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1

Na+ electrochemical gradient and Na+-Ca2+ exchange in rat proximal tubule  

SciTech Connect

The basolateral cell membrane of the rat proximal tubule contains a Na+-Ca2+ exchanger that may participate in the regulation of cytosolic calcium (Cai) and Ca2+ transport. In this work, the activity and orientation of the Na+-Ca2+ exchanger was studied in rat proximal tubules. The experiments were based on the thermodynamic notion that the exchanger is driven by the prevalence of either of two electrochemical gradients, that for Na+ (delta mu Na+) or for Ca2+ (delta mu Ca2+). Reductions in delta mu Na+, achieved by lowering extracellular Na+ (Nao) from 150 to 15 mM, increased Cai, decreased 45Ca efflux, and increased 45Ca influx. These changes occurred concurrently. When delta mu Na+ was reduced by increasing intracellular Na+ (Nai) with 10(-3) M oubain, Cai also increased. The effect of ouabain was probably dependent on Nai accumulation because the surge in Cai was prevented by exposure of the tubules to 5 mM Nao before ouabain exposure. On the other hand, when delta mu Na+ was lowered mM Nao and then by reducing Nao to 15 mM, Cai rose in two additive stages. We conclude from these data that in the rat proximal tubule the basal state of the Na+-Ca2+ exchanger is in forward mode, Nao-Cai. Moreover, the function of the Na+-Ca2+ exchanger is in accord with predictions derived from a thermodynamic analysis of its function.

Dominguez, J.H.; Rothrock, J.K.; Macias, W.L.; Price, J. (Veterans Administration Medical Center, Indianapolis, IN (USA))

1989-10-01

2

Relationship between PPAR? activation and NO on proximal tubular Na+ transport in the rat  

Microsoft Academic Search

BACKGROUND: Nitric oxide (NO) regulates renal proximal tubular (PT) Na+ handling through modulation of Na+-K+ ATPase. Peroxisome Proliferator Activated Receptor? (PPAR?), a nuclear transcription factor, is expressed in PTs and has been reported to influence NO generation\\/activity in renal tissues. This study tested the hypothesis that PPAR? interacts with NO and thereby affects renal tubular Na+ transport. Urinary excretion of

Mohammad A Newaz; Kasturi Ranganna; Adebayo O Oyekan

2004-01-01

3

Moxonidine inhibits Na+\\/H+ exchange in proximal tubule cells and cortical collecting duct  

Microsoft Academic Search

Moxonidine inhibits Na+\\/H+ exchange in proximal tubule cells and cortical collecting duct. The imidazoline receptor agonist moxonidine has been recently introduced as an antihypertensive therapy. Imidazoline specific binding sites have also been found in the kidney. Moxonidine induced natriuresis and diuresis in clearance studies in rats. Related substances such as various guanidinium derivatives have been shown to inhibit Na+\\/H+ exchange

Eberhard Schlatter; Ieva Ankorina-Stark; Sabine Haxelmans; Helge Hohage

1997-01-01

4

Maturation of proximal straight tubule NaCl transport: role of thyroid hormone  

PubMed Central

We have recently demonstrated that the rates of both active and passive proximal straight tubule (PST) NaCl transport in neonatal rabbits were less than in adults. In this segment NaCl entry across the apical membrane is via parallel Na+/H+ and Cl?/OH? exchangers, which increases in activity with maturation. The present in vitro microperfusion study examined whether thyroid hormone plays a role in the maturational increase in PST NaCl transport. Neonatal and adult PST were perfused with a high-chloride-low bicarbonate solution without organic solutes, simulating late proximal tubule fluid. Thyroid hormone-treated neonates had a higher rate of PST total and passive NaCl transport. In 8-wk-old animals that were hypothyroid since birth, the maturational increase in total and passive NaCl transport was prevented. Thyroid treatment for 4 days in hypothyroid 8-wk-old rabbits increased the rate of both total and passive NaCl transport. The maturational increases in both Na+/H+ and Cl?/OH? exchange activities were blunted in 8-wk-old hypothyroid animals and increased to control levels with thyroid treatment. This study demonstrates that thyroid hormone is a factor responsible for the maturational increase in both active and passive PST NaCl transport.

SHAH, MEHUL; QUIGLEY, RAYMOND; BAUM, MICHEL

2014-01-01

5

Prenatal programming of rat proximal tubule Na+/H+ exchanger by dexamethasone  

PubMed Central

Prenatal administration of dexamethasone causes hypertension in rats when they are studied as adults. Although an increase in tubular sodium reabsorption has been postulated to be a factor programming hypertension, this has never been directly demonstrated. The purpose of this study was to examine whether prenatal programming by dexamethasone affected postnatal proximal tubular transport. Pregnant Sprague-Dawley rats were injected with intraperitoneal dexamethasone (0.2 mg/kg) daily for 4 days between the 15th and 18th days of gestation. Prenatal dexamethasone resulted in an elevation in systolic blood pressure when the rats were studied at 7–8 wk of age compared with vehicle-treated controls: 131 ± 3 vs. 115 ± 3 mmHg (P < 0.001). The rate of proximal convoluted tubule volume absorption, measured using in vitro microperfusion, was 0.61 + 0.07 nl·mm?1·min?1 in control rats and 0.93 + 0.07 nl·mm?1·min?1 in rats that received prenatal dexamethasone (P < 0.05). Na+/H+ exchanger activity measured in perfused tubules in vitro using the pH-sensitive dye BCECF showed a similar 50% increase in activity in proximal convoluted tubules from rats treated with prenatal dexamethasone. Although there was no change in abundance of NHE3 mRNA, the predominant luminal proximal tubule Na+/H+ exchanger, there was an increase in NHE3 protein abundance on brush-border membrane vesicles in 7- to 8-wk-old rats receiving prenatal dexamethasone. In conclusion, prenatal administration of dexamethasone in rats increases proximal tubule transport when rats are studied at 7–8 wk old, in part by stimulating Na+/H+ exchanger activity. The increase in proximal tubule transport may be a factor mediating the hypertension by prenatal programming with dexamethasone.

Dagan, Amit; Gattineni, Jyothsna; Cook, Vodi; Baum, Michel

2014-01-01

6

Na,K-ATPase activity and 25(OH)vitamin D 3 hydroxylation in rat proximal tubules  

Microsoft Academic Search

The proximal tubule is the target site for parathyroid hormone (PTH), and conversion of 25(OH)vitamin D3 hormones which impinge on calcium (Ca) homeostatis, as well as a major site for sodium (Na) reabsorption. The effect of changes in PTH and vitamin D status on Na,K-ATPase activity, as a measure of Na transport, were studied in the proximal tubules of adult

Deborah Elstein; Justin Silver

1986-01-01

7

Asymmetric distribution of the Na+/H+ antiporter in the renal proximal tubule epithelial cell.  

PubMed

The subcellular distribution of the Na+/H+ antiporter in renal proximal tubule cells was studied with differential and density gradient centrifugation. Enzyme markers for basolateral membranes [Na+/K+)-ATPase), brush border membranes (maltase), and a variety of intracellular organelles (NADPH cytochrome c reductase, thiamine pyrophosphatase, acid phosphatase, and succinate cytochrome c reductase) were simultaneously assayed in sucrose density gradients. Basolateral membranes (median rho = 1.150) were well separated from brush border membranes (median rho = 1.165) by this technique. Markers for other cellular organelles had intermediate or bimodal distributions. To determine the cellular location of the Na+/H+ antiporter, Na+-dependent collapse of preformed pH gradients was assayed in the sucrose density gradient fractions using acridine orange. Na+/H+ antiporter activity paralleled the distribution of the brush border membrane fractions; activity in the peak basolateral membrane fraction was less than 5% of that in the peak brush border fraction. To determine whether antiporter activity was potentially detectable in all cell fractions, nigericin was added to each fraction and K+/H+ exchange was assayed with acridine orange. Activity was present in all sucrose density gradient fractions. In addition, there was no alteration in Na+/H+ exchange activity measured in brush border membranes after mixing with cell sol or basolateral membranes, showing that neither inhibitors nor activators of the Na+/H+ antiporter were present in any of the cell fractions. These controls confirmed the finding that Na+/H+ antiporter activity was absent from basolateral membranes. The presence of the Na+/H+ antiporter in brush border membranes and its absence from basolateral membranes is consistent with its playing an important role in the vectorial transport of H+ from blood to tubular lumen in the renal proximal tubule. PMID:6315699

Ives, H E; Yee, V J; Warnock, D G

1983-11-25

8

Fructose stimulates Na/H exchange activity and sensitizes the proximal tubule to angiotensin II.  

PubMed

The proximal nephron reabsorbs 60% to 70% of the fluid and sodium and most of the filtered bicarbonate via Na/H exchanger 3. Enhanced proximal nephron transport is implicated in hypertension. Our findings show that a fructose-enriched diet causes salt sensitivity. We hypothesized that fructose stimulates luminal Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. Na/H exchange was measured in rat proximal tubules as the rate of intracellular pH (pHi) recovery in fluorescent units/s. Replacing 5 mmol/L glucose with 5 mmol/L fructose increased the rate of pHi recovery (1.8±0.6 fluorescent units/s; P<0.02; n=8). Staurosporine, a protein kinase C inhibitor, blocked this effect. We studied whether this effect was because of the addition of fructose or removal of glucose. The basal rate of pHi recovery was first tested in the presence of a 0.6-mmol/L glucose and 1, 3, or 5 mmol/L fructose added in a second period. The rate of pHi recovery did not change with 1 mmol/L but it increased with 3 and 5 mmol/L of fructose. Adding 5 mmol/L glucose caused no change. Removal of luminal sodium blocked pHi recovery. With 5.5 mmol/L glucose, angiotensin II (1 pmol/L) did not affect the rate of pHi recovery (change, -1.1±0.5 fluorescent units/s; n=9) but it increased the rate of pHi recovery with 0.6 mmol/L glucose/5 mmol/L fructose (change, 4.0±2.2 fluorescent units/s; P<0.02; n=6). We conclude that fructose stimulates Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. This mechanism is likely dependent on protein kinase C. These results may partially explain the mechanism by which a fructose diet induces hypertension. PMID:24379189

Cabral, Pablo D; Hong, Nancy J; Hye Khan, Md Abdul; Ortiz, Pablo A; Beierwaltes, William H; Imig, John D; Garvin, Jeffrey L

2014-03-01

9

Dopamine fails to inhibit Na,H-exchanger in proximal tubules of obese Zucker rats.  

PubMed

Dopamine via the activation of D1-like receptors inhibits Na,K-ATPase and Na,H-exchanger and subsequently increases sodium excretion. We have previously reported that dopamine failed to inhibit Na,K-ATPase in the proximal tubules (PTs) of obese Zucker rats. The present study was designed to determine the effect of dopamine on Na,H-exchanger in PTs of lean and obese Zucker rats, and examine D1-like receptor-coupled signal transduction pathway mediating the inhibition of Na,H-exchanger. We found that dopamine inhibited Na,H-exchanger in the PTs of lean rats but this response was absent in obese rats. In brush border membranes, [3H]SCH 23390 binding revealed a approximately 45% reduction in D1-like receptor binding sites in obese compared to lean rats. Dopamine stimulated cAMP accumulation in PTs of lean but not in obese rats. Forskolin-mediated stimulation of cAMP was similar in lean and obese rats. Dopamine as well as forskolin and dibutyryl cAMP-mediated stimulation of protein kinase A (PKA) was reduced in PTs of obese compared to lean rats. The data suggest that reduction in D1-like receptor binding sites, defective coupling with signaling pathway and inability of PKA activation may be responsible for the failure of dopamine to inhibit Na,H-exchanger in PTs of obese rats. This phenomenon may contribute to an increase in sodium reabsorption and development of hypertension in obese Zucker rats. PMID:11728004

Hussain, T; Becker, M; Beheray, S; Lokhandwala, M F

2001-11-01

10

Reduction of renal triglyceride accumulation: effects on proximal tubule Na+/H+ exchange and urinary acidification  

PubMed Central

One main pathophysiological mechanism underlying the increased risk for uric acid nephrolithiasis in humans with the metabolic syndrome is the excretion of unduly acidic urine, in part because of reduced excretion of the main urinary buffer, ammonium. The Zucker diabetic fatty (ZDF) rat, an established rodent model of the metabolic syndrome, has similar urinary abnormalities, attributed in part to lower expression and activity of the principal mediator of proximal tubule ammonium excretion, brush-border membrane Na+/H+ exchanger 3 (NHE3). These defects are associated with renal tubular steatosis in ZDF rats, but the causal relationship between renal steatosis and defective urinary acidification has not been investigated in vivo. We hypothesized that reduction of renal steatosis would commensurately normalize urinary acidification parameters. We treated ZDF rats with thiazolidinediones to reduce nonadipose tissue steatosis. Four weeks of treatment reduced renal triglyceride accumulation and restored urinary acidification parameters in ZDF rats to levels comparable to their lean littermates; urinary acidification was not affected by treatment in lean rats. To further document the direct effects of fat, we showed that functional abnormalities induced by fat loading in a cell culture model of proximal tubule steatosis and lipotoxicity can be reversed by fat removal but not by thiazolidinediones alone. Together, these findings support the causative role of renal steatosis in the pathogenesis of urinary acidification defects, demonstrate reversibility upon lipid removal, and highlight a potential therapeutic strategy for renal abnormalities in the metabolic syndrome.

Bobulescu, I. Alexandru; Dubree, Michele; Zhang, Jianning; McLeroy, Paul

2009-01-01

11

Phospholemman regulates cardiac Na+/Ca2+ exchanger by interacting with the exchanger's proximal linker domain.  

PubMed

Phospholemman (PLM) belongs to the FXYD family of small ion transport regulators. When phosphorylated at Ser(68), PLM inhibits cardiac Na(+)/Ca(2+) exchanger (NCX1). We previously demonstrated that the cytoplasmic tail of PLM interacts with the proximal intracellular loop (residues 218-358), but not the transmembrane (residues 1-217 and 765-938) or Ca(2+)-binding (residues 371-508) domains, of NCX1. In this study, we used intact Na(+)/Ca(2+) exchanger with various deletions in the intracellular loop to map the interaction sites with PLM. We first demonstrated by Western blotting and confocal immunofluorescence microscopy that wild-type (WT) NCX1 and its deletion mutants were expressed in transfected HEK-293 cells. Cotransfection with PLM and NCX1 (or its deletion mutants) in HEK-293 cells did not decrease expression of NCX1 (or its deletion mutants). Coexpression of PLM with WT NCX1 inhibited NCX1 current (I(NaCa)). Deletion of residues 240-679, 265-373, 250-300, or 300-373 from WT NCX1 resulted in loss of inhibition of I(NaCa) by PLM. Inhibition of I(NaCa) by PLM was preserved when residues 229-237, 270-300, 328-330, or 330-373 were deleted from the intracellular loop of NCX1. These results suggest that PLM mediated inhibition of I(NaCa) by interacting with two distinct regions (residues 238-270 and 300-328) of NCX1. Indeed, I(NaCa) measured in mutants lacking residues 238-270, 300-328, or 238-270 + 300-328 was not affected by PLM. Glutathione S-transferase pull-down assays confirmed that PLM bound to fragments corresponding to residues 218-371, 218-320, 218-270, 238-371, and 300-373, but not to fragments encompassing residues 250-300 and 371-508 of NCX1, indicating that residues 218-270 and 300-373 physically associated with PLM. Finally, acute regulation of I(NaCa) by PLM phosphorylation observed with WT NCX1 was absent in 250-300 deletion mutant but preserved in 229-237 deletion mutant. We conclude that PLM mediates its inhibition of NCX1 by interacting with residues 238-270 and 300-328. PMID:19158404

Zhang, Xue-Qian; Wang, Jufang; Carl, Lois L; Song, Jianliang; Ahlers, Belinda A; Cheung, Joseph Y

2009-04-01

12

Phosphoinositide Binding Differentially Regulates NHE1 Na+/H+ Exchanger-dependent Proximal Tubule Cell Survival*  

PubMed Central

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.

Abu Jawdeh, Bassam G.; Khan, Shenaz; Deschenes, 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.

2011-01-01

13

Dopamine acutely decreases apical membrane Na/H exchanger NHE3 protein in mouse renal proximal tubule  

PubMed Central

Background Dopamine is a principal natriuretic hormone in mammalian Na+ homeostasis. Dopamine acutely alters glomerular filtration rate (GFR) and decreases Na+ absorption in both the proximal and distal nephron. Proximal tubule natriuresis is effected through inhibition of the apical membrane Na/H exchanger NHE3. Methods We examined whether dopamine directly and acutely decreases apical membrane NHE3 protein using renal tissue in two in vitro systems: renal cortical slices and in vitro perfused single tubules. After incubation with dopamine, NHE3 activitry was measured by 22Na flux and NHE3 antigen was measured by immunoblot in apical membrane and total cellular membranes. Results Direct application of dopamine to either cortical slices or microperfused tubules acutely decreases NHE3 activity and antigen at the apical membrane of the proximal tubule. No change in total cellular NHE3 was detected. Conclusion One mechanism by which dopamine causes natriuresis is via direct and acute reduction of NHE3 protein at the apical membrane via changes in NHE3 protein trafficking.

Bacic, Desa; Kaissling, Brigitte; McLeroy, Paul; Zou, Lixian; Baum, Michel; Moe, Orson W.

2014-01-01

14

Effect of renal lipid accumulation on proximal tubule Na+/H+ exchange and ammonium secretion  

PubMed Central

Patients with metabolic syndrome have increased risk of uric acid nephrolithiasis due to lower urinary pH and impaired ammonium excretion. The pathophysiology underlying these urinary changes is unknown. We used two animal models and a cell culture model to study whether the alteration in renal acidification is associated with renal fat infiltration (steatosis). Compared with pair-fed lean control rats, Zucker diabetic fatty rats have higher renal triglyceride content, decreased urinary ammonium and pH, and lower levels of brush border membrane Na+/H+ exchanger-3 (NHE3), a major mediator of ammonium excretion. High-fat feeding in Sprague-Dawley rats results in transient lowering of urinary ammonium and pH, with all parameters returning to normal when the animals resumed eating normal chow. This is consistent with an absence of diet-induced renal steatosis in these animals. To examine the direct effect of fat accumulation, we incubated opossum kidney (OKP) cells with a mixture of long-chain fatty acids and found accumulation of intracellular lipids with concomitant dose-dependent decrease in NHE3 activity, surface biotin-accessible NHE3 protein, and ammonium secretion. A lower dose of fatty acids that leads to intracellular lipid accumulation but does not change baseline NHE3 is sufficient to abolish the stimulation of NHE3 by insulin and to partially block the stimulation of NHE3 by glucocorticoid hormones; acid regulation of NHE3 in lipid-loaded OKP cells is not affected. These findings suggest that renal steatosis decreases ammonium secretion in the proximal tubule, in part by reducing NHE3 activity and by impairing the regulation of NHE3 by specific agonists.

Bobulescu, I. Alexandru; Dubree, Michele; Zhang, Jianning; McLeroy, Paul; Moe, Orson W.

2010-01-01

15

Phospholemman regulates cardiac Na+/Ca2+ exchanger by interacting with the exchanger's proximal linker domain  

PubMed Central

Phospholemman (PLM) belongs to the FXYD family of small ion transport regulators. When phosphorylated at Ser68, PLM inhibits cardiac Na+/Ca2+ exchanger (NCX1). We previously demonstrated that the cytoplasmic tail of PLM interacts with the proximal intracellular loop (residues 218–358), but not the transmembrane (residues 1–217 and 765–938) or Ca2+-binding (residues 371–508) domains, of NCX1. In this study, we used intact Na+/Ca2+ exchanger with various deletions in the intracellular loop to map the interaction sites with PLM. We first demonstrated by Western blotting and confocal immunofluorescence microscopy that wild-type (WT) NCX1 and its deletion mutants were expressed in transfected HEK-293 cells. Cotransfection with PLM and NCX1 (or its deletion mutants) in HEK-293 cells did not decrease expression of NCX1 (or its deletion mutants). Coexpression of PLM with WT NCX1 inhibited NCX1 current (INaCa). Deletion of residues 240–679, 265–373, 250–300, or 300–373 from WT NCX1 resulted in loss of inhibition of INaCa by PLM. Inhibition of INaCa by PLM was preserved when residues 229–237, 270–300, 328–330, or 330–373 were deleted from the intracellular loop of NCX1. These results suggest that PLM mediated inhibition of INaCa by interacting with two distinct regions (residues 238–270 and 300–328) of NCX1. Indeed, INaCa measured in mutants lacking residues 238–270, 300–328, or 238–270 + 300–328 was not affected by PLM. Glutathione S-transferase pull-down assays confirmed that PLM bound to fragments corresponding to residues 218–371, 218–320, 218–270, 238–371, and 300–373, but not to fragments encompassing residues 250–300 and 371–508 of NCX1, indicating that residues 218–270 and 300–373 physically associated with PLM. Finally, acute regulation of INaCa by PLM phosphorylation observed with WT NCX1 was absent in 250–300 deletion mutant but preserved in 229–237 deletion mutant. We conclude that PLM mediates its inhibition of NCX1 by interacting with residues 238–270 and 300–328.

Zhang, Xue-Qian; Wang, JuFang; Carl, Lois L.; Song, Jianliang; Ahlers, Belinda A.; Cheung, Joseph Y.

2009-01-01

16

Angiotensin II activates the ouabain-insensitive Na +ATPase from renal proximal tubules through a G-protein  

Microsoft Academic Search

Angiotensin II (AG II) stimulates the ouabain-insensitive, furosemide- sensitive Na+-ATPase present in the basolateral membrane of pig renal proximal tubules in a dose dependent manner. Maximum effect was obtained with 10?8 M AG II, which corresponded to an activity 134% higher than control. Half of the maximum effect was observed between 10?11 M and 10?10 M, corresponding to physiological hormone

L. B. A. Rangel; C. Caruso-Neves; L. S. Lara; F. L. Brasil; A. G. Lopes

1999-01-01

17

Phosphorylation-dependent differences in the activation properties of distal and proximal dendritic Na+ channels in rat CA1 hippocampal neurons.  

PubMed

At distal dendritic locations, the threshold for action potential generation is higher and the amplitude of back-propagating spikes is decreased. To study whether these characteristics depend upon Na+ channels, their voltage-dependent properties at proximal and distal dendritic locations were compared in CA1 hippocampal neurons. Distal Na+ channels activated at more hyperpolarized voltages than proximal (half-activation voltages were -20.4 +/- 2.4 mV vs. -12.0 +/- 1.7 mV for distal and proximal patches, respectively, n = 16, P < 0.01), while inactivation curves were not significantly different. The resting membrane potential of distal regions also appeared to be slightly but consistently more hyperpolarized than their proximal counterpart. Staurosporine, a non-selective protein kinase inhibitor, shifted the activation curves for both proximal and distal Na+ channels to the left so that they overlapped and also caused the resting potentials to be comparable. Staurosporine affected neither the inactivation kinetics of Na+ currents nor the reversal potential for Na+. These results suggest that the difference in the voltage dependence of activation of distal and proximal Na+ channels can be attributed to a different phosphorylation state at the two locations. PMID:12068031

Gasparini, Sonia; Magee, Jeffrey C

2002-06-15

18

Stimulation of Na+/H+ antiport is an early event in hypertrophy of renal proximal tubular cells.  

PubMed Central

Renal hypertrophy in vivo is achieved by an increase in protein content per cell and an increase in cell size with minimal hyperplasia. Hypertrophied renal tubular cells remain quiescent and demonstrate an increase in transcellular transport rates. This situation was simulated in vitro by exposing a confluent, quiescent primary culture of rabbit renal proximal tubular cells to either insulin, prostaglandin E1, or hypertonic NaCl for 24 or 48 hr. Protein per cell increased by 20-30% with little or no increase in [3H]thymidine incorporation into DNA. Mean cell volume was also increased in insulin- and hypertonic NaCl-treated but not in prostaglandin E1-treated cells. The lag period required to initiate DNA synthesis by a combination of insulin and hydrocortisone was the same in control and hypertrophied cells, indicating a quiescent state of the latter. Two hours of exposure to the growth stimuli increased amiloride-sensitive Na+ uptake, Na-dependent H+ efflux, and ouabain-sensitive Rb+ uptake, indicating that stimulation of Na+/H+ antiport (exchange) occurs as an early event in their action. Hypertrophied cells continued to demonstrate enhanced Na+/H+ antiport after the growth stimuli were removed for 3 hr, by which time their acute effects are reversed.

Fine, L G; Badie-Dezfooly, B; Lowe, A G; Hamzeh, A; Wells, J; Salehmoghaddam, S

1985-01-01

19

Perinatal Na+ Overload Programs Raised Renal Proximal Na+ Transport and Enalapril-Sensitive Alterations of Ang II Signaling Pathways during Adulthood  

PubMed Central

Background High Na+ intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na+ overload-programmed alterations in Na+ transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. Methodology/Principal Findings Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na++K+)ATPase expression and activity. Ouabain-insensitive Na+-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT2 receptor expression decreased while AT1 expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na++K+)ATPase, partially recovered the response of Na+-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na+ or not. In addition, treatment with enalapril per se reduced AT2 receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na+-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. Conclusions/Significance Maternal Na+ overload programmed alterations in renal Na+ transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril was beneficial predominantly through its influence on Na+ pumping activities in adult offspring. However, side effects including down-regulation of PKA, PKC and AT2 receptors and increased TBARS could impair renal function in later life.

Cabral, Edjair V.; Vieira-Filho, Leucio D.; Silva, Paulo A.; Nascimento, Williams S.; Aires, Regina S.; Oliveira, Fabiana S. T.; Luzardo, Ricardo; Vieyra, Adalberto; Paixao, Ana D. O.

2012-01-01

20

Specific association of megalin and the Na+/H+ exchanger isoform NHE3 in the proximal tubule.  

PubMed

We investigated whether the renal brush border Na+/H+ exchanger NHE3 exists in assemblies with other proteins in native kidney membranes. To this end we generated monoclonal antibodies (mAbs) against affinity purified NHE3 protein complexes. Hybridomas were selected based on ability to immunoprecipitate NHE3. One of the resulting mAbs (10A3) labeled a high molecular mass (>200 kDa) protein and stained primarily the coated pit region of the proximal tubule in a manner similar to that described for megalin (gp330). We then confirmed that both mAb 10A3 and a known anti-megalin mAb immunoprecipitated and immunoblotted the same protein, namely megalin. mAb 10A3 specifically co-precipitated NHE3 but not villin or NaPi-2 from solubilized renal membranes, indicating specificity of the NHE3-megalin interaction. When immunoprecipitations were performed using either 10A3 or anti-NHE3 mAb 2B9 after separation of solubilized renal proteins by sucrose velocity gradient centrifugation, we found that NHE3 exists in two states with distinct sedimentation coefficients, a 9.6 S megalin-free form and a 21 S megalin-bound form, and that when NHE3 assembles with megalin, epitopes within the carboxyl-terminal 131 amino acids of NHE3 are blocked. Taken together, these findings indicate that a significant pool of NHE3 exists as a multimeric complex with megalin in the brush border of the proximal tubule. PMID:10364184

Biemesderfer, D; Nagy, T; DeGray, B; Aronson, P S

1999-06-18

21

Role of H 2O 2 on the kinetics of low-affinity high-capacity Na +-dependent alanine transport in SHR proximal tubular epithelial cells  

Microsoft Academic Search

The presence of high and low sodium affinity states for the Na+-dependent [14C]-l-alanine uptake in immortalized renal proximal tubular epithelial (PTE) cells was previously reported (Am. J. Physiol. 293 (2007) R538–R547). This study evaluated the role of H2O2 on the Na+-dependent [14C]-l-alanine uptake of ASCT2 in immortalized renal PTE cells from Wistar Kyoto rat (WKY) and spontaneously hypertensive rat (SHR).

Vanda Pinto; Maria João Pinho; Pedro. A. Jose; Patrício Soares-da-Silva

2010-01-01

22

Barium- or quinine-induced depolarization activates K+, Na+ and cationic conductances in frog proximal tubular cells.  

PubMed

1. Frog proximal tubular cells were fused into giant cells. We measured membrane potential (Vm), its changes (delta Vm), and current-induced voltage changes (delta psi) in single cells, during control and experimental states. Each cell served as its own control. 2. In the presence of a physiological Ringer solution, the transference number for potassium (tK) was 0.50. Barium (3 mM) reduced membrane conductance (Gm) by 50%; low-Cl- solutions and low-Na+ solutions also diminished Gm, by 52 and 30%, respectively. The association of barium and low-NaCl solutions decreased Gm to approximately 38% of control, indicating that the impermeant substitute of a physiological ion may interact with other pathways; alternatively, blockade of steady-state conductances may activate physiologically silent processes. 3. In an attempt to enhance the contribution of the partial K+ conductance (GK) to Gm, fused cells were exposed to low-Cl- solutions, containing in addition 0.1 mM-methazolamide, to inhibit the rheogenic Na(+)-HCO3-symport, and 1 microM-amiloride, to block Na+ conductance (GNa). tK went up to 0.83. 4. The high tK preparation was challenged with barium (3 mM) or quinine (Quin, 1 mM). These blockers produced large depolarizations (approximately 60 mV), however, although Gm decreased along early- and mid-depolarization, Gm plateaued and eventually it increased with larger and larger depolarization. 5. Depolarization-associated increase in Gm reflects activation of other conductances. These are Na+, cationic, and K+ conductance(s) poorly sensitive to quinine or barium. In the presence of Ba(2+)- or Quin-induced depolarization, injection of depolarizing current produces delayed increase in conductance. 6. Depolarization-induced activation of cationic conductance (Gcat) and GNa results in enlargement of the K+ electrochemical potential difference, to about 70 mV; this difference allows recycling of K+ ions outwards, since a GK is still detected and may contribute up to 38% of the total conductance. PMID:1317443

Discala, F; Belachgar, F; Planelles, G; Hulin, P; Anagnostopoulos, T

1992-03-01

23

Conductive Na/sup +/ transport in an epithelial cell line (LLC-PK/sub 1/) with characteristics of proximal tubular cells  

SciTech Connect

/sup 22/Na influx and efflux from confluent monolayers of an epithelial cell line with multiple differentiated characteristics of the straight segment of the renal proximal tubule were studied in the presence and absence of a pH gradient. The results show that /sup 22/Na/sup +/ influx in the absence of a pH gradient is inhibited by amiloride as well as by complete replacement of Cl/sup -/ by an impermeable anion, such as isethionate. Dissipation of cell membrane potential by increasing the potassium concentration of the extracellular medium in the presence of valinomycin also inhibited Na/sup +/ influx, whereas sodium influx induced by an H/sup +/ gradient was not affected. Inhibition of Na/sup +/ influx by different maneuvers produced hyperpolarization of the plasma cell membrane, as would be expected if the sodium movement involved net displacement of charges. Calcium and other divalent and trivalent cations also inhibited Na/sup +/ influx measured in the absence of an H/sup +/ gradient. Na/sup +/ influx induced by a pH gradient, however, was not affected. Like the Na/sup +/-H/sup +/-exchange system, the conductive Na/sup +/ pathway is localized in the apical membrane of the epithelial cells. From these results, the authors conclude that at least a fraction of transepithelial Na/sup +/ transport in LLC-PK/sub 1/ monolayers occurs through a simple rheogenic transport system.

Cantiello, H.F.; Scott, J.A.; Rabito, C.A.

1987-04-01

24

Clonal analysis of immortalized renal proximal tubule cells: Na(+)/glucose cotransport system levels are maintained despite a decline in transport function.  

PubMed

Primary rabbit kidney proximal tubule (RPT) cells (S.D. Chung et al., 1982, J. Cell Biol. 95, 118-126) were transfected with the vector pRSV-T, which contains SV40 early region genes. After the third passage (when normal cells had stopped dividing), individual colonies formed in cultures transfected with pRSV-T. Clonal isolates (RPT-I cells) could be obtained in a simple and reproducible manner. Southern analysis of clone RPT-I8 indicated the presence of SV40 early region genes. Nuclear SV40 T was detected. After 23 passages, and subcloning, RPT-I8 (and subclones) was found to express renal proximal tubule markers to a similar extent, indicating that the phenotype was stable. Nevertheless, the activities of the Na(+)/glucose cotransport system, gamma-glutamyl transpeptidase and alkaline phosphatase, were reduced as compared with primary cultures. Western analysis indicated that the level of Na(+)/glucose cotransporters was maintained in RPT-I8 cells, when compared with intact proximal tubules and primary cultures. Thus, the reduction in alpha-MG uptake in RPT-I8 cells may be attributed to other types of cellular alterations, including changes in energy metabolism. Indeed, growth in glucose-free medium was not observed in RPT-I8 cell cultures, suggesting that unlike primary RPT cells (J. C. Chung et al., 1992, J. Cell. Physiol. 150, 243-250), the gluconeogenic pathway was not intact. PMID:12460651

Taub, Mary; Han, Ho Jae; Rajkhowa, Trivikram; Allen, Cheryl; Park, Jun Hong

2002-12-10

25

Role of H(2)O(2) on the kinetics of low-affinity high-capacity Na(+)-dependent alanine transport in SHR proximal tubular epithelial cells.  

PubMed

The presence of high and low sodium affinity states for the Na(+)-dependent [(14)C]-l-alanine uptake in immortalized renal proximal tubular epithelial (PTE) cells was previously reported (Am. J. Physiol. 293 (2007) R538-R547). This study evaluated the role of H(2)O(2) on the Na(+)-dependent [(14)C]-l-alanine uptake of ASCT2 in immortalized renal PTE cells from Wistar Kyoto rat (WKY) and spontaneously hypertensive rat (SHR). Na(+) dependence of [(14)C]-l-alanine uptake was investigated replacing NaCl with an equimolar concentration of choline chloride in vehicle- and apocynin-treated cells. Na(+) removal from the uptake solution abolished transport activity in both WKY and SHR PTE cells. Decreases in H(2)O(2) levels in the extracellular medium significantly reduced Na(+)-K(m) and V(max) values of the low-affinity high-capacity component in SHR PTE cells, with no effect on the high-affinity low-capacity state of the Na(+)-dependent [(14)C]-l-alanine uptake. After removal of apocynin from the culture medium, H(2)O(2) levels returned to basal values within 1 to 3h in both WKY and SHR PTE cells and these were found stable for the next 24h. Under these experimental conditions, the Na(+)-K(m) and V(max) of the high-affinity low-capacity state were unaffected and the low-affinity high-capacity component remained significantly decreased 1day but not 4days after apocynin removal. In conclusion, H(2)O(2) in excess is required for the presence of a low-affinity high-capacity component for the Na(+)-dependent [(14)C]-l-alanine uptake in SHR PTE cells only. It is suggested that Na(+) binding in renal ASCT2 may be regulated by ROS in SHR PTE cells. PMID:20599757

Pinto, Vanda; Pinho, Maria João; Jose, Pedro A; Soares-da-Silva, Patrício

2010-07-30

26

Effects of Acetazolamide on Proximal Tubule Cl, Na, and HCO3 Transport in Normal and Acidotic Dogs during Distal Blockade  

PubMed Central

It has been suggested that the establishment of a tubular fluid to plasma chloride gradient in the late proximal tubule by the reabsorption of bicarbonate (and other anions) in the early proximal tubule is responsible for a significant part of sodium chloride and water reabsorption in the proximal tubule. In the present study the effects of acetazolamide on proximal tubule water and electrolyte excretion were examined in 6 normal dogs and 10 chronic ammonium chloride-loaded dogs during distal blockade produced by ethacrynic acid and chlorothiazide administration. During distal blockade control urine/plasma osmolality and urine/plasma sodium were close to unity in all experiments. Urine/plasma chloride and urine/plasma bicarbonate were 1.21±0.02 and 0.75±0.07 in normal and 1.24±0.01 and 0.04±0.01 in acidotic dogs, respectively. After the administration of acetazolamide (20 mg/kg i.v.), there was a significant increase in urine flow, absolute and fractional excretion of sodium, bicarbonate, and chloride in all animals. Associated with these effects, urine/plasma osmolality and urine/plasma sodium remained unchanged but urine/plasma chloride decreased significantly to 1.15±0.01 in normal and to 1.19±0.01 in acidotic dogs. In acidotic dogs there was a significant correlation between the increase in bicarbonate, sodium, or chloride excretion after acetazolamide and the plasma bicarbonate level (range 6.8-12.5 meq/liter). These data demonstrate a significant effect of acetazolamide on bicarbonate, sodium, and chloride reabsorption in the proximal tubule even in the face of severe acidosis. Moreover, the data suggest that the decrease in chloride reabsorption (and accompanying sodium) after acetazolamide is related to the decrease in bicarbonate reabsorption and the associated decrease in the transtubular chloride gradient.

Chou, Shyan-Yih; Porush, Jerome G.; Slater, Paul A.; Flombaum, Carlos D.; Shafi, Tahir; Fein, Paul A.

1977-01-01

27

Inhibition of Na+-H+ exchange impairs receptor-mediated albumin endocytosis in renal proximal tubule-derived epithelial cells from opossum.  

PubMed

1. Receptor-mediated endocytosis is an important mechanism for transport of macromolecules and regulation of cell-surface receptor expression. In renal proximal tubules, receptor-mediated endocytosis mediates the reabsorption of filtered albumin. Acidification of the endocytic compartments is essential because it interferes with ligand-receptor dissociation, vesicle trafficking, fusion events and coat formation. 2. Here we show that the activity of Na+-H+ exchanger isoform 3 (NHE3) is important for proper receptor-mediated endocytosis of albumin and endosomal pH homeostasis in a renal proximal tubular cell line (opossum kidney cells) which expresses NHE3 only. 3. Depending on their inhibitory potency with respect to NHE3 and their lipophilicity, the NHE inhibitors EIPA, amiloride and HOE694 differentially reduced albumin endocytosis. The hydrophilic inhibitor HOE642 had no effect. 4. Inhibition of NHE3 led to an alkalinization of early endosomes and to an acidification of the cytoplasm, indicating that Na+-H+ exchange contributes to the acidification of the early endosomal compartment due to the existence of a sufficient Na+ gradient across the endosomal membrane. 5. Exclusive acidification of the cytoplasm with propionic acid or by removal of Na+ induced a significantly smaller reduction in endocytosis than that induced by inhibition of Na+-H+ exchange. 6. Analysis of the inhibitory profiles indicates that in early endosomes and endocytic vesicles NHE3 is of major importance, whereas plasma membrane NHE3 plays a minor role. 7. Thus, NHE3-mediated acidification along the first part of the endocytic pathway plays an important role in receptor-mediated endocytosis. Furthermore, the involvement of NHE3 offers new ways to explain the regulation of receptor-mediated endocytosis. PMID:10545138

Gekle, M; Drumm, K; Mildenberger, S; Freudinger, R; Gassner, B; Silbernagl, S

1999-11-01

28

PROXIMITY POLITICS  

Microsoft Academic Search

'Proximity politics' refers to a certain set of new political–cultural problems and issues that the globalization process confronts us with. Specifically it refers to the sort of engagements globalization entails as it draws us all closer together: both 'structurally', via the complex institutional interconnections of globalization, and 'phenomenologically' via the sort of experienced proximity that is provided in time-space bridging

John Tomlinson

2000-01-01

29

Proximal Nephron  

PubMed Central

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.

Zhuo, Jia L.; Li, Xiao C.

2013-01-01

30

Proximity fuze  

Microsoft Academic Search

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

1987-01-01

31

Proximity fuze  

Microsoft Academic Search

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

Thomas R

1989-01-01

32

Proximity fuze  

Microsoft Academic Search

A proximity fuze system is described. It 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

1989-01-01

33

Phosphorylation of Ser982 in the sodium bicarbonate cotransporter kNBC1 shifts the HCO3?: Na+ stoichiometry from 3:1 to 2:1 in murine proximal tubule cells  

PubMed Central

Adenosine 3?,5?-cyclic monophosphate (cAMP) modulates proximal tubule sodium and bicarbonate absorption by decreasing the rate of apical Na+-H+ exchange and basolateral sodium bicarbonate efflux, through activation of protein kinase A (PKA). The electrogenic sodium bicarbonate cotransporter kNBC1 mediates basolateral sodium and bicarbonate efflux in the proximal tubule by coupling the transport of 1 Na+ cation to that of 3 HCO3? anions. In this work we studied the effects of cAMP on the function of kNBC1 expressed heterologously in a proximal tubule cell line. A mouse renal proximal tubule cell line, deficient in electrogenic sodium bicarbonate cotransport function, was transfected with kNBC1. Cells were grown on a permeable support to confluence, mounted in an Ussing chamber and permeabilized apically with amphotericin B. Current through the cotransporter was isolated as the difference current due to the reversible inhibitor dinitrostilbene disulfonate. The HCO3?:Na+ stoichiometry of kNBC1 was calculated from its reversal potential by measuring the current-voltage relationships of the cotransporter at different Na+ concentration gradients. Addition of the potent cAMP agonsit 8-Br-cAMP caused the stoichiometry of kNBC1 to shift from 3 HCO3?: 1 Na+ to 2 HCO3?:1 Na+. Pretreatment of the cells with the PKA inhibitor H-89 abolished the effect of the agonist on the stoichiometry change. Replacing Ser982 at the C-terminus consensus PKA phosphorylation site with alanine resulted in a failure of PKA to phosphorylate the transporter and induce a stoichiometry shift. Our data indicate that cAMP modulates the stoichiometry of kNBC1 through activation of PKA. The change in stoichiometry from 3:1 to 2:1 is predicted to cause a shift in the direction of basolateral membrane sodium bicarbonate transport from efflux to influx. Ser982 in the C-terminus of kNBC1 is a target for PKA phosphorylation. This is the first example of modulation of the stoichiometry of a membrane transporter by phosphorylation.

Gross, E; Hawkins, K; Pushkin, A; Sassani, P; Dukkipati, R; Abuladze, N; Hopfer, U; Kurtz, I

2001-01-01

34

Proximity fuze  

DOEpatents

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.

1987-07-10

35

Proximity fuze  

DOEpatents

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) [Stockton, CA

1989-08-22

36

Clonal Analysis of Immortalized Renal Proximal Tubule Cells: Na +\\/Glucose Cotransport System Levels Are Maintained Despite a Decline in Transport Function  

Microsoft Academic Search

Primary rabbit kidney proximal tubule (RPT) cells (S.D. Chung et al., 1982, J. Cell Biol. 95, 118–126) were transfected with the vector pRSV-T, which contains SV40 early region genes. After the third passage (when normal cells had stopped dividing), individual colonies formed in cultures transfected with pRSV-T. Clonal isolates (RPT-I cells) could be obtained in a simple and reproducible manner.

Mary Taub; Ho Jae Han; Trivikram Rajkhowa; Cheryl Allen; Jun Hong Park

2002-01-01

37

Proximal Biceps Tendonitis  

MedlinePLUS

... arm for a few weeks. What Is Biceps Tendonitis? The biceps is the muscle in your upper ... with rest and medication. Signs of Proximal Biceps Tendonitis Proximal biceps tendonitis usually starts out slowly and ...

38

Magnetic Bridge Proximity Sensor.  

National Technical Information Service (NTIS)

A proximity sensor for indicating the spatial proximity of a ferrous object comprising a magnetic reluctance bridge formed from a plurality of high and low permeability sections and with a ring core flux gate magnetometer disposed therebetween to form the...

F. W. Heemstra

1982-01-01

39

Inhibitory effect of ETB receptor on Na+-K+ ATPase activity by extracellular Ca2+ entry and Ca2+ release from the endoplasmic reticulum in renal proximal tubule cells  

PubMed Central

The kidney is important in the long-term regulation of blood pressure and sodium homeostasis. Stimulation of ETB receptors in the kidney increases sodium excretion, in part, by decreasing sodium transport in the medullary thick ascending limb of Henle and in collecting duct. However, the role of ETB receptor on Na+–K+ ATPase activity in renal proximal tubule (RPT) cells is not well defined. The purpose of this study is to test the hypothesis that ETB receptor inhibits Na+–K+ ATPase activity in rat RPT cells, and investigate the mechanism(s) by which such an action is produced. In RPT cells from Wistar–Kyoto rats, stimulation of ETB receptors by the ETB receptor agonist, BQ3020, decreased Na+–K+ ATPase activity, determined by ATP hydrolysis (control=0.38±0.02, BQ3020=0.26±0.03, BQ788=0.40±0.06, BQ3020+BQ788=0.37±0.04, n=5, P<0.01). The ETB receptor-mediated inhibition of Na+–K+ ATPase activity was dependent on an increase in intracellular calcium, because this effect was abrogated by a chelator of intracellular-free calcium (BAPTA-AM; 5×10?3 m 15 min?1), Ca2+ channel blocker (10?6 m 15 min?1 nicardipine) and PI3 kinase inhibitor (10?7 m per wortmannin). An inositol 1,4,5-trisphosphate (IP3) receptor blocker (2-aminoethyl diphenyl borate; 10?4 m 15 min?1) also blocked the inhibitory effect of the ETB receptor on Na+–K+ ATPase activity (control=0.39±0.06, BQ3020=0.25±0.01, 2-APB=0.35±0.05, BQ3020+ 2-APB=0.35±0.06, n=4, P<0.01). The calcium channel agonist (BAY-K8644; 10?6 m 15 min?1) inhibited Na+–K+ ATPase activity, an effect that was blocked by a phosphatidylinositol-3 kinase inhibitor (10?7 m 15 min?1 wortmannin). In rat RPT cells, activation of the ETB receptor inhibits Na+–K+ ATPase activity by facilitating extracellular Ca2+ entry and Ca2+ release from endoplasmic reticulum.

Liu, Yan; Yang, Jian; Ren, Hongmei; He, Duofen; Pascua, Annabelle; Armando, M Ines; Yang, Chengming; Zhou, Lin; Felder, Robin A; Jose, Pedro A; Zeng, Chunyu

2010-01-01

40

Proximity and Localization  

Microsoft Academic Search

Torre A. and Rallet A. (2005) Proximity and localization, Regional Studies39, 47- 59. The objective of this paper is to pave the way for an analysis of the relations between proximity and localization of activities and people, two notions that are often mistaken for one another. Our method consists in exploiting the semantic wealth of the notion of proximity. We

Andre Torre; Alain Rallet

2005-01-01

41

Proximity of transmembrane segments M3 and M1 of the alpha subunit of Na+,K+-ATPase revealed by specific oxidative cleavage mediated by a complex of Cu2+ ions and 4,7-diphenyl-1,10-phenanthroline.  

PubMed

This paper describes a novel approach to specific oxidative cleavage of Na(+),K(+)-ATPase, mediated by Cu(2+) ions and a hydrophobic phenanthroline, 4,7-diphenyl-1,10-phenanthroline (DPP), in the presence of ascorbate and H(2)O(2). The cleavage produces two major fragments of the alpha subunit, with apparent molecular masses of 96.5 and 76 kDa, and N-termini near the cytoplasmic entrance of transmembrane segments M1 and M3, respectively, The kinetics indicate that both cleavages are mediated by a single Cu(2+)-DPP complex. We infer that M3 and M1 are in proximity near the cytoplasmic surface. The yields of 96.5 and 76 kDa fragments are not significantly affected by ligands that stabilize different E(1) and E(2) conformations. In E(2)(K) and E(2)P conformations, a minor 5.5 kDa fragment with its N-terminus in M10 is also observed. The 96.5 and 76 kDa fragments are indistinguishable from two fragments near M3 and M1 produced by Fe(2+)-catalyzed cleavage described previously [Goldshleger, R., and Karlish, S. J. D. (1999) J. Biol. Chem. 274, 16213-16221], whereas other Fe(2+)-catalyzed cleavage fragments in the cytoplasmic P and A domains are not observed with the Cu(2+)-DPP complex. These findings provide experimental support for the concept of two separate Fe(2+) sites. A homology model, with Na(+),K(+)-ATPase residues within transmembrane segments and connecting loops substituted into the crystal structure of Ca(2+)-ATPase, shows the proximity between the sequences HFIH in M3 and EVWK in M1, near the cytoplasmic surface. Thus, the model strongly supports the conclusions based on cleavages mediated by the Cu(2+)-DPP complex (or Fe(2+) at site 2). As a corollary, the cleavages provide evidence for similar packing of M1 and M3 of Na(+),K(+)-ATPase and Ca(2+)-ATPase. PMID:11601974

Tal, D M; Capasso, J M; Munson, K; Karlish, S J

2001-10-23

42

Two Headed Magnetic Proximity Sensor.  

National Technical Information Service (NTIS)

The present invention relates generally to magnetic proximity detectors, and more particularly to magnetic proximity switches utilizing a dc magnetic flux as the physical property to be detected. The magnetic proximity sensor detects the proximity of a la...

F. W. Heemstra

1982-01-01

43

Proximal femoral replacement.  

PubMed

Reconstruction of the proximal femur after extensive bone loss is clinically challenging. Options for reconstruction depend on the classification and extent of the proximal femoral defect. Although reconstitution of the native proximal femoral bone stock are the traditional goals of most revision techniques for the proximal femur, these techniques lose their effectiveness after numerous revisions due to the severe loss of a sufficient amount of structural bone needed to reconstruct the femur and abductor attachment. Consequently, the proximal femoral bone becomes fragile with extensive bone loss despite bone grafting. Techniques that use allograft-prosthetic composite and femoral megaprosthesis can successfully restore a patient's ambulatory ability despite the absence of significant portions of the proximal femur. PMID:12008848

Cheng, Edward Y; Thompson, Roby C

2002-04-01

44

Neurogenic regulation of proximal bicarbonate and chloride reabsorption.  

PubMed

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

1986-01-01

45

Proximal Hamstring Avulsion Injuries  

PubMed Central

Proximal hamstring avulsions from the ischium are becoming more frequently recognized, secondary to their disability when treated nonoperatively. The acute repair of these injuries is becoming prevalent given the improved outcomes reported in the literature. Anatomic studies have recently been conducted on the proximal hamstring origin; however, there are few reports on surgical techniques for repair in the setting of injury. The present article describes the technique for proximal hamstring avulsion repair, as performed by the senior author. More than 30 cases have been performed based on this technique, with excellent results.

Pombo, Mathew; Bradley, James P.

2009-01-01

46

Proximal Humeral Fractures: Nailing  

Microsoft Academic Search

Treating proximal humeral fractures surgically has always been a challenge for the orthopaedic trauma surgeon. The challenge\\u000a was and is due to numerous factors such as the specific anatomy of the proximal humerus, problems of an adequate approach\\u000a and exposure of the fracture and different fracture fragments, possible iatrogenic injuries to the rotator cuff on approach\\u000a and the detrimental effects

Johannes Maria Rueger; Andreas Rücker; Daniel Briem; Lars Grossterlinden; Wolfgang Linhart

2007-01-01

47

Proximal wrist extensor tendinopathy  

Microsoft Academic Search

Proximal wrist extensor tendinopathy, which is also known as tennis elbow, is pain at or just distal to the lateral humeral\\u000a epicondyle within the proximal wrist extensor tendon. It occurs commonly in certain athletes but can also occur in people\\u000a with jobs that require repetitive movements of the hand and upper limb. In most cases the tendon involved shows no

Joseph Ihm

2008-01-01

48

Regulation of phosphate transport in proximal tubules.  

PubMed

Homeostasis of inorganic phosphate (P(i)) is primarily an affair of the kidneys. Reabsorption of the bulk of filtered P(i) occurs along the renal proximal tubule and is initiated by apically localized Na(+)-dependent P(i) cotransporters. Tubular P(i) reabsorption and therefore renal excretion of P(i) is controlled by a number of hormones, including phosphatonins, and metabolic factors. In most cases, regulation of P(i) reabsorption is achieved by changing the apical abundance of Na(+)/Pi cotransporters. The regulatory mechanisms involve various signaling pathways and a number of proteins that interact with Na(+)/P(i) cotransporters. PMID:18758808

Biber, J; Hernando, N; Forster, I; Murer, H

2009-05-01

49

Capacitive proximity sensor  

DOEpatents

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)

1994-01-01

50

Capacitive proximity sensor  

DOEpatents

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.

1994-05-31

51

Visualizing Proximity Data  

Microsoft Academic Search

In this article, the authors explore the use of graph layout algorithms for visualizing proximity matrices such as those obtained in cultural domain analysis. Traditionally, multidimensional scaling has been used for this purpose. The authors compare the two approaches to identify conditions when each approach is effective. As might be expected, they find that multidimensional scaling shines when the data

Rich DeJordy; Stephen P. Borgatti; Chris Roussin; Daniel S. Halgin

2007-01-01

52

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.

1997-01-01

53

Proximate analysis of coal  

SciTech Connect

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)

2009-02-15

54

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, Zoltán

2007-03-01

55

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. Güler (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

2011-09-01

56

Polymer infrared proximity sensor  

Microsoft Academic Search

A proximity sensor that combines a polymer light-emitting diode and a polymer photodiode is presented. The operation wavelength is in the near infrared from 700 to 850 nm. The infrared emission is obtained by adding a color conversion film of polyvinylpyrrolidone polymer matrix blended with infrared dye 1,1-diethyl-2,2-dicarbocyanine iodide to a red polymer light-emitting diode. The photodetector relies on the

En-Chen Chen; Shin-Rong Tseng; Jia-Hong Ju; Chia-Ming Yang; Hsin-Fei Meng; Sheng-Fu Horng; Ching-Fong Shu

2008-01-01

57

Proximity in agreement errors  

Microsoft Academic Search

Across languages subject-verb agreement errors have been established when subjects are producing complex (NP PP) noun-phrases (see Bock, 1995, for an overview). Very recently, Haskell & MacDonalds (2002) proposed a locality-based principle, the principle of proximity, to explain a variety of agreement errors in production. They base they argument partly on preferences in verb number marking in sentences with disjunctive

Barbara Hemforth; Robert Schuman

58

Proximal tibiofibular dislocation  

PubMed Central

Proximal tibiofibular joint dislocation is an uncommon injury, which may be easily missed on plain radiography. If recognised, it can be treated in the emergency department, avoiding surgery and long term problems. The case is presented of a 22 year old male rugby player who was tackled from the left hand side while turning to the left. He heard a “pop” from his knee as he fell to the ground. Clinical examination revealed a prominence in the area of the fibular head. There was no evidence of peroneal nerve injury. Plain x rays confirmed a clinical suspicion for anterior dislocation of the proximal tibiofibular joint. Proximal tibiofibular joint dislocation typically occurs when the knee is slightly flexed and the foot is rotated and plantar flexed. Antero lateral dislocation is the most common pattern. Diagnosis is largely clinical, but the findings may be subtle. Plain films may not show any abnormality and computed tomography is the investigation of choice if there is clinical suspicion for the injury. The dislocation should be reduced in the emergency department, but controversy exists whether early mobilisation or casting is the most appropriate course of action.

Horan, J; Quin, G

2006-01-01

59

Proximal tibiofibular dislocation.  

PubMed

Proximal tibiofibular joint dislocation is an uncommon injury, which may be easily missed on plain radiography. If recognised, it can be treated in the emergency department, avoiding surgery and long term problems. The case is presented of a 22 year old male rugby player who was tackled from the left hand side while turning to the left. He heard a "pop" from his knee as he fell to the ground. Clinical examination revealed a prominence in the area of the fibular head. There was no evidence of peroneal nerve injury. Plain x rays confirmed a clinical suspicion for anterior dislocation of the proximal tibiofibular joint. Proximal tibiofibular joint dislocation typically occurs when the knee is slightly flexed and the foot is rotated and plantar flexed. Antero lateral dislocation is the most common pattern. Diagnosis is largely clinical, but the findings may be subtle. Plain films may not show any abnormality and computed tomography is the investigation of choice if there is clinical suspicion for the injury. The dislocation should be reduced in the emergency department, but controversy exists whether early mobilisation or casting is the most appropriate course of action. PMID:16627827

Horan, J; Quin, G

2006-05-01

60

Electrically driven optical proximity correction  

NASA Astrophysics Data System (ADS)

Existing optical proximity correction tools aim at minimizing edge placement errors (EPE) due to the optical and resist process by moving mask edges. However, in low-k1 lithography, especially at 45nm and beyond, printing perfect polygons is practically impossible to achieve in addition to incurring prohibitively high mask complexity and cost. Given the impossibility of perfect printing, we argue that aiming to reduce the error of electrical discrepancy between the ideal and the printed contours is a more reasonable strategy. In fact, we show that contours with non-minimal EPE may result in closer match to the desired electrical performance. Towards achieving this objective, we developed a new electrically driven OPC (ED-OPC) algorithm. The tool combines lithography simulation with an accurate contour-based model of shape electrical behavior to predict the on/off current through a transistor gate. The algorithm then guides edge movements to minimize the error in current, rather than in edge placement, between current values for printed and target shapes. The results on industrial 45nm SOI layouts using high-NA immersion lithography models show up to a 5% improvement in accuracy of timing over conventional OPC, while at the same time showing up to 50% reduction in mask complexity for gate regions. The results confirm that better timing accuracy can be achieved despite larger edge placement error.

Banerjee, Shayak; Elakkumanan, Praveen; Liebmann, Lars W.; Culp, James A.; Orshansky, Michael

2008-04-01

61

Chloride transport in human proximal colonic apical membrane vesicles.  

PubMed

The mechanism(s) of Cl- transport across the human colonic apical membranes are not well understood. Apical membrane vesicles (AMV) purified from organ donor proximal colonic mucosa and a rapid millipore filtration technique were utilized to study 36Cl- uptake into these vesicles. Outwardly directed OH- and HCO3- gradient stimulated 36Cl- uptake into these vesicles demonstrating a transient accumulation over equilibrium uptake. Voltage clamping the membrane potential of the vesicles or making them inside positive with K+/valinomycin failed to influence chloride uptake, indicating that the conductive Cl- uptake pathway is minimal in proximal colonic AMV. Anion exchange inhibitors, DIDS and SITS (1 mM) inhibited OH- and HCO3- stimulated 36Cl- uptake by approximately 60%. Furosemide also demonstrated a small but significant inhibition of chloride uptake. Amiloride, bumetanide and acetazolamide (1 mM) failed to inhibit 36Cl uptake. HCO3- and pH gradient stimulated 36Cl- uptake exhibited saturation kinetics with an apparent Km for chloride of 4.0 +/- 0.7 mM and Vmax of 17.8 +/- 3.9 nmol/mg per min. Bromide, chloride, nitrate and acetate (50 mM each) inhibited 5 mM 36Cl uptake. Inwardly directed gradients of Na+, K+, or Na+ and K+ did not stimulate 36Cl- uptake into these vesicles, indicating that uptake of Na+ and Cl- in human proximal colonic AMV does not involve Na-Cl or Na-K-2Cl cotransport. The above findings indicate that chloride transport in human proximal colonic AMV involves an electroneutral Cl-HCO3- (OH-) exchange process. In view of the previous demonstration of Na+-H+ antiporter in these vesicles, dual ion exchange mechanism of Na+-H+ and Cl-HCO3- in apical membrane domain of human colonocytes is postulated to be the primary mechanism for NaCl absorption in the human proximal colon. PMID:8634305

Mahajan, R J; Baldwin, M L; Harig, J M; Ramaswamy, K; Dudeja, P K

1996-04-01

62

Distributed Optoelectronic Proximity Sensor  

NASA Technical Reports Server (NTRS)

Optoelectronic proximity sensor comprises seven identical units functioning together to provide partially redundant data on spatial relationship between sensor and nearby diffusely reflecting surface. Provides data on distance, relative orientation, and curvature of surface. Sensor called "Hexeye" because its units exhibit hexagonal symmetry when viewed along optical axes and mounted together in hexagonal close packing. Because all six arrays of photodetectors in unit measure essentially identical distributions of light in operating mode, each provides redundant information averaged to increase accuracy or used to verify operation of others. Malfunctioning photodector identified, and output ignored or replaced by interpolated value. Developed for use in such robotic applications as noncontact probing or scanning of surfaces, localization and recognition of objects, and guiding "smart" robot hands in grasping objects.

Lee, Sukhan; Hahn, Hernsoo

1994-01-01

63

A General Proximity Privacy Principle  

Microsoft Academic Search

This work presents a systematic study of the problem of protecting general proximity privacy, with findings applicable to most existing data models. Our contributions are multi-folded: we highlighted and formulated proximity privacy breaches in a data-model-neutral manner; we proposed a new privacy principle (epsiv,delta)k-dissimilarity, with theoretically guaranteed protection against linking attacks in terms of both exact and proximate QI-SA associations;

Ting Wang; Shicong Meng; Bhuvan Bamba; Ling Liu; Calton Pu

2009-01-01

64

Proximity projection grating structured light illumination microscopy.  

PubMed

Structured illumination has been employed in fluorescence microscopy to extend its lateral resolution. It has been demonstrated that a factor of 2 improvement can be achieved. In this paper, we introduce a novel optical arrangement that can further improve the resolution. It makes use of a fine grating held in close proximity to the sample. The fringe pattern thus projected onto the sample contains grating vectors substantially higher than those that are possible with the conventional structured illumination setup. We will present experimental results to demonstrate the principle of the technique, and will show that, theoretically, it can achieve an imaging NA approaching 4. PMID:21124532

See, Chung W; Chuang, Chin-Jung; Liu, Shugang; Somekh, Michael G

2010-12-01

65

Metatarsalgia: proximal metatarsal osteotomies.  

PubMed

Metatarsalgia is a blanket term to describe pain in the forefoot that may have many different etiologies and contributory factors. A careful history, examination, and appropriate imaging are required to make an accurate diagnosis and treat the patient appropriately. Metatarsalgia is a common condition and is more common in women. Many nonsurgical treatments can be implemented as a first line but if these fail then surgery may be undertaken. There are several different lesser metatarsal osteotomies described with little published evidence to recommend one over another, leaving the decision as to which one to use largely to surgeon choice. The surgeon, however, must decide, by using a combination of clinical examination and imaging, whether the desired effect of the osteotomy is to shorten or elevate the metatarsal head or both. Whichever method is employed it is important to maintain or restore the metatarsal cascade to keep even pressure under the lesser metatarsal heads and prevent transfer lesions. Proximal osteotomies are more powerful than distal ones but often that can mean that they are more technically demanding. Many early descriptions of osteotomy techniques did not include any fixation but the results in terms of union and relief of symptoms as well as the prevention of transfer pain appear to be better with fixation. More research is required comparing the different osteotomy techniques to ascertain which can most reliably resolve patients’ symptoms with the lowest complication rate. PMID:22118232

Pearce, Christopher J; Calder, James D

2011-12-01

66

Optical Proximity Sensor Development Program.  

National Technical Information Service (NTIS)

The purpose of this program was to design and develop an Active Optical Proximity Sensor capable of providing a near surface proximity indication and detaonting signal. The sensor was to be designed as a plug-in module to the Impact Short Delay Fuze for u...

F. S. Gemmel

1973-01-01

67

Link Proximity Analysis - Clustering Websites by Examining Link Proximity  

Microsoft Academic Search

\\u000a This research-in-progress paper presents a new approach called Link Proximity Analysis (LPA) for identifying related web pages\\u000a based on link analysis. In contrast to current techniques, which ignore intra-page link analysis, the one put forth here examines\\u000a the relative positioning of links to each other within websites. The approach uses the fact that a clear correlation between\\u000a the proximity of

Bela Gipp; Adriana Taylor; Jöran Beel

2010-01-01

68

Aerodynamic characteristics in ground proximity  

NASA Technical Reports Server (NTRS)

Results from recent investigations in the Langley V/STOL tunnel of an externally blown flap and an upper surface blown flap configuration in ground proximity are presented. Comparisons of longitudinal aerodynamic characteristics indicate that in ground proximity, drag is reduced for both configurations, but changes in lift are configuration dependent. Steady state analyses of the landing approach indicate an increase in flight path angle for both configurations in ground proximity because of the drag reduction. Dynamic analyses with a fixed-base simulator indicate that the resultant flight path during landing approach is dependent on the initial flight path angle and the control technique used.

Thomas, J. L.; Hassell, J. L., Jr.; Nguyen, L. T.

1976-01-01

69

The abnormal proximal tibiofibular joint.  

PubMed

Abnormalities of the proximal tibiofibular joint are infrequently encountered. Mostly instability occurs as a result of trauma. Four types of instability are distinguished: subluxation, anterolateral, posteromedial and superior dislocation. Four radiological methods designed to visualize abnormalities of the proximal tibiofibular joint are discussed. Special notice is given to the clinical relevance of a new method. Instability was demonstrated in 19 patients; 16 of these were treated by an operation. History, data obtained by physical examination and ways of treatment are discussed. PMID:6703874

Veth, R P; Kingma, L M; Nielsen, H K

1984-01-01

70

Phorbol esters inhibit ammoniagenesis and gluconeogenesis in proximal tubular segments  

SciTech Connect

To characterize the regulation of ammoniagenesis and gluconeogenesis in renal proximal tubule, ammonia and glucose productions were measured in suspension of canine proximal tubular segments incubated with 10 mM L-glutamine. Productions were linear functions of time for 120 min and were decreased as extracellular pH was increased from 7.0 to 7.5. To ascertain whether activation of protein kinase c affects either process, the authors incubated segments with tumor-promoting phorbol esters, 12-O-tetradecanoylphorbol-13-acetate (TPA), or phorbol 12,13-dibutyrate, or with the inactive phorbol ester 4..cap alpha..-phorbol. Ammoniagenesis and gluconeogenesis were inhibited by incubation with 10/sup /minus/6/M of the two former compounds but not the latter compound. Phorbol ester-induced inhibition was observed under conditions such that extracellular (Na/sup +/) was greater than intracellular (Na/sup +/), but not when extracellular (Na/sup +/) equaled intracellular (Na/sup +/), and was not observed in the presence of amiloride. These findings are consistent with a role for protein kinase c in the control of ammoniagenesis and gluconeogenesis in proximal tubule. Such control could be mediated via stimulation of Na/sup 1/-H/sup +/ exchange.

Chobanian, M.C.; Hammerman, M.R.

1987-06-01

71

Scanner-dependent optical proximity effects  

NASA Astrophysics Data System (ADS)

Optical imaging of IC critical designs is impacted by optical proximity effects, OPEs, originating from finite numerical aperture of projection lenses used in modern projectors. The OPE's are caused by filtering of pattern diffraction orders falling outside of the lens band pass. Controlling OPEs is so critical to IC performance, that IC design community implemented optical proximity correction, OPC, modifying the IC mask patterns to provide wafer images matching the IC design intent. The mainstream OPC uses optical models representing fundamental imaging setup and it does not capture the impacts of engineering scanner tool constraints. The OPEs are impacted by scanner lens and illuminator signatures causing CD excursions large in comparison to the CD error budgets(1). The magnitude of the scanner impacts on OPEs necessitated new optical modeling paradigm involving imaging models imbedding scanner signatures representing population of scanners of a given type. These scanner-type based models represent quantum leap in accuracy of lithography simulation technology, resulting in OPE and OPC representing a broad range of realistic scanner characteristics(2). In this context, a relevant question is: to what degree, the signatures of individual scanners impact the accuracy of imaging models and OPE predictions? To answer this question, we analyzed optical proximity responses of hyper-NA scanners represented by their signatures. We first studied a set of OPEs impacted by the scanner-type signatures. We then generated a set of corresponding OPEs impacted by the signatures of individual scanners. We compared the two kinds of OPEs and highlighted the scanner-specific image formation responses.

Tyminski, Jacek K.; Matsuyama, Tomoyuki; Nakashima, Toshiharu; Inoue, Ryuichi

2009-03-01

72

Aldosterone Stimulates Activity and Surface Expression of NHE3 in Human Primary Proximal Tubule Epithelial Cells (RPTEC)  

Microsoft Academic Search

The steroid hormone aldosterone is a major regulator of extracellular volume and blood pressure. Aldosterone effectors are for example the epithelial Na+ channel (ENaC), the Na+-K+-ATPase and the proximal tubule Na+\\/H+ exchanger isoform 3 (NHE3). The aim of this study was to investigate whether aldosterone acts directly on proximal tubule cells to stimulate NHE3 and if so whether the EGF-receptor

Karina Drumm; Theresia R. Kress; Birgit Gassner; Alexander W. Krug; Michael Gekle

2006-01-01

73

Multiclass Proximal Support Vector Machines  

Microsoft Academic Search

Abstract. We propose an extension of proximal support vector machines (PSVM) to the multiclass case. Unlike the one-versus-rest approach that constructs the decision rule based on multiple binary classication tasks, the multiclass PSVM (MPSVM) considers all classes simultaneously and provides a unifying framework when there are either equal or unequal misclassication costs. The MPSVM is built in a regularization framework

Yongqiang Tang; Hao Helen Zhang

2006-01-01

74

Proximal humeral resection and reconstruction  

Microsoft Academic Search

Resection of the proximal humerus may be required for control of benign, primary malignant, or metastatic neoplasms. The defect created by such a resection may spare the shoulder cuff muscles and deltoid (Malawer type IA) or remove them (Malawer type IB). Reconstruction of these defects and restoration of some degree of shoulder function may be accomplished by a variety of

John M. Harrelson

1999-01-01

75

Driven shielding capacitive proximity sensor  

NASA Technical Reports Server (NTRS)

A capacitive proximity sensing element, backed by a reflector driven at the same voltage as and in phase with the sensor, is used to reflect the field lines away from a grounded robot arm towards an intruding object, thus dramatically increasing the sensor's range and sensitivity.

Vranish, John M. (Inventor); McConnell, Robert L. (Inventor)

2000-01-01

76

Proximity problems on moving points  

Microsoft Academic Search

A kinetic data structure for the maintenance of a multidimensional range search tree is introduced. This structure is used as a building block to obtain kinetic data structures for two classical geometric proximity problems in arbitrary dimensions: the first structure maintains the closest pair of a set of continuously moving points, and is provably efficient. The second structure maintains a

Julien Basch; Leonidas J. Guibas; Li Zhang

1997-01-01

77

Geographic Proximity and Enrollment Competition.  

ERIC Educational Resources Information Center

The use of a measure of geographic proximity to help explain enrollment competition among postsecondary institutions was investigated. The measure, the number of miles between institutions, was obtained by determining the longitude and latitude coordinates for about 99% of the schools in the Higher Education General Information System universe.…

Zammuto, Raymond F.

78

MODELING PROXIMAL TUBULE CELL HOMEOSTASIS: TRACKING CHANGES IN LUMINAL FLOW  

PubMed Central

During normal kidney function, there are are routinely wide swings in proximal tubule fluid flow and proportional changes in Na+ reabsorption across tubule epithelial cells. This "glomerulotubular balance" occurs in the absence of any substantial change in cell volume, and is thus a challenge to coordinate luminal membrane solute entry with peritubular membrane solute exit. In this work, linear optimal control theory is applied to generate a configuration of regulated transporters that could achieve this result. A previously developed model of rat proximal tubule epithelium is linearized about a physiologic reference condition; the approximate linear system is recast as a dynamical system; and a Riccati equation is solved to yield the optimal linear feedback that stabilizes Na+ flux, cell volume, and cell pH. The first observation is that optimal feedback control is largely consigned to three physiologic variables, cell volume, cell electrical potential, and lateral intercellular hydrostatic pressure. Parameter modulation by cell volume stabilizes cell volume; parameter modulation by electrical potential or interspace pressure act to stabilize Na+ flux and cell pH. This feedback control is utilized in a tracking problem, in which reabsorptive Na+ flux varies over a factor of two. The resulting control parameters consist of two terms, an autonomous term and a feedback term, and both terms include transporters on both luminal and peritubular cell membranes. Overall, the increase in Na+ flux is achieved with upregulation of luminal Na+/H+ exchange and Na+-glucose cotransport, with increased peritubular Na+?3HCO3? and K+ ? Cl? cotransport, and with increased Na+, K+-ATPase activity. The configuration of activated transporters emerges as testable hypothesis of the molecular basis for glomerulotubular balance. It is suggested that the autonomous control component at each cell membrane could represent the cytoskeletal effects of luminal flow.

Weinstein, Alan M.; Sontag, Eduardo D.

2009-01-01

79

Modeling proximal tubule cell homeostasis: tracking changes in luminal flow.  

PubMed

During normal kidney function, there are routinely wide swings in proximal tubule fluid flow and proportional changes in Na(+) reabsorption across tubule epithelial cells. This "glomerulotubular balance" occurs in the absence of any substantial change in cell volume, and is thus a challenge to coordinate luminal membrane solute entry with peritubular membrane solute exit. In this work, linear optimal control theory is applied to generate a configuration of regulated transporters that could achieve this result. A previously developed model of rat proximal tubule epithelium is linearized about a physiologic reference condition; the approximate linear system is recast as a dynamical system; and a Riccati equation is solved to yield the optimal linear feedback that stabilizes Na(+) flux, cell volume, and cell pH. The first observation is that optimal feedback control is largely consigned to three physiologic variables, cell volume, cell electrical potential, and lateral intercellular hydrostatic pressure. Parameter modulation by cell volume stabilizes cell volume; parameter modulation by electrical potential or interspace pressure act to stabilize Na(+) flux and cell pH. This feedback control is utilized in a tracking problem, in which reabsorptive Na(+) flux varies over a factor of two, in order to represent a substantial excursion of glomerulotubular balance. The resulting control parameters consist of two terms, an autonomous term and a feedback term, and both terms include transporters on both luminal and peritubular cell membranes. Overall, the increase in Na(+) flux is achieved with upregulation of luminal Na(+)/H(+) exchange and Na(+)-glucose cotransport, with increased peritubular Na(+)-3HCO(3)(-) and K(+)-Cl(-) cotransport, and with increased Na(+), K(+)-ATPase activity. The configuration of activated transporters emerges as a testable hypothesis of the molecular basis for glomerulotubular balance. It is suggested that the autonomous control component at each cell membrane could represent the cytoskeletal effects of luminal flow. PMID:19280266

Weinstein, Alan M; Sontag, Eduardo D

2009-08-01

80

Amino acid transport in the renal proximal tubule  

Microsoft Academic Search

Summary.   In the kidney the proximal tubule is responsible for the uptake of amino acids. This occurs via a variety of functionally\\u000a and structurally different amino acid transporters located in the luminal and basolateral membrane. Some of these transporters\\u000a show an ion-dependence (e.g. Na+, Cl? and K+) or use an H+-gradient to drive transport. Only a few amino acid transporters

T. Gonska; J. R. Hirsch; E. Schlatter

2000-01-01

81

Intramedullary Chondrosarcoma of Proximal Humerus  

PubMed Central

Primary chondrosarcoma is the third most frequent primary malignancy of bone after myeloma and osteosarcoma. It is ranging from slow growing nonmetastasising lesions to highly aggressive lesions. We report a case of primary intramedullary chondrosarcoma of proximal humerus. A 60-year-old female presented with pain and hard swelling involving the left arm for 5 months. Radiograph showed a lucent expansile intramedullary lesion with matrix calcification and associated soft tissue mass. CT confirmed the finding. MRI showed a lobulated lesion which is hyperintense on T2WI with low signal fibrous septae. Increased tracer uptake was seen on bone scan. Histopathology confirmed the radiology diagnosis. The patient underwent wide resection and endoprosthetic reconstruction of proximal humerus.

Yadav, Pratiksha; Thakkar, Dolly; Thind, S. S.

2012-01-01

82

Plating in Proximal Humeral Fractures  

Microsoft Academic Search

Improved imaging, updated knowledge regarding humeral head perfusion and adapted fixation techniques with implants having\\u000a better purchase also in osteopenic bone, have influenced the treatment of proximal humeral fractures in recent years. Demographic\\u000a evolution and a more active population even among the older age groups will increase the incidence of this fracture, which\\u000a is already the third most frequent fracture

Reto Babst; Felix Brunner

2007-01-01

83

Proximal Humerus Reconstructions for Tumors  

PubMed Central

The optimal method for reconstructing the proximal humerus in patients with tumors is controversial. To determine functional outcomes and complication rates after different types of reconstructions, we reviewed a consecutive series of 49 patients who underwent proximal humerus resection and osteoarticular allograft (17 patients), allograft-prosthetic composite (16), or endoprosthetic (16) reconstruction. Operative indications included primary malignancies (24 patients), metastatic disease (19), and benign aggressive disease (six). Implant revision was more common after osteoarticular reconstruction (five of 17) than after allograft-prosthetic composite (one of 16) or endoprosthetic (zero of 16) reconstructions. At a minimum followup of 24 months (median, 98 months; range, 24–214 months) in surviving patients, Musculoskeletal Tumor Society functional scores averaged 79% for the allograft-prosthetic composite, 71% for the osteoarticular allograft, and 69% for the endoprosthetic reconstruction cohorts. Shoulder instability was associated with abductor mechanism compromise and was more common after endoprosthetic reconstruction. Allograft fractures occurred in 53% of patients receiving osteoarticular allografts. We recommend allograft-prosthetic composite reconstruction for younger patients with primary tumors of bone and endoprosthetic reconstruction for older patients with metastatic disease. Because of the unacceptable complication rate, we do not recommend osteoarticular allograft reconstruction for routine use in the proximal humerus. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Adams, Sheila C.; Pitcher, J. David; Malinin, Theodore I.; Temple, H. Thomas

2008-01-01

84

Proximity operations in space station environment  

NASA Technical Reports Server (NTRS)

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.

Rhodes, Brandt

1990-01-01

85

Proximal muscle atrophy in adult celiac disease  

Microsoft Academic Search

The finding of 2 patients with adult celiac disease and proximal muscle atrophy in whom malabsorption was not at first considered suggests that either malabsorption or adult celiac disease itself should be considered among the possible causes of proximal muscle atrophy. In proximal muscle atrophy of unknown cause, malabsorption should be routinely ruled out.

William Harvey Hall

1968-01-01

86

The HTV Proximity Communication System  

NASA Astrophysics Data System (ADS)

National Space Development Agency of Japan (NASDA) is developing the H-II Transfer Vehicle (HTV) as an unmanned logistic support vehicle for the International Space Station (ISS). The HTV, which is launched by the H-IIA rocket, transports both pressurized and un-pressurized cargoes to the ISS, reloads disposal items from the ISS and performs destructive reentry over ocean area. NASDA plans the first flight of HTV in 2005 for demonstration. The HTV will contribute the ISS assembly and logistic re-supply operations with international commonality. For unmanned vehicle operation, communication link is critical with commanding and control, especially in proximity region to the ISS. As for the HTV operation, NASDA is developing dedicated communication system installed on the Japanese Experiment Module (JEM) of the ISS, which is called the Proximity Communication System (PROX). The HTV receives commands and transmits telemetry data through the PROX in its proximity operation to the ISS. To achieve this, the PROX can communicate with the HTV on its nominal trajectory within 23km of the ISS. Especially within 3km of the ISS, the PROX has capability to perform omni-directional communication to the HTV. The PROX also has GPS receiver and send GPS data to the HTV to support the HTV navigation for relative GPS navigation used in "far" range (500m away from the ISS). In addition to the above fundamental functions, the PROX has a capability of range and range-rate measurement between the ISS and the HTV by the pseudo noise (PN) code epoch and the Doppler shift frequency. This provides a reference data independent of "main" navigation methods (rendezvous sensor navigation or GPS navigation) of the HTV. The PROX also assists the ISS crew with its commanding device, called the Hardware Command Panel (HCP), to issue time-dependent safety-related critical commands for HTV berthing/un-berthing operation. When a failure occurs somewhere on "communication path" from the PROX Base Band Processor (BBP) to the HTV Guidance and Control Computer (GCC) including data handling and communication equipments, the PROX detects it by monitoring interruption of the "heartbeat" signal and conducts automatic redundancy switching of all the equipments on that "communication path" including those of the HTV. This paper describes the PROX functions such as communication, data handling and GPS navigation and some unique functions for the HTV proximity operation to the ISS.

Harada, Motoyuki; Takahashi, Tetsuo; Tanaka, Tetsuo

2002-01-01

87

Proximal bodies in hypersonic flow  

NASA Astrophysics Data System (ADS)

Hypersonic flows involving two or more bodies travelling in close proximity to one another are encountered in several important situations. The present work seeks to explore one aspect of the resulting flow problem by investigating the forces experienced by a secondary body when it is within the domain of influence of a primary body travelling at hypersonic speeds.An analytical methodology based on the blast wave analogy is developed and used to predict the secondary force coefficients for simple geometries in both two and three dimensions. When the secondary body is entirely inside the primary shocked region, the nature of the lateral force coefficient is found to depend strongly on the relative size of the two bodies. For two spheres, the methodology predicts that the secondary body will experience an exclusively attractive lateral force if the secondary diameter is larger than one-sixth of the primary diameter. The analytical results are compared with those from numerical simulations and reasonable agreement is observed if an appropriate normalization for the relative lateral displacement of the two bodies is used.Results from a series of experiments in the T5 hypervelocity shock tunnel are also presented and compared with perfect-gas numerical simulations, with good agreement. A new force-measurement technique for short-duration hypersonic facilities, enabling the experimental simulation of the proximal bodies problem, is described. This technique provides two independent means of measurement, and the agreement observed between the two gives a further degree of confidence in the results obtained.

Laurence, Stuart J.; Deiterding, R.; Hornung, G.

88

Ash Aggregates in Proximal Settings  

NASA Astrophysics Data System (ADS)

Ash aggregates are thought to have formed within and been deposited by the eruption column and plume and dilute density currents and their associated ash clouds. Moist, turbulent ash clouds are considered critical to ash aggregate formation by facilitating both collision and adhesion of particles. Consequently, they are most commonly found in distal deposits. Proximal deposits containing ash aggregates are less commonly observed but do occur. Here we describe two occurrences of vent proximal ash aggregate-rich deposits; the first within a kimberlite pipe where coated ash pellets and accretionary lapilli are found within the intra-vent sequence; and the second in a glaciovolcanic setting where cored pellets (armoured lapilli) occur within <1 km of the vent. The deposits within the A418 pipe, Diavik Diamond Mine, Canada, are the residual deposits within the conduit and vent of the volcano and are characterised by an abundance of ash aggregates. Coated ash pellets are dominant but are followed in abundance by ash pellets, accretionary lapilli and rare cored pellets. The coated ash pellets typically range from 1 - 5 mm in diameter and have core to rim ratios of approximately 10:1. The formation and preservation of these aggregates elucidates the style and nature of the explosive phase of kimberlite eruption at A418 (and other pipes?). First, these pyroclasts dictate the intensity of the kimberlite eruption; it must be energetic enough to cause intense fragmentation of the kimberlite to produce a substantial volume of very fine ash (<62 ?m). Secondly, the ash aggregates indicate the involvement of moisture coupled with the presence of dilute expanded eruption clouds. The structure and distribution of these deposits throughout the kimberlite conduit demand that aggregation and deposition operate entirely within the confines of the vent; this indicates that aggregation is a rapid process. Ash aggregates within glaciovolcanic sequences are also rarely documented. The early pyroclastic phase of the formation of Kima'Kho, a tuya in northern B.C., Canada produced a subaqueous pyroclastic cone which became emergent during the latter stages of formation. Armoured lapilli are pervasive within the emergent upper third of the sequence. No other types of ash aggregates have been observed. Petrographic and textural analysis of the armoured lapilli shows them to comprise a central 2-30 mm-sized, juvenile, vesiculated pyroclast, concentrically coated by mm-scale layers of 10-250 ?m sized ash particles. At Kima'Kho, the armoured lapilli are shown to be a direct indicator of fallout from a sustained plume attended by concomitant production of pyroclastic density currents. The size and internal structure of the armoured lapilli provide constraints on the nature of the initial explosive phase of eruption at Kima'Kho. Their proximity to the vent also indicates rapid aggregation within the eruption plume. Within both sequences rapid aggregation of ash particles occurred in proximity to the vent. However, the conditions were substantially different leading to the production of armoured lapilli (no accretionary lapilli) at Kima'Kho and diverse ash aggregates but no armoured lapilli at A418. Here we investigate vent-proximal ash aggregation and the specific conditions which lead to the formation of coated ash pellets and armoured lapilli.

Porritt, L. A.; Russell, K.

2012-12-01

89

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,..., (H-PPA) 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 H-PPA 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

2010-09-01

90

Deformed proximity potential for heavy ion reactions  

SciTech Connect

The proximity potential is discussed for the inelastic scattering of a spherical nucleus on a deformed nucleus or the mutual interaction of two deformed nuclei. It is shown that the proximity potential is, in general, geometrically more correct than the usual centerline prescription used in inelastic scattering analyses. For the cases where the proximity potential is inadequate a folding model approach is advocated. Techniques to facilitate the coupled channels analysis are presented. 11 refs., 6 figs.

Baltz, A.J.

1989-09-01

91

Recurrent dislocation of the proximal tibiofibular joint.  

PubMed

Recurrent dislocation of the proximal tibiofibular joint is a rare injury. This report presents a case of bilateral recurrent dislocations of the proximal tibiofibular joint in a jet skier that responded to physical therapy and activity modification. A review of the literature is provided, with attention to the mechanism of injury and other treatment options--including arthrodesis and resection of the proximal fibula. This diagnosis should be considered in jet skiers with lateral-sided knee pain. PMID:1749660

Halbrecht, J L; Jackson, D W

1991-11-01

92

Claudin-2-deficient mice are defective in the leaky and cation-selective paracellular permeability properties of renal proximal tubules.  

PubMed

Claudin-2 is highly expressed in tight junctions of mouse renal proximal tubules, which possess a leaky epithelium whose unique permeability properties underlie their high rate of NaCl reabsorption. To investigate the role of claudin-2 in paracellular NaCl transport in this nephron segment, we generated knockout mice lacking claudin-2 (Cldn2(-/-)). The Cldn2(-/-) mice displayed normal appearance, activity, growth, and behavior. Light microscopy revealed no gross histological abnormalities in the Cldn2(-/-) kidney. Ultrathin section and freeze-fracture replica electron microscopy revealed that, similar to those of wild types, the proximal tubules of Cldn2(-/-) mice were characterized by poorly developed tight junctions with one or two continuous tight junction strands. In contrast, studies in isolated, perfused S2 segments of proximal tubules showed that net transepithelial reabsorption of Na(+), Cl(-), and water was significantly decreased in Cldn2(-/-) mice and that there was an increase in paracellular shunt resistance without affecting the apical or basolateral membrane resistances. Moreover, deletion of claudin-2 caused a loss of cation (Na(+)) selectivity and therefore relative anion (Cl(-)) selectivity in the proximal tubule paracellular pathway. With free access to water and food, fractional Na(+) and Cl(-) excretions in Cldn2(-/-) mice were similar to those in wild types, but both were greater in Cldn2(-/-) mice after i.v. administration of 2% NaCl. We conclude that claudin-2 constitutes leaky and cation (Na(+))-selective paracellular channels within tight junctions of mouse proximal tubules. PMID:20385797

Muto, Shigeaki; Hata, Masaki; Taniguchi, Junichi; Tsuruoka, Shuichi; Moriwaki, Kazumasa; Saitou, Mitinori; Furuse, Kyoko; Sasaki, Hiroyuki; Fujimura, Akio; Imai, Masashi; Kusano, Eiji; Tsukita, Shoichiro; Furuse, Mikio

2010-04-27

93

Second metatarsal stress fracture in sport: comparative risk factors between proximal and non-proximal locations  

PubMed Central

Background Stress fractures of the second metatarsal are common injuries in athletes and military recruits. There are two distinct areas in the second metatarsal where stress fractures develop: one proximal (at the base) and the other non?proximal (distal). Diagnosis can be difficult, and there is a difference in prognosis and treatment of the two types of stress fracture. Therefore differentiation of fracture location is warranted. Differences in risk factors and clinical outcomes between proximal and non?proximal stress fractures have not been studied. Objective To determine whether different risk factors and/or clinical outcomes associated with proximal and non?proximal stress fractures of the second metatarsal exist. Methods Patients diagnosed with proximal stress fractures of the second metatarsal were included in the study. Retrospectively, an age?matched control group with a non?proximal stress fracture was selected for comparison. Statistical analysis involved bivariate comparisons of demographic variables and clinical measurement between the two groups. Results Patients with proximal stress fractures were more likely to be chronically affected, usually exhibited an Achilles contracture, showed differences in length of first compared with second metatarsal, were more likely to experience multiple stress fractures, and exhibited low bone mass. In addition, a high degree of training slightly increased the risk of a non?proximal fracture, whereas low training volume was associated with a proximal stress fracture. Conclusion The signs, symptoms and clinical findings associated with proximal metatarsal stress fractures are different from those of non?proximal stress fractures.

Chuckpaiwong, Bavornrit; Cook, Chad; Pietrobon, Ricado; Nunley, James A

2007-01-01

94

Range gated strip proximity sensor  

DOEpatents

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. 6 figs.

McEwan, T.E.

1996-12-03

95

Range gated strip proximity sensor  

DOEpatents

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)

1996-01-01

96

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

2004-09-01

97

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 initial…

Chan, Selena

2013-01-01

98

Implications of Proximity Effects for Analog Design  

Microsoft Academic Search

This paper addresses two significant proximity effects, well proximity and STI stress, as they relate to analog circuit design. Device performance is impacted by layout features located near, but not part of the device. This adds new complexities to analog design. In either case, bias points can shift by 20-30%, causing potentially catastrophic failures in circuits. We show, for the

P. G. Drennan; M. L. Kniffin; D. R. Locascio

2006-01-01

99

Ensemble: cooperative proximity-based authentication  

Microsoft Academic Search

Ensemble is a system that uses a collection of trusted personal devices to provide proximity-based authentication in pervasive environments. Users are able to securely pair their personal devices with previously unknown devices by simply placing them close to each other (e.g., users can pair their phones by just bringing them into proximity). Ensemble leverages a user's growing collection of trusted

Andre Kalamandeen; Adin Scannell; Eyal de Lara; Anmol Sheth; Anthony LaMarca

2010-01-01

100

Grouping by proximity in haptic contour detection.  

PubMed

We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots), relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection. PMID:23762364

Overvliet, Krista E; Krampe, Ralf Th; Wagemans, Johan

2013-01-01

101

[Robot-assisted coelioscopic proximal tubal reanastomosis].  

PubMed

We report two cases of robot-assisted coelioscopic proximal tubal reanastomosis after proximal tubal ligature. Patients were aged 43 and 34 years respectively and had previously undergone proximal tubal ligation by coagulation section at 37 years of age for the first patient, and by Filshie clip at 24 years for the second one. Both had regular menstrual cycles and their ovarian reserve was good. Their partners were presenting with normal sperm criteria. Proximal tubal reanastomosis was carried out in September 2010 by robotic coelioscopy with five extramucous vicryl 5-0 stitches on each tube and positive blue testing. Total durations of the interventions were 200 and 220minutes respectively. Postoperative outcomes were simple and patients had spontaneous pregnancy at 4 and 2.5 months respectively. Both pregnancies show normal progress currently. This is a contribution to literature data meant to determine the role of robotics in proximal tubal reanastomosis. PMID:22521989

Carbonnel, M; Roulot, A; Fay, S; Ayoubi, J-M

2013-01-01

102

Ties in proximity and clustering compounds.  

PubMed

Hierarchical clustering algorithms such as Wards or complete-link are commonly used in compound selection and diversity analysis. Many such applications utilize binary representations of chemical structures, such as MACCS keys or Daylight fingerprints, and dissimilarity measures, such as the Euclidean or the Soergel measure. However, hierarchical clustering algorithms can generate ambiguous results owing to what is known in the cluster analysis literature as the ties in proximity problem, i.e., compounds or clusters of compounds that are equidistant from a compound or cluster in a given collection. Ambiguous ties can occur when clustering only a few hundred compounds, and the larger the number of compounds to be clustered, the greater the chance for significant ambiguity. Namely, as the number of "ties in proximity" increases relative to the total number of proximities, the possibility of ambiguity also increases. To ensure that there are no ambiguous ties, we show by a probabilistic argument that the number of compounds needs to be less than 2(n 1/4), where n is the total number of proximities, and the measure used to generate the proximities creates a uniform distribution without statistically preferred values. The common measures do not produce uniformly distributed proximities, but rather statistically preferred values that tend to increase the number of ties in proximity. Hence, the number of possible proximities and the distribution of statistically preferred values of a similarity measure, given a bit vector representation of a specific length, are directly related to the number of ties in proximities for a given data set. We explore the ties in proximity problem, using a number of chemical collections with varying degrees of diversity, given several common similarity measures and clustering algorithms. Our results are consistent with our probabilistic argument and show that this problem is significant for relatively small compound sets. PMID:11206366

MacCuish, J; Nicolaou, C; MacCuish, N E

2001-01-01

103

Rheogenic sodium-bicarbonate cotransport in the peritubular cell membrane of rat renal proximal tubule  

Microsoft Academic Search

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. Frömter

1985-01-01

104

Proximal bodies in hypersonic flow  

NASA Astrophysics Data System (ADS)

The problem of proximal bodies in hypersonic flow is encountered in several important situations, both natural and man-made. The present work seeks to investigate one aspect of this problem by exploring the forces experienced by a secondary body when some part of it is within the shocked region created by a primary body travelling at hypersonic speeds. An analytical methodology based on the blast wave analogy is developed and used to predict the secondary force coefficients for simple geometries in both two and three dimensions. When the secondary body is entirely inside the primary shocked region, the nature of the lateral coefficient is found to depend strongly on the relative size of the two bodies. For two spheres, the methodology predicts that the secondary body will experience an exclusively attractive lateral force if the secondary diameter is larger then one-sixth the primary diameter. The analytical results are compared with numerical simulations carried out using the AMROC software and good agreement is obtained if an appropriate normalization for the lateral displacement is used. Results from a series of experiments in the T5 hypervelocity shock tunnel are also presented and compared with perfect-gas numerical simulations, again with good agreement. In order to model this situation experimentally, a new force-measurement technique for short-duration hypersonic facilities has been developed, and results from the validation experiments are included. Finally, the analytical methodology is used to model two physical situations. First, the entry of a binary asteroid system into the Earth's atmosphere is simulated. Second, a model for a fragmenting meteoroid in a planetary atmosphere is developed, and simulations are carried out to determine whether the secondary scatter patterns in the Sikhote-Alin crater field may be attributed to aerodynamic interactions between fragments rather than to secondary fragmentation. It is found that while aerodynamic interactions lead to increased secondary crater grouping, these groups do not exhibit the typically elliptical shape that we would expect secondary fragmentation to produce.

Laurence, Stuart J.

105

Bidirectional active transport of thiosulfate in the proximal convolution of the rat kidney  

Microsoft Academic Search

Using the standing droplet method in the late proximal convolution and simultaneous microperfusion of the peritubular capillaries, the zero net flux transtubular concentration difference of thiosulfate at 45 s was determined, the latter being taken as a measure of active thiosulfate transport. Under control conditions, in the presence of Na+, near zero ?c values were observed. When 1 mmol\\/l carinamide

K. J. Ullrich; G. Rumrich; S. Klöss

1980-01-01

106

Proximal tubular cell electrolytes during volume expansion in the rat.  

PubMed Central

1. Proximal tubular intracellular elements were measured by electron microprobe X-ray analysis (a) in rats volume-expanded with albumin-saline in which peritubular oncotic pressure remained normal and (b) in rats in which the renal artery was snared before volume expansion (the early snare model). Glomerular filtration rate and urine Na+ excretion were measured in addition to intracellular Rb+ following a 30 s infusion of RbCl as a marker for K+ transport. 2. In albumin-saline volume-expanded rats, intracellular levels of Na+ ([Na+]i) at 21.5 +/- 0.6 mmol (kg wet wt)-1, Cl- ([Cl-]i) at 18.0 +/- 0.4 mmol (kg wet wt)-1 and Rb+ ([Rb+]i) at 9.4 +/- 0.4 mmol (kg wet wt)-1 were significantly higher (P < 0.0001) than the levels in non-expanded rats ([Na+]i, [Cl-]i and [Rb+]i at 17.7 +/- 0.4, 14.6 +/- 0.3 and 4.7 +/- 0.4 mmol (kg wet wt)-1, respectively; means +/- S.E.M.). The data are consistent with Na+ pump inhibition in the proximal tubule, although this cannot be directly derived from intracellular element measurements. 3. In an early snare model of volume expansion, [Na+]i, intracellular K+ ([K+]i) and [Rb+]i remained unchanged (16.1 +/- 0.4, 131.0 +/- 2.0 and 5.2 +/- 0.3 mmol (kg wet wt)-1, respectively) compared to non-expanded snared kidneys (15.9 +/- 0.6, 131.3 +/- 1.8 and 4.8 +/- 0.3 mmol (kg wet wt)-1, respectively). [Cl-]i at 18.3 +/- 0.5 mmol (kg wet wt)-1 increased (P < 0.0008) compared to controls at 15.8 +/- 0.5 mmol (kg wet wt)-1. Thus, in these rats, evidence for an inhibition of the Na+ pump was no longer observed. This points to a major intrinsic mechanism within the kidney for mediating natriuresis, since circulating factors were identical to those in the unsnared kidney, where significant natriuresis occurred.

Reddy, S; Gyory, A Z; Bostrom, T; Dyne, M; Salipan-Moore, N; Field, M J; Pollock, C A; Cockayne, D J

1994-01-01

107

Sodium Flux in Necturus Proximal Tubule under Voltage Clamp  

PubMed Central

Na transport and electrical properties of Necturus renal proximal tubules were analyzed, in vivo, by a voltage clamp method which utilizes an axial electrode in the tubule lumen for passage of current and simultaneous determination of net fluid (or Na) flux by the split droplet method. When the average spontaneous transepithelial potential difference of –8 mv (lumen negative) was reduced to zero by current passage, net Na flux doubled from a mean of 107 to 227 pmoles/cm2 per sec. The relationship between flux and potential over the range –25 to +10 mv was nonlinear, with flux equilibrium at –15 mv and droplet expansion at more negative values. Calculated Na permeability at flux equilibrium was 7.0 x 10–6 cm/sec. Voltage transients, similar to those caused by intraepithelial unstirred layers, were observed at the end of clamping periods. Tubular electrical resistance measured by brief square or triangle wave pulses (<100 msec) averaged 43 ohm cm2. The epithelial current-voltage relationship was linear over the range –100 to +100 mv, but displayed marked hysteresis during low frequency (<0.04 Hz) triangle wave clamps. The low transepithelial resistance and large opposing unidirectional ion fluxes suggest that passive ionic movements occur across extracellular shunt pathways, while the voltage transients and current-voltage hysteresis are consistent with the development of a local osmotic gradient within epithelium.

Spring, Kenneth R.; Paganelli, Charles V.

1972-01-01

108

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.

2012-05-15

109

Proximal tibiofibular subluxation relationship to lateral knee pain: a review of proximal tibiofibular joint pathologies.  

PubMed

Proximal tibiofibular subluxation is the symptomatic hypermobility of the proximal tibiofibular joint. Pain along the lateral aspect of the knee must be carefully evaluated as the anatomy and biomechanics of this region are very complex. Anatomical variants of the proximal tibiofibular joint may be key to understanding the pathomechanics and, thus, treatment of this joint. The "horizontal" proximal tibiofibular joint has a higher degree of mobility, while the "oblique" joint is relatively immobile to rotational forces on the fibula. Increased fibular external rotation will result in injury to the anterior capsule and ligaments of the proximal tibiofibular joint causing common complaints of "popping" and lateral knee pain. Treatment of proximal tibiofibular subluxation will involve modifications of a patient's activity level and training programs, utilization of a supportive strap, lower leg strengthening, and modifications in the lower kinetic chain biomechanics. PMID:7787848

Semonian, R H; Denlinger, P M; Duggan, R J

1995-05-01

110

Luminal secretion of ammonia in the mouse proximal tubule perfused in vitro.  

PubMed Central

A major portion of the total ammonia (tNH3 = NH3 + NH+4) produced by the isolated perfused mouse proximal tubule is secreted into the luminal fluid. To assess the role of Na+-H+ exchange in net tNH3 secretion, rates of net tNH3 secretion and tNH3 production were measured in proximal tubule segments perfused with control pH 7.4 Krebs-Ringer bicarbonate (KRB) buffer or with modified KRB buffers containing 10 mM sodium and 0.1 mM amiloride. Net tNH3 secretion was inhibited by 90% in proximal tubule segments perfused with the pH 7.4 modified KRB buffer while tNH3 production remained unaffected. The inhibition of net tNH3 secretion by perfusion with the modified KRB buffer was only partially reversed by acidifying the modified KRB luminal perfusate from 7.4 to as low as 6.2. These data indicate that the Na+-H+ exchanger facilitates a major portion of net tNH3 secretion by the proximal tubule and that luminal acidification may play only a partial role in the mechanism by which the Na+-H+ exchanger mediates net tNH3 secretion.

Nagami, G T

1988-01-01

111

Approaches to Proximal Tibial Bone Harvest Techniques  

PubMed Central

ABSTRACT Objectives The iliac crest is the standard site for harvesting bone; however, this procedure may require another specialist and a general anaesthetic. The proximal tibial bone harvest has gained popularity for harvesting autogenous bone. An analysis of the clinical literature regarding the various regions for harvesting bone demonstrates that the use of the proximal tibia led to shorter hospital stays, lower morbidity rates, and a shorter learning curve for the surgeon. The purpose of this study was to analyze the clinical anatomy of a proximal tibial bone harvest graft to provide the anatomical architecture supporting a safe procedure. Materials and Methods Dissection of 58 lower limbs from embalmed cadavers was conducted to determine the anatomy of a proximal tibial bone harvest (PTBH). Results Dissection revealed that the medial approach has fewer clinically relevant neurovascular structures in harms way, and a larger surface area, providing the clinician a confident surgical window to perform the procedure. Conclusions The anatomical basis of this study suggests that the medial proximal tibial bone harvest approach would have fewer serious structures in harm's way compared to the lateral; however, the lateral approach may be preferred for a subgroup of patients.

Ross, Alan; Delamarter, Taylor

2012-01-01

112

Analysis on the characteristics of pulsed laser proximity fuze's echo  

Microsoft Academic Search

With the rapid development of semiconductor technology and laser technology, a kind of proximity fuze named pulsed laser proximity fuze has been applied. Compared with other fuzes, pulsed laser proximity fuze has high ranging precision and strong resistance to artificial active interference. It is an important development tendency of proximity fuze. The paper analyze the characteristic of target echo of

Kun Wang; Huimin Chen

2011-01-01

113

Endoscopic Repair of Proximal Hamstring Avulsion  

PubMed Central

Hamstring muscle injuries are common in athletes and mostly consist of sprains at the myotendinous junction, which often respond well to conservative treatment. Proximal hamstring avulsion injuries, though less common, can be severely debilitating. This injury is often seen in water skiers but has been described in many other sports and in middle-aged patients. Complete avulsions in young and active individuals do not respond well to conservative treatment and may require surgical repair. In contrast, many partial tears may be treated nonoperatively. However, when symptoms continue despite a trial of extensive therapy, surgery may be warranted. Traditional surgery for proximal hamstring repair is performed with the patient in the prone position with an incision made longitudinally or along the gluteal fold, followed by identification of the torn tendons and fixation to the ischial tuberosity. We describe a novel surgical technique for endoscopic repair of proximal hamstring avulsion injuries.

Domb, Benjamin G.; Linder, Dror; Sharp, Kinzie G.; Sadik, Adam; Gerhardt, Michael B.

2013-01-01

114

Evaluation and Management of Proximal Humerus Fractures  

PubMed Central

Proximal humerus fractures are common injuries, especially among older osteoporotic women. Restoration of function requires a thorough understanding of the neurovascular, musculotendinous, and bony anatomy. This paper addresses the relevant anatomy and highlights various management options, including indication for arthroplasty. In the vast majority of cases, proximal humerus fractures may be treated nonoperatively. In the case of displaced fractures, when surgical intervention may be pursued, numerous constructs have been investigated. Of these, the proximal humerus locking plate is the most widely used. Arthroplasty is generally reserved for comminuted 4-part fractures, head-split fractures, or fractures with significant underlying arthritic changes. Reverse total shoulder arthroplasty is reserved for patients with a deficient rotator cuff, or highly comminuted tuberosities.

Khmelnitskaya, Ekaterina; Lamont, Lauren E.; Taylor, Samuel A.; Lorich, Dean G.; Dines, David M.; Dines, Joshua S.

2012-01-01

115

Klotho: a novel phosphaturic substance acting as an autocrine enzyme in the renal proximal tubule  

PubMed Central

Klotho has profound effects on phosphate metabolism, but the mechanisms of how Klotho affects phosphate homeostasis is unknown. We detected Klotho in the proximal tubule cell, brush border, and urinary lumen, where phosphate homeostasis resides. Increasing Klotho in the kidney and urine chronically by transgenic overexpression or acutely by intravenous infusion caused hypophosphatemia, phosphaturia from decreased proximal phosphate reabsorption, and decreased activity and protein of the principal renal phosphate transporter NaPi-2a. The phosphaturic effect was present in FGF23-null mice, indicating a direct action distinct from Klotho’s known role as a coreceptor for FGF23. Direct inhibition of NaPi-2a by Klotho was confirmed in cultured cells and in cell-free membrane vesicles characterized by acute inhibition of transport activity followed by decreased cell surface protein. Transport inhibition can be mimicked by recombinant ?-glucuronidase and is associated with proteolytic degradation and reduced surface NaPi-2a. The inhibitory effect of Klotho on NaPi-2a was blocked by ?-glucuronidase inhibitor but not by protease inhibitor. Klotho is a novel phosphaturic substance that acts as an enzyme in the proximal tubule urinary lumen by modifying glycans, which cause decreased transporter activity, followed by proteolytic degradation and possibly internalization of NaPi-2a from the apical membrane.—Hu, M. C., Shi, M., Zhang, J., Pastor, J., Nakatani, T., Lanske, B., Shawkat Razzaque, M., Rosenblatt, K. P., Baum, M. G., Kuro-o, M., Moe, O. W. Klotho: a novel phosphaturic substance acting as an autocrine enzyme in the renal proximal tubule.

Hu, Ming Chang; Shi, Mingjun; Zhang, Jianning; Pastor, Johanne; Nakatani, Teruyo; Lanske, Beate; Razzaque, M. Shawkat; Rosenblatt, Kevin P.; Baum, Michel G.; Kuro-o, Makoto; Moe, Orson W.

2010-01-01

116

Proximal femoral degeneration in growing broiler fowl.  

PubMed

The pathologies in proximal femora of broilers with lameness attributed to disorders of the proximal femur, including so-called 'femoral head necrosis', are described. Samples were collected from a variety of flocks, farms and production systems. Ten 'normal' broilers were also examined. Birds were identified by a characteristic lameness whereby they used a wing for support during locomotion and hip flexion (i.e. whilst sitting down). The appearance of the proximal femora at post mortem was used to place 67 proximal femora in three categories: (a) gross disintegration of the epiphysis, physis and/or metaphysis (43 samples); (b) epiphysiolysis-separation of the cartilaginous epiphysis from the underlying femoral metaphysis (growth plate) (17 samples) and (c) apparently normal (seven samples). Samples from each category were collected for mycoplasmology, virology and bacteriology. All the samples were negative for Mycoplasma, and there was no correlation between pathology and the presence or absence of viruses, but bacteria were cultured from about half the proximal femora and most of these femora showed histological evidence of bacterial infection. Although bacterial culture was negative, evidence of bacterial infections was seen in tissue sections from a further 15 proximal femora. Serial sections were required to find the foci on bacterial lesions. 'Femoral head necrosis' was not considered appropriate to describe the pathologies seen and the term proximal femoral degeneration (PFD) was adopted. Histological examination showed that PFD was most frequently due to a bacterial chondritis and osteomyelitis, with frequent involvement of surrounding tissues. Non-lame controls all had non-bacterial pathologies in the proximal femur which were also seen in many of the lame birds and may have provided a foci for the establishment of bacterial infections. The non-bacterial pathologies when severe were considered the cause of non-infectious PFD which would cause lameness in some cases. Epiphysiolysis was either a post or peri-mortem artefact, traumatic in origin, or could be attributed to underlying growth plate (physeal) pathology which in some cases was due to bacterial infection. PMID:18671021

Thorp, B H; Whitehead, C C; Dick, L; Bradbury, J M; Jones, R C; Wood, A

1993-06-01

117

Hallux proximal phalanx Akin-Scarf osteotomy.  

PubMed

Numerous hallux proximal phalanx osteotomies have been described, but the Akin-type varisation or adduction osteotomies are currently the most commonly used by foot and ankle surgeons. This article describes the hallux proximal phalanx Akin-Scarf osteotomy. This osteotomy combines the inherent stability of the Scarf-type osteotomy with the versatility of the Akin-type osteotomies to correct pathologic hallux abductus interphalangeus, hallux equinus, or an abnormal digital length pattern, and it is an invaluable tool during the global surgical approach used for hallux valgus repair. PMID:14729996

Roukis, Thomas S

2004-01-01

118

Traumatic instability of the proximal tibiofibular joint.  

PubMed

Proximal tibiofibular instability, seems to be an infrequently diagnosed abnormality, which occurs in isolation or in combination with fractures of the leg and ankle. Four types of instability are distinguished: subluxation, anterolateral dislocation, posteromedial dislocation and superior dislocation. The method of treatment depends on the type of dislocation and on the presence or absence of dysfunction of the peroneal nerve. The methods of treatment are described. Ten patients treated for this instability are presented. The use of radiographs to define the lesion is discussed. Radiographs, taken at follow-up, showed degenerative changes in the proximal tibiofibular joint in 8 of the 10 patients. PMID:7327731

Veth, R P; Klasen, H J; Kingma, L M

1981-09-01

119

Existence and convergence of best proximity points  

NASA Astrophysics Data System (ADS)

Consider a self map T defined on the union of two subsets A and B of a metric space and satisfying T(A)[subset of or equal to]B and T(B)[subset of or equal to]A. We give some contraction type existence results for a best proximity point, that is, a point x such that d(x,Tx)=dist(A,B). We also give an algorithm to find a best proximity point for the map T in the setting of a uniformly convex Banach space.

Eldred, A. Anthony; Veeramani, P.

2006-11-01

120

Effects of norepinephrine on the proximal tubular cells in perfused bullfrog kidney.  

PubMed

To study effects of norepinephrine (NE) on sodium and hydrogen ion transport, we used H(+)-, Ca2(+)-, or Na(+)-selective microelectrode and split-oil droplet techniques in doubly-perfused bullfrog proximal tubules. Peritubular membrane potential difference (EM), intracellular activities of Na+ ((Na)i) and Ca2+ ((Ca)i), and pH of the cytosol (pHi) and the lumen (pHTF) were monitored continuously during peritubular administration of NE (10(-6)-10(-7) M), phenylephrine (PHE, 10(-7) M), or dibutyryl cyclic AMP (db-cAMP, 10(-4) M). Results: (1) The peritubular application of NE produced: a) an enhancement of proximal fluid reabsorption, b) a transient fall of pHTF by about 0.2, c) a gradual hyperpolarization of EM and a slight decrease of (Na)i with oscillation, d) a mild cell acidification by about 0.05 pH, and e) an increase of (Ca)i. (2) The peritubular perfusion of PHE (alpha 1-agonist) caused: a) a transient fall of pHTF by about 0.3, b) a transient depolarization of EM and an increase of (Na)i, followed by sustained hyperpolarization of EM and a decrease of (Na)i, c) cytosolic acidification by about 0.1 pH, and d) a slight decrease of (Ca)i, followed by a sustained increase of (Ca)i. (3) The peritubular application of db-cAMP produced: a) a reduction of proximal fluid reabsorption, b) a transient elevation of pHTF by about 0.15, c) a hyperpolarization of EM with a gradual decrease of (Na)i, d) cytosolic alkalinization by about 0.15 pH, and e) biphasic change of (Ca)i: i.e., a slight increase of (Ca)i followed by a sustained decrease of (Ca)i.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2486238

Kubota, T; Hagiwara, N; Kubokawa, M; Fujimoto, M

1989-11-01

121

Proximity drawings in polynomial area and volume  

Microsoft Academic Search

Abstract We introduce a novel technique for drawing proximity graphs in polynomial area and volume. Previously known algorithms produce representations whose size increases exponentially with the size of the graph. This holds even when,we restrict ourselves to binary trees. Our method,is quite general and yields the first algorithms to construct (a) polynomial area weak Gabriel drawings of ternary trees ,(

Paolo Penna; Paola Vocca

2004-01-01

122

Capacitive Proximity Sensors With Additional Driven Shields  

NASA Technical Reports Server (NTRS)

Improved capacitive proximity sensors constructed by incorporating one or more additional driven shield(s). Sensitivity and range of sensor altered by adjusting driving signal(s) applied to shield(s). Includes sensing electrode and driven isolating shield that correspond to sensing electrode and driven shield.

Mcconnell, Robert L.

1993-01-01

123

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 proposed…

Veksler, Vladislav D.; Gray, Wayne D.; Schoelles, Michael J.

2013-01-01

124

Child labor, urban proximity, and household composition  

Microsoft Academic Search

Using detailed survey data from Nepal, this paper examines the determinants of child labor with a special emphasis on urban proximity. We find that children residing in or near urban centers attend school more and work less in total but are more likely to be involved in wage work or in a small business. The larger the urban center, the

Marcel Fafchamps; Jackline Wahba

2006-01-01

125

Best proximity point on nonlinear contractive condition  

NASA Astrophysics Data System (ADS)

In this paper, we obtain some proximity points of two mappings in metric space (X, d) by using (?, phi) contractive condition, where ? and phi are altering distance mappings. Our results generalized several well-known results in the literature. Also, we apply our results to get an application of common fixed point theorem of integral types.

Shatanawi, Wasfi

2013-04-01

126

Can the Proximal Femoral Nail be Improved?  

Microsoft Academic Search

Background: The Proximal Femoral Nail® (PFN) has an extra hip pin in the head-neck fragment, to prevent rotation of the fracture fragments. However, this hip pin brought along two unexpected complications: medial migration and cutout. In order to reduce the risk of migration and cutout, the hip pin should bear no or minimal load. For this reason, a modified PFN

Roger K. J. Simmermacher; Tobias Hüttl; Röbi Frigg; Peter Messmer; Michael Schütz; Andreas Lenich; Chris van der Werken

2005-01-01

127

Traumatic proximal tibiofibular dislocation with neurovascular injury  

PubMed Central

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.

Veerappa, Lokesh A; Gopalakrishna, Chetan

2012-01-01

128

Traumatic proximal tibiofibular dislocation with neurovascular injury.  

PubMed

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

2012-09-01

129

Proximity: Location, Time, and Opportunity to Communicate.  

ERIC Educational Resources Information Center

Traditional measures of proximity all share three common weaknesses: (1) they are based on ratio-level measurement of physical distance that may not correspond to "psychological distance;" (2) they measure distance as a fixed rather than variable quantity; and (3) they measure distance between pairs of individuals rather than larger groups of…

Kirste, Kenneth K.; Monge, Peter R.

130

Space Station Proximity Operations and Window Design.  

National Technical Information Service (NTIS)

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...

R. F. Haines

1988-01-01

131

Secluded and Proximate Illiteracy: Comparing Situations  

ERIC Educational Resources Information Center

Triplot is used to portray the three-dimensional concepts--literate, proximate illiterate and secluded illiterate. Pictographic portrayal complemented with a method proposed to calculate distance between situations enhances comparison. Illustration with Indian data explains change over time, rural-urban divide, and social gap.

Mishra, Srijit

2005-01-01

132

Protein biomarker validation via proximity ligation assays.  

PubMed

The ability to detect minute amounts of specific proteins or protein modifications in blood as biomarkers for a plethora of human pathological conditions holds great promise for future medicine. Despite a large number of plausible candidate protein biomarkers published annually, the translation to clinical use is impeded by factors such as the required size of the initial studies, and limitations of the technologies used. The proximity ligation assay (PLA) is a versatile molecular tool that has the potential to address some obstacles, both in validation of biomarkers previously discovered using other techniques, and for future routine clinical diagnostic needs. The enhanced specificity of PLA extends the opportunities for large-scale, high-performance analyses of proteins. Besides advantages in the form of minimal sample consumption and an extended dynamic range, the PLA technique allows flexible assay reconfiguration. The technology can be adapted for detecting protein complexes, proximity between proteins in extracellular vesicles or in circulating tumor cells, and to address multiple post-translational modifications in the same protein molecule. We discuss herein requirements for biomarker validation, and how PLA may play an increasing role in this regard. We describe some recent developments of the technology, including proximity extension assays, the use of recombinant affinity reagents suitable for use in proximity assays, and the potential for single cell proteomics. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge. PMID:23933049

Blokzijl, A; Nong, R; Darmanis, S; Hertz, E; Landegren, U; Kamali-Moghaddam, M

2014-05-01

133

Proximity algorithms for image models: denoising  

NASA Astrophysics Data System (ADS)

This paper introduces a novel framework for the study of the total-variation model for image denoising. In the model, the denoised image is the proximity operator of the total-variation evaluated at a given noisy image. The total-variation can be viewed as the composition of a convex function (the l1 norm for the anisotropic total-variation or the l2 norm for the isotropic total-variation) with a linear transformation (the first-order difference operator). These two facts lead us to investigate the proximity operator of the composition of a convex function with a linear transformation. Under the assumption that the proximity operator of a given convex function (e.g., the l1 norm or the l2 norm) can be readily obtained, we propose a fixed-point algorithm for computing the proximity operator of the composition of the convex function with a linear transformation. We then specialize this fixed-point methodology to the total-variation denoising models. The resulting algorithms are compared with the Goldstein-Osher split-Bregman denoising algorithm. An important advantage of the fixed-point framework leads us to a convenient analysis for convergence of the proposed algorithms as well as a platform for us to develop efficient numerical algorithms via various fixed-point iterations. Our numerical experience indicates that the methods proposed here perform favorably.

Micchelli, Charles A.; Shen, Lixin; Xu, Yuesheng

2011-04-01

134

Proximal sensory neuropathies of the Leg.  

PubMed

This article addresses the proximal sensory neuropathies of the leg, concentrating on those nerves that are purely sensory or have a predominately sensory onset. These include the lateral femoral cutaneous nerve, the ilioinguinal nerve, the genitofemoral nerve, and the posterior femoral cutaneous nerve. The obturator and femoral nerves are also summarily mentioned with respect to their sensory symptoms. PMID:10393758

Reid, V; Cros, D

1999-08-01

135

Proximate Optimality Principle Based Multipoint Tabu Search  

Microsoft Academic Search

This paper proposes a new Tabu Search with multi search points. In the proposed method, Proximate Optimality Principle (POP) is taken into consideration in order to improve its search efficiency. The proposed method is applied to some traveling salesman problems to verify the performance of the proposed algorithm.

Keiichiro Yasuda; Takaaki Nagaoka; Atsushi Ishigame

2008-01-01

136

Proximate optimality principle based Tabu Search  

Microsoft Academic Search

This paper proposes an algorithm-Multi Criteria Tabu Search coordinating the intensification and the diversification based on Proximate Optimality Principle (POP)-which has several advantages for solving combinatorial optimization problems. The proposed algorithm is applied to some traveling salesman problems which are typical combinatorial optimization problems in order to verify the performance of the proposed algorithm. The simulation results indicate that the

Keiichiro Yasuda; Takahiko Kanazawa

2003-01-01

137

Fiber optical ranging sensor for proximity fuse  

Microsoft Academic Search

A fiber optical ranging sensor used in laser proximity fuze is described in this paper. In the fuze, pulse laser diode (LD) is used as light source and trigger signal is generated by comparing the reflected light pulses with the reference pulses by a correlator after they were converted into electric signals by PIN photodiodes. Multi-mode fibers and integrated optical

Fang Du; Zeying Chi; Mingjun You; Wenjian Chen

1996-01-01

138

Substrate-induced modulation of ATP turnover in dog and rabbit proximal tubules  

Microsoft Academic Search

In dog proximal tubules in suspension, the addition of glucose increased significantly the ouabain-sensitive fraction of respiration, a response suppressed by phlorizin. The addition of a-methyl-d-glucoside (a-MG) had a modest effect and 3-O-methyl-d-glucoside (3-O-MG) had no effect. The different stimulation of the Na+,K+-ATPase activity elicited for each hexose could be explained by a different increment of net transepithelial flux of

J. Noël; A. Tejedor; P. Vinay; R. Laprade

1992-01-01

139

Experimental proximity matching of ArF scanners  

NASA Astrophysics Data System (ADS)

IC manufacturers have a strong demand for transferring a working process from one scanner to another. In an ideal transfer, a reticle set that produces devices within specification on a certain scanner has the same performance on another exposure tool. In real life, however, reticles employ optical proximity correction (OPC) which incorporates by definition the inherent optical fingerprint of a specific exposure tool and process. In order to avoid the additional cost of developing a new OPC model and acquiring a new reticle for each exposure tool, IC manufacturers therefore wish to 'match' the optical fingerprint of their scanners as closely as possible. In this paper, we report on the matching strategy that we developed to perform a tool-to-tool matching. We present experimental matching results for several tool combinations at numerical apertures (NA) 0.75, 0.85 and 1.2. Matching of exposure tools is obtained by determining the sensitivities to scanner parameter variations like NA, Sigma, Focus Drilling, Ellipticity and Dose from wafer data and/or simulations. These sensitivities are used to calculate the optimal scanner parameters for matching the two tools.

Bekaert, Joost; van Look, L.; de Bisschop, P.; van de Kerkhove, J.; Vandenberghe, G.,; Schreel, K.; Menger, J.; Schiffelers, G.; Knols, E.; van der Laan, H.; Willekers, R.

2008-11-01

140

Interaction of FXYD10 (PLMS) with Na,K-ATPase from shark rectal glands. Close proximity of Cys74 of FXYD10 to Cys254 in the a domain of the alpha-subunit revealed by intermolecular thiol cross-linking.  

PubMed

FXYD domain-containing proteins are tissue-specific regulators of the Na,K-ATPase that have been shown to have significant physiological implications. Information about the sites of interaction between some FXYD proteins and subunits of the Na,K-ATPase is beginning to emerge. We previously identified an FXYD protein in plasma membranes from shark rectal gland cells and demonstrated that this protein (FXYD10) modulates shark Na,K-ATPase activity. The present study was undertaken to identify the location of the C-terminal domain of FXYD10 on the alpha-subunit of Na,K-ATPase, using covalent cross-linking combined with proteolytic cleavage. Treatment of Na,K-ATPase-enriched membranes with the homobifunctional thiol cross-linker 1,4-bismaleimidyl-2,3-dihydroxybutane resulted in cross-linking of FXYD10 to the alpha-subunit. Cross-linking was not affected by preincubation with sodium or potassium but was significantly reduced after pre-incubation with the non-hydrolyzable ATP analog beta,gamma-methyleneadenosine 5'-triphosphate (AMP-PCP). A peptic assay was developed, in which pepsin treatment of Na,K-ATPase at low pH resulted in extensive cleavage of the alpha-subunit while FXYD10 was left intact. Proteolytic fragments of control and cross-linked preparations were isolated by immunoprecipitation and analyzed by gel electrophoresis. A proteolytic fragment containing FXYD10 cross-linked to a fragment from the alpha-subunit could be localized on SDS gels. Sequencing of this fragment showed the presence of FXYD10 as well as a fragment within the A domain of the alpha-subunit comprising 33 amino acids, including a single Cys residue, Cys254. Thus, regulation of Na,K-ATPase by FXYD10 occurs in part via cytoplasmic interaction of FXYD10 with the A domain of the shark alpha-subunit. PMID:15919665

Mahmmoud, Yasser Ahmed; Vorum, Henrik; Cornelius, Flemming

2005-07-29

141

Instability of the proximal tibiofibular joint.  

PubMed

Injury to the proximal tibiofibular joint is typically seen in athletes whose sports require violent twisting motions of the flexed knee. Instability of this joint may be in the anterolateral, posteromedial, or superior directions. With acute injury, patients usually complain of pain and a prominence in the lateral aspect of the knee. A closed reduction should be attempted in patients with acute dislocation. If this is unsuccessful, open reduction and stabilization of the joint with repair of the injured capsule and ligaments can be done. Patients with chronic dislocation or subluxation report lateral knee pain and instability with popping and catching, which may be confused with lateral meniscal injury. Symptoms of subluxation may be treated nonsurgically with physical therapies such as activity modification, supportive straps, and knee strengthening. For patients with chronic pain or instability, surgical options include arthrodesis, fibular head resection, and proximal tibiofibular joint capsule reconstruction. PMID:12670138

Sekiya, Jon K; Kuhn, John E

2003-01-01

142

[Arthroscopic fracture management in proximal humeral fractures].  

PubMed

Arthroscopy has become increasingly more established in the treatment of proximal humeral fractures. In addition to the known advantages of minimally invasive surgery fracture and implant positioning can be optimized and controlled arthroscopically and relevant intra-articular concomitant pathologies (e.g. biceps tendon complex and rotator cuff) can be diagnosed and treated. Arthroscopic techniques have proven to be advantageous in the treatment of various entities of greater tuberosity fractures, lesser tuberosity fractures (suture bridging technique) and subcapital humeral fractures (arthroscopic nailing). This article presents an overview on innovative arthroscopic modalities for treating proximal humeral fractures, describes the surgical techniques and the advantages compared to open procedures as well as initial clinical results. PMID:23515643

Lill, H; Katthagen, C; Jensen, G; Voigt, C

2013-04-01

143

Clinical Impact of Proximal Autosomal Imbalances  

PubMed Central

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.

Hamid, AB; Weise, A; Voigt, M; Bucksch, M; Kosyakova, N; Liehr, T; Klein, E

2012-01-01

144

Dual-Fiberoptic Microcantilever Proximity Sensor  

SciTech Connect

Microcantilevers are key components of many Micro-Electro-Mechanical Systems (MEMS) and Micro-Optical-Electro-Mechanical Systems (MOEMS) because slight changes to them physically or chemically lead to changes in mechanical characteristics. An inexpensive dual-fiberoptic microcantilever proximity sensor and model to predict its performance are reported here. Motion of a magnetic-material-coated cantilever is the basis of a system under development for measuring magnetic fields. The dual fiber proximity sensor will be used to monitor the motion of the cantilever. The specific goal is to sense induction fields produced by a current carrying conductor. The proximity sensor consists of two fibers side by side with claddings in contact. The fiber core diameter, 50 microns, and cladding thickness, 10 microns, are as small as routinely available commercially with the exception of single mode fiber. Light is launched into one fiber from a light-emitting diode (LED). It emerges from that fiber and reflects from the cantilever into the adjacent receiving fiber connected to a detector. The sensing end is cast molded with a diameter of 3-mm over the last 20-mm, yielding a low profile sensor. This reflective triangulation approach is probably the oldest and simplest fiber proximity sensing approach, yet the novelty here is in demonstrating high sensitivity at low expense from a triangular microstructure with amorphous magnetic coatings of iron, cobalt, permalloy, etc. The signal intensity versus distance curve yields an approximate gaussian shape. For a typical configuration, the signal grows from 10% to 90% of maximum in traversing from 6 to 50 microns from a coated cantilever. With signal levels exceeding a volt, nanometer resolution should be readily achievable for periodic signals.

Goedeke, S.M.

2001-08-08

145

Transport Magnetic Proximity Effects in Platinum  

NASA Astrophysics Data System (ADS)

Platinum (Pt) metal, being nonmagnetic and with a strong spin-orbit coupling interaction, has been central in detecting the pure spin current and establishing most of the recent spin-based phenomena. Magnetotransport measurements, both electrical and thermal, conclusively show strong ferromagnetic characteristics in thin Pt films on the ferromagnetic insulator due to the magnetic proximity effects. The pure spin current phenomena measured by Pt, including the inverse spin Hall and the spin Seebeck effects, are thus contaminated and not exclusively established.

Huang, S. Y.; Fan, X.; Qu, D.; Chen, Y. P.; Wang, W. G.; Wu, J.; Chen, T. Y.; Xiao, J. Q.; Chien, C. L.

2012-09-01

146

Proximal Sciatic Nerve Intraneural Ganglion Cyst  

PubMed Central

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.

Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.

2009-01-01

147

Proximal Splitting Methods in Signal Processing  

Microsoft Academic Search

\\u000a The proximity operator of a convex function is a natural extension of the notion of a projection operator onto a convex set.\\u000a This tool, which plays a central role in the analysis and the numerical solution of convex optimization problems, has recently\\u000a been introduced in the arena of inverse problems and, especially, in signal processing, where it has become increasingly

Patrick L. Combettes; Jean-Christophe Pesquet

2009-01-01

148

Proximity algorithms for image models: denoising  

Microsoft Academic Search

This paper introduces a novel framework for the study of the total-variation model for image denoising. In the model, the denoised image is the proximity operator of the total-variation evaluated at a given noisy image. The total-variation can be viewed as the composition of a convex function (the l1 norm for the anisotropic total-variation or the l2 norm for the

Charles A. Micchelli; Lixin Shen; Yuesheng Xu

2011-01-01

149

Endoscopic Proximal Hamstring Repair and Ischial Bursectomy  

PubMed Central

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.

Dierckman, Brian D.; Guanche, Carlos A.

2012-01-01

150

Topological Proximity Effects in Graphene Nanoribbon Heterostructures  

NASA Astrophysics Data System (ADS)

Topological insulators (TI) are bulk insulators that possess robust chiral conducting states along their interfaces with normal insulators. A tremendous research effort has recently been devoted to TI-based heterostructures, in which conventional proximity effects give rise to many exotic physical phenomena. Here we establish the potential existence of ``topological proximity effect'' at the interface of a topological graphene nanoribbon (GNR) and a normal GNR. Specifically, we show that the location of the topological edge states exhibits versatile tunability as a function of the interface orientation, as well as the strengths of the interface coupling and spin-orbit coupling in the normal GNR. For zigzag and bearded GNRs, the topological edge state can be tuned to be either at the interface or outer edge of the normal ribbon. For armchair GNR, the potential location of the topological edge state can be further enriched to be at the edge of or within the normal ribbon, at the interface, or diving into the topological GNR. We also discuss potential experimental realization of the predicted topological proximity effects, which may pave the way for integrating the salient functionality of TI and graphene in future device applications.

Zhang, Gufeng; Li, Xiaoguang; Wu, Guangfen; Wang, Jie; Culcer, Dimitrie; Kaxiras, Efthimios; Zhang, Zhenyu

2013-03-01

151

Bilateral, atraumatic, proximal tibiofibular joint instability.  

PubMed

Dislocation of the tibiofibular joint is rare and usually results from a traumatic event. Only 1 case of atraumatic proximal tibiofibular joint instability in a 14-year-old girl has been reported in the literature, however this condition might occur more frequently than once thought. A wide range of treatment options exist for tibiofibular dislocations. Currently, the first choice is a conservative approach, and when this fails, surgical means such as resection of the fibula head, arthrodesis, and reconstruction are considered. However, no consensus exists on the most effective treatment. This article reports a unique case of bilateral, atraumatic, proximal tibia and fibular joint instability involving a 30-year-old man with a 20-year history of pain and laxity in the right knee. The patient had no trauma to his knees; he reported 2 immediate family members with similar complaints, which suggests that this case is likely congenital. After conservative approaches proved to be ineffective, the patient underwent capsular reconstruction using free autologous gracilis tendon. At 6-month postoperative follow-up, the patient was pain free with no locking and instability. He then underwent surgery on the left knee. At 1-year follow-up after the second surgery, the patient had no symptoms or restrictions in mobility. We provide an alternative surgical approach to arthrodesis and resection for the treatment of chronic proximal tibiofibular instability. In the treatment of chronic tibiofibular instability, we believe that reconstruction of the tibiofibular joint is a safe and effective choice. PMID:21323280

Morrison, Troy D; Shaer, James A; Little, Jill E

2011-02-01

152

Proximal myopathy: diagnostic approach and initial management.  

PubMed

Proximal myopathy presents as symmetrical weakness of proximal upper and/or lower limbs. There is a broad range of underlying causes including drugs, alcohol, thyroid disease, osteomalacia, idiopathic inflammatory myopathies (IIM), hereditary myopathies, malignancy, infections and sarcoidosis. Clinical assessment should aim to distinguish proximal myopathy from other conditions that can present similarly, identify patients who need prompt attention, like those with cardiac, respiratory or pharyngeal muscle involvement, and determine underlying cause of myopathy. Initial evaluation should include simple tests, like creatine kinase, thyroid function and (25)OH vitamin D levels, but further evaluation including neurophysiological studies, muscle imaging and muscle biopsy should be considered for patients in whom no toxic, metabolic or endocrine cause is found, and in those with clinical features suggestive of inflammatory or hereditary myopathy. Additionally, screening for malignancy and testing for anti-Jo1 antibody is indicated for selected patients with IIM. Management depends on underlying cause, and includes measures, such as removal of offending agent, correction of endocrine or metabolic problem, corticosteroids and immunosuppressive therapy for IIM, and physical therapy, rehabilitation and genetic counselling for muscular dystrophies. PMID:23596213

Suresh, Ernest; Wimalaratna, Sunil

2013-08-01

153

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

2013-09-01

154

Tenofovir Renal Proximal Tubular Toxicity Is Regulated By OAT1 and MRP4 Transporters  

PubMed Central

Tenofovir disoproxil fumarate (TDF) is an oral prodrug and acyclic nucleotide analog of adenosine monophosphate that inhibits HIV-1 (HIV) reverse transcriptase. A growing subset of TDF-treated HIV+ individuals presented with acute renal failure, suggesting tenofovir-associated kidney-specific toxicity. Our previous studies using an HIV transgenic mouse model (TG) demonstrated specific changes in renal proximal tubular mitochondrial DNA (mtDNA) abundance. Nucleosides are regulated in biological systems via transport and metabolism in cellular compartments. In this study, the role(s) of organic anion transporter type 1 (OAT1) and multidrug-resistant protein type 4 (MRP4) in transport and regulation of tenofovir in proximal tubules were assessed. Renal toxicity was assessed in kidney tissues from OAT1 knock-out (KO) or MRP4 KO compared to wild-type (WT, C57BL/6) mice following treatment with TDF (0.11 mg/day), didanosine (ddI, a related adenosine analog, 0.14 mg/day) or vehicle (0.1 M NaOH) daily gavage for 5 wks. Laser-capture microdissection (LCM) was used to isolate renal proximal tubules for molecular analyses. mtDNA abundance and ultrastructural pathology were analyzed. mtDNA abundance in whole-kidneys from both KO and WT was unchanged regardless of treatment. Renal proximal tubular mtDNA abundance from OAT1 KO also remained unchanged, suggesting prevention of TDF toxicity due to loss of tenofovir transport into proximal tubules. In contrast, renal proximal tubules from MRP4 KO exhibited increased mtDNA abundance following TDF treatment compared to WT littermates, suggesting compensation. Renal proximal tubules from TDF treated WT and MRP4 KO exhibited increased numbers of irregular mitochondria with sparse, fragmented cristae compared to OAT1 KO. Treatment with ddI had a compensatory effect on mtDNA abundance in OAT1 KO but not in MRP4 KO. Both OAT1 and MRP4 have a direct role in transport and efflux of tenofovir, regulating levels of tenofovir in proximal tubules. Disruption of OAT1 activity prevents tenofovir toxicity but loss of MRP4 can lead to increased renal proximal tubular toxicity. These data help explain mechanisms of human TDF renal toxicity.

Kohler, James J.; Hosseini, Seyed H.; Green, Elgin; Abuin, Allison; Ludaway, Tomika; Russ, Rodney; Santoianni, Robert; Lewis, William

2011-01-01

155

Proximity matching for ArF and KrF scanners  

NASA Astrophysics Data System (ADS)

There are many IC-manufacturers over the world that use various exposure systems and work with very high requirements in order to establish and maintain stable lithographic processes of 65 nm, 45 nm and below. Once the process is established, manufacturer desires to be able to run it on different tools that are available. This is why the proximity matching plays a key role to maximize tools utilization in terms of productivity for different types of exposure tools. In this paper, we investigate the source of errors that cause optical proximity mismatch and evaluate several approaches for proximity matching of different types of 193 nm and 248 nm scanner systems such as set-get sigma calibration, contrast adjustment, and, finally, tuning imaging parameters by optimization with Manual Scanner Matcher. First, to monitor the proximity mismatch, we collect CD measurement data for the reference tool and for the tool-to-be-matched. Normally, the measurement is performed for a set of line or space through pitch structures. Secondly, by simulation or experiment, we determine the sensitivity of the critical structures with respect to small adjustment of exposure settings such as NA, sigma inner, sigma outer, dose, focus scan range etc. that are called 'proximity tuning knobs'. Then, with the help of special optimization software, we compute the proximity knob adjustment that has to be applied to the tool-to-be-matched to match the reference tool. Finally, we verify successful matching by exposing on the tool-to-be-matched with tuned exposure settings. This procedure is applicable for inter- and intra scanner type matching, but possibly also for process transfers to the design targets. In order to illustrate the approach we show experimental data as well as results of imaging simulations. The set demonstrate successful matching of critical structures for ArF scanners of different tool generations.

Kim, Young Ki; Pohling, Lua; Hwee, Ng Teng; Kim, Jeong Soo; Benyon, Peter; Depre, Jerome; Hong, Jongkyun; Serebriakov, Alexander

2009-03-01

156

Acoustic proximity ranging in the presence of secondary echoes  

Microsoft Academic Search

Proximity ranging is very important in many applications. Ultrasonic sensors have proven to be very cost effective tools for this purpose. Most of the currently available time-of-flight based acoustic proximity ranging systems use the conventional matched filter based time delay estimation approaches to measure short distances between proximity objects. However, in the presence of strong and closely spaced secondary echoes,

Xi Li; Renbiao Wu; Srihari Rasmi; Jian Li; Mark Sheplak

2003-01-01

157

Incidence of Proximal Adjacent Failure in Adult Lumbar Deformity Correction Based on Proximal Fusion Level  

PubMed Central

Study Design Retrospective study. Purpose To review the results and proximal adjacent problems of long fusion (more than 4 levels) according to the level of proximal fusion (L2~T9) in adult lumbar deformity using pedicle screw fixation. Overview of Literature There are few written reports concerning proximal adjacent segmental failure according to the level of proximal fusion in adult lumbar deformity. Methods The radiographs and clinical records of thirty-five patients (30 females, 5 males) of adult lumbar deformity with more than 2-year follow-up after surgery were analyzed. The average age was 62 years (range, 38~75). All patients were divided into three groups according to the level of proximal fusion: Group 1 (n=14) fusion up to L1 or L2; Group 2 (n=14) fusion up to T11 or T12; and Group 3 (n=7) fusion up to T9 or T10. Results The preoperative coronal curve of 28±14° was corrected to 9±7° immediately after surgery and 11±7° at the final follow-up. The preoperative local kyphosis of 24±12° was corrected to -1±10° immediately after surgery and 1±11° at the final follow-up. The lumbar lordosis was 14±18° before surgery; 27±11° after surgery; and 16±12° at the final follow- up. The parameters of coronal and sagittal balance were improved in all patients after surgery, except one patient in group 2 who showed coronal imbalance due to over-correction. Sagittal imbalance at the most recent follow-up was detected in 10 patients with significant difference between the groups; 5 (36%) in Group 1, 5 (36%) in Group 2, and none in Group 3. Proximal adjacent segmental problems that are consisted with proximal disc degeneration with kyphosis, compression fractures above the fusion and screw failure proximal to the end of the fusion were observed in 15 patients with significant difference between the groups; 7 (50%) in Group 1, 7 (50%) in Group 2, and 1 (14%) in Group 3. There was 1 superficial infection and 2 transient neurologies. Conclusions Fusion up to throacolumbar junction (L2~T11) in surgical treatment of adult lumbar deformity had more proximal adjacent problems with poorer results. Fusion higher than T10 is recommended for adult lumbar deformity.

Kim, Sung-Soo; Suk, Se-Il

2007-01-01

158

Revision of the Deficient Proximal Femur With a Proximal Femoral Allograft  

PubMed Central

Substantial bone loss is frequently encountered with revision hip arthroplasty. A proximal femoral allograft may be used to reconstitute bone stock in the multiply revised femur with segmental bone loss of greater than 5 cm. We retrospectively reviewed 92 patients (93 hips) who underwent such proximal femoral allografts. The average age at the surgery was 61 years. The average number of previous revision procedures was 2.5. Six patients were lost to followup. Thirty-four of 36 deceased patients had the original proximal femoral allograft at the time of death. The minimum followup for the 50 remaining patients was 15 years (average, 16.2 years; range, 15–22 years). Analysis included survivorship and radiographic assessment. Of the 50 patients reviewed, two had a failed reconstruction due to infection, six for aseptic loosening, three for nonunion, and four for dislocation. Revision of the proximal femoral allograft for all reasons excluding the acetabulum was performed in seven patients. At last followup, 42 patients (84%) had a well-functioning construct. Proximal femoral allograft for revision hip arthroplasty in femoral segmental bone loss is a durable alternative in most patients for a complex problem. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Safir, Oleg; Kellett, Catherine F.; Flint, Michael; Backstein, David

2008-01-01

159

Kinetic transport model for cellular regulation of pH and solute concentration in the renal proximal tubule.  

PubMed Central

An open circuit kinetic model was developed to calculate the time course of proximal tubule cell pH, solute concentrations, and volume in response to induced perturbations in luminal or peritubular fluid composition. Solute fluxes were calculated from electrokinetic equations containing terms for known carrier saturabilities, allosteric dependences, and ion coupling ratios. Apical and basolateral membrane potentials were determined iteratively from the requirements of cell electroneutrality and equal opposing transcellular and paracellular currents. The model converged to membrane potentials accurate to 0.05% in one to four iterations. Model variables included cell concentrations of Na, K, HCO3, glucose, pH (uniform CO2), volume, and apical and basolateral membrane potentials. The basic model contained passive apical membrane transport of Na/H, Na/glucose, H and K, basolateral transport of Na/3HCO3, K, H, and glucose, and paracellular transport of Na, K, Cl, and HCO3; apical H and basolateral 3Na/2K-ATPases were present. Apical Na/H and basolateral K transport were regulated allosterically by pH. Apical Na/H transport, basolateral Na/3HCO3 transport, and the 3Na/2K-ATPase were saturable. Model parameters were chosen from data in the rat proximal tubule. Model predictions for the magnitude and time course of cell pH, Na, and membrane potential in response to rapid changes in apical and peritubular Na and HCO3 were in excellent agreement with experiment. In addition, the model requires that there exist an apical H-ATPase, basolateral Na/3HCO3 transport saturable with HCO3, and electroneutral basolateral K transport.

Verkman, A S; Alpern, R J

1987-01-01

160

Proximal tibiofibular joint: anatomic-pathologic-radiographic correlation.  

PubMed

An anatomic-pathologic-radiographic study of the proximal tibiofibular joint was undertaken. This synovial articulation between the proximal tibia and fibula may communicate with the knee joint in 10% of adults. Radiography of the normal proximal tibiofibular articulation outlines a consistent relationship between the proximal portions of the tibia and fibula. Disruption of this normal relationship is indicative of anterolateral or posteromedial subluxation or dislocation. Articular disorders of this joint include reheumatoid arthritis and septic arthritis. In the latter, initial alterations of the knee joint may subsequently extend to involve the proximal tibiofibular joint, illustrating the potential communication between these two articulations. PMID:97965

Resnick, D; Newell, J D; Guerra, J; Danzig, L A; Niwayama, G; Goergen, T G

1978-07-01

161

Scintillation proximity assay using polymeric membranes  

SciTech Connect

Liquid scintillation counting (LSC) is typically used to quantify electron emitting isotopes. In LSC, radioactive samples are dissolved in an organic fluor solution (scintillation cocktail) to ensure that the label is close enough to the fluor molecules to be detected. Although efficient, scintillation cocktail is neither specific or selective for samples labeled with the same radioisotope. Scintillation cocktail is flammable posing significant health risks to the user and is expensive to purchase and discard. Scintillation Proximity Assay (SPA) is a radioanalytical technique where only those radiochemical entities (RCE's) bound to fluor containing matrices are detected. Only bound RCE's are in close enough proximity the entrapped fluor molecules to induce scintillations. Unbound radioligands are too far removed from the fluor molecules to be detected. The research in this dissertation focused on the development and evaluation of fluor-containing membranes (scintillation proximity membranes, SP membranes) to be used for specific radioanalytical techniques without using scintillation cocktail. Polysulfone and PVC SP membranes prepared in our laboratory were investigated for radioimmunossay (RIA) where only bound radioligand is detected, thereby eliminating the separation step impeding the automation of RIA. These SP membranes performed RIA where the results were nearly identical to commercial SP microbeads. SP membranes functionalized with quaternary ammonium hydroxide moieties were able to trap and quantify [sup 14]CO[sub 2] without using liquid scintillation cocktail. RCE's bound in the pore structure of SP membranes are intimate with the entrapped fluor providing the geometry needed for high detection efficiencies. Absorbent SP membranes were used in radiation surveys and were shown to be as effective as conventional survey techniques using filter paper and scintillation cocktail.

Mansfield, R.K.

1992-01-01

162

Unilateral Isolated Proximal Femoral Focal Deficiency  

PubMed Central

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.

Doger, Emek; Kopuk, Sule Y.; Cak?roglu, Yigit; Cak?r, Ozgur; Yucesoy, Gulseren

2013-01-01

163

Isolated dislocation of the proximal tibiofibular joint.  

PubMed

We have reported the case of an anterolateral dislocation of the proximal tibiofibular joint in a soccer player, apparently the second case in the literature. As in that reported by O'Rourke and McManus, this patient was attempting to gain his balance and this may indeed be an important contributing factor. Ogden's classification is now well accepted and has been reviewed along with a discussion of the mechanisms of injury. The diagnosis can generally be made by clinical examination and confirmed by roentgenographs. Treatment usually consists of closed reduction with 3 weeks of casting. In complicated cases, however, resection of the fibular head may be required. PMID:3944842

Thomason, P A; Linson, M A

1986-02-01

164

Recreation activity monitoring system using proximity sensors.  

PubMed

This paper describes a recreational-activity monitoring system that records the existence of tools (removed or not from a predefined place) that are used in the recreation activities. The system is composed of three types (infrared, ultrasonic, and RFID) of proximity sensors to adapt to various sizes of the target object. The timings of when the target object was removed and returned are monitored. Simple experiments showed that the detectable range of the system was approximately 60 approximately 100 mm, and concluded that the infrared and ultrasonic sensors were useful for relatively large objects, and the RFID technology was suitable for small objects. PMID:19964355

Tsukamoto, Sosuke; Tsumagari, Yuko; Hoshino, Hiroshi; Tamura, Toshiyo

2009-01-01

165

Fiber optical ranging sensor for proximity fuse  

NASA Astrophysics Data System (ADS)

A fiber optical ranging sensor used in laser proximity fuze is described in this paper. In the fuze, pulse laser diode (LD) is used as light source and trigger signal is generated by comparing the reflected light pulses with the reference pulses by a correlator after they were converted into electric signals by PIN photodiodes. Multi-mode fibers and integrated optical devices are used in the system so that the structure can be more compact. Optical fiber delay line is used to offer precise delay time for reference channel.

Du, Fang; Chi, Zeying; You, Mingjun; Chen, Wenjian

1996-09-01

166

Proximal femoral nail antirotation (PFNA) for treatment of osteoporotic proximal femoral fractures  

Microsoft Academic Search

Background  Unstable trochanteric fractures have been an enigma for the orthopedic surgeon in the community because of unpredictable results.\\u000a Cephalic intramedullary nails with proximal antirotation device are the treatment of choice for such patients.\\u000a \\u000a \\u000a \\u000a \\u000a Purpose  To report outcomes of 36 consecutive patients treated with a proximal femoral nail (PFNA) for osteoporotic trochanteric femoral\\u000a fractures.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The patients included 20 men and 16 women,

A. Raviraj; Ashish Anand; Murali Chakravarthy; Sanjay Pai

167

Elemental microanalysis of organelles in proximal tubules. I. Alterations in transport and metabolism.  

PubMed

Oxygen deprivation to the kidney causes a multifactorial series of morphological, physiological, and biochemical alterations that occur as a function of time. One of the earliest events involves significant changes in the cellular contents of the physiologically important elements (ions) Na and K. Controversy exists as to the nature of changes in the content of the regulatory ion Ca, in either its free or bound form, and much less is known regarding in situ distribution and amounts of other elements such as Mg, P, S, and Cl during physiological or pathophysiological states. The objective of these studies was to evaluate element compartmentation in proximal renal tubules by using quantitative electron probe x-ray microanalysis, during specific conditions which are at least partially manifested during oxygen deprivation. Cells from control proximal tubule suspensions were compared with those exposed to (1) ouabain, to inhibit (Na+, K+)-ATPase; (2) mitochondrial uncouplers, to rapidly deplete ATP content; or (3) calcium ionophores, to cause a rapid elevation in cytoplasmic free calcium. In parallel with electron probe x-ray microanalysis imaging of subcellular elemental content, total cell potassium and ATP contents, enzyme release, oxygen consumption, cytoplasmic free calcium levels, and ultrastructural alterations were assessed. Results indicated that ATP depletion was, in the short term, more deleterious to renal proximal tubules than any of the tested ionic alterations. Intracellular organelles including mitochondria and nuclei appeared to be readily permeable to Na, K, and Cl, altering their concentrations of these ions in parallel with cytoplasmic concentrations. Lysosomes exhibited evidence of Cl accumulation, consistent with an inwardly directed proton ATPase with accompanying Cl transport. Whereas in the cytoplasm Na, K and Cl appeared to be mostly free, a large fraction of these ions within intracellular organelles seemed bound. PMID:1912393

LeFurgey, A; Spencer, A J; Jacobs, W R; Ingram, P; Mandel, L J

1991-06-01

168

Multiplication-stimulating activity-induced alkalinization of canine renal proximal tubular cells  

SciTech Connect

The actions of a variety of polypeptide growth factors on isolated cells are thought to be initiated by stimulation of Na/sup +/-H/sup +/ exchange across the plasma membranes of the cells resulting in intracellular alkalinization. To determine whether insulin-like growth factors (IGFs) exert actions through such a mechanism, the authors incubated suspensions of canine renal proximal tubular segments with insulin or IGF I or with multiplication-stimulating activity (MSA)/IGF II. Changes in intracellular pH were detected by measurements of the distribution of (/sup 14/C)5,5-dimethoxazolidine-2,4-dione. Incubation of segments with 10/sup +9/ M MSA under conditions such that extracellular (Na/sup +/)> intracellular (Na/sup +/) effected intracellular alkalinization detectable within 1-2 min. Alkalinization was not observed under conditions where this gradient was not present. Alkalinization was not prevented by inclusion of 1mM 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid or 1 mM ouabain in incubations, but was inhibited by amiloride. Incubation of proximal tubular segments with as little as 10/sup +11/ M MSA effected intracellular alkalinization. Incubation with as much as 10/sup -6/ M insulin or IGF I did not. Our findings are consistent with an action of MSA/IGF II to stimulate Na/sup +/-H/sup +/ exchange across the plasma membrane of the renal proximal tubular cell. It is possible that the stimulation represents a mechanism by which actions of IGF II are initiated in growth factor-sensitive cells.

Mellas, J.; Gavin, J.R. III; Hammerman, M.R.

1986-11-05

169

Cephalomedullary nailing for proximal femoral fractures.  

PubMed

From May 1999 to April 2002, we treated 14 patients with subtrochanteric femoral fractures and seven patients with ipsilateral fractures of the femoral neck and shaft using a second-generation cephalomedullary interlocked nail. Patients mean age was 36 (20-60) years, and 19 fractures were caused by high-energy trauma. Four patients had associated injuries. The average follow-up was 23 (16-30) months. Per-operatively, we had problems in locating the entry portal in four patients, and one nail was driven through the inter-condylar notch. All fractures except two united. One patient had non-union of the femoral neck and one of both neck and shaft. One patient united with shortening of more than 1.5 cm and varus angulation at the fracture site. Two patients had loosening and backing out of the proximal screw. The second-generation cephalomedullary nail is a suitable treatment option for proximal femoral fractures, but it requires a high degree of accuracy and technical expertise. PMID:15647914

Kakkar, Rahul; Kumar, S; Singh, A K

2005-02-01

170

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

2014-05-01

171

Actions of isoproterenol in frog proximal tubules.  

PubMed

In the present work, we compared biochemical and electrophysiological actions of isoproterenol on frog proximal tubular cells by using tubule suspensions and giant entities obtained by cell fusion. Isoproterenol (ISO) dose-dependently stimulated cAMP production in tubule suspension and depolarized the "giant cell" membrane. Both effects were triggered by beta receptor occupancy, but strongly differed in their concentration-dependency, since depolarization occurred with an ISO concentration as low as 10(-12) mol/l whereas cAMP accumulation could be seen only with more than 10(-8) mol/l ISO. ISO-induced membrane depolarization was mimicked by forskolin which directly stimulated the catalytic subunit of adenylyl cyclase. In both isoproterenol- and forskolin-stimulated giant cells, membrane depolarization was accompanied by a decrease in membrane conductance, and both effects were inhibited by tetraethylammonium (TEA) and 4-aminopyridine (4-AP). On the other hand, ISO- and forskolin-induced cAMP production were not affected by TEA. The present data thus show that isoproterenol produces two independent effects in frog proximal tubule: it depolarizes the cell membrane by blocking a K+ conductance and activates adenylyl cyclase. PMID:7794685

Belachgar, F; Discala-Blondeau, F; Tondelier, D; Baudouin-Legros, M; Anagnostopoulos, T

1995-02-01

172

Congenital anomalies and proximity to landfill sites.  

PubMed

The occurrence of congenital anomalies in proximity to municipal landfill sites in the Eastern Region (counties Dublin, Kildare, Wicklow) was examined by small area (district electoral division), distance and clustering tendancies in relation to 83 landfills, five of which were major sites. The study included 2136 cases of congenital anomaly, 37,487 births and 1423 controls between 1986 and 1990. For the more populous areas of the region 50% of the population lived within 2-3 km of a landfill and within 4-5 km for more rural areas. In the area-level analysis, the standardised prevalence ratios, empirical and full Bayesian modelling, and Kulldorff's spatial scan statistic found no association between the residential area of cases and location of landfills. In the case control analysis, the mean distance of cases and controls from the nearest landfill was similar. The odds ratios of cases compared to controls for increasing distances from all landfills and major landfills showed no significant difference from the baseline value of 1. The kernel and K methods showed no tendency of cases to cluster in relationship to landfills. In conclusion, congenital anomalies were not found to occur more commonly in proximity to municipal landfills. PMID:15055915

Boyle, E; Johnson, H; Kelly, A; McDonnell, R

2004-01-01

173

Obesity and Supermarket Access: Proximity or Price?  

PubMed Central

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.

Aggarwal, Anju; Hurvitz, Philip M.; Monsivais, Pablo; Moudon, Anne V

2012-01-01

174

Proximal femoral osteotomy in cerebral palsy.  

PubMed

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

1980-09-01

175

Hfq proximity and orientation controls RNA annealing  

PubMed Central

Regulation of bacterial gene networks by small non-coding RNAs (sRNAs) requires base pairing with messenger RNA (mRNA) targets, which is facilitated by Hfq protein. Hfq is recruited to sRNAs and mRNAs through U-rich- and A-rich-binding sites, respectively, but their distance from the sRNA–mRNA complementary region varies widely among different genes. To determine whether distance and binding orientation affect Hfq’s chaperone function, we engineered ‘toy’ RNAs containing strong Hfq-binding sites at defined distances from the complementary target site. We show that RNA annealing is fastest when the distal face of Hfq binds an A-rich sequence immediately 3? of the target. This recruitment advantage is lost when Hfq binds >20?nt away from the target, but is partially restored by secondary structure that shortens this distance. Although recruitment through Hfq’s distal face accelerates RNA annealing, tight binding of six Us to Hfq’s proximal face inhibits annealing. Finally, we show that ectopic A-rich motifs dramatically accelerate base pairing between DsrA sRNA and a minimal rpoS mRNA in the presence of Hfq, demonstrating that proximity and orientation predict the activity of Hfq on long RNAs.

Panja, Subrata; Woodson, Sarah A.

2012-01-01

176

Proximal intentional neglect: a case study.  

PubMed Central

Although neglect has been demonstrated in the horizontal, vertical, and radial planes of space and has been attributed to sensory-attentional, motor-intentional, and representational deficits, motor intentional neglect in the radial plane has not been previously described. A patient who had a right parietal infarct was tested with a modified cancellation task that uses a fixed window, thereby controlling attentional demands and allowing one to dissociate between intentional and representational neglect. This patient showed proximal (radial) intentional neglect (a failure to move towards or in proximal space). Unlike controls whose search times decreased with increasing window size, our patient showed no change in search time as a function of window size. This pattern of behaviour suggests that the patient's search strategy does not incorporate factors such as the relation between a fixed target space and a variably sized aperture, but rather was based on the allocation of a certain amount of resources for a fixed period of time after which, regardless of performance, the patient would stop searching.

Gold, M; Shuren, J; Heilman, K M

1994-01-01

177

Protein structure alignment beyond spatial proximity  

PubMed Central

Protein structure alignment is a fundamental problem in computational structure biology. Many programs have been developed for automatic protein structure alignment, but most of them align two protein structures purely based upon geometric similarity without considering evolutionary and functional relationship. As such, these programs may generate structure alignments which are not very biologically meaningful from the evolutionary perspective. This paper presents a novel method DeepAlign for automatic pairwise protein structure alignment. DeepAlign aligns two protein structures using not only spatial proximity of equivalent residues (after rigid-body superposition), but also evolutionary relationship and hydrogen-bonding similarity. Experimental results show that DeepAlign can generate structure alignments much more consistent with manually-curated alignments than other automatic tools especially when proteins under consideration are remote homologs. These results imply that in addition to geometric similarity, evolutionary information and hydrogen-bonding similarity are essential to aligning two protein structures.

Wang, Sheng; Ma, Jianzhu; Peng, Jian; Xu, Jinbo

2013-01-01

178

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)

1997-01-01

179

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)

1998-01-01

180

An improved proximity force approximation for electrostatics  

NASA Astrophysics Data System (ADS)

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.

Fosco, César D.; Lombardo, Fernando C.; Mazzitelli, Francisco D.

2012-08-01

181

Proximal humeral fracture treatment in adults.  

PubMed

Most proximal humeral fractures affect elderly patients and can be treated nonoperatively with good functional outcomes.The treatment of displaced three and four-part fractures remains controversial and depends on a variety of underlying factors related to the patient (e.g., comorbidity, functional demand), the fracture (e.g., osteoporosis), and the surgeon (e.g., experience).Throughout the literature, open reduction and locking plate osteosynthesis is associated with considerable complication rates, particularly in the presence of osteoporosis.Low local bone mineral density, humeral head ischemia, residual varus displacement, insufficient restoration of the medial column, and nonanatomic reduction promote failure of fixation and impair functional outcome.The outcome of hemiarthroplasty is closely related to tuberosity healing in an anatomic position to enable the restoration of rotator cuff function. Reverse shoulder arthroplasty may provide satisfactory shoulder function in geriatric patients with preexisting rotator cuff dysfunction or after the failure of first-line treatment. PMID:24500588

Maier, Dirk; Jaeger, Martin; Izadpanah, Kaywan; Strohm, Peter C; Suedkamp, Norbert P

2014-02-01

182

[Ophthalmologists in the proximity of Adolf Hitler].  

PubMed

Adolf Hitler met or at least knew about 5 ophthalmologists. The chair of ophthalmology in Berlin, Walther Löhlein, 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

2012-10-01

183

Proximity to mining industry and cancer mortality.  

PubMed

Mining installations are releasing toxic substances into the environment which could pose a health problem to populations in their vicinity. We sought to investigate whether there might be excess cancer-related mortality in populations residing in towns lying in the vicinity of Spanish mining industries governed by the Integrated Pollution Prevention and Control Directive, and the European Pollutant Release and Transfer Register Regulation, according to the type of extraction method used. An ecologic study was designed to examine municipal mortality due to 32 types of cancer, across the period 1997 through 2006. Population exposure to pollution was estimated on the basis of distance from town of residence to pollution source. Poisson regression models, using the Bayesian conditional autoregressive model proposed by Besag, York and Molliè and Integrated Nested Laplace Approximations for Bayesian inference, were used: to analyze risk of dying from cancer in a 5-kilometer zone around mining installations; effect of type of industrial activity; and to conduct individual analyses within a 50-kilometer radius of each installation. Excess mortality (relative risk, 95% credible interval) of colorectal cancer (1.097, 1.041-1.157), lung cancer (1.066, 1.009-1.126) specifically related with proximity to opencast coal mining, bladder cancer (1.106, 1.016-1.203) and leukemia (1.093, 1.003-1.191) related with other opencast mining installations, was detected among the overall population in the vicinity of mining installations. Other tumors also associated in the stratified analysis by type of mine, were: thyroid, gallbladder and liver cancers (underground coal installations); brain cancer (opencast coal mining); stomach cancer (coal and other opencast mining installations); and myeloma (underground mining installations). The results suggested an association between risk of dying due to digestive, respiratory, hematologic and thyroid cancers and proximity to Spanish mining industries. These associations were dependent on the type of mine. PMID:22846765

Fernández-Navarro, Pablo; García-Pérez, Javier; Ramis, Rebeca; Boldo, Elena; López-Abente, Gonzalo

2012-10-01

184

Metabolic heterogeneity of the proximal and distal kidney tubules.  

PubMed

Proximal and distal tubule suspensions were prepared from kidneys of Sprague-Dawley rats by an isolation procedure on a Percoll gradient. The marker enzymes alkaline phosphatase (brush border) and hexokinase (cytoplasmic) as well as p-aminohippurate transport capacity, gluconeogenic activity and electron microscopy were used to characterize the two kidney tubule suspensions. The results of this study indicate that cytochrome P-450 is localized to the proximal tubular cells and that the O-deethylation of 7-ethoxycoumarin was higher in the proximal than distal fraction. Both proximal and distal tubules showed glucuronidation and deacetylation capacities and a relatively equal distribution of non-protein sulfhydryls. These studies demonstrate metabolic heterogeneity of the nephron, the proximal tubule being the main site of renal xenobiotic metabolism. Understanding of metabolic heterogeneity of proximal and distal kidney tubules should provide important information regarding cell specific mechanisms of nephrotoxicity. PMID:6604212

Cojocel, C; Maita, K; Pasino, D A; Kuo, C H; Hook, J B

1983-08-29

185

Best proximity point theorems generalizing the contraction principle  

Microsoft Academic Search

The primary objective of this article is to elicit some interesting extensions of the simple but powerful Banach’s contraction principle to the case of non-self-mappings. In fact, due to the fact that best proximity point theorems fit the bill to this end, the proposed extensions are presented as best proximity point theorems for non-self proximal contractions which are more general

S. Sadiq Basha

2011-01-01

186

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'Havé, Koen; Laenens, Bart; Vandenberghe, Geert; Cheng, Shaunee; Schreel, Koen; Gemmink, Jan-Willem

2011-03-01

187

Axial heterogeneity of sodium-bicarbonate cotransport in proximal straight tubule of rabbit kidney  

Microsoft Academic Search

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

1987-01-01

188

Red blood cell Na+/H+ and Li+/Na+ exchange in patients with essential hypertension.  

PubMed

The increased red blood cell Li+/Na+ exchange found in a subgroup of patients with essential hypertension (EH) may reflect an increased activity of the Na+/H+ exchange. The maximal velocity of the red cells' Na+/H+ (Na+ influx promoted by an outward H+ gradient) and Li+/Na+ (Li+ efflux promoted by external Na+) exchange were therefore measured in 41 EH and in 21 normotensive controls (NT). Both transporters were significantly higher in EH than in NT (74 +/- 39 mmol/L cell x h v 43 +/- 27 for the former, P less than .03, and 0.35 +/- 0.16 v 0.26 +/- 0.10 for the latter, P less than .05). Even though more than 100 times faster, Na+/H+ exchange was weakly but significantly correlated to Li+/Na+ exchange (r = 0.29, P less than .05). Proximal tubule Na+ reabsorption (fractional renal Li+ reabsorption) was significantly greater in EH than in NT (0.78 +/- 0.07, n = 32, v 0.73 +/- 0.06, n = 10, P less than .05) but it was not correlated to either the red cells' Na+/H+ or Li+/Na+ exchanges. Therefore, hyperactivity of Na+/H+ exchange in EH may play a role in blood pressure elevation through mechanisms other than stimulation of renal Na+ reabsorption. PMID:2558690

Semplicini, A; Canessa, M; Mozzato, M G; Ceolotto, G; Marzola, M; Buzzaccarini, F; Casolino, P; Pessina, A C

1989-12-01

189

Osteosarcoma of the proximal tibia: limb-sparing resection and reconstruction with a modular segmental proximal tibia tumor prosthesis.  

PubMed

A limb-sparing resection was performed for osteosarcoma of the proximal tibia in a young patient. A special modular segmental proximal tibial endoprosthesis that includes a hinged total knee component was used for reconstruction. A medial gastrocnemius rotational flap was utilized to reconstruct the extensor mechanism of the knee. The muscle flap aids in covering the prosthesis and helps to protect against infection. Limb-sparing resection for tumors arising from the proximal tibia, and reconstruction with a modular segmental proximal tibia tumor prosthesis and gastrocnemius muscle flap, is a safe and reliable method for treating tumors involving this area. PMID:20607421

Wittig, James C; Villalobos, Camilo E; Hayden, Brett L; Choi, Ikjoon; Silverman, Andrew M; Malawer, Martin

2010-11-01

190

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.

2009-01-01

191

Long proximal femoral nail in ipsilateral fractures proximal femur and shaft of femur  

PubMed Central

Background: Ipsilateral fractures of the proximal femur and femoral shaft are extremely uncommon injuries which occur in young adults who sustain a high energy trauma. A variety of management modalities have been tried to treat this complex fracture pattern ranging from conservative approach to recently introduced reconstruction nails. All these approaches have their own difficulties. We studied the outcome of long proximal femoral nail (LPFN) in the management of concomitant ipsilateral fracture of the proximal femur and femoral shaft. Materials and Methods: We analysed the prospective data of 36 consecutive patients who had sustained a high energy trauma (30 closed fractures and 6 open shaft fractures) who had concomitant ipsilateral fractures of the femoral shaft associated with proximal femur fractures treated with LPFN between December 2005 and December 2011. The mean age was 39 years (range 28-64 years). Twenty nine males and seven females were enrolled for this study. Results: The patients were followed up at three, six, twelve, and eighteen months. The mean healing time for the neck fractures was 4.8 months and for the shaft fractures was 6.2 months. The greater trochanter was splintered and widened in two cases which eventually consolidated. Two patients had superficial infection, two patients had lateral migration of the screws with coxa vara which was due to severe osteoporosis detected during the followup. We had two cases of nonunion of shaft fracture and one case of nonunion of neck fracture. Two cases of avascular necrosis of femoral head were detected after 2 years of followup. No cases of implant failure were noted. Limb shortening of less than 2 cms was noted in four of our patients. The functional assessment system of Friedman and Wyman was used for evaluating the results. In our series 59.9% (n = 23) were rated as good, 30.6% (n = 11) as fair, and 5.5% (n = 2) as poor. Conclusion: Long PFN is a reliable option for concomitant ipsilateral diaphyseal and proximal femur fractures.

Gadegone, WM; Lokhande, Vijayanand; Salphale, Yogesh; Ramteke, Alankar

2013-01-01

192

Particle Proximity Sensors for Suspension Flows  

NASA Astrophysics Data System (ADS)

A nonintrusive technique to indicate when noncolloidal particles suspended in a liquid are within a few microns of a solid surface---and therefore can interact with the surface---would be valuable in studying particle deposition and coating processes. We are developing such ``particle proximity sensors'' based upon calcium ion-specific fluorescent indicators, chemical compounds whose fluorescence is triggered by the presence of Ca^++. By coating a solid surface with zeolites that absorb Ca^++, particles dyed with these indicators suspended in a calcium ion-containing solution will stop fluorescing when they enter the Ca^++-depleted mass boundary layer next to this surface. Since these fluorescent indicators are developed for aqueous chemistries, an aqueous model suspension system was developed for non-colloidal PMMA particles (diameters 10--200 ?m) suspended in a liquid mixture of water, glycerine, and ammonium thiocyanate with a viscosity about five times that of water. This refractive-index matched, neutrally-buoyant suspension was characterized for a range of temperatures, volume fractions and chemical compositions. The intensity of fluorescence emitted from Ca^++ indicator-dyed PMMA particles near a zeolite-coated glass surface was measured as a function of distance normal to the surface at various zeolite thicknesses and flow speeds to determine the diffusion characteristics of this zeolite-Ca^++ system.

Bailey, Brent C.; Yoda, Minami

2001-11-01

193

Acidification in the rat proximal jejunum.  

PubMed Central

1. Production of hydrogen ions by the rat proximal jejunum was investigated using the everted sac technique. 2. Acidification occurred in the absence of glucose, increasing on addition of glucose to reach a maximal value. An apparent Km of 1-78 mM was derived for the glucose-dependent process. 3. Acidification in the presence of glucose was inhibited by 10 mM-2:4-dinitrophenol, 10 mM phlorrhizin, 10 mM aminophylline and anaerobiosis. 4. Histamine, ethylenediamine tetraacetic acid (EDTA), ouabain and acetazolamide, compounds known to alter acid production in gastric mucosa had no effect on jejunal acidification. 5. Galactose and 3-O-methylglucose failed to increase acidification; in contrast, mannose and fructose did lead to increases, indicating metabolic origin of the hydrogen ions. 6. Serosal and mucosal lactate production were measured and the calculated percentage of hydrogen ions possibly derived from this source was shown to account for only a small proportion of acidification. 7. The greatest increase in acidification with minimal simultaneous production of lactate occurred with ATP which was shown not to enter intestinal tissues. 8. A hypothesis for acidification, that of the break-down at the mucosal surface of ATP from intracellular metabolic sources, is proposed and its relevance to the postulated microclimate is discussed.

Blair, J A; Lucas, M L; Matty, A J

1975-01-01

194

Interactive orbital proximity operations planning system  

NASA Technical Reports Server (NTRS)

An interactive graphical proximity operations planning system was developed, which allows on-site design of efficient, complex, multiburn maneuvers in a dynamic multispacecraft environment. Maneuvering takes place in and out of the orbital plane. The difficulty in planning such missions results from the unusual and counterintuitive character of orbital dynamics and complex time-varying operational constraints. This difficulty is greatly overcome by visualizing the relative trajectories and the relevant constraints in an easily interpretable graphical format, which provides the operator with immediate feedback on design actions. The display shows a perspective bird's-eye view of a Space Station and co-orbiting spacecraft on the background of the Station's orbital plane. The operator has control over the two modes of operation: a viewing system mode, which enables the exporation of the spatial situation about the Space Station and thus the ability to choose and zoom in on areas of interest; and a trajectory design mode, which allows the interactive editing of a series of way points and maneuvering burns to obtain a trajectory that complies with all operational constraints. A first version of this display was completed. An experimental program is planned in which operators will carry out a series of design missions which vary in complexity and constraints.

Grunwald, Arthur J.; Ellis, Stephen R.

1988-01-01

195

Scintillation Proximity Assay of Arginine Methylation  

PubMed Central

Methylation of arginine residues, catalyzed by protein arginine methyltransferases (PRMTs), is one important protein post-translational 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, 3H-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.

Wu, Jiang; Xie, Nan; Feng, You; Zheng, Y. George

2011-01-01

196

Proximity-associated errors in contour metrology  

NASA Astrophysics Data System (ADS)

In contour metrology the CD-SEM (critical dimension scanning electron microscope) assigns a continuous boundary to extended features in an image. The boundary is typically assigned as a simple function of the signal intensity, for example by a brightness threshold or gradient. However, the neighborhood of different points along the feature boundary may vary considerably. Some parts of the boundary may have close neighboring features while others are relatively isolated. Neighboring features can obstruct the escape of secondary electrons. Varying proximity of neighbors therefore represents an influence on detected intensity. An intensity difference caused by a neighborhood difference can be incorrectly interpreted as a contour shift, for example when the contour passes from an isolated neighborhood to a dense one. The magnitude of this offset variation is estimated using images produced by JMONSEL, a Monte Carlo simulator of SEM secondary electron imaging, from simple model test patterns with varying neighborhoods. Similar structures were subsequently measured by both SEM and atomic force microscopy (AFM). Apparent shifts (i.e., errors) on the order of 0.5 nm to 1.0 nm for each edge were observed in both modeled and measured SEM images as compared to AFM when edge positions were assigned by using a fixed image brightness contour. Assignment of edges by brightness relative to the local background and local maximum brightness resulted in measurements that were less sensitive to neighborhood differences.

Villarrubia, John S.; Dixson, Ronald G.; Vladár, András E.

2010-03-01

197

Acute dislocation of the proximal tibiofibular joint.  

PubMed

The patient was a 19-year-old female who reported an acute onset of lateral left knee pain while participating in a 3-legged race. The patient reported to the emergency department immediately following the injury. Observation revealed prominence along the lateral aspect of the knee. The patient was unable to bear weight on her left lower extremity and her symptoms were exacerbated with extension of the knee. Although the initial radiographs of the left knee and lower leg showed no apparent fracture, a widening of the interosseous space between the tibia and the fibula and an altered position of the fibular head were noted on the anterior to posterior radiographic view. On the lateral radiographic view there was anterior displacement of the left fibula compared to the right. These radiographic findings suggested an anterolateral dislocation of the fibular head, the diagnosis of which was confirmed upon the completion of axial computed tomography. Successful closed reduction was achieved and the patient was treated with a period of protected weight bearing on crutches, progressing to full weight bearing over 6 weeks. At 1 year following the injury, the patient was participating in all regular activities of daily living without pain or instability. Early detection and immediate reduction of an acute dislocation of the proximal tibiofibular joint are important to prevent long-term disability. PMID:19881007

Hsieh, Chih-Hsin; Chen, Jian-Chih

2009-11-01

198

[Osteoporotic fractures of the proximal humerus].  

PubMed

Fractures of the proximal humerus are typical osteoporotic fractures of the elderly with an increasing incidence. Computed tomography (CT) with 3D reconstruction plays a more and more decisive role in the diagnostics because of an improved understanding of fractures in 3D images. The resulting correct fracture classification has significance for the decision of the best therapy procedure. Currently an extended version of the Codman classification with its four and more fragments is used to give additive information about varus or valgus dislocation, impression or distraction. The comparison of conservative and operative treatment showed no predominance of one of the procedures, therefore both strategies are justified. An operative treatment is recommended in complex fractures. Thus, early functional mobilization, early self-dependence and return to the activities of daily living are possible. Intramedullary nailing is advised in 2-part fractures, in dislocated multipart fractures locking plating or a primary reverse shoulder arthroplasty with refixation of the tuberosities in patients over 75 years. However, the improved plate and nail systems with polyaxiality, calcar screws, modern plate and nails designs as well as the possibility of arthroscopy-assisted nail implantation or plate removal combined with arthroscopic arthrolysis are innovative. PMID:23051983

Lill, H; Ellwein, A; Katthagen, C; Voigt, C

2012-10-01

199

Proximate industrial activity and psychological distress  

PubMed Central

This paper examines the role that gender, occupational status, and family status play in moderating the effect of industrial activity on the psychological well-being of nearby residents. Using a unique spatial assessment of industrial activity and an environmental risk/social stressor framework in conjunction with individual-level data from the Detroit Area Study (DAS) and demographic data from the U.S. census, we find that residents of neighborhoods in close proximity to industrial activity report elevated levels of psychological distress compared to residents of neighborhoods removed from this type of activity. These influences are more pronounced among women but gender differences are also contingent upon occupational and family statuses. We show that specific combinations of work and family statuses make persons particularly vulnerable to the influence of this environmental stressor and women are two and a half times more likely than men to have these vulnerable statuses. This study makes an important contribution to the environmental health literature because it reminds researchers of the fundamental influence of social roles when examining the link between environmental risks and mental health.

Downey, Liam; Jackson, James S.; Merrill, J. Bryce; Saint Onge, Jarron M.; Williams, David R.

2009-01-01

200

Ranging/tracking system for proximity operations  

NASA Astrophysics Data System (ADS)

The hardware development and testing phase of a hand held radar for the ranging and tracking for Shuttle proximity operations are considered. The radar is to measure range to a 3 sigma accuracy of 1 m (3.28 ft) to a maximum range of 1850 m (6000 ft) and velocity to a 3 sigma accuracy of 0.03 m/s (0.1 ft/s). Size and weight are similar to hand held radars, frequently seen in use by motorcycle police officers. Meeting these goals for a target in free space was very difficult to obtain in the testing program; however, at a range of approximately 700 m, the 3 sigma range error was found to be 0.96 m. It is felt that much of this error is due to clutter in the test environment. As an example of the velocity accuracy, at a range of 450 m, a 3 sigma velocity error of 0.02 m/s was measured. The principles of the radar and recommended changes to its design are given. Analyses performed in support of the design process, the actual circuit diagrams, and the software listing are included.

Nilsen, P.; Udalov, S.

1982-06-01

201

Interactive orbital proximity operations planning system  

NASA Technical Reports Server (NTRS)

An interactive, graphical proximity operations planning system was developed which allows on-site design of efficient, complex, multiburn maneuvers in the dynamic multispacecraft environment about the space station. Maneuvering takes place in, as well as out of, the orbital plane. The difficulty in planning such missions results from the unusual and counterintuitive character of relative orbital motion trajectories and complex operational constraints, which are both time varying and highly dependent on the mission scenario. This difficulty is greatly overcome by visualizing the relative trajectories and the relative constraints in an easily interpretable, graphical format, which provides the operator with immediate feedback on design actions. The display shows a perspective bird's-eye view of the space station and co-orbiting spacecraft on the background of the station's orbital plane. The operator has control over two modes of operation: (1) a viewing system mode, which enables him or her to explore the spatial situation about the space station and thus choose and frame in on areas of interest; and (2) a trajectory design mode, which allows the interactive editing of a series of way-points and maneuvering burns to obtain a trajectory which complies with all operational constraints. Through a graphical interactive process, the operator will continue to modify the trajectory design until all operational constraints are met. The effectiveness of this display format in complex trajectory design is presently being evaluated in an ongoing experimental program.

Grunwald, Arthur J.; Ellis, Stephen R.

1989-01-01

202

Scintillation proximity assay of arginine methylation.  

PubMed

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

2012-02-01

203

Gastric Fullness, Physical Activity, and Proximal Extent of Gastroesophageal Reflux  

Microsoft Academic Search

OBJECTIVES:Proximal extent of gastroesophageal reflux (PER) is relevant for symptoms in GERD patients. It has been suggested that PER is determined by the volume of the refluxate that, in turn, might depend on the degree of gastric fullness. Abdominal straining, during ambulation, increases the likelihood of gastroesophageal reflux. We assessed the influence of gastric fullness and ambulation on proximal extent

Sara Emerenziani; Xin Zhang; Kathleen Blondeau; Jiri Silny; Jan Tack; Jozef Janssens; Daniel Sifrim

2005-01-01

204

Fast direction-aware proximity for graph mining  

Microsoft Academic Search

In this paper we study asymmetric proximity measures on directed graphs, which quantify the relationships between two nodes or two groups of nodes. The measures are useful in several graph min- ing tasks, including clustering, link prediction and connection sub- graph discovery. Our proximity measure is based on the concept of escape probability. This way, we strive to summarize the

Hanghang Tong; Christos Faloutsos; Yehuda Koren

2007-01-01

205

Volar Plate Arthroplasty for Closed Proximal Interphalangeal Joint Injuries  

Microsoft Academic Search

The anatomy and histology of the volar plate at the proximal interphalangeal joint and the mechanism of fracture\\/subluxation of the base of the middle phalanx in closed proximal interphalangeal joint injuries is reviewed. Our current technique of repair for these injuries and its evolution from Eaton’s original procedure is described. The results of 71 cases of volar plate arthroplasty performed

G. DURHAM-SMITH; G. M. MCCARTEN

1992-01-01

206

Protein detection using proximity-dependent DNA ligation assays  

Microsoft Academic Search

The advent of in vitro DNA amplification has enabled rapid acquisition of genomic information. We present here an analogous technique for protein detection, in which the coordinated and proximal binding of a target protein by two DNA aptamers promotes ligation of oligonucleotides linked to each aptamer affinity probe . The ligation of two such proximity probes gives rise to an

Simon Fredriksson; Mats Gullberg; Jonas Jarvius; Charlotta Olsson; Kristian Pietras; Sigrún Margrét Gústafsdóttir; Arne Östman; Ulf Landegren

2002-01-01

207

Moral Education in the Zone of Proximal Development.  

ERIC Educational Resources Information Center

Outlines a Vygotskian perspective on moral development. Summarizes Lev Vygotsky's ideas about the "zone of proximal development" and extends them into the domain of moral education, focusing on an extract from the film, "Boyz 'n the Hood." Shows how the zone of proximal development facilitates moral development differently from contemporary…

Tappan, Mark B.

1998-01-01

208

Proximity-based access control for implantable medical devices  

Microsoft Academic Search

We proposea proximity-based access control scheme forimplantable medical devices (IMDs). Ourscheme is based onultrasonic distance- bounding and enables an implanted medical device to grant access to its resources only to those devices that are in its close proxim- ity. We demonstrate the feasibility of our approach through tests in an emulated patient environment. We show that, although im- planted, IMDs

Kasper Bonne Rasmussen; Claude Castelluccia; Thomas S. Heydt-benjamin; Srdjan Capkun

2009-01-01

209

The Spatial Evolution of Innovation Networks: A Proximity Perspective  

Microsoft Academic Search

We propose an evolutionary perspective on the geography of network formation that is grounded in a dynamic proximity framework. In doing so, we root the proximity concept in an evolutionary approach to the geography of innovation networks. We discuss three topics. The first topic focuses on explaining the structure of networks. The second topic concentrates on explaining the effects of

Ron Boschma; Koen Frenken

2009-01-01

210

Anatomic reconstruction of chronic symptomatic anterolateral proximal tibiofibular joint instability.  

PubMed

Symptomatic chronic proximal tibiofibular joint subluxation is a pathology which is difficult to diagnose and treat. Surgical treatment has not been well defined. A report of two patients successfully treated with an anatomic reconstruction of the posterior aspect of the proximal tibiofibular joint is presented. PMID:20127312

Horst, Patrick K; LaPrade, Robert F

2010-11-01

211

Cytokine detection by antibody-based proximity ligation  

Microsoft Academic Search

Efficient and precise detection techniques, along with extensive repertoires of specific binding reagents, will be needed to meet the challenges of proteome analyses. The recently established proximity ligation mechanism enables sensitive high-capacity protein measurements by converting the detection of specific proteins to the analysis of DNA sequences. Proximity probes containing oligonucleotide extensions are designed to bind pairwise to target proteins

Mats Gullberg; Sigrún M. Gústafsdóttir; Edith Schallmeiner; Jonas Jarvius; Mattias Bjarnegård; Christer Betsholtz; Ulf Landegren; Simon Fredriksson

2004-01-01

212

Proximity and territory versus space in regional science  

Microsoft Academic Search

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

1996-01-01

213

Multipoint-based tabu search using proximate optimality principle  

Microsoft Academic Search

This paper presents a new method for combinatorial optimization problems. Most of the actual problems that have discrete structure can be formulated as combinatorial optimization problems. It is experientially known that proximate optimality principle (POP) holds in most of the actual combinatorial optimization problems. The concept of proximate optimality principle says that good solutions of most real combinatorial optimization problems

Keisuke Miyamoto; Keiichiro Yasuda

2005-01-01

214

Spot image processing and simulation of the laser proximity fuze  

Microsoft Academic Search

This paper investigates the problems of the large beam divergence angle and short detection range in the launch system of laser proximity fuze. By analyzing the factors of measuring distance in laser proximity fuze, combined with characteristics of laser's far-field divergence angle, and according to aspheric optical design theory, we carry out image processing and simulation of laser spot by

Lin Gan; He Zhang; Xiang-jin Zhang

2011-01-01

215

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

2013-03-01

216

Dual pathology proximal median nerve compression of the forearm.  

PubMed

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. 3) 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

2013-12-01

217

Proximal gastrectomy with jejunal interposition and TGRY anastomosis for proximal gastric cancer  

PubMed Central

AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY). METHODS: From January 2009 to January 2011, thirty-five patients underwent PGJI, and forty-one patients underwent TGRY. The surgical efficacy and short-term follow-up outcomes were compared between the two groups. RESULTS: There were no differences in the demographic and clinicopathological characteristics. The mean operation duration and postoperative hospital stay in the PGJI group were statistically longer than those in the TGRY group (P = 0.00). No anastomosis leakage was observed in two groups. No statistically significant difference was found in endoscopic findings, Visick grade or serum albumin level. The single-meal food intake in the PGJI group was more than that in the TGRY group (P = 0.00). The PG group showed significantly better hemoglobin levels in the second year (P = 0.02). The two-year survival rate was not significantly different (PGJI vs TGRY, 93.55% vs 92.5%, P = 1.0). CONCLUSION: PGJI is a safe, radical surgical method for proximal gastric cancer and leads to better outcomes in terms of the single-meal food intake and hemoglobin level, compared with TGRY in the short term.

Zhao, Ping; Xiao, Shuo-Meng; Tang, Ling-Chao; Ding, Zhi; Zhou, Xiang; Chen, Xiao-Dong

2014-01-01

218

Control of Proximal Bicarbonate Reabsorption in Normal and Acidotic Rats  

PubMed Central

This free-flow micropuncture study examined the dependence of bicarbonate reabsorption in the rat superficial proximal convoluted tubule to changes in filtered bicarbonate load, and thereby the contribution of the proximal tubule to the whole kidney's response to such changes. The independent effects of extracellular fluid (ECF) volume expansion and of acidosis on proximal bicarbonate reabsorption were also examined. When the plasma volume contraction incurred by the micropuncture preparatory surgery was corrected by isoncotic plasma infusion (?1.3% body wt), single nephron glomerular filtration rate (SNGFR), and the filtered total CO2 load increased by 50%. Absolute proximal reabsorption of total CO2 (measured by microcalorimetry) increased by 30%, from 808±47 during volume contraction to 1,081±57 pmol/min·g kidney wt after plasma repletion, as fractional total CO2 reabsorption decreased from 0.90 to 0.77. Aortic constriction in these plasma-repleted rats returned the filtered load and reabsorption of total CO2 to the previous volume contracted levels. In other animals isohydric ECF expansion with plasma (5% body wt) or Ringer's solution (10% body wt), or both, produced no further diminution in fractional proximal total CO2 reabsorption (0.76-0.81). Metabolic acidosis was associated with very high fractional proximal total CO2 reabsorptive rates of 0.82 to 0.91 over a wide range of SNGFR and ECF volumes. At a single level of SNGFR, end-proximal total CO2 concentration progressively decreased from 5.6±0.5 to 1.6 ±0.2 mM as arterial pH fell from 7.4 to 7.1. Expansion of ECF volume in the acidotic rats did not inhibit the ability of the proximal tubule to lower end-proximal total CO2 concentrations to minimal levels. In conclusion, bicarbonate reabsorption in the superficial proximal convoluted tubule is highly load-dependent (75-90%) in normal and acidotic rats. No inhibitory effect of ECF volume per se on proximal bicarbonate reabsorption, independent of altering the filtered bicarbonate load, could be discerned. Acidosis enabled the end-proximal luminal bicarbonate concentration to fall below normal values and reduced distal bicarbonate delivery.

Cogan, Martin G.; Maddox, David A.; Lucci, Marjory S.; Rector, Floyd C.; Mueller, Monika R.; Wong, Kenneth R.

1979-01-01

219

Protein detection using proximity-dependent DNA ligation assays.  

PubMed

The advent of in vitro DNA amplification has enabled rapid acquisition of genomic information. We present here an analogous technique for protein detection, in which the coordinated and proximal binding of a target protein by two DNA aptamers promotes ligation of oligonucleotides linked to each aptamer affinity probe. The ligation of two such proximity probes gives rise to an amplifiable DNA sequence that reflects the identity and amount of the target protein. This proximity ligation assay detects zeptomole (40 x 10(-21) mol) amounts of the cytokine platelet-derived growth factor (PDGF) without washes or separations, and the mechanism can be generalized to other forms of protein analysis. PMID:11981560

Fredriksson, Simon; Gullberg, Mats; Jarvius, Jonas; Olsson, Charlotta; Pietras, Kristian; Gústafsdóttir, Sigrún Margrét; Ostman, Arne; Landegren, Ulf

2002-05-01

220

Proximal caries detection: Sirona Sidexis versus Kodak Ektaspeed Plus.  

PubMed

This study compared the accuracy of intraoral film and a charge-coupled device (CCD) receptor for proximal caries detection. Four observers evaluated images of the proximal surfaces of 40 extracted posterior teeth. The presence or absence of caries was scored using a five-point confidence scale. The actual status of each surface was determined from ground section histology. Responses were evaluated by means of receiver operating characteristic (ROC) analysis. Areas under ROC curves (Az) were assessed through a paired t-test. The performance of the CCD-based intraoral sensor was not different statistically from Ektaspeed Plus film in detecting proximal caries. PMID:15779222

Khan, Emad A; Tyndall, Donald A; Ludlow, John B; Caplan, Daniel

2005-01-01

221

Control of proximal bicarbonate reabsorption in normal and acidotic rats.  

PubMed

This free-flow micropuncture study examined the dependence of bicarbonate reabsorption in the rat superficial proximal convoluted tubule to changes in filtered bicarbonate load, and thereby the contribution of the proximal tubule to the whole kidney's response to such changes. The independent effects of extracellular fluid (ECF) volume expansion and of acidosis on proximal bicarbonate reabsorption were also examined. When the plasma volume contraction incurred by the micropuncture preparatory surgery was corrected by isoncotic plasma infusion ( congruent with1.3% body wt), single nephron glomerular filtration rate (SNGFR), and the filtered total CO(2) load increased by 50%. Absolute proximal reabsorption of total CO(2) (measured by microcalorimetry) increased by 30%, from 808+/-47 during volume contraction to 1,081+/-57 pmol/min.g kidney wt after plasma repletion, as fractional total CO(2) reabsorption decreased from 0.90 to 0.77. Aortic constriction in these plasma-repleted rats returned the filtered load and reabsorption of total CO(2) to the previous volume contracted levels. In other animals isohydric ECF expansion with plasma (5% body wt) or Ringer's solution (10% body wt), or both, produced no further diminution in fractional proximal total CO(2) reabsorption (0.76-0.81). Metabolic acidosis was associated with very high fractional proximal total CO(2) reabsorptive rates of 0.82 to 0.91 over a wide range of SNGFR and ECF volumes. At a single level of SNGFR, end-proximal total CO(2) concentration progressively decreased from 5.6+/-0.5 to 1.6 +/-0.2 mM as arterial pH fell from 7.4 to 7.1. Expansion of ECF volume in the acidotic rats did not inhibit the ability of the proximal tubule to lower end-proximal total CO(2) concentrations to minimal levels. In conclusion, bicarbonate reabsorption in the superficial proximal convoluted tubule is highly load-dependent (75-90%) in normal and acidotic rats. No inhibitory effect of ECF volume per se on proximal bicarbonate reabsorption, independent of altering the filtered bicarbonate load, could be discerned. Acidosis enabled the end-proximal luminal bicarbonate concentration to fall below normal values and reduced distal bicarbonate delivery. PMID:500804

Cogan, M G; Maddox, D A; Lucci, M S; Rector, F C

1979-11-01

222

Functional characterization of SDF-1 proximal promoter.  

PubMed

Stromal-cell derived factor 1 (SDF1) is a CXC chemokine that binds and signals through the CXCR4 receptor, playing an essential role in embryonic B lymphopoiesis, myelopoiesis and organogenesis. The CXCR4/SDF1 pathway is associated with several pathologies. CXCR4 serves as a fusion cofactor for lymphotropic strains of human immunodeficiency virus type 1 and SDF1 inhibits viral entry. Moreover, recent works suggest an important role for SDF1 in metastasis progression and autoimmune diseases such as rheumatoid arthritis. To understand the molecular mechanisms that regulate SDF1 expression, we have cloned and functionally analysed its 5' flanking regulatory region. An SDF1-promoter luciferase construct showed high levels of reporter gene activity in transient transfection experiments. DNase I footprinting analysis revealed that the proximal promoter was occupied by six putative Sp1-binding motifs. Binding of Sp1 to the promoter was confirmed by electrophoretic mobility shift assay, and its importance in SDF1 gene expression verified by in vitro mutagenesis. Particularly, mutation of an Sp1 motif located between -57 and -39 upstream of the main transcription start-site resulted in a marked reduction in promoter activity. It has been shown that the SDF1 expression could be induced by mitogenic stimuli, X-ray radiation or treatment with IL1beta, depending on cell environment. We have analysed the effect of these stimuli on SDF1 promoter transactivation in three different cell lines. Phorbol myristated acetate plus ionomycin increased promoter activity in U373 and LC5 but repressed it in MS5 cells. On the contrary, gamma irradiation promoted SDF1 transcription in MS5 cells but not in the other cell lines. Interferon-gamma acted as a transcriptional repressor in U373 and LC5 but not in MS5 cells. Finally, IL1beta functions as mild activator only in U373 cells. The present study demonstrates that these stimuli mediate SDF1 production through promoter activation in a cell-specific manner. PMID:15808852

García-Moruja, Carelia; Alonso-Lobo, Juan M; Rueda, Patricia; Torres, Carmen; González, Nuria; Bermejo, Mercedes; Luque, Francisco; Arenzana-Seisdedos, Fernando; Alcamí, José; Caruz, Antonio

2005-04-22

223

Proximity to Urban Parks and Mental Health  

PubMed Central

Background Urban parks have received attention in recent years as a possible environmental factor that could encourage physical activity, prevent obesity, and reduce the incidence of chronic conditions. Despite long hypothesized benefits of parks for mental health, few park studies incorporate mental health measures. Aims of the Study To test the association between proximity to urban parks and psychological distress. Methods Cross-sectional analysis of individual health survey responses. Data were collected for a study of capital improvements of neighborhood parks in Los Angeles. A survey was fielded on a sample of residential addresses, stratified by distance from the park (within 400m, 800m, 1.6 km, and 3.2km; N=1070). We used multiple regression to estimate the relationship between the psychological distress as measured by the MHI-5 (outcome variable) and distance to parks (main explanatory variable), controlling for observed individual characteristics. Results Mental health is significantly related to residential distance from parks, with the highest MHI-5 scores among residents within short walking distance from the park (400m) and decreasing significantly over the next distances. The number of visits and physical activity minutes are significantly and independently related to distance, although controlling for them does not reduce the association between distance and mental health. Discussion and Limitations This paper provides a new data point for an arguably very old question, but for which empirical data are sparse for the US. A nearby urban park is associated with the same mental health benefits as decreasing local unemployment rates by 2 percentage points, suggesting at least the potential of environmental interventions to improve mental health. The analysis is cross-sectional, making it impossible to control for important confounders, including residential selection. Implications for Health Policy Mental health policy has traditionally focused on individual-centered interventions. Just as health policy for preventable chronic illnesses has shifted attention to modifiable environmental determinants, population mental health may benefit substantially from environmental interventions. Implications for Future Research Policy evaluations should incorporate mental health measures when assessing neighborhood improvement programs and physical environments. Many recent and ongoing studies have excluded mental health measure in the belief that they are too burdensome for respondents or irrelevant. If a causal relationship is confirmed, then ameliorating neighborhood conditions and physical environments could represent a scalable way to improve mental health issues for large populations.

Sturm, Roland; Cohen, Deborah

2014-01-01

224

Na+-sulfate cotransporter SLC13A1.  

PubMed

Sulfate is essential for normal physiology. The kidney plays a major role in sulfate homeostasis. Sulfate is freely filtered and strongly reabsorbed in the proximal tubule. The apical membrane Na(+)-sulfate cotransporter NaS1 (SLC13A1) mediates sulfate (re)absorption across renal proximal tubule and small intestinal epithelia. NaS1 encodes a 595-amino acid (? 66 kDa) protein with 13 putative transmembrane domains. Its substrate preferences are sodium and sulfate, thiosulfate, and selenate, and its activity is inhibited by molybdate, selenate, tungstate, thiosulfate, succinate, and citrate. NaS1 is primarily expressed in the kidney (proximal tubule) and intestine (duodenum to colon). NaS1 expression is down-regulated in the renal cortex by high sulfate diet, hypothyroidism, vitamin D depletion, glucocorticoids, hypokalemia, metabolic acidosis, and NSAIDs and up-regulated by low sulfate diet, thyroid hormone, vitamin D supplementation, growth hormone, chronic renal failure, and during post-natal growth. Disruption of murine NaS1 gene leads to hyposulfatemia and hypersulfaturia, as well as changes in metabolism, growth, fecundity, behavior, gut physiology, and liver detoxification. This suggests that NaS1 is an important sulfate transporter and its disruption leads to perturbed sulfate homeostasis, which contributes to numerous pathophysiological conditions. PMID:24193406

Markovich, Daniel

2014-01-01

225

Proportional proximity sensing for telerobots using Coherent Laser Radar  

NASA Technical Reports Server (NTRS)

The ability of a telerobotic manipulator to operate in confined spaces while avoiding unwanted collisions is enhanced by the accurate sensing of its proximate environment. To achieve the fidelity required for precise manipulator control, a proportional proximity sensor system with a sufficiently large measurement envelope is required. Current proximity sensors provide a binary indication of the presence of obstacles within a small envelope with coarse or no proportional measurement of their location. A proportional proximity sensor system configured as a Frequency Modulated Continuous Wave (FMCW) Coherent Laser Radar (CLR) using a semiconductor laser as the energy source is described and analyzed. The source and reflected energies mix coherently to generate a radio frequency (RF) signal whose frequency is proportional to the range. The system is tested for accuracy, range, depth of range, speed, and sensitivity and the results are presented. Techniques to derive orientation information and an application to telerobotic control are also described.

Vazquez, Sixto L.; Goode, Plesent W.; Slotwinski, Anthony R.

1992-01-01

226

Challenger's RMS arm grasps SPAS-01 during proximity operations  

NASA Technical Reports Server (NTRS)

Challenger's remote manipulator system (RMS) arm grasps Shuttle pallet satellite (SPAS-01) during proximity operations. The frame shows a number of reflections on the window, located overhead in the aft flight deck.

1983-01-01

227

Alternative Power-Line Proximity-Warning Techniques.  

National Technical Information Service (NTIS)

The performance requirements for a powerline proximity-warning (PLPW) system include high probability of detection at a dependable alarm range, low probability of false alarm, no setup or calibration, and little maintenance or adjustment. These requiremen...

F. H. Raab

1982-01-01

228

Proximal Corpus Cavernosum Tear Presenting as Scrotal Hematoma  

PubMed Central

We present the case of a penile fracture involving the proximal corpus cavernosum, presenting as a hematoma extending into the scrotum. The presentation, diagnosis, and surgical approach, which differ from the more typical penile shaft fracture, are delineated.

Darves-Bornoz, A.; DeBartolo, M. M.; Mishail, A. M.

2013-01-01

229

View to northeast, showing west elevation and south side. Proximity ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View to northeast, showing west elevation and south side. Proximity of fence of adjacent subdivision precluded photography of north side. - Drew-Sherwood Farm, Barn, 7927 Elk Grove Boulevard, Elk Grove, Sacramento County, CA

230

Adjusting proximity thresholds for activating a device user interface  

US Patent & Trademark Office Database

A thermostat includes a user interface that is configured to operate in at least two different modes including a first mode and a second mode. The user interface may require more power when operating in the first mode than in the second mode. The thermostat also includes a plurality of sensors, including at least one sensor configured to detect a presence of a user within a proximity of the thermostat. The thermostat additionally includes a first processing function that is configured to determine a proximity profile and to cause the user interface to be in the first mode one or more sensors provides responses that match the proximity profile. The proximity profile may be computed using a history of responses from the sensors that are likely to coincide with times where users intend to view the user interface.

2013-10-15

231

Deleting the TGF-? Receptor Attenuates Acute Proximal Tubule Injury  

PubMed Central

TGF-? is a profibrotic growth factor in CKD, but its role in modulating the kidney’s 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.

Vadivelu, Sangeetha; Neelisetty, Surekha; Srichai, Manakan B.; Paueksakon, Paisit; Pozzi, Ambra; Harris, Raymond C.

2012-01-01

232

Technical tips: Dualplate fixation technique for comminuted proximal humerus fractures.  

PubMed

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

2014-08-01

233

Permanent anterior dislocation of the proximal tibiofibular joint.  

PubMed

We report two patients with permanent dislocation of the proximal tibiofibular joint and no history of trauma. Both needed operation, one for persistent pain and the other for common peroneal nerve involvement, and both had a good result. PMID:2925742

Molitor, P J; Dandy, D J

1989-03-01

234

Provider proximity as a predictor of referral rate and success.  

PubMed

The predictive utility of proximity of primary care providers (PCPs) to mental health providers (MHPs) in referral rate and referral success was examined. Referrals from all PCPs in three New Jersey primary care clinics with primary care mental health integration (PC-MHI) to MHPs for fiscal year 2009 (October 1, 2008 through September 30, 2009) were included. Regression analyses supported the hypotheses that proximity significantly predicts both rate of referral per visit and rate of referral per unique patient. The hypothesis that proximity predicts referral success was not supported. Further research might seek to determine if additional variables moderate the relationship between provider proximity and referral rate. Implications of the findings for colocated programs were discussed. PMID:22984880

Calkins, Lauri E; Michelson, Ilysa R; Corso, Andrew S

2013-11-01

235

Embedded System Implementation of Sound Localization in Proximal Region  

NASA Astrophysics Data System (ADS)

A sound localization method in the proximal region is proposed, which is based on a low-cost 3D sound localization algorithm with the use of head-related transfer functions (HRTFs). The auditory parallax model is applied to the current algorithm so that more accurate HRTFs can be used for sound localization in the proximal region. In addition, head-shadowing effects based on rigid-sphere model are reproduced in the proximal region by means of a second-order IIR filter. A subjective listening test demonstrates the effectiveness of the proposed method. Embedded system implementation of the proposed method is also described claiming that the proposed method improves sound effects in the proximal region only with 5.1% increase of memory capacity and 8.3% of computational costs.

Iwanaga, Nobuyuki; Matsumura, Tomoya; Yoshida, Akihiro; Kobayashi, Wataru; Onoye, Takao

236

Interactive Orbital Proximity Operations Planning System. (Abstract Only).  

National Technical Information Service (NTIS)

An interactive graphical planning system for on-site planning of proximity operations in the congested multispacecraft environment about the space station is presented. The system shows the astronaut a bird's eye perspective of the space station, the orbi...

A. J. Grunwald, S. R. Ellis

1990-01-01

237

Light-operated proximity detector with linear output  

DOEpatents

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 phtotransistor 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, M.L.; McNeilly, D.R.

1984-01-01

238

Analysis on the characteristics of pulsed laser proximity fuze's echo  

NASA Astrophysics Data System (ADS)

With the rapid development of semiconductor technology and laser technology, a kind of proximity fuze named pulsed laser proximity fuze has been applied. Compared with other fuzes, pulsed laser proximity fuze has high ranging precision and strong resistance to artificial active interference. It is an important development tendency of proximity fuze. The paper analyze the characteristic of target echo of laser signal, and then make theoretical analysis and calculation on the laser signal transmission in the smog. Firstly, use the pulse width of 10ns semiconductor laser fuze to do typical targets experiment, to get the echo information of target distance is 5m; then to do smog interference experiment, by comparing the pulse width amplitude and backscattering signal amplitude of laser fuze in simulation and experiment, analyzing the effect of anti-clutter, providing the evidence for the subsequent of circuit of signal amplification and processing.

Wang, Kun; Chen, Huimin

2011-06-01

239

76 FR 70075 - Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines  

Federal Register 2010, 2011, 2012, 2013

...Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines AGENCY...Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines. This...Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines....

2011-11-10

240

76 FR 63238 - Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines  

Federal Register 2010, 2011, 2012, 2013

...Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines AGENCY...Proximity Detection Systems for Continuous Mining Machines in Underground Coal Mines, published...Proximity Detection Systems on Continuous Mining Machines in Underground Coal Mines....

2011-10-12

241

Noncontact Respiration Rate Measurement System Using an Ultrasonic Proximity Sensor  

Microsoft Academic Search

This research presents the ultrasonic proximity sensor approach to respiration measurement. The ultrasonic proximity sensor measures respiration signatures and rates in real-time and for long-term monitoring, which is necessary for mobility from the end-user perspective. The study used a 240 kHz ultrasonic sensor to measure the time of flight of a sound wave between the transmitted signal and received signal

Se Dong Min; Jin Kwon Kim; Hang Sik Shin; Yong Hyeon Yun; Chung Keun Lee; Myoungho Lee

2010-01-01

242

Proximate time-optimal control of third-order servomechanisms  

Microsoft Academic Search

The problem of proximate time-optimal control of third-order systems is considered. Two proximate time-optimal servomechanisms, PTO53 and PTO53?, are proposed for type-3 and type-2 third-order plants, respectively. Theorems stating sufficient conditions on each system's control design parameters to ensure global stability are given, and it is shown that the control parameters can be adjusted to accommodate, more or less, disturbances

L. Y. Pao; G. F. Franklin

1993-01-01

243

Hemiarthroplasty for proximal humeral fracture: restoration of the Gothic arch.  

PubMed

Proximal humerus fractures are the most common fractures of the shoulder girdle, and initial management of these injuries often determines final outcome. When arthroplasty is used to manage proximal humeral fractures, surgery remains technically demanding, and outcomes have been unpredictable. Recent advances in both technique and prosthetic implants have led to more successful and reproducible results. Key technical points include restoration of the Gothic arch, anatomic tuberosity reconstruction, and minimal soft tissue dissection. PMID:18803974

Krishnan, Sumant G; Bennion, Phillip W; Reineck, John R; Burkhead, Wayne Z

2008-10-01

244

The Complexity of Self-Regular Proximity Based Infeasible IPMs  

Microsoft Academic Search

Primal-Dual Interior-Point Methods (IPMs) have shown their power in solving large classes of optimization problems. In this\\u000a paper a self-regular proximity based Infeasible Interior Point Method (IIPM) is proposed for linear optimization problems.\\u000a First we mention some interesting properties of a specific self-regular proximity function, studied recently by Peng and Terlaky,\\u000a and use it to define infeasible neighborhoods. These simple

Maziar Salahi; Tamás Terlaky; Guoqing Zhang

2006-01-01

245

VCSEL-based microsensors for photonic proximity fuzing of munitions  

Microsoft Academic Search

This paper describes technologies developed at Sandia National Laboratories to support a joint DoD\\/DoE initiative to create a compact, robust, and affordable photonic proximity sensor for munitions fuzing. The proximity fuze employs high-power vertical-cavity surface-emitting laser (VCSEL) arrays, resonant-cavity photodetectors (RCPDs), and refractive micro-optics that are integrated within a microsensor whose volume is approximately 0.01 cm3. Successful development and integration

G. A. Keeler; A. Mar; K. M. Geib; A. Y. Hsu; D. K. Serkland; G. M. Peake

2008-01-01

246

Proximal dome-shaped osteotomy for symptomatic bunionette.  

PubMed

The results of a dome-shaped osteotomy of the proximal third of the fifth metatarsal in patients with symptomatic bunionette deformity were reviewed. The series was comprised of eight patients (10 feet; mean age of patients, 21 years). The average followup was 30 months. All patients were free from pain at the fifth metatarsophalangeal joint and were satisfied with the results of this procedure. The mean angle between the longitudinal axes of the fifth metatarsal and the proximal phalanx was 18.9 degrees before surgery and 2.6 degrees after surgery. The mean angle between the longitudinal axes of the fourth and fifth metatarsals was 12.2 degrees before surgery and 4.8 degrees after surgery. The overall results were good in all 10 feet. Three feet had delayed union at the osteotomy site, but union was obtained in all feet. The osteotomy site of the fifth metatarsal in feet with delayed union was more proximal than that of the other feet. Therefore, proximal osteotomy of the fifth metatarsal should be done not at the base, but at the proximal site of the diaphysis to prevent delayed union. A proximal dome-shaped osteotomy corrects the deformity and relieves the symptoms, but careful attention should be paid to the osteotomy site. PMID:11859240

Okuda, Ryuzo; Kinoshita, Mitsuo; Morikawa, Junichi; Jotoku, Tsuyoshi; Abe, Muneaki

2002-03-01

247

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

2011-02-01

248

Regulation of an Inwardly Rectifying ATP-sensitive K+ Channel in the Basolateral Membrane of Renal Proximal Tubule  

PubMed Central

Functional coupling of Na+,K+-ATPase pump activity to a basolateral membrane (BLM) K+ conductance is crucial for sustaining transport in the proximal tubule. Apical sodium entry stimulates pump activity, lowering cytosolic [ATP], which in turn disinhibits ATP-sensitive K+ (KATP) channels. Opening of these KATP channels mediates hyperpolarization of the BLM that facilitates Na+ reabsorption and K+ recycling required for continued Na+,K+-ATPase pump turnover. Despite its physiological importance, little is known about the regulation of this channel. The present study focuses on the regulation of the BLM KATP channel by second messengers and protein kinases using membrane patches from dissociated, polarized Ambystoma proximal tubule cells. The channel is regulated by protein kinases A and C, but in opposing directions. The channel is activated by forskolin in cell-attached (c/a) patches, and by PKA in inside-out (i/o) membrane patches. However, phosphorylation by PKA is not sufficient to prevent channel rundown. In contrast, the channel is inhibited by phorbol ester in c/a patches, and PKC decreases channel activity (nPo) in i/o patches. The channel is pH sensitive, and lowering cytosolic pH reduces nPo. Increasing intracellular [Ca2+] ([Ca2+]i) in c/a patches decreases nPo, and this effect is direct since [Ca2+]i inhibits nPo with a Ki of ?170 nM in i/o patches. Membrane stretch and hypotonic swelling do not significantly affect channel behavior, but the channel appears to be regulated by the actin cytoskeleton. Finally, the activity of this BLM KATP channel is coupled to transcellular transport. In c/a patches, maneuvers that inhibit turnover of the Na+,K+-ATPase pump reduce nPo, presumably due to a rise in intracellular [ATP], although the associated cell depolarization cannot be ruled out as the possible cause. Conversely, stimulation of transport (and thus pump turnover) leads to increases in nPo, presumably due to a fall in intracellular [ATP]. These results show that the inwardly rectifying KATP channel in the BLM of the proximal tubule is a key element in the feedback system that links cellular metabolism with transport activity. We conclude that coupling of this KATP channel to the activity of the Na+,K+-ATPase pump is a mechanism by which steady state NaCl reabsorption in the proximal tubule may be maintained.

Mauerer, Ulrich R.; Boulpaep, Emile L.; Segal, Alan S.

1998-01-01

249

Oral sodium bicarbonate reduces proximal renal tubular peptide catabolism, ammoniogenesis, and tubular damage in renal patients.  

PubMed

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

1998-03-01

250

Sodium-coupled Taurocholate Transport in the Proximal Convolution of the Rat Kidney In Vivo and In Vitro  

PubMed Central

Using the standing droplet technique in the renal proximal convolution and simultaneous microperfusion of the peritubular capillaries, the zero net flux transtubular concentration difference of taurocholate (?CTC?) at 45 s was determined as a measure of active bile acid reabsorption in vivo. Starting with 0.1 mmol/liter taurocholate in both perfusates the control ?CTC? of 0.042 mmol/liter fell to 0.006 mmol/liter (P < 0.001) when the Na+ concentration in the perfusates was reduced to zero. Removal of bicarbonate from the perfusates to alter pH had no influence on ?CTC?. When glycocholate was added to the perfusates ?CTC? was decreased, while probenecid increased ?CTC?. These observations were extended by studies performed with brush border membrane vesicles derived from renal cortex. The initial (20 s) uptake of 0.01 mmol/liter taurocholate in the presence of a Nao+ > Nai+ gradient was stimulated twofold compared with its uptake in the absence of a Na+ gradient. Uptake of taurocholate was osmotically and temperature sensitive. Membranes preloaded with unlabeled glycocholate showed accelerated entry of labeled taurocholate (trans-stimulation) only in the presence of Na+. Replacement of Na+ in the media with K+, Li+, and choline+ decreased initial taurocholate uptake by 49, 53, and 62%, respectively. Stimulation of taurocholate transport by cation gradient diffusion potentials was unlikely inasmuch as the addition of valinomycin under K+ gradient conditions had no effect. A transmembrane pH gradient (pHo < pHi) did not influence initial uptake of taurocholate. Finally, in the presence of Na+ taurocholate transport showed cis-inhibition with unlabeled bile acids and saturation kinetics with respect to increasing taurocholate concentrations. The micropuncture and vesicle data indicate that the net transport of taurocholate in the proximal tubule is the result of an electroneutral Na+-taurocholate cotransport across the brush border membrane.

Wilson, Frederick A.; Burckhardt, Gerhard; Murer, Heini; Rumrich, Gerhard; Ullrich, Karl J.

1981-01-01

251

Cytokine detection by antibody-based proximity ligation.  

PubMed

Efficient and precise detection techniques, along with extensive repertoires of specific binding reagents, will be needed to meet the challenges of proteome analyses. The recently established proximity ligation mechanism enables sensitive high-capacity protein measurements by converting the detection of specific proteins to the analysis of DNA sequences. Proximity probes containing oligonucleotide extensions are designed to bind pairwise to target proteins and to form amplifiable tag sequences by ligation when brought in proximity. In our previous report, both the ligatable arms and the protein binders were DNA molecules. We now generalize the method by providing simple and convenient protocols to convert any polyclonal antibodies or matched pair of monoclonal antibodies to proximity probe sets through the attachment of oligonucleotide sequences. Sufficient reagent for >100,000 proximity ligation assays can be prepared from 1 microg of antibody. The technique is applied to measure cytokines in a homogenous test format with femtomolar detection sensitivities in 1-microl samples, and we exemplify its utility in situations when only minute sample amounts are available. PMID:15155907

Gullberg, Mats; Gústafsdóttir, Sigrún M; Schallmeiner, Edith; Jarvius, Jonas; Bjarnegård, Mattias; Betsholtz, Christer; Landegren, Ulf; Fredriksson, Simon

2004-06-01

252

Cytokine detection by antibody-based proximity ligation  

PubMed Central

Efficient and precise detection techniques, along with extensive repertoires of specific binding reagents, will be needed to meet the challenges of proteome analyses. The recently established proximity ligation mechanism enables sensitive high-capacity protein measurements by converting the detection of specific proteins to the analysis of DNA sequences. Proximity probes containing oligonucleotide extensions are designed to bind pairwise to target proteins and to form amplifiable tag sequences by ligation when brought in proximity. In our previous report, both the ligatable arms and the protein binders were DNA molecules. We now generalize the method by providing simple and convenient protocols to convert any polyclonal antibodies or matched pair of monoclonal antibodies to proximity probe sets through the attachment of oligonucleotide sequences. Sufficient reagent for >100,000 proximity ligation assays can be prepared from 1 ?g of antibody. The technique is applied to measure cytokines in a homogenous test format with femtomolar detection sensitivities in 1-?l samples, and we exemplify its utility in situations when only minute sample amounts are available.

Gullberg, Mats; Gustafsdottir, Sigrun M.; Schallmeiner, Edith; Jarvius, Jonas; Bjarnegard, Mattias; Betsholtz, Christer; Landegren, Ulf; Fredriksson, Simon

2004-01-01

253

The effect of tibiofemoral loading on proximal tibiofibular joint motion*  

PubMed Central

The human proximal tibiofibular joint (PTFJ) and its relationship to overall knee joint mechanics have been largely unexplored. This study describes force/displacement data from experiments done on four human cadaveric knee specimens and general conclusions obtained with the help of a statistical modeling technique. Specimens were rigidly affixed at the tibia to a force plate and the femur was attached to a custom made device allowing for manual load application. Motion of the fibular head was tracked relative to the tibial plateau by means of reflective markers and a high speed digital camera synchronized with the force plate data stream. Each specimen was subjected to a range of loading conditions and a quadratic regression model was created and then used to predict the specimen's response to standardized loading conditions and compare these across specimens. Statistical analysis was performed with a three-factor analysis of variance with repeated measures. Proximal tibiofibular joint motion was largest in the anterior-posterior direction with translations of 1–3 mm observed during a range of physiological loading conditions. The applied internal-external rotation moment had a significant effect on proximal tibiofibular joint translation (P < 0.05). Effects of varus-valgus loading and flexion angle were seen in some specimens. This study demonstrates that substantial proximal tibiofibular joint motion can occur in physiologic loading states. Preservation of proximal tibiofibular joint function, and anatomical variations which affect this function, may need to be considered when designing surgical procedures for the knee joint.

Scott, Jacob; Lee, Ho; Barsoum, Wael; van den Bogert, Antonie J

2007-01-01

254

Developmental Changes in Proximal Tubule Tight Junction Proteins  

PubMed Central

We demonstrated previously that neonatal proximal tubules have a lower passive paracellular permeability to chloride ions and higher resistance than that of adult proximal tubules. In addition, administration of thyroid hormone to neonates, before the normal maturational increase in serum thyroid hormone levels, prematurely accelerates the developmental increase in chloride permeability to adult levels. To test the hypothesis that there is a maturational change in tight junction proteins and that thyroid hormone mediates these changes, we examined the two known tight junction proteins present in proximal tubules, occludin and claudin 2. Using immunoblot and immunohistochemistry, we demonstrated that claudin 2 has a 4-fold greater abundance in neonatal proximal tubules than in adult tubules. Occludin, however, has a 4-fold greater expression in adult tubules than in neonatal tubules. Administration of thyroid hormone to neonates did not affect claudin 2 expression, occludin expression, or the transepithelial resistance in rat proximal tubule cells in vitro. In conclusion, there are postnatal maturational changes in tight junction proteins. The factors that cause these maturational changes are unknown but unlikely to be due solely to the maturational increase in thyroid hormone.

HADDAD, MAHA; LIN, FANGMING; DWARAKANATH, VANGIPURAM; CORDES, KIMBERLY; BAUM, MICHEL

2014-01-01

255

Roles of Renal Proximal Tubule Transport in Acid/Base Balance and Blood Pressure Regulation  

PubMed Central

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.

Nakamura, Motonobu; Shirai, Ayumi; Yamazaki, Osamu; Suzuki, Masashi; Horita, Shoko; Yamada, Hideomi

2014-01-01

256

Role of renal proximal tubule transport in thiazolidinedione-induced volume expansion  

PubMed Central

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.

Seki, George; Endo, Yoko; Suzuki, Masashi; Yamada, Hideomi; Horita, Shoko; Fujita, Toshiro

2012-01-01

257

Role of intracellular calcium in renal proximal tubule cell volume regulation.  

PubMed

Osmoregulatory Ca2+ signaling in hypotonic solutions was studied with videometric techniques in 158 proximal renal tubules isolated from the teleost Carassius auratus. Absence of extracellular Ca2+, hypoxia (23 mmHg), or NaCN (3 mM) did not alter regulatory volume decreases (RVD). Nevertheless, decrements of intracellular Ca2+ via the A23187 ionophore or after intracellular Ca2+ chelation with indo-1/AM (5 microM) inhibited RVD. In tubules depleted of Ca2+, RVD could only be fully elicited when intracellular Ca2+ pulses were given within 1 min after hypotonic stimulation. While inhibition of Ca2+ release from the endoplasmic reticulum (ER) with 8-(diethylamino)octyl 3,4,5-trimethoxybenzoate hydrochloride (TMB-8, 50 microM) blunted RVD, some of its effects could be reversed with the anion carrier tributyltin (1 microM). Dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP, 0.5 and 1.0 mM) and forskolin (0.25 mM) also impeded RVD; however, their effects could be partially reversed with the K+ ionophore gramicidin (0.5 microM). In conclusion, in Carassius auratus proximal renal tubule cells, RVD is activated by an intracellular Ca2+ signal that likely emanates from the ER and not from the extracellular media or the mitochondrial Ca2+ pool. Ca2+ activation of a cAMP-modulated osmoregulatory K+ channel appears to play an important role. PMID:1332517

Terreros, D A; Kanli, H

1992-11-01

258

Common relationships among proximate composition components in fishes  

USGS Publications Warehouse

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.

2008-01-01

259

Volar plate arthroplasty for closed proximal interphalangeal joint injuries.  

PubMed

The anatomy and histology of the volar plate at the proximal interphalangeal joint and the mechanism of fracture/subluxation of the base of the middle phalanx in closed proximal interphalangeal joint injuries is reviewed. Our current technique of repair for these injuries and its evolution from Eaton's original procedure is described. The results of 71 cases of volar plate arthroplasty performed over a five-year period for fracture/subluxations of the proximal interphalangeal joints are presented with follow-up ranging from six months to four years. 62 (87%) patients achieved a stable pain-free joint with a range of motion from 5 degrees to 95 degrees within two months. Complications were uncommon and correctable with an overall eventual patient satisfaction rate of 94%. PMID:1402271

Durham-Smith, G; McCarten, G M

1992-08-01

260

A Flexible Proximity Sensor Fully Fabricated by Inkjet Printing  

PubMed Central

A flexible proximity sensor fully fabricated by inkjet printing is proposed in this paper. The flexible proximity sensor is composed of a ZnO layer sandwiched in between a flexible aluminum sheet and a web-shaped top electrode layer. The flexible aluminum sheet serves as the bottom electrode. The material of the top electrode layer is nano silver. Both the ZnO and top electrode layers are deposited by inkjet printing. The fully inkjet printing process possesses the advantages of direct patterning and low-cost. It does not require photolithography and etching processes since the pattern is directly printed on the flexible aluminum sheet. The prototype demonstrates that the presented flexible sensor is sensitive to the human body. It may be applied to proximity sensing or thermal eradiation sensing.

Wang, Chin-Tsan; Huang, Kuo-Yi; Lin, David T. W.; Liao, Wei-Chia; Lin, Hua-Wei; Hu, Yuh-Chung

2010-01-01

261

VCSEL-based microsensors for photonic proximity fuzing of munitions  

NASA Astrophysics Data System (ADS)

This paper describes technologies developed at Sandia National Laboratories to support a joint DoD/DoE initiative to create a compact, robust, and affordable photonic proximity sensor for munitions fuzing. The proximity fuze employs high-power vertical-cavity surface-emitting laser (VCSEL) arrays, resonant-cavity photodetectors (RCPDs), and refractive micro-optics that are integrated within a microsensor whose volume is approximately 0.01 cm3. Successful development and integration of these custom photonic components should enable a g-hard photonic proximity fuze that replaces costly assemblies of discrete lasers, photodetectors, and bulk optics. Additional applications of this technology include void sensing, ladar and short-range 3-D imaging.

Keeler, G. A.; Mar, A.; Geib, K. M.; Hsu, A. Y.; Serkland, D. K.; Peake, G. M.

2008-08-01

262

Proximal femoral reconstruction with a constrained acetabulum in oncologic patients.  

PubMed

Metallic endoprostheses are used for oncological reconstruction around the proximal femur and hip joint. Common modes of failure with hemiarthroplasty or standard hip arthroplasty after proximal femoral replacement include dislocation, late hip pain, and infection. The authors reviewed hospital records to identify patients undergoing constrained tripolar hip arthroplasty for oncological reasons between 2002 and 2012. Inclusion criterion was at least 12-cm proximal femoral resection, including patients with total femur reconstruction. A total of 33 patients were reviewed. Information regarding demographics, length of follow-up, treatment characteristics, and patient outcomes was extracted. Average follow-up for all patients was 912.33 days (30.4 months). Average follow-up was 1396.1 days for living patients and 428.6 days for deceased patients. Average estimated blood loss was 462.12 cc: an average of 1080 cc for patients undergoing total femoral resection and replacement and 315.8 cc for patients undergoing proximal femoral resection and replacement. Average operative time was 137.7 minutes: an average of 205 minutes for patients undergoing total femoral resection and replacement and 119.1 minutes for patients undergoing proximal femoral resection and replacement. Average Musculoskeletal Tumor Society score was 21.7. There were no dislocations in the cohort. A constrained tripolar device can be safely used for oncological proximal femoral reconstructions while minimizing the risk of dislocation. Positioning of the acetabular implant in neutral anatomic version in conjunction with a neutral-placed femoral component provides the greatest range of motion, reduction of liner impingement, and improved hip stability. PMID:24679207

Jawad, Muhammad Umar; Brien, Earl W

2014-02-01

263

[Determination of proximal chemical composition of squid (dosidicus gigas) and development of gel products].  

PubMed

The good nutritional properties of meat from big squid (Dosidicus gigas) living on the Chilean coast, was determined through its proximal composition 70 cal/100 g fresh meat; 82.23 +/- 0.98% moisture; 15.32 +/- 0.93% protein; 1.31 +/- 0.12% ashes; 0.87 +/- 0.18% fat and 0.27% NNE (non-nitrogen extract). The big squid meat was used to develop a gel product which contained NaCl and TPP. It was necessary to use additives for gel preparation, such as carragenin or alginate or egg albumin, due to the lack of gelation properties of squid meat. Formulations containing egg albumin showed the highest gel force measured by penetration as compared to those that contained carragenin or alginate. PMID:10488395

Abugoch, L; Guarda, A; Pérez, L M; Paredes, M P

1999-06-01

264

Gastric emptying following vagotomy and antrectomy and proximal gastric vagotomy.  

PubMed Central

Gastric emptying of solid meals labelled with 129Cs was studied in patients for up to one year after vagotomy and antrectomy or after proximal gastric vagotomy. Significant delay was found one month after vagotomy and antrectomy but this had returned to normal by six months. No delay was found after proximal gastric vagotomy. The effect of posture on gastric emptying was also studied in the same subjects. No significant differences were found between gastric emptying in the supine or sitting positions after solid meals.

Kalbasi, H; Hudson, F R; Herring, A; Moss, S; Glass, H I; Spencer, J

1975-01-01

265

Multifocal motor neuropathy presenting as chronic progressive proximal leg weakness.  

PubMed

We report on a 47-year-old man with a 12-year history of progressive and ultimately severe proximal weakness of his right lower limb. Motor conduction block at the unaffected tibial nerve and positive IgM antibodies against GM1 gangliosides lead us to suggest a diagnosis of oligosymptomatic multifocal motor neuropathy. He rapidly responded to intravenous immunoglobulins, with complete remission lasting 4 weeks, and had a repeated treatment response to intravenous immunoglobulins during subsequent exacerbations. The proximal involvement may represent another unusual clinical manifestation of multifocal motor neuropathy. PMID:15145341

Mäurer, Mathias; Stoll, Guido; Toyka, Klaus V

2004-06-01

266

Inverse Proximity Effect in Superconductor-ferromagnet Bilayer Structures  

SciTech Connect

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 (F) induces a finite magnetization in the superconducting (S) 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.[1].

Xia, Jing

2010-04-05

267

Phenytoin induced vitamin d deficiency presenting as proximal muscle weakness  

Microsoft Academic Search

A 6-year-old girl presented with proximal muscle weakness of lower limbs. She was receiving phenytoin for epilepsy for 2 years.\\u000a Serum phenytoin level was within therapeutic range. Serum 25(OH) vitamin D was low (5ng\\/mL) and serum parathyroid hormone\\u000a level was high. After administration of oral vitamin D, muscle weakness improved and vitamin D level increased to 39.11ng\\/mL.\\u000a Proximal muscle weakness

M. M. A. Faridi; Anju Aggarwal

2010-01-01

268

Inverse proximity effect in a strongly correlated electron system.  

PubMed

An anomalous superconducting proximity effect between a strongly correlated electron system and a normal metal is demonstrated. The model system is a 2D ultrathin superconducting quench-condensed Pb film. Such a highly disordered film has a reduced transition temperature (T(c) = 1.7 K) due to the strong e(-)-e(-) interaction. Instead of weakening the superconductivity, an overlayer of Ag on Pb induces an increase of both the T(c) and the gap. The restoration of the electron screening brought about by the quasiparticles from the normal metal can explain this striking inverse proximity effect. PMID:12005705

Bourgeois, Olivier; Frydman, Aviad; Dynes, R C

2002-05-01

269

Stercoral perforation of the colon proximal to an end colostomy.  

PubMed Central

Stercoral perforation of the colon is rare, and has not previously been reported as a postoperative complication, proximal to an end colostomy. Two such cases are reported; in addition in one the stercoral perforation was recurrent, emphasizing the multifocal nature of the disease. Both cases demonstrate the failure of standard techniques to deal with scybala in the loaded proximal colon. It is, therefore, suggested that intra-operative orthograde colonic lavage is indicated to protect a terminal colostomy from the risk of stercoral perforation in such cases.

Serpell, J. W.; Sen, M.; Giddins, G.; Nicholls, R. J.; Bradfield, W. J.

1991-01-01

270

Ectrodactyly and proximal/intermediate interstitial deletion 7q  

SciTech Connect

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

1995-03-13

271

Investigation of proximity effects in electron microscopy and lithography  

NASA Astrophysics Data System (ADS)

A fundamental challenge in lithographic and microscopic techniques employing focused electron beams are so-called proximity effects due to unintended electron emission and scattering in the sample. Herein, we apply a method that allows for visualizing electron induced surface modifications on a SiN substrate covered with a thin native oxide layer by means of iron deposits. Conventional wisdom holds that by using thin membranes proximity effects can be effectively reduced. We demonstrate that, contrary to the expectation, these can be indeed larger on a 200 nm SiN-membrane than on the respective bulk substrate due to charging effects.

Walz, M.-M.; Vollnhals, F.; Rietzler, F.; Schirmer, M.; Steinrück, H.-P.; Marbach, H.

2012-01-01

272

Proximal myopathy as an unusual presenting feature of celiac disease.  

PubMed

A 37-year-old woman presented with back pain, diffuse musculoskeletal pain, and muscle weakness without marked gastrointestinal symptoms. She complained of difficulty in walking and bilateral hip pain for the preceding year. Clinical examination revealed proximal muscle weakness especially in the lower extremities and a waddling gait pattern. Laboratory parameters and radiographic findings revealed the diagnosis of osteomalacia. The etiology of osteomalacia was investigated and a diagnosis of celiac disease was established. As osteomalacia symptoms may be the only presenting feature of celiac disease, it should be considered in the differential diagnosis of patients presenting with proximal muscle weakness and diffuse musculoskeletal pain. PMID:15349797

Kozanoglu, Erkan; Basaran, Sibel; Goncu, M Kamil

2005-02-01

273

Elemental microanalysis of organelles in proximal tubules. II. Effects of oxygen deprivation.  

PubMed

This communication describes the effects of anoxia on rabbit proximal renal tubule element (ion) content by using high-resolution electron probe x-ray microanalytical imaging to obtain quantitative elemental data from subcellular compartments not previously resolvable with low-resolution imaging. These organelles and regions include the heterochromatin and euchromatin of the nucleus and the microvilli of the apical brush border, in addition to mitochondria, lysosomes, and cytoplasm. Anoxia of 40-min duration caused the expected decrease in K and increase in Na and Cl concentrations in the tubules with the cytoplasmic K:Na ratio declining to 0.13:1. These changes were accompanied by decreases in ATP and total K contents, and an increase in lactate dehydrogenase release. Swelling occurred in some cells as evidenced by ultrastructural changes. No alterations were evident after oxygen deprivation in Ca content of cytoplasm (control, 6.7 +/- 0.6 versus anoxia, 7.6 +/- 0.7 nmol/mg dry wt) or mitochondria (control, 4.0 +/- 0.4 versus anoxia, 4.9 +/- 0.6 nmol/mg dry wt) or in S content of recognizable lysosomes (control, 314 +/- 11 versus anoxia, 325 +/- 12 nmol/mg dry wt). Brush border (microvillus) Ca content was higher than cytoplasmic Ca content during normoxia (10.7 +/- 0.9 nmol/mg dry wt) and increased further during anoxia (17.0 +/- 1.0 nmol of Ca/mg dry wt). The finding of higher Ca content within the brush border region during normoxia is unexpected and novel, because such results suggest that Ca homeostasis in the apical elaboration of the proximal cell may be different from that in the cytoplasm. The results also raise the possibility that an increase in Ca content in the brush border membrane region may be involved in the pathogenesis of renal cell injury. PMID:1912394

Spencer, A J; LeFurgey, A; Ingram, P; Mandel, L J

1991-06-01

274

Proximity effect in normal metal high-Tc superconductor contacts  

NASA Astrophysics Data System (ADS)

We study the proximity effect in good contacts between normal metals and high-Tc (dx^2-y^2-wave) superconductors. We present theoretical results for the spatially dependent order parameter and local density of states, including effects of impurity scattering in the two sides, s-wave pairing interaction in the normal metal side (attractive or repulsive) and subdominant s-wave paring in the superconductor side. For the [100] orientation, a real combination d+s of the order parameters is always found. The spectral signatures of the proximity effect in the normal metal include a suppression of the low-energy density of states and a finite-energy peak structure. These features are mainly due to the impurity self-energies, which dominate over the effects of induced pair potentials. For the [110] orientation, for moderate transparencies, induction of a d+is order parameter on the superconductor side leads to a proximity induced is-order parameter also in the normal metal. The spectral signatures of this type of proximity effect are potentially useful for probing time-reversal symmetry breaking at a [110] interface.

Lofwander, Tomas

2005-03-01

275

Proximity effect in normal metal-high- Tc superconductor contacts  

NASA Astrophysics Data System (ADS)

We study the proximity effect in good contacts between normal metals and high- Tc ( dx2-y2- -wave) superconductors. We present theoretical results for the spatially dependent order parameter and local density of states, including effects of impurity scattering in the two sides, s -wave pairing interaction in the normal metal side (attractive or repulsive) and subdominant s -wave paring in the superconductor side. For the [100] orientation, a real combination d+s of the order parameters is always found. The spectral signatures of the proximity effect in the normal metal include a suppression of the low-energy density of states and a finite-energy peak structure. These features are mainly due to the impurity self-energies, which dominate over the effects of induced pair potentials. For the [110] orientation, for moderate transparencies, induction of a d+is order parameter on the superconductor side leads to a proximity induced is order parameter also in the normal metal. The spectral signatures of this type of proximity effect are potentially useful for probing time-reversal symmetry breaking at a [110] interface.

Löfwander, Tomas

2004-09-01

276

Proximity Drawings: Three Dimensions Are Better than Two? (Extended Abstract)  

Microsoft Academic Search

We consider weak Gabriel drawings of unbounded degree trees in the three-dimensional space. We assume a minimum distance between any two vertices. Under the same assumption, there exists an exponential area lower bound for general graphs. Moreover, all previously known algorithms to construct (weak) proximity drawings of trees, gener- ally produce exponential area layouts, even when we restrict ourselves to

Paolo Penn; Paola Vocca

1998-01-01

277

Stress fracture of the proximal femur after screw removal  

Microsoft Academic Search

We describe a case of stress fracture of the proximal femur occurring in a patient after removal of an internal fixation device for a comminuted subtrochanteric fracture. The presenting clinical picture resembled a late postoperative infection with a positive technetium and gallium bone scan and normal radiological findings. The stress fracture occurred after removal of the fixation device when the

S. Velkes; J. Nerubay; F. Lokiec

1996-01-01

278

Cancellous Bone Strength at the Proximal Human Tibia  

Microsoft Academic Search

Machined specimens from ten cadaver proximal tibiae were tested in compression to study the variation of mechanical strength with the distance from the joint surface. There was a statistically significant reduction of stiffness and strength with increasing distance from the joint beneath the lateral condyle and the intercondylar area; at the medial condyle no such reduction could be demonstrated. Linear

Ivan Hvid; Jørn Jensen

1984-01-01

279

Open-wedge osteotomy of the proximal tibia with hemicallotasis  

Microsoft Academic Search

onventional high tibial osteotomy for osteoarthritis of the medial compartment of the knee with closed-wedge or dome osteotomy (DMO) may produce shortening of the patellar tendon and loss of inclination of the proximal tibial plateau or of the offset of the tibial condyle relative to its bony axis. This can make subsequent total knee arthroplasty technically demanding. We undertook a

E. Nakamura; H. Mizuta; S. Kudo; K. Takagi; K. Sakamoto

2001-01-01

280

Broadband circularly polarized proximity coupled microstrip antenna for HIPERLAN\\/2  

Microsoft Academic Search

The characteristics of a proximity coupled microstrip antenna, for the application in high performance local area network type 2 (HIPERLAN\\/2) are reported here. This miniaturized circularly polarized microstrip antenna has wide bandwidth. The simulated results using IE3D software are verified by measurement.

J. S. Roy; M. Thomas; Jayanta Ghosh

2007-01-01

281

Scaffolding critical thinking in the zone of proximal development  

Microsoft Academic Search

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. There was very little evidence of critical thinking

Rob Wass; Tony Harland; Alison Mercer

2011-01-01

282

Synchronization of coupled harmonic oscillators in a dynamic proximity network  

Microsoft Academic Search

In this paper, we revisit the synchronization problems for coupled harmonic oscillators in a dynamic proximity network. Unlike many existing algorithms for distributed control of complex dynamical networks that require explicit assumptions on the network connectivity, we show that the coupled harmonic oscillators can always be synchronized, without imposing any network connectivity assumption. Moreover, we also investigate the synchronization with

Housheng Su; Xiaofan Wang; Zongli Lin

2009-01-01

283

West and south elevations, view to northeast. Proximity of house ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

West and south elevations, view to northeast. Proximity of house and trees precluded photography of north and east elevations, but building is symmetrical. Entry is in east elevation; windmill was mounted at third story level on north elevation. - Drew-Sherwood Farm, Tank House, 7927 Elk Grove Boulevard, Elk Grove, Sacramento County, CA

284

Custom mega-prosthetic replacement for proximal humeral tumours  

Microsoft Academic Search

We used custom mega-prostheses in 57 patients with aggressive benign and malignant tumours of the proximal humerus. The most common tumour was osteosarcoma, followed by giant cell tumour and chondrosarcoma. We achieved extra-articular and wide resection margins in all primary malignant tumours and narrow margins in benign and metastatic tumours. Six patients died of disease, 4 patients developed local recurrences

N. Mayilvahanan; M. Paraskumar; A. Sivaseelam; S. Natarajan

2006-01-01

285

Proximity soundings of thundersnow in the central United States  

Microsoft Academic Search

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

Angela M. Oravetz; David Gaede; Evan Bookbinder; Anthony R. Lupo; Christopher J. Melick; Larry L. Smith; Rashida Thomas; Rachel Redburn; Brian P. Pettegrew; Amy E. Becker

2006-01-01

286

Fixation of proximal humeral fractures with the Polarus nail  

Microsoft Academic Search

Thirty patients with fractures of the proximal humerus were treated by internal fixation with an intramedullary locked nail. Fourteen of these patients were more than 60 years of age; 23 patients had 2-part fractures (surgical neck fractures) and were operated on within an average of 3 days after injury. At follow-up, 20 (80%) of 25 patients showed satisfactory to excellent

C. Rajasekhar; P. S. Ray; M. S. Bhamra

2001-01-01

287

Rendezvous and Proximity Operations of the Space Shuttle  

NASA Technical Reports Server (NTRS)

Space Shuttle rendezvous missions present unique challenges that were not fully recognized when the Shuttle was designed. Rendezvous targets could be passive (i.e., no lights or transponders), and not designed to facilitate Shuttle rendezvous, proximity operations, and retrieval. Shuttle reaction control system jet plume impingement on target spacecraft presented induced dynamics, structural loading, and contamination concerns. These issues, along with limited reaction control system propellant in the Shuttle nose, drove a change from the legacy Gemini/Apollo coelliptic profile to a stable orbit profile, and the development of new proximity operations techniques. Multiple scientific and on-orbit servicing missions, and crew exchange, assembly and replenishment flights to Mir and to the International Space Station drove further profile and piloting technique changes. These changes included new proximity operations, relative navigation sensors, and new computer generated piloting cues. However, the Shuttle's baseline rendezvous navigation system has not required modification to place the Shuttle at the proximity operations initiation point for all rendezvous missions flown.

Goodman, John L.

2005-01-01

288

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

2005-01-01

289

Surgical treatment of fibrous dysplasia in the proximal femur  

PubMed Central

The aim of this study was to summarize oncological and functional results and to investigate surgical treatment methods and efficacies by conducting a retrospective study of patients with fibrous dysplasia (FD) in the proximal femur. A total of 15 patients with FD in the proximal femur were selected. Among them, 12 cases were monostotic and 3 cases were polyostotic. In addition, 2 cases were accompanied by shepherd’s crook deformity. All cases received internal fixation following focus curettage and impaction grafting. Among them, valgus osteotomy was conducted for 2 cases of shepherd’s crook deformity. All patients were followed up for 12–32 months. For 2 patients with shepherd’s crook deformity in the proximal femur, the collodiaphysial angle was recovered after an orthopedic procedure following osteotomy. In addition, no patient presented with postoperative recurrent lesions. At 3 months following surgery, local bone resorption was visible in the bone grafting area. Between 8 and 12 months after surgery, the bones in the bone grafting area had healed, pain had disappeared and gaits were nearly normal. An effective internal fixation following thorough focus curettage and allograft bone transplantation is an effective method of treating FD in the proximal femur. For patients with shepherd’s crook deformity, it is also necessary to perform valgus osteotomy to recover hip joint function.

TONG, ZHICHAO; ZHANG, WENTAO; JIAO, NING; WANG, KUNZHENG; CHEN, BO; YANG, TUANMIN

2013-01-01

290

Residential proximity to gasoline service stations and preterm birth.  

PubMed

Preterm birth (PTB) is a growing public health problem potentially associated with ambient air pollution. Gasoline service stations can emit atmospheric pollutants, including volatile organic compounds potentially implicated in PTB. The objective of this study was to evaluate the relationship between residential proximity to gasoline service stations and PTB. Singleton live births on the Island of Montreal from 1994 to 2006 were obtained (n=267,478). Gasoline service station locations, presence of heavy-traffic roads, and neighborhood socioeconomic status (SES) were determined using a geographic information system. Multivariable logistic regression was used to analyze the association between PTB and residential proximity to gasoline service stations (50, 100, 150, 200, 250, and 500 m), accounting for maternal covariates, neighborhood SES, and heavy-traffic roads. For all distance categories beyond 50 m, presence of service stations was associated with a greater odds of PTB. Associations were robust to adjustment for maternal covariates for distance categories of 150 and 200 m but were nullified when adjusting for neighborhood SES. In analyses accounting for the number of service stations, the likelihood of PTB within 250 m was statistically significant in unadjusted models. Associations were, however, nullified in models accounting for maternal covariates or neighborhood SES. Our results suggest that there is no clear association between residential proximity to gasoline service stations in Montreal and PTB. Given the correlation between proximity of gasoline service stations and SES, it is difficult to delineate the role of these factors in PTB. PMID:23625119

Huppé, Vicky; Kestens, Yan; Auger, Nathalie; Daniel, Mark; Smargiassi, Audrey

2013-10-01

291

Operative versus nonoperative treatment in complex proximal humeral fractures.  

PubMed

This updated meta-analysis investigated whether operative treatment is superior to nonoperative treatment in complex proximal humeral fractures. The authors searched the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE. Randomized controlled trials that evaluated operative vs nonoperative treatment for exclusively 3- or 4-part proximal humeral fractures were considered. Six studies with a total of 287 patients who had proximal humeral fractures were included. According to the meta-analysis, no statistically significant differences were found between operative and nonoperative treatment in Constant-Murley shoulder scores (Constant scores); Disabilities of the Arm, Shoulder, and Hand scores; total complication events; mortality; infection; nonunion; avascular necrosis; osteoarthritis; redisplacement of fractures; or dislocation or resorption of tuberosity. For health-related quality of life, EuroQol-5D (EQ-5D) favored operative treatment, but 15D scores showed no significant difference. Compared with nonoperative treatment, open reduction and internal fixation required significantly more additional surgeries (risk ratio, 6.50; 95% confidence interval, 1.54-27.50; P=.01), and more penetrations into joint space occurred (risk ratio, 9.56; 95% confidence interval, 2.27-40.13; P=.002). The limited evidence suggests that no convincing findings support the use of either open reduction and internal fixation or hemiarthroplasty for the treatment of complex proximal humeral fractures. The findings of the current study should be interpreted cautiously because of the modest sample size and the short follow-up period. PMID:24810816

Mao, Zhi; Zhang, Lihai; Zhang, Licheng; Zeng, Xiantao; Chen, Shuo; Liu, Daohong; Zhou, Zhirui; Tang, Peifu

2014-05-01

292

Multiple-Target Tracking With Binary Proximity Sensors  

Microsoft Academic Search

Recent work has shown that, despite the minimal information provided by a binary proximity sensor, a network of these sensors can provide remarkably good target tracking performance. In this article, we examine the performance of such a sensor network for tracking multiple targets. We begin with geometric arguments that address the problem of counting the number of distinct targets, given

Jaspreet Singh; Rajesh Kumar; Upamanyu Madhow; Subhash Suri; Richard Cagley

2011-01-01

293

PROXIMITY OF LOUISIANA SANITARY LANDFILLS TO WETLANDS AND DEEPWATER HABITATS  

EPA Science Inventory

Sanitary landfills can cause considerable harm to sensitive ecosystems if they are not properly located, designed, and managed. The proximity of Louisiana sanitary landfills to wetlands and deepwater habitats was determined by drawing three concentric 1/4 mile, 1/2 mile, and 1 mi...

294

Arterial blood supply of the proximal humeral epiphysis  

Microsoft Academic Search

The arterial blood supply of the proximal humeral epiphysis is known to derive mainly from the anterior humeral circumflex a. (ACA), but this description may minimize the role of the posterior circumflex humeral a. (PCA). The studies of Laing [9] and Gerber [3] emphasized the role of the ACA and of its branches, the ascending anterolateral artery and arcuate artery

F. Duparc; J.-M. Muller; P. Frçger

2001-01-01

295

Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.  

PubMed

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

2012-06-01

296

A Combined Method to Compute the Proximities of Asteroids  

Microsoft Academic Search

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 Simovljevic's (1974) graphical method and on the transcendent equations developed by Lazovic (1993). The method is tested on 2 997

S. Segan; S. Milisavljevic; D. Marceta

2011-01-01

297

Proximity to Coast Is Linked to Climate Change Belief  

PubMed Central

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.

Milfont, Taciano L.; Evans, Laurel; Sibley, Chris G.; Ries, Jan; Cunningham, Andrew

2014-01-01

298

Interactive displays for trajectory planning and proximity operations  

Microsoft Academic Search

Rendezvous, docking, and other Space Station proximity operations (PROX OPS) will be conducted routinely in space. Real-time interactive visual aids and planning tools will be helpful, if not necessary, for future missions both in preflight training and on orbit. Two such displays, eivaN and Navie, are currently available for examination and human factors testing. A study was conducted in which

Adam R. Brody; Stephen R. Ellis; Arthur Grunwald; Richard F. Haines

1993-01-01

299

Proximal dup(10q): Case report and literature review  

SciTech Connect

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

1994-09-01

300

Proximal Femoral Reconstructions with Bone Impaction Grafting and Metal Mesh  

PubMed Central

Extensive circumferential proximal cortical bone loss is considered by some a contraindication for impaction bone grafting in the femur. We asked whether reconstruction with a circumferential metal mesh, impacted bone allografts, and a cemented stem would lead to acceptable survival in these patients. We retrospectively reviewed 14 patients (15 hips) with severe proximal femoral bone defects (average, 12 cm long; 14 type IV and one type IIIB using the classification of Della Valle and Paprosky) reconstructed with this method. The minimum followup was 20 months (average, 43.2 months; range, 20–72 months). Preoperative Merle D’Aubigné and Postel score averaged 4.8 points. With revision of the stem as the end point, the survivorship of the implant was 100% at one year and 86.6% at 72 months. The mean functional score at last followup was 14.4 points. We observed two fractures of the metal mesh at 31 and 48 months in cases reconstructed with a stem that did not bypass the mesh. Dislocation (3 cases) and acute deep infection (3 cases) were the most frequent complications. Patients with complete absence of the proximal femur may be candidates for biological proximal femoral reconstructions using this salvage procedure. Bone impaction grafting must be a routine technique if this method is selected. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Comba, Fernando; Piccaluga, Francisco

2009-01-01

301

Delinquency and class: A test of the proximity principle  

Microsoft Academic Search

Criminologists have not found consistent evidence that class is related to crime. This study attempts to clarify the class-crime relationship by using a framework drawn from the social psychology literature. We test the proximity principle, which proposes that measures of social class which shape youths' everyday experiences will be the aspects of social class which influence their personality and behavior.

G. Roger Jarjoura; Ruth A. Triplett

1997-01-01

302

Multipoint Tabu Search based on Proximate Optimality Principle  

Microsoft Academic Search

This paper proposes an algorithm - multi-point tabu search based on proximate optimality principle (POP) - which has several advantages for solving combinatorial optimization problems. The proposed algorithm is applied to several typical combinatorial optimization problems in order to verify the performance of the proposed algorithm. The simulation results indicate that the proposed method has higher optimality than the conventional

Daichi Niizuma; Keiichiro Yasuda; A. Ishigame

2006-01-01

303

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.

1989-01-01

304

Electronic Design of a Slant-Range Optical Proximity Sensor.  

National Technical Information Service (NTIS)

This paper describes the electronic design of a slant-range optical proximity sensor using a pulse-modulated injection laser for the transmitter and a direct-detection receiver for the collection of target returns, much after the manner of a conventional ...

J. Vanderwall

1976-01-01

305

Active ion transport in the renal proximal tubule. I. Transport and metabolic studies  

PubMed Central

Various aspects of the interrelationship between ion transport and cellular metabolism were investigated using a suspension of rabbit cortical tubules that were mainly proximal in nature. Using the intact tubules, the compartmentation of K within the renal cell was studied by performing 42K uptake studies. The oxygen consumption (QO2) of the tubules was measured under similar conditions, as well as when the Na pump was stimulated by increasing Na+ entry with nystatin. In addition, the state 3 rate of respiration was measured when the mitochondria of digitonin-permeabilized tubules were stimulated by ADP. At 37 and 25 degrees C, a single-compartmental uptake of 42K was observed, which suggests that extracellular K+ communicates with a single compartment within the renal cell. Between 37 and 15 degrees C, the ouabain- sensitive QO2 and the initial 42K uptake rate were parallel in an Arrhenius-type plot, which indicated that active ion transport and oxidative phosphorylation remain tightly coupled within this temperature range. At all temperatures between 37 and 15 degrees C, nystatin stimulated the QO2, which demonstrates that the entry of Na+ into the renal cells was rate limiting for active Na+ transport throughout this temperature range. Between 37 and 20 degrees C, the nystatin-stimulated QO2 was nearly equal to the state 3 rate of respiration, which suggests that active ion transport may be limited by ATP availability under these conditions. At 15 degrees C, nystatin addition stimulated the QO2 well below the state 3 respiratory rate.

1984-01-01

306

Proximal Tibia Osteoarticular Allografts in Tumor Limb Salvage Surgery  

PubMed Central

Background Resection of large tumors of the proximal tibia may be reconstructed with endoprostheses or allografts with fixation. Endoprosthetic replacement is associated with high failure rates and complications. Proximal tibia osteoarticular allografts after tumor resection allows restoration of bone stock and reconstruction of the extensor mechanism, but the long-term failure rates and complications are not known. Questions/purposes We therefore determined (1) the middle- and long-term survival of proximal tibia osteoarticular allografts, (2) their complications, and (3) functional (Musculoskeletal Tumor Society score) and radiographic (International Society of Limb Salvage) outcomes in patients treated with this reconstruction. Patients and Methods We retrospectively reviewed 52 patients (58 reconstructions including six repeat reconstructions) who underwent osteoarticular proximal tibia allograft reconstructions after resection of a bone tumor. The minimum followup of the 46 surviving patients was 72 months (mean, 123 months; range, 10–250 months). Survival of the allograft was estimated using the Kaplan-Meier method. We documented outcomes using the Musculoskeletal Tumor Society functional scoring system and the International Society of Limb Salvage radiographic scoring system. Results Six patients died from tumor-related causes without allograft failure before the 5-year radiographic followup. At last followup, 32 of the 52 remaining allografts were still in place; 20 failed owing to infections, local recurrences, or fractures. Overall allograft survival was 65% at 5 and 10 years, with an average Musculoskeletal Tumor Society functional score of 26 points and an average radiographic result of 87%. Conclusions Based on these data we believe proximal tibia osteoarticular allograft is a valuable reconstructive procedure for large defects after resection of bone tumors. Level of Evidence Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Ayerza, Miguel A.; Farfalli, German; Aponte-Tinao, Luis A.

2009-01-01

307

Proximal scaphoid arthroplasty using the medial femoral trochlea flap.  

PubMed

Background The medial trochlea of the femur (medial femoral trochlea, MFT) provides a source of convex osteocartilaginous vascularized bone that has been demonstrated to have a similar contour to the proximal scaphoid. This provides a potential solution for difficult recalcitrant proximal pole scaphoid nonunions. Materials and Methods Sixteen consecutive patients who underwent MFT proximal scaphoid arthroplasty were reviewed. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months. The results of this cohort were previously reported in detail but are summarized herein. Description of Technique The ability to reconstruct both bone and cartilage of the nonunion enables the surgeon to resect the nonunited proximal pole to prepare for scaphoid reconstruction. A segment of osteocartilaginous MFT is harvested in dimensions required by the scaphoid defect. The MFT segment is harvested on the transverse branch of the descending geniculate vessels. Fixation may be achieved with ease due to the size of the reconstructed segment. Results Computed tomography imaging demonstrated 15 of 16 reconstructed scaphoids achieving osseous union. Follow-up range of motion (ROM) of the wrist averaged 46.0° extension (range 28-80°) and 43.8° flexion (range 10-80°), which was similar to preoperative (average 45.7° extension and 43.0° flexion). Scapholunate angles remained unaffected (51.6° preoperatively and 48.6° postoperatively), indicating preservation of carpal relationships. Conclusions Vascularized MFT flaps provide a useful tool in the treatment of difficult proximal pole scaphoid nonunions. Early follow-up demonstrates high rate of achieving union with acceptable ROM and good pain relief. PMID:24436821

Higgins, James P; Burger, Heinze K

2013-08-01

308

The AO\\/ASIF-proximal femoral nail (PFN): a new device for the treatment of unstable proximal femoral fractures  

Microsoft Academic Search

Currently available intramedullary devices for the treatment of unstable pertrochanteric femoral fractures are technically demanding and show a considerable failure rate due to their massiveness and the persistent rotational instability of the head–neck fragment. The Arbeitsgemeinschaft für Osteosynthesefragen (AO\\/ASIF) therefore designed a new intramedullary device, the proximal femoral nail (PFN), which during a handling study was tested in 4 European

R. K. J Simmermacher; A. M Bosch; Chr Van der Werken

1999-01-01

309

Interlaminated ice-proximal glacimarine sediments in Muir Inlet, Alaska  

USGS Publications Warehouse

Muir Inlet in Glacier Bay, Alaska, is a glacial fjord receiving a tremendous volume of sediment annually. The rate of sediment accumulation is greatest proximal to Muir Glacier (about 9 m yr-1) and decreases away from the glacier. The primary sediment sources are meltwater streams discharging at subglacial and ice-marginal positions to form overflows, interflows, and underflows (continuous turbidity currents). Overflows and interflows interact with diurnal tidal currents and their volume and sediment concentration varies diurnally and annually with meltwater discharge. These effects produce cyclic deposits of a thin fine-grained sand or silt lamina that grades normally to a thicker poorly to very poorly sorted mud lamina. This lamina couplet is termed a cyclopel. Underflows are suggested to occur in this glacimarine environment because of conditions unique to subglacial fluvial systems. Underflow deposits occur only in proximal positions (177 ??m) is ubiquitous, though low (<5% by weight), and occurs as isolated particles, frozen pellets, or as lenses that in cores may have a lamina appearance. Proximally, ice-rafted debris is difficult to identify because proximal sediment is often as coarse-grained. Deposited sediment may be reworked by tidal currents, and sediment gravity flows. Depositional processes operating in Muir Inlet produce interlaminated sand/silt/clay that characterizes sediment proximal to a glacier and fines seaward to mud. Sediment is classified into one of three sediment types: 1. (1) Type I sediment is very fine grained (mean 8.65-7.17 ??), low in sand (0.1-11.2%), and very poorly to poorly sorted. It is the dominant sediment type in Muir Inlet, and is transported by plumes and deposited by suspension settling. 2. (2) Type II sediment is fine- to coarse-grained (mean 6.70-3.12 ??), low to high in sand (5.1-86.6%), and very poorly to moderately sorted. It represents reworked sediment, proximal plume deposits, or coarse-grained laminae of cyclopels. 3. (3) Type III sediment is coarse-grained (mean 3.89-2.38 ??), high in sand (58.0-100.0%), and poorly to well sorted. It is deposited by sediment gravity flows or underflows. ?? 1984.

Mackiewicz, N. E.; Powell, R. D.; Carlson, P. R.; Molnia, B. F.

1984-01-01

310

Ulnar neuropathy with prominent proximal Martin-Gruber anastomosis.  

PubMed

Martin-Gruber anastomosis (MGA) is the most common nerve anastomosis in the upper extremities and it crosses from the median nerve to the ulnar nerve. Proximal MGA is an under recognized anastomosis between the ulnar and median nerves at or above the elbow and should not be missed during nerve conduction studies. We presented two patients with ulnar neuropathy mimicking findings including numbness and tingling of the 4th and 5th digits and mild weakness of intrinsic hand muscles. However, both cases had an apparently remarkable conduction block between the below- and above-elbow sites that was disproportionate to their clinical findings. To explain this discrepancy, a large MGA was detected with stimulation of the median nerve at the elbow. Thus, proximal MGA should be considered in ulnar neuropathy at the elbow when apparent conduction block or/and discrepancy between clinical and electrodiagnostic findings is found. PMID:24147570

Burakgazi, Ahmet Z; Russo, Mary; Bayat, Elham; Richardson, Perry K

2014-07-01

311

Optical rule checking for proximity-corrected mask shapes  

NASA Astrophysics Data System (ADS)

Optical Rule Checking (ORC) is an important vehicle to predict the failure of wafer shapes due to the process proximity effects. Optical Proximity Correction (OPC) if not aided by ORC may cause severe failures affecting the yield in manufacturing. However, it is fairly complicated to do ORC on mask shapes that are pre-corrected either by rules-based or by model-based OPC. ORC is also a good tool to capture the problems that may occur at multi-layer interactions. We present a methodology to use both geometric directives and limited optical simulation to detect potential failures using ORC. We extend our methodology to multi-layer interactions. In case of multi-layer ORC, we present several approaches that deal with how to judiciously mix the geometric directives and the optical simulations for different layers. We show the ORC can help us design better rules for OPC.

Mukherjee, Maharaj; Baum, Zachary; Nickel, John; Dunham, Timothy G.

2003-06-01

312

Rendezvous and Proximity Operations of the Space Shuttle  

NASA Technical Reports Server (NTRS)

Space Shuttle rendezous missions presented unique challenges that were not fully recognized when the Shuttle was designed. Rendezvous targets could be passive (i.e., no lights or transponders), and not designed to facilitate Shuttle rendezvous, proximity operations and retrieval. Shuttle reaction control system jet plume impingement on target spacecraft presented induced dynamics, structural loading and contamination concerns. These issues, along with limited forward reaction control system propellant, drove a change from the Gemimi/Apollo coelliptic profile heritage to a stable orbit profile, and the development of new proximity operations techniques. Multiple scientific and on-orbit servicing missions and crew exchange, assembly and replinishment flights to Mir and to the International Space Station drove further profile and piloting technique changes, including new relative navigation sensors and new computer generated piloting cues.

Goodman, John L.

2005-01-01

313

Bilateral spontaneous inter-trochanteric fractures of proximal femurs  

PubMed Central

INTRODUCTION Bilateral spontaneous inter-trochanteric fractures of the proximal femur are rare. We report an unusual case of bilateral intertrochanteric fractures of the proximal femur in a 92 year old lady. PRESENTATION OF CASE A 92 year old lady presented to us with one week history of pain in both hips and poor mobilisation. There was no history of mechanical fall. The initial plain films of the hips did not show any fractures and the diagnosis was made by MRI scans. She underwent bilateral fixation of the fractures with dynamic hip screws. After a period of rehabilitation she returned to the pre injury mobilisation status. DISCUSSION Bilateral spontaneous intertrochanteric fractures of the hip due to osteoporosis are not that common. These rare fractures are usually associated with major trauma, renal disease, osteoporosis, osteomalacia, long term corticosteroid treatment and epilepsy. CONCLUSION Early diagnosis with high index of suspicion and appropriate investigations are mandatory in the management of these fractures.

Rajeev, Aysha

2014-01-01

314

Longitudinal proximity effects in superconducting transition-edge sensors.  

PubMed

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{c} of the TES is current dependent and at fixed current scales as 1/L{2}. We have also 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 microm, 1450 times the mean-free path. PMID:20366733

Sadleir, John E; Smith, Stephen J; Bandler, Simon R; Chervenak, James A; Clem, John R

2010-01-29

315

Proximity Effect in Electron-Doped Cuprate Josephson junctions  

NASA Astrophysics Data System (ADS)

We study the proximity effect in Josephson junctions made from electron-doped high-Tc cuprates Pr2-xCexCuO4 (PCCO) as the electrodes and the barrier. For the electrodes, we use superconducting optimally doped PCCO (x = 0.15). PCCO x = 0.05, an antiferromagnetic metal, is used for the barrier. Our results demonstrate: 1) a conventional proximity effect; 2) but a coupling even if the barrier is antiferromagnetic. We determine the normal coherence length, ?n, which quantifies the extent of the pair wavefunction into the metal. Comparing this value with the theoretical expectations, we confirm that the coupling appears to be conventional through PCCO x = 0.05. Further results investigating the coupling through an insulating antiferromagnetic barrier and through a metal with no antiferromagnetic order will also be presented.

Charpentier, S.; Roberge, G.; Godin-Proulx, S.; Fournier, P.

2010-03-01

316

Proximity effect in electron-doped cuprate Josephson junctions  

NASA Astrophysics Data System (ADS)

We study the proximity effect in Josephson junctions made of electron-doped cuprates Pr2-xCexCuO4 (PCCO). With superconducting electrodes at a fixed doping x = 0.15, we explore the variation of the Josephson coupling with the doping and the thickness of the barrier. We observe Josephson coupling for any type of barrier: antiferromagnetic (AF) metal, AF insulator, or paramagnetic metal. For an x = 0.05 barrier, we can estimate the normal coherence length, ?n = 12 +/- 3 nm. Comparing this value with the theoretical prediction, ?n,max = 4.5 nm, we conclude that the proximity effect through a barrier of PCCO x = 0.05 is stronger than expected.

Charpentier, S.; Roberge, G.; Godin-Proulx, S.; Fournier, P.

2011-07-01

317

Proximity potential for heavy ion reactions on deformed nuclei  

SciTech Connect

The usual treatment of the deformed optical model for analysis of heavy ion induced inelastic scattering data involves a deformed (target) radius, a spherical (projectile) radius and a potential strength dependent on the surface separation along the line between the two centers. Several authors using various approaches have shown that this center line potential is geometrically inadequate especially for description of higher L deformation parameters probed in heavy ion induced inelastic scattering experiments. A quantitatively adequate form of the deformed proximity potential suitable for use with a coupled channels reaction code in the analysis of inelastic scattering data above the Coulomb barrier is described. A major objective is to be able to extract reliably higher deformed multipole moments from such data. The deformed potential calculated in the folding model will serve as a geometrically exact benchmark to evaluate the accuracy of the proximity potential prescriptions. (WHK)

Baltz, A.J.; Bayman, B.F.

1982-01-01

318

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.

1987-01-01

319

Fatigue testing of a proximal femoral hip component.  

PubMed

The Gothenburg Osseointegrated Titanium (GOT) implant is a novel total hip replacement including a metaphyseal loading proximal femoral component fixed in the retained femoral neck. Endurance testing was performed under conditions analogous to ISO 7206-4: 1989. The cement-free implant is not fixed distally within the intramedullary canal, so distal embedding (as specified in the standard) would have been unrealistic. Instead glass-fibre-reinforced epoxy (GFRE) bushings were used to model reduced bone support mid-length at the medial cortex and distally at the lateral cortex. Such support simulated proximal bone loss, realistically reproducing the effect of osteolysis or fixation failure. Under such conditions the component survived unbroken for 10 million cycles at 3.0 kN peak load. PMID:12666781

Macdonald, W; Carlsson, L V; Gathercole, N; Jacobsson, C M

2003-01-01

320

Scintillation proximity radioimmunoassay utilizing 125I-labeled ligands  

SciTech Connect

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.

1985-12-01

321

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.

2009-01-01

322

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.

2009-01-01

323

Elements of proximal formative assessment in learners' discourse about energy  

NSDL National Science Digital Library

Proximal formative assessment, the just-in-time elicitation of students' ideas that informs ongoing instruction, is usually associated with the instructor in a formal classroom setting. However, the elicitation, assessment, and subsequent instruction that characterize proximal formative assessment are also seen in discourse among peers. We present a case in which secondary teachers in a professional development course at SPU are discussing energy flow in refrigerators. In this episode, a peer is invited to share her thinking (elicitation). Her idea that refrigerators move heat from a relatively cold compartment to a hotter environment is inappropriately judged as incorrect (assessment). The "instruction" (peer explanation) that follows is based on the second law of thermodynamics, and acts as corrective rather than collaborative.

Harrer, Benedikt W.; Scherr, Rachel E.; Wittmann, Michael C.; Close, Hunter G.; Frank, Brian W.

2012-05-15

324

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.

2010-01-01

325

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.

326

Locality of information obtained from proximity-electron-tunneling spectroscopy  

SciTech Connect

The locality of the information obtained by the technique of proximity-electron tunneling (PETS) is analyzed, with particular attention to the effects on the measured effective-phonon spectrum ..cap alpha../sup 2/F(..omega..) is disorder or impurities near the surface of the superconductor electrode. As in conventional tunnel junctions it is determined that the (energy-dependent) electron mean free path determines the maximum depth of the superconductor of which the measured phonon spectrum is characterized. An averaging length L(E) is defined and found to be typically larger in proximity junctions than in conventional junctions. This can make PET results inherently less susceptible than conventional results to surface disorder of the superconductor.

Arnold, G.B.; Wolf, E.L.

1982-02-01

327

Proximity-induced pseudogap: evidence for preformed pairs.  

PubMed

The temperature evolution of the proximity effect in Au/La(2-x)Sr(x)CuO(4) and La(1.55)Sr(0.45)CuO(4)/La(2-x)Sr(x)CuO(4) bilayers was investigated using scanning tunneling microscopy. Proximity-induced gaps, centered at the chemical potential, were found to persist above the superconducting transition temperature, T(c), and up to nearly the pseudogap crossover temperature in both systems. Such independence of the spectra on the details of the normal-metal cap layer is incompatible with a density-wave order origin. However, our results can be accounted for by a penetration of incoherent Cooper pairs into the normal metal above T(c). PMID:20365947

Yuli, Ofer; Asulin, Itay; Kalcheim, Yoav; Koren, Gad; Millo, Oded

2009-11-01

328

Magnetic Insulators-Induced Proximity Effects in Graphene  

NASA Astrophysics Data System (ADS)

Due to its very long spin diffusion lengths up to room temperature, emergence of magnetism in graphene has attracted a lot of research interest in the field of spintronics. Several methods have been proposed to magnetize graphene, from edge magnetism, to depositing magnetic atoms or molecules, and using ferromagnetic substrate. We present first-principles calculations of spin-dependent properties in graphene induced by its interaction with ferromagnetic insulator EuO, and show that this proximity effect results in spin polarization of graphene ? orbitals by up to 24% together with large exchange splitting bandgap of about 36 meV. Moreover, the position of the Dirac cone is shown to depend strongly on the graphene-EuO interlayer distance. These findings pave the way towards the possible engineering of graphene spin gating by proximity effect especially in a view of recent experiments on successful growth of Europium oxide on top of graphene.

Hallal, Ali; Yang, Hongxin; Terrade, Damien; Waintal, Xavier; Roche, Stephan; Chshiev, Mairbek

2013-03-01

329

Just-in-Time Manufacturing Systems, Subcontracting and Geographic Proximity  

Microsoft Academic Search

Holl A., Pardo R. and Rama R. Just-in-Time manufacturing systems, subcontracting and geographic proximity, Regional Studies. The paper studies the spatial extent of subcontracting linkages for a sample of medium-sized and large Spanish manufacturing firms operating in the automotive and electronics industries. In particular, it analyses how Just-in-Time (JIT) organization of production is related to the spatial pattern of these

Adelheid Holl; Rafael Pardo; Ruth Rama

2010-01-01

330

Proximity Drawings: Three Dimensions Are Better than Two  

Microsoft Academic Search

We consider weak Gabriel drawings of unbounded degree trees in the three-dimensional space. We assume a minimum distance between\\u000a any two vertices. Under the same assumption, there exists an exponential area lower bound for general graphs. Moreover, all\\u000a previously known algorithms to construct (weak) proximity drawings of trees, generally produce exponential area layouts, even\\u000a when we restrict ourselves to binary

Paolo Penna; Paola Vocca

1998-01-01

331

High-Energy Proximal Femur Fractures in Geriatric Patients  

PubMed Central

Background: There is limited information in the literature on the outcomes and complications in elderly patients who sustain high-energy hip fractures. As the population ages, the incidence of high-energy geriatric hip fractures is expected to increase. The purpose of this study was to analyze the outcomes and complications in patients aged 65 years or older, who sustained a high-energy proximal femur fracture. Methods: Retrospective review of a prospective trauma database from January 2000 to April 2011 at a single US academic level-1 trauma center. Inclusion criteria consisted of all patients of age 65 years or older, who sustained a proximal femur fracture related to a high-energy trauma mechanism. Details concerning injury, acute treatment, and clinical course and outcome were obtained from medical records and radiographs. Results: We identified 509 proximal femur fractures in patients older than 65 years of age, of which 32 (6.3%) were related to a high-energy trauma mechanism. The mean age in the study group was 72.2 years (range 65-87), with a mean injury severity score of 20 points (range 9-57). Three patients died before discharge (9.4%), and 22 of 32 patients sustained at least one complication (68.8%). Blunt chest trauma represented the most frequently associated injury, and the main root cause of pulmonary complications. The patients' age and comorbidities did not significantly correlate with the rate of complications and the 1-year mortality. Conclusions: High-energy proximal femur fractures in elderly patients are not very common and are associated with a low in-hospital mortality rate of less than 10%, despite high rate of complications of nearly 70%. This selective cohort of patients requires a particular attention to respiratory management due to the high incidence of associated chest trauma.

Hahnhaussen, Jens; Hak, David J; Weckbach, Sebastian; Ertel, Wolfgang; Stahel, Philip F

2011-01-01

332

Micro-antenna design for intra-cortical proximity communication  

Microsoft Academic Search

This paper discusses the antenna design considerations for intra-cortical proximity communication. The performances of microstrip patch and monopole antenna systems at 60 GHz have been compared. The monopole antenna system can potentially bring down the power required for brain-machine interface technology to micro-watt level. The receiving power can be significantly improved and meet the sensitivity level of the conventional receivers

Kin-Fai Tong; Terrence Mak; Jordan Ivanchev

2011-01-01

333

Subcoracoid trapping of the proximal fragment of a fractured clavicle.  

PubMed

An unusual indication--not previously reported--for surgical treatment of a clavicle fracture, in a 56-year-old male, is presented. The proximal fragment had been entrapped under the coracoid, and there were symptoms from impairment of the musculocutaneous nerve. Reduction by closed means proved unsuccessful, and an open procedure was necessary for this rare type of the common clavicle fracture. PMID:9253928

Kontakis, G M; Katonis, P G

1997-07-01

334

Complex of myoglobin with phenol bound in a proximal cavity.  

PubMed

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

2012-12-01

335

Metacognition of agency: proximal action and distal outcome.  

PubMed

The cues contributing to people's metacognitions of agency were investigated in two experiments in which people played a computer game that involved trying to "touch", via a mouse moving a cursor, downward scrolling X's (Experiment 1), or trying to "explode" the downward scrolling X's (Experiment 2). Both experiments varied (a) proximal action-related information by either introducing or not introducing Turbulence into the mouse controls and (b) distal outcome-related information such that touched X's "exploded" either 100 or 75 % of the time. Both variables affected people's judgments of agency (JOAs), but the effect was different. First, the decrement in feelings of agency was greater with the proximal variable than with distal variable. Second, while the proximal variable always had a large direct effect on JOAs, even taking judgments of performance (JOPs) into account, JOPs completely accounted for the effect of the distal variable in Experiment 1, where the instructions were just to touch the X's. And even in Experiment 2, in which the instructions were to explode the X's, the direct effect of the distal variable on JOAs was small. These data indicate that these two cues exhibit different psychological profiles. The proximal action-related information is a diagnostic cue to agency indicating the match between one's own intentions and actions. Internal monitoring of intentions is necessary and so the self is implicated. However, distal outcome can be largely monitored using information external to the agent, and so-while it is used by people to make agency judgments-it is a non-diagnostic cue. PMID:23358706

Metcalfe, Janet; Eich, Teal S; Miele, David B

2013-09-01

336

Improvement of Negative Bias Temperature Instability by Stress Proximity Technique  

Microsoft Academic Search

The stress proximity technique (SPT) is found to improve negative bias temperature instability (NBTI) in p-channel metal-oxide-semiconductor field-effect transistors significantly. A first-principles calculation is carried out to examine the effect of strain on NBTI, and a process simulation is conducted to determine the change in stress profile in the device induced by SPT. The first-principles calculation shows that a larger

Jian Bo Yang; T. P. Chen; Ying Gong; Shyue Seng Tan; Chee Mang Ng; Lap Chan

2010-01-01

337

Involvement of the proximal tibial epiphysis by monostotic fibrous dysplasia  

Microsoft Academic Search

We report a case of monostotic fibrous dysplasia (FD) solely demonstrating epiphyseal lesion. A 13-year-old boy was referred to our hospital complaining of pain in his left knee joint. Plain radiographs showed an osteolytic lesion with slightly sclerotic margin at the proximal epiphysis of the left tibia. The lesion was shown with low intensity on T1-weighted and high on T2*-weighted

Rumi Takechi; Tetsuya Shinozaki; Toshio Fukuda; Takashi Yanagawa; Kenji Takagishi

2009-01-01

338

Techniques for intramedullary nailing of proximal tibia fractures.  

PubMed

Despite poor early results with intramedullary nailing of extra-articular proximal tibia fractures, improvements in surgical technique and implant design modifications have resulted in more acceptable outcomes. However, prevention of the commonly encountered apex anterior and/or valgus deformities remains a challenge when treating these injuries. It is necessary for the surgeon to recognize this and know how to neutralize these forces. Surgeons should be comfortable using a variety of the reduction techniques presented to minimize fracture malalignment. PMID:24267205

Stinner, Daniel J; Mir, Hassan

2014-01-01

339

Gastrojejunostomy for management of acute proximal enteritis in a horse.  

PubMed

A 5-year-old Arabian stallion was treated medically 6 days for proximal enteritis. On the sixth day, exploratory celiotomy verified the diagnosis and ruled out other intraluminal and extraluminal gastrointestinal tract obstructions. A gastrojejunostomy was performed. The horse had trouble maintaining and gaining weight in the first year after surgery, but 8 years after surgery, the owner reported that the horse was doing well. PMID:8163421

Gillis, J P; Taylor, T S; Puckett, M J

1994-02-15

340

A Tripolarization Antenna Fed by Proximity Coupling and Probe  

Microsoft Academic Search

The design and characterization of a conformal tripolarization antenna with three independent ports and three orthogonal polarizations is presented. The antenna uses both proximity (slot) coupling and probe-fed ports to reduce isolation and improve polarization purity. The measured bandwidth of the -10-dB return loss is found to be 190 MHz (2.4-2.59 GHz). Measurements across the working bandwidth also show that

Hua Zhong; Zhijun Zhang; Wenhua Chen; Zhenghe Feng; Magdy F. Iskander

2009-01-01

341

The 3-D guidance system with proximity sensors  

NASA Technical Reports Server (NTRS)

Four proximity sensors help to guide mechanical claw into alinement with target fixture. Digital signals are used to sense distance and to aline roll, pitch, and yaw with respect to target before it is grasped. Sixteen sensor-to-operator messages are possible with binary signal system. Similar, more precise alternative presents 75 workable logic states; most precise alternative uses continuous calibrated data from sensors.

Bejczy, A. K.

1980-01-01

342

Proximity Graphs for Defining Surfaces over Point Clouds  

Microsoft Academic Search

a b c d Visualization of the moving least squares surface (magenta) over a 2D point cloud (black dots) based on different distance functions: (a,c) Euclidean, (b,d) ours based on proximity graphs. We present a new definition of an implicit surface over a noisy point cloud. It can be evaluated very fast, but, unlike other definitions based on the moving

Jan Klein; Gabriel Zachmann

2004-01-01

343

Towards Core Body Temperature Measurement via Close Proximity Radiometric Sensing  

Microsoft Academic Search

Presented is a noncontact model and radiometric sensor developed to facilitate core body temperature extraction. The system has been designed as a close-proximity sensor to detect thermal emissions radiated from deep inside the human body. The radiometer uses a cavity-backed slot antenna (CBSA) designed to account for performance degradation which occurs in the near field of the human body. Tissue-simulating

Quenton Bonds; John Gerig; Thomas M. Weller; Paul Herzig

2012-01-01

344

Interlanguage pragmatics in the zone of proximal development  

Microsoft Academic Search

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 Higher Psychological Processes. Harvard University Press, Cambridge, MA], and definitions are queried

Amy Snyder Ohta

2005-01-01

345

CD28 proximal promoter polymorphisms in systemic lupus erythematosus susceptibility.  

PubMed

CD28 expression and serum levels are significantly increased in patients with SLE than in healthy controls (HC). Until now, there are no studies of proximal promoter polymorphisms of CD28 gene in SLE. Therefore, our objective was to investigate the polymorphisms present in the proximal promoter of CD28 in a group of SLE and HC and to associate the polymorphisms present with the CD28 serum levels of 40 patients and 40 controls. One hundred and seven patients as well as 108 controls matched by age range and genders were included. The 11 ACR criteria were analyzed on the clinical files, and the proximal promoter region of CD28 gene was analyzed by direct sequencing of a 489-basepair fragment. C28 serum levels (sCD28) were measured by ELISA technique in 40 patients and 40 controls. Only two of the eight reported polymorphisms were found, and they correspond to rs35593994 (-372 A/G) and rs56156157 (-145 -/C). The first had a prevalence of 41 and 36% in patients and controls respectively and the second of 1.4% in both groups. None of these polymorphisms were associated with SLE, and the polymorphism -372 A/G was not associated with the clinical features of disease. Likewise, the association with the sCD28 and the genotypes of -372 A/G polymorphism was not significant. The polymorphisms of the proximal promoter of CD28 are not associated with SLE, and the polymorphism -372 A/G is not associated with the diagnostic criteria of SLE or the sCD28. PMID:21544637

Brambila-Tapia, Aniel Jessica Leticia; Dávalos-Rodríguez, Ingrid P; Gámez-Nava, Jorge Iván; González-López, Laura; Medina-Díaz, Julio; Bernard-Medina, Ana Guilaisne; Salazar-Páramo, Mario

2012-07-01

346

Isolated anterior dislocation of the proximal tibiofibular joint.  

PubMed

Three cases of isolated anterior dislocation in the proximal tibiofibular joint are presented. The common aetiological feature was that injury occurred with the knee in hyperflexion and the foot inverted and extended. The symptoms of locking, pain and giving way may lead to an erroneous diagnosis of meniscal injury. Early diagnosis in the acute case enabled easy reduction. In the inveterate cases, resection of the head of the fibula gave complete relief of symptoms. PMID:6841401

Falkenberg, P; Nygaard, H

1983-05-01

347

Thermal Conductance by the Inverse Proximity Effect in a Superconductor  

NASA Astrophysics Data System (ADS)

We study heat transport in hybrid lateral normal-metal-superconductor-normal-metal structures. We find the thermal conductance of a short superconducting wire to be strongly enhanced beyond the BCS value due to the inverse proximity effect, resulting from contributions of elastic cotunneling and crossed Andreev reflection of quasiparticles. Our measurements agree with a model based on the quasiclassical theory of inhomogeneous superconductivity in the diffusive limit.

Peltonen, J. T.; Virtanen, P.; Meschke, M.; Koski, J. V.; Heikkilä, T. T.; Pekola, J. P.

2010-08-01

348

Spin-polarized proximity effect in superconducting junctions  

NASA Astrophysics Data System (ADS)

We study spin dependent phenomena in superconducting junctions in both ballistic and diffusive regimes. For ballistic junctions we study both ferromagnet/ s- and d-wave superconductor junctions and two-dimensional electron gas/ s-wave superconductor junctions with Rashba spin-orbit coupling. It is shown that the exchange field always suppresses the conductance while the Rashba spin-orbit coupling can enhance it. In the latter part of the article we study the diffusive ferromagnet/insulator/ s- and d-wave superconductor (DF/I/S) junctions, where the proximity effect can be enhanced by the exchange field in contrast to common belief. This resonant proximity effect in these junctions is studied for various situations: conductance of the junction and density of states of the DF are calculated by changing the heights of the insulating barriers at the interfaces, the magnitudes of the resistance in DF, the exchange field in DF, the transparencies of the insulating barriers and the angle between the normal to the interface and the crystal axis of d-wave superconductors ?. It is shown that the resonant proximity effect originating from the exchange field in DF strongly influences the tunneling conductance and density of states. We clarify the followings: for s-wave junctions, a sharp zero bias conductance peak (ZBCP) appears due to the resonant proximity effect. The magnitude of this ZBCP can exceed its value in normal states in contrast to that observed in diffusive normal metal/superconductor junctions. We find similar structures to the conductance in the density of states. For d-wave junctions at ?=0, we also find a result similar to that in s-wave junctions. The magnitude of the resonant ZBCP at ?=0 can exceed that at ?/?=0.25 due to the formation of the mid gap Andreev resonant states. To cite this article: T. Yokoyama, Y. Tanaka, C. R. Physique 7 (2006).

Yokoyama, Takehito; Tanaka, Yukio

2006-01-01

349

Hydatid disease at the proximal end of the clavicle  

Microsoft Academic Search

.  ?We report a case of hydatid disease at the proximal end of the clavicle of a 47-year-old woman. In an open biopsy, laminated\\u000a layers, characteristic of Echinococcus multilocularis larvae, were revealed by periodic acid-Schiff (PAS) staining. A marked foreign-body reaction was observed in the pathological\\u000a findings. The patient was definitely diagnosed as having osseous hydatid disease. We performed resection of

Masayuki Takakuwa; Masatoshi Katsuki; Takeo Matsuno; Takakazu Hirayama; Eiji Yoshida

2002-01-01

350

Proximate sources of population sex imbalance in india  

Microsoft Academic Search

There is a population sex imbalance in India. Despite a consensus that this imbalance is due to excess female mortality, the\\u000a specific source of this excess mortality remains poorly understood. I use microdata on child survival in India to analyze\\u000a the proximate sources of the sex imbalance. I address two questions: when in life does the sex imbalance arise, and

Emily Osters

2009-01-01

351

Thermal conductance by the inverse proximity effect in a superconductor.  

PubMed

We study heat transport in hybrid lateral normal-metal-superconductor-normal-metal structures. We find the thermal conductance of a short superconducting wire to be strongly enhanced beyond the BCS value due to the inverse proximity effect, resulting from contributions of elastic cotunneling and crossed Andreev reflection of quasiparticles. Our measurements agree with a model based on the quasiclassical theory of inhomogeneous superconductivity in the diffusive limit. PMID:20868187

Peltonen, J T; Virtanen, P; Meschke, M; Koski, J V; Heikkilä, T T; Pekola, J P

2010-08-27

352

Acoustic proximity ranging and its applications to cavity thickness monitoring  

Microsoft Academic Search

Time-of-flight (ToF) based acoustic proximity ranging is widely used in many applications. In this dissertation, its applications to cavity thickness monitoring of a supercavitating vehicle are studied. Most of the currently available ToF based acoustic ranging systems are not directly applicable to this case due to their low measurement accuracy and low parameter update rate. New measurement schemes and the

Xi Li

2003-01-01

353

Model calculations of the proximity effect in finite multilayers  

Microsoft Academic Search

The proximity-effect theory developed by Takahashi and Tachiki for infinite superconductor\\/normal (S\\/N) multilayers is applied to multilayer systems with a finite number of layers in the growth direction. The purpose is to investigate why previous applications to infinite multilayers fail to describe the measured data satisfactorily. It is shown that surface superconductivity may appear, depending on the thickness of the

C. Ciuhu; A. Lodder

2001-01-01

354

Specific Cre\\/Lox Recombination in the Mouse Proximal Tubule  

Microsoft Academic Search

The present work reports for the first time the con- struction of a transgenic mouse strain with specific expression of Cre recombinase in the kidney proximal tubule. A Cre\\/loxP strategy was developed using sglt2 promoter to drive Cre recombinase expression in transgenic mice. The mouse sglt2 5' region consisting of the first exon, the first intron, and part of the

ISABELLE RUBERA; CHANTAL POUJEOL; GUILLAUME BERTIN; LILIA HASSEINE; LAURENT COUNILLON; PHILIPPE POUJEOL; MICHEL TAUC

2004-01-01

355

Anomalous proximity effect in an inhomogeneous disordered superconductor.  

PubMed

By combining very low temperature scanning tunneling microscopy and spectroscopy on a TiN film we have observed a nonuniform state comprising of superconducting (S) and normal (N) areas. The local density of states displays a spatial dependence between S and N different from the usual proximity effect. We conclude that mesoscopic fluctuations might play a major role in accordance with recent theories describing superconductor-normal-metal quantum transition. PMID:15601055

Escoffier, W; Chapelier, C; Hadacek, N; Villégier, J-C

2004-11-19

356

Self Organizing Map and Sammon Mapping for Asymmetric Proximities  

Microsoft Academic Search

Self Organizing Maps (SOM) and Sammon Mapping (SM) are two information visualization techniques widely used in the data mining\\u000a community. These techniques assume that the similarity matrix for the data set under consideration is symmetric. However there\\u000a are many interesting problems where asymmetric proximities arise, like text mining problems are. In this work we propose modified\\u000a versions of SOM and

Manuel Martín-merino; Alberto Muñoz

2001-01-01

357

Biomechanics and anatomy of the proximal biceps tendon.  

PubMed

With the role of the biceps tendon being the source of considerable controversy, the treatment of its disease has been even more confusing. Our understanding of its role in shoulder pathology has ranged from describing it as a vestigial structure, to a vital structure of shoulder function with distinct disease pathology. This chapter analyzes the anatomic and biomechanical functions of the proximal biceps tendon. PMID:18703968

Bicos, James

2008-09-01

358

Acute renal proximal tubule alterations during induced metabolic crises in a mouse model of glutaric aciduria type 1.  

PubMed

The metabolic disorder glutaric aciduria type 1 (GA1) is caused by deficiency of the mitochondrial glutaryl-CoA dehydrogenase (GCDH), leading to accumulation of the pathologic metabolites glutaric acid (GA) and 3-hydroxyglutaric acid (3OHGA) in blood, urine and tissues. Affected patients are prone to metabolic crises developing during catabolic conditions, with an irreversible destruction of striatal neurons and a subsequent dystonic-dyskinetic movement disorder. The pathogenetic mechanisms mediated by GA and 3OHGA have not been fully characterized. Recently, we have shown that GA and 3OHGA are translocated through membranes via sodium-dependent dicarboxylate cotransporter (NaC) 3, and organic anion transporters (OATs) 1 and 4. Here, we show that induced metabolic crises in Gcdh(-/-) mice lead to an altered renal expression pattern of NaC3 and OATs, and the subsequent intracellular GA and 3OHGA accumulation. Furthermore, OAT1 transporters are mislocalized to the apical membrane during metabolic crises accompanied by a pronounced thinning of proximal tubule brush border membranes. Moreover, mitochondrial swelling and increased excretion of low molecular weight proteins indicate functional tubulopathy. As the data clearly demonstrate renal proximal tubule alterations in this GA1 mouse model during induced metabolic crises, we propose careful evaluation of renal function in GA1 patients, particularly during acute crises. Further studies are needed to investigate if these findings can be confirmed in humans, especially in the long-term outcome of affected patients. PMID:23623985

Thies, Bastian; Meyer-Schwesinger, Catherine; Lamp, Jessica; Schweizer, Michaela; Koeller, David M; Ullrich, Kurt; Braulke, Thomas; Mühlhausen, Chris

2013-10-01

359

Proximity interactions among centrosome components identify regulators of centriole duplication.  

PubMed

The centrosome consists of a pair of centrioles and surrounding pericentriolar material (PCM). Many vertebrate cells also have an array of granules, termed centriolar satellites, that localize around the centrosome and are associated with centrosome and cilium function. Centriole duplication occurs once per cell cycle and is effected by a set of proteins including PLK4, CEP192, CEP152, CEP63, and CPAP. Information on the relationships between these components is limited due to the difficulty in assaying interactions in the context of the centrosome. Here, we used proximity-dependent biotin identification (BioID) to identify proximity interactions among centriole duplication proteins. PLK4, CEP192, and CEP152 BioID identified known physically interacting proteins and a new interaction between CEP152 and CDK5RAP2 consistent with a function of CEP152 in PCM recruitment. BioID for CEP63 and its paralog CCDC67 revealed extensive proximity interactions with centriolar satellite proteins. Focusing on these satellite proteins identified two new regulators of centriole duplication, CCDC14 and KIAA0753. Both proteins colocalize with CEP63 to satellites, bind to CEP63, and identify other satellite proteins by BioID. KIAA0753 positively regulates centriole duplication and CEP63 centrosome localization, whereas CCDC14 negatively regulates both processes. These results suggest that centriolar satellites have a previously unappreciated function in regulating centriole duplication. PMID:24613305

Firat-Karalar, Elif Nur; Rauniyar, Navin; Yates, John R; Stearns, Tim

2014-03-17

360

Proximate and phytochemical of Cola nitida and Cola acuminata.  

PubMed

The aim of the research was to examine Cola nitida and Cola acuminata for their phytochemical and proximate compositions. Presence of secondary metabolites do provide information about the plants for their potentials as a lead candidates for the novel drug discovery. The proximate analysis was done using the method of Association of Official Analytical Chemists (AOAC) and the phytochemical analysis was done using methods of Markkar and Goodchild for tannin, Brunner for saponin, Harbone for alkaloid and Bohm and Koupai-Abyazani for flavonoid. The proximate results showed that the moisture content of Cola acuminata and Cola nitida were in the range of 9.73-9.81%, ash 2.72-2.21%, fat 3.02-2.20%, protein 19.14-15.24%, crude fiber 7.30-4.18% and carbohydrate 58.09 66.45%. Cola acuminate has more protein content, ash and fat than Cola nitida. The result of phytochemical analysis showed that Cola acuminata has more alkaloids (2.22%), tannin (6.46%) and saponin (8.06%) than Cola nitida. The phenol contents of the two kola nuts were the same range 0.27%, the flavonoid were in the range of 0.12-0.14%. The presence of secondary metabolites in these plants are indications that if well researched, novel bioactive compounds can be discovered in them as there are worldwide efforts by scientists looking for new bioactive compounds to combat various ailments which have developed high resistant to already known antibiotics. PMID:24511707

Dewole, E A; Dewumi, D F A; Alabi, J Y T; Adegoke, A

2013-11-15

361

PRIM: Proximity imaging of green fluorescent protein-tagged polypeptides  

PubMed Central

We report a serendipitous discovery that extends the impressive catalog of reporter functions performed by green fluorescent protein (GFP) or its derivatives. When two GFP molecules are brought into proximity, changes in the relative intensities of green fluorescence emitted upon excitation at 395 vs. 475 nm result. These spectral changes provide a sensitive ratiometric index of the extent of self-association that can be exploited to quantitatively image homo-oligomerization or clustering processes of GFP-tagged proteins in vivo. The method, which we term proximity imaging (PRIM), complements fluorescence resonance energy transfer between a blue fluorescent protein donor and a GFP acceptor, a powerful method for imaging proximity relationships between different proteins. However, unlike fluorescence resonance energy transfer (which is a spectral interaction), PRIM depends on direct contact between two GFP modules, which can lead to structural perturbations and concomitant spectral changes within a module. Moreover, the precise spatial arrangement of the GFP molecules within a given dimer determines the magnitude and direction of the spectral change. We have used PRIM to detect FK1012-induced dimerization of GFP fused to FK506-binding protein and clustering of glycosylphosphatidylinositol-anchored GFP at cell surfaces.

De Angelis, Dino A.; Miesenbock, Gero; Zemelman, Boris V.; Rothman, James E.

1998-01-01

362

PRIM: proximity imaging of green fluorescent protein-tagged polypeptides.  

PubMed

We report a serendipitous discovery that extends the impressive catalog of reporter functions performed by green fluorescent protein (GFP) or its derivatives. When two GFP molecules are brought into proximity, changes in the relative intensities of green fluorescence emitted upon excitation at 395 vs. 475 nm result. These spectral changes provide a sensitive ratiometric index of the extent of self-association that can be exploited to quantitatively image homo-oligomerization or clustering processes of GFP-tagged proteins in vivo. The method, which we term proximity imaging (PRIM), complements fluorescence resonance energy transfer between a blue fluorescent protein donor and a GFP acceptor, a powerful method for imaging proximity relationships between different proteins. However, unlike fluorescence resonance energy transfer (which is a spectral interaction), PRIM depends on direct contact between two GFP modules, which can lead to structural perturbations and concomitant spectral changes within a module. Moreover, the precise spatial arrangement of the GFP molecules within a given dimer determines the magnitude and direction of the spectral change. We have used PRIM to detect FK1012-induced dimerization of GFP fused to FK506-binding protein and clustering of glycosylphosphatidylinositol-anchored GFP at cell surfaces. PMID:9770483

De Angelis, D A; Miesenböck, G; Zemelman, B V; Rothman, J E

1998-10-13

363

The significance of splenectomy for advanced proximal gastric cancer.  

PubMed

Objectives. The significance of splenectomy in advanced proximal gastric cancer is examined retrospectively. Methods. From 1994 to 2004, 505 patients with advanced proximal gastric cancer underwent curative total gastrectomy with preserving spleen (T) for 264 patients and total gastrectomy with splenectomy (ST) for 241 patients. Results. Patients who underwent splenectomy showed more advanced lesions. The metastatic rate of lymph node (LN) in the splenic hilus (No. 10) in ST was 18.3%. As for the incidence of surgical complications, there was not statistically difference except for pancreatic fistula. The index of estimated benefit of (No. 10) LN was 4.2, which was similar to that of (No. 9), (No. 11p), (No. 11d), and (No. 16) LNs. 5-year survival rate of (No. 10) positive group was 22.2%. 5-year survival rates of pSE and pN2 in T group were better than that of pSE and pN2 in ST, respectively. The superiority of ST was not confirmed even in Stage II, IIIA, and IIIB. Conclusion. Splenectomy was not effective for patients with (No. 10) metastasis in long-term survival. Spleen-preserving total gastrectomy will be feasible and be enough to accomplish radical surgery for locally advanced proximal gastric cancer. PMID:22685639

Nashimoto, Atsushi; Yabusaki, Hiroshi; Matsuki, Atsushi

2012-01-01

364

The proximal tubule in the pathophysiology of the diabetic kidney.  

PubMed

Diabetic nephropathy is a leading cause of end-stage renal disease. A better understanding of the molecular mechanism involved in the early changes of the diabetic kidney may permit the development of new strategies to prevent diabetic nephropathy. This review focuses on the proximal tubule in the early diabetic kidney, particularly on its exposure and response to high glucose levels, albuminuria, and other factors in the diabetic glomerular filtrate, the hyperreabsorption of glucose, the unique molecular signature of the tubular growth phenotype, including aspects of senescence, and the resulting cellular and functional consequences. The latter includes the local release of proinflammatory chemokines and changes in proximal tubular salt and fluid reabsorption, which form the basis for the strong tubular control of glomerular filtration in the early diabetic kidney, including glomerular hyperfiltration and odd responses like the salt paradox. Importantly, these early proximal tubular changes can set the stage for oxidative stress, inflammation, hypoxia, and tubulointerstitial fibrosis, and thereby for the progression of diabetic renal disease. PMID:21228342

Vallon, Volker

2011-05-01

365

Microalbuminuria and proximal tubule remodeling in the cardiometabolic syndrome.  

PubMed

Microalbuminuria is a simple screening test that is not only associated with an increased risk of progressive renal insufficiency, but also an increased risk of cardiovascular disease and stroke in the cardiometabolic syndrome. The role of oxidative stress, inflammation, and cellular-extracellular matrix remodeling fibrosis is very important, and the authors have previously observed that albuminuria is related, in part, to loss of the integrity of the glomerular filtration apparatus. The proximal tubule may play a more important role than previously thought, as it is estimated that in health this portion of the nephron reabsorbs 5-8 g of albumin that normally leaks through the glomerulus on a daily basis. Recently, the authors have made important preliminary observational findings regarding proximal tubule microvilli remodeling and oxidative stress, which may help to explain microalbuminuria. These observations suggest that albuminuria is associated with proximal tubule injury, as well as loss of integrity of the glomerular filtration barrier in association with obesity and insulin resistance. PMID:17679822

Hayden, Melvin R; Chowdhury, Nazif A; Witte, Lauren; Sowers, James R

2006-01-01

366

Isolated acute dislocation of the proximal tibiofibular joint.  

PubMed

Lesions of knee's lateral side are less common than medial injuries. The anatomy of the lateral ligaments and the presence of additional structures (eg, fibula head) can cause diagnostic problems. Isolated dislocation of the proximal tibiofibular joint is unusual; therefore, it may be overlooked in the emergency department. Many cases are missed due to failure of diagnosis. This type of injury is common in athletes whose sports require twisting motions of the flexed knee (eg, wrestling, parachute jumping, judo, gymnastics, skiing, rugby, football, soccer, track, baseball, basketball, racquetball, and roller-skating). Anterolateral dislocation of the proximal tibiofibular joint is seemingly rare in soccer players, as less than a handful cases have been reported in the literature. The diagnosis can be made by clinical examination, plain knee radiographs, and, sometimes, computed tomography (CT) scanning for further confirmation. Treatment usually consists of closed or open reduction. In complicated cases, however, arthrodesis or resection of the fibular head may be required. This article reports a rare case of acute isolated anterolateral dislocation of the proximal tibiofibular joint in a soccer player and discusses the joint anatomy, types of dislocations, mechanisms of injury, and treatment options. PMID:19292340

Iosifidis, Michael I; Giannoulis, Ioannis; Tsarouhas, Alexandros; Traios, Stavros

2008-06-01

367

Tyrosine phosphorylation profiling via in situ proximity ligation assay  

PubMed Central

Background Tyrosine phosphorylation (pTyr) is an important cancer relevant posttranslational modification since it regulates protein activity and cellular localization. By controlling cell growth and differentiation it plays an important role in tumor development. This paper describes a novel approach for detection and visualization of a panel of pTyr proteins in tumors using in situ proximity ligation assay. Methods K562 leukemia cells were treated with tyrosine kinase and/or phosphatase inhibitors to induce differences in pTyr levels and mimic cells with different malignant properties. Cells were then probed with one antibody against the pTyr modification and another probe against the detected protein, resulting in a detectable fluorescent signal once the probes were in proximity. Results Total and protein specific pTyr levels on ABL, SHC, ERK2 and PI3K proteins were detected and samples of control and treated cells were distinguished at the pTyr level using this novel approach. Promising results were also detected for formalin fixed and paraffin embedded cells in the micro array format. Conclusions This application of in situ proximity ligation assay is valuable in order to study the pTyr modification of a panel of proteins in large data sets to validate mass spectrometric data and to be combined with tissue microarrays. The approach offers new opportunities to reveal the pTyr signatures in cells of different malignant properties that can be used as biomarker of disease in the future.

2014-01-01

368

Automated induction of heterogeneous proximity measures for supervised spectral embedding.  

PubMed

Spectral embedding methods have played a very important role in dimensionality reduction and feature generation in machine learning. Supervised spectral embedding methods additionally improve the classification of labeled data, using proximity information that considers both features and class labels. However, these calculate the proximity information by treating all intraclass similarities homogeneously for all classes, and similarly for all interclass samples. In this paper, we propose a very novel and generic method which can treat all the intra- and interclass sample similarities heterogeneously by potentially using a different proximity function for each class and each class pair. To handle the complexity of selecting these functions, we employ evolutionary programming as an automated powerful formula induction engine. In addition, for computational efficiency and expressive power, we use a compact matrix tree representation equipped with a broad set of functions that can build most currently used similarity functions as well as new ones. Model selection is data driven, because the entire model is symbolically instantiated using only problem training data, and no user-selected functions or parameters are required. We perform thorough comparative experimentations with multiple classification datasets and many existing state-of-the-art embedding methods, which show that the proposed algorithm is very competitive in terms of classification accuracy and generalization ability. PMID:24808595

Rodriguez-Martinez, Eduardo; Tingting Mu; Jianmin Jiang; Goulermas, John Yannis

2013-10-01

369

Lithographic process window optimization for mask aligner proximity lithography  

NASA Astrophysics Data System (ADS)

We introduce a complete methodology for process window optimization in proximity mask aligner lithography. The commercially available lithography simulation software LAB from GenISys GmbH was used for simulation of light propagation and 3D resist development. The methodology was tested for the practical example of lines and spaces, 5 micron half-pitch, printed in a 1 micron thick layer of AZ® 1512HS1 positive photoresist on a silicon wafer. A SUSS MicroTec MA8 mask aligner, equipped with MO Exposure Optics® was used in simulation and experiment. MO Exposure Optics® is the latest generation of illumination systems for mask aligners. MO Exposure Optics® provides telecentric illumination and excellent light uniformity over the full mask field. MO Exposure Optics® allows the lithography engineer to freely shape the angular spectrum of the illumination light (customized illumination), which is a mandatory requirement for process window optimization. Three different illumination settings have been tested for 0 to 100 micron proximity gap. The results obtained prove, that the introduced process window methodology is a major step forward to obtain more robust processes in mask aligner lithography. The most remarkable outcome of the presented study is that a smaller exposure gap does not automatically lead to better print results in proximity lithography - what the "good instinct" of a lithographer would expect. With more than 5'000 mask aligners installed in research and industry worldwide, the proposed process window methodology might have significant impact on yield improvement and cost saving in industry.

Voelkel, Reinhard; Vogler, Uwe; Bramati, Arianna; Erdmann, Andreas; Ünal, Nezih; Hofmann, Ulrich; Hennemeyer, Marc; Zoberbier, Ralph; Nguyen, David; Brugger, Juergen

2014-03-01

370

Hand proximity facilitates spatial discrimination of auditory tones  

PubMed Central

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 “space” 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.

Tseng, Philip; Yu, Jiaxin; Tzeng, Ovid J. L.; Hung, Daisy L.; Juan, Chi-Hung

2014-01-01

371

Clinical application of modified double tracks anastomosis in proximal gastrectomy.  

PubMed

We compared the outcome of two surgical alimentary canal reconstruction methods after proximal gastrectomy. Three hundred ninety-six patients who underwent a radical proximal gastrectomy were randomized into two groups. Group A was treated with modified double tracks anastomosis, and Group B was treated with esophagus-remnant stomach direct anastomosis. Outcome measures were hematological indices, prognostic nutritional index (PNI), plasma hormone concentrations, and Visick index. The operative times in Groups A and B were 210 ± 53 and 150 ± 75 minutes and the hemorrhage volume was 173 ± 67 and 150 ± 75 mL, respectively. Six months after operation, values of hemoglobin concentration, body weights, and PNI indices were significantly increased in Group A compared with Group B. Levels of gastrin and somatostatin were obviously less than preoperative values and levels of cholecystokinin and motilin were significantly higher than preoperative values in both groups. All patients of Group A were classified into Visick index Grades I and II, whereas only 70.37 per cent of Group B belonged to Visick index Grades I and II postoperatively. The overall 3-year survival rate was not significantly different in both groups. Modified double tracks anastomosis as an alimentary canal reconstructive method for radical proximal gastrectomy showed better outcomes than esophagus-remnant stomach direct anastomosis. PMID:22273215

Zhao, Qun; Li, Yong; Guo, Weijia; Zhang, Zhidong; Ma, Zhixue; Jiao, Zhikai

2011-12-01

372

Proximity hybridization-triggered signal switch for homogeneous chemiluminescent bioanalysis.  

PubMed

A proximity hybridization-triggered signal switch was presented for convenient homogeneous chemiluminescent detection of a wide range of affinity target biomolecules, such as oligonucleotides, protein biomarkers, and aptamer-recognized targets. The presence of the target promoted the formation of a proximate complex via the proximity hybridization of two help DNA strands or the DNA strands labeled to affinity ligands, which subsequently unfolded the self-reporting molecular beacon to switch on the chemiluminescence signal. The response could be further amplified with an in situ enzymatic recycling strategy for highly sensitive chemiluminescence detection. By using an antibody as the affinity ligand, this simple protocol could sensitively detect protein biomarker in a concentration range of 6 orders of magnitude with a detection limit down to 80 fM. With the use of an aptamer as the affinity ligand, a method for homogeneous chemiluminescent detection of thrombin was proposed. The one-step and wash-free assay showed good selectivity and required only 1 ?L of sample. Its high sensitivity, acceptable accuracy, and satisfactory versatility of analytes led to various applications in bioanalysis. PMID:24832725

Zong, Chen; Wu, Jie; Liu, Mengmeng; Yang, Linlin; Liu, Lin; Yan, Feng; Ju, Huangxian

2014-06-01

373

Glutamatergic signaling maintains the epithelial phenotype of proximal tubular cells.  

PubMed

Epithelial-mesenchymal transition (EMT) contributes to the progression of renal tubulointerstitial fibrosis. The N-methyl-d-aspartate receptor (NMDAR), which is present in proximal tubular epithelium, is a glutamate receptor that acts as a calcium channel. Activation of NMDAR induces actin rearrangement in cells of the central nervous system, but whether it helps maintain the epithelial phenotype of the proximal tubule is unknown. Here, knockdown of NMDAR1 in a proximal tubule cell line (HK-2) induced changes in cell morphology, reduced E-cadherin expression, and increased ?-SMA expression. Induction of EMT with TGF-?1 led to downregulation of both E-cadherin and membrane-associated ?-catenin, reorganization of F-actin, expression of mesenchymal markers de novo, upregulation of Snail1, and increased cell migration; co-treatment with NMDA attenuated all of these changes. Furthermore, NMDA reduced TGF-?1-induced phosphorylation of Erk1/2 and Akt and the activation of Ras, suggesting that NMDA antagonizes TGF-?1-induced EMT by inhibiting the Ras-MEK pathway. In the unilateral ureteral obstruction model, treatment with NMDA blunted obstruction-induced upregulation of ?-SMA, FSP1, and collagen I and downregulation of E-cadherin. Taken together, these results suggest that NMDAR plays a critical role in preserving the normal epithelial phenotype and modulating tubular EMT. PMID:21597037

Bozic, Milica; de Rooij, Johan; Parisi, Eva; Ortega, Marta Ruiz; Fernandez, Elvira; Valdivielso, José M

2011-06-01

374

Glutamatergic Signaling Maintains the Epithelial Phenotype of Proximal Tubular Cells  

PubMed Central

Epithelial–mesenchymal transition (EMT) contributes to the progression of renal tubulointerstitial fibrosis. The N-methyl-d-aspartate receptor (NMDAR), which is present in proximal tubular epithelium, is a glutamate receptor that acts as a calcium channel. Activation of NMDAR induces actin rearrangement in cells of the central nervous system, but whether it helps maintain the epithelial phenotype of the proximal tubule is unknown. Here, knockdown of NMDAR1 in a proximal tubule cell line (HK-2) induced changes in cell morphology, reduced E-cadherin expression, and increased ?-SMA expression. Induction of EMT with TGF-?1 led to downregulation of both E-cadherin and membrane-associated ?-catenin, reorganization of F-actin, expression of mesenchymal markers de novo, upregulation of Snail1, and increased cell migration; co-treatment with NMDA attenuated all of these changes. Furthermore, NMDA reduced TGF-?1–induced phosphorylation of Erk1/2 and Akt and the activation of Ras, suggesting that NMDA antagonizes TGF-?1–induced EMT by inhibiting the Ras-MEK pathway. In the unilateral ureteral obstruction model, treatment with NMDA blunted obstruction-induced upregulation of ?-SMA, FSP1, and collagen I and downregulation of E-cadherin. Taken together, these results suggest that NMDAR plays a critical role in preserving the normal epithelial phenotype and modulating tubular EMT.

Bozic, Milica; de Rooij, Johan; Parisi, Eva; Ortega, Marta Ruiz; Fernandez, Elvira

2011-01-01

375

Proximal attrition facets: morphometric, demographic, and aging characteristics.  

PubMed

Although interproximal attrition is considered to be limited in modern populations, it has important clinical implications. However, in contrast to occlusal attrition, proximal attrition receives limited scientific attention. The main purpose of the current study was to fill this void. Seven-hundred and sixty-five teeth were collected from 255 skulls of subjects 18-75 yr of age. For each individual, three mandibular teeth (the first and second premolars and the first molar) were examined for proximal attrition facets (PAFs). The results provide detailed information on the size, shape, and location of the facets according to age cohort, gender, and ethnicity. The validity of the method used to measure the facets was also examined. The major findings were as follows: PAFs are usually located on the upper half of the crown proximal aspect; in each tooth, the mesial facet is more lingually positioned and the distal facet is more buccally positioned; the majority of the facets are subrectangular in shape; the size of the facets tends to increase in an anteroposterior direction (from premolars to molars); and facet size and location are age- and sex-dependent and ethnicity-independent. It is our recommendation that dentists bear in mind that interproximal attrition is a dynamic, long-term process and needs to be considered in many clinical scenarios. PMID:24930490

Sarig, Rachel; Hershkovitz, Israel; Shvalb, Nir; Sella-Tunis, Tatiana; May, Hila; Vardimon, Alexander D

2014-08-01

376

Feasibility Determination of Proximity Transducers Using the Hall Effect and Varying Inductance Principles.  

National Technical Information Service (NTIS)

The Hall effect and varying inductance principles can be applied successfully to proximity type transducer switches required in advanced aircraft electric systems. These contactless proximity switches are applicable to the Navy's SOSTEL and multiplexing s...

J. P. Triolo

1969-01-01

377

Expression cloning of human and rat renal cortex Na/Pi cotransport.  

PubMed Central

We have isolated two cDNA clones, NaPi-2 and NaPi-3, by screening rat kidney cortex and human kidney cortex cDNA libraries, respectively, for expression of sodium-dependent phosphate transport in Xenopus laevis oocytes. Substrate specificity and a detailed kinetic analysis (Na, Pi, H+ concentrations) suggested that expressed uptake activities relate to proximal tubular brush border membrane Na/Pi cotransport. NaPi-2 cDNA contains 2464 bp encoding a protein of 637 aa; NaPi-3 cDNA contains 2573 bp encoding a protein of 639 aa. NaPi-2- and NaPi-3-deduced protein sequences show high homology to each other but are different from the protein sequence deduced from the previously cloned NaPi-1 cDNA (from rabbit proximal tubules). Hydropathy profile predictions suggest at least eight membrane-spanning regions in NaPi-2/3-related proteins. In vitro translation results in proteins of the expected size and suggests glycosylation. Northern blot analysis shows corresponding mRNA species (approximately 2.7 kb) in kidney cortex of various species but no hybridization with RNAs isolated from a variety of other tissues (including intestinal segments); a hybridization signal (approximately 4.8 kb) was observed only in the lung (human). We conclude that we have structurally identified two closely related proteins most likely involved in human and rat renal brush border Na/Pi cotransport. Images Fig. 4 Fig. 5

Magagnin, S; Werner, A; Markovich, D; Sorribas, V; Stange, G; Biber, J; Murer, H

1993-01-01

378

Shifting Proximities: The Maritime Ports Sector in an Era of Global Supply Chains  

Microsoft Academic Search

Hall P. V. and Jacobs W. Shifting proximities: the maritime ports sector in an era of global supply chains, Regional Studies. Economic geographers argue that spatial and non-spatial dimensions of proximity are central to innovation and collective action. The various dimensions of proximity in relation to maritime ports are examined. Global supply chains represent a shift in organizational and cognitive

Peter V. Hall; Wouter Jacobs

2010-01-01

379

STM study of the superconducting proximity effect at 60 mK: influence of interface transparency  

Microsoft Academic Search

Proximity effect of a superconductor on a normal metal has a renewed interest recently. The effort, so far, has been to make the N-S interface as transparent and clean as possible to enhance the proximity effects. Here, we investigate the influence of interface transparency on the superconducting proximity effect of niobium on gold by probing the local density of states

H. Courtois; A. K. Gupta; L. Cretinon; N. Moussy; B. Pannetier

2002-01-01

380

Dissociation of gluconeogenesis from fluid and phosphate reabsorption in isolated rabbit proximal tubules  

Microsoft Academic Search

Dissociation of gluconeogenesis from fluid and phosphate reabsorption in isolated rabbit proximal tubules. Gluconeogenesis in the kidney is a metabolic function characteristic of proximal tubules. Recent studies suggest that renal gluconeogenesis (GNG) may in some way be coupled to fluid and phosphate reabsorption in the proximal tubule. Therefore, the present studies examined more directly the relationship between GNG and transport

Norimoto Yanagawa; Glenn T Nagami; Ok Jo; Jiro Uemasu; Kiyoshi Kurokawa

1984-01-01

381

Delayed presentation: dislocation of the proximal tibiofibular joint after knee dislocation.  

PubMed

Attention is brought to a unique case of an anterior dislocation of the proximal tibiofibular joint detected 1 month following closed reduction of a posterior knee dislocation. Open reduction and internal fixation were necessary to achieve a stable proximal tibiofibular joint. Additional attention should be paid to the proximal tibiofibular joint when evaluating acute or chronic knee dislocation. PMID:7965299

Fallon, P; Virani, N S; Bell, D; Hollinshead, R

1994-08-01

382

IL1? stimulated TNF? production by cultured human proximal tubular epithelial cells  

Microsoft Academic Search

IL-1? stimulated TNF? production by cultured human proximal tubular epithelial cells. Tumor necrosis factor alpha (TNF?) production by proximal tubuli was studied by immunoperoxidase staining of 20 renal biopsies from transplant patients. A positive staining for TNF? on proximal tubuli was seen in nine out of 15 patients with interstitial infiltrate, five without clinical significant rejection and four with moderate

Benito A Yard; Mohamed R Daha; Mariska Kooymans-Couthino; Jan A Bruijn; Marion E Paape; E Schrama; Leendert A van Es; Fokko J van der Woude

1992-01-01

383

In Vivo Study of Transepithelial Potential Difference (TEPD) in Proximal Convoluted Tubules of Rat Kidney by Synchronization Modulation Electric Field.  

PubMed

Synchronization modulation (SM) electric field has been shown to effectively activate function of Na(+)/K(+) pumps in various cells and tissues, including skeletal muscle cells, cardiomyocyte, monolayer of cultured cell line, and peripheral blood vessels. We are now reporting the in vivo studies in application of the SM electric field to kidney of living rats. The field-induced changes in the transepithelial potential difference (TEPD) or the lumen potential from the proximal convoluted tubules were monitored. The results showed that a short time (20 s) application of the SM electric field can significantly increase the magnitude of TEPD from 1-2 mV to about 20 mV. The TEPD is an active potential representing the transport current of the Na/K pumps in epithelial wall of renal tubules. This study showed that SM electric field can increase TEPD by activation of the pump molecules. Considering renal tubules, many active transporters are driven by the Na(+) concentration gradient built by the Na(+)/K(+) pumps, activation of the pump functions and increase in the magnitude of TEPD imply that the SM electric field may improve reabsorption functions of the renal tubules. PMID:24894719

Clausell, Mathis; Fang, Zhihui; Chen, Wei

2014-07-01

384

Spectrum and subcellular determinants of fluorinated anesthetic-mediated proximal tubular injury.  

PubMed Central

Currently used fluorinated anesthetics are chemically related to methoxyflurane (MF), a drug that caused many cases of clinical acute renal failure during previous widespread use. To determine whether newer fluorinated anesthetics might also have nephrotoxic effects, three currently used agents (isoflurane (IF), sevoflurane (SF), and desflurane) or MF were added to rat proximal tubular segments, followed by assessments of cell integrity (ATP levels and percent lactic dehydrogenase release). Ether served as a negative control. MF, IF, and SF each induced lethal proximal tubular segment injury (up to 92, 71, and 30% lactic dehydrogenase release, respectively) and massive ATP depletion. ATP losses were observed at or near clinically relevant drug levels, they preceded lethal injury, and they correlated with approximately 50% and approximately 100% reductions in total and Na,K-ATPase-driven respiration, respectively. Clinically relevant inorganic fluoride levels simulated fluorinated anesthetic toxicity. However, fluoride release from the anesthetics (a cytochrome P450 process) did not appear to be required for toxicity (no protection with P450 inhibitors and no detectable inorganic fluoride release). As IF was judged to be one-third as toxic as MF, subclinical tubular injury (increased urine N-acetyl-beta-D-glucosaminidase (NAG) levels) after its use was sought in 19 surgical patients. Fifteen patients undergoing comparable operations with SF (approximately one-half as toxic as IF in vitro) and nine patients undergoing regional/ local anesthesia were controls. The IF group doubled its urinary NAG levels by the end of surgery (P < 0.005). Conversely, NAG levels remained stable in both control groups. The conclusions are that 1) currently used fluorinated anesthetics, particularly IF, share (but to a lesser degree) MFs tubulotoxic effects, 2) ATP depletion (probably due to decreased production) and Na,K-ATPase inhibition are likely contributing mechanisms, 3) fluoride is a prime determinant of this toxicity, and 4) tubular injury can be expressed at or near clinically relevant anesthetic/inorganic fluoride levels. That increased enzymuria can develop in patients after IF anesthesia suggests that the above in vitro data could have potential clinical relevance in selected patients.

Lochhead, K. M.; Kharasch, E. D.; Zager, R. A.

1997-01-01

385

Topology of the type IIa Na+/P(i) cotransporter.  

PubMed

The type IIa Na(+)/P(i) cotransporter (NaPi-IIa) plays a key role in the reabsorption of inorganic phosphate (P(i)) in the renal proximal tubule. The rat NaPi-IIa isoform is a protein of 637 residues for which different algorithms predict 8-12 transmembrane domains (TMDs). Epitope tagging experiments demonstrated that both the N and the C termini of NaPi-IIa are located intracellularly. Site-directed mutagenesis revealed two N-glycosylation sites in a large putative extracellular loop. Results from structure-function studies suggested the assembly of two similar opposed regions that possibly constitute part of the substrate translocation pathway for one phosphate ion together with three sodium ions. Apart from these topological aspects, other structural features of NaPi-IIa are not known. In this study, we have addressed the topology of NaPi-IIa using in vitro transcription/translation of HK-M0 and HK-M1 fusion vectors designed to test membrane insertion properties of cDNA sequences encoding putative NaPi-IIa TMDs. Based on the results of in vitro transcription/translation analyses, we propose a model of NaPi-IIa comprising 12 TMDs, with both N and C termini orientated intracellularly and a large hydrophilic extracellular loop between the fifth and sixth TMDs. The proposed model is in good agreement with the prediction of the NaPi-IIa structure obtained by the hidden Markov algorithm HMMTOP. PMID:17206517

Radanovic, Tamara; Gisler, Serge M; Biber, Jürg; Murer, Heini

2006-01-01

386

Functional results after proximal row carpectomy to salvage a wrist.  

PubMed

Proximal row carpectomy is a movement-preserving procedure in the treatment of arthrosis of the wrist. We have retrospectively assessed the objective and subjective functional results after proximal row carpectomy. Assessment of outcome included measurement of range of movement (ROM), grip strength and self-assessment of pain relief with a visual analogue scale (VAS) and the Disabilities of arm, shoulder, and hand (DASH) questionnaire. Results were graded using the Mayo and Krimmer wrist scores. Fourty-five patients (mean age 48 (30-67) years) were evaluated with a follow-up of 32 (8-115) months. Underlying conditions included: degenerative arthritis secondary to scapholunate advanced collapse deformity, or chronic scaphoid non-union (n=35), Kienbock disease stage III (n=4), chronic perilunate dislocation and fracture-dislocation (n=4), avascular necrosis of the scaphoid (n=1), and severe radiocarpal arthrosis secondary to distal radial fracture (n=1). Active ROM for wrist extension and flexion was 70 degrees and mean radial and ulnar deviation 30.8 degrees . Grip strength was 51% of the unaffected side. The average DASH score was 26. The intensity of the pain, measured by VAS, was reduced by 44% after strenuous activities and by 71% at rest. The Mayo and Krimmer wrist scores were 55 and 62 points indicating good results; 32 patients returned to work and 25 patients to their former occupation. Our results show that proximal row carpectomy is a technically easy operation that preserves a satisfying ROM and pain relief, and is recommended when the head of the capitate and the lunate fossa are not affected by arthrosis. PMID:18991174

Kremer, Thomas; Sauerbier, Michael; Trankle, Markus; Dragu, Adrian; Germann, Guenter; Baumeister, Steffen

2008-01-01

387

Proximal humerus reconstruction after tumour resection: biological versus endoprosthetic reconstruction.  

PubMed

The purpose of this study was to compare the outcome, complications and survival of the three most commonly used surgical reconstructions of the proximal humerus after transarticular tumour resection. Between 1985 and 2005, 38 consecutive proximal humeral reconstructions using allograft-prosthesis composite (n = 10), osteoarticular allograft (n = 13) or a modular tumour prosthesis (n = 14) were performed in our clinic. The mean follow-up was ten years (1-25). Of these, 27 were disease free at latest follow-up (mean 16.8 years) and ten had died of disease. The endoprosthetic group presented the smallest complication rate of 21% (n =1), compared to 40% (n = 4) in the allograft-prosthesis composite and 62% (n = 8) in the osteoarticular allograft group. Only one revision was performed in the endoprosthetic group, in a case of shoulder instability. Infection after revision (n = 3), pseudoarthrosis (n = 2), fracture of the allograft (n = 3) and shoulder instability (n = 4) were the major complications of allograft use in general. Kaplan-Meier analysis showed a significantly better implant survival for the endoprosthetic group (log-rank p = 0.002). At final follow-up the Musculoskeletal Tumour Society scores were an average of 72% for the allograft-prosthetic composite (n = 7, median follow-up 17 years), 76% for the osteoarticular allograft (n = 3, 19 years) and 77% for the endoprosthetic reconstruction (n = 10, 5 years) groups. An endoprosthetic reconstruction after transarticular proximal humeral resection resulted in the lowest complication rate, highest implant survival and comparable functional results when compared to allograft-prosthesis composite and osteoarticular allograft use. We believe that the surgical approach that best preserves the abductor mechanism and provides sufficient surgical exposure for tumour resection contributed to better functional results and glenohumeral stability in the endoprosthetic group. PMID:21085956

van de Sande, Michiel A J; Dijkstra, P D Sander; Taminiau, Antonie H M

2011-09-01

388

Uncemented allograft-prosthetic composite reconstruction of the proximal femur  

PubMed Central

Background: Allograft–prosthetic composite can be divided into three groups names cemented, uncemented, and partially cemented. Previous studies have mainly reported outcomes in cemented and partially cemented allograft–prosthetic composites, but have rarely focused on the uncemented allograft–prosthetic composites. The objectives of our study were to describe a surgical technique for using proximal femoral uncemented allograft–prosthetic composite and to present the radiographic and clinical results. Materials and Methods: Twelve patients who underwent uncemented allograft–prosthetic composite reconstruction of the proximal femur after bone tumor resection were retrospectively evaluated at an average followup of 24.0 months. Clinical records and radiographs were evaluated. Results: In our series, union occurred in all the patients (100%; range 5-9 months). Until the most recent followup, there were no cases with infection, nonunion of the greater trochanter, junctional bone resorption, dislocation, allergic reaction, wear of acetabulum socket, recurrence, and metastasis. But there were three periprosthetic fractures which were fixed using cerclage wire during surgery. Five cases had bone resorption in and around the greater trochanter. The average Musculoskeletal Tumor Society (MSTS) score and Harris hip score (HHS) were 26.2 points (range 24-29 points) and 80.6 points (range 66.2-92.7 points), respectively. Conclusions: These results showed that uncemented allograft–prosthetic composite could promote bone union through compression at the host–allograft junction and is a good choice for proximal femoral resection. Although this technology has its own merits, long term outcomes are yet not validated.

Min, Li; Peng, Jing; Duan, Hong; Zhang, Wenli; Zhou, Yong; Tu, Chongqi

2014-01-01

389

The proximate unit in Chinese handwritten character production  

PubMed Central

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.

Chen, Jenn-Yeu; Cherng, Rong-Ju

2013-01-01

390

Saccharomyces boulardii upgrades cellular adaptation after proximal enterectomy in rats  

PubMed Central

BACKGROUND—Saccharomyces boulardii is a non-pathogenic yeast which exerts trophic effects on human and rat small intestinal mucosa.?AIMS—To examine the effects of S boulardii on ileal adaptation after proximal enterectomy in rats.?METHODS—Wistar rats, aged eight weeks, underwent 60% proximal resection or transection and received by orogastric intubation either 1 mg/g body wt per day lyophilised S boulardii or the vehicle for seven days. The effects on ileal mucosal adaptation were assessed eight days after surgery.?RESULTS—Compared with transection, resection resulted in mucosal hyperplasia with significant decreases in the specific and total activities of sucrase, lactase, and maltase. Treatment of resected animals with S boulardii had no effect on mucosal hyperplasia but did upgrade disaccharidase activities to the levels of the transected group. Enzyme stimulation by S boulardii was associated with significant increases in diamine oxidase activity and mucosal polyamine concentrations. Likewise, sodium dependent D-glucose uptake by brush border membrane vesicles, measured as a function of time and glucose concentration in the incubation medium, was significantly (p<0.05) increased by 81% and three times respectively in the resected group treated with S boulardii. In agreement with this, expression of the sodium/glucose cotransporter-1 in brush border membranes of resected rats treated with S boulardii was enhanced twofold compared with resected controls.?CONCLUSION—Oral administration of S boulardii soon after proximal enterectomy improves functional adaptation of the remnant ileum.???Keywords: Saccharomyces boulardii; intestine; adaptation; polyamines; brush border membrane enzymes; glucose uptake

Buts, J; De Keyser, N; Marandi, S; Hermans, D; Sokal, E; Chae, Y; Lambotte, L; Chanteux, H; Tulkens, P

1999-01-01

391

Cysteine mutagenesis reveals alternate proximity between transmembrane domain 2 and hairpin loop 1 of the glutamate transporter EAAT1.  

PubMed

Excitatory amino acid transporter 1 (EAAT1) plays an important role in restricting the neurotoxicity of glutamate. Previous structure-function studies have provided evidence that reentrant helical hairpin loop (HP) 1 has predominant function during the transport cycle. The proposed internal gate HP1 is packed against transmembrane domain (TM) 2 and TM5 in its closed state, and two residues located in TM2 and HP2 of EAAT1 are in close proximity. However, the spatial relationship between TM2 and HP1 during the transport cycle remains unknown. In this study, we used chemical cross-linking of introduced cysteine pair (V96C and S366C) in a cysteine-less version of EAAT1 to assess the proximity of TM2 and HP1. Here, we show that inhibition of transport by copper(II)(1,10-phenanthroline)3 (CuPh) and cadmium ion (Cd(2+)) were observed in the V96C/S366C mutant. Glutamate or potassium significantly protected against the inhibition of transport activity of V96C/S366C by CuPh, while TBOA potentiated the inhibition of transport activity of V96C/S366C by CuPh. We also checked the kinetic parameters of V96C/S366C treated with or without CuPh in the presence of NaCl, NaCl + L-glutamate, NaCl + TBOA, and KCl, respectively. The sensitivity of V96C and S366C to membrane-impermeable sulfhydryl reagent MTSET [(2-trimethylammonium) methanethiosulfonate] was attenuated by glutamate or potassium. TBOA had no effect on the sensitivity of V96C and S366C to MTSET. These data suggest that the spatial relationship between Val-96 of TM2 and Ser-366 of HP1 is altered in the transport cycle. PMID:24692063

Zhang, Yunlong; Zhang, Xiuping; Qu, Shaogang

2014-07-01

392

FXYD Proteins Stabilize Na,K-ATPase  

PubMed Central

FXYD proteins are a family of seven small regulatory proteins, expressed in a tissue-specific manner, that associate with Na,K-ATPase as subsidiary subunits and modulate kinetic properties. This study describes an additional property of FXYD proteins as stabilizers of Na,K-ATPase. FXYD1 (phospholemman), FXYD2 (? subunit), and FXYD4 (CHIF) have been expressed in Escherichia coli and purified. These FXYD proteins associate spontaneously in vitro with detergent-soluble purified recombinant human Na,K-ATPase (?1?1) to form ?1?1FXYD complexes. Compared with the control (?1?1), all three FXYD proteins strongly protect Na,K-ATPase activity against inactivation by heating or excess detergent (C12E8), with effectiveness FXYD1 > FXYD2 ? FXYD4. Heating also inactivates E1 ? E2 conformational changes and cation occlusion, and FXYD1 protects strongly. Incubation of ?1?1 or ?1?1FXYD complexes with guanidinium chloride (up to 6 m) causes protein unfolding, detected by changes in protein fluorescence, but FXYD proteins do not protect. Thus, general protein denaturation is not the cause of thermally mediated or detergent-mediated inactivation. By contrast, the experiments show that displacement of specifically bound phosphatidylserine is the primary cause of thermally mediated or detergent-mediated inactivation, and FXYD proteins stabilize phosphatidylserine-Na,K-ATPase interactions. Phosphatidylserine probably binds near trans-membrane segments M9 of the ? subunit and the FXYD protein, which are in proximity. FXYD1, FXYD2, and FXYD4 co-expressed in HeLa cells with rat ?1 protect strongly against thermal inactivation. Stabilization of Na,K-ATPase by three FXYD proteins in a mammalian cell membrane, as well the purified recombinant Na,K-ATPase, suggests that stabilization is a general property of FXYD proteins, consistent with a significant biological function.

Mishra, Neeraj Kumar; Peleg, Yoav; Cirri, Erica; Belogus, Talya; Lifshitz, Yael; Voelker, Dennis R.; Apell, Hans-Juergen; Garty, Haim; Karlish, Steven J. D.

2011-01-01

393

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.

2003-01-01

394

[Fracture of a pyrolytic carbon proximal interphalangeal prosthesis: clinical case].  

PubMed

Pyrolytic carbon prostheses are one of the options for the treatment of arthritis of the proximal interphalangeal (PIP) joint. Deficiency of the extensor mechanism, instability, dislocation and infection are the most frequent causes described for revision. We report the case of a female patient who underwent a PIP arthroplasty with a pyrolytic carbon implant of her right long finger; she suffered from an implant fracture only 11 months after surgery, a rare complication of this kind of implant; it makes think to fragility of this kind of implant. PMID:24418023

Paulos, R-G; Sousa E Silva, R; Le Viet, D

2014-02-01

395

Proximal Humeral Fractures: A Review of Current Concepts  

PubMed Central

The majority of proximal humerus fractures are sustained via low energy falls in the elderly population. These patients can attain an acceptable level of function via non-operative treatment. There is yet to be a clear consensus on treatment options suitable for those that fall outside of this majority group. Open reduction internal fixation, intra medullary nailing and arthroplasty surgery have all been used to varying effects. Good results are achievable if complications such as mal-union, non-union and avascular necrosis can be avoided. This review aims to clarify the options available to the current day trauma surgeon.

Widnall, James C.; Dheerendra, Sujay K.; Malal, Joby Jacob George; Waseem, Mohammed

2013-01-01

396

Groups as units of functional analysis, individuals as proximate mechanisms.  

PubMed

Whenever selection operates at a given level of a multitier hierarchy, units at that level should become the object of functional analysis, and units at lower levels should be studied as proximate mechanisms. This intuition already exists for the study of genes in individuals, when individuals are the unit of selection. It is only beginning to be applied for the study of individuals in groups, when groups are the unit of selection. Smaldino's target article is an important step in this direction with an emphasis on human cultural evolution, but the same algorithm applies to all multilevel evolutionary processes. PMID:24970426

Wilson, David Sloan

2014-06-01

397

Osteochondroma Arising from the Proximal Fibula: A Rare Presentation  

PubMed Central

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.

Malgonde, Monika; Jain, Pramod

2014-01-01

398

Surgical Management of 121 Benign Proximal Fibula Tumors  

Microsoft Academic Search

Background  Tumors of the fibula comprise only 2.5% of primary bone lesions. Patients with aggressive benign tumors in the proximal fibula\\u000a may require en bloc resection. Peroneal nerve function, knee stability, and recurrence are substantial concerns with these\\u000a resections. The incidence and fate of these complications is not well-known owing to the small numbers of patients in previous\\u000a reports.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We therefore

Matthew P. Abdel; Panayiotis J. Papagelopoulos; Mark E. Morrey; Doris E. Wenger; Peter S. Rose; Franklin H. Sim

2010-01-01

399

Distributed proximity sensor system having embedded light emitters and detectors  

NASA Technical Reports Server (NTRS)

A distributed proximity sensor system is provided with multiple photosensitive devices and light emitters embedded on the surface of a robot hand or other moving member in a geometric pattern. By distributing sensors and emitters capable of detecting distances and angles to points on the surface of an object from known points in the geometric pattern, 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)

1990-01-01

400

Autophagy protects proximal tubular cells from injury and apoptosis  

PubMed Central

Autophagy is upregulated during ischemia–reperfusion (IR)-induced and cisplatin-induced acute kidney injury (AKI). Proximal tubule-specific Atg7 knockout mice exhibited increased renal injury compared with wild-type mice following cisplatin- and IR-induced AKI. Inhibition of autophagy by chloroquine aggravated AKI, whereas upregulation of autophagy by rapamycin recovered lost renal function and histology, further indicating a protective role of autophagy in AKI. These findings reported by Jiang et al. will provide stimulus to further examine the role and mechanism of the enhancement of autophagy in AKI.

Kaushal, Gur P.

2014-01-01

401

Outcome of closed proximal phalangeal fractures of the hand  

PubMed Central

Background: The proximal phalanx (PP) of the fingers is fractured more frequently than the middle or even distal phalanges. The problems of malunion, stiffness and sometimes loss of skin or other soft tissues associated with PP fracture increases the disability. The optimum treatment depends on fracture location, fracture geometry and fracture stability. The objective of the study was to analyse the treatment outcome in a series of closed proximal phalangeal fractures of the hand. Materials and Methods: Eighty-four proximal phalangeal fractures in 68 patients were enrolled from 2007 to 2009. The treatment modalities were broadly categorised into two groups, Group A consisted of conservative treatment, and Group B consisted of surgical treatment. Group A included 47 digits treated with closed reduction (CR) with immobilization (n=43), extension block cast and dynamic traction (n=4), while 37 digits were treated in Group B, which included closed or open reduction (OR) and internal fixation (IF) with K-wires (n=31), OR and IF with stainless-steel wiring (n=2), and mini external-fixator (n=4). Belsky's criteria and Gingrass’ criteria were used for assessment of finger injuries and to assess the efficacy of conservative and surgical modalities for closed proximal phalangeal fractures of the hand. Results: Average period of follow-up was 1 year (range 10-14 months). The excellent to good results seen in Groups A and B were 89% and 92%, respectively. Six complications were seen in Group A, which included four cases with malunion and two cases with digital stiffness. Three complications were seen in Group B, which included one each of malunion, digital stiffness and extensor lag. Overall, maximum poor results (n=4) were seen with CR and buddy strapping. Conclusion: Conservative treatment is an inexpensive method, particularly suitable for stable fractures, and in patients who are poor candidates for surgery, Surgical modalities have distinct advantage of stable fixation, but with added risk of digital stiffness. Percutaneous pinning is a reliable, most commonly used surgical modality and technically easier. Both conservative and surgical modalities have good efficacy when used judiciously

Singh, Jaswinder; Jain, Karun; Mruthyunjaya; Ravishankar, R

2011-01-01

402

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

2007-10-10

403

Nanosized Electronic Cooler Combined with Superconducting Proximity Effect Thermometry  

NASA Astrophysics Data System (ADS)

Electronic coolers have the potential to lower the temperature of mesoscopic electronic systems well below the lattice temperature with the final goal to reach ultimately an electronic temperature in the 10 mK range. A challenging task is to design a reliable electronic thermometry for this temperature range, including extremely low power dissipation, good sensitivity and preferably a theoretical description of the response with few experimentally determined parameters. We present an experimental realization and characterization of a nano sized electronic cooler with a superconducting proximity effect thermometer. We demonstrate an improved operation mode of the thermometer using escape statistics from the superconducting to the normal state.

Meschke, Matthias

2014-06-01

404

Nanosized Electronic Cooler Combined with Superconducting Proximity Effect Thermometry  

NASA Astrophysics Data System (ADS)

Electronic coolers have the potential to lower the temperature of mesoscopic electronic systems well below the lattice temperature with the final goal to reach ultimately an electronic temperature in the 10 mK range. A challenging task is to design a reliable electronic thermometry for this temperature range, including extremely low power dissipation, good sensitivity and preferably a theoretical description of the response with few experimentally determined parameters. We present an experimental realization and characterization of a nano sized electronic cooler with a superconducting proximity effect thermometer. We demonstrate an improved operation mode of the thermometer using escape statistics from the superconducting to the normal state.

Meschke, Matthias

2014-04-01

405

Proximity effect thermometer for local temperature measurements on mesoscopic samples.  

SciTech Connect

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

1999-11-29

406

Evaluation of benzalkonium chloride chemoneurolytic proximal gastric vagotomy  

Microsoft Academic Search

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

1998-01-01

407

Residential Proximity to Environmental Hazards and Adverse Health Outcomes  

PubMed Central

How living near environmental hazards contributes to poorer health and disproportionate health outcomes is an ongoing concern. We conducted a substantive review and critique of the literature regarding residential proximity to environmental hazards and adverse pregnancy outcomes, childhood cancer, cardiovascular and respiratory illnesses, end-stage renal disease, and diabetes. Several studies have found that living near hazardous wastes sites, industrial sites, cropland with pesticide applications, highly trafficked roads, nuclear power plants, and gas stations or repair shops is related to an increased risk of adverse health outcomes. Government agencies should consider these findings in establishing rules and permitting and enforcement procedures to reduce pollution from environmentally burdensome facilities and land uses.

Maantay, Juliana A.; Chakraborty, Jayajit

2011-01-01

408

Prognostic factors for the elderly with proximal femoral fracture.  

PubMed Central

A prospective study of 125 elderly patients (over 65 years) with proximal femoral fracture was carried out to compare pre-fracture sociomedical factors with the local and general complications following surgical treatment, in predicting mortality and length of stay. A poor pre-fracture mental state was more important than associated physical illness in predicting mortality. Pre-fracture mobility state was the most useful early prognostic predictor of length of hospitalization. Post-operative general complications were the most significant in predicting mortality and length of hospitalization, and more important than failure of operative technique.

Young, T B; Gibbs, A C

1984-01-01

409

Ground plane insulating coating for proximity focused devices  

DOEpatents

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.

1998-07-14

410

Ground plane insulating coating for proximity focused devices  

DOEpatents

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)

1998-01-01

411

A high T c proximity effect superconductor and its superconductivity  

NASA Astrophysics Data System (ADS)

Using detail dc magnetization measurement method, a high T c proximity effect superconductor has been discovered in single phase Y 1Ba 2Cu 3O 7-? bulk superconductor. Its superconductivities have been studied. Superconducting parameters was deduced and footnoted by a. These parameters are T ca = 84.7 K, H cla( O) = 15.6 Oe, H ca( O) = 108.1 Oe, H c2a( O) = 372.2 Oe, ? ( O) = 2.3 x10 -5cm, ?( O) = 9.4 x10 -6cm, ?= 2.44, ?= 2.6 x10 -8J cm -3K-2, 2 ? ?/K BT c = 3.56.

Xiaowen, Cao; Tingyu, Zhang; Guchang, Han

1988-12-01

412

A computed tomography-based analysis of proximal femoral geometry for lateral impingement with two types of proximal femoral nail anterotation in subtrochanteric fractures  

Microsoft Academic Search

ObjectiveTo evaluate and analyse the geometrical discrepancies between the proximal femur and two types of AO\\/Association for the Study of Internal Fixation (AO\\/ASIF) Proximal Femoral Nail Anterotation (PFNA\\/PFNA-II) using computed tomography (CT)-based analysis in Asian patients, and its implication in lateral cortical impingement during reduction intra-operatively in subtrochanteric fractures.

Vineet Tyagi; Jae Hyuk Yang; Kwang Jun Oh

2010-01-01

413

Proximal myotonic dystrophy—a family with autosomal dominant muscular dystrophy, cataracts, hearing loss and hypogonadism: heterogeneity of proximal myotonic syndromes?  

Microsoft Academic Search

We describe a family with an autosomal dominant, multisystem disorder, consisting of late-onset proximal muscular dystrophy, electrophysiological myotonia, cataracts, late-onset deafness and male hypogonadism. Four patients were available for clinical examinations. Examination of asymptomatic family members revealed another patient with bilateral cataracts but without definite muscle disorder. Five deceased members of the family had proximal muscle weakness, reportedly or confirmed

Bjarne Udd; Ralf Krahe; Carina Wallgren-Pettersson; Björn Falck; Hannu Kalimo

1997-01-01

414

Cancer risk and residential proximity to cranberry cultivation in Massachusetts.  

PubMed Central

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.

Aschengrau, A; Ozonoff, D; Coogan, P; Vezina, R; Heeren, T; Zhang, Y

1996-01-01

415

Proximity effect in superconductor/conical magnet/ferromagnet heterostructures  

NASA Astrophysics Data System (ADS)

At the interface between a superconductor and a ferromagnetic metal spin-singlet Cooper pairs can penetrate into the ferromagnetic part of the heterostructure with an oscillating and decaying spin-singlet Cooper pair density. However, if the interface allows for a spin-mixing effect, equal-spin spin-triplet Cooper pairs can be generated that can penetrate much further into the ferromagnetic part of the heterostructure, known as the long-range proximity effect. Here, we present results of spin-mixing based on self-consistent solutions of the microscopic Bogoliubov-de Gennes equations in the clean limit incorporating a tight-binding model. In particular, we include a conical magnet into our model heterostructure to generate the spin-triplet Cooper pairs and analyse the influence of conical and ferromagnetic layer thickness on the unequal-spin and equal-spin spin-triplet pairing correlations. It will be shown that, in agreement with experimental observations, a minimum thickness of the conical magnet is necessary to generate a sufficient amount of equal-spin spin-triplet Cooper pairs allowing for the long-range proximity effect.

Fritsch, Daniel; Annett, James F.

2014-05-01

416

Proximity to Pollution Sources and Risk of Amphibian Limb Malformation  

PubMed Central

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.

Taylor, Brynn; Skelly, David; Demarchis, Livia K.; Slade, Martin D.; Galusha, Deron; Rabinowitz, Peter M.

2005-01-01

417

Shoulder function after prosthetic replacement of proximal humerus.  

PubMed

Between 1973 and 1985 eighteen patients with bone tumours and two patients with comminuted fractures had their proximal humerus replaced with a custom made isoelastic hemiendoprosthesis. In 1987 a clinical and radiographical review was performed of eleven patients with a mean follow up time of seven years, range 3-10 years. Four patients had pain at rest and six patients experienced severe pain on exertion. Active range of motion was poor and constituted only half of the corresponding range of passive motion. Shoulder girdle muscles were generally weak, only one patient could keep the arm straight in a flexed or abducted position. All patients had returned to their previous occupations, but their ability to perform ADL functions was poor. Rotator cuff insufficiency was considered to be the major cause of poor shoulder function. In comparison to most other surgical alternatives in tumour cases endoprosthetic replacement of the proximal humerus appears to be a safe and reliable method. The endoprosthesis gives stability to the arm and normal elbow and hand function is preserved. PMID:2264717

Olsson, E; Andersson, D; Broström, L A; Wallensten, R; Nilsonne, U

1990-01-01

418

Surgical treatment of complex fracture of the proximal humerus.  

PubMed

Sixteen patients aged 19 to 63 years (average, 52 years) were observed from 1.8 to 5.6 years (average, 3.8 years) after open reduction and internal fixation with or without external fixation of 3- and 4-part displaced fractures of the proximal humerus. There were 12, 3-part displaced greater tuberosity and surgical neck fractures with 6 concomitant dislocations. Four cases were 4-part fractures with 3 concomitant dislocations. Fixation was achieved with heavy sutures or wire that incorporated the rotator cuff tendon, tuberosities, and shaft combined with threaded pins or Hoffmann external fixation to enhanced stability for early rehabilitation. According to Neer's criteria, 14 (87%) of the 16 patients had satisfactory or excellent results. Two (13%) of the 16 had unsatisfactory results. The use of a technique of limited soft tissue dissection and internal fixation with or without external fixation achieved good fracture stability and a high percentage of satisfactory results. The limitations of the procedure include (1) patients who could not tolerate anesthesia, (2) complex displaced fractures in older patients with osteoporotic bone that cannot hold pins or external fixation, (3) older patients with 4-part fracture dislocations in which avascular necrosis of the humeral head occurs frequently and in which a subsequent endoprosthesis insertion is inappropriate if osteosynthesis fails, and (4) head splitting fractures. The described approach provides an alternative method for the treatment of complex displaced fractures of the proximal humerus. PMID:8641068

Ko, J Y; Yamamoto, R

1996-06-01

419

Proximal humeral replacement using a fixed-fulcrum endoprosthesis.  

PubMed

Between 1997 and 2007, 68 consecutive patients underwent replacement of the proximal humerus for tumour using a fixed-fulcrum massive endoprosthesis. Their mean age was 46 years (7 to 87). Ten patients were lost to follow-up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumor Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) at a mean follow-up of five years and 11 months (one year to ten years and nine months). The mean MSTS score was 72.3% (53.3% to 100%) and the mean TESS was 77.2% (58.6% to 100%). Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This subgroup had a mean MSTS score of 77.7% and a mean TESS of 80.0%. The dislocation rate for the original prosthesis was 25.9; none of the patients with the new liner had a dislocation at a mean of 14.5 months (12 to 18). Endoprosthetic replacement for tumours of the proximal humerus using this prosthesis is a reliable operation yielding good results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with a new constrained humeral liner, which reduces the risk of dislocation. PMID:21357964

Griffiths, D; Gikas, P D; Jowett, C; Bayliss, L; Aston, W; Skinner, J; Cannon, S; Blunn, G; Briggs, T W R; Pollock, R

2011-03-01

420

Vision-based proximity detection in retinal surgery.  

PubMed

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, intraocular 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, R; Balicki, M; Sznitman, R; Meisner, E; Taylor, R; Hager, G

2012-08-01

421

An acoustic proximity ranging system for monitoring the cavity thickness.  

PubMed

To control high speed underwater vehicles, a proximity ranging system is needed to monitor the cavity thickness. In this paper, we study a time-of-flight (TOF) principle based acoustic proximity ranging system. By taking into account the acoustically hard boundary at the air-water interface, we first present a two-stage computationally efficient time delay estimation algorithm, referred to as the PEARS (Parameter Estimation for Acoustic Ranging Systems) algorithm, which is applicable to arbitrary transmitted waveforms. Numerical results based on a simulated waveform demonstrate that the PEARS estimates can approach the Cramér-Rao bound as the signal-to-noise ratio increases. We then present experiments performed by using commercially available acoustic transducers to further verify our method. To update TOF estimates quickly, a specially designed continuous wave (CW) is applied to the transducer. Experimental results show that PEARS can achieve high measurement accuracy for ranging distances less than 100 mm with an achievable parameter update rate of approximately 1.5 kHz. PMID:12894923

Li, Xi; Wu, Renbiao; Rasmi, Srihari; Li, Jian; Cattafesta, Louis N; Sheplak, Mark

2003-07-01

422

Group Problem Solving as a Zone of Proximal Development activity  

NASA Astrophysics Data System (ADS)

Vygotsky described learning as a process, intertwined with development, which is strongly influenced by social interactions with others that are at differing developmental stages.i These interactions create a Zone of Proximal Development for each member of the interaction. Vygotsky’s notion of social constructivism is not only a theory of learning, but also of development. While teaching introductory physics in an interactive format, I have found manifestations of Vygotsky’s theory in my classroom. The source of evidence is a paired problem solution. A standard mechanics problem was solved by students in two classes as a homework assignment. Students handed in the homework and then solved the same problem in small groups. The solutions to both the group and individual problem were assessed by multiple reviewers. In many cases the group score was the same as the highest individual score in the group, but in some cases, the group score was higher than any individual score. For this poster, I will analyze the individual and group scores and focus on three groups solutions and video that provide evidence of learning through membership in a Zone of Proximal Development. Endnotes i L. Vygotsky -Mind and society: The development of higher mental processes. Cambridge, MA: Harvard University Press. (1978).

Brewe, Eric

2006-12-01

423

Two Proximal Skin Electrodes -- A Respiration Rate Body Sensor  

PubMed Central

We propose a new body sensor for extracting the respiration rate based on the amplitude changes in the body surface potential differences between two proximal body electrodes. The sensor could be designed as a plaster-like reusable unit that can be easily fixed onto the surface of the body. It could be equipped either with a sufficiently large memory for storing the measured data or with a low-power radio system that can transmit the measured data to a gateway for further processing. We explore the influence of the sensor's position on the quality of the extracted results using multi-channel ECG measurements and considering all the pairs of two neighboring electrodes as potential respiration-rate sensors. The analysis of the clinical measurements, which also include reference thermistor-based respiration signals, shows that the proposed approach is a viable option for monitoring the respiration frequency and for a rough classification of breathing types. The obtained results were evaluated on a wireless prototype of a respiration body sensor. We indicate the best positions for the respiration body sensor and prove that a single sensor for body surface potential difference on proximal skin electrodes can be used for combined measurements of respiratory and cardiac activities.

Trobec, Roman; Rashkovska, Aleksandra; Avbelj, Viktor

2012-01-01

424

Restoring proximal caries lesions conservatively with tunnel restorations.  

PubMed

The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED) and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. PMID:24019754

Chu, Chun-Hung; Mei, May L; Cheung, Chloe; Nalliah, Romesh P

2013-01-01

425

Extracorporeal shock wave lithotripsy of proximal and distal ureteral stones.  

PubMed

Extracorporeal shock wave lithotripsy (ESWL) was used for treatment of 105 patients with ureteral stones. There were 77 stones in the upper part of the ureter, i.e. above the pelvic brim, and 28 in the lower part, i.e. below the sacroiliac joint. Successful fragmentation was attained in 101 (96%). In 93% of the patients with stones in the upper ureter and in 100% with stones in the lower ureter the fragments were eliminated completely. In 87% of the patients with stones in the upper ureter, a ureteral catheter was introduced under local anesthesia but without fluoroscopic control. It was thereby possible to remove 30% of the stones from the ureter to the kidney. For the remaining stones, saline was infused through the catheter during ESWL. For patients with stones in the lower part of the ureter, a ureteral catheter was passed in 79% and saline infused during treatment. Whereas some form of anesthesia was used for treatment of all upper ureteral stones, 89% of the treatments for lower ureteral stones were performed without anesthesia. Auxiliary procedures after ESWL were limited to four ureteral catheter manipulations for distal stones. Four proximal stones which remained unaffected by ESWL had to be treated by open surgery (3 stones) or percutaneous surgery (1 stone). Of 82 ureteric stones treated in situ the success fragmentation rate was 95%. The average number of ESWL sessions was 1.04 for both proximal and distal ureteral stones. PMID:3383929

Pettersson, B; Tiselius, H G

1988-01-01

426

A proximal activator of transcription in epithelial-mesenchymal transition.  

PubMed

Epithelial-mesenchymal transition (EMT) is an important mechanism for phenotypic conversion in normal development and disease states such as tissue fibrosis and metastasis. While this conversion of epithelia is under tight transcriptional control, few of the key transcriptional proteins are known. Fibroblasts produced by EMT express a gene encoding fibroblast-specific protein 1 (FSP1), which is regulated by a proximal cis-acting promoter element called fibroblast transcription site-1 (FTS-1). In mass spectrometry, chromatin immunoprecipitation, and siRNA studies, we used FTS-1 as a unique probe for mediators of EMT and identified a complex of 2 proteins, CArG box-binding factor-A (CBF-A) and KRAB-associated protein 1 (KAP-1), that bind this site. Epithelial cells engineered to conditionally express recombinant CBF-A (rCBF-A) activate the transcription of FSP1 and undergo EMT. The FTS-1 response element also exists in the promoters modulating a broader EMT transcriptome, including Twist, and Snail, as well as E-cadherin, beta-catenin, ZO 1, vimentin, alpha1(I) collagen, and alpha-smooth muscle actin, and the induction of rCBF-A appropriately alters their expression as well. We believe formation of the CBF-A/KAP-1/FTS-1 complex is sufficient for the induction of FSP1 and a novel proximal activator of EMT. PMID:17273560

Venkov, Christo D; Link, Andrew J; Jennings, Jennifer L; Plieth, David; Inoue, Tsutomu; Nagai, Kojiro; Xu, Carol; Dimitrova, Yoana N; Rauscher, Frank J; Neilson, Eric G

2007-02-01

427

Probing nuclear pore complex architecture with proximity-dependent biotinylation.  

PubMed

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, Valérie; Roux, Kyle J

2014-06-17

428

Digital image enhancement improves diagnosis of nondisplaced proximal femur fractures.  

PubMed

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

Botser, Itamar Busheri; Herman, Amir; Nathaniel, Ram; Rappaport, Dan; Chechik, Aharon

2009-01-01

429

Digital Image Enhancement Improves Diagnosis of Nondisplaced Proximal Femur Fractures  

PubMed Central

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.

Herman, Amir; Nathaniel, Ram; Rappaport, Dan; Chechik, Aharon

2008-01-01