to image processing. The RPO system processor is responsible for absolute and relative navigation, maneuver planning, attitude commanding, and abort monitoring for mission safety. A low power processor running a Linux operating system has been selected for implementation. Navigation is one of the RPO processor's key tasks. This entails processing data obtained from the on-board GPS unit as well as the on-board imaging sensors. To do this, Kalman filters will be hosted on the processor to ingest and process measurements for maintenance of position and velocity estimates with associated uncertainties. While each satellite carries a GPS unit, it will be used sparsely to conserve power. As such, absolute navigation will mainly consist of propagating past known states, and relative navigation will be considered to be of greater importance. For relative observations, each spacecraft hosts 3 electro-optical sensors dedicated to imaging the companion satellite. The image processor will analyze the images to obtain estimates for range, bearing, and pose, with associated rates and uncertainties. These observations will be fed to the RPO processor's relative Kalman filter to perform relative navigation updates. This paper includes estimates for expected navigation accuracies for both absolute and relative position and velocity. Another key task for the RPO processor is maneuver planning. This includes automation to plan maneuvers to achieve a desired formation configuration or trajectory (including docking), as well as automation to safely react to potentially dangerous situations. This will allow each spacecraft to autonomously plan fuel-efficient maneuvers to achieve a desired trajectory as well as compute adjustment maneuvers to correct for thrusting errors. This paper discusses results from a trade study that has been conducted to examine maneuver targeting algorithms required on-board the spacecraft. Ground software will also work in conjunction with the on-board software to validate and approve maneuvers as necessary.
Griesbach, J.; Westphal, J. J.; Roscoe, C.; Hawes, D. R.; Carrico, J. P.
Renal Phenotype in Lowe Syndrome: A Selective Proximal Tubular Dysfunction
Background and objectives: Lowe syndrome is defined by congenital cataracts, mental retardation, and proximal tubulopathy and is due to mutations in OCRL. Recently, mutations in OCRL were found to underlie some patients with Dent disease, characterized by low molecular weight proteinuria, hypercalciuria, and nephrocalcinosis. This phenotypic heterogeneity is poorly understood. Design, setting, participants, & measurements: The renal phenotype of 16 patients with Lowe syndrome (10.9 ▒ 7.0 yr) under care of the authors was characterized to define overlap of symptoms with Dent disease and infer clues about OCRL function. Medical charts of patients were reviewed for data regarding glomerular filtration rate and markers of proximal tubular function. Results: All patients had low molecular weight proteinuria and albuminuria. Lysosomal enzymuria was elevated in all 11 patients assessed. Fifteen patients had hypercalciuria, and 14 aminoaciduria. Seven patients required bicarbonate and three required phosphate replacement; all others maintained normal serum values without supplementation. None of the patients had detectable glycosuria, and none had clinically overt rickets. GFR was mildly to moderately impaired and highly variable, with a trend of deterioration with age. Conclusions: Patients with Lowe syndrome do not have renal Fanconi syndrome but a selective proximal tubulopathy, variable in extent and dominated by low molecular weight proteinuria and hypercalciuria, the classical features of Dent disease. These findings suggest that OCRL and ClC-5, the chloride channel mutated in Dent disease, are involved in similar reabsorption pathways in the proximal tubule. PMID:18480301
Bockenhauer, Detlef; Bokenkamp, Arend; van't Hoff, William; Levtchenko, Elena; Kist-van Holthe, Joana E.; Tasic, Velibor; Ludwig, Michael
Proximal-like contraction methods for monotone variational ...
ćDepartment of Mathematics, Hong Kong Baptist University, Hong Kong, China ... To study and pair various APPAs for different types of variational inequalities, we .... extended version of the primary method according to the quadruplet; and compare the proximal ...... Singapore, 2008. http://www.math.nus.edu.sg/ matsundf/.
Distance Based Indexing for String Proximity Search S. Cenk Sahinalp
operations to transform one string into the other. Examples include the Levenshtein edit distance. Character edit distances, such as the (unweighted) Levenshtein edit distance [34] or its weighted versionDistance Based Indexing for String Proximity Search S. Cenk Sahinalp ┬ó┬Ī┬ż┬Ż , Murat Tasan ┬Ż┬ź , Jai
Interlanguage Pragmatics in the Zone of Proximal Development
ERIC Educational Resources Information Center
Vygotsky's zone of proximal development (ZPD) has been fruitfully applied in L2 research that examines second and foreign language learning. This paper considers the applicability of the ZPD to interlanguage pragmatics instruction and research. First, the ZPD is defined [Vygotsky, L.S., 1978. Mind in Society: The Development of Higherģ
Ohta, Amy Snyder
Proximate and Ultimate Mechanisms of Spiny Lobster Gregariousness
Abstract Proximate and Ultimate Mechanisms of Spiny Lobster Gregariousness Ken Sercy and Michael show clear differences in spiny lobster gregariousness. Panulirus argus is usually found sharing variation in lobster distribution and fitness. Spiny lobsters are a convenient model system for studying
Childress, Michael J.
Constrained spectral clustering under a local proximity structure assumption
NASA Technical Reports Server (NTRS)
This work focuses on incorporating pairwise constraints into a spectral clustering algorithm. A new constrained spectral clustering method is proposed, as well as an active constraint acquisition technique and a heuristic for parameter selection. We demonstrate that our constrained spectral clustering method, CSC, works well when the data exhibits what we term local proximity structure.
Wagstaff, Kiri; Xu, Qianjun; des Jardins, Marie
Efficient Node Overlap Removal Using a Proximity Stress Model
Efficient Node Overlap Removal Using a Proximity Stress Model Emden R. Gansner and Yifan Hu AT of the initial layout or as a post-processing step. The core problem is to avoid overlaps while retaining overlap removal algorithm that does well by these measures. 1 Introduction Most existing symmetric graph
Hu, Yifan
Modelling Primate Social Order: Ultimate and Proximate Explanations
Modelling Primate Social Order: Ultimate and Proximate Explanations Hagen Lehmann and Joanna email@example.com, email@example.com Abstract. For many species of primates, arguably including humans, social be understanding the bases of our social interaction. For many primate species social be- haviour has been
Bryson, Joanna J.
Proximal-ACCPM: a versatile oracle based optimization method
Oct 26, 2004 ... 1An optimality problem can be cast in the format of a pure feasibility ... sentative of large-scale continuous optimization. ... Our last application deals with air quality control in urban regions .... The stopping criterion is triggered by the proximity measure. ...... linear function of the economic activity level, say.
Proximate Causes of Two Types of AB Questions
Nervous system has fast response but shorter duration Endocrine system has slower response but longer Proximate Factors Hormones Nervous system Genes Environment Parasites/symbionts #12;3 Hormones & Behavior Hormones are chemical signaling molecules that travel through blood (or other fluid) Come from: Endocrine
Brown, Christopher A.
The impact of DHT routing geometry on resilience and proximity
The various proposed DHT routing algorithms embody several different underlying routing geometries. These geometries include hypercubes, rings, tree-like structures, and butterfly networks. In this paper we focus on how these basic geometric approaches affect the resilience and proximity properties of DHTs. One factor that distinguishes these geometries is the degree of flexibility they provide in the selection of neighbors and
K. Gummadi; Ramakrishna Gummadi; Steven D. Gribble; Sylvia Ratnasamy; Scott Shenker; Ion Stoica
Proximity and specificity of planning: A position paper
The results of a recent set of studies have generated some confusion about the parameters of planning. Several findings seem to suggest that relatively proximal and specific planning improves self-regulation, whereas other research seems to favor more distal and less specific planning. The relevant concepts are defined and the literature is reviewed in an attempt to begin resolving these apparent
Daniel S. Kirschenbaum
Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers
Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers David L. Carr are significantly associated at the global and regional scales, evidence for population links to deforestation of thought on population┬Łenvironment theories relevant to deforestation in tropical agricultural frontiers
Lopez-Carr, David
Optimizing Design of Smaller Antennas for Proximity Transponders
New person-related applications now require to produce 13.56 MHz SmartCard transponders supporting the ISO\\/IEC14443 Proximity Standard in smaller sizes. We describe antenna design methods in combination with transponder system properties, to show how to efficiently combine established chip platforms with smaller antenna form factors.
Michael Gebhart; R. Szoncso
Residential proximity to major roads and obstetrical complications.
Exposure to air pollution is linked with an increased risk of preterm births. To provide further evidence on this relationship, we evaluated the association between proximity to major roads-as an index for air pollution exposure-and various obstetrical complications. Data were extracted from a database maintained by the perinatal hospital in Shizuoka, Japan. We restricted the analysis to mothers with singleton pregnancies of more than 22weeks of gestation from 1997 to 2012 (n=19,077). Using the geocoded residential information, each mother was assigned proximity to major roads. We then estimated multivariate adjusted odds ratios and their 95% confidence intervals (CIs) for the effects of proximity to major roads on various obstetrical complications (preeclampsia, gestational diabetes mellitus, placenta abruption, placenta previa, preterm premature rupture of membrane (pPROM), preterm labor, and preterm births). We found positive associations of proximity to major roads with preeclampsia and pPROM. Living within 200m increased the odds of preeclampsia by 1.3 times (95% CI, 1.0-1.8) and pPROM by 1.6 times (95% CI, 1.1-2.2). Furthermore, living within 200m increased the odds of preterm births by 1.4 fold (95% CI, 1.2-1.7). Exposure to traffic-related air pollution increased the risk of preeclampsia and pPROM in this study. We propose a mechanism responsible for the association between air pollution and preterm births. PMID:25478655
Yorifuji, Takashi; Naruse, Hiroo; Kashima, Saori; Murakoshi, Takeshi; Doi, Hiroyuki
Sharpening a Tool for Teaching: The Zone of Proximal Development
ERIC Educational Resources Information Center
Vygotsky's Zone of Proximal Development (ZPD) provides an important understanding of learning, but its implications for teachers are often unclear or limited and could be further explored. We use conceptual analysis to sharpen the ZPD as a teaching tool, illustrated with examples from teaching critical thinking in zoology. Our conclusions areģ
Wass, Rob; Golding, Clinton
Scaffolding Critical Thinking in the Zone of Proximal Development
ERIC Educational Resources Information Center
This paper explores student experiences of learning to think critically. Twenty-six zoology undergraduates took part in the study for three years of their degree at the University of Otago, New Zealand. Vygotsky's developmental model of the Zone of Proximal Development (ZPD) provided a framework as we examined how critical thinking was developed.ģ
Wass, Rob; Harland, Tony; Mercer, Alison
Technique for temperature compensation of eddy-current proximity probes
NASA Technical Reports Server (NTRS)
Eddy-current proximity probes are used in turbomachinery evaluation testing and operation to measure distances, primarily vibration, deflection, or displacment of shafts, bearings and seals. Measurements of steady-state conditions made with standard eddy-current proximity probes are susceptible to error caused by temperature variations during normal operation of the component under investigation. Errors resulting from temperature effects for the specific probes used in this study were approximately 1.016 x 10 to the -3 mm/deg C over the temperature range of -252 to 100 C. This report examines temperature caused changes on the eddy-current proximity probe measurement system, establishes their origin, and discusses what may be done to minimize their effect on the output signal. In addition, recommendations are made for the installation and operation of the electronic components associated with an eddy-current proximity probe. Several techniques are described that provide active on-line error compensation for over 95 percent of the temperature effects.
Masters, Robert M.
Proximal dup(10q): Case report and literature review
We report a case of a proximal dir dup(10q) in a female with multiple congenital anomalies. During infancy she was noted to gave growth retardation, microcephaly, microphthalmia, coloboma, a long, beaked nose, posteriorly rotated ears with simple helices, full bowed lips, widely-spaced nipples, broad first toes, hypermobile and proximally placed thumbs, a heart murmur, PDA, and coarctation of the aorta. Additional findings at age 13 included a full columella, short philtrum, thin limbs, bilateral blindness, and mental retardation, as well as continued growth retardation. Her medical history included precocious puberty at age 8 and a diagnosis of hyperactivity. Using FISH with multiple probes combined with GTG-banding, the aberrant chromosome was determined to be a dir dup(10)(q21{r_arrow}q22). Parental chromosomes were normal and the family history was unremarkable. The parental origin of the dir dup(10) is being assessed using DNA markers. Five similar cases of proximal dup(10q) have been reported previously. Consistent characteristics include low birth weight, developmental and psychomotor delay, growth retardation, and microcephaly. Also found in most cases were short prominent philtrum, bowed mouth, PDA, thin limbs, coloboma, micropthalmia, deep set eyes, and other ocular anomalies. Our case is unique in that she has a long, beaked nose, precocious puberty, and hyperactivity. Future studies such as this, using molecular cytogenetic techniques to better define the chromatin involved in proximal dup(10q), may lead to its recognition as a distinct clinical phenotype.
Barritt, J.A.; Teague, K.E.; Bodurtha, J.N. [Virginia Commonwealth Univ., Richmond, VA (United States)] [and others
An Extension of the Proximal Point Method for Quasiconvex ...
This class was introduced by Teboulle [29] in order to define entropy-like proximal maps;. 2 ... in location theory [17], control theory [9] and specially in economic theory [28]. ... The authors proved that the sequence stop in a finite number.
Proximal Point Method for Minimizing Quasiconvex Locally Lipschitz ...
tions, for example, in location theory [18] and specially in economic theory [36]. Further ... The authors proved that the sequence stops in a finite number ...... [26] Pan, S. H., and Chen, J. S., Entropy-Like Proximal Algorithms Based on a Second
Proximal tubule cells stimulated by lipopolysaccharideinhibit macrophage activation
Proximal tubule cells stimulated by lipopolysaccharide inhibit macrophage activation.BackgroundTubule cells can produce a variety of cytokines, extracellular matrix (ECM) components, and adhesion molecules in vitro and in vivo. It is generally assumed that stimulated tubule cells are proinflammatory and at least partially responsible for interstitial inflammation. However, the overall effect of tubular cells on interstitial cells is unknown. In this
Mobile Sensemaking: Exploring Proximity and Mobile Applications in the Classroom
Mobile Sensemaking: Exploring Proximity and Mobile Applications in the Classroom Gustavo Zurita (Management and Information Systems Department, Faculty of Economy and Business University of Chile, Santiago, University of Chile, Santiago de Chile Chile email@example.com) Felipe Baytelman (Management
Antunes, Pedro
SENSITIVITY AND REGIONALLY PROXIMAL RELATION IN MINIMAL SYSTEMS SONG SHAO, XIANGDONG YE AND RUIFENG ZHANG Abstract. A topological dynamical system is n-sensitive, if there is a positive constant at least for a same moment. The properties of n-sensitivity in minimal systems are investigated. It turns
Shao, Song
On the Surprising Salience of Curvature in Grouping by Proximity
ERIC Educational Resources Information Center
The authors conducted 3 experiments to explore the roles of curvature, density, and relative proximity in the perceptual organization of ambiguous dot patterns. To this end, they developed a new family of regular dot patterns that tend to be perceptually grouped into parallel contours, dot-sampled structured grids (DSGs). DSGs are similar to theģ
Strother, Lars; Kubovy, Michael
Proximity to coast is linked to climate change belief.
Psychologists have examined the many psychological barriers to both climate change belief and concern. One barrier is the belief that climate change is too uncertain, and likely to happen in distant places and times, to people unlike oneself. Related to this perceived psychological distance of climate change, studies have shown that direct experience of the effects of climate change increases climate change concern. The present study examined the relationship between physical proximity to the coastline and climate change belief, as proximity may be related to experiencing or anticipating the effects of climate change such as sea-level rise. We show, in a national probability sample of 5,815 New Zealanders, that people living in closer proximity to the shoreline expressed greater belief that climate change is real and greater support for government regulation of carbon emissions. This proximity effect held when adjusting for height above sea level and regional poverty. The model also included individual differences in respondents' sex, age, education, political orientation, and wealth. The results indicate that physical place plays a role in the psychological acceptance of climate change, perhaps because the effects of climate change become more concrete and local. PMID:25047568
Milfont, Taciano L; Evans, Laurel; Sibley, Chris G; Ries, Jan; Cunningham, Andrew
Proximity to Coast Is Linked to Climate Change Belief
Psychologists have examined the many psychological barriers to both climate change belief and concern. One barrier is the belief that climate change is too uncertain, and likely to happen in distant places and times, to people unlike oneself. Related to this perceived psychological distance of climate change, studies have shown that direct experience of the effects of climate change increases climate change concern. The present study examined the relationship between physical proximity to the coastline and climate change belief, as proximity may be related to experiencing or anticipating the effects of climate change such as sea-level rise. We show, in a national probability sample of 5,815 New Zealanders, that people living in closer proximity to the shoreline expressed greater belief that climate change is real and greater support for government regulation of carbon emissions. This proximity effect held when adjusting for height above sea level and regional poverty. The model also included individual differences in respondents' sex, age, education, political orientation, and wealth. The results indicate that physical place plays a role in the psychological acceptance of climate change, perhaps because the effects of climate change become more concrete and local. PMID:25047568
Milfont, Taciano L.; Evans, Laurel; Sibley, Chris G.; Ries, Jan; Cunningham, Andrew
Constructing Proximity: Relating to Readers in Popular and Professional Science
ERIC Educational Resources Information Center
The view of academic discourse as a rhetorical activity involving interactions between writers and readers is now central to most perspectives on EAP, but these interactions are conducted differently in different disciplinary and generic contexts. In this paper I use the term "proximity" to refer to a writer's control of those rhetorical featuresģ
Hyland, Ken
Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.
Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N=31), Plio-Pleistocene fossil hominins (N=8), Pan troglodytes troglodytes (N=13), and Pan paniscus (N=3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out. PMID:22609080
Bleuze, M
OVERVIEW OF ARENA AND SOUTHWEST ENTRANCE TERRACE SHOWING THE PROXIMITY OF THE UNDERGROUND SPLINTERPROOF SHELTER, FACILITY S897 (CENTER) TO THE ARENA. VIEW FACING NORTHEAST - U.S. Naval Base, Pearl Harbor, Bloch Recreation Center & Arena, Between Center Drive & North Road near Nimitz Gate, Pearl City, Honolulu County, HI
De novo partial trisomy 15q (proximal type).
This report describes a retarded girl with strabismus, high arched palate, antimongoloid slant, low set ears, hearing loss, micrognathia, short neck, and an anteriorly displaced anus. She was found to have a de novo partial trisomy of the proximal part of the long arm of chromosome 15. Images PMID:2966860
Herweijer, T J; Oorthuys, J W; Leschot, N J
The combination of vision and touch depends on spatial proximity
The combination of vision and touch depends on spatial proximity Vision Science Program, School combines visual and haptic information about object properties such that the combined estimate is more precise than with vision or haptics alone. We examined how the system determines when to combine
Burge, Johannes
Stationary Properties of High Critical Temperature Proximity Effect Josephson Junctions
NASA Technical Reports Server (NTRS)
The data is reviewed about superconductor-normal-superconductor (SNS) devices, and the conclusion is drawn that there is no conventional proximity effect in the majority of reported high Tc devices. The present experimental and theoretical understanding of SNS junctions is discussed as well as implications for future research.
Delin, K. A.; Kleinsasser, A. W.
Compression or tension? The stress distribution in the proximal femur
Background Questions regarding the distribution of stress in the proximal human femur have never been adequately resolved. Traditionally, by considering the femur in isolation, it has been believed that the effect of body weight on the projecting neck and head places the superior aspect of the neck in tension. A minority view has proposed that this region is in compression because of muscular forces pulling the femur into the pelvis. Little has been done to study stress distributions in the proximal femur. We hypothesise that under physiological loading the majority of the proximal femur is in compression and that the internal trabecular structure functions as an arch, transferring compressive stresses to the femoral shaft. Methods To demonstrate the principle, we have developed a 2D finite element model of the femur in which body weight, a representation of the pelvis, and ligamentous forces were included. The regions of higher trabecular bone density in the proximal femur (the principal trabecular systems) were assigned a higher modulus than the surrounding trabecular bone. Two-legged and one-legged stances, the latter including an abductor force, were investigated. Results The inclusion of ligamentous forces in two-legged stance generated compressive stresses in the proximal femur. The increased modulus in areas of greater structural density focuses the stresses through the arch-like internal structure. Including an abductor muscle force in simulated one-legged stance also produced compression, but with a different distribution. Conclusion This 2D model shows, in principle, that including ligamentous and muscular forces has the effect of generating compressive stresses across most of the proximal femur. The arch-like trabecular structure transmits the compressive loads to the shaft. The greater strength of bone in compression than in tension is then used to advantage. These results support the hypothesis presented. If correct, a better understanding of the stress distribution in the proximal femur may lead to improvements in prosthetic devices and an appreciation of the effects of various surgical procedures affecting load transmission across the hip. PMID:16504005
Rudman, KE; Aspden, RM; Meakin, JR
Proximal Tumors Are Associated with Greater Mortality in Colon Cancer
ABSTRACT BACKGROUND Colon cancer is the third leading cause of death from cancer in the United States. Recent studies report on increasing proportions of proximal cancers. The etiology behind this epidemiological trend is unclear, and its implication on survival outcomes is unknown. Further analysis of the impact of anatomic site of disease among a large multiethnic population will help facilitate research and education to improve colon cancer screening and treatment. OBJECTIVE To investigate the association between proximal tumor location and survival in patients with colon cancer. DESIGN AND PARTICIPANTS A large retrospective cohort study in the US utilizing the Surveillance, Epidemiology, and End Results (SEER) cancer registry analyzed survival outcomes of patients with colon cancer. Multivariable logistic regression analyses investigated sex-specific, race/ethnicity-specific, and anatomic site-specific disparities in survival. MAIN MEASURES Five-year survival outcomes from colon cancer. RESULTS Our study demonstrated significant disparities in survival by sex, race/ethnicity, and anatomic site. Across all time periods and among most cohorts, patients with proximal cancers had significantly worse survival outcomes. When compared to distal cancers, patients with proximal cancers were 13% less likely to survive 5Āyears (OR 0.87; 95% CI, 0.82¢0.91). When compared to non-Hispanic whites, blacks were 30% less likely to survive 5Āyears (OR 0.70; 95% CI, 0.68¢0.73). Stage-specific multivariable regression analysis of localized cancers demonstrated similar findings. CONCLUSIONS Significant race-specific, sex-specific, and anatomic site-specific disparities in colon cancer survival exist. Proximal cancers are associated with worse survival odds. These disparities may reflect differences in the genotype and phenotype of colon cancer among these groups. A modified risk assessment tool that incorporates these variations may be more effective in the early detection and treatment of colon cancer. PMID:20652758
Induction of hypertrophy in cultured proximal tubule cells by extracellular NH4Cl.
Ammonia production increases in several models of renal hypertrophy in vivo. The present study was designed to determine whether ammonia can directly modulate the growth of renal cells in the absence of a change in extracellular acidity. In serum-free media NH4Cl (0-20 mM) caused JTC cells and a primary culture of rabbit proximal tubule cells to hypertrophy (increase in cell protein content) in a dose-dependent fashion without a change in DNA synthesis. Studies in JTC cells revealed that the cell protein content increased as a result of both an increase in protein synthesis and a decrease in protein degradation. Total cell RNA content and ribosome number increased after NH4Cl exposure and the cell content of the lysosomal enzymes cathepsin B and L decreased. Inhibition of the Na+/H+ antiporter with amiloride did not prevent the hypertrophic response induced by NH4Cl. The results indicate that ammonia is an important modulator of renal cell growth and that hypertrophy can occur in the absence of functioning Na+/H+ antiport activity. Images PMID:2480366
Golchini, K; Norman, J; Bohman, R; Kurtz, I
Models for coupling of salt and water transport; Proximal tubular reabsorption in Necturus kidney
Models for coupling of salt and water transport are developed with two important assumptions appropriate for leaky epithelia. (a) The tight junction is permeable to both sale and water. (b) Active Na transport into the lateral speces is assumed to occur uniformly along the length of the channel. The proposed models deal specifically with the intraepithelial mechanism of proximal tubular resbsorption in the Necturus kidney although they have implications for epithelial transport in the gallbladder and small intestine as well. The first model (continuous version) is similar to the standing gradient model devised by Diamond and Bossert but used different boundary conditions. In contrast to Diamond and Bossert's model, the predicted concentration profiles are relatively flat with no sizable gradients along the interspace. The second model (compartment version) expands Curran's model of epithelial salt and water transport by including additional compartments and considering both electrical and chemical driving forces for individual Na and Cl ions as well as hydraulic and osmotic driving forces for water. In both models, ion and water fluxes are investigated as a function of the transport parameters. The behavior of the models is consistent with previously suggested mechanisms for the control of net transport, particularly during saline diuresis. Under all conditions the predicted ratio of net solute to solvent flux, or emergent concentration, deviates from exact isotonicity (except when the basement membrane has an appreciable salt reflection coefficient). However, the degree of hypertonicity may be small enough to be experimentally indistinguishable from isotonic transport. PMID:1104761
Sackin, H; Boulpaep, EL
The dopaminergic and renin-angiotensin systems interact to regulate blood pressure. Disruption of the D4 dopamine receptor gene in mice produces hypertension that is associated with increased renal angiotensin type 1 (AT1) receptor expression. We hypothesize that the D4 receptor can inhibit AT1 receptor expression and function in renal proximal tubule cells from Wistar-Kyoto (WKY) rats, but the D4 receptor regulation of AT1 receptor is aberrant in renal proximal tubule cells from spontaneously hypertensive rats (SHRs). The D4 receptor agonist, PD168077, decreased AT1 receptor protein expression in a time- and concentration-dependent manner in WKY cells. By contrast, in SHR cells, PD168077 increased AT1 receptor protein expression. The inhibitory effect of D4 receptor on AT1 receptor expression in WKY cells was blocked by a calcium channel blocker, nicardipine, or calcium-free medium, indicating that calcium is involved in the D4 receptor-mediated signaling pathway. Angiotensin II increased Na(+)-K(+) ATPase activity in WKY cells. Pretreatment with PD168077 decreased the stimulatory effect of angiotensin II on Na(+)-K(+) ATPase activity in WKY cells. In SHR cells, the inhibitory effect of D4 receptor on angiotensin II-mediated stimulation of Na(+)-K(+) ATPase activity was aberrant; pretreatment with PD168077 augmented the stimulatory effect of AT1 receptor on Na(+)-K(+) ATPase activity in SHR cells. This was confirmed in vivo; pretreatment with PD128077 for 1 week augmented the antihypertensive and natriuretic effect of losartan in SHRs but not in WKY rats. We suggest that an aberrant interaction between D4 and AT1 receptors may play a role in the abnormal regulation of sodium excretion in hypertension. PMID:25368031
Chen, Ken; Deng, Kun; Wang, Xiaoyan; Wang, Zhen; Zheng, Shuo; Ren, Hongmei; He, Duofen; Han, Yu; Asico, Laureano D; Jose, Pedro A; Zeng, Chunyu
Proximate and landscape factors influence grassland bird distributions.
Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and landscape scales on grassland birds, a group of birds of high conservation concern, in the Sheyenne National Grassland in North Dakota, USA. The Grassland contains a diverse array of grassland and woodland habitats. We surveyed breeding birds on 2015 100 m long transect segments during 2002 and 2003. We modeled the occurrence of 19 species in relation to habitat features (percentages of grassland, woodland, shrubland, and wetland) within each 100-m segment and to tree cover within 200-1600 m of the segment. We used information-theoretic statistical methods to compare models and variables. At the proximate scales, tree cover was the most important variable, having negative influences on 13 species and positive influences on two species. In a comparison of multiple scales, models with only proximate variables were adequate for some species, but models combining proximate with landscape information were best for 17 of 19 species. Landscape-only models were rarely competitive. Combined models at the largest scales (800-1600 m) were best for 12 of 19 species. Seven species had best models including 1600-m landscapes plus proximate factors in at least one year. These were Wilson's Phalarope (Phalaropus tricolor), Sedge Wren (Cistothorus platensis), Field Sparrow (Spizella pusilla), Grasshopper Sparrow (Ammodramus savannarum), Bobolink (Dolychonix oryzivorus), Red-winged Blackbird (Agelaius phoeniceus), and Brown-headed Cowbird (Molothrus ater). These seven are small-bodied species; thus larger-bodied species do not necessarily respond most to the largest landscapes. Our findings suggest that birds respond to habitat features at a variety of scales. Models with only landscape-scale tree cover were rarely competitive, indicating that broad-scale modeling alone, such as that based solely on remotely sensed data, is likely to be inadequate in explaining species distributions. PMID:16827003
Cunningham, Mary Ann; Johnson, Douglas H
Proximal gastric vagotomy: a district general hospital experience.
A district general hospital experience with proximal gastric vagotomy over a nine-year period is reported. One hundred and eight patients undergoing the operation for chronic duodenal ulcer were assessed. The follow-up period was 1-9 years (mean 4 years and 7 months). The results were graded using a modification of the classification of Visick (1948). Over 85% of our patients were satisfied with their results. (Visick 1 and 2). Recurrent ulceration was noted in 3.9% of our series (4 cases). There were no deaths and few complications. The technique used by us is described briefly and the role of proximal gastric vagotomy in a district general hospital is discussed. PMID:6859783
Wood, J. J.; Ryan, J. M.; Anders, C. J.
Copper in silicon: Quantitative analysis of internal and proximity gettering
The behavior of copper in the presence of a proximity gettering mechanism and a standard internal gettering mechanism in silicon was studied. He implantation-induced cavities in the near surface region were used as a proximity gettering mechanism and oxygen precipitates in the bulk of the material provided internal gettering sites. Moderate levels of copper contamination were introduced by ion implantation such that the copper was not supersaturated during the anneals, thus providing realistic copper contamination/gettering conditions. Copper concentrations at cavities and internal gettering sites were quantitatively measured after the annealings. In this manner, the gettering effectiveness of cavities was measured when in direct competition with internal gettering sites. The cavities were found to be the dominant gettering mechanism with only a small amount of copper gettered at the internal gettering sites. These results reveal the benefits of a segregation-type gettering mechanism for typical contamination conditions.
McHugo, S.A. [Lawrence Berkeley National Lab., CA (United States); Flink, C.; Weber, E.R. [Univ. of California, Berkeley, CA (United States)] [and others
Office paper recycling: A function of container proximity
We investigated the effects of proximity of containers on pounds of office paper recycled and not recycled by 25 employees. During a memo and central container condition, one container for recyclable paper was provided; in a memo and local container condition, desktop recycling bins, announced by memo, were successively introduced across administrative, office, and instructional settings using a multiple baseline design. Only 28% of paper was recycled in the central container condition, but when recycling containers were placed in close proximity to participants, 85% to 94% of all recyclable paper was recycled. Follow-up assessments, conducted 1, 2, 3, and 7 months after all settings received local recycling containers, showed that 84% to 98% of paper was recycled. Providing desktop recycling containers was a cost-effective procedure with long-term maintenance and program survival. PMID:16795821
Brothers, Kevin J.; Krantz, Patricia J.; McClannahan, Lynn E.
Proximity effect enhancement induced by a superconducting anti-dot
NASA Astrophysics Data System (ADS)
In this work, we study the proximity and pinning effects of a rectangular superconducting anti-dot on the magnetization curve of a mesoscopic sample. We solve the nonlinear time-dependent Ginzburg-Landau equations for a superconducting rectangle in the presence of a magnetic field applied perpendicular to its surface. The pinning effects are determined by the number of vortices into the anti-dot. We calculate the order parameter, vorticity, magnetization and critical fields as a function of the external magnetic field. We found that the size and nature of the anti-dot strongly affect the magnetization of the sample. The results are discussed in framework of pinning and proximity effects in mesoscopic systems.
Higuera, Sindy J.; Joya, Miryam R.; Barba-Ortega, J.
Two patients with a complete proximal rupture of the hamstring.
Two men visited our Emergency Room because of a water-ski-accident. At physical examination, there was hematoma at the upper leg with loss of strength at extension of the hip and flexion of the knee. Both patients had a palpable gap just distal of the ischial tuberosity. Further imaging by sonography and MR-scan showed a rupture of the proximal hamstring tendon. Treatment was operative refixation of the hamstring tendons at the ischial tuberosity. After treatment consisted of brace for 4 weeks after operation. Both patients returned to their pre-operatively sports, though at a lower level. Surgical treatment of a complete proximal rupture of the hamstrings is recommended in case of sportive patients. PMID:19688217
Floor, Sebastiaan; van der Veen, Alex H; Devilee, Roger J
Upgrade of the proximity focusing RICH at Jlab
The Hall A RICH at Jefferson Lab is undergoing an upgrade to adapt to the higher momentum kinematics of the neutron spin structure Transversity experiments planned to run in 2008. The JLab RICH is a proximity focusing detector using liquid C6F14 as Cherenkov radiator, a thin layer of CsI as photon converter, evaporated on segmented pad panels of a proportional chamber. The original RICH had a superior hadron identification up to 2 GeV/c with pion/kaon rejection at the level of 1:1000 at ~ similar90% intrinsic efficiency. The upgrade will extend this performance above 2.4 GeV/c by means of a larger photon detector (a multiwire-multipad proportional chamber) and a longer proximity gap which will improve the photon detection geometrical efficiency and the angular resolution, respectively.
Cisbani, Evaristo; Colilli, Stefano; Cusanno, Francesco; Fratoni, Rolando; Frullani, Salvatore; Garibaldi, Franco; Giuliani, Fausto; Gricia, Massimo; Lucentini, Maurizio; Santavenere, Fabio; Urciuoli, Guido; Iodice, Mauro; Argentieri, A.; de Cataldo, Giacinto; De Leo, Raffaele; Lagamba, Luigi; Marrone, Stefano; Nappi, E.; Camsonne, Alexandre; Kross, Brian; Michaels, Robert; Reitz, Bodo; Segal, John; Wojtsekhowski, Bogdan; Zorn, Carl; Monno, E.; Breuer, Herbert
Scintillation proximity radioimmunoassay utilizing 125I-labeled ligands
A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an /sup 125/I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the /sup 125/I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.
Udenfriend, S.; Gerber, L.D.; Brink, L.; Spector, S.
Analysis of failed Van Straten LPM proximal interphalangeal prostheses.
The two-piece Van Straten Leuwen Poeschmann Metal (LPM) prosthesis was intended for the proximal interphalangeal joints. However, revision rates of 29% after 19 months were reported, as well as massive osteolysis. Five failed LPM titanium-niobium coated cobalt chromium components were obtained, three distal and two proximal, and subjected to a forensic retrieval analysis. Components were analyzed using a Talysurf contacting profilometer, ZYGO noncontacting profilometer, and environmental-scanning electron microscope. All components were heavily worn. In some regions the titanium-niobium coating had been scratched and penetrated. Elsewhere this coating had been removed where there was minimal scratching, which may have been due to corrosion between the coating and substrate. The osteolysis reported clinically was likely to be linked to the wear debris from the failed titanium-niobium coating and substrate. PMID:22989733
Bone, M C; Cunningham, J L; Lord, J; Giddins, G; Field, J; Joyce, T J
Scintillation Proximity Radioimmunoassay Utilizing 125I-Labeled Ligands
NASA Astrophysics Data System (ADS)
A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an 125I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the 125I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.
Udenfriend, Sidney; Diekmann Gerber, Louise; Brink, Larry; Spector, Sydney
Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors
NASA Technical Reports Server (NTRS)
We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 micrometers, 1450 times the mean-free path.
Sadlier, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.
Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors
NASA Technical Reports Server (NTRS)
We have found experimentally that the critical current of a square superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. The observed behavior has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. We have observed the proximity effect in these devices over extraordinarily long lengths exceeding 100 microns.
Sadleir, John E.; Smith, Stephen J.; Bandler, SImon R.; Chervenak, James A.; Clem, John R.
Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors
NASA Technical Reports Server (NTRS)
We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 micrometers, 1450 times the mean-free path.
Sadleir, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.
Space station proximity operations windows: Human factors design guidelines
NASA Technical Reports Server (NTRS)
Proximity operations refers to all activities outside the Space Station which take place within a 1-km radius. Since there will be a large number of different operations involving manned and unmanned vehicles, single- and multiperson crews, automated and manually controlled flight, a wide variety of cargo, and construction/repair activities, accurate and continuous human monitoring of these operations from a specially designed control station on Space Station will be required. Total situational awareness will be required. This paper presents numerous human factors design guidelines and related background information for control windows which will support proximity operations. Separate sections deal with natural and artificial illumination geometry; all basic rendezvous vector approaches; window field-of-view requirements; window size; shape and placement criteria; window optical characteristics as they relate to human perception; maintenance and protection issues; and a comprehensive review of windows installed on U.S. and U.S.S.R. manned vehicles.
Haines, Richard F.
Superconducting proximity effect in the presence of strong spin scattering.
We report measurements of the four terminal temperature dependent resistance of narrow Au wires implanted with 100 ppm Fe impurities in proximity to superconducting Al films. The wires show an initial decrease in resistance as the temperature is lowered through the superconducting transition of the Al films, but then show an increase in resistance as the temperature is lowered further. In contrast to the case of pure Au wires in contact with a superconducting film, the resistance at the lowest temperatures rises above the normal state resistance. Analysis of the data shows that, in addition to contributions from magnetic scattering and electron-electron interactions, the temperature dependent resistivity shows a substantial contribution from the superconducting proximity effect, which exists even in the presence of strong spin scattering.
Eom, J.; Aumentado, J.; Chandrasekhar, V.; Baldo, P. M.; Rehn, L. E.; Materials Science Division; Sejong Univ.; Northwestern Univ.
Aircraft Proximity Maps Based on Data-Driven Flow Modeling
With the forecast increase in air traffic demand over the next decades, it is imperative to develop tools to provide traffic flow managers with the information required to support decision making. In particular, decision-support tools for traffic flow management should aid in limiting controller workload and complexity, while supporting increases in air traffic throughput. While many decision-support tools exist for short-term traffic planning, few have addressed the strategic needs for medium- and long-term planning for time horizons greater than 30 minutes. This paper seeks to address this gap through the introduction of 3D aircraft proximity maps that evaluate the future probability of presence of at least one or two aircraft at any given point of the airspace. Three types of proximity maps are presented: presence maps that indicate the local density of traffic; conflict maps that determine locations and probabilities of potential conflicts; and outliers maps that evaluate the probability of conflict due t...
Sala³n, Erwan; Vela, Adan; Feron, Eric
STRaND-2: Visual inspection, proximity operations & nanosatellite docking
NASA Astrophysics Data System (ADS)
The Surrey Training Research and Nanosatellite Demonstrator (STRaND) programme has been success in identifying and creating a leading low-cost nanosatellite programme with advanced attitude and orbit control system (AOCS) and experimental computing platforms based on smart-phone technologies. The next demonstration capabilities, that provide a challenging mission to the existing STRaND platform, is to perform visual inspection, proximity operations and nanosatellite docking. Visual inspection is to be performed using a COTS LIDAR system to estimate range and pose under 100 m. Proximity operations are controlled using a comprehensive guidance, navigation and control (GNC) loop in a polar form of the Hills Clohessy Wiltshire (HCW) frame including J2 perturbations. And finally, nanosatellite docking is performed at under 30 cm using a series of tuned magnetic coils. This paper will document the initial experiments and calculations used to qualify LIDAR components, size the mission thrust and tank requirements, and air cushion table demonstrations of the docking mechanism.
Bridges, C. P.; Taylor, B.; Horri, N.; Underwood, C. I.; Kenyon, S.; Barrera-Ars, J.; Pryce, L.; Bird, R.
DIFFERENTIAL ENVIRONMENTAL SPATIAL PATTERNING (ESP) RECREATES PROXIMAL-DISTAL AXIAL PATTRENS- ferential Environmental Spatial Patterning, ESP) technique as an in vitro means to generate developmentally relevant differ- entiation patterns. We demonstrated that ESP could emulate proximal-distal differentiation
Voldman, Joel
Defective Proximal Tubule Lysosomal Acidification by Bence Jones Proteins
Proximal tubule handling of two human Bence Jones proteins (neutral and acidic BJP) was evaluated using protein A-gold labelling. After 30 min of acute light-chain infusion into 6 rats (alone or in combination with dinitrophenyl-aminopropyl-methylamine [DAMP]), kidney biopsies were processed for immunoelectron microscopy. Antibodies directed at monoclonal lambda light chains, mannose-6-phosphate cation-independent receptor (MPR) and DAMP were used.Labelling density (number
Ana Lucia Nicastri; Maria Josķ BrandŃo de Almeida Prado; Antonio Sesso; Euthymia BrandŃo de Almeida Prado
Proximal row carpectomyŚan adequate procedure in carpal collapse
Proximal row carpectomy (PRC) is an established procedure in the treatment of advanced radiocarpal arthritis. The aim of this\\u000a study was to evaluate the individual, functional and radiological results in relation to the initial diagnosis. Seventeen\\u000a patients (15 men, two women), who had undergone PRC, were evaluated. Their average age at the time of the operation was 48Āyears\\u000a (range 21¢70Āyears).
Nikolaus A. Streich; Abdul K. Martini; Wolfgang Daecke
Radial shortening following a fracture of the proximal radius
Background and purpose The Essex-Lopresti lesion is thought to be rare, with a varying degree of disruption to forearm stability probable. We describe the range of radial shortening that occurs following a fracture of the proximal radius, as well as the short-term outcome in these patients. Patients and methods Over an 18-month period, we prospectively assessed all patients with a radiographically confirmed proximal radial fracture. Patients noted to have ipsilateral wrist pain at initial presentation underwent bilateral radiography to determine whether there was disruption of the distal radio-ulnar joint suggestive of an Essex-Lopresti lesion. Outcome was assessed after a mean of 6 (1.5¢12) months using clinical and radiographic results, including the Mayo elbow score (MES) and the short musculoskeletal function assessment (SMFA) questionnaire. One patient with a Mason type-I fracture was lost to follow-up after initial presentation. Results 60 patients had ipsilateral wrist pain at the initial assessment of 237 proximal radial fractures. Radial shortening of ? 2mm (range: 2¢4mm) was seen in 22 patients (mean age 48 (19¢79) years, 16 females). The most frequent mechanism of injury was a fall from standing height (10/22). 21 fractures were classified as being Mason type-I or type-II, all of which were managed nonoperatively. One Mason type-III fracture underwent acute radial head replacement. Functional outcome was assessed in 21 patients. We found an excellent or good MES in 18 of the 20 patients with a Mason type-I or type-II injury. Interpretation The incidence of the Essex-Lopresti lesion type is possibly under-reported as there is a spectrum of injuries, and subtle disruptions often go unidentified. A full assessment of all patients with a proximal radial fracture is required in order to identify these injuries, and the index of suspicion is raised as the complexity of the fracture increases. PMID:21504305
Human proximal femur bone adaptation to variations in hip geometry.
The study of bone mass distribution at proximal femur may contribute to understand the role of hip geometry on hip fracture risk. We examined how bone mineral density (BMD) of proximal femur adapts to inter individual variations in the femoral neck length (FNL), femoral neck width (FNW) and neck shaft angle (NSA). A parameterized and dimensionally scalable 3-D finite element model of a reference proximal femur geometry was incrementally adjusted to adopt physiological ranges at FNL (3.90-6.90cm), FNW (2.90-3.46cm), and NSA (109-141║), yielding a set of femora with different geometries. The bone mass distribution for each femur was obtained with a suitable bone remodelling model. The BMDs at the integral femoral neck (FN) and at the intertrochanteric (ITR) region, as well as the BMD ratio of inferomedial to superolateral (IM:SL) regions of FN and BMD ratio of FN:ITR were used to represent bone mass distribution. Results revealed that longer FNLs present greater BMD (g/cm(3)) at the FN, mainly at the SL region, and at the ITR region. Wider FNs were associated with reduced BMD at the FN, particularly at the SL region, and at the ITR region. Larger NSAs up to 129░ were associated with BMD diminutions at the FN and ITR regions and with increases of the IM:SL BMD ratio while NSAs larger than 129░ resulted in decrease of the IM:SL BMD ratio. These findings suggest hip geometry as moderator of the mechanical loading influence on bone mass distribution at proximal femur with higher FNL favoring the BMD of FN and ITR regions and greater FNW and NSA having the opposite effect. Augmented values of FNL and FNW seem also to favor more the BMD at the superolateral than at the inferomedial FN region. PMID:25016094
Machado, M M; Fernandes, P R; Zymbal, V; Baptista, F
Complex of myoglobin with phenol bound in a proximal cavity.
Sperm whale myoglobin (Mb) has weak dehaloperoxidase activity and catalyzes the peroxidative dehalogenation of 2,4,6-trichlorophenol (TCP) to 2,6-dichloroquinone. Crystals of Mb and of its more active G65T variant were used to study the binding of TCP, 4-iodophenol (4-IP) and phenol. The structures of crystals soaked overnight in a 10?mM solution of phenol revealed that a phenol molecule binds in the proximal cavity, forming a hydrogen bond to the hydroxyl of Tyr146 and hydrophobic contacts which include interactions with C? and C? of the proximal histidine His93. The phenol position corresponds to the strongest xenon binding site, Xe1. It appears that the ligand enters the proximal cavity through a gate formed by the flexible loops 79-86 and 93-103. TCP and 4-IP do not bind to Mb in this manner under similar conditions; however, it appears to be likely that dimethyl sulfoxide (DMSO), which was used at a concentration of 0.8?M to facilitate 4-IP dissolution, binds in the phenol/Xe1 binding site. In this structure, a water molecule coordinated to the heme iron was replaced by an oxygen molecule, reflecting the reduction of the heme. Crystals of Mb and G65T Mb soaked for 5-10?min did not show bound phenol. Kinetic studies of TCP dechlorination showed that phenol has a dual effect: it acts as a competitive inhibitor that is likely to interfere with TCP binding at the heme edge and as a weak activator, likely through binding in the proximal cavity. The lack of phenol bound at the heme edge in the crystal structures suggests that its inhibitory binding only takes place when the heme is activated by hydrogen peroxide. PMID:23192025
Huang, Xiao; Wang, Chunxue; Celeste, Lesa R; Lovelace, Leslie L; Sun, Shenfang; Dawson, John H; Lebioda, Lukasz
Essential genes in proximal 3L heterochromatin of Drosophila melanogaster
We have further characterized essential loci within the centric heterochromatin of the left arm of chromosome 3 (3L) of Drosophila melanogaster, using EMS, radiation and P element mutagenesis. We failed to find any new essential genes, a result that suggests a lower-than-average gene density in this region. Mutations affecting expression of the most proximal gene [lethal 1, l1 or l(3)80Fj
S. Schulze; D. A. R. Sinclair; E. Silva; K. A. Fitzpatrick; M. Singh; V. K. Lloyd; K. A. Morin; J. Kim; D. G. Holm; J. A. Kennison; B. M. Honda
Morphological analysis of the proximal femur using quantitative computed tomography
The anatomy of the proximal femur was studied in 35 specimens using quantitative computed tomography (QCT) and compared with\\u000a anatomical sections studied by plane radiography and gross dissection. We found the primary supporting structure of the femoral\\u000a head to be the primary compressive strut, which is a dense column of trabecular bone projecting from the pressure buttress\\u000a of the medial
James B. Stiehl; Donald Jacobson; Guilermo Carrera
Evaluation of resist models for fast optical proximity correction
One of the most prominent process non-linearities, which are summarized under 'proximity effects' is line-shortening. Line- shortening is poorly modeled by phenomenological lithography simulation -- even when resist models are used, which deliver reasonable results for process windows and resist edge profiles. So the challenge for a simulation-based OPC tool is not only the required speed, but also a lack
Christoph Dolainsky; Wilhelm Maurer; Thomas Waas
Geometrical E-beam proximity correction for raster scan systems
High pattern fidelity is a basic requirement for the generation of masks containing sub micro structures and for direct writing. Increasing needs mainly emerging from OPC at mask level and x-ray lithography require a correction of the e-beam proximity effect. The most part of e-beam writers are raster scan system. This paper describes a new method for geometrical pattern correction
Nikola Belic; Hans Eisenmann; Hans Hartmann; Thomas Waas
Characterization of cytoplasmic caspase-2 activation by induced proximity
Caspase-2 is an initiator caspase, activated in response to heat shock and other stressors that induce apoptosis. Activation of caspase-2 requires induced proximity resulting after recruitment to caspase-2 activation complexes, such as the PIDDosome. We have adapted bimolecular fluorescence complementation (BiFC) to measure caspase-2 induced proximity in real time, in single cells. Non-fluorescent fragments of the fluorescent protein Venus that can associate to reform the fluorescent complex were fused to caspase-2 allowing visualization and kinetic measurements of caspase-2 induced proximity after heat shock and other stresses. This revealed that the caspase-2 activation platform occurred in the cytosol and not in the nucleus in response to heat shock, DNA damage, cytoskeletal disruption and other treatments. Activation, as measured by this approach, in response to heat shock, was RAIDD-dependent and upstream of mitochondrial outer membrane permeabilization. Furthermore we identify Hsp90? as a key negative regulator of heat shock-induced caspase-2 activation. PMID:19782032
Bouchier-Hayes, Lisa; Oberst, Andrew; McStay, Gavin P.; Connell, Samuel; Tait, Stephen W.G.; Dillon, Christopher P.; Flanagan, Jonathan M.; Beere, Helen M.; Green, Douglas R.
Allograft reconstruction for symptomatic chronic complete proximal hamstring tendon avulsion.
Complete proximal hamstring tendon avulsion is an uncommon injury that can cause significant disability in young, athletic individuals. Surgical reattachment is recommended and can be performed on a delayed basis if the tissue is sufficiently mobile. We report 2-year follow up for two cases where interpositional allograft tissue was used for reconstruction because the tendon was too retracted for primary repair. Two 30-year-old patients with complete proximal hamstring avulsion at least 2 years earlier reported severe hamstring weakness and restrictions with respect to sport and recreational activities. Proximal hamstring tendon reconstruction with Achilles tendon allograft was performed for both patients. They were immobilized for 8 weeks with the hip in extension and the knee in flexion using a custom orthosis, followed by physical therapy and weight bearing as tolerated. The patients were followed for over 2 years after the surgery and were evaluated with physical examination, isokinetic strength testing and detailed questions about their function. Following the procedure, both patients returned to a more active lifestyle that was greatly improved with respect to participation in sport and function. This procedure should be considered as a salvage operation as the patients did not return to completely normal function and demonstrated hamstring weakness on the operated side. PMID:18682918
Marx, Robert G; Fives, Gregory; Chu, Samuel K; Daluiski, Aaron; Wolfe, Scott W
Stability of proximal femoral grafts in canine hip arthroplasty.
In a canine model, the fixation stability of a prosthesis and proximal bone graft composite were measured relative to the distal femur. One group had the prosthesis graft composite cemented into the distal femur. The second group had the prosthesis graft composite press fit into the distal femur for biologic ingrowth. Displacements of the proximal femoral grafts relative to the host bone in each group were measured after ex vivo (acute with graft) implantation and 4 months after implantation. A third group with no osteotomy (acute intact) simulated perfect graft to host bone union. Relative displacements representing 6 degrees freedom (translation and rotation) were calculated from the displacement values measured by 9 eddy current transducers. Measurements of displacement were used to test the hypothesis that distal press fit fixation equals distal cement fixation at 4 months after implantation. In all cases the measured translations and rotations of the graft to implant construct were small and of a magnitude that should encourage bone ingrowth (< 0.05 mm and < 0.1 degree, respectively). The stability of the press fit group at 4 months was not significantly different from the cemented group in axial and transverse displacement during axial and transverse loading, respectively. There was no difference in stabilities at 4 months between distal press fit and cemented fixation in hip replacements requiring a proximal femoral graft. PMID:9269179
Heiner, J P; Kohles, S S; Manley, P A; Vanderby, R; Markel, M D
Hand proximity facilitates spatial discrimination of auditory tones
The effect of hand proximity on vision and visual attention has been well documented. In this study we tested whether such effect(s) would also be present in the auditory modality. With hands placed either near or away from the audio sources, participants performed an auditory-spatial discrimination (Experiment 1: left or right side), pitch discrimination (Experiment 2: high, med, or low tone), and spatial-plus-pitch (Experiment 3: left or right; high, med, or low) discrimination task. In Experiment 1, when hands were away from the audio source, participants consistently responded faster with their right hand regardless of stimulus location. This right hand advantage, however, disappeared in the hands-near condition because of a significant improvement in left hand's reaction time (RT). No effect of hand proximity was found in Experiments 2 or 3, where a choice RT task requiring pitch discrimination was used. Together, these results that the perceptual and attentional effect of hand proximity is not limited to one specific modality, but applicable to the entire ōspaceö near the hands, including stimuli of different modality (at least visual and auditory) within that space. While these findings provide evidence from auditory attention that supports the multimodal account originally raised by Reed et al. (2006), we also discuss the possibility of a dual mechanism hypothesis to reconcile findings from the multimodal and magno/parvocellular account. PMID:24966839
Tseng, Philip; Yu, Jiaxin; Tzeng, Ovid J. L.; Hung, Daisy L.; Juan, Chi-Hung
Deriving the number of jobs in proximity services from the number of inhabitants in French rural
Deriving the number of jobs in proximity services from the number of inhabitants in French rural a minimum requirement approach to derive the number of jobs of proximity services per inhabitant observe that the minimum number of service jobs per inhabitant (interpreted as jobs of proximity services
Paris-Sud XI, Universit├® de
Influence of PWM on the Proximity Loss in Permanent-Magnet Brushless AC Machines
A winding copper loss can be significantly increased due to skin and proximity eddy-current effects. The skin and proximity losses due to fundamental frequency current have been investigated in literature, but the influence of pulsewidth modulation (PWM) on the skin and proximity losses has not been reported. In this paper, a 2-D finite element method is employed to analyze the
S. Iwasaki; Rajesh P. Deodhar; Yong Liu; Adam Pride; Z. Q. Zhu; Jonathan James Bremner
Proximal watershed validation of a remote sensing-based streamflow estimation model
Proximal watershed validation of a remote sensing- based streamflow estimation model Blake P model in four regionally proximate south-central Texas watersheds. Sandies Creek watershed (1420 km2 additional proximal watersheds of varying spatial dimension (860 km2 ┬Ł 2940 km2 ), soils, land cover
Texas at San Antonio, University of
iPiano: Inertial Proximal Algorithm for Non-convex Optimization
explicit (forward) gradient steps w.r.t. the smooth part with proximal (backward) steps w.r.t. the non, (xn - xn-1 ) as inertial term, and (I + g)-1 as backward or proximal step. For g 0 the proximal step (possi- bly non-differentiable) function. The algorithm iPiano combines forward- backward splitting
Teschner, Matthias
Fatty marrow conversion of the proximal femoral metaphysis in transient bone marrow edema syndrome
Introduction In the proximal femoral meta- physis, hematopoietic marrow is predominant during the adult stage of life. The conversion of hematopoietic marrow to fatty marrow in the proximal femoral meta- physis has been suggested as an etiologic factor of ischemia in the pathogenesis of femoral head osteone- crosis. To determine whether the chronology of fatty marrow conversion of the proximal
Shin-Yoon Kim; Kyung-Hoi Koo; Kuen-Tak Suh; Yong-Sik Kim; Yoon-Je Cho; Byung-Woo Min; Yong-Chan Ha; Jung-Ah Choi
This study is a prospective evaluation of the Less Invasive Stabilization System (LTSS) for the treatment of high-energy tibial plateau and proximal tibial fractures treated between November, 1998 and June, 2000. Thirty-two patients sustained thirty-five acute fractures of the tibial plateau (25) or proximal tibia (10). These patients were injured primarily in blunt trauma accidents, with eighteen having multiple fractures, fifteen having ipsilateral extremity fractures, and eleven having major knee ligament injuries. Seventeen patients had open fractures. Thirty-four patients healed their fractures, with one developing a nonunion. Two patients developed infections, both following Type III open fractures. Final range of motion averaged 2 to 116 degrees. Alignment was well maintained, with no patient losing the alignment that was obtained in the operating room. The tibial LISS system worked well at stabilizing difficult fractures of the tibial plateau and proximal tibia with a low incidence of complications in this preliminary study with short-term follow-up. PMID:14563009
Stannard, J P; Wilson, T C; Volgas, D A; Alonso, J E
The proximate unit in Chinese handwritten character production
In spoken word production, a proximate unit is the first phonological unit at the sublexical level that is selectable for production (O'Seaghdha et al., 2010). The present study investigated whether the proximate unit in Chinese handwritten character production is the stroke, the radical, or something in between. A written version of the form preparation task was adopted. Chinese participants learned sets of two-character words, later were cued with the first character of each word, and had to write down the second character (the target). Response times were measured from the onset of a cue character to the onset of a written response. In Experiment 1, the target characters within a block shared (homogeneous) or did not share (heterogeneous) the first stroke. In Experiment 2, the first two strokes were shared in the homogeneous blocks. Response times in the homogeneous blocks and in the heterogeneous blocks were comparable in both experiments (Experiment 1: 687 vs. 684 ms, Experiment 2: 717 vs. 716). In Experiment 3 and 4, the target characters within a block shared or did not share the first radical. Response times in the homogeneous blocks were significantly faster than those in the heterogeneous blocks (Experiment 3: 685 vs. 704, Experiment 4: 594 vs. 650). In Experiment 5 and 6, the shared component was a Gestalt-like form that is more than a stroke, constitutes a portion of the target character, can be a stand-alone character itself, can be a radical of another character but is not a radical of the target character (e.g., ▒ in , , , ; called a logographeme). Response times in the homogeneous blocks were significantly faster than those in the heterogeneous blocks (Experiment 5: 576 vs. 625, Experiment 6: 586 vs. 620). These results suggest a model of Chinese handwritten character production in which the stroke is not a functional unit, the radical plays the role of a morpheme, and the logographeme is the proximate unit. PMID:23950752
Chen, Jenn-Yeu; Cherng, Rong-Ju
Percutaneous Stabilization of Impending Pathological Fracture of the Proximal Femur
Objective: Percutaneous osteosynthesis plus cementoplasty (POPC) is a minimally invasive technique that has never been reported before and that we have prospectively evaluated for patients with impending pathological fracture of the proximal femur. Methods: We performed POPC in 12 patients (3 males, 9 females) with metastasis of the proximal femur with a high risk of fracture (Mirels' score {>=}8) between February 2010 and July 2011. Patients were not candidates for standard surgical stabilization. We analyzed the feasibility, duration, and complication of the procedure, the risk of fracture, the decrease in pain (Visual Analog Scale, VAS), and length of stay in hospital. Data were prospectively collected in all patients. Results: The mean Mirels' score was 9.8 {+-} 1.2 (range, 8-11). The technical success was 100%. POPC was performed under general anesthesia (n = 6) or conscious sedation (n = 6). The mean duration was 110 {+-} 43 (range, 60-180) minutes. All patients stood up and walked the second day after the procedure. The average length of stay in the hospital was 4 {+-} 1.6 (range, 2-7) days. We experienced two hematomas in two patients and no thromboembolic complication. For symptomatic patients (n = 8), VAS decreased from 6.5/10 (range, 2-9) before treatment to 1/10 (range, 0-3) 1 month after. No fracture occurred after a median follow-up of 145 (range, 12-608) days. Conclusions: POPC for impending pathological fracture of the proximal femur seems to be a promising alternative for cancer patients who are not candidates for surgical stabilization. Further studies are required to confirm this preliminary experience.
Deschamps, Frederic, E-mail: email@example.com; Farouil, Geoffroy, E-mail: firstname.lastname@example.com; Hakime, Antoine, E-mail: firstname.lastname@example.com; Teriitehau, Christophe, E-mail: email@example.com; Barah, Ali, E-mail: firstname.lastname@example.com; Baere, Thierry de, E-mail: firstname.lastname@example.com [Institut Gustave Roussy, Interventional Radiology Department (France)
The proximate unit in Chinese handwritten character production.
In spoken word production, a proximate unit is the first phonological unit at the sublexical level that is selectable for production (O'Seaghdha et al., 2010). The present study investigated whether the proximate unit in Chinese handwritten character production is the stroke, the radical, or something in between. A written version of the form preparation task was adopted. Chinese participants learned sets of two-character words, later were cued with the first character of each word, and had to write down the second character (the target). Response times were measured from the onset of a cue character to the onset of a written response. In Experiment 1, the target characters within a block shared (homogeneous) or did not share (heterogeneous) the first stroke. In Experiment 2, the first two strokes were shared in the homogeneous blocks. Response times in the homogeneous blocks and in the heterogeneous blocks were comparable in both experiments (Experiment 1: 687 vs. 684 ms, Experiment 2: 717 vs. 716). In Experiment 3 and 4, the target characters within a block shared or did not share the first radical. Response times in the homogeneous blocks were significantly faster than those in the heterogeneous blocks (Experiment 3: 685 vs. 704, Experiment 4: 594 vs. 650). In Experiment 5 and 6, the shared component was a Gestalt-like form that is more than a stroke, constitutes a portion of the target character, can be a stand-alone character itself, can be a radical of another character but is not a radical of the target character (e.g., ▒ in , , , ; called a logographeme). Response times in the homogeneous blocks were significantly faster than those in the heterogeneous blocks (Experiment 5: 576 vs. 625, Experiment 6: 586 vs. 620). These results suggest a model of Chinese handwritten character production in which the stroke is not a functional unit, the radical plays the role of a morpheme, and the logographeme is the proximate unit. PMID:23950752
Chen, Jenn-Yeu; Cherng, Rong-Ju
Does tamsulosin change the management of proximally located ureteral stones?
The objective of this study is to assess the efficacy of an alpha-1 adrenergic receptor blocking agent on the spontaneous passage of proximal ureteral calculi < or =10 mm. 92 patients having single radio-opaque proximal ureteral stone < or =10 mm were randomized into two groups. Group 1 patients (n = 50) were followed with classical conservative approach and patients in Group 2 (n = 42) additionally received tamsulosin, 0.4 mg/day during 4 weeks follow-up. The stone passage rates, stone expulsion time, VAS score, change in colic episodes, and hospital re-admission rates for colicky pain were compared. The patients were furthermore stratified according to stone diameters <5 and 5-10 mm. The data of these subgroups were also compared. Stone expulsion rates showed statistically significant difference between tamsulosin receivers and non-receivers (35.7 vs 30%, p = 0.04). Time to stone expulsion period was also shortened in those receiving tamsulosin (8.4 +/- 3.3 vs 11.6 +/- 4.1 days, p = 0.015). Likewise, the mean VAS score and renal colic episodes during follow-up period were significantly diminished in Group 2 patients (4.5 +/- 2.3 vs 8.8 +/- 2.9, p < 0.01 and 66.6 vs 36%, p = 0.001, respectively). Among the stones <5 mm, tamsulosin receiving patients had higher spontaneous passage rate (71.4 vs 50%, p < 0.001). The prominent effect of tamsulosin on the 5-10 mm stones was the relocation of the stones to a more distal part of ureter (39.3 vs 18.7%, p = 0.001). Administration of tamsulosin in the medical management of proximal ureteral calculi can facilitate the spontaneous passage rate in the stone <5 mm and the relocation of the stones between 5 and 10 mm to more distal part of the ureter. PMID:20182703
Yencilek, Faruk; Erturhan, Sakip; Canguven, Onder; Koyuncu, Hakan; Erol, Bulent; Sarica, Kemal
Proximity Effects and Nonequilibrium Superconductivity in Transition-Edge Sensors
NASA Technical Reports Server (NTRS)
We have recently shown that normal-metal/superconductor (N/S) bilayer TESs (superconducting Transition-Edge Sensors) exhibit weak-link behavior.l Here we extend our understanding to include TESs with added noise-mitigating normal-metal structures (N structures). We find TESs with added Au structures also exhibit weak-link behavior as evidenced by exponential temperature dependence of the critical current and Josephson-like oscillations of the critical current with applied magnetic field. We explain our results in terms of an effect converse to the longitudinal proximity effect (LoPE) 1, the lateral inverse proximity effect (LaiPE), for which the order parameter in the N/S bilayer is reduced due to the neighboring N structures. Resistance and critical current measurements are presented as a function of temperature and magnetic field taken on square Mol Au bilayer TESs with lengths ranging from 8 to 130 {\\mu}m with and without added N structures. We observe the inverse proximity effect on the bilayer over in-plane distances many tens of microns and find the transition shifts to lower temperatures scale approximately as the inverse square of the in- plane N-structure separation distance, without appreciable broadening of the transition width. We also present evidence for nonequilbrium superconductivity and estimate a quasiparticle lifetime of 1.8 \\times 10-10 s for the bilayer. The LoPE model is also used to explain the increased conductivity at temperatures above the bilayer's steep resistive transition.
Sadleir, John E.; Smith, Stephen J.; Robinson, Ian K.; Finkbeiner, Fred M.; Chervenak, James A.; Bandler, Simon R.; Eckart, Megan E.; Kilbourne, Caroline A.
Proximity effect correction for 20nm dimension patterning
NASA Astrophysics Data System (ADS)
Electron Beam Direct Writing (EBDW) has been applied to various applications such as prototyping or small amount production of electronic devices. Originally, proximity effect in EBDW is considered as the problem of the background energy difference caused by the pattern density distribution. However, the critical dimensions of target patterns are getting smaller, we cannot ignore influences of the forward scattering. Theoretically, when the critical dimension is close to 3 or 4 times of forward scattering range, influence cannot be ignored. For example, in case of that corresponds, fabricating 20 nm dimension patterns by Nano Imprint Lithography (NIL) which is significant candidate of next generation lithography technology. Because it requires original dimension (1:1) mold. Therefore proximity effect correction (PEC) system which considers the forward scattering must be important. We developed simulation-based proximity effect correction system combined with data format conversion, works on Linux PC cluster. And we exposed the patterns which are dose compensated by this system. Firstly, we have speculated parameters about backward scattering parameters by exposing 100 nm line and space patterns. We got following parameters, beta (backward scattering range) = 32 um, eta (backward scattering coefficient) = 2.5. Secondary, we have exposed Line and Space patterns whose dimensions are from 20 nm to 100 nm. We found that smaller and dense patterns have trend to be over exposed and bigger. Experimental specification is following, EB Direct Writing system is JBX-9300FS (100keV acc. Voltage) by JEOL co.ltd,, Japan) , resist is HSQ (FOx 12) by Dow Corning co., United States), substrate is Si.
Tsunoda, Dai; Shoji, Masahiro; Tatsugawa, Mitsuko; Tsunoe, Hiroyuki; Iino, Yusuke; Jedrasik, Piotr
Survivin Mediates Renal Proximal Tubule Recovery from AKI
AKI induces the renoprotective upregulation of survivin expression in kidney epithelial cells, but the underlying mechanisms have not been identified. To determine the role of survivin in renal recovery from AKI, we generated mice with renal proximal tubule-specific deletion of survivin (survivinptKO). Renal survivin expression increased substantially in response to ischemia-reperfusion (I/R) injury in control littermates but remained minimal in survivinptKO mice. Functional and histologic data indicated similar degrees of renal injury in survivinptKO and control mice 24 hours after reperfusion, but recovery was markedly delayed in survivinptKO mice. In MCT cells, a mouse renal proximal tubule cell line, ATP depletion by antimycin A treatment upregulated survivin expression through a phospho-STAT3¢dependent pathway. In wild-type mice, inhibition of STAT3 kinase diminished I/R-induced upregulation of STAT3 phosphorylation and survivin expression and delayed recovery. Furthermore, I/R injury activated Notch-2 signaling, and a ?-secretase inhibitor suppressed I/R-induced Notch-2 signaling, STAT3 phosphorylation, and survivin expression and delayed recovery. In MCT cells, inhibition of ?-secretase similarly attenuated antimycin A-induced Notch-2 activation, upregulation of survivin, and phosphorylation of STAT3, but STAT3 kinase inhibition did not prevent Notch-2 activation. Therefore, these data suggest that STAT3 phosphorylation and subsequent upregulation of survivin expression mediated by Notch-2 signaling in renal proximal tubule epithelial cells aid in the functional and structural recovery of the kidney from AKI. PMID:23949800
Chen, Jianchun; Chen, Jian-Kang; Conway, Edward M.
Endoluminal vacuum therapy for iatrogenic perforation of the proximal oesophagus.
Iatrogenic perforation of the upper gastrointestinal tract is one of the most serious complications of upper gastrointestinal endoscopy, with high rates of morbidity and mortality. Treatment is challenging because stent placement or surgical repair of the perforation in this area is often impossible. We report on two cases of iatrogenic perforations of the very proximal oesophagus and distal hypopharynx which could be successfully closed by using an endoluminal vacuum sponge treatment for 5 days. Thus, the endoluminal vacuum therapy may be a useful alternative to surgery in such cases of difficultly managable perforations of the upper oesophagus. PMID:24622870
M÷schler, O; M³ller, M K
Proximity Effects and Vortex Dynamics in Nanostructured Superconductors
NASA Astrophysics Data System (ADS)
We report transport measurements on triangular arrays of proximity-coupled superconducting islands placed on normal-metal substrates. The superconducting islands are well-understood coherent systems with long-range electron interactions, while the intervening normal metal channels introduce known dissipation into the system. We show how by changing the island spacing, we can tune characteristics such as the critical temperature and field. The arrays undergo a Kosterlitz-Thouless vortex-unbinding phase transition at zero-field, and we observe frustration-induced magnetoresistance oscillations at finite fields. We also observe unusual cusp-like behavior in resistance vs temperature at finite magnetic fields
Eley, Serena; Mason, Nadya
Nanofabrication of nanopattern and microdevices using contact/proximity lithography
NASA Astrophysics Data System (ADS)
The oldest lithography technique contact/proximity printing are widely used for research activity, most MEMS, Bio-Chip and Optical Electro devices can be fabricated by this method. In this paper, deep submicron 1x mask can be fabricated easily by using e-beam exposure, chemically amplified resist (CAR) and Cr dry etching, a chemical shrink method using dry/wet etching technology was proposed for nanofabrication by using Cr film as hard mask. Micro channel for biochip as well as micro lens for Optical Electro devices can easily be fabricated on glass and quartz substrates by this method.
Ting, Yung-Chiang; Shy, Shyi-Long; Lee, Ming-Chun; Dai, Bau-Tong
Pathology Case Study: Pain in Left Proximal Medial Thigh
NSDL National Science Digital Library
This is a skeletal and soft tissue pathology case study presented by the University of Pittsburgh Department of Pathology in which a 9-year-old girl has left proximal medial thigh pain. Visitors are given both the microscopic and gross descriptions, including images, and are given the opportunity to diagnose the patient. This is an excellent resource for students in the health sciences to familiarize themselves with using patient history and laboratory results to diagnose. It is also a helpful site for educators to use to introduce or test student learning in skeletal and soft tissue pathology.
Cohen, Lance; Dickman, Paul S.; Parizhskaya, Maria
Superconducting Proximity Effect in Single-Crystal Nanowires
-resistance-ratio of the nanowires has also been observed. Possible mechanisms for this proximity effect are discussed based on these experimental observations. v ACKNOWLEDGEMENTS I would like to express my deep appreciation to my research advisor, Dr. Wenhao Wu, for his... extensive hands-on teaching in the lab and tireless inspiration during my time as a Ph.D. student. He led me into the field of superconducting nanowires. With his insight and expertise, I have had a lot of fun solving difficult technical problems...
Liu, Haidong
Ground plane insulating coating for proximity focused devices
A thin layer of alumina (aluminum oxide) is coated onto the ground plane of a microchannel plate (MCP) without covering the pores of the MCP so it does not effect the performance. The coating is sputtered onto the ground plane at a very steep angle. The addition of the thin dielectric coating of alumina greatly improves the spatial resolution of proximity focused image intensifiers using a narrow gap between the phosphor screen and the MCP. With the coating on the ground plane and the same gap the phosphor screen can be ran at 9000 volts, as compared to 3 kV without the coating.
Power, Gary D. (Manteca, CA)
Ground plane insulating coating for proximity focused devices
A thin layer of alumina (aluminum oxide) is coated onto the ground plane of a microchannel plate (MCP) without covering the pores of the MCP so it does not effect the performance. The coating is sputtered onto the ground plane at a very steep angle. The addition of the thin dielectric coating of alumina greatly improves the spatial resolution of proximity focused image intensifiers using a narrow gap between the phosphor screen and the MCP. With the coating on the ground plane and the same gap the phosphor screen can be ran at 9000 volts, as compared to 3 kV without the coating. 3 figs.
Power, G.D.
Localized Pigmented Villonodular Synovitis of the Proximal Tibiofibular Joint
Pigmented villonodular synovitis (PVNS) is a rare disease. It is a benign neoplastic process typically affecting young to middle-aged adults and most commonly involving the knee, hip, and shoulder joints. The symptoms include diffuse pain and swelling with discomfort. We report a rare case of localized PVNS originating at the proximal tibiofibular joint in a 39-year-old female patient with radiologic changes for short duration of time. The clinical history, plain radiographs, magnetic resonance imaging, and pathologic findings of the reported patient were reviewed. Complete surgical excision was performed and there was no evidence of recurrence after one-year follow-up. PMID:25505708
Kwon, Jae Ho; Han, Jae Hwi; Almeida, Vivian RD'; Kim, Seong Hyun; Park, Hai Jin
A General Simulation Method for Multiple Bodies in Proximate Flight
NASA Technical Reports Server (NTRS)
Methods of unsteady aerodynamic simulation for an arbitrary number of independent bodies flying in close proximity are considered. A novel method to efficiently detect collision contact points is described. A method to compute body trajectories in response to aerodynamic loads, applied loads, and inter-body collisions is also given. The physical correctness of the methods are verified by comparison to a set of analytic solutions. The methods, combined with a Navier-Stokes solver, are used to demonstrate the possibility of predicting the unsteady aerodynamics and flight trajectories of moving bodies that involve rigid-body collisions.
Meakin, Robert L.
Evaluation of benzalkonium chloride chemoneurolytic proximal gastric vagotomy
Background: Transmucosal chemoneurolytic injection of benzalkonium chloride (BAC) has previously been shown to duplicate operative proximal\\u000a gastric vagotomy (PGV) in controlling gastric acid secretion. In this study, BAC was evaluated as to efficacious dose, methods\\u000a of delivery, and systemic toxicities.\\u000a \\u000a \\u000a \\u000a \\u000a Methods: Sham celiotomy, operative PGV controls, transmucosal injections through a gastrotomy, and transserosal injections of BAC\\u000a (saline controls, 0.625, 1.25,
A. G. El-Ghazzawy; N. Gupta; T. J. Swope; A. D. Kulkarni; W. M. Panneton; S. M. Robinson; M. L. Niehoff; D. L. Kaminski; C. H. Andrus
Proximity effect thermometer for local temperature measurements on mesoscopic samples.
Using the strong temperature-dependent resistance of a normal metal wire in proximity to a superconductor, we have been able to measure the local temperature of electrons heated by flowing a direct-current (dc) in a metallic wire to within a few tens of millikelvin at low temperatures. By placing two such thermometers at different parts of a sample, we have been able to measure the temperature difference induced by a dc flowing in the samples. This technique may provide a flexible means of making quantitative thermal and thermoelectric measurements on mesoscopic metallic samples.
Aumentado, J.; Eom, J.; Chandrasekhar, V.; Baldo, P. M.; Rehn, L. E.; Materials Science Division; Northwestern Univ; Univ. of Chicago
Osteochondroma Arising from the Proximal Fibula: A Rare Presentation
Osteochondromas are commonly encountered benign tumours and they are characterized by cartilage capped bony growths that project from the surface of the affected bone. Osteochondromas tend to grow eccentrically rather than centrifugally. We are reporting a case of an 18-year-old male, who had presentation of a large, hard, irregular swelling over anterolateral aspect of his right leg. There was no neurovascular deficit in the extremity. Computed tomography showed that the origin of the tumour was probably proximal fibula. En-block excision of mass was done. A histopathological examination confirmed the diagnosis of a benign osteochondroma. Patient had uneventful recovery without any evidence of recurrence. PMID:24959469
Malgonde, Monika; Jain, Pramod
The proximal femur nail antirotation represents a new generation of intramedullary nailing devices for fixation of stable and unstable trochanteric fractures of the proximal femur. We report 3 cases of postoperative perforation of the helical blade through the femoral head into the hip joint without any signs of rotational or varus displacement of the fracture. PMID:18978550
Brunner, Alexander; J÷ckel, Jens Arne; Babst, Reto
Proximal femoral fractures: Principles of management and review of literature
Purpose The purpose of this study was to review the principles involved in the management of proximal femoral fractures as reported in the literature. Methods: A medical literature search in the MEDLINE (PubMed) and Cochrane database was undertaken to review strategies and principles in proximal femoral fracture treatment. Randomized control trials and meta analysis were given preference while case reports/small series were rejected. Results and conclusions: Early anatomical reduction and surgical fixation remains the best option to reduce the risk of complications like non-union and avascular necrosis in treating fracture neck femurs. Cancellous screws continue to be the preferred treatment for fixation of neck femur fractures in younger population until the benefit of using sliding hip screws is validated by large multicentric studies. In the geriatric age group, early prosthetic replacement brings down the mortality and morbidity associated with neck femur fractures. Sliding hip screw (DHS) is the best available option for stable inter trochanteric fractures. The use of intramedullary nails e.g. PFN is beneficial in treating inter trochanteric fractures with comminution and loss of lateral buttress. Intramedullary implants have been proven to have increased success rates in subtrochanteric fractures and should be preferred over extramedullary plate fixation systems.
Mittal, Ravi; Banerjee, Sumit
Pulse compression grating fabrication by diffractive proximity photolithography.
We report about a newly devised throughput-scalable fabrication method for high-quality periodic submicron structures. The process is demonstrated for optical transmission gratings in fused silica with a period of 800 nm (1250??lines/mm) to be used in laser pulse compression. The technology is based on an innovative advancement of i-line proximity photolithography performed in a mask aligner. The aerial image is encoded in a rigorously optimized electron-beam-written three-level phase mask which is illuminated by an adapted multipole configuration of incidence angles. In comparison to conventional proximity lithography, the process enables a significantly higher resolution while maintaining a good depth of focus--in contrast to lithography based on direct Talbot-imaging. Details about the grating fabrication process and characterization of fabricated pulse compression grating wafers are presented. The gratings show a diffraction efficiency of 97% at a wavelength of 1030 nm and a wavefront error comparable to gratings fabricated by electron-beam lithography. PMID:24562273
Stuerzebecher, Lorenz; Fuchs, Frank; Harzendorf, Torsten; Zeitner, Uwe D
Proximity to Pollution Sources and Risk of Amphibian Limb Malformation
The cause of limb deformities in wild amphibian populations remains unclear, even though the apparent increase in prevalence of this condition may have implications for human health. Few studies have simultaneously assessed the effect of multiple exposures on the risk of limb deformities. In a cross-sectional survey of 5,264 hylid and ranid metamorphs in 42 Vermont wetlands, we assessed independent risk factors for nontraumatic limb malformation. The rate of nontraumatic limb malformation varied by location from 0 to 10.2%. Analysis of a subsample did not demonstrate any evidence of infection with the parasite Ribeiroia. We used geographic information system (GIS) land-use/land-cover data to validate field observations of land use in the proximity of study wetlands. In a multiple logistic regression model that included land use as well as developmental stage, genus, and water-quality measures, proximity to agricultural land use was associated with an increased risk of limb malformation (odds ratio = 2.26; 95% confidence interval, 1.42¢3.58; p < 0.001). The overall discriminant power of the statistical model was high (C = 0.79). These findings from one of the largest systematic surveys to date provide support for the role of chemical toxicants in the development of amphibian limb malformation and demonstrate the value of an epidemiologic approach to this problem. PMID:16263502
Taylor, Brynn; Skelly, David; Demarchis, Livia K.; Slade, Martin D.; Galusha, Deron; Rabinowitz, Peter M.
Promoter-proximal polyadenylation sites reduce transcription activity
Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site, which in turn causes reduced transcription. Functional depletion of U1 snRNP in the context of the wild-type SD triggers the same CpA event accompanied by decreased RNA levels. Thus, in accordance with recent findings, U1 snRNP can shield premature pA sites. The negative impact of unshielded pA sites on transcription requires promoter proximity, as demonstrated using artificial constructs and supported by a genome-wide data set. Importantly, transcription down-regulation can be recapitulated in a gene context devoid of splice sites by placing a functional bona fide pA site/transcription terminator within ?500 base pairs of the promoter. In contrast, promoter-proximal positioning of a pA site-independent histone gene terminator supports high transcription levels. We propose that optimal communication between a pA site-dependent gene terminator and its promoter critically depends on gene length and that short RNA polymerase II-transcribed genes use specialized termination mechanisms to maintain high transcription levels. PMID:23028143
Andersen, Pia K.; Lykke-Andersen, S°ren; Jensen, Torben Heick
Probing nuclear pore complex architecture with proximity-dependent biotinylation.
Proximity-dependent biotin identification (BioID) is a method for identifying protein associations that occur in vivo. By fusing a promiscuous biotin ligase to a protein of interest expressed in living cells, BioID permits the labeling of proximate proteins during a defined labeling period. In this study we used BioID to study the human nuclear pore complex (NPC), one of the largest macromolecular assemblies in eukaryotes. Anchored within the nuclear envelope, NPCs mediate the nucleocytoplasmic trafficking of numerous cellular components. We applied BioID to constituents of the Nup107-160 complex and the Nup93 complex, two conserved NPC subcomplexes. A strikingly different set of NPC constituents was detected depending on the position of these BioID-fusion proteins within the NPC. By applying BioID to several constituents located throughout the extremely stable Nup107-160 subcomplex, we refined our understanding of this highly conserved subcomplex, in part by demonstrating a direct interaction of Nup43 with Nup85. Furthermore, by using the extremely stable Nup107-160 structure as a molecular ruler, we defined the practical labeling radius of BioID. These studies further our understanding of human NPC organization and demonstrate that BioID is a valuable tool for exploring the constituency and organization of large protein assemblies in living cells. PMID:24927568
Kim, Dae In; Birendra, K C; Zhu, Wenhong; Motamedchaboki, Khatereh; Doye, Valķrie; Roux, Kyle J
Modulation of hydrophobic interactions by proximally immobilized ions
NASA Astrophysics Data System (ADS)
The structure of water near non-polar molecular fragments or surfaces mediates the hydrophobic interactions that underlie a broad range of interfacial, colloidal and biophysical phenomena. Substantial progress over the past decade has improved our understanding of hydrophobic interactions in simple model systems, but most biologically and technologically relevant structures contain non-polar domains in close proximity to polar and charged functional groups. Theories and simulations exploring such nanometre-scale chemical heterogeneity find it can have an important effect, but the influence of this heterogeneity on hydrophobic interactions has not been tested experimentally. Here we report chemical force microscopy measurements on alkyl-functionalized surfaces that reveal a dramatic change in the surfaces' hydrophobic interaction strengths on co-immobilization of amine or guanidine groups. Protonation of amine groups doubles the strength of hydrophobic interactions, and guanidinium groups eliminate measurable hydrophobic interactions in all pH ranges investigated. We see these divergent effects of proximally immobilized cations also in single-molecule measurements on conformationally stable ?-peptides with non-polar subunits located one nanometre from either amine- or guanidine-bearing subunits. Our results demonstrate the importance of nanometre-scale chemical heterogeneity, with hydrophobicity not an intrinsic property of any given non-polar domain but strongly modulated by functional groups located as far away as one nanometre. The judicious placing of charged groups near hydrophobic domains thus provides a strategy for tuning hydrophobic driving forces to optimize molecular recognition or self-assembly processes.
Ma, C. Derek; Wang, Chenxuan; Acevedo-Vķlez, Claribel; Gellman, Samuel H.; Abbott, Nicholas L.
Modulation of hydrophobic interactions by proximally immobilized ions.
The structure of water near non-polar molecular fragments or surfaces mediates the hydrophobic interactions that underlie a broad range of interfacial, colloidal and biophysical phenomena. Substantial progress over the past decade has improved our understanding of hydrophobic interactions in simple model systems, but most biologically and technologically relevant structures contain non-polar domains in close proximity to polar and charged functional groups. Theories and simulations exploring such nanometre-scale chemical heterogeneity find it can have an important effect, but the influence of this heterogeneity on hydrophobic interactions has not been tested experimentally. Here we report chemical force microscopy measurements on alkyl-functionalized surfaces that reveal a dramatic change in the surfaces' hydrophobic interaction strengths on co-immobilization of amine or guanidine groups. Protonation of amine groups doubles the strength of hydrophobic interactions, and guanidinium groups eliminate measurable hydrophobic interactions in all pH ranges investigated. We see these divergent effects of proximally immobilized cations also in single-molecule measurements on conformationally stable ?-peptides with non-polar subunits located one nanometre from either amine- or guanidine-bearing subunits. Our results demonstrate the importance of nanometre-scale chemical heterogeneity, with hydrophobicity not an intrinsic property of any given non-polar domain but strongly modulated by functional groups located as far away as one nanometre. The judicious placing of charged groups near hydrophobic domains thus provides a strategy for tuning hydrophobic driving forces to optimize molecular recognition or self-assembly processes. PMID:25592540
Ma, C Derek; Wang, Chenxuan; Acevedo-Vķlez, Claribel; Gellman, Samuel H; Abbott, Nicholas L
Measurements of the dc Josephson current in proximity systems
Junctions modeled as [ital S]-[ital N]/[ital I]/[ital S] and [ital S]-[ital N]/[ital I]/[ital N]-[ital S] proximity systems (where [ital S], [ital I], and [ital N] indicate a superconductor, an insulator, and a normal metal, respectively) are widely discussed in literature from both the experimental and theoretical point of view. In the present paper experimental aspects concerning Nb/Nb junctions including a proximity bilayer are considered. Nb-[ital M]/[ital I]/Nb and [ital M]-Nb/[ital I]/Nb structures (where [ital M] is a normal metal, a semimetal, or a superconductor) are investigated by using a semimetal (bismuth) and a superconductor (aluminum) as the [ital M] layer. In particular, how the deposition of a back layer influences the behavior of Nb/[ital I]/Nb high-quality junctions is discussed, focusing the interest on measurements of the temperature dependence of the maximum dc Josephson current. Experimental data are discussed in the framework of Kresin's theoretical calculations based on the thermodynamic Green's function method.
Camerlingo, C.; Monaco, R.; Ruggiero, B.; Russo, M. (Istituto di Cibernetica del Consiglio Nazionale delle Ricerche, I-80072 Arco Felice (Napoli) (Italy)); Testa, G. (Istituto Nazionale di Fisica Nucleare, I-80125 Napoli (Italy))
Probing nuclear pore complex architecture with proximity-dependent biotinylation
Proximity-dependent biotin identification (BioID) is a method for identifying protein associations that occur in vivo. By fusing a promiscuous biotin ligase to a protein of interest expressed in living cells, BioID permits the labeling of proximate proteins during a defined labeling period. In this study we used BioID to study the human nuclear pore complex (NPC), one of the largest macromolecular assemblies in eukaryotes. Anchored within the nuclear envelope, NPCs mediate the nucleocytoplasmic trafficking of numerous cellular components. We applied BioID to constituents of the Nup107¢160 complex and the Nup93 complex, two conserved NPC subcomplexes. A strikingly different set of NPC constituents was detected depending on the position of these BioID-fusion proteins within the NPC. By applying BioID to several constituents located throughout the extremely stable Nup107¢160 subcomplex, we refined our understanding of this highly conserved subcomplex, in part by demonstrating a direct interaction of Nup43 with Nup85. Furthermore, by using the extremely stable Nup107¢160 structure as a molecular ruler, we defined the practical labeling radius of BioID. These studies further our understanding of human NPC organization and demonstrate that BioID is a valuable tool for exploring the constituency and organization of large protein assemblies in living cells. PMID:24927568
Kim, Dae In; KC, Birendra; Zhu, Wenhong; Motamedchaboki, Khatereh; Doye, Valķrie; Roux, Kyle J.
Vision-based Proximity Detection in Retinal Surgery
In retinal surgery, surgeons face difficulties such as indirect visualization of surgical targets, physiological tremor and lack of tactile feedback, which increase the risk of retinal damage caused by incorrect surgical gestures. In this context, intra-ocular proximity sensing has the potential to overcome current technical limitations and increase surgical safety. In this paper we present a system for detecting unintentional collisions between surgical tools and the retina using the visual feedback provided by the opthalmic stereo microscope. Using stereo images, proximity between surgical tools and the retinal surface can be detected when their relative stereo disparity is small. For this purpose, we developed a system comprised of two modules. The first is a module for tracking the surgical tool position on both stereo images. The second is a disparity tracking module for estimating a stereo disparity map of the retinal surface. Both modules were specially tailored for coping with the challenging visualization conditions in retinal surgery. The potential clinical value of the proposed method is demonstrated by extensive testing using a silicon phantom eye and recorded rabbit in vivo data. PMID:22692869
Richa, Rogķrio; Balicki, Marcin; Sznitman, Raphael; Meisner, Eric; Taylor, Russell; Hager, Gregory
Orion Handling Qualities During ISS Proximity Operations and Docking
NASA Technical Reports Server (NTRS)
NASA's Orion spacecraft is designed to autonomously rendezvous and dock with many vehicles including the International Space Station. However, the crew is able to assume manual control of the vehicle s attitude and flight path. In these instances, Orion must meet handling qualities requirements established by NASA. Two handling qualities assessments were conducted at the Johnson Space Center to evaluate preliminary designs of the vehicle using a six degree of freedom, high-fidelity guidance, navigation, and control simulation. The first assessed Orion s handling qualities during the last 20 ft before docking, and included both steady and oscillatory motions of the docking target. The second focused on manual acquisition of the docking axis during the proximity operations phase and subsequent station-keeping. Cooper-Harper handling qualities ratings, workload ratings and comments were provided by 10 evaluation pilots for the docking study and 5 evaluation pilots for the proximity operations study. For the docking task, both cases received 90% Level 1 (satisfactory) handling qualities ratings, exceeding NASA s requirement. All ratings for the ProxOps task were Level 1. These evaluations indicate that Orion is on course to meet NASA's handling quality requirements for ProxOps and docking.
Stephens, John-Paul; Vos, Gordon A.; Bilimoria, Karl D.; Mueller, Eric R.; Brazzel, Jack; Spehar, Pete
Cancer risk and residential proximity to cranberry cultivation in Massachusetts.
OBJECTIVES: This study evaluated the relationship between cancer risk and residential proximity to cranberry cultivation. METHODS: A population-based case-control study was conducted. Cases, diagnosed during 1983 through 1986 among residents of the Upper Cape Cod area of Massachusetts, involved incident cancers of the lung (n = 252), breast (n = 265), colon-rectum (n = 326), bladder (n = 63), kidney (n = 35), pancreas (n = 37), and brain (n = 37), along with leukemia (n = 35). Control subjects were randomly selected from among telephone subscribers (n = 184), Medicare beneficiaries (n = 464), and deceased individuals (n = 723). RESULTS: No meaningful increases in risk were seen for any of the cancer sites except for the brain. When latency was considered, subjects who had ever lived within 2600 ft (780 m) of a cranberry bog had a twofold increased risk of brain cancer overall (95% confidence interval [CI] = 0.8, 4.9) and a 6.7-fold increased risk of astrocytoma (95% CI = 1.6, 27.8). CONCLUSIONS: Residential proximity to cranberry bog cultivation was not associated with seven of the eight cancers investigated; however, an association was observed with brain cancer, particularly astrocytoma. Larger, more detailed studies are necessary to elucidate this relationship. PMID:8806382
Aschengrau, A; Ozonoff, D; Coogan, P; Vezina, R; Heeren, T; Zhang, Y
Lung cancer mortality and residential proximity to industry.
A potential causal relationship has been suggested by other studies between air pollution and lung cancer. To attempt to define the risk of lung cancer associated with residential proximity to industry by type in Louisiana, lung cancer deaths occurring between 1960 and 1975 in residents of 20 parishes were compared to controls matched on age, sex, year of death and parish of residence. The comparisons were limited to cases (N = 1418) and controls (N = 1429) with known length of exposure to and residing within 0.99 mile (exposed and 1.0 to 3.0 miles (unexposed) radius of an industry type. Of the 13 industry types evaluated, the petroleum and chemical industries showed the highest consistent elevations in risk associated with closeness of residence to industry, whereas possible risks shown for food, grain, canning, and paper industries are less defined. For the petroleum industry, the risk was demonstrated in the group with 10 or more years of residential exposure to the industry in question. For the chemical industry, the residential risk was found in people employed in low risk occupations, who were exposed to large individual industries and was independent of length of exposure as determined for less or more than ten years, (RR = 4.5). The results suggest that residential proximity to petrochemical industries may make a contribution to the lung cancer mortality in Louisiana. PMID:7140691
Gottlieb, M S; Shear, C L; Seale, D B
Digital Image Enhancement Improves Diagnosis of Nondisplaced Proximal Femur Fractures
Today most emergency room radiographs are computerized, making digital image enhancement a natural advancement to improve fracture diagnosis. We compared the diagnosis of nondisplaced proximal femur fractures using four different image enhancement methods using standard DICOM (Digital Imaging and Communications in Medicine) after window-leveling optimization. Twenty-nine orthopaedic residents and specialists reviewed 28 pelvic images consisting of 25 occult proximal femur fractures and three images with no fracture, using four different image filters and the original DICOM image. For intertrochanteric fractures, the Retinex filter outperforms the other filters and the original image with a correct fracture type diagnosis rate of 50.6%. The Retinex filter also performs well for diagnosis of other fracture types. The Retinex filter had an interobserver agreement index of 53.5%, higher than the other filters. Sensitivity of fracture diagnosis increased to 85.2% when the Retinex filter was combined with the standard DICOM image. Correct fracture type diagnosis per minute for the Retinex filter was 1.43, outperforming the other filters. The Retinex filter may become a valuable tool in clinical settings for diagnosing fractures. Level of Evidence: Level I, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18791776
Herman, Amir; Nathaniel, Ram; Rappaport, Dan; Chechik, Aharon
Evidence for a role of claudin 2 as a proximal tubular stress responsive paracellular water channel.
Claudins are the major proteins of the tight junctions and the composition of claudin subtypes is decisive for the selective permeability of the paracellular route and thus tissue specific function. Their regulation is complex and subject to interference by several factors, including oxidative stress. Here we show that exposure of cultured human proximal tubule cells (RPTEC/TERT1) to the immunosuppressive drug cyclosporine A (CsA) induces an increase in transepithelial electrical resistance (TEER), a decrease in dome formation (on solid growth supports) and a decrease in water transport (on microporous growth supports). In addition, CsA induced a dramatic decrease in the mRNA for the pore forming claudins -2 and -10, and the main subunits of the Na(+)/K(+) ATPase. Knock down of claudin 2 by shRNA had no discernable effect on TEER or dome formation but severely attenuated apical to basolateral water reabsorption when cultured on microporous filters. Generation of an osmotic gradient in the basolateral compartment rescued water transport in claudin 2 knock down cells. Inhibition of Na(+)/K(+) ATPase with ouabain prevented dome formation in both cell types. Taken together these results provide strong evidence that dome formation is primarily due to transcellular water transport following a solute osmotic gradient. However, in RPTEC/TERT1 cells cultured on filters under iso-osmotic conditions, water transport is primarily paracellular, most likely due to local increases in osmolarity in the intercellular space. In conclusion, this study provides strong evidence that claudin 2 is involved in paracellular water transport and that claudin 2 expression is sensitive to compound induced cellular stress. PMID:24907557
Wilmes, Anja; Aschauer, Lydia; Limonciel, Alice; Pfaller, Walter; Jennings, Paul
The proximate, nutritional, and antinutritional compositions of the raw, cooked, and roasted samples of four Nigerian indigenous seeds-Sphenostylis stenocarpa, Pentaclethra macrophylla, Mucuna flagellipes, and Citrullus colocynthis-were evaluated. Also estimated were zinc and divalent cation bioavailability of the seeds using millimolar ratios/kg dry weight of [calcium]/[phytate], [phytate]/[zinc], [calcium][phytate]/[Zn], and [phytate]/[total phosphorus]. The results obtained revealed that the seeds of P. macrophylla and C. colocynthis had high protein and lipid levels. All the seeds were also found to have high energy value and low moisture content. Mineral analysis showed the presence of Na, K, Ca, and Mg in appreciable quantities and Zn, I, Fe, and Se in minute quantities. Antinutritional analyses indicated the presence of traces of tannin, oxalate, phytate, saponin, and cyanide in the samples. The various processing techniques had significant (P???.05) effects on the measured parameters. The calculated [Ca][phytate]/[Zn] molar ratios revealed that these seeds had values above the critical level of 0.5?mL/kg, thus indicating reduced bioavailability of zinc. In view of the high nutrient contents, low antinutritional contents after processing, and their superabundance, these seeds could be cheap nutrient sources. The implications of these findings with regards to food security are enormous. PMID:20828321
Ojiako, Okey A; Ogbuji, Chiza A; Agha, Ngozi C; Onwuliri, Viola A
Proximate Composition, Amino Acid, Mineral, and Heavy Metal Content of Dried Laver
Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and ?-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals. PMID:24471123
Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull
Expression of OAT1 and OAT3 in differentiating proximal tubules of the mouse kidney.
Organic anion transporter 1 (OAT1) and OAT3 in the proximal tubules (PT) of the kidney play important roles in the elimination of harmful endogenous compounds and xenobiotics from the body. We investigated the temporal and spatial expression of OAT1 and OAT3 in the differentiating PT in mouse kidney. Ontogenic expression of OAT1 and OAT3 was investigated by immunohistochemical analysis. The S1, S2, and S3 segments of the PT were identified using antibodies to aquaporin 1 (AQP1), Na+-HCO3- cotransporter 1 (kNBC1), and AQP4. OAT1 immunoreactivity was first detected at PT in the inner cortex of 15-day-old fetuses (F15) and in the outer cortex of 7-day old pups. OAT3 was first observed in the distal tubule of F14 and in S2 segment of the PT of F16 and in S1 and S3 segments around the time of birth; expression increased through postpartum day 21. The ontogenic pattern of expression of OAT1 and OAT3 in the differentiating PT suggests that both transporters may function in the S2 segment in the fetus, but not until after birth in S1 and S3 segments. PMID:19924639
Hwang, Jin-Sun; Park, Eun-Young; Kim, Wan-Young; Yang, Chul-Woo; Kim, Jin
Putative interaction of brush cells with bicarbonate secreting cells in the proximal corpus mucosa
The gastric epithelium is protected from the highly acidic luminal content by alkaline mucus which is secreted from specialized epithelial cells. In the stomach of mice strong secretion of alkaline fluid was observed at the ōgastric groove,ö the border between corpus and fundus mucosa. Since this region is characterized by numerous brush cells it was proposed that these cells might secrete alkaline solution as suggested for brush cells in the bile duct. In fact, it was found that in this region multiple cells express elements which are relevant for the secretion of bicarbonate, including carbonic anhydrase (CAII), the cystic fibrosis transmembrane conductance regulator (CFTR) and the Na+/H+ exchanger (NHE1). However, this cell population was distinct from brush cells which express the TRP-channel TRPM5 and are considered as putative sensory cells. The location of both cell populations in close proximity implies the possibility for a paracrine interaction. This view was substantiated by the finding that brush cells express prostaglandin synthase-1 (COX-1) and the neighboring cells a specific receptor type for prostaglandins. The notion that brush cells may be able to sense a local acidification was supported by the observation that they express the channel PKD1L3 which contributes to the acid responsiveness of gustatory sensory cells. The results support the concept that brush cells may sense the luminal content and influence via prostaglandins the secretion of alkaline solution. PMID:23874305
Eberle, Julia Anna-Maria; M³ller-Roth, Kai L.; Widmayer, Patricia; Chubanov, Vladimir; Gudermann, Thomas; Breer, Heinz
Cell surface proteins are internalized into the cell through endocytosis and either degraded within lysosomes or recycled back to the plasma membrane. While perturbations in endosomal internalization are known to modulate renal function, it is not known whether similar alterations in recycling affect renal function. Rififylin is a known regulator of endocytic recycling with E3 ubiquitin protein ligase activity. In this study, using two genetically similar strains, the Dahl Salt-sensitive rat and an S.LEW congenic strain, which had allelic variants within a?330?kb segment containing rififylin, we tested the hypothesis that alterations in endosomal recycling affect renal function. The congenic strain had 1.59-fold higher renal expression of rififylin. Transcriptome analysis indicated that components of both endocytosis and recycling were upregulated in the congenic strain. Transcription of Atp1a1 and cell surface content of the protein product of Atp1a1, the alpha subunit of Na+K+ATPase were increased in the proximal tubules from the congenic strain. Because rififylin does not directly regulate endocytosis and it is also a differentially expressed gene within the congenic segment, we reasoned that the observed alterations in the transcriptome of the congenic strain constitute a feedback response to the primary functional alteration of recycling caused by rififylin. To test this, recycling of transferrin was studied in isolated proximal tubules. Recycling was significantly delayed within isolated proximal tubules of the congenic strain, which also had a higher level of polyubiquitinated proteins and proteinuria compared with S. These data provide evidence to suggest that delayed endosomal recycling caused by excess of rififylin indirectly affects endocytosis, enhances intracellular protein polyubiquitination and contributes to proteinuria. PMID:22891072
Gopalakrishnan, Kathirvel; Kumarasamy, Sivarajan; Yan, Yanling; Liu, Jiang; Kalinoski, Andrea; Kothandapani, Anbarasi; Farms, Phyllis; Joe, Bina
Proximal microdeletions and microduplications of 1q21.1 contribute to variable abnormal phenotypes
Chromosomal band 1q21.1 can be divided into two distinct regions, proximal and distal, based on segmental duplications that mediate recurrent rearrangements. Microdeletions and microduplications of the distal region within 1q21.1, which are susceptibility factors for a variety of neurodevelopmental phenotypes, have been more extensively studied than proximal microdeletions and microduplications. Proximal microdeletions are known as a susceptibility factor for thrombocytopenia-absent radius (TAR) syndrome, but it is unclear if these proximal microdeletions have other phenotypic consequences. Therefore, to elucidate the clinical significance of rearrangements of the proximal 1q21.1 region, we evaluated the phenotypes in patients identified with 1q21.1 rearrangements after referral for clinical microarray testing. We report clinical information for 55 probands with copy number variations (CNVs) involving proximal 1q21.1: 22 microdeletions and 20 reciprocal microduplications limited to proximal 1q21.1 and 13 microdeletions that include both the proximal and distal regions. Six individuals with proximal microdeletions have TAR syndrome. Three individuals with proximal microdeletions and two individuals with larger microdeletions of proximal and distal 1q21.1 have a æpartial' TAR phenotype. Furthermore, one subject with TAR syndrome has a smaller, atypical deletion, narrowing the critical deletion region for the syndrome. Otherwise, phenotypic features varied among individuals with these microdeletions and microduplications. The recurrent, proximal 1q21.1 microduplications are enriched in our population undergoing genetic testing compared with control populations. Therefore, CNVs in proximal 1q21.1 can be a contributing factor for the development of abnormal phenotypes in some carriers. PMID:22317977
Rosenfeld, Jill A; Traylor, Ryan N; Schaefer, G Bradley; McPherson, Elizabeth W; Ballif, Blake C; Klopocki, Eva; Mundlos, Stefan; Shaffer, Lisa G; Aylsworth, Arthur S
Mechanism of ?-Conotoxin PIIIA Binding to the Voltage-Gated Na+ Channel NaV1.4
Several subtypes of voltage-gated Na+ (NaV) channels are important targets for pain management. ?-Conotoxins isolated from venoms of cone snails are potent and specific blockers of different NaV channel isoforms. The inhibitory effect of ?-conotoxins on NaV channels has been examined extensively, but the mechanism of toxin specificity has not been understood in detail. Here the known structure of ?-conotoxin PIIIA and a model of the skeletal muscle channel NaV1.4 are used to elucidate elements that contribute to the structural basis of ?-conotoxin binding and specificity. The model of NaV1.4 is constructed based on the crystal structure of the bacterial NaV channel, NaVAb. Six different binding modes, in which the side chain of each of the basic residues carried by the toxin protrudes into the selectivity filter of NaV1.4, are examined in atomic detail using molecular dynamics simulations with explicit solvent. The dissociation constants (Kd) computed for two selected binding modes in which Lys9 or Arg14 from the toxin protrudes into the filter of the channel are within 2 fold; both values in close proximity to those determined from dose response data for the block of NaV currents. To explore the mechanism of PIIIA specificity, a double mutant of NaV1.4 mimicking NaV channels resistant to ?-conotoxins and tetrodotoxin is constructed and the binding of PIIIA to this mutant channel examined. The double mutation causes the affinity of PIIIA to reduce by two orders of magnitude. PMID:24676211
Chen, Rong; Robinson, Anna; Chung, Shin-Ho
Objective to design a flow model to determine whether and why increased proximal neck angulation correlates with increased risk of proximal perigraft endoleak (PPE) flow. Methods a tapered stent-graft (Gianturco stent + Dacron) was deployed with proximal and distal necks made of silicone. The amount of PPE was measured over 30-s periods while the angulation of the proximal neck was
J.-N Albertini; J. A Macierewicz; S. W Yusuf; P. W Wenham; B. R Hopkinson
A series of experiments were conducted to examine the possible effects of subcutaneous administration of the synthetic glucocorticoid dexamethasone (100 micrograms/day per 100 g body wt.) on the lipid fluidity and lipid composition of rat proximal-small-intestinal brush-border membranes. After 4 days of treatment, membranes and their liposomes prepared from treated animals possessed a greater fluidity than did their control (diluent, 0.9% NaCl) counterparts, as assessed by steady-state fluorescence-polarization techniques using several different fluorophores. Examination of the effects of temperature on the anisotropy values of 1,6-diphenylhexa-1,3,5-triene, using Arrhenius plots, moreover, revealed that the mean break-point temperatures of the treated preparations were approx. 3-4 degrees C lower than those of their control-preparation counterparts. Changes in the sphingomyelin/phosphatidylcholine (PC) molar ratio as well as in certain of the fatty acids of the PC fraction of treated membranes, secondary to alterations in membrane PC levels and in lysophosphatidylcholine acyltransferase activities respectively, were also noted after dexamethasone administration. These compositional alterations appeared to be responsible, at least in part, for the differences in fluidity noted between treated and control plasma membranes. These results therefore demonstrate that dexamethasone administration can modulate the lipid fluidity and lipid composition of rat proximal-small-intestinal brush-border membranes. PMID:3435460
Brasitus, T A; Dudeja, P K; Dahiya, R; Halline, A
The oblique proximal phalangeal osteotomy in the correction of hallux valgus
An oblique proximal phalangeal osteotomy is introduced as an alternative to the Akin procedure for the treatment of hallux valgus. It consists of a single oblique osteotomy directed from proximal-dorsal to plantar-distal. A retrospective review of 32 patients who underwent 36 oblique proximal osteotomies is presented. The mean follow-up was 11 months (range, 3 to 21 months). Pre- and postoperative
Michael M Cohen
Proximal Sensor Data from Routine Dual-Sensor Esophageal pH Monitoring Is Often Inaccurate
Dual-sensor esophageal pH monitoring is routinely used to diagnose GERD. However, the proximal sensor may not be in proximal esophagus in patients with shortened esophagi. Our objective was to determine how often the proximal sensor was misplaced and to determine the effect on pH monitoring. Superior margins of the upper and lower esophageal sphincters (UES and LES) were determined prospectively
Matt McCollough; Abdul Jabbar; Robert Cacchione; Jeff W. Allen; Steve Harrell; John M. Wo
Proximal row carpectomy for chronic unreduced perilunate dislocations.
We evaluated the results of proximal row carpectomy (PRC) for unreduced perilunate dislocation in 6 patients. The average period from the injury to the operation was 24 weeks. The modified Mayo wrist score was used for clinical evaluation. Radiological evaluation was based on the radius-capitate alignment. Pain disappeared in 4 cases; mild pain during activity persisted in 2 cases. The average flexion-extension are was 59% of the values on the unaffected side. The average grip strength was 72% of the unaffected side, and the average modified Mayo wrist score was 71 points. Three patients showed favourable radius-capitate alignment, while the other 3 patients showed poor radius-capitate alignment on the radiographs. The postoperative radius-capitate alignment was related to the preoperative position of the capitate on the lateral view. Those with poor radius-capitate alignment tended to obtain lower scores compared to those with favourable alignment. PMID:22308621
Shinohara, Takaaki; Tatebe, Masahiro; Okui, Nobuyuki; Yamamoto, Michiro; Kurimoto, Shigeru; Hirata, Hitoshi
Proximal-point method for finite element model updating problem
NASA Astrophysics Data System (ADS)
The problem of finding the optimal approximation to analytical stiffness matrix modeled by the finite element method is considered in this paper. Desired matrix properties, including satisfaction of the dynamic equation, symmetry, positive semidefiniteness and physical connectivity, are imposed as side constraints of the minimization problem. To the best of the author's knowledge, the finite element model updating problem containing all these constraints simultaneously has not been proposed in the literature earlier. By partial Lagrangian multipliers technique, the optimization problem is transformed into a matrix linear variational inequality and the proximal-point method is first used to solve the equivalent problem. The results of numerical examples show that the proposed method works well even for incomplete measured data.
Yuan, Quan
Proximal gastric motility functions are normal in severe obesity.
The role of altered gastric motor functions for the development of obesity is still unclear. In this study, we investigated whether severe obesity is related to gastric dysfunctions or to abnormal perception in response to distension. 31 obese patients and 20 healthy volunteers were studied using an electronic barostat. Basal gastric tone, gastric accommodation, and perception in response to distension were not altered in obese patients. The median minimal distending pressure, reflecting the intra-abdominal pressure, was significantly elevated in obese patients, being 12 versus 7 mm Hg, respectively (p < 0.0001). We conclude that the proximal gastric motility, including perception and accommodation in response to intragastric distension, is not impaired in severe obesity. Whether disturbances of gastric reflex relaxation in response to a meal are involved in the pathogenesis of obesity remains to be established. PMID:9144300
Klatt, S; Pieramico, O; G³thner, C; Ditschuneit, H H; Glasbrenner, B; Beckh, K; Adler, G
Electrical capacitance tomography using an accelerated proximal gradient algorithm
NASA Astrophysics Data System (ADS)
Image reconstruction in electrical capacitance tomography requires a solution of an ill-posed inverse problem. This paper applies an accelerated proximal gradient (APG) singular value thresholding algorithm, which is originally proposed for the matrix completion problem, to image two-phase flow. Aiming to improve the image quality, a nuclear norm-based regularization technique is adopted to treat the ill-posedness of the inverse problem, and a simple updating technique is used to update the sensitivity matrix. Both typical and complicated distributions (e.g., "sun-rise" and cross-shape), have been examined based on a 16-electrode configuration. The results showed that the APG algorithm with updated sensitivity matrix could produce higher quality images when compared to the algorithm based on the typical sensitivity matrix. Both simulation and experiment results indicate that the algorithm developed has been able to achieve good quality reconstructed images with relativity fast computation speed for the cases tested in this paper.
Xue, Qian; Wang, Huaxiang; Cui, Ziqiang; Yang, Chengyi
Proximal and point detection of contaminated surfaces using Raman spectroscopy
NASA Astrophysics Data System (ADS)
We are actively investigating the use of Raman spectroscopy for proximal standoff detection of chemicals and explosive materials on surfaces. These studies include Raman Chemical Imaging of contaminated fingerprints for forensic attribution and the assessments of commercial handheld or portable Raman instruments operating with near-infrared (IR) as well as ultraviolet (UV) laser excitation specifically developed for on-the-move reconnaissance of chemical contamination. As part of these efforts, we have measured the Raman cross sections of chemical agents, toxic industrial chemicals, and explosives from the UV to NIR. We have also measured and modeled the effect interrogation angle has on the Raman return from droplets on man-made surfaces. Realistic droplet distributions have been modeled and tested against variations in surface scan patterns and laser spot size for determining the optimum scan characteristics for detection of relevant surface contamination.
Guicheteau, Jason A.; Christesen, Steven D.; Tripathi, Ashish; Emmons, Erik D.; Wilcox, Phillip G.; Emge, Darren K.; Pardoe, Ian J.; Fountain, Augustus W., III
Transition Metal Dichalcogenide Growth via Close Proximity Precursor Supply.
Reliable chemical vapour deposition (CVD) of transition metal dichalcogenides (TMDs) is currently a highly pressing research field, as numerous potential applications rely on the production of high quality films on a macroscopic scale. Here, we show the use of liquid phase exfoliated nanosheets and patterned sputter deposited layers as solid precursors for chemical vapour deposition. TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup. A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented. Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, scanning electron microscopy and electrical transport measurements reveal the high quality of the TMD samples produced. Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components. PMID:25487822
O'Brien, Maria; McEvoy, Niall; Hallam, Toby; Kim, Hye-Young; Berner, Nina C; Hanlon, Damien; Lee, Kangho; Coleman, Jonathan N; Duesberg, Georg S
Rendezvous, proximity operations and capture quality function deployment report
NASA Technical Reports Server (NTRS)
Rendezvous, Proximity Operations, and Capture (RPOC) is a missions operations area which is extremely important to present and future space initiatives and must be well planned and coordinated. To support this, a study team was formed to identify a specific plan of action using the Quality Function Deployment (QFD) process. This team was composed of members from a wide spectrum of engineering and operations organizations which are involved in the RPOC technology area. The key to this study's success is an understanding of the needs of potential programmatic customers and the technology base available for system implementation. To this end, the study team conducted interviews with a variety of near term and future programmatic customers and technology development sponsors. The QFD activity led to a thorough understanding of the needs of these customers in the RPOC area, as well as the relative importance of these needs.
Lamkin, Stephen L. (editor)
Proximity sensors based on ball-lensed optical fibers
NASA Astrophysics Data System (ADS)
Reflective sensors involving optical fibers are very popular due to low cost and EMI insensitive. In this paper, a new concept is described regarding proximity sensors based on ball-lensed optical fibers (PSBBOF). Two types of sensors are presented: (1) Type A with one transmitting and four receiving optical fibers and (2) Type B with one transmitting and eight receiving optical fibers. In both PSBBOF types ball-lensed optical fibers are used as a receiving line. Sensitive of both PSBBOF is compared to sensitive of sensors with the same configurations, but involving cleaved optical fibers. All developed sensors were tested at two wavelengths: 850 nm and 1300 nm. As a refractive surface the silicon wafer was used.
Guzowski, Bartlomiej; Cywinski, Marek; Lakomski, Mateusz
Transition Metal Dichalcogenide Growth via Close Proximity Precursor Supply
Reliable chemical vapour deposition (CVD) of transition metal dichalcogenides (TMDs) is currently a highly pressing research field, as numerous potential applications rely on the production of high quality films on a macroscopic scale. Here, we show the use of liquid phase exfoliated nanosheets and patterned sputter deposited layers as solid precursors for chemical vapour deposition. TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup. A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented. Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, scanning electron microscopy and electrical transport measurements reveal the high quality of the TMD samples produced. Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components. PMID:25487822
O'Brien, Maria; McEvoy, Niall; Hallam, Toby; Kim, Hye-Young; Berner, Nina C.; Hanlon, Damien; Lee, Kangho; Coleman, Jonathan N.; Duesberg, Georg S.
Condensate-free superfluidity induced by frustrated proximity effect
Since the discovery of superfluidity in He4 and Landau's phenomenological theory, the relationship between Bose condensation and superfluidity has been intensely debated. He4 is known by now to be both superfluid and condensed at low temperature, and more generally, in dimension D \\geq 2, all superfluid bosonic models realized in experiments are condensed in their ground state. Recent examples include ultracold bosonic atoms trapped in an optical lattice or effective bosons describing magnetic excitations in quantum magnets. In this paper, it is shown that a 2D gas of bosons which is superfluid but not condensed at T=0 can be achieved by populating a layer through a frustrated proximity effect from a superfluid reservoir. This bosonic fluid is characterized by specific scaling laws and incommensurate correlations. This leads to several predictions for the quantum antiferromagnet BaCuSi2O6 (Han purple) in a magnetic field, a good candidate to realize this novel state of matter.
Laflorencie, Nicolas
Endovascular Treatment of Proximal Anastomotic Aneurysms After Aortic Prosthetic Reconstruction
Purpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudoaneurysms.Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8-15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n = 1), bifurcated graft (n = 1)]. In one patient an uni iliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.
Tiesenhausen, Kurt [Department of Vascular Surgery, University Hospital Graz, Auenbruggerplatz 29, A-8036 Graz (Austria); Hausegger, Klaus A.; Tauss, Josef [Department of Radiology, University Hospital Graz, Auenbruggerplatz 29, A-8036 Graz (Austria); Amann, Wilfried; Koch, Guenter [Department of Vascular Surgery, University Hospital Graz, Auenbruggerplatz 29, A-8036 Graz (Austria)
Endovascular treatment of proximal arsastomotic aneurysms after aortic prosthetic reconstruction
Purpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudo-aneurysms.Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8-15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n=1), bifurcated graft (n=s1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.
Tiesenhausen, Kurt [University Hospital Graz, Department of Vascular Surgery (Austria); Hausegger, Klaus A.; Tauss, Josef [University Hospital Graz, Department of Radiology (Austria); Amann, Wilfried; Koch, Guenter [University Hospital Graz, Department of Vascular Surgery (Austria)
Orion Rendezvous, Proximity Operations, and Docking Design and Analysis
NASA Technical Reports Server (NTRS)
The Orion vehicle will be required to perform rendezvous, proximity operations, and docking with the International Space Station (ISS) and the Earth Departure Stage (EDS)/Lunar Landing Vehicle (LLV) stack in Low Earth Orbit (LEO) as well as with the Lunar Landing Vehicle in Low Lunar Orbit (LLO). The RPOD system, which consists of sensors, actuators, and software is being designed to be flexible and robust enough to perform RPOD with different vehicles in different environments. This paper will describe the design and the analysis which has been performed to date to allow the vehicle to perform its mission. Since the RPOD design touches on many areas such as sensors selection and placement, trajectory design, navigation performance, and effector performance, it is inherently a systems design problem. This paper will address each of these issues in order to demonstrate how the Orion RPOD has been designed to accommodate and meet all the requirements levied on the system.
D'Souza, Christopher; Hanak, F. Chad; Spehar, Pete; Clark, Fred D.; Jackson, Mark
Proximity fingerprint of s{plus_minus} superconductivity.
We suggest a straightforward and unambiguous test to identify possible opposite signs of the superconducting order parameter in different bands proposed for iron-based superconductors (s{sub {+-}}-state). We consider the proximity effect in a weakly coupled sandwich composed of a s{sub {+-}}-superconductor and a thin layer of the s-wave superconductor. In such system the s-wave order parameter is coupled differently with different s{sub {+-}}-gaps and it typically aligns with one of these gaps. This forces the other s{sub {+-}}-gap to be anti-aligned with the s-wave gap. In such situation the aligned band induces a peak in the s-wave density of states (DoS), while the anti-aligned band induces a dip. Observation of such contact-induced negative feature in the s-wave DoS would provide a definite proof for s{sub {+-}}-superconductivity.
Koshelev, A. E.; Stanev, V. (Materials Science Division)
Automobile proximity and indoor residential concentrations of BTEX and MTBE
Attached garages have been identified as important sources of indoor residential air pollution. However, the literature lacks information on how the proximity of cars to the living area affects indoor concentrations of gasoline-related compounds, and the origin of these pollutants. We analyzed data from the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study and evaluated 114 residences with cars in an attached garage, detached garage or carport, or without cars. Results indicate that homes with cars in attached garages were affected the most. Concentrations in homes with cars in detached garages and residences without cars were similar. The contribution from gasoline-related sources to indoor benzene and MTBE concentrations appeared to be dominated by car exhaust, or a combination of tailpipe and gasoline vapor emissions. Residing in a home with an attached garage could lead to benzene exposures ten times higher than exposures from commuting in heavy traffic.
Corsi, Dr. Richard [University of Texas, Austin; Morandi, Dr. Maria [University of Texas Health Science Center, Houston; Siegel, Dr. Jeffrey [University of Texas, Austin; Hun, Diana E [ORNL
Analytic-domain lens design with proximate ray tracing.
We have developed an alternative approach to optical design which operates in the analytical domain so that an optical designer works directly with rays as analytical functions of system parameters rather than as discretely sampled polylines. This is made possible by a generalization of the proximate ray tracing technique which obtains the analytical dependence of the rays at the image surface (and ray path lengths at the exit pupil) on each system parameter. The resulting method provides an alternative direction from which to approach system optimization and supplies information which is not typically available to the system designer. In addition, we have further expanded the procedure to allow asymmetric systems and arbitrary order of approximation, and have illustrated the performance of the method through three lens design examples. PMID:20686583
Zheng, Nan; Hagen, Nathan; Brady, David J
Transition Metal Dichalcogenide Growth via Close Proximity Precursor Supply
NASA Astrophysics Data System (ADS)
Reliable chemical vapour deposition (CVD) of transition metal dichalcogenides (TMDs) is currently a highly pressing research field, as numerous potential applications rely on the production of high quality films on a macroscopic scale. Here, we show the use of liquid phase exfoliated nanosheets and patterned sputter deposited layers as solid precursors for chemical vapour deposition. TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup. A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented. Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, scanning electron microscopy and electrical transport measurements reveal the high quality of the TMD samples produced. Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components.
O'Brien, Maria; McEvoy, Niall; Hallam, Toby; Kim, Hye-Young; Berner, Nina C.; Hanlon, Damien; Lee, Kangho; Coleman, Jonathan N.; Duesberg, Georg S.
Residential proximity to high voltage transmission lines and depressive symptomatology
A number of epidemiological studies indicate an association between depression and proximity to high voltage transmission lines. These studies have been criticized, however, for using surrogate measures of electromagnetic fields (EMFs) and unstandardized measures of depression. In an effort to overcome these limitations, the Center for Epidemiological Studies Depression (CES-D) scale was administered to 152 women living either adjacent to a transmission line or one block away. Results indicate that homes adjacent to the transmission lines have an average EMF level of 4.86 milligauss at their front door and those one block away have an average of 0.68 milligauss. There was no significant difference in CES-D scores between the groups, controlling for demographic variables. There appeared to be an increase in other health effects, including cancer and miscarriages, but these findings were preliminary and need further investigation.
McMahan, S.G.
Proximal Tubule Cell Hypothesis for Cardiorenal Syndrome in Diabetes
Incidence of cardiovascular disease (CVD) is remarkably high among patients with chronic kidney disease (CKD), even in the early microalbuminuric stages with normal glomerular filtration rates. Proximal tubule cells (PTCs) mediate metabolism and urinary excretion of vasculotoxic substances via apical and basolateral receptors and transporters. These cells also retrieve vasculoprotective substances from circulation or synthesize them for release into the circulation. PTCs are also involved in the uptake of sodium and phosphate, which are critical for hemodynamic regulation and maintaining the mineral balance, respectively. Dysregulation of PTC functions in CKD is likely to be associated with the development of CVD and is linked to the progression to end-stage renal disease. In particular, PTC dysfunction occurs early in diabetic nephropathy, a leading cause of CKD. It is therefore important to elucidate the mechanisms of PTC dysfunction to develop therapeutic strategies for treating cardiorenal syndrome in diabetes. PMID:21197105
Saito, Akihiko; Kaseda, Ryohei; Hosojima, Michihiro; Sato, Hiroyoshi
Retroperitoneal Laparoscopic Ureterolithotomy for Proximal Ureteral Calculi in Selected Patients
Objectives. To summarize our experience of retroperitoneal laparoscopic ureterolithotomy for ureteral calculi and evaluate the safety and efficiency of this procedure. Methods. We conducted a retrospective analysis of 197 patients with proximal ureteral calculi who accepted retroperitoneal laparoscopic ureterolithotomy from June 2005 to June 2014. Results. All procedures were performed successfully and the mean operating time and estimated blood loss were 87?min and 64?mL. The clearance rate was 98.5% and the rates of urine leak and ureteral stricture were 2.5% and 1.0%. Conclusions. Retroperitoneal laparoscopic ureterolithotomy is a safe and effective procedure for patients with complex stones or anatomic abnormalities, and, with experience of high volume series, it is also a reasonable choice as the primary treatment for such selected patients. PMID:25548791
Hu, Qingfeng; Ding, Weihong; Gou, Yuancheng; Ho, Yatfaat; Xu, Ke; Gu, Bin; Sun, Chuanyu; Xia, Guowei; Ding, Qiang
Rendezvous, proximity operations and capture quality function deployment report
NASA Astrophysics Data System (ADS)
Rendezvous, Proximity Operations, and Capture (RPOC) is a missions operations area which is extremely important to present and future space initiatives and must be well planned and coordinated. To support this, a study team was formed to identify a specific plan of action using the Quality Function Deployment (QFD) process. This team was composed of members from a wide spectrum of engineering and operations organizations which are involved in the RPOC technology area. The key to this study's success is an understanding of the needs of potential programmatic customers and the technology base available for system implementation. To this end, the study team conducted interviews with a variety of near term and future programmatic customers and technology development sponsors. The QFD activity led to a thorough understanding of the needs of these customers in the RPOC area, as well as the relative importance of these needs.
Lamkin, Stephen L.
Optical proximity correction using a multilayer perceptron neural network
NASA Astrophysics Data System (ADS)
Optical proximity correction (OPC) is one of the resolution enhancement techniques (RETs) in optical lithography, where the mask pattern is modified to improve the output pattern fidelity. Algorithms are needed to generate the modified mask pattern automatically and efficiently. In this paper, a multilayer perceptron (MLP) neural network (NN) is used to synthesize the mask pattern. We employ the pixel-based approach in this work. The MLP takes the pixel values of the desired output wafer pattern as input, and outputs the optimal mask pixel values. The MLP is trained with the backpropagation algorithm, with a training set retrieved from the desired output pattern, and the optimal mask pattern obtained by the model-based method. After training, the MLP is able to generate the optimal mask pattern non-iteratively with good pattern fidelity.
Luo, Rui
Fractures of the tibia through the proximal tibial epiphyseal cartilage.
Thirty-nine fractures of the tibia involving the proximal tibial epiphyseal cartilage were treated at the Campbell Clinic over a twenty-five-year period. Stress roentgenograms were essential in making the diagnosis in three patients. Two patients had disruption of the popliteal artery, and both had posterior displacement of the tibial shaft. The other immediate complications that we encountered were anterior compartment syndrome, peroneal-nerve palsy, and associated ligamentous and meniscal injuries. Of twenty-eight fractures (twenty seven patients) with an average follow-up of 7.1 years, there were satisfactory results in twenty-four. Unsatisfactory results (four fractures) were due to chronic neurovascular insufficiency, growth disturbance, or traumatic arthritis. PMID:581764
Shelton, W R; Canale, S T
Synovial cysts of the proximal tibiofibular joint: three case reports.
Synovial cysts are fluid-filled masses lined with synovium and located within or about joints. The main symptoms are pain and/or neurological deficits. They can be intraneural or extraneural or develop between or within muscles. Synovial cysts that arise at a distance from a joint raise diagnostic challenges. We report three cases of synovial cysts of the proximal tibiofibular joint, including an intramuscular cyst responsible for paralysis of the anterolateral leg muscles. Tibiofibular synovial cysts are less common than popliteal cysts, and their pathophysiology is poorly understood. Pressure on the common peroneal nerve is the main complication and requires careful surgical excision of the cyst. Injection of a glucocorticoid into the cyst can be used as the first-line treatment in patients without common peroneal nerve symptoms. PMID:12102284
Pagnoux, Christian; Lhotellier, Luc; Marek, Joļlle Janse; Ballard, Magali; Chazerain, Pascal; Ziza, Jean-Marc
The physiological response to the onset of metabolic acidosis requires pronounced changes in renal gene expression. Adaptations within the proximal convoluted tubule support the increased extraction of plasma glutamine and the increased synthesis and transport of glucose and of NH4+ and HCO3? ions. Many of these adaptations involve proteins associated with the apical membrane. To quantify the temporal changes in these proteins, proteomic profiling was performed using brush-border membrane vesicles isolated from proximal convoluted tubules (BBMVPCT) that were purified from normal and acidotic rats. This preparation is essentially free of contaminating apical membranes from other renal cortical cells. The analysis identified 298 proteins, 26% of which contained one or more transmembrane domains. Spectral counts were used to assess changes in protein abundance. The onset of acidosis produced a twofold, but transient, increase in the Na+-dependent glucose transporter and a more gradual, but sustained, increase (3-fold) in the Na+-dependent lactate transporter. These changes were associated with the loss of glycolytic and gluconeogenic enzymes that are contained in the BBMVPCT isolated from normal rats. In addition, the levels of ?-glutamyltranspeptidase increased twofold, while transporters that participate in the uptake of neutral amino acids, including glutamine, were decreased. These changes could facilitate the deamidation of glutamine within the tubular lumen. Finally, pronounced increases were also observed in the levels of DAB2 (3-fold) and myosin 9 (7-fold), proteins that may participate in endocytosis of apical membrane proteins. Western blot analysis and accurate mass and time analyses were used to validate the spectral counting. PMID:22357915
Walmsley, Scott J.; Freund, Dana M.
Unexplained proximal tibiofibular joint pain after high tibial osteotomy
Problems of the proximal tibiofibular joint (pTFj) after high tibial osteotomy (HTO) are rare. With this case report, we strive to highlight the importance of investigating the pTFj in patients with unexplained knee pain after HTO. A 44 year old male patient presented with diffuse pain on his left knee 3 years after medial opening wedge HTO due to medial compartment overloading in a varus knee. Patient described persistent anterior tibial and lateral knee pain. 2 years after HTO, patient underwent implant removal but the knee pain persisted. As the reason for the persistent pain was not identified, further radiological evaluation was done. Single photon emission computerized tomography/computerized tomography (SPECT/CT) revealed that there was no increased uptake within the tibiofemoral joint, indicating a biologically well performed correction of the varus deformity. However, markedly increased tracer uptake was found at the pTFj. On the inherent axial CT scans, it was seen that the proximal screws were too long and placed within the pTFj. Along with this a severe osteoarthritis of the pTFj was identified. The cause of the patient's pain was then confirmed by a CT guided infiltration of local anesthetic. An arthrodesis of the pTFj was performed and at 12 months followup after the arthrodesis the patient was pain free. This case highlights how important it is to evaluate the pTFj in patients with unexplained pain after HTO. SPECT/CT was helpful in identifying the patient's problem in this challenging case. PMID:24932045
Testa, Enrique Adrian; Haeni, David L; Behrens, Gerrit; Hirschmann, Michael T
Unexplained proximal tibiofibular joint pain after high tibial osteotomy.
Problems of the proximal tibiofibular joint (pTFj) after high tibial osteotomy (HTO) are rare. With this case report, we strive to highlight the importance of investigating the pTFj in patients with unexplained knee pain after HTO. A 44 year old male patient presented with diffuse pain on his left knee 3 years after medial opening wedge HTO due to medial compartment overloading in a varus knee. Patient described persistent anterior tibial and lateral knee pain. 2 years after HTO, patient underwent implant removal but the knee pain persisted. As the reason for the persistent pain was not identified, further radiological evaluation was done. Single photon emission computerized tomography/computerized tomography (SPECT/CT) revealed that there was no increased uptake within the tibiofemoral joint, indicating a biologically well performed correction of the varus deformity. However, markedly increased tracer uptake was found at the pTFj. On the inherent axial CT scans, it was seen that the proximal screws were too long and placed within the pTFj. Along with this a severe osteoarthritis of the pTFj was identified. The cause of the patient's pain was then confirmed by a CT guided infiltration of local anesthetic. An arthrodesis of the pTFj was performed and at 12 months followup after the arthrodesis the patient was pain free. This case highlights how important it is to evaluate the pTFj in patients with unexplained pain after HTO. SPECT/CT was helpful in identifying the patient's problem in this challenging case. PMID:24932045
Testa, Enrique Adrian; Haeni, David L; Behrens, Gerrit; Hirschmann, Michael T
The NaF documentation files are presented in Adobe Acrobat or Word files. PDF Generic Documentation for NaF PDF file Word Generic Documentation for NaFWord file Contact Paula M. Jacobs, Ph.D., 301-435-9181, email@example.com, for information. Print
Proximal renal tubular acidosis: a not so rare disorder of multiple etiologies
Proximal renal tubular acidosis (RTA) (Type II RTA) is characterized by a defect in the ability to reabsorb HCO3 in the proximal tubule. This is usually manifested as bicarbonate wastage in the urine reflecting that the defect in proximal tubular transport is severe enough that the capacity for bicarbonate reabsorption in the thick ascending limb of Henle's loop and more distal nephron segments is overwhelmed. More subtle defects in proximal bicarbonate transport likely go clinically unrecognized owing to compensatory reabsorption of bicarbonate distally. Inherited proximal RTA is more commonly autosomal recessive and has been associated with mutations in the basolateral sodium-bicarbonate cotransporter (NBCe1). Mutations in this transporter lead to reduced activity and/or trafficking, thus disrupting the normal bicarbonate reabsorption process of the proximal tubules. As an isolated defect for bicarbonate transport, proximal RTA is rare and is more often associated with the Fanconi syndrome characterized by urinary wastage of solutes like phosphate, uric acid, glucose, amino acids, low-molecular-weight proteins as well as bicarbonate. A vast array of rare tubular disorders may cause proximal RTA but most commonly it is induced by drugs. With the exception of carbonic anhydrase inhibitors which cause isolated proximal RTA, drug-induced proximal RTA is associated with Fanconi syndrome. Drugs that have been recently recognized to cause severe proximal RTA with Fanconi syndrome include ifosfamide, valproic acid and various antiretrovirals such as Tenofovir particularly when given to human immunodeficiency virus patients receiving concomitantly protease inhibitors such as ritonavir or reverse transcriptase inhibitors such as didanosine. PMID:23235953
Haque, Syed K.; Ariceta, Gema; Batlle, Daniel
Presynaptic modulation of cholinergic neurotransmission in the human proximal stomach.
1. This study investigates whether the cholinergic neurones, innervating the human proximal stomach, can be modulated by nitric oxide (NO) or vasoactive intestinal polypeptide (VIP), or via presynaptic muscarinic, alpha(2)- or 5-hydroxytryptamine(4) (5-HT(4)-) receptors. 2. Circular muscle strips, without mucosa, were incubated with [(3)H]-choline to incorporate [(3)H]-acetylcholine into the cholinergic transmitter stores. The basal and electrically-induced release of tritium and [(3)H]-acetylcholine were analysed in a medium containing guanethidine (4 x 10(-6) M), hemicholinium-3 (10(-5) M), physostigmine (10(-5) M) and atropine (10(-6) M). Tissues were stimulated twice for 2 min (S(1) and S(2): 40 V, 1 ms, 4 Hz) and drugs were added before S(2). 3. The NO synthase inhibitor L-N(G)-nitroarginine methyl ester (3 x 10(-4) M) and the NO donor sodium nitroprusside (10(-5) M), as well as VIP (10(-7) M) did not influence the basal release nor the electrically-evoked release. 4. The alpha(2)-adrenoceptor agonist UK-14,304 (10(-5) M) significantly inhibited the electrically-evoked release of [(3)H]-acetylcholine, and this was prevented by the alpha(2)-adrenoceptor antagonist rauwolscine (2 x 10(-6) M). 5. The 5-HT(4)-receptor agonist prucalopride (3 x 10(-7) M) significantly enhanced the electrically-evoked release of [(3)H]-acetylcholine, and the 5-HT(4)-receptor antagonist SB204070 (10(-9) M) prevented this. 6. When atropine (10(-6) M) was omitted from the medium and added before the second stimulation, it significantly increased the release of [(3)H]-acetylcholine. 7. These results suggest that the release of acetylcholine from the cholinergic neurones, innervating the circular muscle in the human proximal stomach, can be inhibited via presynaptic muscarinic auto-receptors and alpha(2)-adrenoceptors, and stimulated via presynaptic 5-HT(4)-receptors. No evidence for modulation by NO or VIP was obtained. PMID:11786489
Leclere, Pascal G; Lefebvre, Romain A
Classifying Proximity Soundings with Self-Organizing Maps toward Improving Supercell and Tornado important when forecasting tornadoes. 1. Introduction A wide breadth of work examining supercell thunder not preclude the possibility of supercells or tornadoes. Proximity sound- ings obtained from radiosonde
Straining of the intact and fractured proximal humerus under physiological-like loading
Surgical treatment of proximal humeral fractures remains challenging in elderly patients, primarily due to insufficient implant fixation. Both bone quality and physiological-like loading conditions are commonly overlooked during pre-clinical in vitro evaluation. However, this knowledge is necessary in order to improve surgical treatment of the proximal humerus and the mechanical behavior of implants, particularly in patients with complex fractures and
Zully M. Maldonado; J÷rn Seebeck; Markus O. W. Heller; Doris Brandt; Pierre Hepp; Helmut Lill; Georg N. Duda
Proximal biceps rupture: management of an unusual injury in an arm wrestler.
Arm wrestling may cause unusual injuries, which may require operative repair in the sporting individual. Injury to the proximal biceps as a consequence of arm wrestling has not been reported previously. The diagnosis and treatment of a 36-year-old man who sustained a proximal biceps rupture while arm wrestling and his operative management are described. PMID:17237118
Pratt, D A; Tennent, T D
Background: Proximal migration of a biliary or pancreatic stent is an infrequent event but its management can be technically challenging. Methods: Review of all cases of proximally migrated biliary and pancreatic stents over a 10-year period at a referral pancreatic-biliary center. Data abstracted from patient records included indication for stenting, method of presentation, success of attempt, and method used. Successful
Sandeep Lahoti; Marc F. Catalano; Joseph E. Geenen; Michael J. Schmalz
The formation of a genu recurvatum after partial growth arrest of the proximal tibial physis is uncommon. This contribution deals with the case of a 16 years old male patient who after a direct injury to the proximal tibia four years ago showed a genu recurvatum of 18 degrees. An incomplete upper tibial corticotomy was performed and a hinge type
D. Pennig; D. Baranowski
Endogenous transitional metal and proximate analysis of selected medicinal plants from Pakistan
Transitional metal and proximate analysis plays an important role in assessing the appropriateness of medicinal plants or their extracts orally taken by the marginal communities. To acquaint, various proximate parameters like ash, carbohydrate, protein, fiber, fat and moisture (both dry and wet) and endogenous transition metals like copper, magnesium, manganese, lead, cadmium, iron, chromium and sodium; four medicinal plant species,
Javid Hussain; Riaz Ullah; Najeeb ur Rehman; Abdul Latif Khan; Zia Muhammad; Farman Ullah Khan; Syed Tasleem Hussain; Saeed Anwar
A field experiment examined the tactical peacekeeping behaviors of military-officer teams undergoing training as United Nations military observers. Teams encountered a simulated human-rights violation where two civilians were being abused. Proximity of the female civilian to the team leader was manipulated and significantly influenced teams' commitment to saving the civilians' lives. Proximity increased the frequency of behaviors that were specifically
David R. Mandel; Oshin Vartanian; Barbara D. Adams; Michael H. Thomson
Proximity and Contacts between Older Parents and Their Children: A European Comparison
ERIC Educational Resources Information Center
Using data from the 2004 Survey of Health, Ageing and Retirement in Europe, this article continues and extends recent cross-national research on proximity and contacts of older parents to their children. In addition to a brief description of the geography of families in 10 continental European countries, determinants of intergenerational proximityģ
Hank, Karsten
Autoradiographic Localization of [3H]Gentamicin in the Proximal Renal Tubules of Mice
The site of localization of [3H]gentamicin within mouse kidney is shown to be the proximal renal tubule by coincidence of the radioactivity, as visualized by autoradiography, and the mucopolysaccharide-rich microvilli characteristic of proximal convoluted tubules, as visualized by histochemical staining. Images PMID:426500
Kuhar, Michael J.; Mak, Linda L.; Lietman, Paul S.
ERIC Educational Resources Information Center
In this study, dialectical reflexive practice is used to maintain student-teacher interactions in the zone of proximal development. The zone of proximal development is the development-and-learning unit of the child or learner and the author suggests that it is also the fusion point of Marx's dialectical historical materialism: the creation ofģ
Lisle, Angela
Proximate, mineral and fatty acid composition of fast foods consumed in Bahrain
Purpose ¢ The purpose of this paper is to evaluate the commonly consumed fast foods in Bahrain with respect to proximate, mineral, sterol composition and their fatty acid profile. Design\\/methodology\\/approach ¢ Foods were purchased from the most frequented fast food outlets in Manama city, the capital of Bahrain. Similar types of foods were pooled into one sample. Proximate composition was
Abdulrahman O. Musaiger; Jassim H. Al-Jedah; Reshma Dsouza
Proximity sounding analysis for derechos and supercells: an assessment of similarities
Proximity sounding analysis for derechos and supercells: an assessment of similarities) of derechos (long-lived, widespread damaging convective windstorms) and supercells have been obtained. More than 65 derechos, accompanied by 115 proximity soundings, are identified during the years 1983 to 1993
Doswell III, Charles A.
The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition
The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition Thomas K scyphozoan jellyfish (Cyanea capillata, Rhizostoma octopus and Chrysaora hysoscella). First, bomb). These proximate data were subsequently converted to energy densities. The two techniques (bomb- calorimetry
Hays, Graeme
NASA Astrophysics Data System (ADS)
This manuscript investigates some relations and properties between 2-cyclic self-mappings. In particular, a formal development is given to link some concepts and their basic related properties like those of approximate best proximity points, approximate best proximity point property and cyclic asymptotic regularity.
De la Sen, M.
Characteristics and Clinical Relevance of Proximal Esophageal pH Monitoring
OBJECTIVE:It is well established that various ENT disorders and symptoms may be a manifestation of gastroesophageal reflux disease (GERD). Measuring proximal esophageal acid exposure might be useful in the evaluation of patients with suspected reflux-related ENT manifestations, but the limited available data are conflicting. The aim of the present study was to study the determinants of proximal esophageal acid exposure
Mike Cool; Johan Poelmans; Louw Feenstra; Jan Tack
Effects of operation parameters on multitarget tracking in proximity sensor networks
This paper investigates effects of operation parameters on multitarget tracking in proximity sensor networks. In such a network, the sensors report a detection when a target is within the proximity; otherwise, the sensors report no detection. Previous work has revealed the potential of multitarget tracking via the particle-based probability hypothesis density (PHD) filter when incorporating these binary reports. This work
Qiang Le; Lance M. Kaplan
AirKanoid - Visual Presentation vs. Physical Proximity in Mixed Reality Entertainment Applications
Social interaction is crucial to games. The other players make games interesting, entertaining, and, ultimately, fun. In traditional game settings, physical proximity is an integral part of the social interaction, but with the advent of networked computer games this is changing. The high quality of computer graphics cannot compensate for the missing physical proximity between the players, which is of
Martin Faust; Hartmut Rosch
Knowledge Collaboration and ProximityThe Spatial Organization of Biotech Innovation Projects
This article addresses the role of proximity for knowledge collaboration between dedicated biotechnology firms (DBFs) and related actors. Innovation projects managed by a selection of eight Swedish DBFs are analysed in detail and classified with regard to their specific knowledge characteristics. Based on this classification, explanations to the relative importance of functional and relational proximity to collaborators are sought.The findings
Jerker Moodysson; Ola Jonsson
Human renal proximal and distal (thick ascending limb and early distal convoluted tubule) epithelial cells have been isolated according to their specific antigen expression. The cells were well characterized by flow cytometry, enzyme cytochemistry and electron microscopy and cultured for up to 3 months. Cultured tubular cells coexpressed cytokeratin and vimentin as intermediate filament proteins. While primary isolated cells, proximal
Patrick C. Baer; Ulf W. Tunn; German Nunez; J³rgen E. Scherberich; Helmut Geiger
A study is proposed to test the effects of temporal proximity between the encounter of a stimulus and the receipt of the product on impulsive online buying behavior. In traditional retail settings, temporal proximity between exposure to a stimulus and receipt of the product is an important factor influencing impulsive buying behavior. In most online shopping situations however, there is
Christoph Schneider
of Philosophy in International Development and Regional Planning at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY direct investment (FDI), intra-organizational proximity, and in-house technology development performancesForeign Direct Investment, Intra-organizational Proximity, and Technological Capability: The Case
A disintegrin and metalloprotease 10 (ADAM10) is a zinc protease that mediates ectodomain shedding of numerous receptors including Notch and members of the amyloid precursor protein family (APP, APLP1, and APLP2). Ectodomain shedding frequently activates a process called regulated intramembrane proteolysis (RIP) that links cellular events with gene regulation. To characterize ADAM10 in kidney and in opossum kidney proximal tubule (OKP) cells, we performed indirect immunofluorescence microscopy and immunoblotting of renal membrane fractions using specific antibodies. These studies show that ADAM10 and APLP2 are coexpressed in the proximal tubule and in OKP cells. To study the role of ADAM10 activity in the proximal tubule, we stably overexpressed wild-type ADAM10 or an inactive mutant ADAM10 in OKP cells. We found a direct correlation between the amount of active ADAM10 expressed and 1) the amount of APLP2 ectodomain shed into the culture supernatant and 2) the amount of Na(+)/H(+) exchanger 3 (NHE3) and megalin mRNA and protein expressed compared with control proteins. To establish a link between ADAM10-mediated shedding of APLP2 and the effect on NHE3 and megalin mRNA expression we performed RNA interference experiments using APLP2-specific short hairpin RNA (shRNA) in OKP cells. Cells expressing the APLP2 shRNA showed >80% knock down of APLP2 protein and mRNA as well as 60-70% reduction in NHE3 protein and mRNA. Levels of megalin and Na-K-ATPase protein and mRNA were not changed. These studies show 1) ADAM10 and APLP2 are expressed in proximal tubule cells and, 2) ADAM10 activity has a pronounced effect on expression of specific brush-border proteins. We postulate that ADAM10 and APLP2 may represent elements of a here-to-fore unknown signaling pathway in proximal tubule that link events at the brush border with control of gene expression. PMID:21325636
Cong, Rong; Li, Yuanli; Biemesderfer, Daniel
A Review of Management Options for Proximal Humeral Fractures
Proximal humeral fractures are common and although the majority can be managed non-operatively, the optimal treatment of displaced or complex fractures remains controversial. Non-operative treatment is typically selected for minimally displaced fractures where union rates are high and good or excellent outcomes can be expected in approximately 80% of cases. The aims of surgical fixation are to restore articular surface congruency, alignment and the relationship between the tuberosities and the humeral head. Hemiarthroplasty provides patients with reliable pain relief and its indications include fracture dislocations, humeral head splitting fractures and some three- and four- part fractures. The key areas of surgical technique that influence functional outcome include correctly restoring the humeral height, humeral version and tuberosity position. Function, however, is poor if the tuberosities either fail to unite or mal-unite. The interest in reverse shoulder arthroplasty as an alternative option has therefore recently increased, particularly in older patients with poor bone quality and tuberosity comminution. The evidence supporting this, however, is currently limited to multiple case series with higher level studies currently underway. PMID:25067968
Jordan, Robert W; Modi, Chetan S
Proximity graphs based multi-scale image segmentation
We present a novel multi-scale image segmentation approach based on irregular triangular and polygonal tessellations produced by proximity graphs. Our approach consists of two separate stages: polygonal seeds generation followed by an iterative bottom-up polygon agglomeration into larger chunks. We employ constrained Delaunay triangulation combined with the principles known from the visual perception to extract an initial ,irregular polygonal tessellation of the image. These initial polygons are built upon a triangular mesh composed of irregular sized triangles and their shapes are ad'apted to the image content. We then represent the image as a graph with vertices corresponding to the polygons and edges reflecting polygon relations. The segmentation problem is then formulated as Minimum Spanning Tree extraction. We build a successive fine-to-coarse hierarchy of irregular polygonal grids by an iterative graph contraction constructing Minimum Spanning Tree. The contraction uses local information and merges the polygons bottom-up based on local region-and edge-based characteristics.
Skurikhin, Alexei N [Los Alamos National Laboratory
Electrical capacitance tomography using an accelerated proximal gradient algorithm.
Image reconstruction in electrical capacitance tomography requires a solution of an ill-posed inverse problem. This paper applies an accelerated proximal gradient (APG) singular value thresholding algorithm, which is originally proposed for the matrix completion problem, to image two-phase flow. Aiming to improve the image quality, a nuclear norm-based regularization technique is adopted to treat the ill-posedness of the inverse problem, and a simple updating technique is used to update the sensitivity matrix. Both typical and complicated distributions (e.g., "sun-rise" and cross-shape), have been examined based on a 16-electrode configuration. The results showed that the APG algorithm with updated sensitivity matrix could produce higher quality images when compared to the algorithm based on the typical sensitivity matrix. Both simulation and experiment results indicate that the algorithm developed has been able to achieve good quality reconstructed images with relativity fast computation speed for the cases tested in this paper. PMID:22559536
Xue, Qian; Wang, Huaxiang; Cui, Ziqiang; Yang, Chengyi
TIGAR regulates glycolysis in ischemic kidney proximal tubules.
Tp53-induced glycolysis and apoptosis regulator (TIGAR) activation blocks glycolytic ATP synthesis by inhibiting phosphofructokinase-1 activity. Our data indicate that TIGAR is selectively induced and activated in renal outermedullary proximal straight tubules (PSTs) after ischemia-reperfusion injury in a p53-dependent manner. Under severe ischemic conditions, TIGAR expression persisted through 48 h postinjury and induced loss of renal function and histological damage. Furthermore, TIGAR upregulation inhibited phosphofructokinase-1 activity, glucose 6-phosphate dehydrogenase (G6PD) activity, and induced ATP depletion, oxidative stress, autophagy, and apoptosis. Small interfering RNA-mediated TIGAR inhibition prevented the aforementioned malevolent effects and protected the kidneys from functional and histological damage. After mild ischemia, but not severe ischemia, G6PD activity and NADPH levels were restored, suggesting that TIGAR activation may redirect the glycolytic pathway into gluconeogenesis or the pentose phosphate pathway to produce NADPH. The increased level of NADPH maintained the level of GSH to scavenge ROS, resulting in a lower sensitivity of PST cells to injury. Under severe ischemia, G6PD activity and NADPH levels were reduced during reperfusion; however, blockade of TIGAR enhanced their levels and reduced oxidative stress and apoptosis. Collectively, these results demonstrate that inhibition of TIGAR may protect PST cells from energy depletion and apoptotic cell death in the setting of severe ischemia-reperfusion injury. However, under low ischemic burden, TIGAR activation induces the pentose phosphate pathway and autophagy as a protective mechanism. PMID:25503731
Kim, Jinu; Devalaraja-Narashimha, Kishor; Padanilam, Babu J
Interactive orbital proximity operations planning system instruction and training guide
NASA Technical Reports Server (NTRS)
This guide instructs users in the operation of a Proximity Operations Planning System. This system uses an interactive graphical method for planning fuel-efficient rendezvous trajectories in the multi-spacecraft environment of the space station and allows the operator to compose a multi-burn transfer trajectory between orbit initial chaser and target trajectories. The available task time (window) of the mission is predetermined and the maneuver is subject to various operational constraints, such as departure, arrival, spatial, plume impingement, and en route passage constraints. The maneuvers are described in terms of the relative motion experienced in a space station centered coordinate system. Both in-orbital plane as well as out-of-orbital plane maneuvering is considered. A number of visual optimization aids are used for assisting the operator in reaching fuel-efficient solutions. These optimization aids are based on the Primer Vector theory. The visual feedback of trajectory shapes, operational constraints, and optimization functions, provided by user-transparent and continuously active background computations, allows the operator to make fast, iterative design changes that rapidly converge to fuel-efficient solutions. The planning tool is an example of operator-assisted optimization of nonlinear cost functions.
Grunwald, Arthur J.; Ellis, Stephen R.
Interactive orbital proximity operations planning system instruction and training guide
NASA Astrophysics Data System (ADS)
This guide instructs users in the operation of a Proximity Operations Planning System. This system uses an interactive graphical method for planning fuel-efficient rendezvous trajectories in the multi-spacecraft environment of the space station and allows the operator to compose a multi-burn transfer trajectory between orbit initial chaser and target trajectories. The available task time (window) of the mission is predetermined and the maneuver is subject to various operational constraints, such as departure, arrival, spatial, plume impingement, and en route passage constraints. The maneuvers are described in terms of the relative motion experienced in a space station centered coordinate system. Both in-orbital plane as well as out-of-orbital plane maneuvering is considered. A number of visual optimization aids are used for assisting the operator in reaching fuel-efficient solutions. These optimization aids are based on the Primer Vector theory. The visual feedback of trajectory shapes, operational constraints, and optimization functions, provided by user-transparent and continuously active background computations, allows the operator to make fast, iterative design changes that rapidly converge to fuel-efficient solutions. The planning tool is an example of operator-assisted optimization of nonlinear cost functions.
Grunwald, Arthur J.; Ellis, Stephen R.
Accidents and complications in selective and proximal gastric vagotomy.
In 3 years 266 consecutive patients were electively operated on for ulcer disease with either selective vagotomy (SV) with drainage (159) or proximal gastric vagotomy (PGV) without drainage (107). The total number of operative accidents was 15 (6 percent), similar to that of truncal vagotomy. Perforation of the stomach occurred in six SV and in one PGV. The perforation went unobserved in two patients, of whom one died. Esophageal perforations were not observed. Bleeding from the lesser omentum or from the spleen was seen in seven patients, requiring reoperation in one. Postoperative surgical complications were seen in 25 patients (9 percent): clinical gastric retention was observed in nine patients, five with SV and four with PGV, and 13 had wound abscesses or dehiscence. Fifty-nine patients had other complications, of which 52 were radiologically demonstrated atelectases, mostly without any clinical significance. The total mortality rate was 1.1 percent, similar to that of truncal vagotomy. The duration of the two operative procedures did not differ, and the greater care required for preservation of the nerve of Latarjet tended to diminish the number of operative accidents. PMID:1109513
Kalaja, E; Clemmesen, I; Banke, L; Kragelund, E; Christiansen, P M
Condylar fractures of the proximal and middle phalanges.
We describe the treatment of 74 patients with phalangeal condylar fractures. Twelve patients presenting with undisplaced fractures were initially treated nonoperatively; of these, five displaced, requiring fixation. The remaining seven patients, all children, united uneventfully. Sixty-two patients presenting with displaced fractures were treated with internal fixation using a single lag screw through a lateral approach. The patients were treated semi-electively on a day surgery unit. Twenty-seven patients with unicondylar fractures, all operated on within 2 weeks of injury, regained full range of movement. Thirty-eight patients had loss of extension (range 10-35░) with fixed flexion contractures at the proximal interphalangeal and thumb interphalangeal joints and extensor lag at the distal interphalangeal joints (overall mean extension loss 10░). Although fixation was technically easier during the first week, a delay of 2 weeks before fixation made little difference to the outcome. In our experience, fractures can be taken down and fixed internally even 8 weeks after injury. If nonoperative treatment is initially embarked upon, close monitoring is required with weekly radiographs up to 3 weeks, as these fractures will frequently displace. PMID:24127461
Shewring, D J; Miller, A C; Ghandour, A
Repair of injured proximal tubule does not involve specialized progenitors
Recently we have established that the kidney tubular epithelium is repaired by surviving epithelial cells. It is not known, however, whether a population of intratubular adult progenitor cells are responsible for this epithelial repair after acute kidney injury. In this study, we used an unbiased DNA analog-based approach that does not rely on candidate markers to track multiple rounds of cell division in vivo. In the proximal tubule, robust thymidine analog incorporation was observed postinjury. Cell division was stochastic and enriched among cells that were injured and dedifferentiated. There was no evidence for the presence of a population of specialized progenitors that repeatedly divide in response to injury. Instead, these results indicate that after injury, new epithelial cells arise from self-duplication of surviving cells, most of which are injured. Because the renal papilla contains DNA label-retaining cells and has been proposed as a stem cell niche, we examined the proliferative behavior of these putative progenitors after ischemia-reperfusion injury. Although label-retaining cells in the renal papilla diminished with time after ischemia-reperfusion injury, they neither proliferated nor migrated to the outer medulla or cortex. Thus, nonlethally injured cells repopulate the kidney epithelium after injury in the absence of any specialized progenitor cell population. PMID:21576461
Humphreys, Benjamin D.; Czerniak, Suzanne; DiRocco, Derek P.; Hasnain, Wirasat; Cheema, Rabia; Bonventre, Joseph V.
Achilles allograft reconstruction of a chronic complete proximal hamstring rupture.
Complete rupture of the origin of the hamstrings is an uncommon injury. Primary surgical repair is the treatment of choice, but in some not possible. We present a case of an avid cyclist who had significant disability from a 6-year-old injury. He underwent reconstruction with Achilles allograft and suture anchors. With the knee flexed to 90 degrees and after extensive mobilization, the retracted musculotendinous unit would not reach the ischial tuberosity. Two suture anchors were placed in the ischial tuberosity after soft tissue debridement. One limb of suture from each anchor was placed in the end of an Achilles allograft with a locking suture, with the other end used to pull the end of the graft to the ischial tuberosity. An additional suture was placed in running fashion down each side of the graft. Distally, the graft was fanned out and attached to the retracted hamstrings with interrupted sutures with the knee at 40 degrees and maximal proximal pull on the hamstrings. The patient outcome was excellent. He resumed high level cycling by 6 months after surgery with no symptoms. Isokinetic testing demonstrated a hamstring deficit of 25% at 60 degrees/s, and 20% at 180 degrees/s at 8 months. PMID:19034429
Murray, Patrick J; Lowe, Walter R
Autonomous control procedures for shuttle rendezvous proximity operations
NASA Technical Reports Server (NTRS)
The results are presented of a study which uses fuzzy sets to model a Space Shuttle pilot's reasoning and actions while performing rendezvous proximity operation maneuvers. In this model fuzzy sets are used to simulate smooth and continuous actions as would be expected from an experienced pilot and to simulate common sense reasoning in the decision process. The present model assumes visual information available to the Shuttle pilot from the Shuttle Crew Optical Alignment Sighting (COAS) device and the overhead window and rendezvous radar sensor information available to him from an onboard display. This model will be used in a flight analysis simulator to perform studies requiring a large number of runs, each of which currently needs an engineer in the loop to supply the piloting decisions. This work has much broader implications in control of robots such as the Flight Telerobotic Servicer, in automated pilot control and attitude control, and in advisory and evaluation functions that could be used for flight data monitoring or for testing of various rule sets in flight preparation.
Lea, Robert N.; Mitchell, Eric V.; Goodwin, Mary Ann
A tortuous proximal urethra in urorectal septum malformation sequence?
We observed a newborn boy with urorectal septum malformation sequence. Anomalies of the genitalia and rectum were present. He expired on the first day of life, due to severe lung hypoplasia. Autopsy showed a colon that ended in a blind sac, an enlarged bladder with no grossly visible urethra, and dysplastic kidneys. A cone-shaped tissue at the usual site of the bladder outlet contained tortuous and slit-like lumina, suggesting an undeveloped proximal urethra. The urethral structure was lined by transitional epithelium with squamous metaplasia. Many small buds-lined with columnar epithelium-branched from the urethral structure. These ductal buds lined with columnar epithelium stained for prostatic acid phosphatase. Basal cells surrounding the ductal buds stained for p63 and high molecular weight cytokeratin-supporting an interpretation that the buds were early prostatic ducts with normal histology. To our knowledge, these are the first histological images of an undeveloped, obstructed urethra associated with the urorectal septum malformation sequence. PMID:24665006
Lin, Henry J; Lugo, Hector; Tran, Thu; Tovar, Jason P; Corral, Julia; Zork, Noelia M; Smith, Lynne M; French, Samuel W; Barajas, Luciano
Adaptive image restoration using a proximity measure to boundary
NASA Astrophysics Data System (ADS)
In this study, an iterative maximum a posteriori (MAP) approach using a Bayesian model of Markov random field (MRF) was proposed for image restoration to reduce or remove the noise resulted from imperfect sensing. Image process is assumed to combine the random fields associated with the observed intensity process and the image texture process respectively. The objective measure for determining the optimal restoration of this "double compound stochastic" image process is based on Bayes' theorem, and the MAP estimation employs the Point-Jacobian iteration to obtain the optimal solution. In the proposed algorithm, MRF is used to quantify the spatial interaction probabilistically, that is, to provide a type of prior information on the image texture and the neighbor window of any size is defined for contextual information on a local region. However, the window of a certain size would result in using wrong information for the estimation from adjacent regions with different characteristics at the pixels close to or on the boundary. To overcome this problem, the new method is designed to use less information from more distant neighbors as the pixel is closer to the boundary. It can reduce the possibility to involve the pixel values of adjacent region with different characteristics. The proximity to the boundary is estimated using a non-uniformity measurement based on edge value, standard deviation, entropy, and the 4th moment of intensity distribution. This study evaluated the new scheme using simulation data, and the experimental results show a considerable improvement in image restoration.
Lee, Sang-Hoon
Nebivolol Attenuates Maladaptive Proximal Tubule Remodeling in Transgenic Rats
Background/Aims The impact of nebivolol therapy on the renal proximal tubular cell (PTC) structure and function was investigated in a transgenic (TG) rodent model of hypertension and the cardiometabolic syndrome. The TG Ren2 rat develops nephropathy with proteinuria, increased renal angiotensin II levels and oxidative stress, and PTC remodeling. Nebivolol, a ?1-antagonist, has recently been shown to reduce albuminuria, in part, through reductions in renal oxidative stress. Accordingly, we hypothesized that nebivolol therapy would attenuate PTC damage and tubulointerstitial fibrosis. Methods Young Ren2 (R2-N) and SD (SD-N) rats were treated with nebivolol (10 mg/kg/day) or vehicle (R2-C; SD-C) for 3 weeks. PTC structure and function were tested using transmission electron microscopy and functional measurements. Results Nebivolol treatment decreased urinary N-acetyl-?-D-glucosaminidase, tubulointerstitial ultrastructural remodeling and fibrosis, NADPH oxidase activity, 3-nitrotyrosine levels, and increased megalin and lysosomal-associated membrane protein-2 immunostaining in PTCs. Ultrastructural abnormalities that were improved with therapy included altered canalicular structure, reduced endosomes/lysosomes and PTC vacuoles, basement membrane thickening, and mitochondrial remodeling/fragmentation. Conclusion These observations support the notion that nebivolol may improve PTC reabsorption of albumin and other glomerular filtered small molecular weight proteins in association with the attenuation of oxidative stress, tubulointerstitial injury and fibrosis in this rat model of metabolic kidney disease. PMID:20110666
Hayden, Melvin R.; Habibi, Javad; Whaley-Connell, Adam; Sowers, Dilek; Johnson, Megan; Tilmon, Roger; Jain, Deepika; Ferrario, Carlos; Sowers, James R.
Sex Differences in Proximal Control of the Knee Joint
Following the onset of maturation, female athletes have a significantly higher risk for anterior cruciate ligament (ACL) injury compared with male athletes. While multiple sex differences in lower-extremity neuromuscular control and biomechanics have been identified as potential risk factors for ACL injury in females, the majority of these studies have focused specifically on the knee joint. However, increasing evidence in the literature indicates that lumbopelvic (core) control may have a large effect on knee-joint control and injury risk. This review examines the published evidence on the contributions of the trunk and hip to knee-joint control. Specifically, the sex differences in potential proximal controllers of the knee as risk factors for ACL injury are identified and discussed. Sex differences in trunk and hip biomechanics have been identified in all planes of motion (sagittal, coronal and transverse). Essentially, female athletes show greater lateral trunk displacement, altered trunk and hip flexion angles, greater ranges of trunk motion, and increased hip adduction and internal rotation during sport manoeuvres, compared with their male counterparts. These differences may increase the risk of ACL injury among female athletes. Prevention programmes targeted towards trunk and hip neuromuscular control may decrease the risk for ACL injuries. PMID:21688868
Mendiguchia, Jurdan; Ford, Kevin R.; Quatman, Carmen E.; Alentorn-Geli, Eduard; Hewett, Timothy E.
The renal diseases most frequently associated with myeloma include amyloidosis, monoclonal immunoglobulin deposition disease, and cast nephropathy. Less frequently reported is light chain proximal tubulopathy, a disease characterized by ?-restricted crystal deposits in the proximal tubule cytoplasm. Light chain proximal tubulopathy without crystal deposition is only loosely related to the typical light chain proximal tubulopathy, and little is known about this entity. A search was performed of the 10 081 native kidney biopsy samples processed by our laboratory over the past 2 years for cases that had light chain restriction limited to the proximal tubule cytoplasm. A total of 10 cases of light chain proximal tubulopathy without crystal deposition were found representing 3.1% of light chain-related diseases. Nine of these 10 showed ?-light chain restriction. Only three cases of light chain proximal tubulopathy with crystals were found accounting for 0.9% of light chain-related diseases. Two of these three were ? subtype. Plasma cell dyscrasia was unsuspected in seven of the 10 patients with light chain proximal tubulopathy without crystals at the time of renal biopsy. After the biopsy was reported, follow-up was available on 9/10 patients with 9/9 showing a plasma cell dyscrasia including 8/9 with multiple myeloma. We found that light chain proximal tubulopathy without crystal formation, despite being rarely described in the literature, is over three times more common than light chain proximal tubulopathy with crystal formation in our series. And given that it is often associated with previously unrecognized myeloma, it is a critically important diagnosis. PMID:21701535
Larsen, Christopher P; Bell, Jane M; Harris, Alexis A; Messias, Nidia C; Wang, Yihan H; Walker, Patrick D
Caveolin 1 (CAV-1) functions not only as a constitutive scaffolding protein of caveolae but also as a vesicular transporter and signaling regulator. In the present study, we tested the hypothesis that CAV-1 knockout (CAV-1 KO) inhibits ANG II type 1 [AT1 (AT1a)] receptor-mediated uptake of ANG II in the proximal tubule and attenuates blood pressure responses in ANG II-induced hypertension. To determine the role of CAV-1 in mediating the uptake of FITC-labeled ANG II, wild-type (WT) mouse proximal convoluted tubule cells were transfected with CAV-1 small interfering (si)RNA for 48 h before AT1 receptor-mediated uptake of FITC-labeled ANG II was studied. CAV-1 siRNA knocked down CAV-1 expression by >90% (P < 0.01) and inhibited FITC-labeled ANG II uptake by >50% (P < 0.01). Moreover, CAV-1 siRNA attenuated ANG II-induced activation of MAPK ERK1/2 and Na(+)/H(+) exchanger 3 expression, respectively (P < 0.01). To determine whether CAV-1 regulates ANG II uptake in the proximal tubule, Alexa 488-labeled ANG II was infused into anesthetized WT and CAV-1 KO mice for 60 min (20 ng/min iv). Imaging analysis revealed that Alexa 488-labeled ANG II uptake was decreased by >50% in CAV-1 KO mice (P < 0.01). Furthermore, Val(5)-ANG II was infused into WT and CAV-1 KO mice for 2 wk (1.5 mgĘkg(-1)Ęday(-1) ip). Basal systolic pressure was higher, whereas blood pressure and renal excretory and signaling responses to ANG II were attenuated, in CAV-1 KO mice (P < 0.01). We concluded that CAV-1 plays an important role in AT1 receptor-mediated uptake of ANG II in the proximal tubule and modulates blood pressure and renal responses to ANG II. PMID:25164083
Li, Xiao C; Gu, Victor; Miguel-Qin, Elise; Zhuo, Jia L
Cardiotonic steroids (such as ouabain) signaling through Na/K-ATPase regulate sodium reabsorption in the renal proximal tubule. We report here that reactive oxygen species are required to initiate ouabain-stimulated Na/K-ATPaseĘc-Src signaling. Pretreatment with the antioxidant N-acetyl-l-cysteine prevented ouabain-stimulated Na/K-ATPaseĘc-Src signaling, protein carbonylation, redistribution of Na/K-ATPase and sodium/proton exchanger isoform 3, and inhibition of active transepithelial 22Na+ transport. Disruption of the Na/K-ATPaseĘc-Src signaling complex attenuated ouabain-stimulated protein carbonylation. Ouabain-stimulated protein carbonylation is reversed after removal of ouabain, and this reversibility is largely independent of de novo protein synthesis and degradation by either the lysosome or the proteasome pathways. Furthermore, ouabain stimulated direct carbonylation of two amino acid residues in the actuator domain of the Na/K-ATPase ?1 subunit. Taken together, the data indicate that carbonylation modification of the Na/K-ATPase ?1 subunit is involved in a feed-forward mechanism of regulation of ouabain-mediated renal proximal tubule Na/K-ATPase signal transduction and subsequent sodium transport. PMID:24121502
Yan, Yanling; Shapiro, Anna P.; Haller, Steven; Katragadda, Vinai; Liu, Lijun; Tian, Jiang; Basrur, Venkatesha; Malhotra, Deepak; Xie, Zi-jian; Abraham, Nader G.; Shapiro, Joseph I.; Liu, Jiang
Background Stable trochanteric femur fractures can be treated successfully with conventional implants such as sliding hip screw, cephalomedullary nails, angular blade plates. However comminuted and unstable inter or subtrochanteric fractures with or without osteoporosis are challenging & prone to complications. The PF-LCP is a new implant that allows angular stability by creating fixed angle block for treatment of complex, comminuted proximal femoral fractures. Method We reviewed 30 patients with unstable interĀor subtrochanteric fractures, which were stabilized with PF-LCP. Mean age of patient was 65 years, and average operative time was 80Āmin. Patients were followed up for a period of 3 years (June 2010¢June 2013). Patients were examined regularly at 3 weekly interval for signs of union (radiological & clinical), varus collapse (neck-shaft angle), limb shortening, and hardware failure. Result All patients showed signs of union at an average of 9 weeks (8¢10 weeks), with minimum varus collapse (<10░), & no limb shortening and hardware failure. Results were analysed using IOWA (Larson) hip scoring. Average IOWA hip score was 77.5. Conclusion PF-LCP represents a feasible alternative for treatment of unstable inter- or subtrochanteric fractures.
Kumar, Nishikant; Kataria, Himanshu; Yadav, Chandrashekhar; Gadagoli, Bharath S.; Raj, Rishi
Proximity to crops and residential to agricultural herbicides in Iowa
Rural residents can be exposed to agricultural pesticides through the proximity of their homes to crop fields. Previously, we developed a method to create historical crop maps using a geographic information system. The aim of the present study was to determine whether crop maps are useful for predicting levels of crop herbicides in carpet dust samples from residences. From homes of participants in a case-control study of non-Hodgkin lymphoma in Iowa (1998-2000), we collected vacuum cleaner dust and measured 14 herbicides with high use on corn and soybeans in Iowa. Of 112 homes, 58% of residences had crops within 500 m of their home, an intermediate distance for primary drift from aerial and ground applications. Detection rates for herbicides ranged from 0% for metribuzin and cyanazine to 95% for 2,4-dichlorophenoxyacetic acid. Six herbicides used almost exclusively in agriculture were detected in 28% of homes. Detections and concentrations were highest in homes with an active farmer. Increasing acreage of corn and soybean fields within 750 m of homes was associated with significantly elevated odds of detecting agricultural herbicides compared with homes with no crops within 750 m (adjusted odds ratio per 10 acres = 1.06; 95% confidence interval, 1.02-1.11). Herbicide concentrations also increased significantly with increasing acreage within 750 m. We evaluated the distance of crop fields from the home at < 100, 101-250, 251-500, and 501-750 m. Including the crop buffer distance parameters in the model did not significantly improve the fit compared with a model with total acres within 750 m. Our results indicate that crop maps may be a useful method for estimating levels of herbicides in homes from nearby crop fields.
Ward, M.H.; Lubin, J.; Giglierano, J.; Colt, J.S.; Wolter, C.; Bekiroglu, N.; Camann, D.; Hartge, P.; Nuckols, J.R.
Aging, health expenditure, proximity to death, and income in Finland.
This study revisits the debate on the 'red herring', i.e. the claim that population aging will not have a significant impact on health care expenditure (HCE), using a Finnish data set. We decompose HCE into several components and include both survivors and deceased individuals into the analyses. We also compare the predictions of health expenditure based on a model that takes into account the proximity to death with the predictions of a na've model, which includes only age and gender and their interactions. We extend our analysis to include income as an explanatory variable. According to our results, total expenditure on health care and care of elderly people increases with age but the relationship is not as clear as is usually assumed when a na've model is used in health expenditure projections. Among individuals not in long-term care, we found a clear positive relationship between expenditure and age only for health centre and psychiatric inpatient care. In somatic care and prescribed drugs, the expenditure clearly decreased with age among deceased individuals. Our results emphasize that even in the future, health care expenditure might be driven more by changes in the propensity to move into long-term care and medical technology than age and gender alone, as often claimed in public discussion. We do not find any strong positive associations between income and expenditure for most non-LTC categories of health care utilization. Income was positively related to expenditure on prescribed medicines, in which cost-sharing between the state and the individual is relatively high. Overall, our results indicate that the future expenditure is more likely to be determined by health policy actions than inevitable trends in the demographic composition of the population. PMID:18634626
Hõkkinen, Unto; Martikainen, Pekka; Noro, Anja; Nihtilõ, Elina; Peltola, Mikko
Renal Fanconi syndrome: taking a proximal look at the nephron.
Renal Fanconi syndrome (RFS) refers to the generalized dysfunction of the proximal tubule (PT) (Kleta R. Fanconi or not Fanconi? Lowe syndrome revisited. Clin J Am Soc Nephrol 2008; 3: 1244-1245). In its isolated form, RFS only affects the PT, but not the other nephron segments. The study of isolated RFS can thus provide specific insights into the function of the PT. In a recent paper, Klootwijk et al. investigated one such form of isolated RFS and revealed the underlying molecular basis (Klootwijk ED, Reichold M, Helip-Wooley A et al. Mistargeting of peroxisomal EHHADH and inherited renal Fanconi's syndrome. N Engl J Med 2014; 370: 129-138). The affected family had been described previously, demonstrating the typical features of RFS, such as low-molecular weight proteinuria, aminoaciduria, glycosuria and phosphaturia with consequent rickets; yet, importantly, patients had no evidence of impaired glomerular filtration (Tolaymat A, Sakarcan A, Neiberger R. Idiopathic Fanconi syndrome in a family. Part I. Clinical aspects. J Am Soc Nephrol 1992; 2: 1310-1317). Inheritance was consistent with an autosomal dominant mode. Klootwijk et al. discovered a surprising explanation: a heterozygous missense mutation causing partial mistargeting of the peroxisomal enzyme EHHADH to the mitochondria. Notably, disease causing was not the absence of the enzyme in the peroxisome, but its interference with mitochondrial function. The discovery of this novel disease mechanism not only confirmed the importance of mitochondrial function for PT transport, but also demonstrated the critical dependence of PT on fatty acid metabolism for energy generation. PMID:25492894
Klootwijk, Enriko D; Reichold, Markus; Unwin, Robert J; Kleta, Robert; Warth, Richard; Bockenhauer, Detlef
Distal radius hemiarthroplasty combined with proximal row carpectomy: case report.
Severe wrist arthritis is most commonly treated by complete wrist arthrodesis, which provides predictable pain relief but the loss of motion may reduce ease of function. In selected patients, motion preserving surgical options, including limited intercarpal fusion, proximal row carpectomy (PRC), and total wrist arthroplasty (TWA) are considered. However, limited fusion and PRC are typically possible only in less severe cases in which there are some articular surfaces showing minimal degeneration that can be retained. TWA is an option for patients who have lower activity demands and specific needs or desires to maintain some wrist motion. Recent utility and decision analysis studies demonstrate that arthroplasty is associated with higher qualify adjusted life year (QALY) than arthrodesis in patients with rheumatoid arthritis. Despite these positive aspects of TWA, the procedure is not as widely accepted as hip, knee, or shoulder arthroplasty. Early implants had problems related to both materials and design, with breakage, loosening and joint imbalance being common complications. Newer generation implants are improved with more predictable early function, less joint imbalance, and rare breakage, but distal component loosening remains a substantial problem. Thus, patients with poor bone stock and those with high activity demands are typically not candidates for TWA, and all patients are advised to restrict activities to reduce the risk of implant loosening. A new motion preserving procedure has recently been used at our institution in selected patients with severe arthritis who do not qualify for TWA but request an alternative to complete wrist fusion. In this procedure, a distal radius implant arthroplasty is combined with a PRC. The distal radius component of a Universal 2 (UNI 2) total wrist arthroplasty system (Integra life Sciences, Plainsboro, NJ) is used. To our knowledge, there have been no previous publications on this technique. We report our first two cases which have shown a satisfactory early outcome for pain relief and functional wrist motion. PMID:21045991
Boyer, Jeffrey S; Adams, Brian
Retrograde cartilage transplantation on the proximal and distal tibia.
The authors, with experience with more than 400 osteochondral autograft transplantation (OATS) cases since 1996, report a new technique of a retrograde osteochondral autograft transplantation for the treatment of isolated osteochondral lesions of the proximal and the distal tibia started in 1999. We treated 5 patients, 3 who presented with painful traumatic chondral defects in the central weight-bearing portion of the tibial plateau (1 in the medial and 2 in the lateral compartment), and 2 who presented with painful chondral lesions on the distal tibia. An anterior cruciate ligament (ACL) drill guide positioned in the center of the defect was used to accurately prepare the cartilage surface, in one case arthroscopically and in 4 cases through an open incision. A guide-wire was introduced and drilled through the tibia, and a cannulated reamer equal to the diameter of the defect was advanced. An osteochondral cylinder was harvested from the non-weight-bearing zone of the femoral trochlea at the angle that corresponded to the angle on the ACL drill guide. The autograft was inserted in a retrograde fashion from the cortical window into the tibial tunnel to be flush with the articular surface in press-fit technique. The remaining tunnel defect between the cortical window on the tibia and the distal aspect of the autograft was filled with a cancellous bony cylinder and secured with a diagonal bioabsorbable screw. A concomitant varus deformity with the lesion on the medial tibial plateau was corrected in the same surgery using a high tibial osteotomy to relieve stress on the graft. Patients were followed up for 6 to 35 months. A complete healing of the grafts was seen in control magnetic resonance images (MRIs). All patients were satisfied with the surgery. Control arthroscopies showed the osteochondral cylinders well integrated and flush with the articular surface. PMID:14716283
Ueblacker, Peter; Burkart, Andreas; Imhoff, Andreas Balthasar
Factors influencing the speed of sound through the proximal phalanges.
The amplitude-dependent speed of sound (AD-SOS) in the proximal phalanges is reported to be sensitive to osteoporotic changes. We investigated the influence of bone thickness and cortical thickness on AD-SOS. Phantoms made of Perspex were designed to simulate different bone width (11-16 mm) and cortical thickness (3-7.5 mm). The phantoms were designed with two opposing flat and cylindrical surfaces. The effect of cortical thickness was examined by drilling holes (simulating the medullary canal) of different diameters (1-7 mm) in the middle of the Perspex cylinders. The effect of sample thickness was investigated on solid Perspex phantoms of varied lengths. The standardized precision errors of AD-SOS measurement in vivo and in vitro on volunteers and phantoms were 2.8 and 0.9%, respectively. AD-SOS was influenced by the bone width, cortical thickness, and location along the phalanx. A decrease in either cortical width or cortical thickness resulted in a decrease in AD-SOS. The effect is dependent on whether the contact surface is curved or flat. It is possible that a curved surface has a focusing effect on the wave through the porous core, whereas for a flat surface, the path of the waves might not pass through the center. When cortical thickness and bone width were expressed as a ratio, there was a linear relationship between this ratio and AD-SOS through the phantoms. AD-SOS was independent of thickness for samples greater than 11 mm. PMID:10548820
Njeh, C F; Richards, A; Boivin, C M; Hans, D; Fuerst, T; Genant, H V
Proximity Effect in Nb/Mg/CoFe Trilayers.
NASA Astrophysics Data System (ADS)
We have fabricated the Nb/Mg bilayer and Nb/Mg/CoFe trilayer samples by varying Mg layer thickness and measured their superconducting transition temperature Tc electrically using the 4-prove method. Mg normal layer was used to investigate the effect of its small atomic number, since we have observed previously the largely different behavior when Au, Cu and Al were used. When the Al layer was used, a very unusual behavior was found. Because of chemical interaction between Nb and Mg, the Tc transition curves did not show sharp Tc transition. In order to prevent this interaction, we inserted 2 nm thick Al layer between Nb and Mg. In the case of Nb/Al(2nm)/Mg, we observed Tc behavior consistent with a conventional SN theory. In the case of Nb/Al(2nm)/Mg/CoFe with fixed thicknesses of Nb and CoFe layer, the Tc values exhibited two distinct behavior as the thickness of Mg increased. The Tc value of S/N/F trialyer increased rapidly until the Mg thickness reached a few nm. As Mg thickness increased further to 200 nm, the Tc value of S/N/F decreased again, following closely those of the S/N data. Overall, the Mg data basically followed those of Al data, suggesting that the low atomic number of the normal layer is important in observing the unusual proximity effect in SNF trilayers. Our analysis of the interface effect using an Usadel picture will be presented.
Choi, Seong Kook; Kwon, Jun Hyung; Char, Kookrin
Background Proximal humeral fractures are common osteoporotic fractures. Most proximal humeral fractures are treated non-surgically, although surgical treatment has gained popularity. The purpose of this study was to determine changes in the surgical treatment of proximal humeral fractures in Finland between 1987 and 2009. Methods The study covered the entire adult (>19 y) population in Finland over the 23-year period from 1st of January 1987 to 31st of December 2009. We assessed the number and incidence of surgically treated proximal humeral fractures in each year of observation and recorded the type of surgery used. The cohort study was based on data from Finnish National Hospital Discharge Register. Results During the 23-year study period, a total of 10,560 surgical operations for proximal humeral fractures were performed in Finland. The overall incidence of these operations nearly quadrupled between 1987 and 2009. After the year 2002, the number of patients treated with plating increased. Conclusion An increase in the incidence of the surgical treatment of proximal humeral fractures was seen in Finland in 1987¢2009. Fracture plating became increasingly popular since 2002. As optimal indications for each surgical treatment modality in the treatment of proximal humeral fractures are not known, critical evaluation of each individual treatment method is needed. PMID:23273247
Self-perceptions of proximal stability as measured by the functional movement screen.
This mixed method study was designed to investigate self-perceptions before and after experiencing an activity that dynamically and statically challenges proximal stability of the pelvis, spine, and trunk. Twenty-eight, healthy Division II female soccer and volleyball collegiate players (17 soccer, 11 volleyball) completed a self-reported Tegner activity scale, pretest questionnaire and posttest interview. A self-perceived numeric rating of the athletes' proximal stability and performance on a functional movement screen (FMS) were recorded. A guided interview was used to examine the self-perceptions of proximal stability after the FMS testing session. Differences and correlations between the pretest and posttest ratings of proximal stability and FMS scores were analyzed using a 1-sample Kolmogorov-Smirnov test and Spearman's rank order correlation test, respectively. Residual standard error from a 1-way analysis of variance was used to explore the association between variables. Qualitative data were recorded and transcribed. There were significant differences between the pretest (3.4 ▒ 0.63) and posttest ratings (3.1 ▒ 0.49) of proximal stability (p = 0.01). The relationship between the pretest proximal stability ratings and the FMS scores was low (r = 0.19, p = 0.33), whereas posttest rating and FMS scores had a moderately high (r = 0.68, p = 0.00) correlation. There was a smaller residual standard error for the posttest ratings (1.7) when compared with the pretest ratings (3.2) with the FMS. Four qualitative themes emerged: (a) wanting to do well, (b) expectations of performance, (c) focused mental mindset, and (d) body control. Self-perceptions of proximal stability in female athletes were influenced by undergoing a test that stressed the proximal stabilizers. Combining assessments of self-perceptions and proximal stability may assist clinicians and athletes in targeting components of training. PMID:23207886
Palmer, Thomas G; Howell, Dana M; Mattacola, Carl G; Viele, Kert
During surgery for an abdominal aortic aneurysm, various problems can occur at the proximal anastomosis. Adequate exposure must be secured, and the proximal anastomosis must be sutured firmly. We have used a malleable U-shaped retractor to easily secure exposure of the proximal anastomosis. Despite recent advances in endovascular treatment, abdominal aortic aneurysm repair often requires open surgery. We describe our malleable U-shaped retractor technique, which is very easy and facilitates the creation of a secure proximal anastomosis.
Cho, Tomoki; Yasuda, Shota; Izubuchi, Ryo; Masuda, Munetaka
NBCe1-A electrogenically cotransports Na(+) and HCO(3)(-) across the basolateral membrane of renal proximal tubule cells. Eight missense mutations and 3 nonsense mutations in NBCe1-A cause severe proximal renal tubular acidosis (pRTA). In this study, the topologic properties and structural importance of the 8 endogenous residues mutated in pRTA and the in situ topology of NBCe1-A were examined by the substituted cysteine accessibility method. Of the 55 analyzed individually introduced cysteines, 8 were labeled with both membrane permeant (biotin maleimide (BM)) and impermeant (2-((5(6)-tetramethylrhodamine)carboxylamino)ethyl methanethiosulfonate (MTS-TAMRA)) sulfhydryl reagents, 4 with only BM, and 3 with only MTS-TAMRA. The location of the labeled and unlabeled introduced cysteines clearly indicates that the transmembrane region of NBCe1-A contains 14 transmembrane segments (TMs). In this in situ based NBCe1-A topology, residues mutated in pRTA (pRTA residues) are assigned as: Ser(427), TM1; Thr(485) and Gly(486), TM3; Arg(510) and Leu(522), TM4; Ala(799), TM10; and Arg(881), TM12. Substitution of pRTA residues with cysteines impaired the membrane trafficking of R510C and R881C, the remaining membrane-processed constructs had various impaired transport function. Surprisingly, none of the membrane-processed constructs was accessible to labeling with BM and MTS-TAMRA, nor were they functionally sensitive to the inhibition by (2-aminoethyl)methanethiosulfonate. Functional analysis of Thr(485) with different amino acid substitutions indicated it resides in a unique region important for NBCe1-A function. Our findings demonstrate that the pRTA residues in NBCe1-A are buried in the protein complex/lipid bilayer where they perform important structural roles. PMID:20197274
Zhu, Quansheng; Kao, Liyo; Azimov, Rustam; Newman, Debra; Liu, Weixin; Pushkin, Alexander; Abuladze, Natalia; Kurtz, Ira
Calculation of cluster decays half-lives for nuclei between 56 temperature dependent proximity model
Cluster decays half-lives of elements with proton numbers between 56 temperature dependent proximity potential approach. for showing the influence of temperature on cluster decays, we compared the results among temperature dependent and inde-pendent case with experimental values. The obtained results of the present investigation reveal that we have more accurate results for temperature dependent proximity potential in comparison to ignoring one. In the present work, we find that results provided with temperature dependent prox-imity model are reasonable estimates for cluster decays half-lives and provide reliable predictions for other super heavies cluster decays.
Vahid Zanganeh
A 75-year-old woman who had undergone hybrid metal-on-metal hip resurfacing 8?years earlier underwent revision arthroplasty because of hip, groin and lateral thigh pain. The main differential was aseptic loosening; however, serum cobalt and chromium levels were normal. Multiple imaging modalities revealed a periprosthetic, cystic soft tissue mass adjacent to the proximal femur. A large 'pseudotumour' with proximal femoral invasion was found at revision arthroplasty. We report the first finding of a 'pseudotumour' invading the proximal femur with normal metal ions following metal on metal hip resurfacing. PMID:25670783
Krishnan, Harry; Sugand, Kapil; Ali, Ibrahim; Smith, Jay
A retrospective analysis was done of 52 rotational tibial osteotomies (RTOs) performed on 35 patients with severe idiopathic tibial torsion. Thirty-nine osteotomies were performed at the proximal or midtibial level. Thirteen were performed at the distal tibial level with a technique previously described by one of the authors. Serious complications occurred in five (13%) of the proximal and in none of the distal RTOs. For severe and persisting idiopathic tibial torsion, the authors recommend correction by RTO at the distal level. Proximal level osteotomy is indicated only when a varus or valgus deformity required concurrent correction. PMID:1395261
Krengel, W F; Staheli, L T
The signatures of the onset of deconfinement, found by the NA49 experiment at low SPS energies, are confronted with new results from the Beam Energy Scan (BES) program at BNL RHIC and CERN LHC results. Additionally, new NA49 results on chemical (particle ratio) fluctuations, azimuthal angle fluctuations, intermittency of di-pions, etc. are presented.
Katarzyna Grebieszkow; for the NA49 Collaboration
Spatial mismatch between the Na+ flux and spike initiation in axon initial segment
It is widely believed that, in cortical pyramidal cells, action potentials (APs) initiate in the distal portion of axon initial segment (AIS) because that is where Na+ channel density is highest. To investigate the relationship between the density of Na+ channels and the spatiotemporal pattern of AP initiation, we simultaneously recorded Na+ flux and action currents along the proximal axonal length. We found that functional Na+ channel density is approximately four times lower in the AP trigger zone than in the middle of the AIS, where it is highest. Computational analysis of AP initiation revealed a paradoxical mismatch between the AP threshold and Na+ channel density, which could be explained by the lopsided capacitive load imposed on the proximal end of the AIS by the somatodendritic compartment. Favorable conditions for AP initiation are therefore achieved in the distal AIS portion, close to the edge of myelin, where the current source¢load ratio is highest. Our findings suggest that cable properties play a central role in determining where the AP starts, such that small plastic changes in the local AIS Na+ channel density could have a large influence on neuronal excitability as a whole. PMID:23341597
Baranauskas, Gytis; David, Yaron; Fleidervish, Ilya A.
In the recent submicron technologies, the pattern formation on photomasks is increasing in its difficulty owing to the complexity of optical proximity effect correction (OPC) and resolution enhancement techniques (RET). The detection and repair of critical patterns after OPC or RET have become essential procedures for photomask preparation, and design rule check (DRC) or lithography simulation tools have often been
Katsuhiko Harazaki; Tasuku Yoshioka; Kiyoshige Ohmori; Masayuki Satoh; Akio Kawamura
Identification of functionally distinct Na-HCO3 co-transporters in colon.
Na-HCO3 cotransport (NBC) regulates intracellular pH (pHi) and HCO3 secretion in rat colon. NBC has been characterized as a 5,5'-diisothiocyanato-2-2'-stilbene (DIDS)-sensitive transporter in several tissues, while the colonic NBC is sensitive to both amiloride and DIDS. In addition, the colonic NBC has been identified as critical for pHi regulation as it is activated by intravesicular acid pH. Molecular studies have identified several characteristically distinct NBC isoforms [i.e. electrogenic (NBCe) and electroneutral (NBCn)] that exhibit tissue specific expression. This study was initiated to establish the molecular identity and specific function of NBC isoforms in rat colon. Northern blot and reverse transcriptase PCR (RT-PCR) analyses revealed that electrogenic NBCe1B or NBCe1C (NBCe1B/C) isoform is predominantly expressed in proximal colon, while electroneutral NBCn1C or NBCn1D (NBCn1C/D) is expressed in both proximal and distal colon. Functional analyses revealed that amiloride-insensitive, electrogenic, pH gradient-dependent NBC activity is present only in basolateral membranes of proximal colon. In contrast, amiloride-sensitive, electroneutral, [H(+)]-dependent NBC activity is present in both proximal and distal colon. Both electrogenic and electroneutral NBC activities are saturable processes with an apparent Km for Na of 7.3 and 4.3 mM, respectively; and are DIDS-sensitive with apparent Ki of 8.9 and 263.8 ĄM, respectively. In addition to Na-H exchanger isoform-1 (NHE1), pHi acidification is regulated by a HCO3-dependent mechanism that is HOE694-insensitive in colonic crypt glands. We conclude from these data that electroneutral, amiloride-sensitive NBC is encoded by NBCn1C/D and is present in both proximal and distal colon, while NBCe1B/C encodes electrogenic, amiloride-insensitive Na-HCO3 cotransport in proximal colon. We also conclude that NBCn1C/D regulates HCO3-dependent HOE694-insensitive Na-HCO3 cotransport and plays a critical role in pHi regulation in colonic epithelial cells. PMID:23690961
Barmeyer, Christian; Ye, Jeff Huaqing; Soroka, Carol; Geibel, Peter; Hingsammer, Lukas M; Weitgasser, Laurence; Atway, Danny; Geibel, John P; Binder, Henry J; Rajendran, Vazhaikkurichi M
Identification of Functionally Distinct Na-HCO3 Co-Transporters in Colon
Na-HCO3 cotransport (NBC) regulates intracellular pH (pHi) and HCO3 secretion in rat colon. NBC has been characterized as a 5,5?-diisothiocyanato-2-2?-stilbene (DIDS)-sensitive transporter in several tissues, while the colonic NBC is sensitive to both amiloride and DIDS. In addition, the colonic NBC has been identified as critical for pHi regulation as it is activated by intravesicular acid pH. Molecular studies have identified several characteristically distinct NBC isoforms [i.e. electrogenic (NBCe) and electroneutral (NBCn)] that exhibit tissue specific expression. This study was initiated to establish the molecular identity and specific function of NBC isoforms in rat colon. Northern blot and reverse transcriptase PCR (RT-PCR) analyses revealed that electrogenic NBCe1B or NBCe1C (NBCe1B/C) isoform is predominantly expressed in proximal colon, while electroneutral NBCn1C or NBCn1D (NBCn1C/D) is expressed in both proximal and distal colon. Functional analyses revealed that amiloride-insensitive, electrogenic, pH gradient-dependent NBC activity is present only in basolateral membranes of proximal colon. In contrast, amiloride-sensitive, electroneutral, [H+]-dependent NBC activity is present in both proximal and distal colon. Both electrogenic and electroneutral NBC activities are saturable processes with an apparent Km for Na of 7.3 and 4.3 mM, respectively; and are DIDS-sensitive with apparent Ki of 8.9 and 263.8 ĄM, respectively. In addition to Na-H exchanger isoform-1 (NHE1), pHi acidification is regulated by a HCO3-dependent mechanism that is HOE694-insensitive in colonic crypt glands. We conclude from these data that electroneutral, amiloride-sensitive NBC is encoded by NBCn1C/D and is present in both proximal and distal colon, while NBCe1B/C encodes electrogenic, amiloride-insensitive Na-HCO3 cotransport in proximal colon. We also conclude that NBCn1C/D regulates HCO3-dependent HOE694-insensitive Na-HCO3 cotransport and plays a critical role in pHi regulation in colonic epithelial cells. PMID:23690961
Barmeyer, Christian; Ye, Jeff Huaqing; Soroka, Carol; Geibel, Peter; Hingsammer, Lukas M.; Weitgasser, Laurence; Atway, Danny; Geibel, John P.; Binder, Henry J.; Rajendran, Vazhaikkurichi M.
Interindividual variability in social insects - proximate causes and ultimate consequences.
Individuals within social groups often show consistent differences in behaviour across time and context. Such interindividual differences and the evolutionary challenge they present have recently generated considerable interest. Social insects provide some of the most familiar and spectacular examples of social groups with large interindividual differences. Investigating these within-group differences has a long research tradition, and behavioural variability among the workers of a colony is increasingly regarded as fundamental for a key feature of social insects: division of labour. The goal of this review is to illustrate what we know about both the proximate mechanisms underlying behavioural variability among the workers of a colony and its ultimate consequences; and to highlight the many open questions in this research field. We begin by reviewing the literature on mechanisms that potentially introduce, maintain, and adjust the behavioural differentiation among workers. We highlight the fact that so far, most studies have focused on behavioural variability based on genetic variability, provided by e.g. multiple mating of the queen, while other mechanisms that may be responsible for the behavioural differentiation among workers have been largely neglected. These include maturational, nutritional and environmental influences. We further discuss how feedback provided by the social environment and learning and experience of adult workers provides potent and little-explored sources of differentiation. In a second part, we address what is known about the potential benefits and costs of increased behavioural variability within the workers of a colony. We argue that all studies documenting a benefit of variability so far have done so by manipulating genetic variability, and that a direct test of the effect of behavioural variability on colony productivity has yet to be provided. We emphasize that the costs associated with interindividual variability have been largely overlooked, and that a better knowledge of the cost/benefit balance of behavioural variability is crucial for our understanding of the evolution of the mechanisms underlying the social organization of insect societies. We conclude by highlighting what we believe to be promising but little-explored avenues for future research on how within-colony variability has evolved and is maintained. We emphasize the need for comparative studies and point out that, so far, most studies on interindividual variability have focused on variability in individual response thresholds, while the significance of variability in other parameters of individual response, such as probability and intensity of the response, has been largely overlooked. We propose that these parameters have important consequences for the colony response. Much more research is needed to understand if and how interindividual variability is modulated in order to benefit division of labour, homeostasis and ultimately colony fitness in social insects. PMID:24341677
Jeanson, Raphaļl; Weidenm³ller, Anja
Extraction of Hydrological Proximity Measures from DEMs using Parallel Processing
Land surface topography is one of the most important terrain properties which impact hydrological, geomorphological, and ecological processes active on a landscape. In our previous efforts to develop a soil depth model based upon topographic and land cover variables, we extracted a set of hydrological proximity measures (HPMs) from a Digital Elevation Model (DEM) as potential explanatory variables for soil depth. These HPMs may also have other, more general modeling applicability in hydrology, geomorphology and ecology, and so are described here from a general perspective. The HPMs we derived are variations of the distance up to ridge points (cells with no incoming flow) and variations of the distance down to stream points (cells with a contributing area greater than a threshold), following the flow path. These HPMs were computed using the D-infinity flow model that apportions flow between adjacent neighbors based on the direction of steepest downward slope on the eight triangular facets constructed in a 3 x 3 grid cell window using the center cell and each pair of adjacent neighboring grid cells in turn. The D-infinity model typically results in multiple flow paths between 2 points on the topography, with the result that distances may be computed as the minimum, maximum or average of the individual flow paths. In addition, each of the HPMs, are calculated vertically, horizontally, and along the land surface. Previously, these HPMs were calculated using recursive serial algorithms which suffered from stack overflow problems when used to process large datasets, limiting the size of DEMs that could be analyzed using that method to approximately 7000 x 7000 cells. To overcome this limitation, we developed a message passing interface (MPI) parallel approach for calculating these HPMs. The parallel algorithms of the HPMs spatially partition the input grid into stripes which are each assigned to separate processes for computation. Each of those processes then uses a queue data structure to order the processing of cells so that each cell is visited only once and the cross-process communications that are a standard part of MPI are handled in an efficient manner. This parallel approach allows analysis of much larger DEMs as compared to the serial recursive algorithms. In this paper, we present the definitions of the HPMs, the serial and parallel algorithms used in their extraction and their potential applications in hydrology, geomorphology and ecology.
Tesfa, Teklu K.; Tarboton, David G.; Watson, Daniel W.; Schreuders, Kimberly A.; Baker, Matthew M.; Wallace, Robert M.
Proximity soundings of thundersnow in the central United States
NASA Astrophysics Data System (ADS)
Proximity balloon soundings for snow events with lightning and thunder during the period 1961 through 1990 reveal a less statically stable environment than similar nonthundering snow events. When thundersnow is present, a less stable environment (and in some cases subsequent upright convection) is found aloft in all of the thundering cases examined here; all of the events feature their most unstable parcel originating above a frontal inversion. In fact, only events in the cold air north of an extratropical cyclone are included in this study. Events with a lake effect or orographic enhancement are eliminated from the sample. The basic composite derived by averaging temperatures at an established interval reveals a nearly saturated lower atmosphere, below 0░C throughout its depth, with the frontal inversion present and its most unstable parcel occurring just above the top of the inversion. The feature-preserving composite approach of R. A. Brown (1993) better defines the frontal inversion bottom and top as well as the level and temperature of the most unstable parcel; these are the features in need of preservation, and a less statically stable environment emerges by doing so. Other salient features include the most unstable parcel originating some 30-50 mbar above the top of the frontal inversion and significant drying ś100 mbar above the level of the most unstable parcel. The bulk sounding characteristics also favor the existence of lightning. The composite temperature at the level of the most unstable parcel is -8.7░C, which allows for enhanced amounts of supercooled water to enter any updraft that may form. The temperature of the most unstable parcel at its origin is also warmer than the charge reversal temperature; therefore convection of any appreciable depth will span that level. Moreover, the height of the composited -10░C level is 2959 m above ground level, which previous investigators have shown is sufficiently high to favor lightning production. Yet no convective available potential energy (CAPE) appears with either composite approach, which concurs with previous studies. While several of the composite members feature CAPE for elevated layers, the majority do not, suggesting that other processes (e.g., the release of symmetric instability), which are difficult to assess from a single sounding, tend to be at work.
Market, Patrick S.; Oravetz, Angela M.; Gaede, David; Bookbinder, Evan; Lupo, Anthony R.; Melick, Christopher J.; Smith, Larry L.; Thomas, Rashida; Redburn, Rachel; Pettegrew, Brian P.; Becker, Amy E.
The "in vivo cryotechnique" (IVCT) is a new method of morphological analysis which has the advantage of freezing tissues in living animals without stopping their blood circulation. The purpose of this study was to investigate the effect of parathyroid hormone (PTH) on renal type II Na-Pi transporters (NaPi-IIa and NaPi-IIc) and "cryobiopsy" (CB) using special cryoforceps as a simple method of the IVCT. The kidney tissues were biopsied at various time points after PTH administration by CB using liquid nitrogen as the cryogen. By hematoxylin-eosin (HE) staining the kidney tissues, well-frozen areas without visible ice crystals were obtained in the tissue surface areas, and the brush border membrane (BBM) of proximal tubules was well preserved at a light microscopic level. Immunohistochemical evaluation showed that PTH downregulated NaPi-IIa and NaPi-IIc at the BBM, being controlled by a different mechanism. In this method, the PTH-induced internalization of NaPi-IIc from microvilli to subapical compartments was not observed in the tissue preparations. NaPi-IIc protein appears to be degraded in microvilli of the proximal tubular cells after the injection of PTH. We suggest that CB using liquid nitrogen is useful to investigate renal type II Na-Pi transporters at the light microscopic level. PMID:20299753
Matsumoto, Natsuki; Hemmi, Akihiro; Yamato, Hideyuki; Ohnishi, Ritsuko; Segawa, Hiroko; Ohno, Shinichi; Miyamoto, Ken-ichi
The number of revision total hip arthroplasties is expected to rise as the indications for arthroplasty will expand due to the aging population. The prevalence of extensive proximal femoral bone loss is expected to increase subsequently. The etiology of bone loss from the proximal femur after total hip arthroplasty is multifactorial. Stress shielding, massive osteolysis, extensive loosening and history of multiple surgeries consist the most common etiologies. Reconstruction of extensive bone loss of the proximal femur during a revision hip arthroplasty is a major challenge for even the most experienced orthopaedic surgeon. The amount of femoral bone loss and the bone quality of the remaining metaphyseal and diaphyseal bone dictate the selection of appropriate reconstructive option. These include the use of impaction allografting, distal press-fit fixation, allograft-prosthesis composites and tumor megaprostheses. This review article is a concise review of the current literature and provides an algorithmic approach for reconstruction of different types of proximal femoral bone defects. PMID:25405090
Sakellariou, Vasileios I; Babis, George C
A large number of serrated polyps with malignant potential in the proximal colon were underestimated using currently available criteria mostly based on architectural and cytological features, contributing to proximal interval colorectal cancers. Recently, increasing evidences indicate that BRAF(V600E) mutation is a specific molecular feature and driver of the serrated pathway, and proximal serrated polyps with BRAF(V600E) mutation have a high risk of progression to malignancy. We proposed that immunohistochemical detection of BRAF(V600E) using a BRAF(V600E) mutation-specific antibody is a feasible technique for reproducibly identifying proximal serrated polyps with malignant potential in clinical practice, which may need more aggressive treatment and vigilant clinical monitoring. PMID:25550768
Fu, Xiangsheng; Zhang, Xiaoyan
This dissertation presents an experimental and analytical study of the Vision Based Navigation system (VisNav). VisNav is a novel intelligent optical sensor system invented by Texas A&M University recently for autonomous proximity operations...
Du, Ju-Young
Shox2 function couples neural, muscular and skeletal development in the proximal forelimb
to the human SHOX gene, deficiencies of which cause the short stature in Turner, Langer and L├®ri┬ŁWeill syndromes. In order to understand in more detail the development of the proximal limb, we searched for Shox2
Cobb, John
In impaction grafting for revision joint arthroplasty, the morselized cancellous bone (MCB) ideally remodels into a new contiguous lattice. However, the use of biologically active factors may sometimes be indicated to enhance fusion. The purpose of this study was to determine the stability of femoral impaction graft constructs for which either only the proximal or distal half of the MCB volume was modeled as fused. Fusing the proximal half of the impaction graft volume resulted in a higher femoral stem stability than did fusing the distal half. This proximal graft fusion also resulted in a stem stability that was similar to that of fusing the entire graft. These results emphasize the importance of proximal fixation of an impaction grafted femoral stem. PMID:18534514
Heiner, Anneliese D.; Callaghan, John J.; Brown, Thomas D.
Myoelectric activity of the cecum and proximal loop of the ascending colon in the cow
Medicine and Surgery ABSTRACT Myoelectric Activity of the Cecum and proximal Loop of the Ascending Colon in the Cow. (May 1993) Adrian Steiner, Dr. Med. Vet. , University of Zurich, Switzerland Chair of Advisory Committee: Dr. A. J. Roussel Six...
Steiner, Adrian
3D Multi-Field Multi-Scale Features From Range Data In Spacecraft Proximity Operations
, Control, and Dynamics. 2 DARPA?s Orbital Express used a suite of algorithms and sensors to successfully per- form a series of supervised, semi-autonomous proximity operations. The Autonomous Rendezvous and Capture Sensor System (ARCSS [1]) included both...
Flewelling, Brien Roy
Proximity-dependent Pollen Performance in Silene vulgaris ME LANIE GLAETTLI1,
Proximity-dependent Pollen Performance in Silene vulgaris ME┬┤ LANIE GLAETTLI1, *, LUCA PESCATORE2 structure was investigated in a patchily distributed population of gynodioecious Silene vulgaris: Population structure, microsatellites, pollen performance, gynodioecy, Silene vulgaris. INTRODUCTION
Alvarez, Nadir
Proximity-Induced Superconductivity in Nanowires: Minigap State and Differential Magnetoresistance phase. Additionally, we detect periodic oscillations in the differential magnetoresistance. We suggest. Surprisingly, however, we observe unusual periodic oscillations in the differential magnetoresistance
Proximal Ejecta at Meteor Crater, Arizona: Discovery of Impact Melt-bearing Breccias
NASA Astrophysics Data System (ADS)
Impact melt-bearing breccias have been discovered within the proximal ejecta blanket of Meteor Crater, Arizona, for the first time. They contain melt derived from a combination of the projectile and various sedimentary target rocks, including carbonates.
Osinski, G. R.; Bunch, T. E.; Wittke, J.
A rare case of a peripheral pulmonary adenoid cystic carcinoma is presented. Histological examination after lobectomy showed pronounced submucosal invasion of the carcinoma to proximal bronchi. Images PMID:1849668
Inoue, H; Iwashita, A; Kanegae, H; Higuchi, K; Fujinaga, Y; Matsumoto, I
Parallel double-plate capacitive proximity sensor modelling based on effective theory
A semi-analytical model for a double-plate capacitive proximity sensor is presented according to the effective theory. Three physical models are established to derive the final equation of the sensor. Measured data are used to determine the coefficients. The final equation is verified by using measured data. The average relative error of the calculated and the measured sensor capacitance is less than 7.5%. The equation can be used to provide guidance to engineering design of the proximity sensors.
Li, Nan, E-mail: firstname.lastname@example.com; Zhu, Haiye; Wang, Wenyu; Gong, Yu [Research Center for Non-destructive Testing and Evaluation, Beijing University of Technology, Beijing100124 (China)] [Research Center for Non-destructive Testing and Evaluation, Beijing University of Technology, Beijing100124 (China)
L UBLINSKI A. E. (2003) Does geographic proximity matter? Evidence from clustered and non-clustered aeronautic firms in Germany, Reg. Studies 37 , 453-467. This paper analyses what types of inter-firm linkages are stronger between geographically proximate firms compared to distant firms. It compares survey results of clustered and dispersed firms in the German aeronautic (supplying) industry. Results show that geographic
Alf Erko Lublinski
Cubilin- and megalin-mediated uptake of albumin in cultured proximal tubule cells of opossum kidney
Cubilin- and megalin-mediated uptake of albumin in cultured proximal tubule cells of opossum kidney.BackgroundReabsorption of albumin from the glomerular filtrate occurs via receptor-mediated endocytosis in the proximal tubule. This process is initiated by binding of albumin in apical clathrin-coated pits, followed by endocytosis and degradation in lysosomes. Although binding sites have been characterized by kinetic studies, the receptors responsible for
Xiao Yue Zhai; Rikke Nielsen; Henrik Birn; Karina Drumm; Sigrid Mildenberger; Ruth Freudinger; Soren K. Moestrup; Pierre J. Verroust; Erik I. Christensen; Michael Gekle
Three edible wild mushrooms from Nigeria: Their proximate and mineral composition
The pilei (caps) and the stipes (stalks) of the button and early open-cap (cup) stages ofLentinus subnudus, Psathyrella atroumbonata andTermitomyces striatus were assayed separately for their proximate and mineral composition. The differences observed in the contents of some of the proximate components seem to be related to species and mushroom parts.P. atroumbonata was richest in crude and true protein,L. subnudus
F. V. Alofe; O. Odeyemi; O. L. Oke
Role of the proximal and distal stomach in mixed solid and liquid meal emptying
The role of the proximal and distal stomach in the emptying of solids and liquids from the stomach remains unclear. We have used a dual isotope technique to quantify proximal and distal stomach emptying of a solid (100 g of 99mTc labelled liver\\/ground beef) liquid (either 200 ml of normal saline (eight subjects) or 25% dextrose (seven subjects) labelled with
P J Collins; L A Houghton; N W Read; M Horowitz; B E Chatterton; R Heddle; J Dent
Radiological and Survival Comparison of Four Methods of Fixation of a Proximal Femoral Stem
We compared the radiological appearances and survival of four methods of fixation of a femoral stem in 538 hips after follow-up for five or ten years. The fixation groups were: 1) press-fit shot-blasted smooth Ti-Al-V stem; 2) press-fit shot-blasted proximally ridged stem; 3) proximal hydroxyapatite (HA) coating; and 4) cementing. Survival analysis at five to ten years showed better results
W. J. Donnelly; A. Kobayashi; M. A. R. Freeman; T. W. Chin; H. Yeo; G. Scott
Geometrical correction of the e-beam proximity effect for raster scan systems
Increasing demands on pattern fidelity and CD accuracy in e- beam lithography require a correction of the e-beam proximity effect. The new needs are mainly coming from OPC at mask level and x-ray lithography. The e-beam proximity limits the achievable resolution and affects neighboring structures causing under- or over-exposion depending on the local pattern densities and process settings. Methods to
Nikola Belic; Hans Eisenmann; Hans Hartmann; Thomas Waas
The C5a receptor is expressed by human renal proximal tubular epithelial cells
The C5a receptor is expressed by a variety of cell types. These studies demonstrate by immunohistochemistry that the receptor is present on the surface of proximal and distal tubular epithelial cells from normal kidney. In addition, the receptor was detected on transitional epithelial cells of the ureter and bladder. Primary proximal tubular cultures and a proximal tubular cell line both also expressed the C5a receptor, as demonstrated by immunofluorescence and by FACS analysis. The presence of mRNA encoding the receptor was confirmed by reverse transcriptase-polymerase chain reaction analysis. As opposed to its effect on glomerular mesangial cells, the receptor did not mediate a proliferative response by the proximal tubular cells. C5a also did not enhance the synthesis/secretion of transforming growth factor-beta 1, monocyte chemoattractant protein-1, platelet-derived growth factor-AB or tumour necrosis factor-alpha by cultured proximal tubular cells. Therefore, although the C5a receptor clearly is expressed by proximal tubular cells, clarification of its functional relevance on this cell type awaits further studies. PMID:10931135
Zahedi, R; Braun, M; Wetsel, R A; Ault, B H; Khan, A; Welch, T R; Frenzke, M; Davis, A E
Proximity to Sports Facilities and Sports Participation for Adolescents in Germany
Objectives To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany. Methods A sample of 1,768 adolescents aged 11¢17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities. Results The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively. Conclusions Improved proximity to gyms is likely to be more important for female adolescents living in rural areas. PMID:24675689
Reimers, Anne K.; Wagner, Matthias; Alvanides, Seraphim; Steinmayr, Andreas; Reiner, Miriam; Schmidt, Steffen; Woll, Alexander
NASA Astrophysics Data System (ADS)
Here, we present the first systematic study on the temperature dependence of the extension of the superconducting proximity effect in a 1-2 atomic layer thin metallic film, surrounding a superconducting Pb island. Scanning tunneling microscopy/spectroscopy (STM/STS) measurements reveal the spatial variation of the local density of state on the film from 0.38 up to 1.8 K. In this temperature range the superconductivity of the island is almost unaffected and shows a constant gap of a 1.20 ▒ 0.03 meV. Using a superconducting Nb-tip a constant value of the proximity length of 17 ▒ 3 nm at 0.38 and 1.8 K is found. In contrast, experiments with a normal conductive W-tip indicate an apparent decrease of the proximity length with increasing temperature. This result is ascribed to the thermal broadening of the occupation of states of the tip, and it does not reflect an intrinsic temperature dependence of the proximity length. Our tunneling spectroscopy experiments shed fresh light on the fundamental issue of the temperature dependence of the proximity effect for atomic monolayers, where the intrinsic temperature dependence of the proximity effect is comparably weak.
Stepniak, A.; Caminale, M.; Leon Vanegas, A. A.; Oka, H.; Sander, D.; Kirschner, J.