Journal articles on the topic 'Sodium flux'
To see the other types of publications on this topic, follow the link: Sodium flux.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Sodium flux.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Flanigan, Michael J. "Sodium Flux and Dialysate Sodium in Hemodialysis." Seminars in Dialysis 11, no. 5 (October 1, 2007): 298–304. http://dx.doi.org/10.1111/j.1525-139x.1998.tb00372.x.
Full text
2
Cappello, Silvia. "Gyrification Needs Correct Sodium Flux!" Neuron 99, no. 5 (September 2018): 867–68. http://dx.doi.org/10.1016/j.neuron.2018.08.005.
Full text
3
Yamane, Hisanori, and Francis J. DiSalvo. "Sodium flux synthesis of nitrides." Progress in Solid State Chemistry 51 (September 2018): 27–40. http://dx.doi.org/10.1016/j.progsolidstchem.2017.08.002.
Full text
4
Edmonds, C. J., and J. Mackenzie. "Sodium transport and the cellular sodium transport pool of colonic epithelium: effects of sodium loading, aldosterone and lithium." Journal of Endocrinology 112, no. 2 (February 1987): 247–52. http://dx.doi.org/10.1677/joe.0.1120247.
Full textAbstract:
ABSTRACT The cellular sodium transport pool and sodium transepithelial fluxes were investigated in vivo in rat distal colon in relation to sodium loading by intravenous infusion (3·5 h), and to short (4 h) and prolonged (72 h) i.v. administration of aldosterone. Considerable natriuresis and increase in body sodium content were produced by the sodium load but there was no significant effect on the transcellular sodium flux (active absorption from lumen to plasma) or on the sodium transport pool. Both short and prolonged aldosteronism produced similar increases in the transport pool and in the transcellular sodium flux, but the transepithelial electrical potential difference (p.d.) was significantly greater in rats given the prolonged infusion. Addition of amiloride to the solution in the lumen of the colon almost completely abolished the p.d., the transport pool and the transcellular sodium flux of the rats receiving prolonged infusion, but had much less effect in those given the short infusion. The time-course of recovery of p.d. following prolonged aldosteronism was similar to that described for the turnover rate of rat colonic epithelial cells. Lithium within the lumen had no significant effect in untreated rats but after prolonged aldosterone infusion lithium reduced the p.d. and the transcellular sodium flux although the transport pool was not reduced. These findings are consistent with the hypothesis that aldosteronism renders the apical membranes of the epithelial cells permeable to lithium and that intracellular accumulation of lithium depresses active sodium transfer. The observations are interpreted in terms of an epithelial model in which aldosterone induces amiloride-sensitive pathways (diffusion channels permeable to sodium and lithium) in the apical membrane which totally replace the amiloride-insensitive pathways when aldosteronism is prolonged; the resulting expansion of the sodium transport pool is the stimulus for increased active sodium transport across the basolateral membranes. J. Endocr. (1987) 112, 247–252
5
Stoos, B. A., N. H. Garcia, and J. L. Garvin. "Nitric oxide inhibits sodium reabsorption in the isolated perfused cortical collecting duct." Journal of the American Society of Nephrology 6, no. 1 (July 1995): 89–94. http://dx.doi.org/10.1681/asn.v6189.
Full textAbstract:
Indirect evidence suggests that nitric oxide inhibits sodium reabsorption by the collecting duct; however, direct evidence is lacking. It was hypothesized that endothelium-derived nitric oxide inhibits sodium flux in the cortical collecting duct by blocking amiloride-sensitive sodium channels. Tubules were obtained from Sprague-Dawley rats pretreated with deoxycorticosterone acetate (5 mg/rat i.m.) 5 to 9 days before the experiment. Nitric oxide was added to the system by either the addition of endothelial cells and the induction of the release of nitric oxide via acetylcholine (10(-7) M) or by the addition of nitric oxide donors. Acetylcholine-induced nitric oxide release from endothelial cells decreased lumen-to-bath sodium flux by 24 +/- 7% (N = 3; P < 0.05). The addition of the nitric oxide donor, spermine NONOate (10(-5) M), decreased net sodium flux 68% from 10.1 +/- 2.0 to 3.6 +/- 2 pmol/mm.min (N = 5; P < 0.025). To assure that the inhibition of sodium flux was due to nitric oxide, another donor, nitroglycerin (2 x 10(-5) M), was used, which decreased sodium flux by 43%. Luminal amiloride (10 microM) decreased net sodium flux by 83% (from 14.8 +/- 1.2 to 2.4 +/- 0.7 pmol/mm.min; N = 5; P < 0.025). The addition of nitric oxide via spermine NONOate to tubules decreased intracellular sodium levels by 26% (N = 6; P < 0.005). The Na(+)-K+ATPase activity of spermine NONOate-treated tubules was 14.7 +/- 3.2 pmol/mm.min compared with the control value of 10.2 +/- 2.0 pmol/mm.min. Nitroglycerin did not significantly affect pump activity either.(ABSTRACT TRUNCATED AT 250 WORDS)
6
Xu, Qing Yang, Lei Ma, Xi Xian Xie, Ning Chen, and Jian Wang. "Impacts of Sodium Citrate on Metabolic Flux Distributions of L-Valine Fermentation." Advanced Materials Research 343-344 (September 2011): 643–48. http://dx.doi.org/10.4028/www.scientific.net/amr.343-344.643.
Full textAbstract:
The effect of sodium citrate on the metabolic flux distributions in the middle and late periods of L-valine production by Corynebacterium glutamicum XV0505 was obtained. It was shown that when sodium citrate (2.0 g/L) was added into the initial fermentation culture medium, the metabolic flux of Embden-Meyerhof-Parnas (EMP) route decreased from 96.43 to 91.13, and the metabolic flux of Hexose Monophophate (HMP) route increased from 3.56 to 8.87, and the metabolic flux flowing to L-alanine and acetate was decreased by 21.1% and 32.4%, respectively. Meanwhile, the metabolic flux of biosynthesis route of L-valine was increased by 10.74%. Therefore, sodium citrate can change the metabolic flux distribution in the key nodes of biosynthesis route of L-valine, decrease the generation of byproducts, and increase the metabolic flux in the biosynthesis route of L-valine.
7
Kim, K. J., and E. D. Crandall. "Sodium-dependent lysine flux across bullfrog alveolar epithelium." Journal of Applied Physiology 65, no. 4 (October 1, 1988): 1655–61. http://dx.doi.org/10.1152/jappl.1988.65.4.1655.
Full textAbstract:
Amino acid transport across the alveolar epithelial barrier was studied by measuring radiolabeled lysine fluxes across bullfrog lungs in an Ussing chamber. In the absence of a transmural electrical gradient, L-[14C]lysine was instilled into the upstream reservoir and the rate of appearance of the radiolabel in the downstream reservoir was determined. Two lungs from the same animal were used simultaneously to determine tracer fluxes both into and out of the alveolar bath. Results showed that the radiolabel flux measured in the alveolar to the pleural direction was greater than that measured in the opposite direction in the presence of sodium in the bathing fluids. The net flux of L-[14C]lysine was saturable with [Na+], with an apparent transport coefficient (Kt) of 28 mM for Na+. Hill analysis of [14C]lysine flux vs. [Na+] indicated a coupling ratio of 1:1 between sodium and radiolabeled L-lysine. Total L-lysine flux as a function of [L-lysine] was also saturable, with Kt of 7.3 mM for L-lysine. Ouabain significantly decreased absorptive (alveolar-to-pleural) radiolabel flux, while slightly increasing the flux observed in the opposite direction. L-leucine completely inhibited absorptive net flux of L-[14C]lysine. alpha-Methylaminoisobutyric acid (MeAIB), on the other hand, only slightly reduced net flux of L-[14C]lysine from the control value. The presence of a net absorptive, Na+-dependent amino acid flux across the alveolar epithelial barrier indicates that the tissue is capable of removing amino acids and sodium from the alveolar fluid by a coupled cotransport mechanism, which may be important for both protein metabolism and fluid balance by alveolar epithelium.
8
Keeler, R., and N. L. Wong. "Evidence that prostaglandin E2 stimulates chloride secretion in cultured A6 renal epithelial cells." American Journal of Physiology-Renal Physiology 250, no. 3 (March 1, 1986): F511—F515. http://dx.doi.org/10.1152/ajprenal.1986.250.3.f511.
Full textAbstract:
The effects of prostaglandin E2 (PGE2) on the transport of sodium and chloride were studied in cultured A6 renal epithelial cells. PGE2 on the basolateral but not the apical surface increased transmonolayer short-circuit current (Isc) and conductance. These changes could not be inhibited with amiloride or furosemide in the apical medium. Flux measurements showed that although Isc and net flux of sodium were equal in unstimulated cells, after addition of PGE2 the current increased with no corresponding changes in bidirectional or net flux of sodium. Immersing the cells in sodium-free or chloride-free media inhibited the effects of PGE2. Measurements of the simultaneous fluxes of sodium and chloride showed that after PGE2 was added there was a net flux of chloride from the basal to the apical side (secretion) that was equal to the change in Isc. The effects of PGE2 were inhibited by furosemide in the basal medium. We conclude that PGE2 stimulates a process of chloride secretion in A6 cells.
9
Schelling, J. R., H. Singh, R. Marzec, and S. L. Linas. "Angiotensin II-dependent proximal tubule sodium transport is mediated by cAMP modulation of phospholipase C." American Journal of Physiology-Cell Physiology 267, no. 5 (November 1, 1994): C1239—C1245. http://dx.doi.org/10.1152/ajpcell.1994.267.5.c1239.
Full textAbstract:
Angiotensin II (ANG II) stimulates proximal tubule sodium transport by decreasing adenylyl cyclase activity. The role of ANG II-dependent phospholipase C is less certain. To determine the contribution of phospholipase C and adenylyl cyclase to apical (AP) ANG II-dependent sodium transport, unidirectional (AP to basolateral) 22Na flux was measured in rat proximal tubule cells cultured on permeable supports. AP ANG II (100 nM)-dependent sodium flux was prevented by preincubation with concentrations of the phospholipase C inhibitor U-73122 (1 microM) that blocked ANG II-dependent inositol phosphate formation. AP ANG II-dependent sodium flux was also abolished by preincubation with the intracellular calcium mobilization inhibitor 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8), further suggesting that ANG II-dependent sodium transport was mediated by inositol phosphates. Neither U-73122 nor TMB-8 prevented ANG II-dependent adenosine 3',5'-cyclic monophosphate (cAMP) decreases. Incubation with dibutyryl cAMP (10 microM) or forskolin (10 microM) prevented ANG II-dependent sodium flux as well as ANG II-dependent inositol phosphate formation. In conclusion, ANG II-dependent proximal tubule sodium transport in cultured cells was transduced by phospholipase C and adenylyl cyclase. The adenylyl cyclase effect on ANG II-dependent sodium transport was mediated by phospholipase C.
10
Al-Alalawy, Ahmed Faiq, Talib Rashid Abbas, and Hadeer Kadhim Mohammed. "Comparative Study for Organic and Inorganic Draw Solutions in Forward Osmosis." Al-Khwarizmi Engineering Journal 13, no. 1 (March 31, 2017): 94–102. http://dx.doi.org/10.22153/kej.2017.08.007.
Full textAbstract:
The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell. Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with respect to water flux. The results showed an increase in water flux with increasing feed temperature and draw solution concentrations In addition, the flux increased with increasing feed flow rate while the flux was inversely proportional with the draw solution flow rate. The results showed that reverse osmosis membranes (TFC and CA) are not suitable for using in FO process due to the relatively obtained low water flux when compared with the flux obtained by forward osmosis membrane (CTA). NaCl draw solution gave higher water flux than other draw solutions and at the same time, revealed higher reverse salt flux.
11
Lee, SunHyung, Katsuya Teshima, Yusuke Mizuno, Kunio Yubuta, Toetsu Shishido, Morinobu Endo, and Shuji Oishi. "Growth of well-developed sodium tantalate crystals from a sodium chloride flux." CrystEngComm 12, no. 10 (2010): 2871. http://dx.doi.org/10.1039/b921092j.
Full text
12
Abely, M., P. Dallet, M. Boisset, and J. F. Desjeux. "Effect of cholera toxin on glutamine metabolism and transport in rabbit ileum." American Journal of Physiology-Gastrointestinal and Liver Physiology 278, no. 5 (May 1, 2000): G789—G796. http://dx.doi.org/10.1152/ajpgi.2000.278.5.g789.
Full textAbstract:
The aim of the present study was to evaluate the effect of cholera toxin on energy balance from intestinal glutamine metabolism and oxidation, glutamine-dependent sodium absorption, and cholera toxin-dependent ion flux. Cholera toxin-stimulated sodium andl-glutamine ileal transport and metabolism were studied in Ussing chambers. Glutamine (10 mM) transport and metabolism were simultaneously studied using 14C flux and HPLC. In the same tissues, the flux of each amino acid was studied by HPLC, and glutamine metabolism and oxidation were studied by the determination of amino acid specific activity and 14CO2production. In control tissues, glutamine stimulated sodium absorption and was mainly oxidized. The transepithelial flux of intact glutamine represented 45% of glutamine flux across the luminal membrane. The other metabolites were glutamate and, to a lesser degree, citrulline, ornithine, and proline. Cholera toxin did not alter glutamine-stimulated sodium absorption, glutamine oxidation, transport, and metabolism. In conclusion, the present results indicate that cholera toxin does not alter glutamine intestinal function and metabolism. In addition, ∼95% of the energy provided by glutamine oxidation remains available to the enterocyte.
13
Vehaskari, V. M. "Ontogeny of cortical collecting duct sodium transport." American Journal of Physiology-Renal Physiology 267, no. 1 (July 1, 1994): F49—F54. http://dx.doi.org/10.1152/ajprenal.1994.267.1.f49.
Full textAbstract:
The postnatal maturation of Na transport in the rabbit cortical collecting duct (CCD) was investigated. CCD segments from rabbits of three different age groups (3-9 days, 10-15 days, and 22-27 days) were perfused in vitro. Lumen-to-bath 22Na fluxes were 38.5 +/- 4.7, 17.0 +/- 2.9, and 30.2 +/- 4.0 pmol.mm-1.min-1 in the three groups, respectively. The high flux in the youngest group was explained by a high passive flux (28.3 +/- 4.2 pmol.mm-1.min-1) determined in the presence of ouabain; the passive 22Na flux in the two other groups (7.1 +/- 2.6 and 3.1 +/- 2.4 pmol.mm-1.min-1) was not significantly different from previously reported adult values. Ouabain-sensitive 22Na flux, reflecting active transport, was low in the two younger groups (10.3 +/- 2.5 and 9.9 +/- 1.9 pmol.mm-1.min-1), but exhibited a rapid increase to 27.1 +/- 2.6 pmol.mm-1.min-1 by 22-27 days of age. In vivo glucocorticoid pretreatment did not affect the Na transport in any age group. Mineralocorticoid pretreatment for 2 days had no effect in the two younger groups, but increased lumen-to-bath 22Na flux from 30.2 +/- 4.0 to 51.1 +/- 4.3 pmol.mm-1.min-1 in the 22- to 27-day-old group. The findings demonstrate that the maturation of rabbit CCD Na transport occurs in two stages, with the first consisting of a decrease in passive permeability during the first 2 wk of life, followed by an increase in active transport and simultaneous development of mineralocorticoid responsiveness.
14
Lamporesi, G., S. Donadello, S. Serafini, and G. Ferrari. "Compact high-flux source of cold sodium atoms." Review of Scientific Instruments 84, no. 6 (June 2013): 063102. http://dx.doi.org/10.1063/1.4808375.
Full text
15
Krishnamra, Nateetip, Yinglak Wirunrattanakij, and Liangchai Limlomwongse. "Acute effects of prolactin on passive calcium absorption in the small intestine by in vivo perfusion technique." Canadian Journal of Physiology and Pharmacology 76, no. 2 (February 1, 1998): 161–68. http://dx.doi.org/10.1139/y97-188.
Full textAbstract:
The acute effect of intraperitoneally administered prolactin (0.2, 0.4, and 0.6 mg/kg body weight) on passive calcium transport in duodenum, proximal jejunum, and ileum of sexually mature female Wistar rats was investigated by using an in vivo perfusion technique. Test solution containing (in mM) NaCl, 100; KCl, 4.7; MgSO4, 1.2; CaCl2, 20; D-glucose, 11; sodium ferrocyanide (Na4Fe(CN)6), an index of net water transport, 20; and 0.7 µCi 45CaCl2 (1 Ci = 37 GBq) was perfused through the 10-cm intestinal loop for 60 min. Results showed that 0.4 mg prolactin/kg body weight significantly increased duodenal net Ca absorption (net Ca) from 23.81 ± 1.84 to 30.56 ± 1.57 mmol/g dry weight (p < 0.05) by stimulating the lumen to plasma calcium flux (CaL-P). The jejunum responded to 0.2, 0.4, and 0.6 mg prolactin/kg body weight by reversing from net Ca absorption of 18.60 ± 1.70 mmol/g dry weight to net secretion of -3.30 ± 1.56, -10.39 ± 2.21, and -11.79 ± 2.04 mmol/g dry weight (p < 0.01), respectively, as a result of a dose-dependent increase in plasma to lumen calcium flux (CaP-L). Calcium fluxes in the ileum on the other hand did not respond to prolactin. There was a close correlation between net water flux and net calcium flux in all three intestinal segments under basal condition regardless of the luminal sodium concentration. However, this correlation was lost after prolactin administration, which while having no effect on net water flux, altered the duodenal and jejunal calcium fluxes. By varying the luminal concentration of sodium, it was found that the stimulatory effect of 0.4 mg prolactin/kg body weight on the duodenal CaL-P was reduced when compared with control, i.e., 17.84 ± 0.91 vs. 26.64 ± 1.05 mmol/g dry weight at a sodium concentration of 180 mM, and 14.48 ± 0.99 vs. 20.12 ± 1.34 mmol/g dry weight at a sodium concentration of 140 mM. At a sodium concentration of 80 mM, the prolactin effect was absent. Since duodenal Na+-K+ ATPase activity was increased by prolactin from 3.77 ± 0.16 to 4.95 ± 0.30 µmol Pi ·mg-1 protein ·h-1 (p < 0.05), sodium dependency of the prolactin-enhanced lumen to plasma calcium flux may be related to both sodium-induced water flow and calcium-sodium exchange across the basolateral membrane. Thus, it was postulated that under basal condition, net calcium transport in the small intestine occurred with the sodium-induced water transport along the paracellular pathway. However, after prolactin administration, this association was lost. Prolactin-enhanced lumen to plasma calcium flux in the duodenum was sodium dependent and involved the Na+-K+ ATPase activity. In the proximal jejunum, prolactin stimulated plasma to lumen calcium flux, but the mechanism was not known.Key words: calcium absorption, calcium fluxes, Na-K ATPase, perfusion technique, prolactin.
16
Popovic, Svetlana, Spasenija Milanovic, Mirela Ilicic, Natasa Lukic, and Ivana Sijacki. "Flux recovery of ceramic tubular membranes fouled with whey proteins: Some aspects of membrane cleaning." Acta Periodica Technologica, no. 39 (2008): 101–9. http://dx.doi.org/10.2298/apt0839101p.
Full textAbstract:
Efficiency of membrane processes is greatly affected by the flux reduction due to the deposits formation at the surface and/or in the pores of the membrane. Efficiency of membrane processes is affected by cleaning procedure applied to regenerate flux. In this work, flux recovery of ceramic tubular membranes with 50 and 200 nm pore size was investigated. The membranes were fouled with reconstituted whey solution for 1 hour. After that, the membranes were rinsed with clean water and then cleaned with sodium hydroxide solutions or formulated detergents (combination of P3 Ultrasil 67 and P3 Ultrasil 69). Flux recovery after the rinsing step was not satisfactory although fouling resistance reduction was significant so that chemical cleaning was necessary. In the case of 50 nm membrane total flux recovery was achieved after cleaning with 1.0% (w/w) sodium hydroxide solution. In the case of 200 nm membrane total flux recovery was not achieved irrespective of the cleaning agent choice and concentration. Cleaning with commercial detergent was less efficient than cleaning with the sodium hydroxide solution.
17
Fukuhara, Y., and R. J. Turner. "Cation dependence of renal outer cortical brush border membrane L-glutamate transport." American Journal of Physiology-Renal Physiology 248, no. 6 (June 1, 1985): F869—F875. http://dx.doi.org/10.1152/ajprenal.1985.248.6.f869.
Full textAbstract:
The cation dependence of L-glutamate transport in renal outer cortical brush border membrane vesicles was studied. Both cis sodium and trans potassium were required for optimal L-glutamate flux. Relative to simultaneous sodium (out greater than in) and potassium (in greater than out) gradient conditions, flux was reduced 50-fold by potassium removal and more than 100-fold by sodium removal. The effect of potassium removal in this preparation was markedly larger than that observed in other renal brush border membrane preparations. No other monovalent cation tested was effective in replacing sodium. However, Rb+ and Cs+ and to a lesser degree NH+4 were found to be effective potassium substitutes. Kinetic analysis of the Na/K-dependent component of L-glutamate flux indicated a single transport system of Km = 13 microM and Vmax = 1.3 nmol X min-1 X mg protein-1. Studies of the dependence of L-glutamate flux on potassium and sodium concentrations yielded Hill coefficients of 0.9 and 1.9, respectively, consistent with involvement of one potassium ion and two or more sodium ions in the L-glutamate transport event. Efflux studies indicated that sodium and potassium act at different steps in the transport cycle, sodium to facilitate the translocation of the glutamate-carrier complex, and potassium to facilitate the return of the unloaded carrier. A model for renal Na/K-dependent L-glutamate transport is suggested on the basis of these results.
18
Schelling, J. R., and S. L. Linas. "Angiotensin II-dependent proximal tubule sodium transport requires receptor-mediated endocytosis." American Journal of Physiology-Cell Physiology 266, no. 3 (March 1, 1994): C669—C675. http://dx.doi.org/10.1152/ajpcell.1994.266.3.c669.
Full textAbstract:
Angiotensin II (ANG II) receptors are present on apical and basolateral surfaces of proximal tubule cells. To determine the cellular mechanisms of proximal tubule ANG II receptor-mediated Na transport, apical-to-basolateral 22Na flux was measured in cultured proximal tubule cells. Apical ANG II caused increases in 22Na flux (maximum response: 100 nM, 30 min). Basolateral ANG II resulted in 22Na flux that was 23-56% greater than 22Na flux observed with equimolar apical ANG II. Apical ANG II-induced 22Na flux was prevented by preincubation with amiloride, ouabain, and the AT1 receptor antagonist losartan. Because apical ANG II signaling was previously shown to be endocytosis dependent, we questioned whether endocytosis was required for ANG II-stimulated proximal tubule Na transport as well. Apical (but not basolateral) ANG II-dependent 22Na flux was inhibited by phenylarsine oxide, an agent which prevents ANG II receptor internalization. In conclusion, apical and basolateral ANG II caused proximal tubule Na transport. Apical ANG II-dependent Na flux was mediated by AT1 receptors, transcellular transport pathways, and receptor-mediated endocytosis.
19
Liu, Jun Xia, Bing Zhi Dong, and Wei Wei Huang. "Characteristics of Fouled and Chemically Cleaned Membrane." Advanced Materials Research 1073-1076 (December 2014): 751–54. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.751.
Full textAbstract:
The main objective of this study was to investigate membrane fouling caused by natural organic matter (NOM). Flux measurement, fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM) were employed to compare the surface morphology of fouled membrane and chemically cleaned membrane. Sodium hypochlorite (NaClO), sodium hydroxide (NaOH), hydrochloric acid (HCl) were used as chemical cleaning agents respectively. Flux analysis demonstrated that chemical cleaning have little effect on flux recovery. FTIR spectrometry revealed that polysaccharide and protein took the major responsibility for membrane fouling. SEM showed that foulants filled the pores and blocked the membrane surface which led to the flux decline.
20
Jacyna, M. R., P. E. Ross, D. Hopwood, and I. A. D. Bouchier. "Sodium transport in the diseased human gallbladder and the effects of indomethacin." Clinical Science 75, no. 2 (August 1, 1988): 147–49. http://dx.doi.org/10.1042/cs0750147.
Full textAbstract:
1. Sodium ion (Na+) transport, a principal function of the gallbladder epithelium, was studied by measuring the flux of 22Na across isolated, inflamed human gallbladder mucosa maintained in a modified ‘Ussing’ flux chamber. Tissue was obtained from cholecystectomy specimens in symptomatic patients with cholelithiasis. 2. In 30 gallbladders studied, 57% had a net Na+ flux from mucosa to serosa (Na+ absorption), while 23% had a net Na+ flux from serosa to mucosa (Na+ secretion). The remaining 20% showed no overall net Na+ flux. 3. Indomethacin added to the serosal fluid reversed the direction of net Na+ flux in secreting gallbladders and caused an absorption of Na+. In Na+-absorbing gallbladders, indomethacin caused a slight reduction in Na+ absorption. No change in Na+ flux was induced in gallbladders with no initial net Na+ flux. 4. These results demonstrate that instead of absorbing Na+, some inflamed human gallbladders may secrete Na+. As this secretion can be reversed to the more usual absorption by indomethacin, it is likely that this secretion is mediated by prostaglandins.
21
YOURAVONG, WIROTE, ALISTAIR S. GRANDISON, and MICHAEL J. LEWIS. "Effect of hydrodynamic and physicochemical changes on critical flux of milk protein suspensions." Journal of Dairy Research 69, no. 3 (August 2002): 443–55. http://dx.doi.org/10.1017/s0022029902005666.
Full textAbstract:
The critical flux during ultrafiltration of whey protein concentrate and sodium caseinate suspensions was investigated. The weak form of critical flux was found for both suspensions. Critical flux of sodium caseinate was higher than that of whey protein concentrate. This could be due to the differences in particle size of the suspensions, resulting in a slower particle back transportation for small particles (whey proteins) compared to the larger casein micelles. Critical flux increased as crossflow velocity increased and decreased as concentration increased, suggesting that critical flux was determined by competition between rate of particle removal from the membrane surface and rate of particle movement towards the membrane surface. Influence of changing pH, addition of NaCl and CaCl2 on the critical fluxes of both protein suspensions was also studied. Increasing pH led to an increase in critical flux for both protein suspensions, suggesting that electrostatic repulsive forces are involved in determining critical flux in both cases. Addition of NaCl gave rise to a decrease in electrostatic interactions due to an increase in ionic strength and ζ potential, and resulted in a decrease in critical flux for sodium caseinate, but had no significant effect for whey protein concentrate. Addition of CaCl2 resulted in a decrease in the critical flux and had a more pronounced influence than NaCl. These results suggest that, in addition to electrostatic repulsive forces, other factors such as structure of protein may be involved in determining the critical flux.
22
Kirschner, L. B. "Proton-sodium flux coupling and apparent saturation of sodium uptake by frog skin." Comparative Biochemistry and Physiology Part A: Physiology 90, no. 4 (January 1988): 833. http://dx.doi.org/10.1016/0300-9629(88)90794-3.
Full text
23
Barnes, Charles, Theodore Tibbitts, John Sager, Gerald Deitzer, David Bubenheim, Gus Koerner, and Bruce Bugbee. "Accuracy of Quantum Sensors Measuring Yield Photon Flux and Photosynthetic Photon Flux." HortScience 28, no. 12 (December 1993): 1197–200. http://dx.doi.org/10.21273/hortsci.28.12.1197.
Full textAbstract:
Photosynthesis is fundamentally driven by photon flux rather than energy flux, but not all absorbed photons yield equal amounts of photosynthesis. Thus, two measures of photosynthetically active radiation have emerged: photosynthetic photon flux (PPF), which values all photons from 400 to 700 nm equally, and yield photon flux (YPF), which weights photons in the range from 360 to 760 nm according to plant photosynthetic response. We selected seven common radiation sources and measured YPF and PPF from each source with a spectroradiometer. We then compared these measurements with measurements from three quantum sensors designed to measure YPF, and from six quantum sensors designed to measure PPF. There were few differences among sensors within a group (usually <5%), but YPF values from sensors were consistently lower (3 % to 20 %) than YPF values calculated from spectroradiometric measurements. Quantum sensor measurements of PPF also were consistently lower than PPF values calculated from spectroradiometric measurements, but the differences were <7% for all sources, except red-light-emitting diodes. The sensors were most accurate for broad-band sources and least accurate for narrow-band sources. According to spectroradiometric measurement, YPF sensors were significantly less accurate (>9% difference) than PPF sensors under metal halide, high-pressure sodium, and low-pressure sodium lamps. Both sensor types were inaccurate (>18% error) under red-light-emitting diodes. Because both YPF and PPF sensors are imperfect integrators, and because spectroradiometers can measure photosynthetically active radiation much more accurately, researchers should consider developing calibration factors from spectroradiometric data for some specific radiation sources to improve the accuracy of integrating sensors.
24
Neal, C. "Assessing environmental impacts on stream water quality: the use of cumulative flux and cumulative flux difference approaches to deforestation of the Hafren Forest, mid-Wales." Hydrology and Earth System Sciences 6, no. 3 (June 30, 2002): 421–32. http://dx.doi.org/10.5194/hess-6-421-2002.
Full textAbstract:
Abstract. A method for examining the impacts of disturbance on stream water quality based on paired catchment "control" and "response" water quality time series is described in relation to diagrams of cumulative flux and cumulative flux difference. The paper describes the equations used and illustrates the patterns expected for idealised flux changes followed by an application to stream water quality data for a spruce forested catchment, the Hore, subjected to clear fell. The water quality determinands examined are sodium, chloride, nitrate, calcium and acid neutralisation capacity. The anticipated effects of felling are shown in relation to reduction in mist capture and nitrate release with felling as well as to the influence of weathering and cation exchange mechanisms, but in a much clearer way than observed previously using other approaches. Keywords: Plynlimon, stream, Hore, acid neutralisation capacity, calcium, chloride, nitrate, sodium, cumulative flux, flux
25
Hashimoto, Shinobu, and Akira Yamaguchi. "Synthesis of α–Al2O3 platelets using sodium sulfate flux." Journal of Materials Research 14, no. 12 (December 1999): 4667–72. http://dx.doi.org/10.1557/jmr.1999.0631.
Full textAbstract:
When powder mixtures of {Al2(SO4)3 + Na2SO4}or {γ–Al2O3 [obtained by heating Al2(SO4)3 at 900 °C for 3 h] + Na2SO4} were heated in an alumina crucible at 1100 °C for 1 h, α–Al2O3 platelets were formed. The powder mixture of {Al2(SO4)3 + 2Na2SO4} yielded aggregations of platelets that were less than 5 μm in size. The size of the aggregations increased in proportion to the amount of Na2SO4, and aggregations of 120 μm were obtained using a mixture of {Al2(SO4)3 + 6Na2SO4}. The powder mixture of {γ–Al2O3 + 2Na2SO4 yielded hexagonal platelets having an average diameter of 3.7 μm and an average thickness of 0.3 μm. In addition to aggregation size, the size of the hexagonal platelets also increased in proportion to the amount of Na2SO4, and platelets having an average diameter of 5 μm were obtained using a mixture of {γ–Al2O3 + 6Na2SO4}.
26
Oishi, Shuji, and Isao Sugiura. "Growth of Chlorapatite Crystals from a Sodium Chloride Flux." Bulletin of the Chemical Society of Japan 70, no. 10 (October 1997): 2483–87. http://dx.doi.org/10.1246/bcsj.70.2483.
Full text
27
Vora, Taira, Ben Corry, and Shin-Ho Chung. "Brownian dynamics study of flux ratios in sodium channels." European Biophysics Journal 38, no. 1 (July 2, 2008): 45–52. http://dx.doi.org/10.1007/s00249-008-0353-5.
Full text
28
Blum, Haywood, Mary D. Osbakken, and Robert G. Johnson. "Sodium flux and bioenergetics in the ischemic rat liver." Magnetic Resonance in Medicine 18, no. 2 (April 1991): 348–57. http://dx.doi.org/10.1002/mrm.1910180209.
Full text
29
Wendler, B., B. Goers, and G. Wozny. "Regeneration of process water containing surfactants by nanofiltration - investigation and modelling of mass transport." Water Science and Technology 46, no. 4-5 (August 1, 2002): 287–92. http://dx.doi.org/10.2166/wst.2002.0607.
Full textAbstract:
The mechanisms in nanofiltration of aqueous solutions of different anionic surfactants and of mixture solutions of surfactants and NaCl are investigated. The surfactants used are sodium dodecylether sulfate, sodium dodecyl sulfate and sodium alkyl benzene sulfonate. High retentions in the range of 95% up to 99.9% referring to the feed concentration are found to depend on the solvent flux. If additional salt is present in the solution, the permeate quality is deteriorating because of lower solvent flux and of mass transfer due to the electrical potential. The experimental results show that convective mass transfer of surfactant through the nanofiltration membrane occurs. Consequently, an extended solution-diffusion model is used for modelling of the process. Depending on the feed composition, concentration polarisation has to be considered in the model. The calculated surfactant flux through the membrane is in good agreement with the experimental results.
30
LUCU, ČEDOMIL, and DIETRICH SIEBERS. "Amiloride-Sensitive Sodium Flux and Potentials in Perfused Carcinus Gill: Preparations." Journal of Experimental Biology 122, no. 1 (May 1, 1986): 25–35. http://dx.doi.org/10.1242/jeb.122.1.25.
Full textAbstract:
Sodium and chloride fluxes, as well as transbranchial potentials (TBP) were studied in isolated perfused gill filaments of the crab Carcinus mediterraneus. Experiments were carried out in media that were either hyposmotic to the perfusion solution (asymmetrical conditions) or isosmotic (symmetrical conditions). Fluxes were found to be diffusional in gills under asymmetrical conditions; amiloride induced an inhibitory effect on influxes, without affecting TBP. Under symmetrical conditions, TBP was −7.6±2.3mV, suggesting that the electrogenic ion pump contributes significantly to the development of TBP. Immediately after addition of 2.5 × 10−4 moll−1 amiloride to the external solution, sodium influxes were reduced to 31% of those in the control group, and TBP was significantly hyperpolarized from −7.6 to −14.8 mV. The absence of Ca2+ under symmetrical conditions diminished TBP hyperpolarization. Half-maximal inhibition of sodium influxes by amiloride was at 7 × 10−5 moll−1. This low amiloride affinity is typical of low resistance leaky epithelia. Sodium transport is discussed as an amiloride-affected influx, probably as a Na/H antiport.
31
Lu, Ming, Yi Bo Yang, Jia Cheng Li, and Wen Ying Guo. "Effects of Reducing Sodium Chloride Concentration on the Results of Coulomb Electric Flux." Key Engineering Materials 477 (April 2011): 388–92. http://dx.doi.org/10.4028/www.scientific.net/kem.477.388.
Full textAbstract:
For reducing the consumption and pollution of the sodium chloride (NaCl), the effect of reducing the NaCl concentration on the result of coulomb electric flux were studied. Three typical proportions of concrete and mortar were used to investigate the effects on the results of coulomb electric flux when the NaCl solution is from 3.0% to 1.0% and 0.5% by mass, respectively. The coulomb electric flux for 6h and 18h and chloride ion penetration depth for18h were studied in this experiment. The results are as followings: (1) it is a little effect on the 6h and 18h coulomb electric flux value of concrete and mortar to use1.0% by mass NaCl solution instead of 3.0% by mass NaCl solution, and the error is less than 5%. It was suitable to use 1.0% NaCl solution by mass. (2)The influence of water-binder ratio (W/B) and test time on coulomb electric flux is related to the porosity and pore connectivity. The lower the W/B, the smaller the coulomb electric flux is; the ratio of coulomb electric flux of 18h to that of 6h was about 2.8 ~ 3.0, and the ratio increases with the water-binder ratio. (3) It is not suitable to use the test results of mortar specimens to count the results of concrete specimens, but can use the results of mortar specimens to estimate the anti-chloride performance of different binder. The suggested test method is that using 0.5% or 1.0% by mass NaCl solution, water-binder ratio is 0.38 and binder-sand ratio is between 1:1.5 and 1:1.8. The best binder-sand ratio and other test parameter need to be determined by more research.
32
Walker, RR. "Sodium Exclusion and Potassium-Sodium Selectivity in Salt-Treated Trifoliate Orange (Poncirus trifoliata) and Cleopatra Mandarin (Citrus reticulata) Plants." Functional Plant Biology 13, no. 2 (1986): 293. http://dx.doi.org/10.1071/pp9860293.
Full textAbstract:
Seedlings of trifoliate orange (Poncirus trifoliata (L.) Raf.) and Cleopatra mandarin (Citrus reticulata Blanco) were grown under glasshouse conditions and supplied with dilute nutrient solution containing 0, 25, 50 or 100 mM NaCl. Trifoliate orange plants grown at 25 or 50 mM NaCl possessed an ability to restrict the accumulation of sodium in leaves. This ability was lost at 100 mM NaCl. For plants treated with 50mM NaCl, uptake of both sodium and chloride per unit root weight was higher for trifoliate orange than for Cleopatra mandarin. Root to leaf transport of chloride was also higher for trifoliate orange, whereas root to leaf transport of sodium was significantly lower. This ability to exclude sodium was unrelated to the flux of water (water flux) per plant, which was similar between the genotypes. Trifoliate orange appeared to possess a greater ability to withdraw sodium from the xylem in the proximal root and basal stem and to sequester it in both the wood and the bark of these regions. This was accompanied by a significant reduction in the concentration of potassium in these tissues, suggesting sodium-potassium exchange. Release of potassium into the xylem in exchange for sodium is implied by the significant increase in leaf potassium concentrations. This ability for sodium exclusion at low to moderate salinities (Ͱ4 50 mM NaCl) enabled trifoliate orange to maintain a relatively constant sodium : potassium ratio in leaves. Salt-treated Cleopatra mandarin plants, on the other hand, tended to show a marginal decrease in leaf potassium concentration and a substantial increase in leaf sodium : potassium ratio. Reducing the mean water flux in trifoliate orange from 38 to 26 �mol s-1 per plant by partial defoliation did not affect root to leaf transport of chloride. However, there was a marked reduction in root to leaf transport of sodium, suggesting an enhanced withdrawal of sodium from the xylem at lower water fluxes.
33
Liu, Jing, Yongqing He, and Xianliang Lei. "Heat-Transfer Characteristics of Liquid Sodium in a Solar Receiver Tube with a Nonuniform Heat Flux." Energies 12, no. 8 (April 14, 2019): 1432. http://dx.doi.org/10.3390/en12081432.
Full textAbstract:
This paper presents a numerical simulation on the heat transfer of liquid sodium in a solar receiver tube, as the liquid sodium is a promising heat-transfer candidate for the next generation solar-power-tower (SPT) system. A comparison between three mediums—solar salt, Hitec and liquid sodium—is presented under uniform and nonuniform heat-flux configurations. We studied the effects of mass flow rate (Qm), inlet temperature (Tin), and maximum heat flux (qomax), on the average heat-transfer coefficient (h) and the friction coefficient (f) of the three mediums. The results show that the h of liquid sodium is about 2.5 to 5 times than other two molten salts when Tin is varying from 550 to 800 K, Qm is 1.0 kg/s, and qomax is 0.1 MW/m2. For maximum heat fluxes from 0.1 to 0.3 MW/m2, the h of liquid sodium is always an order of magnitude larger than that of Hitec and Solar-Salt (S-S), while maintaining a small friction coefficient.
34
Mustafa, Shahzad S., Richard J. Rivers, and Mary D. S. Frame. "Microcirculatory Basis for Nonuniform Flow Delivery with Intravenous Nitroprusside." Anesthesiology 91, no. 3 (September 1, 1999): 723. http://dx.doi.org/10.1097/00000542-199909000-00025.
Full textAbstract:
Background The purpose of this study was to determine the effects of systemic infusions of nitroglycerin and sodium nitroprusside on flow distribution and wall shear stress in the microcirculation. Methods With university approval, the cremaster muscle of 28 anesthetized (70 mg/kg pentobarbital given intraperitoneally) hamsters (Harlan Sprague Dawley: Syrian; weight, 121+/-11 g [mean +/- SDD) was observed using in vivo fluorescence microscopy. Arteriolar diameter, erythrocyte flux, and velocity were measured for a feed arteriole and its sequential branches. Observations were made during control (mean arterial pressure, 88+/-4 mm Hg) and after 30 min of intravenous delivery of sodium nitroprusside or nitroglycerin, titrated to decrease mean arterial pressure by 20 mm Hg. Results Sodium nitroprusside significantly dilated select upstream portions of the network (23+/-2.6 to 29+/-2.6 microm); no arterioles were dilated with nitroglycerin. Erythrocyte flux into the feed (i.e., inflow into the arteriolar network) and into the sequential branches (i.e., distribution within the network) were evaluated. With nitroglycerin, inflow decreased significantly from 1,560+/-335 to 855+/-171 cells/s, and flux into the branches decreased evenly. With sodium nitroprusside, inflow increased significantly to 2,600+/-918 cells/s, yet cells were "stolen" from upstream branches (a decrease from 425+/-67 to 309+/-87 cells/s in the first branch). Excess flow passed into a downstream "thorough-fare channel," significantly increasing flux from 347+/-111 to 761+/-246 cells/s. Wall shear stress decreased uniformly with nitroglycerin infusion, with a decrease in the feed from 8.8+/-2.5 to 6+/-1.7 dyn/cm2. With sodium nitroprusside, variable changes occurred that were location specific within the network. For instance, at the inflow point to the network, wall shear stress changed from 8.3+/-2.5 to 4.2+/-3.3 dyn/cm2. Conclusions Nitroglycerin infusion promoted homogeneity of flow. Sodium nitroprusside significantly increased the heterogeneity of flow within this arteriolar network; an anatomic location for steal induced by sodium nitroprusside is identified.
35
Chiweshe, Trevor T. "Fusion–Extraction Technique of Vanadium(III) Using Ammonium Phosphate Salt as Flux." Crystals 12, no. 10 (October 17, 2022): 1464. http://dx.doi.org/10.3390/cryst12101464.
Full textAbstract:
This study presents an alternative fusion method for sample dissolution and extraction of vanadium from an inorganic (V2O3) compound and mineral ore sample (AMIS 0501) using phosphate salts as flux. Complete sample dissolution was achieved at 800 °C within ±20 min using both the sodium and ammonium phosphate flux. The precipitation of vanadium was subsequently achieved after the fusion of the sample using ammonium phosphate flux, and no precipitate was obtained using sodium phosphate flux. The differences in cations between the two fluxes (NH4+ and Na+) influenced the precipitation of vanadium. The XRD analysis of the precipitate from V2O3 using ammonium phosphate showed a monoclinic structure of vanadium (III) tris(metaphosphate) (V(PO3)3) compound, which belonged to the Ic space group with lattice parameters a = 10.6071, b = 19.0871 and c = 9.4230. A remarkable vanadium recovery of 98% was obtained from inorganic compounds, V2O3, and up to 70% from the AMIS mineral ore sample using the ammonium phosphate flux method. The vanadium precipitates from AMIS contained Fe (20.97%) and Ti (44.97%), which occurred as impurities in the recovery of vanadium using the ammonium phosphate flux method.
36
Milshtein, J., E. Gratz, S. Pati, A. C. Powell, and U. Pal. "Yttria stabilized zirconia membrane stability in molten fluoride fluxes for low-carbon magnesium production by the SOM process." Journal of Mining and Metallurgy, Section B: Metallurgy 49, no. 2 (2013): 183–90. http://dx.doi.org/10.2298/jmmb120809005m.
Full textAbstract:
The Solid Oxide Membrane (SOM) process for magnesium production involves the direct electrolysis of magnesium oxide for energy efficient and low-carbon magnesium production. In the SOM process, magnesium oxide is dissolved in a molten oxy-fluoride flux. An oxygen-ion-conducting SOM tube, made from yttria stabilized zirconia (YSZ), is submerged in the flux. The operating life of the electrolytic cell can be improved by understanding degradation processes in the YSZ, and one way the YSZ degrades is by yttria diffusion out of the YSZ. By adding small amounts of YF3 to the flux, yttria diffusion can be controlled. The diffusion of yttria into the flux was quantified by determining the yttria concentration profile as a function of immersion time in the flux and distance from the flux-YSZ interface. Yttria concentrations were determined using x-ray spectroscopy. The diffusion process was modeled using a numerical approach with an analytic solution to Fick?s second law. These modeling and experimental methods allowed for the determination of the optimum YF3 concentration in the flux to minimize yttria diffusion and improve membrane stability. Furthermore, the effects of common impurities in magnesium ores, such as calcium oxide, silica, and sodium oxide/sodium peroxide, on YSZ stability are being investigated.
37
Stempkowska, Agata. "Silicate Mineral Eutectics with Special Reference to Lithium." Materials 14, no. 15 (August 3, 2021): 4334. http://dx.doi.org/10.3390/ma14154334.
Full textAbstract:
In this paper, the system of natural mineral alkali fluxes used in typical mineral industry technologies was analyzed. The main objective was to reduce the melting temperature of the flux systems. Particular attention was paid to the properties of lithium aluminium silicates in terms of simplifying and accelerating the heat treatment process. In this area, an alkaline flux system involving lithium was analyzed. A basic flux system based on sodium potassium lithium aluminosilicates was analyzed; using naturally occurring raw materials such as spodumene, albite and orthoclase, an attempt was made to obtain the eutectic with the lowest melting point. Studies have shown that there are two eutectics in these systems, with about 30% spodumene content. The active influence of sodium feldspar was found.
38
Oishi, Shuji, Noriyuki Michiba, Nobuo Ishizawa, Juan Carlos Rendon-Angeles, and Kazumichi Yanagisawa. "Growth of Barium Chlorapatite Crystals from a Sodium Chloride Flux." Bulletin of the Chemical Society of Japan 72, no. 9 (September 1999): 2097–101. http://dx.doi.org/10.1246/bcsj.72.2097.
Full text
39
Oishi, Shuji, Mai Mitsuya, Takaomi Suzuki, Nobuo Ishizawa, Juan Carlos Rendon-Angeles, and Kazumichi Yanagisawa. "Growth of Strontium Chlorapatite Crystals from a Sodium Chloride Flux." Bulletin of the Chemical Society of Japan 74, no. 9 (September 2001): 1635–39. http://dx.doi.org/10.1246/bcsj.74.1635.
Full text
40
Blot-Chabaud, M., F. Jaisser, M. Gingold, J. P. Bonvalet, and N. Farman. "Na+-K+-ATPase-dependent sodium flux in cortical collecting tubule." American Journal of Physiology-Renal Physiology 255, no. 4 (October 1, 1988): F605—F613. http://dx.doi.org/10.1152/ajprenal.1988.255.4.f605.
Full textAbstract:
The instantaneous rate of efflux of intracellular Na was studied in rabbit isolated cortical collecting tubules (CCT) as a function of temperature and intracellular Na concentration ([Na]i). [Na]i of microdissected CCT was increased by cold and K-free exposure in the presence of 22Na and the extracellular tracer [3H] sorbitol. [Na]i rose rapidly to 40 mM at 30 min, after which it rose more slowly, reaching 120-140 mM at 6 h. Kinetics of Na efflux were studied after rapid rewarming, using a special device allowing measurements at 20-s intervals. Under control conditions, the total Na load was extruded in less than 8 min, whereas, in the presence of 10(-4) M ouabain, only 50% of the load was extruded during this period of time. Ouabain-sensitive Na efflux was first evident at 13 degrees C and gradually increased between 13 and 35 degrees C. At 37 degrees C, Na+-K+-ATPase-dependent Na efflux was dependent on [Na]i. This efflux gradually increased, from 0.05 to 0.5 peq.nl tubular volume-1.s-1 as a function of [Na]i and reached a plateau at 70 mM [Na]i. It is concluded that [Na]i is a major modulator of the pump activity in CCT; at normal levels of [Na]i, the pump is operating at only a small fraction of its total capacity.
41
Tripathy, A. K., H. S. Ray, and P. K. Pattnayak. "Kinetics of roasting of chromium oxide with sodium nitrate flux." Metallurgical and Materials Transactions B 26, no. 3 (May 1995): 449–54. http://dx.doi.org/10.1007/bf02653861.
Full text
42
Kondratieva, N. P., D. A. Filatov, P. V. Terentiev, and A. S. Al-Helu. "Comparative Assessment of Sodium and LED Greenhouse Irradiators Main Characteristics." Agricultural Machinery and Technologies 14, no. 1 (March 24, 2020): 50–54. http://dx.doi.org/10.22314/2073-7599-2020-14-1-50-54.
Full textAbstract:
The authors showed that traditional sodium greenhouse irradiators are being replaced by more efficient LED ones. (Research purpose) To conduct a comparative assessment of the main characteristics of sodium and LED greenhouse irradiators with an equal photosynthetic photon flux. (Materials and methods) The authors collected a database of 79 sodium irradiators (34 irradiators with electronic ballasts and 45 – with electromagnetic) and 118 – LED. A comparative assessment was carried out in two stages. At the first stage mathematical models of the power, mass, area and cost of irradiation facilities dependence on the photosynthetic photon flux generated by them were obtained. At the second stage the system of equations of sodium and LED greenhouse irradiators for each characteristic were solved. (Results and discussion) The consumed active power of LED irradiators is on average 33 percent less compared to sodium. The area of LED illuminators is 2.5 times larger than sodium irradiators with electronic ballast and 44 percent more than sodium irradiators with electromagnetic ballast. The LED irradiators mass is 3.5 times more than sodium with electronic ballast and 20 percent more than sodium with electromagnetic ballast. The cost of LED illuminators is 3.5 and 4.3 times higher. (Conclusions) LED irradiators are more energy efficient compared to sodium ones. However, due to the high cost, their implementation requires a feasibility study, including additional evaluation criteria: service life, operating costs, electricity price and others.
43
Gorczynska, E., and D. J. Handelsman. "Requirement for transmembrane sodium flux in maintenance of cytosolic calcium levels in rat Sertoli cells." American Journal of Physiology-Endocrinology and Metabolism 264, no. 6 (June 1, 1993): E863—E867. http://dx.doi.org/10.1152/ajpendo.1993.264.6.e863.
Full textAbstract:
The prompt rise in cytosolic calcium induced by follicle-stimulating hormone (FSH) in rat Sertoli cells suggests a role for calcium in FSH signal transduction. To evaluate the requirement for sodium in transmembrane calcium fluxes in Sertoli cells, we measured intracellular calcium concentration under sodium-free conditions and during stimulation by monensin and veratridine, used to elevate cytosolic sodium. Cytosolic calcium levels were measured by dual-wavelength spectrofluorimetry using freshly isolated cells loaded with fura-2 acetoxymethyl ester. Whereas, removal of extracellular sodium lowered cytosolic calcium in unstimulated cells from 89 +/- 4 to 75 +/- 8 nM, treatment with monensin and veratridine increased cytosolic calcium to 142 +/- 19 and 126 +/- 13 nM, respectively. Without extracellular calcium, monensin still produced 47% of the rise in cytosolic calcium observed in the presence of extracellular calcium, indicating approximately equal contributions of calcium from intracellular and extracellular sources. Blockade of voltage-sensitive or/and voltage-insensitive calcium channels by verapamil and ruthenium red was unable to completely prevent the monensin-induced elevation of cytosolic calcium. In addition tetrodotoxin failed to block the FSH-induced rise in cytosolic calcium. These observations, together with the considerable reduction in monensin-induced rise in cytosolic calcium under extracellular sodium-free condition, support the hypothesis that sodium-calcium exchange rather than the specific calcium or sodium channels regulate basal and monensin-induced transmembrane sodium and calcium fluxes in Sertoli cells.
44
Su, Liguo, Richard L. Collins, David A. Krueger, and Chiao-Yao She. "Statistical Analysis of Sodium Doppler Wind–Temperature Lidar Measurements of Vertical Heat Flux." Journal of Atmospheric and Oceanic Technology 25, no. 3 (March 1, 2008): 401–15. http://dx.doi.org/10.1175/2007jtecha915.1.
Full textAbstract:
Abstract A statistical study is presented of the errors in sodium Doppler lidar measurements of wind and temperature in the mesosphere that arise from the statistics of the photon-counting process that is inherent in the technique. The authors use data from the Colorado State University (CSU) sodium Doppler wind-temperature lidar, acquired at a midlatitude site, to define the statistics of the lidar measurements in different seasons under both daytime and nighttime conditions. The CSU lidar measurements are scaled, based on a 35-cm-diameter receiver telescope, to the use of large-aperture telescopes (i.e., 1-, 1.8-, and 3.5-m diameters). The expected biases in vertical heat flux measurements at a resolution of 480 m and 150 s are determined and compared to Gardner and Yang’s reported geophysical values of 2.3 K m s−1. A cross-correlation coefficient of 2%–7% between the lidar wind and temperature estimates is found. It is also found that the biases vary from −4 × 10−3 K m s−1 for wintertime measurements at night with a 3.5-m telescope to −61 K m s−1 for summertime measurements at midday with a 1-m telescope. During winter, at night, the three telescope systems yield biases in their heat flux measurements that are less than 10% of the reported value of the heat flux; and during summer, at night, the 1.8- and 3.5-m systems yield biases in their heat flux measurements that are less than 10% of the geophysical value. While during winter at midday the 3.5-m system yields biases in their heat flux measurements that are less than 10% of the geophysical value, during summer at midday all of the systems yield flux biases that are greater than the geophysical value of the heat flux. The results are discussed in terms of current lidar measurements and proposed measurements at high-latitude sites.
45
Kuwahara, A., S. Bowen, J. Wang, C. Condon, and H. J. Cooke. "Epithelial responses evoked by stimulation of submucosal neurons in guinea pig distal colon." American Journal of Physiology-Gastrointestinal and Liver Physiology 252, no. 5 (May 1, 1987): G667—G674. http://dx.doi.org/10.1152/ajpgi.1987.252.5.g667.
Full textAbstract:
The influence of submucosal neurons on ion transport in the guinea pig distal colon was examined in muscle-stripped sheets of submucosa-mucosa set up in Ussing flux chambers. Spontaneous variations in potential differences (PD) and short-circuit current occurred ranging from positive currents associated with luminal negative PDs to negative currents with luminal positive PDs. Basal current in both groups was reduced by mucosal amiloride. In tissues with positive or negative short-circuit currents, unidirectional mucosal-to-serosal sodium fluxes were greater than serosal-to-mucosal fluxes and small net absorptive fluxes were present. Little or no chloride secretory flux was present. Electrical stimulation of submucosal neurons evoked a tetrodotoxin-sensitive increase in short-circuit current in tissues with positive or negative short-circuit currents. This was due to an increase in net chloride flux and little change in net sodium flux or residual flux. The increase in net chloride flux was due almost entirely to an increase in serosal-to-mucosal chloride flux and was associated with an increase in total tissue conductance. The stimulus-evoked response was reduced by atropine. These results suggest that stimulation of submucosal neurons that innervate the distal colonic epithelium evokes a large chloride secretory response that is due in part to release of acetylcholine at neuro-enterocyte junctions.
46
Bushinsky, D. A., J. M. Goldring, and F. L. Coe. "Cellular contribution to pH-mediated calcium flux in neonatal mouse calvariae." American Journal of Physiology-Renal Physiology 248, no. 6 (June 1, 1985): F785—F789. http://dx.doi.org/10.1152/ajprenal.1985.248.6.f785.
Full textAbstract:
Net calcium flux from cultured neonatal mouse calvariae into the culture medium is pH dependent, and acidified culture medium causes egress of calcium from bone. To determine whether calcium flux is mediated by pH effects on bone cell function, we cultured calvariae for 24 h with sodium azide, acetazolamide, parathyroid hormone (PTH), 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], or after three successive freeze-thaw cycles, treatments that would be expected to alter bone cell function. We recultured bones for 3 h with the respective treatment and measured calcium flux. Sodium azide and freeze-thaw cycles produced a net influx of calcium (JCa = -22 +/- 7 and -23 +/- 6 nmol X bone-1 X 3 h-1, respectively) compared with net efflux of control bones (JCa = 35 +/- 6) at a similar initial medium pH. Acetazolamide reduced net flux to 0 (JCa = 7 +/- 6). PTH and 1,25(OH)2D3 increased net calcium efflux from bone (JCa = 78 +/- 7 and 74 +/- 10, respectively). Despite changing net flux, the slope dependence of net flux on medium pH was the same in the control group and all five treated groups of bones. The similarity of slopes indicates that the pH dependence of net flux is not a result of pH acting on bone cells but probably an effect of altered mineral equilibria. The difference in net flux at similar pH indicates that calcium efflux is partially inhibited by acetazolamide and stimulated by both PTH and 1,25(OH)2D3.
47
Budinger, M. E., E. S. Foster, J. P. Hayslett, and H. J. Binder. "Sodium and chloride transport in the large intestine of potassium-loaded rats." American Journal of Physiology-Gastrointestinal and Liver Physiology 251, no. 2 (August 1, 1986): G249—G252. http://dx.doi.org/10.1152/ajpgi.1986.251.2.g249.
Full textAbstract:
Increased dietary potassium ("potassium loading") induces several adaptive changes in colonic function, including increased potential-dependent potassium secretion, active potassium secretion, and Na-K-ATPase activity, but does not alter net sodium absorption in vivo. To establish whether potassium loading stimulates active sodium transport, unidirectional, net sodium, and chloride fluxes were determined under voltage-clamp conditions across isolated rat distal colonic mucosa. In normal animals net sodium flux (JNanet), net chloride flux (JClnet) and short-circuit current (Isc) were 6.1 +/- 1.1, 8.4 +/- 1.0, and 0.7 +/- 0.1 mu eq X h-1. cm-2, respectively; potassium loading significantly increased JNanet and Isc by 4.9 +/- 1.4 and 3.5 +/- 0.7 mu eq X h-1 X cm-2, respectively, without changing JClnet. Amiloride (0.1 mM) inhibited the increases in JNanet and Isc produced by potassium loading. In Cl-free Ringer solution in normal animals JNanet was reduced to 0.6 +/- 0.3 mu eq X h-1 X cm-2. Potassium loading produced identical increases in JNanet and Isc, which were also completely inhibited by 0.1 mM amiloride. These studies establish that potassium loading induces amiloride-sensitive electrogenic sodium absorption without affecting electroneutral sodium-chloride absorption.
48
Khan, F. A., and D. N. Baron. "Ion flux and Na+,K+-ATPase activity of erythrocytes and leucocytes in thyroid disease." Clinical Science 72, no. 2 (February 1, 1987): 171–79. http://dx.doi.org/10.1042/cs0720171.
Full textAbstract:
1. In hyperthyroidism, erythrocytes show decreased Na+,K+-ATPase activity, decreased [3H]ouabain binding capacity (an index of the number of sodium pumps) and decreased active sodium and potassium flux rates, with a high intracellular sodium concentration. 2. As erythrocytes are non-nucleated and atypical cells, we have studied electrolyte status in thyroid disease using mixed leucocytes as well; the results obtained differed from those in erythrocytes. 3. When compared with findings in healthy subjects, leucocyte Na+,K+-ATPase activity, [3H]-oubain binding capacity, total and active rubidium (used instead of potassium) influx were all significantly increased in untreated hyperthyroidism and decreased in untreated hypothyroidism. 4. In hyperthyroidism, there was also a decrease in plasma potassium, an increase in sodium efflux rate and efflux rate constant, but no significant changes in cell sodium and potassium concentrations. All these changes returned to normal in successfully treated patients. There was a significant correlation between these abnormalities of electrolyte status and thyroid disease status (as serum thyroid stimulating hormone and free thyroxine).
49
Majumder, R., MM Hossain, ME Hossain, and MAR Sarker. "Influence of NaCl on the formation of stoichiometric polycrystalline La0.85Na0.15MnO3." Bangladesh Journal of Scientific and Industrial Research 54, no. 4 (December 30, 2019): 289–96. http://dx.doi.org/10.3329/bjsir.v54i4.44563.
Full textAbstract:
Origination of defects and loss of Na during the sintering process are the major problems for the conventional solid-state synthesis technique to form sodium (Na) doped lanthanum manganite. To minimize defect and Na loss during the sintering process, the sodium (Na) doped lanthanum manganite with 15% substitution of La by Na (La0.85Na0.15MnO3) was synthesized using the NaCl flux material incorporated with the conventional solid-state reaction technique (flux method). The amount of micro strain, lattice strain and dislocation density for the flux method to grow polycrystalline La0.85Na0.15MnO3were detected successfully. The structural study using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Analysis X-Ray (EDAX) showed that the use of flux synthesis technique instead of conventional solid-state reaction technique was satisfactory to obtain stoichiometric La0.85Na0.15MnO3 polycrystalline structure with a smaller defect. From the closer inspection of the XRD spectrum for La0.85Na0.15MnO3 significantly showed a higher order layered structure for the cathode material for using this flux technique, which is a very important feature to increase the efficiency of the cathode material.
Bangladesh J. Sci. Ind. Res.54(4), 289-296, 2019
50
Hellemeier, J., M. Enderlein, M. Hager, D. Bonaccini Calia, R. L. Johnson, F. Lison, M. O. Byrd, L. A. Kann, M. Centrone, and P. Hickson. "Laser guide star return-flux gain from frequency chirping." Monthly Notices of the Royal Astronomical Society 511, no. 3 (February 9, 2022): 4660–68. http://dx.doi.org/10.1093/mnras/stac343.
Full textAbstract:
ABSTRACT Spectral hole burning reduces sodium laser guide star efficiency. Due to photon recoil, atoms that are initially resonant with the single-frequency laser get Doppler shifted out of resonance, which reduces the return flux. Frequency-chirped (also known as frequency-swept) continuous-wave lasers have the potential to mitigate the effect of spectral hole burning and even increase the laser guide star efficiency beyond the theoretical limit of a single-frequency laser. We investigate the return flux of frequency-chirped laser guide stars and its dependence on environmental and chirping parameters. On-sky measurements of a frequency-chirped, single-frequency laser guide star are performed at the Roque de los Muchachos Observatory on La Palma. A fast photon-counting receiver system is employed to resolve the return-flux response during laser frequency sweeps gaining insights into the population dynamics of the sodium layer. At a launched laser power of 16.5 W, we find a maximum gain in return flux of 22 per cent compared to a fixed-frequency laser at a chirping amplitude of the order of 150 MHz and a chirping rate of 0.8 MHz µs−1. Time-resolved measurements during the chirping period confirm our understanding of the population dynamics in the sodium layer. These are the first measurements of return-flux enhancement for laser guide stars excited by a single-frequency-chirped continuous-wave laser. For higher laser powers, the effectiveness of chirping is expected to increase, which could be highly beneficial for telescopes equipped with high-power laser guide star adaptive optics systems.