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Sample records for activate kcl cotransport

  1. ROS activate KCl cotransport in nonadherent Ehrlich ascites cells but K+ and Cl- channels in adherent Ehrlich Lettré and NIH3T3 cells

    Lambert, Ian Henry; Klausen, Thomas Kjær; Bergdahl, Andreas;

    2009-01-01

    Addition of H2O2 (0.5 mM) to Ehrlich ascites tumor cells under isotonic conditions results within 25 min in a substantial (22 +/- 1 %) reduction in cell volume. The cell shrinkage is paralleled by net loss of K(+), which was significant within 8 min, whereas no concomitant increase in the K(+) or...... the electrochemical driving force for K(+). On the other hand, the H2O2-induced cell shrinkage was impaired in the presence of the KCl cotransport inhibitor DIOA, following substitution of NO3(-) for Cl(-), and when the driving force for KCl cotransport was omitted. It is suggested that H2O2 activates...... electro neutral KCl cotransport in Ehrlich ascites tumor cells and not K(+) and Cl(-) channels. Addition of H2O2 to hypotonically exposed cells accelerates the regulatory volume decrease and the concomitant net loss of K(+), whereas no additional increase in the K(+) and Cl(-) conductance was observed...

  2. Current view on the functional regulation of the neuronal K+-Cl- cotransporter KCC2

    Igor Medina

    2014-02-01

    Full Text Available In the mammalian central nervous system, the inhibitory strength of chloride (Cl--permeable GABAA and glycine receptors (GABAAR and GlyR depends on the intracellular Cl- concentration ([Cl-]i. Lowering [Cl-]i enhances inhibition, whereas raising [Cl-]i facilitates neuronal activity. A neuron’s basal level of [Cl-]i, as well as its Cl- extrusion capacity, is critically dependent on the activity of the electroneutral K+-Cl- cotransporter KCC2, a member of the SLC12 cation-Cl- cotransporter (CCC family. KCC2 deficiency compromises neuronal migration, formation and the maturation of GABAergic and glutamatergic synaptic connections, and results in network hyperexcitability and seizure activity. Several neurological disorders including multiple epilepsy subtypes, neuropathic pain, and schizophrenia, as well as various insults such as trauma and ischemia, are associated with significant decreases in the Cl- extrusion capacity of KCC2 that result in increases of [Cl-]i and the subsequent hyperexcitability of neuronal networks. Accordingly, identifying the key upstream molecular mediators governing the functional regulation of KCC2, and modifying these signalling pathways with small molecules, might constitute a novel neurotherapeutic strategy for multiple diseases. Here, we discuss recent advances in the understanding of the mechanisms regulating KCC2 activity, and of the role these mechanisms play in neuronal Cl- homeostasis and GABAergic neurotransmission. As KCC2 mediates electroneutral transport, the experimental recording of its activity constitutes an important research challenge; we therefore also, provide an overview of the different methodological approaches utilized to monitor function of KCC2 in both physiological and pathological conditions.

  3. Loss of K-Cl co-transporter KCC3 causes deafness, neurodegeneration and reduced seizure threshold.

    Boettger, Thomas; Rust, Marco B; Maier, Hannes; Seidenbecher, Thomas; Schweizer, Michaela; Keating, Damien J; Faulhaber, Jörg; Ehmke, Heimo; Pfeffer, Carsten; Scheel, Olaf; Lemcke, Beate; Horst, Jürgen; Leuwer, Rudolf; Pape, Hans-Christian; Völkl, Harald; Hübner, Christian A; Jentsch, Thomas J

    2003-10-15

    K-Cl co-transporters are encoded by four homologous genes and may have roles in transepithelial transport and in the regulation of cell volume and cytoplasmic chloride. KCC3, an isoform mutated in the human Anderman syndrome, is expressed in brain, epithelia and other tissues. To investigate the physiological functions of KCC3, we disrupted its gene in mice. This severely impaired cell volume regulation as assessed in renal tubules and neurons, and moderately raised intraneuronal Cl(-) concentration. Kcc3(-/-) mice showed severe motor abnormalities correlating with a progressive neurodegeneration in the peripheral and CNS. Although no spontaneous seizures were observed, Kcc3(-/-) mice displayed reduced seizure threshold and spike-wave complexes on electrocorticograms. These resembled EEG abnormalities in patients with Anderman syndrome. Kcc3(-/-) mice also displayed arterial hypertension and a slowly progressive deafness. KCC3 was expressed in many, but not all cells of the inner ear K(+) recycling pathway. These cells slowly degenerated, as did sensory hair cells. The present mouse model has revealed important cellular and systemic functions of KCC3 and is highly relevant for Anderman syndrome. PMID:14532115

  4. Regulated phosphorylation of the K-Cl cotransporter KCC3 at dual C-terminal threonines is a potent switch of intracellular potassium content and cell volume homeostasis

    Norma C. Adragna

    2015-07-01

    Full Text Available The defense of cell volume against excessive shrinkage or swelling is a requirement for cell function and organismal survival. Cell swelling triggers a coordinated homeostatic response termed regulatory volume decrease (RVD, resulting in K+ and Cl– efflux via the activation of K+ channels, volume-regulated anion channels (VRACs, and the K+-Cl– cotransporters, including KCC3. Here, we show genetic alanine (Ala substitution at threonines (Thr 991 and 1048 in the KCC3a isoform carboxyl-terminus, preventing inhibitory phosphorylation at these sites, not only significantly up-regulates KCC3a activity up to 25-fold in normally inhibitory isotonic conditions, but is also accompanied by reversal of activity of the related bumetanide-sensitive Na+-K+-2Cl– cotransporter isoform 1 (NKCC1. This results in a rapid (90 % reduction in intracellular K+ content (Ki via both Cl-dependent (KCC3a + NKCC1 and Cl-independent (DCPIB [VRAC inhibitor]-sensitive pathways, which collectively renders cells less prone to acute swelling in hypotonic osmotic stress. Together, these data demonstrate the phosphorylation state of Thr991/Thr1048 in the KCC3a encodes a potent switch of transporter activity, Ki homeostasis, and cell volume regulation, and reveal novel observations into the functional interaction among ion transport molecules involved in RVD.

  5. Absence of Na +/sugar cotransport activity in Barrett's metaplasia

    Lisa J Murray; Owen Tully; David S Rudolph; Marysue Whitby; Mary C Valenzano; Giancarlo Mercogliano; James J Thornton; James M Mullin

    2008-01-01

    AIM:To evaluate the presence of Na+-dependent,active,sugar transport in Barrett's epithelia as an intestinal biomarker,based on the well-documented,morphological intestinal phenotype of Barrett's esophagus (BE).METHODS:We examined uptake of the nonmeta-bolizable glucose analogue,alpha-methyl-D-glucoside (AMG),a substrate for the entire sodium glucose cotransporter (SGLT) family of transport proteins.During upper endoscopy,patients with BE or with uncomplicated gastroesophageal reflux disease (GERD)allowed for duodenal,gastric fundic,and esophageal mucosal biopsies to be taken.Biopsies were incubated in bicarbonate-buffered saline (KRB) containing 0.1 mmol/L 14C-AMG for 60 min at 20℃.Characterized by abundant SGLT,duodenum served as a positive control while gastric fundus and normal esophagus,known to lack SGLT,sewed as negative controls.RESULTS:Duodenal biopsies accumulated 249.84± 35.49 (SEM) picomoles AMG/μg DNA (n = 12),gastric fundus biopsies 36.20 ± 6.62 (n = 12),normal esophagus 12.10 ± 0.59 (n = 3) and Barrett's metaplasia 29.79 ± 5.77 (n = 8).There was a statistical difference (P<0.01) between biopsies from duodenum and each other biopsy site but there was no statistically significant difference between normal esophagus and BE biopsies.0.5 mmol/L phlorizin (PZ) inhibited AMG uptake into duodenal mucosa by over 89%,but had no significant effect on AMG uptake into gastric fundus,normal esophagus,or Barrett's tissue.In the absence of Na+ (all Na+ salts replaced by Li+ salts),AMG uptake in duodenum was decreased by over 90%,while uptake into gastric,esophageal or Barrett's tissue was statistically unaffected.CONCLUSION:Despite the intestinal enterocyte phenotype of BE,Na+-dependent,sugar transport activity is not present in bhese cells.

  6. Glucocorticoids Induce Nondipping Blood Pressure by Activating the Thiazide-Sensitive Cotransporter.

    Ivy, Jessica R; Oosthuyzen, Wilna; Peltz, Theresa S; Howarth, Amelia R; Hunter, Robert W; Dhaun, Neeraj; Al-Dujaili, Emad A S; Webb, David J; Dear, James W; Flatman, Peter W; Bailey, Matthew A

    2016-05-01

    Blood pressure (BP) normally dips during sleep, and nondipping increases cardiovascular risk. Hydrochlorothiazide restores the dipping BP profile in nondipping patients, suggesting that the NaCl cotransporter, NCC, is an important determinant of daily BP variation. NCC activity in cells is regulated by the circadian transcription factor per1. In vivo, circadian genes are entrained via the hypothalamic-pituitary-adrenal axis. Here, we test whether abnormalities in the day:night variation of circulating glucocorticoid influence NCC activity and BP control. C57BL6/J mice were culled at the peak (1:00 AM) and trough (1:00 PM) of BP. We found no day:night variation in NCC mRNA or protein but NCC phosphorylation on threonine(53)(pNCC), required for NCC activation, was higher when mice were awake, as was excretion of NCC in urinary exosomes. Peak NCC activity correlated with peak expression of per2 and bmal1 (clock genes) and sgk1 and tsc22d3 (glucocorticoid-responsive kinases). Adrenalectomy reduced NCC abundance and blunted the daily variation in pNCC levels without affecting variation in clock gene transcription. Chronic corticosterone infusion increased bmal1, per1, sgk1, and tsc22d3 expression during the inactive phase. Inactive phase pNCC was also elevated by corticosterone, and a nondipping BP profile was induced. Hydrochlorothiazide restored rhythmicity of BP in corticosterone-treated mice without affecting BP in controls. Glucocorticoids influence the day:night variation in NCC activity via kinases that control phosphorylation. Abnormal glucocorticoid rhythms impair NCC and induce nondipping. Night-time dosing of thiazides may be particularly beneficial in patients with modest glucocorticoid excess. PMID:26953322

  7. Oxidative stability and antioxidant enzyme activities of dry-cured bacons as affected by the partial substitution of NaCl with KCl.

    Wu, Haizhou; Yan, Wenjing; Zhuang, Hong; Huang, Mingming; Zhao, Jianying; Zhang, Jianhao

    2016-06-15

    This study investigated the influence of partial substitution of NaCl with KCl on protein and lipid oxidation as well as antioxidant enzyme activities in dry-cured bacons during processing. The partial substitution was 0% KCl (I), 40% KCl (II), and 70% KCl (III). Compared with 0% KCl (I), the substitution of 40% NaCl with KCl did not significantly influence the protein and lipid oxidation and antioxidant enzyme activities. The bacons that were treated with 70% KCl treatment (III) showed increased lipid oxidation and antioxidant enzyme GSH-Px activity, whereas samples treated with formulas I and II showed higher protein oxidation and antioxidant enzyme catalase activity. These results demonstrate that the substitution of NaCl with KCl by more than 40% may significantly affect protein and lipid oxidation and that for the substitution of NaCl in further processed meat products with other chloride salts, salt content is very important for control of protein and lipid biochemical changes in finished products. PMID:26868571

  8. Tracers for monitoring the activity of sodium/glucose cotransporters in health and disease

    Wright, Ernest M; Barrio, Jorge R; Hirayama, Bruce A; Kepe, Vladimir

    2014-09-30

    Radiolabeled tracers for sodium/glucose cotransporters (SGLTs), their synthesis, and their use are provided. The tracers are methyl or ethyl pyranosides having an equatorial hydroxyl group at carbon-2 and a C 1 preferred conformation, radiolabeled with .sup.18F, .sup.123I, or .sup.124I, or free hexoses radiolabeled with .sup.18F, .sup.123I, or .sup.124. Also provided are in vivo and in vitro techniques for using these and other tracers as analytical and diagnostic tools to study glucose transport, in health and disease, and to evaluate therapeutic interventions.

  9. The role of activator concentration and precipitate formation on optical and dosimetric properties of KCl:Eu{sup 2+} storage phosphor detectors

    Hansel, Rachael A.; Xiao, Zhiyan; Hu, Yanle; Green, Olga; Yang, Deshan; Harold Li, H. [Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States)

    2013-09-15

    Purpose: The activator ion (Eu{sup 2+} in KCl:Eu{sup 2+}) plays an important role in the photostimulated luminescence (PSL) mechanism of storage phosphor radiation detectors. In order to design an accurate, effective, and robust detector, it is important to understand how the activator ion concentration affects the structure and, consequently, radiation detection properties of KCl:Eu{sup 2+}.Methods: Potassium chloride pellets were fabricated with various amounts of europium dopant (0.01–5.0 mol.% Eu{sup 2+}). Clinical radiation doses were given with a 6 MV linear accelerator. Radiation doses larger than 100 Gy were given with a {sup 137}Cs irradiator. Dose response curves, radiation hardness, and temporal signal stability were measured using a laboratory PSL readout system. The crystal structure of the material was studied using x ray diffraction and luminescence spectroscopy.Results: The most intense PSL signal was from samples with 1.0 mol.% Eu. However, samples with concentrations higher than 0.05 mol.% Eu exhibited significant degradation in PSL intensity for cumulated doses larger than 3000 Gy. Structural and luminescence spectroscopy showed clear evidence of precipitate phases within the KCl lattice, especially for high activator concentrations. Analysis of PL emission spectra showed that interactions between Eu-V{sub c} dipoles and Eu-V{sub c} trimers could explain trends in PSL sensitivity and radiation hardness observations.Conclusions: The concentration of the activator ion (Eu{sup 2+}) significantly affects radiation detection properties of the storage phosphor KCl:Eu{sup 2+}. An activator concentration between 0.01 and 0.05 mol.% Eu in KCl:Eu{sup 2+} storage phosphor detectors is recommended for linear dose response, good PSL sensitivity, predictable temporal stability, and high reusability for megavoltage radiation detection.

  10. Expression of apical Na(+)-L-glutamine co-transport activity, B(0)-system neutral amino acid co-transporter (B(0)AT1) and angiotensin-converting enzyme 2 along the jejunal crypt-villus axis in young pigs fed a liquid formula.

    Yang, Chengbo; Yang, Xiaojian; Lackeyram, Dale; Rideout, Todd C; Wang, Zirong; Stoll, Barbara; Yin, Yulong; Burrin, Douglas G; Fan, Ming Z

    2016-06-01

    Gut apical amino acid (AA) transport activity is high at birth and during suckling, thus being essential to maintain luminal nutrient-dependent mucosal growth through providing AA as essential metabolic fuel, substrates and nutrient stimuli for cellular growth. Because system-B(0) Na(+)-neutral AA co-transporter (B(0)AT1, encoded by the SLC6A19 gene) plays a dominant role for apical uptake of large neutral AA including L-Gln, we hypothesized that high apical Na(+)-Gln co-transport activity, and B(0)AT1 (SLC6A19) in co-expression with angiotensin-converting enzyme 2 (ACE2) were expressed along the entire small intestinal crypt-villus axis in young animals via unique control mechanisms. Kinetics of Na(+)-Gln co-transport activity in the apical membrane vesicles, prepared from epithelial cells sequentially isolated along the jejunal crypt-villus axis from liquid formula-fed young pigs, were measured with the membrane potential being clamped to zero using thiocyanate. Apical maximal Na(+)-Gln co-transport activity was much higher (p < 0.05) in the upper villus cells than in the middle villus (by 29 %) and the crypt (by 30 %) cells, whereas Na(+)-Gln co-transport affinity was lower (p < 0.05) in the upper villus cells than in the middle villus and the crypt cells. The B(0)AT1 (SLC6A19) mRNA abundance was lower (p < 0.05) in the crypt (by 40-47 %) than in the villus cells. There were no significant differences in B(0)AT1 and ACE2 protein abundances on the apical membrane among the upper villus, the middle villus and the crypt cells. Our study suggests that piglet fast growth is associated with very high intestinal apical Na(+)-neutral AA uptake activities via abundantly co-expressing B(0)AT1 and ACE2 proteins in the apical membrane and by transcribing the B(0)AT1 (SLC6A19) gene in the epithelia along the entire crypt-villus axis. PMID:26984322

  11. Cotransporters as molecular water pumps

    Zeuthen, Thomas; MacAulay, Nanna

    2002-01-01

    for such cotransport can be ruled out for both experimental and theoretical reasons. Indeed, substrate fluxes mediated by channels or ionophores generate much smaller water fluxes than those observed with cotransporters. Theoretical models, using reasonable values for the intracellular diffusion coefficient, indicate...

  12. Isopiestic determination of the osmotic and activity coefficients of the {yKCl + (1 - y)K2HPO4}(aq) system at T = 298.15 K

    Highlights: → Isopiestic measurements were made for {yKCl + (1 - y)K2HPO4}(aq) at T = 298.15 K. → The resulting osmotic coefficients were represented by three thermodynamic models. → Activity coefficients from Pitzer model with Scatchard mixing terms are recommended. - Abstract: The osmotic coefficients of aqueous mixtures of KCl and K2HPO4 have been measured at T = (298.15 ± 0.01) K by the isopiestic vapor pressure method over the range of ionic strengths from (2.3700 to 11.250) mol . kg-1 using CaCl2(aq) as the reference solution. Our new experimental results were modeled with an extended form of Pitzer's ion-interaction model equations, both with the usual mixing terms and with Scatchard's neutral-electrolyte mixing terms, and with the Clegg-Pitzer-Brimblecombe equations based on the mole-fraction-composition scale. There is a dearth of previously published isopiestic data for mixtures containing salts of HPO42-(aq) and, consequently, no previous measurements are available for comparison with the present results. The present study yields Cl-HPO42- mixing parameters for these three models that are needed for modeling the thermodynamic activities of solute components of natural waters and other complex aqueous electrolyte mixtures.

  13. Peripheral motor neuropathy is associated with defective kinase regulation of the KCC3 cotransporter.

    Kahle, Kristopher T; Flores, Bianca; Bharucha-Goebel, Diana; Zhang, Jinwei; Donkervoort, Sandra; Hegde, Madhuri; Hussain, Gulnaz; Duran, Daniel; Liang, Bo; Sun, Dandan; Bönnemann, Carsten G; Delpire, Eric

    2016-01-01

    Using exome sequencing, we identified a de novo mutation (c.2971A>G; T991A) in SLC12A6, the gene encoding the K(+)-Cl(-) cotransporter KCC3, in a patient with an early-onset, progressive, and severe peripheral neuropathy primarily affecting motor neurons. Normally, the WNK kinase-dependent phosphorylation of T(991) tonically inhibits KCC3; however, cell swelling triggers Thr(991) dephosphorylation to activate the transporter and restore cell volume. KCC3 T991A mutation in patient cells abolished Thr(991) phosphorylation, resulted in constitutive KCC3 activity, and compromised cell volume homeostasis. KCC3(T991A/T991A) mutant mice exhibited constitutive KCC3 activity and recapitulated aspects of the clinical, electrophysiological, and histopathological findings of the patient. These results suggest that the function of the peripheral nervous system depends on finely tuned, kinase-regulated KCC3 activity and implicate abnormal cell volume homeostasis as a previously unreported mechanism of axonal degeneration. PMID:27485015

  14. Functional Role of Glucose Metabolism, Osmotic Stress, and Sodium-Glucose Cotransporter Isoform-Mediated Transport on Na+/H+ Exchanger Isoform 3 Activity in the Renal Proximal Tubule

    Pessoa, Thaissa Dantas; Campos, Luciene Cristina Gastalho; Carraro-Lacroix, Luciene; Girardi, Adriana C. C.; Malnic, Gerhard

    2014-01-01

    Na+-glucose cotransporter 1 (SGLT1)-mediated glucose uptake leads to activation of Na+-H+ exchanger 3 (NHE3) in the intestine by a process that is not dependent on glucose metabolism. This coactivation may be important for postprandial nutrient uptake. However, it remains to be determined whether SGLT-mediated glucose uptake regulates NHE3-mediated NaHCO3 reabsorption in the renal proximal tubule. Considering that this nephron segment also expresses SGLT2 and that the kidneys and intestine sh...

  15. Modeling glial contributions to seizures and epileptogenesis: cation-chloride cotransporters in Drosophila melanogaster.

    Zeid M Rusan

    Full Text Available Flies carrying a kcc loss-of-function mutation are more seizure-susceptible than wild-type flies. The kcc gene is the highly conserved Drosophila melanogaster ortholog of K+/Cl- cotransporter genes thought to be expressed in all animal cell types. Here, we examined the spatial and temporal requirements for kcc loss-of-function to modify seizure-susceptibility in flies. Targeted RNA interference (RNAi of kcc in various sets of neurons was sufficient to induce severe seizure-sensitivity. Interestingly, kcc RNAi in glia was particularly effective in causing seizure-sensitivity. Knockdown of kcc in glia or neurons during development caused a reduction in seizure induction threshold, cell swelling, and brain volume increase in 24-48 hour old adult flies. Third instar larval peripheral nerves were enlarged when kcc RNAi was expressed in neurons or glia. Results suggest that a threshold of K+/Cl- cotransport dysfunction in the nervous system during development is an important determinant of seizure-susceptibility in Drosophila. The findings presented are the first attributing a causative role for glial cation-chloride cotransporters in seizures and epileptogenesis. The importance of elucidating glial cell contributions to seizure disorders and the utility of Drosophila models is discussed.

  16. Differentiation-dependent expression of the Na+/glucose cotransporter (SGLT1) in LLC-PK1 cells: role of protein kinase C activation and ongoing transcription.

    Shioda, T; Ohta, T.(Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan); Isselbacher, K J; Rhoads, D B

    1994-01-01

    We examined changes in the mRNA level of SGLT1, a Na+/glucose cotransporter, by the differentiation status of LLC-PK1 renal epithelial cells. Proliferating (undifferentiated) cells revealed no detectable SGLT1 mRNA by Northern blot analysis. However, when cells became confluent and differentiated into polarized monolayers, there was an abrupt appearance of the SGLT1 mRNA. When confluent (differentiated) cells were dedifferentiated by reseeding at a subconfluent density, SGLT1 mRNA levels decr...

  17. Water permeability of Na+-K+-2C1- cotransporters in mammalian epithelial cells

    Hammann, Steffen; Herrera-Perez, J.J.; Bundgaard, Magnus;

    2005-01-01

    Water transport properties of the Na+-K+-2Cl- cotransporter (NKCC) were studied in cultures of pigmented epithelial cells (PE) from the ciliary body of the eye. Here, the membrane that faces upwards contains NKCCs and can be subjected to rapid changes in bathing solution composition and osmolarity....... The anatomy of the cultured cell layer was investigated by light and electron microscopy. The transport rate of the cotransporter was determined from the bumetanide-sensitive component of 86Rb+ uptake, and volume changes were derived from quenching of the fluorescent dye calcein. The water...... permeability (Lp) of the membrane was halved by the specific inhibitor bumetanide. The bumetanide-sensitive component of the water transport exhibited apparent saturation at osmotic gradients higher than 200 mosmol l-1. Cell shrinkages produced by NaCl or KCl were smaller than those elicited by equi...

  18. Regulation of the sodium/potassium/chloride cotransporter by calcium and cyclic AMP in cultured vascular smooth muscle cells

    Higgins, B.L.; Smith, L.; Smith, J.B.

    1987-05-01

    The activity of the Na/K/Cl cotransporter in smooth muscle cells cultured from rat aorta was assayed by measuring the initial rate of furosemide-inhibitable /sup 86/Rb influx or efflux. Five uM furosemide or 0.2 uM bumetanide inhibited influx by 50%. Furosemide-inhibitable /sup 86/Rb influx depended on the presence of all 3 ions in the external medium. The dependence on Na and K was hyperbolic with apparent Km values of 45 and 5 mM, respectively. The dependence on Cl was sigmoidal. Assuming a stoichiometry of 1:1:2 for Na:K:Cl, a Km for Cl of 60 mM was obtained from a Hofstee plot of the data. Rapidly growing cells had 3 fold higher cotransport activity than quiescent cells. Angiotensin II (ANG) stimulated furosemide-inhibitable /sup 86/Rb efflux by 2 fold. An ANG receptor antagonist prevented ANG from increasing cotransport activity. Two calcium ionophores, A23187 and ionomycin, increased cotransport activity by 2 fold. Phorbol myristate acetate had no effect on cotransport activity. Isoproterenol, dibutyryl cyclic AMP, cholera toxin, or methylisobutylxanthine inhibited furosemide-sensitive /sup 86/Rb influx by 35 to 50%. From these findings they conclude that increasing cytoplasmic free calcium stimulates cotransport activity, whereas increasing cellular cyclic AMP inhibits the cotransporter.

  19. K-Cl transport systems in rabbit renal basolateral membrane vesicles

    The transport pathways for chloride in basolateral membrane vesicles from the rabbit renal cortex were investigated. 36Cl uptake was stimulated by the presence of potassium in the uptake media compared with sodium of N-methyl-D-glucamine. In addition, potassium (86Rb) uptake was stimulated more by chloride than by nitrate or gluconate. Neither of these processes was further stimulated by potassium gradients plus valinomycin, suggesting the presence of an electrically neutral K-Cl cotransport system. A magnesium-induced chloride conductance was also found in the basolateral membrane vesicles. In the absence of magnesium, the chloride conductance was low; valinomycin and an inwardly directed potassium gradient did not stimulated 36Cl uptake, anthracene-9-carboxylic acid did not inhibit 36Cl uptake, and valinomycin did not stimulated chloride-dependent 86Rb uptake. However, in the presence of 1 mM magnesium, opposite results were obtained; valinomycin and an inwardly directed potassium gradient stimulated 36Cl uptake, anthracene-9-carboxylic acid inhibited 36Cl uptake, and valinomycin stimulated chloride-dependent 86Rb uptake. Therefore, an electrically neutral K-Cl cotransport and magnesium-induced chloride conductance were found in renal cortial basolateral membrane vesicles prepared from the rabbit renal cortex

  20. Ionic conductivity in irradiated KCL; Conductiviad ionica de KCL irradiado

    Vignolo Rubio, J.

    1979-07-01

    The ionic conductivity of X and gamma irradiated KCL single crystals has been studied between room temperature and 600 degree centigree. the radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 degree centigree respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. However. It has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that, samples radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (Author)

  1. Ionic conductivity in irradiated KCL

    The ionic conductivity of X and gamma irradiated KCL single crystals has been studied between room temperature and 600 degree centigree. the radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 degree centigree respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. However. It has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that, samples radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (Author)

  2. Passive water and ion transport by cotransporters

    Loo, D D; Hirayama, B A; Meinild, A K;

    1999-01-01

    1. The rabbit Na+-glucose (SGLT1) and the human Na+-Cl--GABA (GAT1) cotransporters were expressed in Xenopus laevis oocytes, and passive Na+ and water transport were studied using electrical and optical techniques. Passive water permeabilities (Lp) of the cotransporters were determined from...... the low Ea for water transport is similar to that of water channels (aquaporins). 4. GAT1 also behaved as an SKF89976A-sensitive water channel. We did not observe passive Na+ transport through GAT1. 5. We conclude that passive water and Na+ transport through cotransporters depend on different mechanisms...... the Lp of control oocytes. Passive Na+ transport (Na+ leak) was obtained from the blocker-sensitive Na+ currents in the absence of substrates (glucose and GABA). 2. Passive Na+ and water transport through SGLT1 were blocked by phlorizin with the same sensitivity (inhibitory constant (Ki), 3-5 micro...

  3. Ischemia-induced stimulation of Na-K-Cl cotransport in cerebral microvascular endothelial cells involves AMP kinase.

    Wallace, Breanna K; Foroutan, Shahin; O'Donnell, Martha E

    2011-08-01

    Increased blood-brain barrier (BBB) Na-K-Cl cotransporter activity appears to contribute to cerebral edema formation during ischemic stroke. We have shown previously that inhibition of BBB Na-K-Cl cotransporter activity reduces edema and infarct in the rat middle cerebral artery occlusion (MCAO) model of ischemic stroke. We have also shown that the BBB cotransporter is stimulated by the ischemic factors hypoxia, aglycemia, and arginine vasopressin (AVP), although the mechanisms responsible are not well understood. AMP-activated protein kinase (AMPK), a key mediator of cell responses to stress, can be activated by a variety of stresses, including ischemia, hypoxia, and aglycemia. Previous studies have shown that the AMPK inhibitor Compound C significantly reduces infarct in mouse MCAO. The present study was conducted to evaluate the possibility that AMPK participates in ischemic factor-induced stimulation of the BBB Na-K-Cl cotransporter. Cerebral microvascular endothelial cells (CMEC) were assessed for Na-K-Cl cotransporter activity as bumetanide-sensitive (86)Rb influx. AMPK activity was assessed by Western blot analysis and immunofluorescence methods using antibodies that detect total versus phosphorylated (activated) AMPK. We found that hypoxia (7% and 2% O(2)), aglycemia, AVP, and oxygen-glucose deprivation (5- to 120-min exposures) increase activation of AMPK. We also found that Compound C inhibition of AMPK reduces hypoxia-, aglycemia-, and AVP-induced stimulation of CMEC Na-K-Cl cotransporter activity. Confocal immunofluorescence of perfusion-fixed rat brain slices revealed the presence of AMPK, both total and phosphorylated kinase, in BBB in situ of both control and ischemic brain. These findings suggest that ischemic factor stimulation of the BBB Na-K-Cl cotransporter involves activation of AMPK. PMID:21562306

  4. Exploring the intricate regulatory network controlling the thiazide-sensitive NaCl cotransporter (NCC)

    Dimke, Henrik

    2011-01-01

    for a WNK4 PHAII mutation to increase NCC phosphorylation and blood pressure in mice. The mouse protein 25α is a novel regulator of the SPAK/OSR1 kinase family, which greatly increases their activity. The phosphorylation status of NCC and the WNK is regulated by the serum- and glucocorticoid...... effect is dependent on the phosphorylation status of the cotransporter. γ-Adducin only binds the dephosphorylated cotransporter, suggesting that phosphorylation of NCC causes the dissociation of γ-adducin. Since γ-adducin is not a kinase, it is tempting to speculate that the protein exerts its function...

  5. Activation of ion transport systems during cell volume regulation

    This review discusses the activation of transport pathways during volume regulation, including their characteristics, the possible biochemical pathways that may mediate the activation of transport pathways, and the relations between volume regulation and transepithelial transport in renal cells. Many cells regulate their volume when exposed to an anisotonic medium. The changes in cell volume are caused by activation of ion transport pathways, plus the accompanying osmotically driven water movement such that cell volume returns toward normal levels. The swelling of hypertonically shrunken cells is termed regulatory volume increase (RVI) and involves an influx of NaCl into the cell via either activation of Na-Cl, Na-K-2Cl cotransport systems, or Na+-H+ and Cl--HCO3- exchangers. The reshrinking of hypotonically swollen cells is termed regulatory volume decrease (RVD) and involves an efflux of KCl and water from the cell by activation of either separate K+ and Cl- conductances, a K-Cl cotransport system, or parallel K+-H+ and Cl--HCO3- exchangers. The biochemical mechanisms involved in the activation of transport systems are largely unknown, however, the phosphoinositide pathway may be implicated in RVI; phorbol esters, cGMP, and Ca2+ affect the process of volume regulation. Renal tubular cells, as well as the blood cells that transverse the medulla, are subjected to increasing osmotic gradients from the corticomedullary junction to the papillary tip, as well as changing interstitial and tubule fluid osmolarity, depending on the diuretic state of the animal. Medullary cells from the loop of Henle and the papilla can volume regulate by activating Na-K-2Cl cotransport or Na+-H+ and Cl--HCO3- exchange systems

  6. Swelling-Activated Anion Channels Are Essential for Volume Regulation of Mouse Thymocytes

    Ravshan Z. Sabirov

    2011-12-01

    Full Text Available Channel-mediated trans-membrane chloride movement is a key process in the active cell volume regulation under osmotic stress in most cells. However, thymocytes were hypothesized to regulate their volume by activating a coupled K-Cl cotransport mechanism. Under the patch-clamp, we found that osmotic swelling activates two types of macroscopic anion conductance with different voltage-dependence and pharmacology. At the single-channel level, we identified two types of events: one corresponded to the maxi-anion channel, and the other one had characteristics of the volume-sensitive outwardly rectifying (VSOR chloride channel of intermediate conductance. A VSOR inhibitor, phloretin, significantly suppressed both macroscopic VSOR-type conductance and single-channel activity of intermediate amplitude. The maxi-anion channel activity was largely suppressed by Gd3+ ions but not by phloretin. Surprisingly, [(dihydroindenyloxy] alkanoic acid (DIOA, a known antagonist of K-Cl cotransporter, was found to significantly suppress the activity of the VSOR-type single-channel events with no effect on the maxi-anion channels at 10 μM. The regulatory volume decrease (RVD phase of cellular response to hypotonicity was mildly suppressed by Gd3+ ions and was completely abolished by phloretin suggesting a major impact of the VSOR chloride channel and modulatory role of the maxi-anion channel. The inhibitory effect of DIOA was also strong, and, most likely, it occurred via blocking the VSOR Cl− channels.

  7. Calculation of NaCl, KCl and LiCl Salts Activity Coefficients in Polyethylene Glycol (PEG4000)-Water System Using Modified PHSC Equation of State, Extended Debye-Hückel Model and Pitzer Model

    Marjani, Azam

    2016-07-01

    For biomolecules and cell particles purification and separation in biological engineering, besides the chromatography as mostly applied process, aqueous two-phase systems (ATPS) are of the most favorable separation processes that are worth to be investigated in thermodynamic theoretically. In recent years, thermodynamic calculation of ATPS properties has attracted much attention due to their great applications in chemical industries such as separation processes. These phase calculations of ATPS have inherent complexity due to the presence of ions and polymers in aqueous solution. In this work, for target ternary systems of polyethylene glycol (PEG4000)-salt-water, thermodynamic investigation for constituent systems with three salts (NaCl, KCl and LiCl) has been carried out as PEG is the most favorable polymer in ATPS. The modified perturbed hard sphere chain (PHSC) equation of state (EOS), extended Debye-Hückel and Pitzer models were employed for calculation of activity coefficients for the considered systems. Four additional statistical parameters were considered to ensure the consistency of correlations and introduced as objective functions in the particle swarm optimization algorithm. The results showed desirable agreement to the available experimental data, and the order of recommendation of studied models is PHSC EOS > extended Debye-Hückel > Pitzer. The concluding remark is that the all the employed models are reliable in such calculations and can be used for thermodynamic correlation/predictions; however, by using an ion-based parameter calculation method, the PHSC EOS reveals both reliability and universality of applications.

  8. Cotransport of water by Na¿-K¿-2Cl¿ cotransporters expressed in Xenopus oocytes

    Zeuthen, Thomas; Macaulay, Nanna

    2012-01-01

    The NKCC1 and NKCC2 isoforms of the mammalian Na¿–K¿–2Cl¿ cotransporter were expressed in Xenopus oocytes and the relation between external ion concentration and water fluxes determined.Water fluxes were determined from changes in the oocytes volume and ion fluxes from 86Rb+ uptake. Isotonic...... increases in external K¿ concentration elicited abrupt inward water fluxes in NKCC1; the K¿ dependence obeyed one-site kinetics with a K0.5 of 7.5 mM. The water fluxes were blocked by bumetanide, had steep temperature dependence and could proceed uphill against an osmotic gradient of 20 mosmol l¿¹. A...... comparison between ion and water fluxes indicates that 460 water molecules are cotransported for each turnover of the protein. In contrast, NKCC2 did not support water fluxes.Water transport in NKCC1 induced by increases in the external osmolarity had high activation energy and was blocked by bumetanide. The...

  9. Vasopressin alters the mechanism of apical Cl- entry from Na+:Cl- to Na+:K+:2Cl- cotransport in mouse medullary thick ascending limb

    Experiments were performed using in vitro perfused medullary thick ascending limbs of Henle (MTAL) and in suspensions of MTAL tubules isolated from mouse kidney to evaluate the effects of arginine vasopressin (AVP) on the K+ dependence of the apical, furosemide-sensitive Na+:Cl- cotransporter and on transport-related oxygen consumption (QO2). In isolated perfused MTAL segments, the rate of cell swelling induced by removing K+ from, and adding one mM ouabain to, the basolateral solution [ouabain(zero-K+)] provided an index to apical cotransporter activity and was used to evaluate the ionic requirements of the apical cotransporter in the presence and absence of AVP. In the absence of AVP cotransporter activity required Na+ and Cl-, but not K+, while the presence of AVP the apical cotransporter required all three ions. 86Rb+ uptake into MTAL tubules in suspension was significant only after exposure of tubules to AVP. Moreover, 22Na+ uptake was unaffected by extracellular K+ in the absence of AVP while after AVP exposure 22Na+ uptake was strictly K+-dependent. The AVP-induced coupling of K+ to the Na+:Cl- cotransporter resulted in a doubling in the rate of NaCl absorption without a parallel increase in the rate of cellular 22Na+ uptake or transport-related oxygen consumption. These results indicate that arginine vasopressin alters the mode of a loop diuretic-sensitive transporter from Na+:Cl- cotransport to Na+:K+:2Cl- cotransport in the mouse MTAL with the latter providing a distinct metabolic advantage for sodium transport. A model for AVP action on NaCl absorption by the MTAL is presented and the physiological significance of the coupling of K+ to the apical Na+:Cl- cotransporter in the MTAL and of the enhanced metabolic efficiency are discussed

  10. Isotonic transport by the Na+-glucose cotransporter SGLT1 from humans and rabbit

    Zeuthen, T; Meinild, A K; Loo, D D;

    2001-01-01

    water transport was divided about equally between cotransport, osmosis across the SGLT1 and osmosis across the native oocyte membrane. 6. Coexpression of AQP1 with the SGLT1 increased the water permeability more than 10-fold and steady state isotonic transport was achieved after less than 2 s of sugar......1. In order to study its role in steady state water transport, the Na+-glucose cotransporter (SGLT1) was expressed in Xenopus laevis oocytes; both the human and the rabbit clones were tested. The transport activity was monitored as a clamp current and the flux of water followed optically...... as the change in oocyte volume. 2. SGLT1 has two modes of water transport. First, it acts as a molecular water pump: for each 2 Na+ and 1 sugar molecule 264 water molecules were cotransported in the human SGLT1 (hSGLT1), 424 for the rabbit SGLT1 (rSGLT1). Second, it acts as a water channel. 3. The cotransport...

  11. Evidence for an apical Na-Cl cotransporter involved in ion uptake in a teleost fish

    Hiroi, J.; Yasumasu, S.; McCormick, S.D.; Hwang, P.-P.; Kaneko, T.

    2008-01-01

    Cation-chloride cotransporters, such as the Na+/K +/2Cl- cotransporter (NKCC) and Na+/Cl - cotransporter (NCC), are localized to the apical or basolateral plasma membranes of epithelial cells and are involved in active ion absorption or secretion. The objectives of this study were to clone and identify 'freshwater-type' and 'seawater-type' cation-chloride cotransporters of euryhaline Mozambique tilapia (Oreochromis mossambicus) and to determine their intracellular localization patterns within mitochondria-rich cells (MRCs). From tilapia gills, we cloned four full-length cDNAs homologous to human cation-chloride cotransporters and designated them as tilapia NKCC1a, NKCC1b, NKCC2 and NCC. Out of the four candidates, the mRNA encoding NKCC1a was highly expressed in the yolk-sac membrane and gills (sites of the MRC localization) of seawater-acclimatized fish, whereas the mRNA encoding NCC was exclusively expressed in the yolk-sac membrane and gills of freshwater-acclimatized fish. We then generated antibodies specific for tilapia NKCC1a and NCC and conducted whole-mount immunofluorescence staining for NKCC1a and NCC, together with Na+/K+-ATPase, cystic fibrosis transmembrane conductance regulator (CFTR) and Na+/H+ exchanger 3 (NHE3), on the yolk-sac membrane of tilapia embryos acclimatized to freshwater or seawater. The simultaneous quintuple-color immunofluorescence staining allowed us to classify MRCs clearly into four types: types I, II, III and IV. The NKCC1a immunoreactivity was localized to the basolateral membrane of seawater-specific type-IV MRCs, whereas the NCC immunoreactivity was restricted to the apical membrane of freshwater-specific type-II MRCs. Taking account of these data at the level of both mRNA and protein, we deduce that NKCC1a is the seawater-type cotransporter involved in ion secretion by type-IV MRCs and that NCC is the freshwater-type cotransporter involved in ion absorption by type-II MRCs. We propose a novel ion-uptake model by MRCs in

  12. The Human Sodium-Glucose Cotransporter (hSGLT1) Is a Disulfide-Bridged Homodimer with a Re-Entrant C-Terminal Loop

    Sasseville, Louis J.; Michael Morin; Coady, Michael J.; Rikard Blunck; Jean-Yves Lapointe

    2016-01-01

    Na-coupled cotransporters are proteins that use the trans-membrane electrochemical gradient of Na to activate the transport of a second solute. The sodium-glucose cotransporter 1 (SGLT1) constitutes a well-studied prototype of this transport mechanism but essential molecular characteristics, namely its quaternary structure and the exact arrangement of the C-terminal transmembrane segments, are still debated. After expression in Xenopus oocytes, human SGLT1 molecules (hSGLT1) were labelled on ...

  13. [Electrophysiology principles of Na(+)/HCO3(-) cotransporters].

    Chen, Li-Ming; Liu, Mei; Liu, Ying

    2016-06-25

    Ion channels and transporters represent two major types of pathways of transmembrane transport for ions. Distinct from ion channels which conduct passive ionic diffusion, ion transporters mediate active transport of ions. In the perspective of biochemistry, ion transporters are enzymes that catalyze the movement of ions across the plasma membrane. In the present review, we selected the Na(+)/HCO3(-) cotransporter (NBC) as an example to analyze the key biochemical and biophysical properties of ion transporters, including stoichiometry, turnover number and transport capacity. Moreover, we provided an analysis of the electrophysiological principles of NBC based on the laws of thermodynamics. Based on the thermodynamical analysis, we showed how the stoichiometry of an NBC determines the direction of its ion transport. Finally, we reviewed the methodology for experimental determination of the stoichiometry of NBC, as well as the physiological significance of the stoichiometry of NBCs in specific tissues. PMID:27350205

  14. γ-Adducin stimulates the thiazide-sensitive NaCl cotransporter

    Dimke, Henrik Anthony; San-Cristobal, Pedro; de Graaf, Mark;

    2011-01-01

    The thiazide-sensitive NaCl cotransporter (NCC) plays a key role in renal salt reabsorption and the determination of systemic BP, but the molecular mechanisms governing the regulation of NCC are not completely understood. Here, through pull-down experiments coupled to mass spectrometry, we found...... state, and consequently the activity, of the transporter. These data suggest that γ-adducin may influence BP homeostasis by modulating renal NaCl transport....

  15. The Na+/H+ exchanger NHE1, but not the Na+, HCO3- cotransporter NBCn1, regulates motility of MCF7 breast cancer cells expressing constitutively active ErbB2

    Lauritzen, Gitte; Stock, Christian-Martin; Lemaire, Justine; Lund, Stine F.; Jensen, Mie Frid; Damsgaard, Britt; Petersen, Katrine Seide; Wiwel, Maria; Rønnov-Jessen, Lone; Schwab, Albrecht; Pedersen, Stine Helene Falsig

    2012-01-01

    We and others have shown central roles of the Na(+)/H(+) exchanger NHE1 in cell motility. The aim of this study was to determine the roles of NHE1 and of the Na(+), HCO(3)(-) cotransporter NBCn1 in motility of serum-starved MCF-7 breast cancer cells expressing constitutively active ErbB2 (¿NErbB2...... diameter of which was increased by ¿NErbB2. Adhesion and migration on collagen-I were augmented by ¿NErbB2, unaffected by the NBC inhibitor S0859, and further stimulated by EIPA in a manner potentiated by PI3K-Akt-inhibition. These findings demonstrate that NHE1 inhibition can enhance cancer cell motility...

  16. Molecular Physiology of the Thiazide-sensitive Sodium Chloride Cotransporter

    Ko, Benjamin; Hoover, Robert S.

    2010-01-01

    Purpose of review This review summarizes recent advances in the understanding of the molecular physiology and regulation of the thiazide-sensitive cotransporter (NCC). Recent findings Mutations of With-No-Lysine (WNK) Kinases 1 and 4 result in hyperactivity of NCC and FHHt (Familial Hyperkalemic Hypertension), a genetic syndrome of hypertension. Recent studies have shown that WNK1 and WNK4 activate the STE20 family protein kinases SPAK and OSR1, resulting in phosphorylation and activation of NCC. Additionally, a mouse knock-in model for a WNK4 FHHt mutant demonstrated increased SPAK/OSR1 and NCC phosphorylation. It is unclear how these studies fit with the data indicating that WNK4 inhibits NCC and the FHHt mutations of WNK4 are loss-of-function mutations. Another WNK kinase, WNK3, regulates NCC, activating NCC and antagonizing WNK4's effect. Recent studies examining the hormonal regulation of NCC have implicated angiotensin II and aldosterone in regulation of the WNK4-SPAK-NCC pathway. Angiotensin II may also play a role in pressure natriuresis via actions on NCC. Summary NCC is subject to a complex regulatory network of kinases which appear sensitive to alterations of the hormonal and physiologic milieu. PMID:19636250

  17. Vasopressin alters the mechanism of apical Cl- entry from Na+:Cl- to Na+:K+:2Cl- cotransport in mouse medullary thick ascending limb

    Sun, A.; Grossman, E.B.; Lombardi, M.; Hebert, S.C. (Brigham and Women' s Hospital, Boston, MA (USA))

    1991-02-01

    Experiments were performed using in vitro perfused medullary thick ascending limbs of Henle (MTAL) and in suspensions of MTAL tubules isolated from mouse kidney to evaluate the effects of arginine vasopressin (AVP) on the K+ dependence of the apical, furosemide-sensitive Na{sup +}:Cl{sup {minus}} cotransporter and on transport-related oxygen consumption (QO{sub 2}). In isolated perfused MTAL segments, the rate of cell swelling induced by removing K+ from, and adding one mM ouabain to, the basolateral solution (ouabain(zero-K+)) provided an index to apical cotransporter activity and was used to evaluate the ionic requirements of the apical cotransporter in the presence and absence of AVP. In the absence of AVP cotransporter activity required Na{sup +} and Cl{sup {minus}}, but not K{sup +}, while the presence of AVP the apical cotransporter required all three ions. {sup 86}Rb{sup +} uptake into MTAL tubules in suspension was significant only after exposure of tubules to AVP. Moreover, {sup 22}Na{sup +} uptake was unaffected by extracellular K+ in the absence of AVP while after AVP exposure {sup 22}Na{sup +} uptake was strictly K{sup +}-dependent. The AVP-induced coupling of K{sup +} to the Na{sup +}:Cl{sup {minus}} cotransporter resulted in a doubling in the rate of NaCl absorption without a parallel increase in the rate of cellular {sup 22}Na{sup +} uptake or transport-related oxygen consumption. These results indicate that arginine vasopressin alters the mode of a loop diuretic-sensitive transporter from Na{sup +}:Cl{sup {minus}} cotransport to Na{sup +}:K{sup +}:2Cl{sup {minus}} cotransport in the mouse MTAL with the latter providing a distinct metabolic advantage for sodium transport. A model for AVP action on NaCl absorption by the MTAL is presented and the physiological significance of the coupling of K{sup +} to the apical Na{sup +}:Cl{sup {minus}} cotransporter in the MTAL and of the enhanced metabolic efficiency are discussed.

  18. Thermodynamics of the NaCl–KCl system

    Highlights: • The complementary methods of DSC, DTA, DROP and XRD analyses were used. • The heat capacity of solid phase of the NaCl–KCl mixtures was measured. • The heat capacity of liquid phase of the 50NaCl–50KCl mixture was obtained. • The enthalpy of fusion and solid solution formation were determined. • The thermodynamic functions of the 50NaCl–50KCl mixture were calculated. - Abstract: The heat capacity of the solid phase of the NaCl–KCl mixtures was measured by the differential scanning calorimetry. These results and X-ray diffraction data were used for the explanation of the solid solution formation. The heat capacity of the liquid phase of the eutectic 50NaCl–50KCl mixture has been obtained in a closed glass container. The enthalpy increment (H°T − H°298.15) and the fusion enthalpy of the 50NaCl–50KCl mixture have been measured by a drop calorimeter. The joint analysis of these values with the heat capacity data allowed the calculation of the enthalpy of the solid solution. As the final result, the thermodynamic functions of the eutectic 50NaCl–50KCl mixture have been obtained

  19. Regulation of the human Na+-dependent glucose cotransporter hSGLT2

    Ghezzi, Chiara; Wright, Ernest M.

    2012-01-01

    The human Na+-glucose cotransporter SGLT2 is expressed mainly in the kidney proximal convoluted tubule where it is considered to be responsible for the bulk of glucose reabsorption. Phosphorylation profiling has revealed that SGLT2 exists in a phosphorylated state in the rat renal proximal tubule cortex, so we decided to investigate the regulation of human SGLT2 (hSGLT2) by protein kinases. hSGLT2 was expressed in human embryonic kidney (HEK) 293T cells, and the activity of the protein was me...

  20. Expression of apical Na(+)-L-glutamine co-transport activity, B(0)-system neutral amino acid co-transporter (B(0)AT1) and angiotensin-converting enzyme 2 along the jejunal crypt-villus axis in young pigs fed a liquid formula

    Gut apical amino acid (AA) transport activity is high at birth and during suckling, thus being essential to maintain luminal nutrient-dependent mucosal growth through providing AA as essential metabolic fuel, substrates and nutrient stimuli for cellular growth. Because system-B(0) Na(+)-neutral AA c...

  1. Na+/HCO3- Cotransport in Normal and Cystic Fibrosis Intestine

    Seidler U

    2001-07-01

    Full Text Available In a search for the HCO(3(- supply mechanisms to the enterocyte we cloned and sequenced an intestinal subtype of the Na(+HCO(3(- cotransporter isoform I (dNBC1, which turned out to be identical to the pancreatic NBC1 subtype (pNBC1. Within the intestine, we found particularly high NBC1 expression levels in the duodenum and proximal colon. Experiments with stripped rabbit duodenum in Ussing-chambers revealed that Na(+HCO(3(- cotransport (NBC and CO(2 hydration/Na(+/H(+ exchange were equally important duodenal HCO(3(- supply pathways and were both upregulated during cAMP-mediated secretion. In the proximal colon, however, HCO(3(- secretion was low but NBC1 expression even higher than in the duodenum. Ussing-chamber experiments with an NBC-specific inhibitor revealed that NBC, coupled to basolateral Cl(-/HCO(3(- exchange, was an important alternative Cl(- supply pathway to Na(+K(+2Cl(- cotransport (NKCC during cAMP-stimulated colonic Cl(- secretion. To investigate the functional integrity of anion uptake pathways in the absence of cystic fibrosis transmembrane conductance regulator (CFTR, we fluorometrically assessed NBC and NKCC transport rates and cell volume before and during forskolin-stimulation in isolated colonic crypts from normal and CFTR (-/- mice. Although forskolin stimulation decreased cell volume only in normal, not in CFTR (-/- crypts, it activated NBC and NKCC to a similar degree in both normal and CFTR (-/- crypts. We conclude that, depending on the intestinal segment, NBC1 plays an important role in basolateral HCO(3(- or Cl(- uptake. Expression and activation by cAMP is preserved in CFTR (-/- intestine.

  2. Characterization of Fe/KClO4 heat powders and pellets.

    Reinhardt, Frederick William; Guidotti, Ronald Armand; Odinek, Judy Gail

    2005-04-01

    Pellets of Fe/KClO{sub 4} mixtures are used as a heat source for thermally activated ('thermal') batteries. They provide the energy necessary for melting the electrolyte and bringing the battery stack to operating temperature. The effects of morphology of the Fe and the heat-pellet density and composition on both the physical properties (flowability, pelletization, and pellet strength) and the pyrotechnic performance (burn rate and ignition sensitivity) were examined using several commercial sources of Fe.

  3. Electroplating of erbium on steel surface in ErCl3 doped LiCl-KCl

    The electroplating of Er metal on the reduced activation ferritic martensitic steel, JLF-1 (Fe-9Cr-2W-0.1C), in a molten salt was studied. The specimen was immersed in the molten ErCl3 doped LiCl-KCl electrolyte. The electroplating was carried out by a constant potential electrolysis method and a pulsed current electrolysis method. It was found that the Er metal was deposited on the specimen surface due to the electrochemical reaction. (author)

  4. Optical properties of KCl:Sn2+ phosphors synthesized from aqueous KCl/SnCl2 solutions

    Nara, Jun-ichi; Adachi, Sadao

    2011-12-01

    KCl:Sn2+ phosphors were synthesized from aqueous KCl/SnCl2 solutions. Solvents with a molar ratio of KCl : SnCl2 = 1 : M (M = 0 - 5) were dissolved in de-ionized water. The optical properties of the synthesized phosphors were investigated by photoluminescence (PL) analysis, PL excitation spectroscopy (PLE), and PL lifetime measurements. KCl:Sn2+ phosphor synthesized with M = 0.1 exhibited the strongest PL emission in the green (AT band) and red spectral regions (R band). The phosphors synthesized with M ≥ 1 were composites of various potassium chlorostannates and emitted light in the red spectral region (R band). Annealing the M = 0.1 phosphor in dry N2 resulted in a PL spectrum that was the same as those usually observed in melt-grown KCl:Sn2+ phosphors (i.e., exhibiting only the AT emission band). Annealing also led to a change in the PL decay characteristic from a double exponential curve to a single exponential curve. The AT and R emission bands had nearly the same PLE spectra and were related to the deexcitation of the Sn2+ (5s5p) ions in KCl.

  5. Electrochemical behaviour of plutonium ion in LiCl-KCl eutectic melts

    This work presents a study on the electrochemical properties of PuCl3 in a molten LiCl-KCl eutectic, at a temperature range of 733-833 K. Transient electrochemical techniques, such as cyclic voltammetry and chrono-potentiometry, on inert metallic tungsten and molybdenum working electrodes have been used in order to investigate the reduction mechanism and transport parameters. The results show that Pu3+ is reduced to Pu metal by a single step mechanism and that the diffusion coefficient of Pu3+ ion is DPu3+ ∼2.10-5 cm2/s at 733 K. In addition the standard potential (-2796 V at 733 and vs. Cl2/Cl- reference electrode) and free enthalpy of formation for the Pu(III)/Pu(0) system have been measured and compared to thermodynamic data in order to estimate the activity coefficient of Pu3+ in the molten LiCl-KCl eutectic. (author)

  6. Electrochemical study of uranium cations in LiCl-KCl melt using a rotating disk electrode

    Bae, Sang-Eun; Kim, Dae-Hyun; Kim, Jong-Yoon; Park, Tae-Hong; Cho, Young Hwan; Yeon, Jei-Won; Song, Kyuseok [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute,989-111 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

    2013-07-01

    A rotating disk electrode (RDE) measurement technique was employed to investigate the electrochemical REDOX reactions of actinide (An) and lanthanide (Ln) ions in LiCl-KCl molten salt. By using RDE, it is possible to access more exact values of the diffusion coefficient, Tafel slope, and exchange current density. In this work, we constructed RDE setup and electrodes for RDE measurements in high temperature molten salt and measured the electrochemical parameters of the An and Ln ions. The RDE setup is composed of a Pine model MSRX rotator equipped with a rod type of W electrode. The active electrode area was confined to the planar part of the W rod by making meniscus at the LiCl-KCl melt surface.

  7. Nanomaterials-Based Approaches for the Modulation of Sodium Bicarbonate Cotransporters

    Jeong Hee Hong

    2015-01-01

    Full Text Available HCO3- and fluid secretion are major functions of all epithelia, and alterations in HCO3- secretion by sodium bicarbonate cotransporters are associated with many epithelial diseases, such as renal, ocular, and dental abnormalities. Electrolyte and fluid exits are synergistically mediated by the intracellular second messengers, cAMP and Ca2+, and this raises the possibility that ion transporters are involved in simple secretion and more complicated forms of regulation. Evidence indicates that HCO3- transport is regulated by the assemblage of Na+-HCO3- cotransporters (NBCs into complexes by multiple regulatory factors. Recently the specific regulatory functions of factors that interact with NBCe1, especially NBCe1-B, have been elucidated. In this review, I focus on the structural characteristics of electrogenic NBCe1, pathophysiology of NBCe1, and molecular mechanisms responsible for transporter regulation. Moreover I propose the possibility to apply nanomaterials combined with regulatory factors for modulating the activity of NBC transporters as a potential development of therapeutic drug.

  8. Molecular and evolutionary insights into the structural organization of cation chloride cotransporters

    Anna-Maria Hartmann

    2015-01-01

    Full Text Available Cation chloride cotransporters (CCC play an essential role for neuronal chloride homeostasis. KCC2 is the principal Cl--extruder, whereas NKCC1 is the major Cl--uptake mechanism in many neurons. As a consequence, the action of the inhibitory neurotransmitters GABA and glycine strongly depend on the activity of these two transporters. Knowledge of the mechanisms involved in ion transport and regulation is thus of great importance to better understand normal and disturbed brain function. Although no overall 3-dimensional crystal structures are yet available, recent molecular and phylogenetic studies and modeling have provided new and exciting insights into structure-function relationships of cation chloride cotransporters. Here, we will summarize our current knowledge of the gross structural organization of the proteins, their functional domains, ion binding and translocation sites, and the established role of individual amino acids. A major focus will be laid on the delineation of shared and distinct organizational principles between KCC2 and NKCC1. Exploiting the richness of recently generated genome data across the tree of life, we will also explore the molecular evolution of these features.

  9. The Na+/glucose cotransporters: from genes to therapy

    R. Sabino-Silva; R.C. Mori; A. David-Silva; M.M. Okamoto; H.S. Freitas; U.F. Machado

    2010-01-01

    Glucose enters eukaryotic cells via two types of membrane-associated carrier proteins, the Na+/glucose cotransporters (SGLT) and the facilitative glucose transporters (GLUT). The SGLT family consists of six members. Among them, the SGLT1 and SGLT2 proteins, encoded by the solute carrier genes SLC5A1 and SLC5A2, respectively, are believed to be the most important ones and have been extensively explored in studies focusing on glucose fluxes under both physiological and pathological conditions. ...

  10. Phase relations in the hydrous CMAS pyrolite in presence of KCl at 2 GPa

    Safonov, O.

    2012-04-01

    In the upper mantle, chlorides are constituents of concentrated aqueous solutions (brines), as well as chloride-carbonate and carbonatite melts. Mineral assemblages coming from diverse depth levels show that mobile (K, Na)Cl-bearing fluids are able to provoke intensive metasomatism of the peridotitic mantle accompanied by melting. Scarce experimental studies on influence of brines on mineral equilibria in the peridotitic mantle (Stalder et al., 2008; Chu et al., 2011) indicate that influence of chlorides on water activity in a fluid equilibrated with forsterite enstatite at pressures above 2 GPa is very similar to their effect at lower "crustal" pressures (e.g. Aranovich, Newton, 1997): decrease of the H2O activity with an increase of the salt content results in an increase of the melting temperature of silicates. Nevertheless, these experiments were performed in the Al-free systems. Presence of Al would provoke an active interaction of alkali chlorides, namely KCl, with silicates with formation of new K-Al-bearing phases, such as phlogopite (in presence of H2O), which would influence on the melting of complex assemblages. In order to investigate an effect of KCl on phase relations in the Al2O3, CaO, Na2O-rich hydrous peridotite and on stability of garnet, pyroxenes, and amphiboles, in particular, experiments on interaction of the model CMAS pyrolite Fo57En17Prp14Di12 (+0.3 wt. % of Na2O) with the H2O-KCl fluid were performed at 2 GPa in the temperature interval 900-1200. Mixtures of synthetic forsterite, diopside, enstatite and pyrope in the above weight ratio were mixed with 14 wt. % of Mg(OH)2 corresponding to 4.4 wt. % of H2O in the system. 2.4, 3.7, 5 and 10 wt. % of KCl were added to silicate-H2O mixture. Experiments were performed using a piston-cylinder apparatus with ½-inch talc high-pressure cells calibrated via brucite = periclase + H2O and albite = jadeite + quartz equilibria curves. Temperature was controlled with accuracy ?1 with the W95Re5/W80Re20

  11. Study of effect of quenching and deformation on KCl: Gd3+ crystals by using conductivity measurements

    G Saibabu; A Ramachandra Reddy; D Srikanth

    2004-10-01

    The study of ionic conductivity vs reciprocal temperature of pure KCl and KCl crystal doped with 0.1, 0.3 and 0.5 mole% gadolinium has been carried out in as grown, quenched from elevated temperatures (100, 350 and 500°C) and annealed at various timings i.e. 2–3 h and deformed by different percentages. The plots exhibit three well-known regions, II, III and IV (extrinsic regions). The intrinsic region I was not observed in the plots as the conductivity measurements were taken up to 575°C. From the analysis of these plots, activation energies for the migration of cation vacancy and the association of gadolinium ion with cation vacancy in the lattice of KCl crystals are calculated. These values are compared with previously reported values. Further, an attempt is made to explain the existence of oxidation state of gadolinium ion in + 3 state rather than in + 2 state as reported earlier. The variation in conductivity with effect of concentration of impurity ion, quenching and annealing and deformation with various percentages are explained on the basis of formation of impurity vacancy dipoles, vacancy – vacancy pairs (which appear in the form of precipitation), storage of cation vacancies in the form of defects, introduction of fresh dislocations, etc.

  12. Oscillatory rule in the energy spectrum of traps in KCl and NaI crystals

    Gumenyuk, A F; Stanovyi, O P; Pashchenko, V G; Tomylko, S V

    2010-01-01

    The thermoluminescence (TL) method is used for the investigation of the energy spectrum of traps in KCl and NaI crystals in the temperature range 80-500 K. It is shown that the thermal activation energies of traps in KCl and NaI form one oscillatory series E=hwn with vibrational quantum energies of 0.121 eV in KCl and 0.061 eV in NaI. In this case, the quantum number n assumes half-integer and integer values. Based on the generalized data on the investigated alkali-halide crystals (AHC), we confirmed the earlier proposed model of TL in AHCs. It is assumed that, in addition to the nonradiative H-F recombination, there exists the two-stage recombination of H-centers at anion vacancies resulting in the radiative recombination of a hole at an F-center. The energy of a quantum in the oscillatory rule corresponds to a local vibrational mode of an X2 halide molecule.

  13. KCl Crystal Growth and High Energy X Ray Expose of Properties

    X ray irradiates material for dose distribution confirmation through material color variation to evaluate about possibility. That is rare earth material to pure KCl and KCl impurity Eu adding 0.5 mol% by Czochralski method each single crystal grow and observed color variation of KCl X ray irradiation use of linear accelerator. High energy X ray irradiation KCl:Eu show the blue fluorescence with purple color that pure KCl single crystal can confirm by show was not observed, but was colored violet. Colors variation of KCl founds stable color center from radiation and this color variation will be used usefully to X ray measurement material and phantom.

  14. Fluorescence studies of ligand-induced conformational changes of the Na(+)/glucose cotransporter

    Meinild, Anne-Kristine; Hirayama, Bruce A; Wright, Ernest M;

    2002-01-01

    Conformational changes in the human Na(+)/glucose cotransporter (hSGLT1) were examined using hSGLT1 Q457C expressed in Xenopus laevis oocytes and tagged with tetramethylrhodamine-6-maleimide (TMR6M). Na(+)/glucose cotransport is abolished in the TMR6M-labeled mutant, but the protein binds Na(+) and...

  15. Entrained Flow Reactor Study of KCl Capture by Solid Additives

    Wang, Guoliang; Jensen, Peter Arendt; Wu, Hao;

    An option for abating deposition and corrosion caused byalkali species during biomass combustion, is the introduction of additivesinto boilers for transforming harmful gaseous alkali compounds (e.g. KCl,KOH) into less corrosive ash species with a higher melting point. Kaolin andcoal fly ash have...

  16. ESR of an O3- centre in KCl

    By means of ESR an ozonide molecular O3- ion was detected in x-irradiated KCl. The principal values of the G-tensor (2.0032, 2.0182, 2.0118) are in excellent agreement with the values found in other host lattices and with CNDO calculations performed earlier. All measurements were carried out at liquid-helium temperatures. (author)

  17. Water transport between CNS compartments: contributions of aquaporins and cotransporters

    MacAulay, N; Zeuthen, T

    2010-01-01

    hydrocephalus. The molecular pathways by which water molecules cross the cell membranes of the brain are not well-understood, although the discovery of aquaporin 4 (AQP4) in the brain improved our understanding of some of these transport processes, particularly under pathological conditions. In the present...... review we introduce another family of transport proteins as water transporters, namely the cotransporters and the glucose uniport GLUT1. In direct contrast to the aquaporins, these proteins have an inherent ability to transport water against an osmotic gradient. Some of them may also function as water...

  18. K+-Cl− cotransporter-2 KCC2 in chicken cardiomyocytes

    Antrobus, Shane P.; Lytle, Christian; Payne, John A.

    2012-01-01

    Using antibodies prepared against a unique region (exon 22–24) of rat K+-Cl− cotransporter-2 (KCC2), we confirmed that the ∼140-kDa KCC2 protein is exclusively expressed in rat brain, but in chicken, we observed strong reactivity not only with the ∼140-kDa KCC2 protein in brain but also a slightly larger ∼145-kDa protein in heart. In silico analysis showed that while exon 22 of KCC2 is unique to this isoform in therian mammals, it is retained in KCC2's closest paralog, KCC4, of lower vertebra...

  19. Mutations in the gene of human type IIb sodium-phosphate cotransporter SLC34A2

    Kiyamova R. G.

    2010-02-01

    Full Text Available Type IIb sodium-phosphate cotransporter (NaPi2b provides phosphate intake in the cells of some epithelial tissues, osteoblasts and odontoblasts. Abnormal expression of NaPi2b has been detected in some types of epithelial tumors. An alteration in NaPi2b activity, caused by mutations in transporter gene SLC34A2, has been recently revealed in patients with pulmonary alveolar microlithiasis, an autosomal recessively inherited disease, characterized by deposition of calcium-phosphate precipitates in the lungs. In the present study we have combined the information about all mutations found to date in the coding sequence of SLC34A2 and its transcript, compiled their map, and analysed their relevance to the function of NaPi2b.

  20. Characterization of Niobium Platings Obtained from NaCl-KCl Melts

    Gillesberg, Bo; Barner, Jens H. Von; Bjerrum, Niels

    1998-01-01

    oxidation of metallic niobium with NiCl2. The initial valency of niobium was found to 3 when a NaCl-KCl melt was applied as solvent. The deposits were characterised by X-ray analy-sis and Scanning Electron Microscopy (SEM) combined with EDX analysis. From both NaCl-KCl and LiCl-KCl melts dense and coherent...

  1. Cotransport of water by the Na+-K+-2Cl(-) cotransporter NKCC1 in mammalian epithelial cells

    Hamann, Steffen; Herrera-Perez, José J; Zeuthen, Thomas;

    2010-01-01

    Water transport by the Na+-K+-2Cl(-) cotransporter (NKCC1) was studied in confluent cultures of pigmented epithelial (PE) cells from the ciliary body of the fetal human eye. Interdependence among water, Na+ and Cl(-) fluxes mediated by NKCC1 was inferred from changes in cell water volume, monitored...... by intracellular self-quenching of the fluorescent dye calcein. Isosmotic removal of external Cl(-) or Na+ caused a rapid efflux of water from the cells, which was inhibited by bumetanide (10 µm). When returned to the control solution there was a rapid water influx that required the simultaneous...

  2. Studies on multiphased mixed crystals grown from NaBr and KCl

    Padma, C.M. [Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, Tamilnadu (India); Mahadevan, C.K. [Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, Tamilnadu (India)], E-mail: mahadevan58@yahoo.co.in

    2008-05-01

    We have grown multiphased binary and ternary mixed crystals by the melt method using the miscible alkali halides, viz. NaBr and KCl and physically characterized. Thermal parameters like Debye-Waller factor, Debye temperature, Debye frequency and mean square amplitude of vibration were determined using the X-ray powder diffraction intensity data. DC and AC electrical measurements were carried out by using the parallel plate capacitor method at various temperatures. Activation energies (DC and AC), mean jump frequency, compressibility and mean sound velocity were also determined. The results obtained are reported here.

  3. Electroreduction of Ho3+ on Nickel Cathode in Molten KCl-HoCl3

    2000-01-01

    The cyclic voltammetry, open current potential-time curve after potentiostatic electrolysis, the current-time curve at potential step, XRD, EDAX and EPMA were used to study the electrode process of Ho3+ reduction on nickel electrode in molten KCl-HoCl3 and the phases of surface alloy layer. The Ho-Ni alloys were deposited when Ho3+ was reduced on the nickel electrode. The free energies of formation for the intermetallic compounds between Ho and Ni, the diffusion coefficients and diffusion activation energy of Ho atom in the alloy phase were determined.

  4. Acidity constants in different media (I=0 and I=0.1 M KCl) from the uncertainty perspective.

    Koort, Eve; Gans, Peter; Herodes, Koit; Pihl, Viljar; Leito, Ivo

    2006-07-01

    Procedures for estimating the measurement uncertainty for the acidity constant Ka (or the pKa value) in different media (I=0 and I=0.1 mol L(-1) KCl), as determined by potentiometric titration, are presented. The uncertainty budgets (the relative contributions of the different input quantities to the uncertainty in the result) of the pKa (I=0) and pKa (I=0.1 mol L(-1) KCl) values are compared. Unlike the values themselves, the uncertainties and uncertainty budgets of the values are comparable. The uncertainty estimation procedures are based on mathematical models of pKa measurement and involve the identification and quantification of individual uncertainty sources according to the ISO GUM approach. The mathematical model involves 52 and 48 input parameters for pKa (I=0) and pKa (I=0.1 mol L(-1) KCl), respectively. The relative importance of each source of uncertainty is discussed. In both cases, the main contributors to the uncertainty budget are the uncertainty components due to the hydrogen ion concentration/activity measurement, which provide 63.7% (for pKa (I=0)) and 89.3% (for pKa (I=0.1 mol L(-1) KCl)) of the uncertainty. The remaining uncertainty contributions arise mostly from the limited purity of the acid. From this work, it is clear that the uncertainties of the pKa (I=0.1 mol L(-1) KCl) values tend to be lower than those of the pKa (I=0) values. The main reasons for this are that: (1) the uncertainty due to the residual liquid junction potential is nominally absent in the case of pKa (I=0.1 mol L(-1) KCl) due to the similarly high concentrations of background electrolyte in the calibration solutions and measured solution; (2) the electrode system is more stable in solutions containing the 0.1 mol L(-1) KCl background electrolyte and so the readings obtained in these solutions are more stable. PMID:16791552

  5. Thermal Properties of LiCl-KCl Molten Salt for Nuclear Waste Separation

    Sridharan, Kumar [Univ. of Wisconsin, Madison, WI (United States); Allen, Todd [Univ. of Wisconsin, Madison, WI (United States); Anderson, Mark [Univ. of Wisconsin, Madison, WI (United States); Simpson, Mike [Idaho National Lab., (United States)

    2012-11-30

    This project addresses both practical and fundamental scientific issues of direct relevance to operational challenges of the molten LiCl-KCl salt pyrochemical process, while providing avenues for improvements in the process. In order to understand the effects of the continually changing composition of the molten salt bath during the process, the project team will systematically vary the concentrations of rare earth surrogate elements, lanthanum, cerium, praseodymium, and neodymium, which will be added to the molten LiCl-KCl salt. They will also perform a limited number of focused experiments by the dissolution of depleted uranium. All experiments will be performed at 500 deg C. The project consists of the following tasks. Researchers will measure density of the molten salts using an instrument specifically designed for this purpose, and will determine the melting points with a differential scanning calorimeter. Knowledge of these properties is essential for salt mass accounting and taking the necessary steps to prevent melt freezing. The team will use cyclic voltammetry studies to determine redox potentials of the rare earth cations, as well as their diffusion coefficients and activities in the molten LiCl-KCl salt. In addition, the team will perform anodic stripping voltammetry to determine the concentration of the rare earth elements and their solubilities, and to develop the scientific basis for an on-line diagnostic system for in situ monitoring of the cation species concentration (rare earths in this case). Solubility and activity of the cation species are critically important for the prediction of the salt's useful lifetime and disposal.

  6. Protein induced morphological transitions in KCl crystal growth

    Szabó, B; Szabo, Balint; Vicsek, Tamas

    2003-01-01

    We investigated the formation of KCl crystals on glass surface by phase contrast, fluorescent, and atomic force microscopy on the micrometer scale, and observed interesting morphological transitions as a function of the experimental conditions. The presence of proteins in the solution from which the salt crystals grow during the drying up leads to complex microscopic patterns of crystals some of which are analogous to those commonly observed on the macroscopic scale. We tested the effect of tubulin, FITC-labeled albumin and IgG on the morphology of crystals grown either slowly or fast. A rich variety of protein specific and concentration dependent morphologies was found and described by a morphological diagram. We give a phenomenological interpretation, which can explain the growth of complex patterns. Fluorescent images prove that a protein layer covers the surface of the KCl structures. We propose that this layer reduces the anisotropy of the effective surface tension during growth. The tip splitting fracta...

  7. Electrochemistry of thorium in LiCl-KCl eutectic melts

    Cassayre, Laurent; Serp, Jérôme; Soucek, Pavel; Malmbeck, Rikard; Rebizant, Jean; Glatz, Jean-Paul

    2007-01-01

    This work presents a study of the electrochemical properties of Th chloride ions dissolved in a molten LiCl-KCl eutectic, in a temperature range of 693-823 K. Transient electrochemical techniques such as cyclic voltammetry and chronopotentiommetry have been used in order to investigate the reduction mechanism on a tungsten electrode and the diffusion coefficient of dissolved Th ions. All techniques showed that only one valence state was stable in the melt. The reduction into Th metal was foun...

  8. Entrained Flow Reactor Study of KCl Capture by Solid Additives

    Wang, Guoliang; Jensen, Peter Arendt; Wu, Hao; Jappe Frandsen, Flemming; Bøjer, M.; Glarborg, Peter

    2016-01-01

    An option for abating deposition and corrosion caused byalkali species during biomass combustion, is the introduction of additivesinto boilers for transforming harmful gaseous alkali compounds (e.g. KCl,KOH) into less corrosive ash species with a higher melting point. Kaolin andcoal fly ash have been proved to be very promising additives and havereceived extensive studies during the past decades. However, mostprevious studies were carried out in fixed-bed reactors where the reaction condition...

  9. Water transport by the Na+/glucose cotransporter under isotonic conditions

    Zeuthen, T; Meinild, A K; Klaerke, D A;

    1997-01-01

    Solute cotransport in the Na+/glucose cotransporter is directly coupled to significant water fluxes. The water fluxes are energized by the downhill fluxes of the other substrates by a mechanism within the protein itself. In the present paper we investigate the Na+/glucose cotransporter expressed ...... of water molecules and the number of Na+ ions transported, equivalent to 390 water molecules per glucose molecule. Unstirred layer effects are ruled out on the basis of experiments on native oocytes incubated with the ionophores gramicidin D or nystatin....

  10. Further studies on the partial double Donnan. Is isosmotic KCl solution isotonic with cells of respiratory trees of the holothurian Isostichopus badionotus Selenka?

    Herrera; Herrera; López

    2000-05-01

    As potassium, chloride and water traverse cell membranes, the cells of stenohaline marine invertebrates should swell if exposed to sea water mixed with an isosmotic KCl solution as they do when exposed to sea water diluted with water. To test this hypothesis respiratory tree fragments of the holothurian Isostichopus badionotus were exposed to five isosmotic media prepared by mixing artificial sodium sea water with isosmotic (611 mmol/l) KCl solution to obtain 100, 83, 71, 60 and 50% sea water, with and without 2 mmol/l ouabain. For comparison, respiratory tree fragments were incubated in sea water diluted to the same concentrations with distilled water, with and without ouabain. Cell water contents and potassium and sodium concentrations were unaffected by KCl-dilution or ouabain in isosmotic KCl-sea water mixtures. In tissues exposed to H(2)O-diluted sea water, cell water increased osmometrically and potassium, sodium and chloride concentrations decreased with dilution; ouabain caused a decrease in potasium and an increase in sodium but no effect on chloride concentrations. The isotonicity of the isosmotic KCl solution cannot be adscribed to impermeability of the cell membrane to KCl as both ions easily traverse the cell membrane. Rather, operationally immobilized extracellular sodium ions, which electrostatically hold back anions and consequently water, together with the lack of a cellward electrochemical gradient for potassium, resulting from membrane depolarization caused by high external potassium concentration, would explain the isotonicity of isosmotic KCl solution. The high external potassium concentration also antagonizes the inhibitory effect of ouabain on the Na(+)/K(+) ATPase responsible for sodium and potassium active transport. PMID:10742500

  11. Potassium-chloride cotransporter 3 interacts with Vav2 to synchronize the cell volume decrease response with cell protrusion dynamics.

    Adèle Salin-Cantegrel

    Full Text Available Loss-of-function of the potassium-chloride cotransporter 3 (KCC3 causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC, a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. Conversely, KCC3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. We identified a highly conserved proline-rich sequence within the C-terminus of the cotransporter which when mutated leads to loss of the KCC3-dependent regulatory volume decrease (RVD response in Xenopus Laevis oocytes. Using SH3 domain arrays, we found that this poly-proline motif is a binding site for SH3-domain containing proteins in vitro. This approach identified the guanine nucleotide exchange factor (GEF Vav2 as a candidate partner for KCC3. KCC3/Vav2 physical interaction was confirmed using GST-pull down assays and immuno-based experiments. In cultured cervical cancer cells, KCC3 co-localized with the active form of Vav2 in swelling-induced actin-rich protruding sites and within lamellipodia of spreading and migrating cells. These data provide evidence of a molecular and functional link between the potassium-chloride co-transporters and the Rho GTPase-dependent actin remodeling machinery in RVD, cell spreading and cell protrusion dynamics, thus providing new insights into KCC3's involvement in cancer cell malignancy and in corpus callosum agenesis in HMSN/ACC.

  12. Integrated Data Collection Analysis (IDCA) Program - KClO4/Carbon Mixture

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-01-31

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4 and activated carbon—KClO4/C mixture. This material was selected because of the challenge of performing SSST testing of a mixture of two solids. The mixture was found to be insensitive to impact, friction, and thermal stimulus, and somewhat sensitive to spark discharge. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO4/carbon mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when these testing variables cannot be made consistent.

  13. An Electrochemical Study of Lanthanide Elements in LiCl-KCl Eutectic Molten Salt to Convert All The Spent Nuclear Fuel into Low and Intermediate Level Waste

    An additional unit step for the residual actinide recovery, designated as 'Pyro-Reisodex', was proposed to convert all the spent nuclear waste into low and intermediated level water by achieving high decontamination factor for TRH elements. The measurement of basic material properties of lanthanide elements in LiCl-KCl eutectic molten salt is necessary to evaluate the performance of the step. Thus, standard potential, activity coefficient, and diffusion coefficient of lanthanide elements is being tried to determine using conventional electrochemical methods. The cycle voltammetry was measured for LiCl-KCl-SmCl3 mixture and the standard potential, activity coefficient, and diffusion coefficient of this system was determined from the voltammogram data. The calculated data was well-agreed with reference. Based on this results, another techniques for other lanthanide elements will be applied for better understanding of LiCl-KCl-LnCln system

  14. Robert K. Crane - Na+-Glucose Cotransporter to Cure?

    KirkLHamilton

    2013-03-01

    Full Text Available Dr. Robert K. Crane made major contributions to our understanding of carbohydrate metabolism and transport of the intestine over a very long and productive career. This Perspective examines, briefly, his early life and academic positions, but more importantly, this Perspective highlights his contributions to the understanding of coupled Na+-glucose absorption by the small intestine. I discuss how his early hypothesis of a ‘cotransport’ of sodium and glucose ushered in and provided the physiological explanation for the clinical treatment of acute diarrhea and cholera when using oral rehydration therapy (ORT. ORT saves millions of lives each year. Certainly, humankind is better off because of Crane’s hypothesis of the Na+-glucose cotransporter which he put forth over 50 years ago?

  15. Water transport by the Na+/glucose cotransporter under isotonic conditions

    Zeuthen, T; Meinild, A K; Klaerke, D A;

    1997-01-01

    Solute cotransport in the Na+/glucose cotransporter is directly coupled to significant water fluxes. The water fluxes are energized by the downhill fluxes of the other substrates by a mechanism within the protein itself. In the present paper we investigate the Na+/glucose cotransporter expressed in...... Xenopus oocytes. We present a method which allows short-term exposures to sugar under voltage clamp conditions. We demonstrate that water is cotransported with the solutes despite no osmotic differences between the external and intracellular solutions. There is a fixed ratio of 195:1 between the number of...... water molecules and the number of Na+ ions transported, equivalent to 390 water molecules per glucose molecule. Unstirred layer effects are ruled out on the basis of experiments on native oocytes incubated with the ionophores gramicidin D or nystatin....

  16. Hydro-chemical conversion of galena in FeCl_3-KCl solution

    LONG Huai-zhong; CHAI Li-yuan; LIU Hui; QIN Wen-qing

    2009-01-01

    The behaviours of complexation and dissolution of PbCl_2 on the surface of galena were investigated to explore the process of hydro-chemical conversion of galena (PbS) in chloride media. By means of solution chemistry calculation, the production and dissolution of the products PbCl_2 were studied. And the passivation of the galena was studied by Tafel curve. The results show that PbCl_4~(2-) is the main form of PbCl_2 presented in the saturated potassium chloride (KCl) solution. The PbCl_2 crystal is easy to precipitate when the total concentration of chloride ion ([Cl-]T) is equal to 0.92 mol/L, and it is inclined to dissolve when [Cl-]T is more than 0.92 mol/L. The chloride complexing reaction rate strongly depends on the Fe~(3+) ion concentration when it is less than 6×10~(-4)mol/L, while passivation occurs on the surface of the electrode when Fe~(3+) concentration is larger than 6×10~(-4)mol/L. The reaction rate increases obviously when KCl is added, since the activity of Cl- increases; thus accelerates the dissolution of PbCl2.

  17. Prediction of Solid-Liquid Equilibrium for KCl in Mixed Water-Ethanol Solutions Using the LIQUAC Model

    LIN Yangzheng; LI Jiding; ZENG Chuyi; CHEN Cuixian

    2005-01-01

    The LIQUAC model is often used to predict vapor-liquid equilibria, osmotic coefficients, and mean ion activity coefficients for electrolyte systems. This paper describes a thermodynamic method to analyze solid-liquid equilibrium for electrolytes in mixed solvents solutions using the LIQUAC model. The KCl solubilities in mixed water-ethanol solutions are predicted with the LIQUAC model and its original interaction parameters. This method is also used to obtain new K+-ethanol interaction parameters in the LIQUAC model from the solubility data. The new interaction parameters accurately predict the vapor-liquid equilibrium data of K+ salts (including KCl, KBr, and KCOOCH3) in mixed water-ethanol solutions. The results illustrate the flexibility of the LIQUAC model which can predict not only vapor-liquid equilibrium but also solid-liquid equilibrium in mixed solvent systems.

  18. Specific heat measurements in KCN:KCL mixed crystals

    An adiabatic calorimeter to perform specific heat measurements of small samples (approximatelly 150 mg) was built. The measurements were taken from 6 to 120 K, iN KCN:KCL mixed crystals, in order to observe the evolution of the antiferroelectric phase transition - that occurs at 83 K in KCN pure. From the experimental results the values of the phase transition critical temperature are found, for some particular concentrations of the mixture, and it was detected that this phase transition disappears with only 10% of Cl-. This result is explained in terms of a change of the potential wells in the crystal. (Author)

  19. Elaboration and Characterization of AuCl Semiconductor Nanocrystals Embedded in KCL Single Crystals

    Hanane Zaioune; Miloud Sebais; Fouzia Zehani

    2012-01-01

    In this work, we investigated the structural and the optical properties of AuCl semiconductor nanocrystals embedded in KCl single crystals. The AuCl nanocrystals were obtained by doping the KCl crystalline matrix with gold using the Czochralski method. The X-ray diffraction showed the formation of the AuCl nanocrystals in KCl with a tetragonal structure. The average radius of the AuCl nanocrystals is estimated using the Scherrer formula. The photoluminescence spectra presented a band emission...

  20. Circular magnetic dichroism of the Fa center adsorption in KCl doped with Li and Na

    The spin-orbit structure of FA in KCl:Li and KCl:Na have been studied by means of the magnetic circular dichroism. Due to their C4V, symmetry the FA centers have two different spin-orbit parameters, Δ* and Δ*, which only in the KCl:Li case follow the relation: Δ* F A centers have been determined using the method of moment

  1. Growth and time dependent alignment of KCl crystals in Hemoglobin LB monolayer

    Nature and organism often use the biomineralization technique to build up various highly regular structures such as bone, teeth, kidney stone etc., and recently this becomes the strategy to design and synthesis of novel biocomposite materials. We report here the controlled crystallization of KCl in Langmuir and Langmuir Blodgett (LB) monolayer of Hemoglobin (Hb) at ambient condition. The nucleation and growth of KCl crystals in Hb monolayer has temporal and KCl concentration dependency. The growth of KCl crystals in LB film of Hb has distinct behavior in the alignment of crystals from linear to fractal like structures depending on growth time. The crystallographic identity of the biomineralized KCl crystal is confirmed from HR-TEM, XRD, and from powder diffraction simulation. Our results substantiated that the template of Langmuir monolayer of proteins plays a crucial role in biomineralization as well as in designing and synthesizing of novel biocomposite materials. Highlights: ► Biomineralization of KCl crystal has been studied in Hemoglobin LB film. ► KCl crystal growth is time and concentration of KCl dependent. ► The alignment of KCl crystal growth is fractal nature with time. ► The unfolding of Hb and evaporation factor has some role in crystallization and fractal growth.

  2. Sodium-glucose co-transporter-2 inhibitors and euglycemic ketoacidosis: Wisdom of hindsight.

    Singh, Awadhesh Kumar

    2015-01-01

    Sodium-glucose co-transporter-2 inhibitors (SGLT-2i) are newly approved class of oral anti-diabetic drugs, in the treatment of type 2 diabetes, which reduces blood glucose through glucouresis via the kidney, independent, and irrespective of available pancreatic beta-cells. Studies conducted across their clinical development program found, a modest reduction in glycated hemoglobin ranging from -0.5 to -0.8%, without any significant hypoglycemia. Moreover, head-to-head studies versus active comparators yielded comparable efficacy. Interestingly, weight and blood pressure reduction were additionally observed, which was not only consistent but significantly superior to active comparators, including metformin, sulfonylureas, and dipeptydylpeptide-4 inhibitors. Indeed, these additional properties makes this class a promising oral anti-diabetic drug. Surprisingly, a potentially fatal unwanted side effect of diabetic ketoacidosis has been noted with its widespread use, albeit rarely. Nevertheless, this has created a passé among the clinicians. This review is an attempt to pool those ketosis data emerging with SGLT-2i, and put a perspective on its implicated mechanism. PMID:26693421

  3. Sodium-glucose co-transporter-2 inhibitors and euglycemic ketoacidosis: Wisdom of hindsight

    Awadhesh Kumar Singh

    2015-01-01

    Full Text Available Sodium-glucose co-transporter-2 inhibitors (SGLT-2i are newly approved class of oral anti-diabetic drugs, in the treatment of type 2 diabetes, which reduces blood glucose through glucouresis via the kidney, independent, and irrespective of available pancreatic beta-cells. Studies conducted across their clinical development program found, a modest reduction in glycated hemoglobin ranging from −0.5 to −0.8%, without any significant hypoglycemia. Moreover, head-to-head studies versus active comparators yielded comparable efficacy. Interestingly, weight and blood pressure reduction were additionally observed, which was not only consistent but significantly superior to active comparators, including metformin, sulfonylureas, and dipeptydylpeptide-4 inhibitors. Indeed, these additional properties makes this class a promising oral anti-diabetic drug. Surprisingly, a potentially fatal unwanted side effect of diabetic ketoacidosis has been noted with its widespread use, albeit rarely. Nevertheless, this has created a passé among the clinicians. This review is an attempt to pool those ketosis data emerging with SGLT-2i, and put a perspective on its implicated mechanism.

  4. Hepatocyte cotransport of taurocholate and bilirubin glucuronides: Role of microtubules

    Modulation of bile pigment excretion by bile salts has been attributed to modification of canalicular membrane transport or a physical interaction in bile. Based on the observation that a microtubule-dependent pathway is involved in the hepatocellular transport of bile salts, the authors investigated the possibility that bilirubin glucuronides are associated with bile salts during intracellular transport. Experiments were conducted in intact rats (basal) or after overnight biliary diversion and intravenous reinfusion of taurocholate (depleted/reinfused). All rats were pretreated with intravenous low-dose colchicine or its inactive isomer lumicolchicine. Biliary excretion of radiolabeled bilirubin glucuronides derived from tracer [14C]bilirubin-[3H]bilirubin monoglucuronide (coinjected iv) was unchanged in basal rats but was consistently delayed in depleted/reinfused rats. This was accompanied by a significant shift toward bilirubin diglucuronide formation from both substrates. In basal Gunn rats, with deficient bilirubin glucuronidation, biliary excretion of intravenous [14C]bilirubin monoglucuronide-[3H]bilirubin diglucuronide was unaffected by colchicine but was retarded in depleted/reinfused Gunn rats. Colchicine had no effect on the rate of bilirubin glucuronidation in vitro in rat liver microsomes. They conclude that a portion of the bilirubin glucuronides generated endogenously in hepatocytes or taken up directly from plasma may be cotransported with bile salts to the bile canalicular membrane via a microtubule-dependent mechanism

  5. The Na+/glucose cotransporters: from genes to therapy

    R. Sabino-Silva

    2010-11-01

    Full Text Available Glucose enters eukaryotic cells via two types of membrane-associated carrier proteins, the Na+/glucose cotransporters (SGLT and the facilitative glucose transporters (GLUT. The SGLT family consists of six members. Among them, the SGLT1 and SGLT2 proteins, encoded by the solute carrier genes SLC5A1 and SLC5A2, respectively, are believed to be the most important ones and have been extensively explored in studies focusing on glucose fluxes under both physiological and pathological conditions. This review considers the regulation of the expression of the SGLT promoted by protein kinases and transcription factors, as well as the alterations determined by diets of different compositions and by pathologies such as diabetes. It also considers congenital defects of sugar metabolism caused by aberrant expression of the SGLT1 in glucose-galactose malabsorption and the SGLT2 in familial renal glycosuria. Finally, it covers some pharmacological compounds that are being currently studied focusing on the interest of controlling glycemia by antagonizing SGLT in renal and intestinal tissues.

  6. Thermoluminiscence and thermal annealing of F centres in KCL gamma irradiated

    The thermoluminiscence spectrum and phosphorescence decays of Harshaw KCl samples gamma irradiated at room temperature have been studied up to 4000C. For the six peaks found, the order of recombination kinetics, the pre-exponential factor and the activation energy have been obtained. It has been observed that the area under the thermoluminiscence curve is always proportional to the F centre concentration in the sample before heating. It was also found that there is an annealing step of F centres corresponding to each thermoluminiscence peak, when the temperature of the sample is raised at a constant rate. It is concluded that the F centres play the role of recombination centres in the annealing process, the interstitials being the mobile entities moving towards there combination centre. At some stage in the process light is emitted. (author)

  7. Thermoluminescence studies in lead doped KCl and KBr crystals

    Lead is known to enter substitutionally in divalent state when doped in alkali halides. When irradiated at room temperature these lead centers (Pb++) act as traps for electrons knocked off from the halogen ions and become Pb+ and Pb0 (for large doses of irradiation). These changes could be followed in the optical absorption studies. These lead-doped crystals after X-ray irradiation yield a thermoluminescence output smaller than that observed in 'pure' crystals. However, two new glow peaks are observed in additions to those due to F-centers. In KCl : Pb and Kbr : Pb crystals part of the F-center glow preceds the new glow peaks. The new peaks are attributed to the Pb+ and Pb0 centers. The glow peak temperatures and trap depths for these peaks an obtained by total-curve fitting method are reported. (author)

  8. Radiational creation of Frenkel defects in KCl-Tl

    Lushchik, C.; Lushchik, N.; Kolk, J.; Lushchik, A.

    1984-11-16

    The process of the formation and thermal annealing of H centers created by X-irradiation at 20 K or by the recombination of electrons optically released from Tl/sup 0/ centers with V/sub K/ centers are studied in KCl-Tl crystals by ESR and optical methods. The yield of the latter process is <= 0.005. Long-lived F, H and ..cap alpha.., I pairs are found to be formed by the creation of near-thallium-localized D excitations by 7.2 to 7.6 eV photons. The differences between the excitonic and the recombination mechanisms of Frenkel defect creation and the role of local vibrations in the production of these defects are considered.

  9. Basic study of TLD-grade KCl:Ba

    The present work involves an in depth study of the thermoluminescent (TL) behaviour of KCl:Ba containing 10-2m.f. Ba concentration. The specimens examined were subjected to different pretreatments. They were obtained by crystallisation from aqueous solution; by air-quenching after annealing at 400oC; and by quenching the melt in open air. It is found that the luminescence efficiency of the melt and quenched specimen is higher than the other two types. The irradiation of the specimens were carried out using radiation from 90Sr beta source (dose 700 rads). The TL-characteristics observed from the above stated variously pretreated specimens are discussed with respect to the defect pattern available in the specimens. (author). 6 refs., 2 figs

  10. High concentrations of KCl release noradrenaline from noradrenergic neurons in the rat anococcygeus muscle

    C.B.L. Araujo

    2003-01-01

    Full Text Available The aim of the present study was to investigate the effects of high concentrations of KCl in releasing noradrenaline from sympathetic nerves and its actions on postsynaptic alpha-adrenoceptors. We measured the isotonic contractions induced by KCl in the isolated rat anococcygeus muscle under different experimental conditions. The contractile responses induced by KCl were inhibited by alpha-adrenoceptor antagonists in 2.5 mM Ca2+ solution. Prazosin reduced the maximum effect from 100 to 53.9 ± 10.2% (P<0.05 while the pD2 values were not changed. The contractile responses induced by KCl were abolished by prazosin in Ca2+-free solution (P<0.05. Treatment of the rats with reserpine reduced the maximum effect induced by KCl as compared to the contractile responses induced by acetylcholine from 339.5 ± 157.8 to 167.3 ± 65.5% (P<0.05, and increased the pD2 from 1.57 ± 0.01 to 1.65 ± 0.006 (P<0.05, but abolished the inhibitory effect of prazosin (P<0.05. In contrast, L-NAME increased the contractile responses induced by 120 mM KCl by 6.2 ± 2.3% (P<0.05, indicating that KCl could stimulate the neurons that release nitric oxide, an inhibitory component of the contractile response induced by KCl. Our results indicate that high concentrations of KCl induce the release of noradrenaline from noradrenergic neurons, which interacts with alpha1-adrenoceptors in smooth muscle cells, producing a contractile response in 2.5 mM Ca2+ (100% and in Ca2+-free solution, part of which is due to a direct effect of KCl on the rat anococcygeus muscle.

  11. Conformational Dynamics of hSGLT1 during Na+/Glucose Cotransport

    Loo, D. D.; Hirayama, B. A.; Karakossian, M. H.;

    2006-01-01

    This study examines the conformations of the Na+/glucose cotransporter (SGLT1) during sugar transport using charge and fluorescence measurements on the human SGLT1 mutant G507C expressed in Xenopus oocytes. The mutant exhibited similar steady-state and presteady-state kinetics as wild-type SGLT1...... membrane voltage elicited presteady-state currents (charge movements) that decay to the steady state with time constants med (3-20 ms, medium) and slow (15-70 ms, slow). Concurrently, SGLT1 rhodamine fluorescence intensity increased with depolarizing and decreased with hyperpolarizing voltages ( F). The...... previously described. This rate-limiting step at maximal inward Na+/sugar cotransport (saturating voltage and external Na+ and sugar concentrations) is the slow release of Na+ from the internal surface of SGLT1. The high affinity blocker phlorizin locks the cotransporter in an inactive conformation....

  12. Cotransport of bismerthiazol and montmorillonite colloids in saturated porous media

    Shen, Chongyang; Wang, Hong; Lazouskaya, Volha; Du, Yichun; Lu, Weilan; Wu, Junxue; Zhang, Hongyan; Huang, Yuanfang

    2015-06-01

    While bismerthiazol [N,N‧-methylene-bis-(2-amino-5-mercapto-1,3,4-thiadiazole)] is one of the most widely used bactericides, the transport of bismerthiazol in subsurface environments is unclear to date. Moreover, natural colloids are ubiquitous in the subsurface environments. The cotransport of bismerthiazol and natural colloids has not been investigated. This study conducted laboratory column experiments to examine the transport of bismerthiazol in saturated sand porous media both in the absence and presence of montmorillonite colloids. Results show that a fraction of bismerthiazol was retained in sand and the retention was higher at pH 7 than at pH 4 and 10. The retention did not change with ionic strength. The retention was attributed to the complex of bismerthiazol with metals/metal oxides on sand surfaces through ligand exchange. The transport of bismerthiazol was enhanced with montmorillonite colloids copresent in the solutions and, concurrently, the transport of montmorillonite colloids was facilitated by the bismerthiazol. The transport of montmorillonite colloids was enhanced likely because the bismerthiazol and the colloids competed for the attachment/adsorption sites on collector surfaces and the presence of bismerthiazol changed the Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energies between colloids and collectors. The transport of bismerthiazol was inhibited if montmorillonite colloids were pre-deposited in sand because bismerthiazol could adsorb onto the colloid surfaces. The adsorbed bismerthiazol could be co-remobilized with the colloids from primary minima by decreasing ionic strength. Whereas colloid-facilitated transport of pesticides has been emphasized, our study implies that transport of colloids could also be facilitated by the presence of pesticides.

  13. Molecular cloning and functional expression of the bumetanide-sensitive Na-K-Cl cotransporter.

    Xu, J. C.; Lytle, C; Zhu, T. T.; Payne, J A; Benz, E; Forbush, B

    1994-01-01

    By mediating the coupled movement of Na, K, and Cl ions across the plasma membrane of most animal cells, the bumetanide-sensitive Na-K-Cl cotransporter (NKCC) plays a vital role in the regulation of ionic balance and cell volume. The transporter is a central element in the process of vectorial salt transport in secretory and absorptive epithelia. A cDNA encoding a Na-K-Cl cotransport protein was isolated from a shark rectal gland library by screening with monoclonal antibodies to the native s...

  14. Na+/HCO3- Cotransport in Normal and Cystic Fibrosis Intestine

    Seidler U; Bachmann O.; Jacob P; Christiani S; Blumenstein I; Rossmann H

    2001-01-01

    In a search for the HCO(3)(-) supply mechanisms to the enterocyte we cloned and sequenced an intestinal subtype of the Na(+)HCO(3)(-) cotransporter isoform I (dNBC1), which turned out to be identical to the pancreatic NBC1 subtype (pNBC1). Within the intestine, we found particularly high NBC1 expression levels in the duodenum and proximal colon. Experiments with stripped rabbit duodenum in Ussing-chambers revealed that Na(+)HCO(3)(-) cotransport (NBC) and CO(2) hydration/Na(+)/H(+) exchange w...

  15. SODIUM-POTASSIUM-CHLORIDE COTRANSPORT IN THE REGULATION OF VASCULAR MYOGENIC TONE

    S. N. Orlov

    2014-01-01

    Full Text Available The article discusses the data on the functioning of Na+,K+,2Cl– cotransport – the carrier providing electroneutral symport of sodium, potassium and chloride, as well as molecular mechanisms of the regulation and physiological significance of this carrier. We analyzed the novel data on involvement of ubiquitous isoform of Na+,K+,2Cl–cotransporter (NKCC1 in regulation of vascular smooth muscle contraction, and role of this carrier in the regulation of cell volume and intracellular chloride concentration.

  16. Differential expression patterns of K(+) /Cl(-) cotransporter 2 in neurons within the superficial spinal dorsal horn of rats.

    Javdani, Fariba; Holló, Krisztina; Hegedűs, Krisztina; Kis, Gréta; Hegyi, Zoltán; Dócs, Klaudia; Kasugai, Yu; Fukazawa, Yugo; Shigemoto, Ryuichi; Antal, Miklós

    2015-09-01

    γ-Aminobutyric acid (GABA)- and glycine-mediated hyperpolarizing inhibition is associated with a chloride influx that depends on the inwardly directed chloride electrochemical gradient. In neurons, the extrusion of chloride from the cytosol primarily depends on the expression of an isoform of potassium-chloride cotransporters (KCC2s). KCC2 is crucial in the regulation of the inhibitory tone of neural circuits, including pain processing neural assemblies. Thus we investigated the cellular distribution of KCC2 in neurons underlying pain processing in the superficial spinal dorsal horn of rats by using high-resolution immunocytochemical methods. We demonstrated that perikarya and dendrites widely expressed KCC2, but axon terminals proved to be negative for KCC2. In single ultrathin sections, silver deposits labeling KCC2 molecules showed different densities on the surface of dendritic profiles, some of which were negative for KCC2. In freeze fracture replicas and tissue sections double stained for the β3-subunit of GABAA receptors and KCC2, GABAA receptors were revealed on dendritic segments with high and also with low KCC2 densities. By measuring the distances between spots immunoreactive for gephyrin (a scaffolding protein of GABAA and glycine receptors) and KCC2 on the surface of neurokinin 1 (NK1) receptor-immunoreactive dendrites, we found that gephyrin-immunoreactive spots were located at various distances from KCC2 cotransporters; 5.7 % of them were recovered in the middle of 4-10-µm-long dendritic segments that were free of KCC2 immunostaining. The variable local densities of KCC2 may result in variable postsynaptic potentials evoked by the activation of GABAA and glycine receptors along the dendrites of spinal neurons. PMID:25764511

  17. ¬Immunolocalization of cation-chloride cotransporters in the developing and mature spinal cord of opossums, Monodelphis domestica

    Jean-François Pflieger

    2013-05-01

    Full Text Available Spinal inhibition is required to generate coordinated outputs between antagonistic muscles during locomotion. It relies on low neuronal chloride concentration set by two cation-chloride cotransporters, NKCC1 and KCC2 which, respectively, pumps Cl- in or out of neurons. It is generally accepted that NKCC1 is gradually inactivated during development, while KCC2 is upregulated and activated, resulting in low intracellular [Cl-]. Newborn opossums are very immature but perform rhythmic and alternate movements of the forelimbs to crawl on the mother’s belly and attach to a teat. Their hindlimbs are immobile. The alternation of the forelimbs suggests that mechanisms allowing spinal inhibition are present at birth. We studied the anatomical basis of inhibition in the spinal enlargements of postnatal opossums by immunolocalizing NKCC1 and KCC2. In some specimens, motoneurons and sensory afferents were labeled with TRDA prior to immunolabeling. At birth, both NKCC1 and KCC2 are detected in the presumptive grey and white matter of the ventral and the intermediolateral cord of both enlargements, but are sparse in the dorsal horn, where KCC2 is mostly seen on a small bundle of dendrites along primary afferents. KCC2 labeling is bright and has a mesh-like appearance in the grey matter and a radial appearance in the white matter, whereas NKCC1 is pale and diffuse. The subsequent expression of the cotransporters follows general ventrodorsal and mediolateral gradients, with the lumbar segments slightly lagging the cervical segments, until the mature pattern is observed around the 5th week. At all ages studied, KCC2 labeling is strong in the periphery of neurons. NKCC1 labeling decreases and becomes more uniformly distributed in the cells with age. Despite the significant anatomical and motor differences between the forelimbs and the hindlimbs of neonatal opossums, the maturation of KCC2 and NKCC1 is quite similar in both enlargements.

  18. Phosphorylation decreases ubiquitylation of the thiazide-sensitive cotransporter NCC and subsequent clathrin-mediated endocytosis.

    Rosenbaek, Lena L; Kortenoeven, Marleen L A; Aroankins, Takwa S; Fenton, Robert A

    2014-05-01

    The thiazide-sensitive sodium chloride cotransporter, NCC, is the major NaCl transport protein in the distal convoluted tubule (DCT). The transport activity of NCC can be regulated by phosphorylation, but knowledge of modulation of NCC trafficking by phosphorylation is limited. In this study, we generated novel tetracycline-inducible Madin-Darby canine kidney type I (MDCKI) cell lines expressing NCC to examine the role of NCC phosphorylation and ubiquitylation on NCC endocytosis. In MDCKI-NCC cells, NCC was highly glycosylated at molecular weights consistent with NCC monomers and dimers. NCC constitutively cycles to the apical plasma membrane of MDCKI-NCC cells, with 20-30% of the membrane pool of NCC internalized within 30 min. The use of dynasore, PitStop2, methyl-β-cyclodextrin, nystatin, and filipin (specific inhibitors of either clathrin-dependent or -independent endocytosis) demonstrated that NCC is internalized via a clathrin-mediated pathway. Reduction of endocytosis resulted in greater levels of NCC in the plasma membrane. Immunogold electron microscopy confirmed the association of NCC with the clathrin-mediated internalization pathway in rat DCT cells. Compared with controls, inducing phosphorylation of NCC via low chloride treatment or mimicking phosphorylation by replacing Thr-53, Thr-58, and Ser-71 residues with Asp resulted in increased membrane abundance and reduced rates of NCC internalization. NCC ubiquitylation was lowest in the conditions with greatest NCC phosphorylation, thus providing a mechanism for the reduced endocytosis. In conclusion, our data support a model where NCC is constitutively cycled to the plasma membrane, and upon stimulation, it can be phosphorylated to both increase NCC activity and decrease NCC endocytosis, together increasing NaCl transport in the DCT. PMID:24668812

  19. A novel strategy for the treatment of diabetes mellitus - sodium glucose co-transport inhibitors

    Asfandyar Khan Niazi

    2010-12-01

    Full Text Available Background: Diabetes is one of the most common chronic diseases, affecting almost 3 million in Canada alone and is characterized by increased blood glucose levels. Treatment varies from lifestyle changes to oral anti-diabetics and/or insulin. Sodium glucose co-transport inhibitors may offer promising treatment for patients suffering from diabetes. The inhibitors act by increasing the loss of glucose in urine by decreasing the reabsorption of glucose from the proximal tubules of nephrons. Aims: The aim of this review was to assess the efficacy of sodium glucose co-transport inhibitors in the treatment of diabetes as well as any adverse effects. Materials and Methods: Databases such as MEDLINE, COCHRANE and EMBASE were systematically searched for literature on the efficacy of sodium glucose co-transport inhibitors in improving the glycemic control of patients with diabetes. Results: Research showed that sodium glucose co-transport inhibitors significantly decreased blood glucose levels by increasing glucosuria. Due to the diuretic effects of these inhibitors, diabetic patients who were suffering from hypertension showed a decrease in blood pressure. The caloric loss associated with these inhibitors resulted in weight loss as well. The most common adverse effect seen in patients on these medications was mycotic infection of the urinary or genital tract. Conclusion: Sodium glucose co-transport inhibitors may be an effective line of treatment for diabetes. Although short-term research has shown these drugs to be safe and well-tolerated, studies should be conducted to assess the long-term effects of these drugs.

  20. A novel strategy for the treatment of diabetes mellitus - sodium glucose co-transport inhibitors

    Asfandyar Khan Niazi

    2010-01-01

    Full Text Available Background: Diabetes is one of the most common chronic diseases, affecting almost 3 million in Canada alone and is characterized by increased blood glucose levels. Treatment varies from lifestyle changes to oral anti-diabetics and/or insulin. Sodium glucose co-transport inhibitors may offer promising treatment for patients suffering from diabetes. The inhibitors act by increasing the loss of glucose in urine by decreasing the reabsorption of glucose from the proximal tubules of nephrons. Aims: The aim of this review was to assess the efficacy of sodium glucose co-transport inhibitors in the treatment of diabetes as well as any adverse effects. Materials and Methods : Databases such as MEDLINE, COCHRANE and EMBASE were systematically searched for literature on the efficacy of sodium glucose co-transport inhibitors in improving the glycemic control of patients with diabetes. Results: Research showed that sodium glucose co-transport inhibitors significantly decreased blood glucose levels by increasing glucosuria. Due to the diuretic effects of these inhibitors, diabetic patients who were suffering from hypertension showed a decrease in blood pressure. The caloric loss associated with these inhibitors resulted in weight loss as well. The most common adverse effect seen in patients on these medications was mycotic infection of the urinary or genital tract. Conclusion: Sodium glucose co-transport inhibitors may be an effective line of treatment for diabetes. Although short-term research has shown these drugs to be safe and well-tolerated, studies should be conducted to assess the long-term effects of these drugs.

  1. Template-Directed Directionally Solidified 3D Mesostructured AgCl-KCl Eutectic Photonic Crystals.

    Kim, Jinwoo; Aagesen, Larry K; Choi, Jun Hee; Choi, Jaewon; Kim, Ha Seong; Liu, Jinyun; Cho, Chae-Ryong; Kang, Jin Gu; Ramazani, Ali; Thornton, Katsuyo; Braun, Paul V

    2015-08-19

    3D mesostructured AgCl-KCl photonic crystals emerge from colloidal templating of eutectic solidification. Solvent removal of the KCl phase results in a mesostructured AgCl inverse opal. The 3D-template-induced confinement leads to the emergence of a complex microstructure. The 3D mesostructured eutectic photonic crystals have a large stop band ranging from the near-infrared to the visible tuned by the processing. PMID:26177830

  2. Solubility polytherms of NaCl(KCl)-GdCl3-H2O system

    The isothermal method in the temperature range from 25 up to 100 deg C has been used to study the solubility in the NaCl-GdCl3-H2O and KCl-GdCl3-H2O systems. The limits of the NaCl, KCl and GdCl3x6H2O crystallization are discriminated. Solubility polytherms of the systems are plotted

  3. Electrochemical formation of Sc-Al intermetallic compounds in the eutectic LiCl-KCl. Determination of thermodynamic properties

    Graphical abstract: - Highlights: • The formation mechanism of AlxScy intermetallic compounds was studied in the eutectic LiCl-KCl • The formation energy, global and consecutive formation constants of AlxScy were estimated from OCP. • XRD after potentiostatic electrolysis, allowed the identification of Al3Sc and Al2Sc • XRD after intermittent galvanostatic electrolysis allowed the identification of Al3Sc, Al2Sc and AlSc2 • SEM with EDX, allowed the identification of Al3Sc, Al2Sc, AlSc and AlSc2. - Abstract: The electrochemical formation of Sc-Al alloys was investigated in the eutectic LiCl-KCl by cyclic voltammetry and open circuit chronopotentiometry. On reactive Al electrode the electrochemical reduction of Sc(III) was observed at less cathodic potential values than at the surface of an inert W electrode, the potential shift is caused by the decrease of Sc activity in the metal phase due to the formation of Sc-Al intermetallic compounds at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sc(III) and Al(III) ions, using a W electrode, and ii) Sc(III) ions using an Al electrode. Analysis of the samples after electrolysis runs by X-ray diffraction allowed the identification of Al3Sc and Al2Sc, whereas analysis by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al3Sc, Al2Sc, AlSc and AlSc2. The formation energy of each AlxScy intermetallic compound, and the global and stepwise formation constant were estimated from open circuit chronopotentiometry measurements in the eutectic LiCl-KCl at 723 and 773 K using Al as working electrode

  4. Thermodynamics of HfCl4-KCl molten mixtures containing HfCl4 up to 33.3 mol. per cent

    Based on measurements of saturated vapour pressure in components of melted mixtures of HfCl4-KCl, depending on temperature and concentration, calculated are the results of changes in activity coefficients of hafnium tetrachloride and potassium chloride on transition from diluted solutions, where the Henry law is met, to those concentrated where the law is disobeyed. Growth in the activity coefficient of HfCl4 is due to dissociation of complex groups of HfCl62- into complexes with a lesser number of ligands and decreasing relative binding energy of Hf4+-Cl- there. In this case, marked changes take place in partial enthalpy and entropy of hafnium tetrachloride mixing. Similar dependences are observed for potassium chloride, but they are expressed considerably weaker. Evaporation enthalpy and entropy are calculated for HfCl4 and KCl monomers from their melted mixtures of various concentrations

  5. Thermodynamics of separation of uranium from neodymium between the gallium-indium liquid alloy and the LiCl-KCl molten salt phases

    Highlights: • The behavior of neodymium and uranium on liquid gallium-indium eutectic alloy was carried out. • The experiments were done in fused LiCl-KCl eutectic vs. Cl-/Cl2 reference electrode at the temperature range 723-823 K. • Thermodynamic properties of Nd-Ga-In alloy and the separation factor U/Nd were calculated. - Abstract: This work presents the electrochemical study of neodymium and uranium compounds in fused LiCl-KCl eutectic vs. Cl-/Cl2 reference electrode in the temperature range 723-823 K on liquid gallium-indium eutectic alloy. The activity, solubility and the activity coefficients of neodymium were calculated. The separation factor of uranium from neodymium on gallium-indium eutectic alloy was determined. The obtained data show the perspective of used this system in future innovation method for recovery of nuclear waste

  6. Determination of mendelevium (1+) ionic radius and MdCl solubility on the basis of its isomorphous cocrystallization with NaCl and KCl

    On the basis of previously obtained exlperimental data on coefficients of cocrystallization of microamounts of MdCl with NaCl and KCl in water-ethanol solutions the calculation of ionic radius of mendelevium (1+) are made. It turned out that for coordination number 6 value Rsub(Mdsup(+))=0.117 nm, which agrees with theoretically calculated value. Solubility and product of MdCl activity in water-ethanol solutions of different compositions at 25 deg are calculated

  7. General anaesthetics do not impair developmental expression of the KCC2 potassium-chloride cotransporter in neonatal rats during the brain growth spurt

    Lacoh, Claudia Marvine

    2013-03-26

    BackgroundThe developmental transition from depolarizing to hyperpolarizing γ-aminobutyric acid-mediated neurotransmission is primarily mediated by an increase in the amount of the potassium-chloride cotransporter KCC2 during early postnatal life. However, it is not known whether early neuronal activity plays a modulatory role in the expression of total KCC2 mRNA and protein in the immature brain. As general anaesthetics are powerful modulators of neuronal activity, the purpose of this study was to explore how these drugs affect KCC2 expression during the brain growth spurt.MethodsWistar rat pups were exposed to either a single dose or 6 h of midazolam, propofol, or ketamine anaesthesia at postnatal days 0, 5, 10, or 15. KCC2 expression was assessed using immunoblotting, immunohistochemistry, or quantitative polymerase chain reaction analysis up to 3 days post-exposure in the medial prefrontal cortex.ResultsThere was a progressive and steep increase in the expression of KCC2 between birth and 2 weeks of age. Exposure to midazolam, propofol, or ketamine up to 6 h at any investigated stages of the brain growth spurt did not influence the expression of this cotransporter protein.ConclusionI.V. general anaesthetics do not seem to influence developmental expression of KCC2 during the brain growth spurt. © 2013 © The Author [2013].

  8. Electrochemical behavior of actinides and actinide nitrides in LiCl-KCl eutectic melts

    The redox potentials of the U3+/U, Np3+/Np and Pu3+/Pu couples at Mo, Cd and Bi electrodes in LiCl-KCl eutectic melt containing UCl3, NpCl3 and PuCl3, respectively, were evaluated by electrochemical measurements at the temperature range between 723 and 823K. The standard potentials of the U3+/U, Np3+/Np and Pu3+/Pu couples versus the Ag+/Ag (1wt.% AgCl) reference electrode were given by the following equations: EU3+/U0=-1.8647+0.000798xT, ENp3+/Np0=-2.0298+0.000706xT and EPu3+/Pu0=-2.232+0.00094xT, where E values are in volts, T in kelvin. The differences between the redox potentials at Mo electrode and those at liquid metal electrodes were attributable to the lowering in the activities of U, Pu and Np in liquid metal phases according to the alloy formation. Similarly, the anodic dissolutions of UN, NpN and PuN were observed at about 0.7V more positive potential than those of U, Np and Pu, respectively, since the stabilization of U, Np and Pu by nitriding lowered the activities of U, Np and Pu, respectively, in the solid phase

  9. Voltage and cosubstrate dependence of the Na-HCO3 cotransporter kinetics in renal proximal tubule cells.

    Gross, E.; Hopfer, U

    1998-01-01

    The voltage dependence of the kinetics of the sodium bicarbonate cotransporter was studied in proximal tubule cells. This electrogenic cotransporter transports one Na+, three HCO3-, and two negative charges. Cells were grown to confluence on a permeable support, mounted on a Ussing-type chamber, and permeabilized apically to small monovalent ions with amphotericin B. The steady-state, di-nitro-stilbene-di-sulfonate-sensitive current was shown to be sodium and bicarbonate dependent and therefo...

  10. Flozins, inhibitors of type 2 renal sodium-glucose co-transporter – not only antihyperglycemic drugs

    Mizerski Grzegorz; Kicinski Pawel; Jaroszynski Andrzej

    2015-01-01

    The kidneys play a crucial role in the regulation of the carbohydrate metabolism. In normal physiological conditions, the glucose that filters through the renal glomeruli is subsequently nearly totally reabsorbed in the proximal renal tubules. Two transporters are engaged in this process: sodium-glucose co-transporter type 1 (SGLT1), and sodium-glucose co-transporter type type 2 (SGLT2) - this being located in the luminal membrane of the renal tubular epithelial cells. It was found that the a...

  11. Sodium-glucose cotransporter 2 inhibition and cardiovascular risk reduction in patients with type 2 diabetes: the emerging role of natriuresis.

    Rajasekeran, Harindra; Lytvyn, Yuliya; Cherney, David Z I

    2016-03-01

    Inhibition of sodium-glucose cotransporter 2 causes both glycosuria and natriuresis, leading to reductions in hyperglycemia, body weight, blood pressure, and proteinuria. The recently published EMPA-REG OUTCOME study demonstrated significant cardiovascular and mortality benefits of sodium-glucose cotransporter 2 inhibition with empagliflozin in patients with type 2 diabetes and established cardiovascular disease, and may suggest a broader role for sodium-glucose cotransporter 2 inhibition in patients with heart failure. PMID:26880444

  12. Abnormal Expression of Cerebrospinal Fluid Cation Chloride Cotransporters in Patients with Rett Syndrome

    Sofia Temudo Duarte; Judith Armstrong; Ana Roche; Carlos Ortez; Ana Pérez; Maria del Mar O'Callaghan; Antonina Pereira; Francesc Sanmartí; Aida Ormazábal; Rafael Artuch; Mercedes Pineda; Angels García-Cazorla

    2013-01-01

    OBJECTIVE: Rett Syndrome is a progressive neurodevelopmental disorder caused mainly by mutations in the gene encoding methyl-CpG-binding protein 2. The relevance of MeCP2 for GABAergic function was previously documented in animal models. In these models, animals show deficits in brain-derived neurotrophic factor, which is thought to contribute to the pathogenesis of this disease. Neuronal Cation Chloride Cotransporters (CCCs) play a key role in GABAergic neuronal maturation, and brain-derived...

  13. Sodium-glucose co-transporter 2 (SGLT2) inhibitors: a growing class of antidiabetic agents

    Vivian, Eva M

    2014-01-01

    Although several treatment options are available to reduce hyperglycemia, only about half of individuals with diagnosed diabetes mellitus (DM) achieve recommended glycemic targets. New agents that reduce blood glucose concentrations by novel mechanisms and have acceptable safety profiles are needed to improve glycemic control and reduce the complications associated with type 2 diabetes mellitus (T2DM). The renal sodium-glucose co-transporter 2 (SGLT2) is responsible for reabsorption of most o...

  14. Sodium-glucose cotransporter 2 inhibitors with insulin in type 2 diabetes: Clinical perspectives

    Mathew John; Deepa Gopinath; Rejitha Jagesh

    2016-01-01

    The treatment of type 2 diabetes is a challenging problem. Most subjects with type 2 diabetes have progression of beta cell failure necessitating the addition of multiple antidiabetic agents and eventually use of insulin. Intensification of insulin leads to weight gain and increased risk of hypoglycemia. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of antihyperglycemic agents which act by blocking the SGLT2 in the proximal tubule of the kidney. They have potential benefits in...

  15. The Structural Pathway for Water Permeation through Sodium-Glucose Cotransporters

    Sasseville, Louis J.; Cuervo, Javier E.; Lapointe, Jean-Yves; Noskov, Sergei Y.

    2011-01-01

    Although water permeation across cell membranes occurs through several types of membrane proteins, the only permeation mechanism resolved at atomic scale is that through aquaporins. Crystallization of the Vibrio parahaemolyticus sodium-galactose transporter (vSGLT) allows investigation of putative water permeation pathways through both vSGLT and the homologous human Na-glucose cotransporter (hSGLT1) using computational methods. Grand canonical Monte Carlo and molecular dynamics simulations we...

  16. Sodium-Glucose Cotransporter 2 Inhibitors: Possible Anti-Atherosclerotic Effects Beyond Glucose Lowering

    Yanai, Hidekatsu; Katsuyama, Hisayuki; Hamasaki, Hidetaka; Adachi, Hiroki; Moriyama, Sumie; Yoshikawa, Reo; Sako, Akahito

    2015-01-01

    The new drug for type 2 diabetes, the sodium-glucose cotransporter 2 (SGLT-2) inhibitor, is reversible inhibitor of SGLT-2, leading to reduction of renal glucose reabsorption and decrease of plasma glucose, in an insulin-independent manner. In addition to glucose control, the management of coronary risk factors is very important for patients with diabetes. Here we reviewed published articles about the possible anti-atherosclerotic effects beyond glucose lowering of the SGLT-2 inhibitors. We s...

  17. Ipragliflozin: A novel sodium-glucose cotransporter 2 inhibitor developed in Japan

    Ohkura, Tsuyoshi

    2015-01-01

    Sodium-glucose cotransporter 2 (SGLT2) inhibition induces glucosuria and decreases blood glucose levels in diabetic patients and lowers hypoglycemic risk. SGLT1 is expressed in the kidney and intestine; SGLT1 inhibition causes abdominal symptoms such as diarrhea and reduces incretin secretion. Therefore, SGLT2 selectivity is important. Ipragliflozin is highly selective for SGLT2. In type 2 diabetes mellitus (T2DM), urinary glucose excretion increased to 90 g/24 h after 28 d of treatment with ...

  18. The role of phosphorylation in the regulation of the Sodium/D-Glucose cotransporter SGLT1

    Subramanian, Supriya

    2006-01-01

    In der vorliegenden Arbeit wurde der Effekt von Proteinphosphorylierung auf die Funktion und Konformation des Natrium/D- Glucose Cotransporter 1 (SGLT1) untersucht. Mögliche Auswirkungen auf die Funktion von SGLT1 wurden in intakten Zellen anhand der Effekte von Kinaseaktivatoren und -inhibitoren auf die Transportaktivität, die Lokalisation und die Präsenz des Transporters an der Zelloberfläche studiert. Durch Phosphorylierung induzierte Konformationsänderungen wurden an gereinigt...

  19. Kinetics of the B1-B2 phase transition in KCl under rapid compression

    Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Park, Changyong; Kono, Yoshio; Kenney-Benson, Curtis; Rod, Eric; Shen, Guoyin

    2016-01-01

    Kinetics of the B1-B2 phase transition in KCl has been investigated under various compression rates (0.03-13.5 GPa/s) in a dynamic diamond anvil cell using time-resolved x-ray diffraction and fast imaging. Our experimental data show that the volume fraction across the transition generally gives sigmoidal curves as a function of pressure during rapid compression. Based upon classical nucleation and growth theories (Johnson-Mehl-Avrami-Kolmogorov theories), we propose a model that is applicable for studying kinetics for the compression rates studied. The fit of the experimental volume fraction as a function of pressure provides information on effective activation energy and average activation volume at a given compression rate. The resulting parameters are successfully used for interpreting several experimental observables that are compression-rate dependent, such as the transition time, grain size, and over-pressurization. The effective activation energy (Qeff) is found to decrease linearly with the logarithm of compression rate. When Qeff is applied to the Arrhenius equation, this relationship can be used to interpret the experimentally observed linear relationship between the logarithm of the transition time and logarithm of the compression rates. The decrease of Qeff with increasing compression rate results in the decrease of the nucleation rate, which is qualitatively in agreement with the observed change of the grain size with compression rate. The observed over-pressurization is also well explained by the model when an exponential relationship between the average activation volume and the compression rate is assumed.

  20. Kinetics of the B1-B2 phase transition in KCl under rapid compression

    Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Park, Changyong; Kono, Yoshio; Kenney-Benson, Curtis; Rod, Eric; Shen, Guoyin, E-mail: gshen@ciw.edu [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439 (United States)

    2016-01-28

    Kinetics of the B1-B2 phase transition in KCl has been investigated under various compression rates (0.03–13.5 GPa/s) in a dynamic diamond anvil cell using time-resolved x-ray diffraction and fast imaging. Our experimental data show that the volume fraction across the transition generally gives sigmoidal curves as a function of pressure during rapid compression. Based upon classical nucleation and growth theories (Johnson-Mehl-Avrami-Kolmogorov theories), we propose a model that is applicable for studying kinetics for the compression rates studied. The fit of the experimental volume fraction as a function of pressure provides information on effective activation energy and average activation volume at a given compression rate. The resulting parameters are successfully used for interpreting several experimental observables that are compression-rate dependent, such as the transition time, grain size, and over-pressurization. The effective activation energy (Q{sub eff}) is found to decrease linearly with the logarithm of compression rate. When Q{sub eff} is applied to the Arrhenius equation, this relationship can be used to interpret the experimentally observed linear relationship between the logarithm of the transition time and logarithm of the compression rates. The decrease of Q{sub eff} with increasing compression rate results in the decrease of the nucleation rate, which is qualitatively in agreement with the observed change of the grain size with compression rate. The observed over-pressurization is also well explained by the model when an exponential relationship between the average activation volume and the compression rate is assumed.

  1. Kinetics of the B1-B2 phase transition in KCl under rapid compression

    Kinetics of the B1-B2 phase transition in KCl has been investigated under various compression rates (0.03–13.5 GPa/s) in a dynamic diamond anvil cell using time-resolved x-ray diffraction and fast imaging. Our experimental data show that the volume fraction across the transition generally gives sigmoidal curves as a function of pressure during rapid compression. Based upon classical nucleation and growth theories (Johnson-Mehl-Avrami-Kolmogorov theories), we propose a model that is applicable for studying kinetics for the compression rates studied. The fit of the experimental volume fraction as a function of pressure provides information on effective activation energy and average activation volume at a given compression rate. The resulting parameters are successfully used for interpreting several experimental observables that are compression-rate dependent, such as the transition time, grain size, and over-pressurization. The effective activation energy (Qeff) is found to decrease linearly with the logarithm of compression rate. When Qeff is applied to the Arrhenius equation, this relationship can be used to interpret the experimentally observed linear relationship between the logarithm of the transition time and logarithm of the compression rates. The decrease of Qeff with increasing compression rate results in the decrease of the nucleation rate, which is qualitatively in agreement with the observed change of the grain size with compression rate. The observed over-pressurization is also well explained by the model when an exponential relationship between the average activation volume and the compression rate is assumed

  2. Preparation and Humidity Sensing Properties of KCl/MCM-41 Composite

    KCl/mobil composition of matter-41 (MCM-41) composite has been synthesized via a heat-treating process and characterized by x-ray diffraction, high resolution transmission electron microscopy, and nitrogen adsorption/desorption isotherms. In contrast with pure MCM-41, KCl/MCM-41 composite exhibits improved humidity sensing properties within the relative humidity range of 11–95%. The impedance of KCl/MCM-41 composite changes by about four orders of magnitude over the whole humidity range with the response time and the recovery times are about 30 s and 35 s, respectively. Small humidity hysteresis and good stability are also observed based on our product. These results make our product a good candidate in fabricating humidity sensors with high performances and low synthetic complexity

  3. Electrochemical studies on the reduction behaviour of Th4+ in molten LiCl-KCl eutectic

    The electrochemistry of Th4+ ions was studied in LiCl-KCl eutectic in the temperature range 698–803 K and compared with literature data. Various transient electrochemical techniques like cyclic voltammetry, chronopotentiometry, square-wave voltammetry were used to determine diffusion co-efficient of Th4+ and apparent standard electrode potential for Th4+/Th electrode process. The electrode kinetics of Th4+/Th couple was also investigated by convolution voltammetry and impedance spectroscopy. Based on the above studies, the reversibility of Th4+/Th couple was addressed. The feasibility of electrochemical separation of uranium and thorium in LiCl-KCl eutectic is also discussed in this paper. It was seen that the separation of U from Th matrix was difficult in molten LiCl-KCl using a solid rod cathode and suitable reactive electrodes need to be used for efficient separation

  4. Integrated Data Collection Analysis (IDCA) Program - KClO4/Aluminum Mixture

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC IHD), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC IHD), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC IHD), Indian Head, MD (United States). Indian Head Division; Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates (ARA), Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-01-17

    The Integrated Data Collection Analysis (IDCA) program is conducting a Proficiency Test for Small-Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4 and aluminum—KClO4/Al mixture. This material was selected because of the challenge of performing SSST testing of a mixture of two solids. The mixture was found to be: 1) much less sensitive to impact than RDX, (LLNL being the exception) and PETN, 2) more sensitive to friction than RDX and PETN, and 3) extremely sensitive to spark. The thermal analysis showed little or no exothermic character. One prominent endothermic feature was observed in the temperature range studied and identified as a phase transition of KClO4.

  5. Assignment of the human Na[sup +]/glucose cotransporter gene SGLT1 to chromosome 22q13. 1

    Turk, E.; Klisak, I.; Bacallao, R.; Sparkes, R.S.; Wright, E.M. (UCLA School Medicine, Los Angeles, CA (United States))

    1993-09-01

    The Na[sup +]/glucose cotransporter gene SGLT1 encodes the primary carrier protein responsible for the uptake of the dietary sugars glucose and galactose from the intestinal lumen. SGLT1 transport activity is currently exploited in oral rehydration therapy. The 75-kDa glycoprotein is localized in the brush border of the intestinal epithelium and is predicted to comprise 12 membrane spans. In two patients with the autosomal recessive disease glucose/galactose malabsorption, the underlying cause was found to be a missense mutation in SGLT1, and the Asp28 [yields] Asn change was demonstrated in vitro to eliminate SGLT1 transport activity. The SGLT1 gene was previously shown to reside on the distal q arm of chromosome 22(11.2 [yields] qter). The authors have used a cosmid probe for fluorescence in situ hybridization, which refines the localization to 22q13.1, and provide an example of the utility of the SGLT1 probe as a diagnostic for genetic diseases associated with trans-locations of chromosome 22. 18 refs., 2 figs.

  6. Electrode processes in KCl-KF melt of eutectic composition, containing Gd2O3

    Electric reduction of gadolinium ions from eutectic melt KCl-KF with gadolinium oxide additions (0.210-1.233 wt. %) at a temperature of 1008 K on molybdenum and glass carbon electrodes was studied. Solubility of gadolinium oxide in the range of temperatures 610-922 deg C was determined. It is shown that reduction of gadolinium oxofluoride complex takes place reversibly with subsequent reversible chemical reaction. Gadolinium reduction on iron electrode in eutectic solution KCl-KF treated for unwanted oxide-ion impurities involves formation of iron-gadolinium alloy

  7. Charging and defect formation in the KCl-Si(111) thin layers under slow electron irradiation

    The processes of defect formation and charge accumulation in thin KCl-Si(111) films irradiated with electron beam of energies 4-300 e V was studied by total current spectroscopy methods. It was shown that by irradiated electron beam energies Ep ≥ 8 eV in low energies regions of spectrum the peak characteristic for F-, M- and R-centers appeared. Defects formation threshold in KCl was equal to forbidden band energies. The growth of concentration F-, M- and R-centers with increasing irradiated dose and energies was observed. Electron bombardment is accompanied by accumulation of surface charges are connected with captured electrons and hole traps

  8. Emission of thermally stimulated luminescence in mixed monocrystals KCl-KBr: Pb2+, KCl: Pb2+ and KBr: Pb2+ exposed at low doses

    It is reported the behavior of solid solutions of mixed crystals KCl1-x KBrx doped with divalent lead which were exposed to gamma radiation. The mixtures of KCl-KBr were varied, with x equivalents at 2, 50, 65, and 85 % including the extremes KCl: Pb2+ and KBr: Pb2+. It was maintained a concentration of divalent lead between 20 and 40 ppm in the crystalline lattice. The production of the generated defects by radiation have been correlated with the increase in the brilliance curves depending on the received dose by the mixed doped crystal. It has been used the thermal stimulation (Tl) for obtaining the crystal luminescence depending on the dose until 130 Gy with gammas of cobalt 60. The results shows that this mixed crystalline material of varied composition responds adequately to low doses which indicates that this would be a good detector of ionizing radiation. The results have been correlated with the optical properties of this mixed doped crystal, however it has been found that exists an important loss of luminescence depending on the halogen quantity presents in the mixed crystal. (Author)

  9. Activation of the TASK-2 channel after cell swelling is dependent on tyrosine phosphorylation

    Kirkegaard, Signe Skyum; Lambert, Ian Henry; Gammeltoft, Steen; Hoffmann, Else Kay

    2010-01-01

    (K,vol) indicating that inhibition of RVD reflects inhibition of TASK-2. We find that in EATC the tyrosine kinase inhibitor genistein inhibits RVD by 90%, and that the tyrosine phosphatase inhibitor monoperoxo(picolinato)-oxo-vanadate(V) [mpV(pic)] shifted the volume set point for inactivation of the channel to a...... lower cell volume. Swelling-activated K(+) efflux was impaired by genistein and the Src kinase family inhibitor 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2) and enhanced by the tyrosine phosphatase inhibitor mpV(pic). With the use of the TASK-2 inhibitor clofilium, it is...... demonstrated that mpV(pic) increased the volume-sensitive part of the K(+) efflux 1.3 times. To exclude K(+) efflux via a KCl cotransporter, cellular Cl(-) was substituted with NO(3)(-). Also under these conditions K(+) efflux was completely blocked by genistein. Thus tyrosine kinases seem to be involved in...

  10. Furosemide-induced airway relaxation in guinea pigs: relation to Na-K-2Cl cotransporter function.

    Lavallee, S L; Iwamoto, L M; Claybaugh, J R; Dressel, M V; Sato, A K; Nakamura, K T

    1997-07-01

    This study tested the hypothesis that airway relaxation to furosemide is mediated via the Na-K-2Cl cotransporter. If this mechanism exists in airway smooth muscle like in vascular smooth muscle, changes in airway relaxation should be associated with changes in Na-K-2Cl cotransporter function, and both should be substrate dependent. Tracheal rings from newborn guinea pigs were bathed in standard (STD) or varying low Cl- concentration ([Cl-]) N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES). Isometric relaxation to 300 microM furosemide or 10(-8) to 10(-5) M salbutamol was measured. Airway segments were incubated with rubidium-86 (86Rb) in STD or varying low [Cl-] HEPES, with and without 300 microM furosemide or 25 microM salbutamol. Furosemide was unable to reduce 86Rb uptake at 10 mM [Cl-], although relaxation was still observed in 10 mM [Cl-]. Salbutamol did not affect 86Rb uptake. This study demonstrated that there is a furosemide-sensitive Na-K-2Cl cotransporter in newborn guinea pig trachea. However, the effect of furosemide on cotransporter function did not always directly correspond to differences in relaxation, suggesting that the Na-K-2Cl cotransporter may play a major, but not exclusive, role in furosemide-induced airway relaxation. PMID:9252558

  11. Electrochemistry of thorium fluoride in LiCl-KCl eutectic melts and methodology for speciation studies with fluorides ions

    This paper reports the electrochemical behavior of ThF4 in LiCl-KCl molten salt. It proposes a potentiometric method to determine the complexation constants of thorium (IV) with fluorides. The knowledge of these constants leads to calculate the speciation diagram of Th(IV) species as a function of the concentration of fluoride ions in the salt. These results were extrapolate to give an estimation of the activity coefficient of ThF4 in the molten salt LiF-ThF4 (77.5-22.5 mol%). This salt is retained for the molten salt fast reactor system, currently studied as a Generation IV concept in the domain of nuclear energy

  12. Sodium-glucose cotransporter-2 inhibitors and blood pressure decrease: a valuable effect of a novel antidiabetic class?

    Imprialos, Konstantinos P; Sarafidis, Pantelis A; Karagiannis, Asterios I

    2015-11-01

    Diabetes mellitus is a major issue of public health, affecting more than 300 million people worldwide. Inhibitors of the sodium-glucose cotransporter-2 (SGLT-2) in the renal proximal tubule are a novel class of agents for the treatment of type 2 diabetes mellitus. Inhibition of the SGLT-2 results in reduced glucose reabsorption and improvement in glycemic control. Alongside glucose excretion, SGLT-2 inhibitors also have mild natriuretic and diuretic effects, combining actions of a proximal tubule diuretic and an osmotic diuretic; these properties are expected to lead to small blood pressure (BP) reductions. Clinical studies with dapagliflozin, canagliflozin, empagliflozin, ipragliflozin, luseogliflozin, and tofogliflozin used either as monotherapy or add-on therapy and compared with placebo or active treatment have also examined the effect of these agents on BP as a secondary endpoint. Although with some differences between individual agents, all of the approved SGLT-2 inhibitors provided a mild but meaningful reduction in office SBP and DBP. Recent studies with the use of ambulatory blood pressure monitoring suggest that the magnitude of this BP reduction can be even greater. The aim of this review is to systematically summarize and present the studies reporting the effect of approved SGLT-2 inhibitors on BP. PMID:26372321

  13. Electrodeposition of cerium from fused mixture of CeCl sub(3)+NaCl-KCl

    Metallic cerium has been prepared by fused salt electrolysis of 30% CeCl sub(3)+ NaCl-KCl (equimolar) mixture, in the temperature ranged 650-850 sup(0)C, in argon atmosphere. The metal nodules were collected from solidified salts bath. Analysis of these nodules has been done and a 97,3% metallic cerium was obtained. (author)

  14. Life at high salt concentrations, intracellular KCl concentrations, and acidic proteomes

    Aharon eOren

    2013-11-01

    Full Text Available Extremely halophilic microorganisms that accumulate KCl for osmotic balance (the Halobacteriaceae, Salinibacter have a large excess of acidic amino acids in their proteins. This minireview explores the occurrence of acidic proteomes in halophiles of different physiology and phylogenetic affiliation. For fermentative bacteria of the order Halanaerobiales, known to accumulate KCl, an acidic proteome was predicted. However, this is not confirmed by genome analysis. The reported excess of acidic amino acids is due to a high content of Gln and Asn, which yield Glu and Asp upon acid hydrolysis. The closely related Halorhodospira halophila and Halorhodospira halochloris use different strategies to cope with high salt. The first has an acidic proteome and accumulates high KCl concentrations at high salt concentrations; the second does not accumulate KCl and lacks an acidic proteome. Acidic proteomes can be predicted from the genomes of some moderately halophilic aerobes that accumulate organic osmotic solutes (Halomonas elongata, Chromohalobacter salexigens and some marine bacteria. Based on the information on cultured species it is possible to understand the pI profiles predicted from metagenomic data from hypersaline environments.

  15. Heteroepitaxial strain in alkali halide thin films: KCl on NaCl

    Baker, J.; Lindgård, Per-Anker

    1999-01-01

    We have pet-formed Monte Carlo simulations of the properties of a NaCl (001) surface covered by full or partial layers of KCl, for coverages up to 5 monolayers (ML). A wide variety of structures of the film is found. For integer ML coverages we find the continuous, so-called floating mode rumple ...

  16. Electron paramagnetic resonance of K3Rh(CN)6 irradiated with electrons in KCl

    Using a simple theory, it was estimated the electronic density of the diamagnetic complex Rh (CN)3-6 in a KCl lattice. The g// and g1 values were determined by EPR, and the experimental results fit the theoretical calculations. (M.W.O.)

  17. Single PTCDA molecules on planar and stepped KCl and NaCl(100) surfaces

    Aldahhak, H.; Schmidt, W. G.; Rauls, E.

    2015-11-01

    First principles calculations have been employed to investigate the adsorption of single PTCDA molecules on KCl(100) and NaCl(100) surfaces. The lateral and rotational diffusion barriers as well as the electronic and the geometric aspects of single PTCDA molecules adsorbed on planar terraces as well as at defective steps have been studied in detail.

  18. Adsorption of PTCDA on NaCl(100) and KCl(100)

    Aldahhak, H.; Schmidt, W. G.; Rauls, E.

    2013-11-01

    The adsorption of PTCDA on KCl and NaCl(100) surfaces has been investigated by means of first principles calculations. Besides a variety of adsorbate structures for single molecules and a monolayer of flat lying molecules on plain terraces, the influence of monoatomic steps and the different defect site at step edges has been studied in detail.

  19. Development of a specific oxide ion electrode for KCl-LiCl eutectic melts

    The development of a specific oxide ion electrode for use in KCl-LiCl melts at 450 deg C is described. A zirconia tube stabilized with 8 w/o yttria serves as the solid electrolyte membrane for the electrode. In a concentration cell arrangement, the potential of the electrode responds as theoretically expected to changes in oxide ion concentration in the melt

  20. Regulation of the type Mb sodium-dependent phosphate cotransporter expression in the intestine

    Bin WANG; Yulong YIN

    2009-01-01

    Phosphate (Pi) plays important roles in growth, development, bone mineralization, energy metabolism, nucleic acid synthesis, cell signaling, and acid-base regulation. The rate of intestinal absorption of Pi is a major determinant of Pi homeostasis. The type lib sodium- dependent Pi cotransporter (NaPi-Iib) is responsible for intestinal Pi absorption. Many physiological factors regulate the rate of Pi absorption via modulating the expression of NaPi-Iib in the intestine. In this review, we summarize the role of these factors in the regulation of NaPi-Iib expression in the intestine.

  1. Characterization of a novel phosphorylation site in the sodium-chloride cotransporter, NCC

    Rosenbaek, L L; Assentoft, M; Pedersen, N B;

    2012-01-01

    The sodium-chloride cotransporter, NCC, is essential for renal electrolyte balance. NCC function can be modulated by protein phosphorylation. In this study, we characterized the role and physiological regulation of a novel phosphorylation site in NCC at Ser124 (S124). Novel phospho......DAVP significantly increased pS124-NCC abundance, with no changes in total NCC plasma membrane abundance. pS124-NCC levels also increased in abundance in rats after stimulation of the renin-angiotensin-aldosterone system by dietary low sodium intake. In contrast to other NCC phosphorylation sites, the STE20/SPS1...

  2. Sodium-glucose cotransporter-2 inhibition and the insulin: Glucagon ratio: Unexplored dimensions.

    Kalra, Sanjay; Gupta, Yashdeep; Patil, Shiva

    2015-01-01

    The sodium-glucose cotransporter 2 (SGLT-2) inhibitors are a novel class of glucose-lowering drugs which act by inhibiting the reabsorption of filtered glucose from the kidneys. Their effect on insulin and glucagon levels has recently been studied but is not fully explained. This communication proposes various hypotheses: A direct effect of SGLT-2 inhibition on the alpha cell receptors, a paracrine or intra-islet mediated effect on alpha cell sensitivity to glucose, and a calorie restriction mimetic action, to explain the impact of these drugs on the insulin glucagon ratio. PMID:25932403

  3. Sodium-glucose cotransporter-2 inhibition and the insulin: Glucagon ratio: Unexplored dimensions

    Sanjay Kalra

    2015-01-01

    Full Text Available The sodium-glucose cotransporter 2 (SGLT-2 inhibitors are a novel class of glucose-lowering drugs which act by inhibiting the reabsorption of filtered glucose from the kidneys. Their effect on insulin and glucagon levels has recently been studied but is not fully explained. This communication proposes various hypotheses: A direct effect of SGLT-2 inhibition on the alpha cell receptors, a paracrine or intra-islet mediated effect on alpha cell sensitivity to glucose, and a calorie restriction mimetic action, to explain the impact of these drugs on the insulin glucagon ratio.

  4. Glucose transport by human renal Na+/d-glucose cotransporters SGLT1 and SGLT2

    Hummel, Charles S.; Lu, Chuan; Loo, Donald D. F.; Hirayama, Bruce A.; Voss, Andrew A.; Wright, Ernest M.

    2010-01-01

    The human Na+/d-glucose cotransporter 2 (hSGLT2) is believed to be responsible for the bulk of glucose reabsorption in the kidney proximal convoluted tubule. Since blocking reabsorption increases urinary glucose excretion, hSGLT2 has become a novel drug target for Type 2 diabetes treatment. Glucose transport by hSGLT2 was studied at 37°C in human embryonic kidney 293T cells using whole cell patch-clamp electrophysiology. We compared hSGLT2 with hSGLT1, the transporter in the straight proximal...

  5. Electrochemical deposition of carbon films on titanium in molten LiCl-KCl-K{sub 2}CO{sub 3}

    Song, Qiushi; Xu, Qian, E-mail: Qianxu201@mail.neu.edu.cn; Wang, Yang; Shang, Xujing; Li, Zaiyuan

    2012-09-30

    Electrodeposition of carbon films on the oxide-scale-coated titanium has been performed in a LiCl-KCl-K{sub 2}CO{sub 3} melt, which are characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction analysis. The electrochemical process of carbon deposition is investigated by cyclic voltammetry on the graphite, titanium and oxide-scale-coated titanium electrodes. The particle-size-gradient carbon films over the oxide-scale-coated titanium can be achieved by electrodeposition under the controlled potentials for avoiding codeposition of lithium carbide. The deposited carbon films are comprised of micron-sized 'quasi-spherical' carbon particles with graphitized and amorphous phases. The cyclic voltammetry behavior on the graphite, titanium and oxide-scale-coated titanium electrodes shows that CO{sub 3}{sup 2-} ions are reduced most favorably on the graphite for the three electrodes. Lithium ions can discharge under the less negative potential on the electrode containing carbon compared with titanium electrode because of the formation of lithium carbide from the reaction between lithium and carbon. - Highlights: Black-Right-Pointing-Pointer Carbon films are prepared on oxide-scale-coated titanium in a LiCl-KCl-K{sub 2}CO{sub 3} melt. Black-Right-Pointing-Pointer The films comprise micron-size 'quasi-spherical' carbon particles. Black-Right-Pointing-Pointer The films present particle-size-gradient. Black-Right-Pointing-Pointer The particles contain graphitized and amorphous phases. Black-Right-Pointing-Pointer The prepared carbon films are more electrochemically active than graphite.

  6. Early increasing-intensity treadmill exercise reduces neuropathic pain by preventing nociceptor collateral sprouting and disruption of chloride cotransporters homeostasis after peripheral nerve injury.

    López-Álvarez, Víctor M; Modol, Laura; Navarro, Xavier; Cobianchi, Stefano

    2015-09-01

    Activity treatments, such as treadmill exercise, are used to improve functional recovery after nerve injury, parallel to an increase in neurotrophin levels. However, despite their role in neuronal survival and regeneration, neurotrophins may cause neuronal hyperexcitability that triggers neuropathic pain. In this work, we demonstrate that an early increasing-intensity treadmill exercise (iTR), performed during the first week (iTR1) or during the first 2 weeks (iTR2) after section and suture repair of the rat sciatic nerve, significantly reduced the hyperalgesia developing rapidly in the saphenous nerve territory and later in the sciatic nerve territory after regeneration. Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) expression in sensory neurons and spinal cord was reduced in parallel. iTR prevented the extension of collateral sprouts of saphenous nociceptive calcitonin gene-related peptide fibers within the adjacent denervated skin and reduced NGF expression in the same skin and in the L3 dorsal root ganglia (DRG). Injury also induced Na⁺-K⁺-2Cl⁻ cotransporter 1 (NKCC1) upregulation in DRG, and K⁺-Cl⁻ cotransporter 2 (KCC2) downregulation in lumbar spinal cord dorsal horn. iTR normalized NKCC1 and boosted KCC2 expression, together with a significant reduction of microgliosis in L3-L5 dorsal horn, and a reduction of BDNF expression in microglia at 1 to 2 weeks postinjury. These data demonstrate that specific activity protocols, such as iTR, can modulate neurotrophins expression after peripheral nerve injury and prevent neuropathic pain by blocking early mechanisms of sensitization such as collateral sprouting and NKCC1/KCC2 disregulation. PMID:26090759

  7. Electrical measurements on multiphased (NaCl){sub x}(KCl){sub y-x}(KBr){sub 1-y} single crystals

    Mahadevan, C.K. [Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, Tamil Nadu (India)], E-mail: mahad@sancharnet.in; Jayakumari, K. [Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, Tamil Nadu (India)

    2008-11-30

    Alkali halide mixed crystals were melt grown from NaCl, KCl and KBr starting materials. DC and AC electrical measurements were carried out on the resulting ternary compositions at temperatures ranging from 308 to 423 K. Activation energies and mean jump frequencies were also estimated. The present study indicates an increase of DC and AC electrical conductivities and dielectric constant with the increase of temperature. Also, it indicates a nonlinear variation of all the electrical parameters (both DC and AC) with the bulk composition, which is explained to be due to the enhanced diffusion of charge carriers along dislocations and grain boundaries.

  8. The extraction of nitrogen with a KCl solution and the supply of nitrogen to plants in 40 tropical soils

    The determination of the total nitrogen contents in KCl N extracts obtained from 40 tropical soil samples gave an extremely good indication of the aptitude of such soils to provide nitrogen for a plant in pot culture tests. N 15 isotopes were used to show that the levels of enrichment for the total nitrogen of the KCl extract were the same as those of the plant. This indicates that the soluble mineral and organic forms of nitrogen in KCl are an easily usable source of nitrogen for plants in tropical soils

  9. Regulation of plasma membrane localization of the Na+-taurocholate cotransporting polypeptide (Ntcp) by hyperosmolarity and tauroursodeoxycholate.

    Sommerfeld, Annika; Mayer, Patrick G K; Cantore, Miriam; Häussinger, Dieter

    2015-10-01

    In perfused rat liver, hepatocyte shrinkage induces a Fyn-dependent retrieval of the bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2) from the canalicular membrane (Cantore, M., Reinehr, R., Sommerfeld, A., Becker, M., and Häussinger, D. (2011) J. Biol. Chem. 286, 45014-45029) leading to cholestasis. However little is known about the effects of hyperosmolarity on short term regulation of the Na(+)-taurocholate cotransporting polypeptide (Ntcp), the major bile salt uptake system at the sinusoidal membrane of hepatocytes. The aim of this study was to analyze hyperosmotic Ntcp regulation and the underlying signaling events. Hyperosmolarity induced a significant retrieval of Ntcp from the basolateral membrane, which was accompanied by an activating phosphorylation of the Src kinases Fyn and Yes but not of c-Src. Hyperosmotic internalization of Ntcp was sensitive to SU6656 and PP-2, suggesting that Fyn mediates Ntcp retrieval from the basolateral membrane. Hyperosmotic internalization of Ntcp was also found in livers from wild-type mice but not in p47(phox) knock-out mice. Tauroursodeoxycholate (TUDC) and cAMP reversed hyperosmolarity-induced Fyn activation and triggered re-insertion of the hyperosmotically retrieved Ntcp into the membrane. This was associated with dephosphorylation of the Ntcp on serine residues. Insertion of Ntcp by TUDC was sensitive to the integrin inhibitory hexapeptide GRGDSP and inhibition of protein kinase A. TUDC also reversed the hyperosmolarity-induced retrieval of bile salt export pump from the canalicular membrane. These findings suggest a coordinated and oxidative stress- and Fyn-dependent retrieval of sinusoidal and canalicular bile salt transport systems from the corresponding membranes. Ntcp insertion was also identified as a novel target of β1-integrin-dependent TUDC action, which is frequently used in the treatment of cholestatic liver disease. PMID:26306036

  10. Intestinal Sodium Glucose Cotransporter 1 Inhibition Enhances Glucagon-Like Peptide-1 Secretion in Normal and Diabetic Rodents.

    Oguma, Takahiro; Nakayama, Keiko; Kuriyama, Chiaki; Matsushita, Yasuaki; Yoshida, Kumiko; Hikida, Kumiko; Obokata, Naoyuki; Tsuda-Tsukimoto, Minoru; Saito, Akira; Arakawa, Kenji; Ueta, Kiichiro; Shiotani, Masaharu

    2015-09-01

    The sodium glucose cotransporter (SGLT) 1 plays a major role in glucose absorption and incretin hormone release in the gastrointestinal tract; however, the impact of SGLT1 inhibition on plasma glucagon-like peptide-1 (GLP-1) levels in vivo is controversial. We analyzed the effects of SGLT1 inhibitors on GLP-1 secretion in normoglycemic and hyperglycemic rodents using phloridzin, CGMI [3-(4-cyclopropylphenylmethyl)-1-(β-d-glucopyranosyl)-4-methylindole], and canagliflozin. These compounds are SGLT2 inhibitors with moderate SGLT1 inhibitory activity, and their IC50 values against rat SGLT1 and mouse SGLT1 were 609 and 760 nM for phloridzin, 39.4 and 41.5 nM for CGMI, and 555 and 613 nM for canagliflozin, respectively. Oral administration of these inhibitors markedly enhanced and prolonged the glucose-induced plasma active GLP-1 (aGLP-1) increase in combination treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP4) inhibitor, in normoglycemic mice and rats. CGMI, the most potent SGLT1 inhibitor among them, enhanced glucose-induced, but not fat-induced, plasma aGLP-1 increase at a lower dose compared with canagliflozin. Both CGMI and canagliflozin delayed intestinal glucose absorption after oral administration in normoglycemic rats. The combined treatment of canagliflozin and a DPP4 inhibitor increased plasma aGLP-1 levels and improved glucose tolerance compared with single treatment in both 8- and 13-week-old Zucker diabetic fatty rats. These results suggest that transient inhibition of intestinal SGLT1 promotes GLP-1 secretion by delaying glucose absorption and that concomitant inhibition of intestinal SGLT1 and DPP4 is a novel therapeutic option for glycemic control in type 2 diabetes mellitus. PMID:26105952

  11. Preparation and dielectric properties of oxide added NaCl-KCl polycrystals

    Priya, M. [Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, Tamilnadu (India); Mahadevan, C.K. [Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, Tamilnadu (India)], E-mail: mahadevan58@yahoo.co.in

    2008-01-01

    Pure and ZnO and CdO added (separately) polycrystals of NaCl, KCl and (NaCl){sub 0.5}(KCl){sub 0.5} were prepared by the melt method. Density, atomic absorption spectroscopic and X-ray diffraction measurements indicate that the ZnO and CdO have entered into the lattices of alkali halide crystals. The dielectric measurements indicate that the dielectric parameters increase with the increase in temperature. Also, the dielectric constant and dielectric loss factor values decreased whereas the electrical conductivities increased with the increase in frequency of the AC applied. Significant changes have been observed with the dielectric parameters caused by ZnO and CdO additions. Also, the depth profile study was carried out on CdO added crystals which indicates that the dopant addition creates different layers along the crystal with increase of dopant content from top to bottom.

  12. Microstructural investigations of pure nickel exposed to KCl induced high temperature corrosion

    Jonsson, T.; Slomian, A.; Lomholt, Trine Nybo;

    2015-01-01

    Oxidation of 99?99% pure nickel was studied with and without 0?10 mg cm22 KCl(s) in an environment containing 5 vol.-%O2, 40 vol.-%H2O and 55 vol.-%N2 at 600uC for up to 168 h. Oxide microstructure was investigated by X-ray diffraction (XRD), focused ion beam (FIB), broad ion beam (BIB) and SEM....../EDX. Oxidised nickel shows an approximately parabolic oxide growth rate. The oxide scale is dense with some pores at the oxide/metal interface. Adding small amounts of KCl does not result in a faster corrosion rate of nickel. However, the surface morphology changes and small oxide crusts were observed in the...

  13. Short-pulse CO2-laser damage studies of NaCl and KCl windows

    The damage resistance of bare surfaces and the bulk interior of NaCl and KCl windows was measured with a short-pulse CO2 laser at 10.6 μm. Parametric studies with 1.7-ns pulses indicated that adsorbed water was probably the limiting agent on surface thresholds in agreement with previous studies at long pulsewidths. Rear-surface thresholds up to 7 J/cm2 were measured for polished NaCl windows, whereas KCl surfaces damaged at approximately 60% of this level. The breakdown electric-field thresholds of exit surfaces were only 50% of the value of the bulk materials. The pulsewidth dependence of surface damage from 1 to 65 ns, in terms of incident laser fluence, increased as t/sup 1/3/

  14. Gamma coloration of mixed crystals of KCl-KBr doped with Pb2+

    The influence of impurities of Pb2+ on the coloration curve under gamma irradiation, of five single mixed crystals of KCl1-xBrx, has been investigated. Also the impact of the dose rate, and the mixture proportions of the halides in the single crystals was examined. The appearance of F centers for a dose rate of 12.88 kGy/h, was independent of the quantity of Pb2+ , and varied according to the ratio KCl/KBr. At a proportion of 50% of each halogen the typical stages were observed. Meanwhile, if the dose rate is lower (3.22 kGy/h), the coloration depends of the quantity of Pb2+ . This dependence is maintained through out all halide proportions in the mixture. The behavior observed in these crystals is in agreement with the trap model for complementary defects F-centers. (author)

  15. SKELETAL MUSCLE SODIUM GLUCOSE CO-TRANSPORTERS IN OLDER ADULTS WITH TYPE 2 DIABETES UNDERGOING RESISTANCE TRAINING

    We examined the expression of the sodium-dependent glucose co-transporter system (SGLT3) in skeletal muscle of Hispanic older adults with type 2 diabetes. Subjects (65+/-8 yr) were randomized to resistance training (3x/wk, n=13) or standard of care (controls, n=5) for 16 weeks. Skeletal muscle SGL...

  16. Contribution to knowledge of radiation damage in KCl crystals doped with Sr

    The radiation damages in KCl crystals doped with Sr++ using thermo-ionic technique (ITC) and optical absorption measurements were studied. The variation of the entropy for the dipole jump starting from results reported by several authors was calculated. The irradiation effects with three different exposures were analysed: irradiation with gamma rays; irradiation with fast neutrons added to gamma irradiation; and irradiation with thermal neutrons together with fast neutrons and gamma rays. (Author)

  17. Optical absorption spectra of mercury centres in KCl and NaCl

    Optical absorption spectra of KCl and NaCl monocrystals doped with Hg2Cl2 were recorded at room temperature before and after 60Co #betta#-irradiation and F-light bleaching. It is concluded that gamma irradiation produces all types of Hg centres, that the Hg0 centres grow linearly with time of F-light bleaching, and that F-light bleaching enhances all the bands due to Hg centres

  18. Kinetics of ray bleaching of KCl crystal with Fsub(A)(Li)-centers

    Bleaching kinetics of KCl cubic crystal with Fsub(A) (Li) centers in the two-ray excitation mode was investigated theoretically and experimentally. Possibility for using a similar system as optical lock as well as optical pulse modulator is shown. Different modes of optical system operation were investigated, time characteristics of impurity crystal bleaching were studied in a wide range of exciting ray intensities

  19. Electrode potentials of uranium in the LiCl-KCl-CsCl eutectic melt

    Maltsev, D. S.; Volkovich, V. A.; Vladykin, E. N.; Vasin, B. D.

    2015-08-01

    The electrode potentials of uranium in the melt of the eutectic mixture of lithium, potassium, and cesium chlorides are measured in the temperature range 573-1073 K. Formal standard potentials E U * (III)/U and the main thermodynamic characteristics of uranium trichloride in the LiCl-KCl-CsCl melt are calculated, and the electronic absorption spectra of UCl 6 3- ions are measured.

  20. Integrated Data Collection Analysis (IDCA) Program - KClO3/Dodecane Mixture

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorenson, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-05-23

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small-Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO3 and dodecane—KClO3/dodecane mixture. This material was selected because of the challenge of performing SSST testing of a mixture of solid and liquid materials. The mixture was found to: 1) be more sensitive to impact than RDX, and PETN, 2) less sensitive to friction than PETN, and 3) less sensitive to spark than RDX. The thermal analysis showed little or no exothermic features suggesting that the dodecane volatilized at low temperatures. A prominent endothermic feature was observed assigned to melting of KClO3. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO3/dodecane mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), and Indian Head Division, Naval Surface Warfare Center, (NSWC IHD). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand

  1. ESR of an O/sub 3//sup -/ centre in KCl

    Callens, F.; Matthys, P.; Boesman, E.

    1988-06-20

    By means of ESR an ozonide molecular O/sub 3//sup -/ ion was detected in x-irradiated KCl. The principal values of the G-tensor (2.0032, 2.0182, 2.0118) are in excellent agreement with the values found in other host lattices and with CNDO calculations performed earlier. All measurements were carried out at liquid-helium temperatures.

  2. X-ray storage performance of KCl:Eu2+ with high cumulated dose

    Hansel, Rachael A.; Xiao, Zhiyan; Zhang, Lei; Li, H. Harold

    2014-05-01

    The effects of high cumulative radiation dose on the luminescence properties of KCl:Eu2+ are investigated. Pellet samples of KCl:Eu2+ were given doses of up to 200 kGy at the Louisiana State University Synchrotron facility. After synchrotron irradiation, samples were optically bleached and given a clinical dose of 2 Gy from a 6 MV medical linear accelerator. Optical properties were evaluated using photostimulated luminescence (PSL), photoluminescence (PL), and temperature-dependent PSL measurements. For a cumulated dose of up to 5-10 kGy, the PSL emission intensity increased by 15% compared to the PSL signal with no radiation history. For doses higher than 10 kGy, the PSL emission intensity retained at least 70% of the original intensity. Spatial correlation of the charge storage centers increased for doses up to 5 kGy and then decreased for higher cumulative doses. Emission band at 975 nm was attributed to transitions of Eu1+. PL spectra showed an intense peak centered at 420 nm for all cumulative doses. The results of this work show that KCl:Eu2+ storage phosphors are excellent reusable materials for radiation therapy dosimetry.

  3. Potential Process for the Decontamination of Pyro-electrometallurgical LiCl-KCl Eutectic Salt Electrolyte

    Presented here is a potential option with experimental validation for the decontamination of LiCl-KCl eutectic salt electrolyte from a pyro-electrometallurgical process by employing already developed inorganic ion exchange materials. Adsorbent materials considered include titano-silicates and molybdo- and tungstophosphates for Cs extraction, Si-doped antimony pyrochlore for Sr extraction and hexagonal tungsten bronzes for lanthanide (LN) and minor actinide (MA) polishing. Encouraging results from recent investigations on the removal of target elements (Cs, Sr and LN) from aqueous solutions containing varying concentrations of alkali and alkali metal contaminants which would be akin to a solution formed from the dissolution of spent LiCl-KCl eutectic salt electrolyte are presented. Further investigations have also shown that the saturated adsorbents can be treated at relatively low temperatures to afford potential waste forms for the adsorbed elements. Efficient evaporation and drying of a solution of dissolved LiCl-KCl eutectic salt electrolyte (50 L, 5 L.h-1) has been demonstrated using a Microwave-Heated Mechanical Fluidized Bed (MWMFB) apparatus. (authors)

  4. High-Temperature Viscosity Measurement of LiCl-KCl Molten Salts Comprising Actinides and Lanthanides

    Kim, Jongyun; Bae, Sangeun; Kim, Daehyun; Choi, Yong Suk; Yeon, Jeiwon; Song, Kyuseok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-11-15

    Physical properties of molten salt such as viscosity, density, solubility, surface tension, solubility, diffusivity, electrical/thermal conductivity, etc., are important for the design and the early fault detection of each unit processes in the pyroprocess. Among them, the viscosities of the high-temperature molten salts should be considered much more carefully when designing the plant as well as handling and transferring the molten fluid containing radioactive actinides and lanthanides from one unit process to the other in the pyroprocess. The viscosity is also related to the electrical properties and the structure of the liquids. However, there are only viscosity data of pure molten LiCl-KCl eutectic in a limited range of temperatures (890-1080 K). Therefore, interpolation and extrapolation are required to determine the viscosity at a specific process condition, for example, at ca. 773 K for the transfer of molten salt in the pyroprocess. In addition, there have been no previous reports on the viscosity of LiCl-KCl eutectic containing a wide concentration range of actinides and lanthanides such as uranium (U), neodymium (Nd), cerium (Ce), and lanthanum (La), which are of major interests regarding the recycling of LiCl-KCl molten salts.

  5. CFD Investigation on Free Surface of Immiscible Molten LiCl-KCl/Cd System

    Kim, Kwangrag; Kim, Sihyung; Shim, Junbo; Park, Seungwoo; Kim, Intae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    LiCl-KCl eutectic serves as an electrolyte, and liquid cadmium serves as a cathode material. Therefore, the electrowinning reactors need to be designed to provide high mass transfer and electrode surface area between the electrode and bulk electrolyte. The efficiency of the electrowinning cell is largely affected by its geometric configuration and electrolyte turbulence. The influence of electrolyte flow on the performance can be evaluated using a CFD model. However, the hydrodynamic behavior in the molten state is not well understood in this system. Therefore, a computational method has been developed to investigate the hydrodynamic behavior of immiscible phases in an electrowinning cell. This paper presents an interface tracking method for modeling the flow of immiscible liquids of LiCl-KCl/Cd in the electrolytic processes. An approach was proposed to provide an insight into the behaviors of free electrode surface in an electrowinning cell. A numerical model has been developed to simulate complex free surface flows in an immiscible molten LiCl-KCl/Cd system. It was found that this method was capable of tracking a contorting free surface as well as interface mass transfer in the multi-phase flow fields. The approach can provide an insight into the behaviors of free electrode surface in an electrowinning cell.

  6. Release of mercury halides from KCl denuders in the presence of ozone

    S. N. Lyman

    2010-09-01

    Full Text Available KCl-coated denuders have become a standard method for measurement of gaseous oxidized mercury, but their performance has not been exhaustively evaluated, especially in field conditions. In this study, KCl-coated and uncoated quartz denuders loaded with HgCl2 and HgBr2 lost 29–55% of these compounds, apparently as elemental mercury, when exposed to ozone (range of 6–100 ppb tested. This effect was also observed for denuders loaded with gaseous oxidized mercury at a field site in Nevada (3–37% of oxidized mercury lost. In addition, collection efficiency decreased by 12–30% for denuders exposed to 50 ppb ozone during collection of HgCl2. While data presented were obtained from laboratory tests and as such do not exactly simulate field sampling conditions, these results indicate that the KCl denuder oxidized mercury collection method may not be as robust as previously thought. This work highlights needs for further testing of this method, clear identification of gaseous oxidized mercury compounds in the atmosphere, and development of field calibration methods for these compounds.

  7. Potential Process for the Decontamination of Pyro-electrometallurgical LiCl-KCl Eutectic Salt Electrolyte

    Griffith, Christopher S.; Sizgek, Erden; Sizgek, Devlet; Luca, Vittorio [Australian Nuclear Science and Technology Organisation (ANSTO), Institute of Materials Engineering, New Illawarra Road, Lucas Heights, New South Wales, 2234 (Australia)

    2008-07-01

    Presented here is a potential option with experimental validation for the decontamination of LiCl-KCl eutectic salt electrolyte from a pyro-electrometallurgical process by employing already developed inorganic ion exchange materials. Adsorbent materials considered include titano-silicates and molybdo- and tungstophosphates for Cs extraction, Si-doped antimony pyrochlore for Sr extraction and hexagonal tungsten bronzes for lanthanide (LN) and minor actinide (MA) polishing. Encouraging results from recent investigations on the removal of target elements (Cs, Sr and LN) from aqueous solutions containing varying concentrations of alkali and alkali metal contaminants which would be akin to a solution formed from the dissolution of spent LiCl-KCl eutectic salt electrolyte are presented. Further investigations have also shown that the saturated adsorbents can be treated at relatively low temperatures to afford potential waste forms for the adsorbed elements. Efficient evaporation and drying of a solution of dissolved LiCl-KCl eutectic salt electrolyte (50 L, 5 L.h{sup -1}) has been demonstrated using a Microwave-Heated Mechanical Fluidized Bed (MWMFB) apparatus. (authors)

  8. Evaporation Behaviors of Rare Earth Chlorides in LiCl-KCl Eutectic salt

    Electrorefining process is one of the important processes of a pyro-process. In the electrorefining process, uranium metal is deposited at the solid cathode as dendritic form. Uranium deposits from an electrorefining process contain about 30 wt% of salts. In order to recover pure metal and convert it into metal ingots, the salt has to be removed. In the salt, there are actinide chlorides and rare earth chlorides in addition to uranium chloride. In order to design the salt evaporation system, it should be investigated the evaporation behaviors of actinide and rare earth chlorides in the salt. In this work, the experiments for a salt evaporation of rare earth chlorides in LiCl-KCl eutectic salt were carried out with a salt distiller with respect to the vacuum pressure and the hold temperature. The vapor pressure of rare earth chlorides are lower than those of LiCl and KCl. But the rare earth chlorides were co-evaporized with LiCl-KCl salt during the salt evaporation process. A simple model based on the Hertz-Langmuir relation was applied for this evaporation system and the co-evaporation of rare earth chlorides was discussed. (authors)

  9. Supercooling of aqueous NaCl and KCl solutions under acoustic levitation.

    Lü, Y J; Wei, B

    2006-10-14

    The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions. PMID:17042605

  10. On the electrochemical formation of Pu-Al alloys in molten LiCl-KCl

    Mendes, E.; Malmbeck, R.; Nourry, C.; Souček, P.; Glatz, J.-P.

    2012-01-01

    Properties of Pu-Al alloys were investigated in connection with development of pyrochemical methods for reprocessing of spent nuclear fuel. Electroseparation techniques in molten LiCl-KCl are being developed in ITU to group-selectively recover actinides from the mixture with fission products. In the process, actinides are electrochemically reduced on solid aluminium cathodes, forming solid actinide-aluminium alloys. This article is focused on electro-chemical characterisation of Pu-Al alloys in molten LiCl-KCl, on electrodeposition of Pu on solid Al electrodes and on determination of chemical composition and structure of the formed alloys. Cyclic voltammetry and chronopotentiometry were used to study Pu-Al alloys in the temperature range 400-550 °C. Pu is reduced to metal in one reduction step Pu 3+/Pu 0 on an inert W electrode. On a reactive Al electrode, the reduction of Pu 3+ to Pu 0 occurs at a more positive potential due to formation of Pu-Al alloys. The open circuit potential technique was used to identify the alloys formed. Stable deposits were obtained by potentiostatic electrolyses of LiCl-KCl-PuCl 3 melts on Al plates. XRD and SEM-EDX analyses were used to characterise the alloys, which were composed mainly of PuAl 4 with some PuAl 3. In addition, the preparation of PuCl 3 containing salt by carbochlorination of PuO 2 is described.

  11. Effect of x-ray irradiation on thermal expansion of KCl single crystals

    The apparatus designed and fabricated earlier for accurate measurement of changes in length of solids through changes in capacitance of a condenser has been improved considerably to step up the accuracy of measurement to 10sup(-6) cm. Using this set-up, the thermal expansion of KCl single crystals before and after X-ray irradiation has been studied. It is found that the linear thermal expansion co-efficient (α) of X-ray irradiated KCl crystal increases to 47 x 10sup(-6)/deg C around room temperature, but attains the α value of unirradiated sample (39.8 x 10sup(-6)/deg C) in the temperature range 125deg C to 200deg C. From these data the number of vacancies created in KCl at room temperature by X-ray irradiation is calculated to be 9 x 10sup(17)/c.c. which is in fairly good agreement with the value 6 x 10sup(17)/c.c. calculated from optical absorption measurements taken on the same sample in the laboratory. (auth.)

  12. Water transport by Na+-coupled cotransporters of glucose (SGLT1) and of iodide (NIS). The dependence of substrate size studied at high resolution

    Zeuthen, Thomas; Belhage, Bo; Zeuthen, Emil

    2005-01-01

    previous investigations. The rate of cotransport was monitored as the clamp current obtained from two-electrode voltage clamp. The high resolution data demonstrated a fixed ratio between the turn-over of the cotransporter and the rate of water transport. This applied to experiments in which the rate of...... and osmosis at the membrane with diffusion in the cytoplasm. The combination of high resolution measurements and precise modelling showed that water transport across the membrane can be explained by cotransport of water in the membrane proteins and that intracellular unstirred layers effects are...

  13. Acidity of cations and the solubility of oxides in the eutectic KCl-LiCl melt at 700 Deg C

    Products of MgO, NiO and CoO solubility in KCl-LiCl melt at 700 Deg C were determined by the method of potentiometric titration using Pt(O2)IZrO2(Y2O3) membrane oxygen electrode. It was ascertained that acid properties of Cd2+ and Pb'2+ cations are levelled to Li+ properties, a break in E-pO graduation dependence in KCl-LiCl melt was observed at pO ∼ 2. Increase in oxides solubility in the melt studied compared with KCl-NaCl and CsCl-KCl-NaCl melts stems from the presence of Li+ cations in the melt studied, which possess stronger acid properties than those of Na+ or K+

  14. Strategies to reduce gaseous KCl and chlorine in deposits during combustion of biomass in fluidised bed boilers

    Kassman, Haakan

    2012-11-01

    Combustion of a biomass with an enhanced content of alkali and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. The strategies applied to reduce such problems include co-combustion and the use of additives. In this work, measures were investigated in order to decrease the risk of superheater corrosion by reducing gaseous KCl and the content of chlorine in deposits. The strategies applied were sulphation of KCl by sulphur/sulphate containing additives (i.e. elemental sulphur (S) and ammonium sulphate (AS)) and co-combustion with peat. Both sulphation of KCl and capture of potassium (K) in ash components can be of importance when peat is used. The experiments were mainly performed in a 12 MW circulation fluidised bed (CFB) boiler equipped for research purposes but also in a full-scale CFB boiler. The results were evaluated by means of IACM (on-line measurements of gaseous KCl), conventional gas analysis, deposit and corrosion probe measurements and ash analysis. Ammonium sulphate performed significantly better than elemental sulphur. Thus the presence of SO{sub 3} (i.e. AS) is of greater importance than that of SO{sub 2} (i.e. S) for sulphation of gaseous KCl and reduction of chlorine in deposits. Only a minor reduction of gaseous KCl was obtained during co-combustion with peat although chlorine in the deposits was greatly reduced. This reduction was supposedly due to capture of K by reactive components from the peat ash in parallel to sulphation of KCl. These compounds remained unidentified. The effect of volatile combustibles on the sulphation of gaseous KCl was investigated. The poorest sulphation was attained during injection of ammonium sulphate in the upper part of the combustion chamber during the lowest air excess ratio. The explanation for this is that SO{sub 3} was partly consumed by side reactions due to the presence of combustibles. These experimental results were supported by modelling, although the

  15. Solubility of NaCl and KCl in aqueous HCl from 20 to 85°C

    Potter, Robert W., II; Clynne, Michael A.

    1980-01-01

    The solubilities of NaCl and KCl in aqueous HCl solutions were determined from 20 to 85°C at concentrations ranging from 0 to 20 g of HCl/100 g of solution. Equations are given that describe the solubilities over the range of conditions studied. For NaCl and KCl respectively measured solubilities show an average deviation from these equations of ??0.10 and ??0.08 g/100 g of saturated solution.

  16. Solubility polytherms of NaCl(KCl)-GdCl/sub 3/-H/sub 2/O system

    Shevchuk, V.G.; Lazorenko, N.M.; Storozhenko, D.A.; Kisel, N.N. (Poltavskij Inzhenerno-Stroitel' nyj Inst. (Ukrainian SSR))

    1982-04-01

    The isothermal method in the temperature range from 25 up to 100 deg C has been used to study the solubility in the NaCl-GdCl/sub 3/-H/sub 2/O and KCl-GdCl/sub 3/-H/sub 2/O systems. The limits of the NaCl, KCl and GdCl/sub 3/x6H/sub 2/O crystallization are discriminated. Solubility polytherms of the systems are plotted.

  17. Chrono-potentiometry in molten chlorides. Application to the study of the electrochemical properties of uranium and plutonium in the LiCl-KCl eutectic

    Using solutions of cadmium chloride in the eutectic LiCl-KCl, a chrono-potentiometric method has been developed with a view to its application to the study of molten solutions. Particular attention has been paid to the choice of the indicator electrodes. The method makes it possible to analyze molten solutions quantitatively and to determine diffusion coefficients and their activation energies; it yields furthermore information about the nature and the behaviour of ionic species in solution. The method has been applied to the study of solutions of uranium and plutonium chloride in the eutectic LiCl-KCl. Linear chrono-amperometry has been used for studying these solutions quantitatively, but chrono-potentiometry, of which the theory is better developed, is better suited to a quantitative study. The results obtained have made it possible to determine the diffusion coefficients of the ions Cd2+, U3+, U4+ and U(IV) in the presence of F- and Pu3+ ions, as well as the activation energy of the diffusion coefficients. (author)

  18. Ipragliflozin: A novel sodium-glucose cotransporter 2inhibitor developed in Japan

    Tsuyoshi Ohkura

    2015-01-01

    Sodium-glucose cotransporter 2 (SGLT2) inhibitioninduces glucosuria and decreases blood glucose levelsin diabetic patients and lowers hypoglycemic risk.SGLT1 is expressed in the kidney and intestine; SGLT1inhibition causes abdominal symptoms such as diarrheaand reduces incretin secretion. Therefore, SGLT2selectivity is important. Ipragliflozin is highly selectivefor SGLT2. In type 2 diabetes mellitus (T2DM), urinaryglucose excretion increased to 90 g/24 h after 28 d oftreatment with ipragliflozin 300 mg/d. Twelve weeksof ipragliflozin 50 mg/d vs placebo reduced glycatedhemoglobin and body weight by 0.65% and 0.66kg, respectively, in Western T2DM patients, and by1.3% and 1.89 kg, respectively, in Japanese patients.Ipragliflozin (highly selective SGLT2 inhibitor) improvesglycemic control and reduces body weight andlowers hypoglycemic risk and abdominal symptoms.Ipragliflozin can be a novel anti-diabetic and antiobesityagent.

  19. Compatibility of ZrN and HfN with molten LiCl-KCl-NaCl-UCl3

    The reaction kinetics of ZrN and HfN immersed in a quaternary salt of composition of 28.5% LiCl-36.3% KCl-29.4% NaCl-5.8% UCl3 (in weight percent) were assessed. Coupons of ZrN and HfN were exposed to the quaternary salt at 525-900 oC for 4-485 h. The reaction kinetics of the salt-refractory interactions were assessed through physical and microstructural characterization including scanning electron microscopy, X-ray diffraction and mass spectrometry. The results indicated that ZrN and HfN lose weight under all conditions investigated. While multiple mechanisms were evident, it is proposed that dissolution and oxidation were the dominant reactions that influence the weight loss. For the overall reaction, negative apparent activation energy values of -46 and -28 kJ/mol were observed in ZrN and HfN, respectively. These seemingly anomalous activation energies were associated with the simultaneous occurrence of electrochemical dissolution and surface oxide formation.

  20. Chrono-potentiometry in molten chlorides. Application to the study of the electrochemical properties of uranium and plutonium in the LiCl-KCl eutectic; Chronopotentiometrie dans les chlorures fondus. Application a l'etude des proprietes electrochimiques de l'uranium et du plutonium dans l'eutectique LiCl-KCl

    Leseur, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-05-01

    Using solutions of cadmium chloride in the eutectic LiCl-KCl, a chrono-potentiometric method has been developed with a view to its application to the study of molten solutions. Particular attention has been paid to the choice of the indicator electrodes. The method makes it possible to analyze molten solutions quantitatively and to determine diffusion coefficients and their activation energies; it yields furthermore information about the nature and the behaviour of ionic species in solution. The method has been applied to the study of solutions of uranium and plutonium chloride in the eutectic LiCl-KCl. Linear chrono-amperometry has been used for studying these solutions quantitatively, but chrono-potentiometry, of which the theory is better developed, is better suited to a quantitative study. The results obtained have made it possible to determine the diffusion coefficients of the ions Cd{sup 2+}, U{sup 3+}, U{sup 4+} and U(IV) in the presence of F{sup -} and Pu{sup 3+} ions, as well as the activation energy of the diffusion coefficients. (author) [French] La mise au point de la chronopotentiometrie comme moyen d'etude des solutions fondues a ete effectuee avec des solutions de chlorure de cadmium dans l'eutectique LiCl-KCl. Le probleme du choix des electrodes indicatrices a ete particulierement etudie. La methode permet l'analyse quantitative des solutions fondues ainsi que la determination des coefficients de diffusion et de leurs energies d'activation: elle donne en outre des renseignements sur la nature et le comportement des especes ioniques en solution. Elle a ete appliquee a l'etude des solutions des chlorures d'uranium et de plutonium dans l'eutectique LiCl-KCl. La chronoamperometrie lineaire a ete utilisee pour l'etude qualitative de ces solutions, mais la chronopotentiometrie, dont la theorie est plus complete, convient mieux pour l'etude quantitative. Les resultats obtenus ont permis de determiner les

  1. EPR of (LiH)+ and (AgH)+ centers in KCl

    Schwan, L.; Geigle, W.; Nagel, W; Bauer, R.; Stoll, H.

    1980-01-01

    In alkali halides hydrogen atoms can be stabilized near impurity cations, such as Li+ and Ag+, forming new centers which combine off-center substitutional Me+ and interstitial hydrogen H01 by a certain homeopolar binding. The analysis of EPR measurements in KCl yields the atomic configurations and shows that at T < 70 K the off-center tunneling motion of Me+ is quenched, while the high temperature spectra can be interpreted as time average of those at low temperature. The binding properties o...

  2. Studies on optical bleaching of x-ray irradiated KCL by thermoluminescence

    The optical bleaching characteristics of F-centres in X-ray irradiated KCl crystals have been studied by using thermoluminescence (TL) as the tool. It is found that the bleaching of F-centres takes place in two stages, a rapid stage initially, followed by a slow second age agreeing with reports of earlier workers based on photoconductivity and optical absorption measurements. SUDY OF THE BLEACHING CHARACTERISTICS OF THE INDIVIDUAL TL peaks shows that the individual TL peaks also follow a two-stage bleaching process. There is no correlation between the two stages of F-bleaching with those of formation of F-centres. (author)

  3. Oscillator strength of electronic color centers in KCl monocrystals irradiated by electrons and protons

    One studied absorption spectra of KCl single crystals irradiated by 15 and 100 keV energy and 5 x 1012-1015 cm-2 flow electrons and protons. In spectra one separated absorption elementary bands caused by coloring elementary (F-, Fα-, K-) and complex (M-, R2-, R4-, N-) centres. One determined correlation dependence of absorption coefficient of M-, R2-, R4-centres on absorption coefficient of F-centres and correlation dependence of absorption coefficient of R2-, R4-centres on coefficient of absorption of M-centres. One calculates the intensity of oscillators of M-, R2- and R4-centres of coloring

  4. An electrochemical study of uranium behaviour in LiCl-KCl-CsCl eutectic melt

    Maltsev, D. S.; Volkovich, V. A.; Vasin, B. D.; Vladykin, E. N.

    2015-12-01

    Electrochemical behaviour of uranium was studied in the low melting ternary LiCl-KCl-CsCl eutectic at 573-1073 K employing potentiometry, cyclic voltammetry and chronopotentiometry. Uranium electrode potentials were measured directly and U(III)/U(IV) red-ox potentials were determined from the results of cyclic voltammetry measurements. Formal standard electrode and red-ox potentials of uranium, and thermodynamic properties of uranium chlorides in the studied melt were calculated. Diffusion coefficients of U(III) and U(IV) ions were determined using cyclic voltammetry and chronopotentiometry.

  5. Electrochemical behavior of actinide ions in LiCl-KCl eutectic melts

    The electrodeposition and dissolution of uranium and plutonium in LiCl-KCl eutectic salt on tungsten and molybdenum working electrodes were investigated by cyclic voltammetry at 723, 773 and 823 K. It is suggested from the voltammograms that the electrodeposition and dissolution of U and Pu, U3+/U and Pu3+/Pu, may be quasi-reversible, while the redox reaction of U4+/U3+ is reversible. The adsorption and desorption peaks of U and Pu on W and Mo working electrodes, respectively, caused by underpotential deposition, were observed. (orig.)

  6. Respon pertumbuhan bibit kakao (Theobroma cacao L.) terhadap pemberian pupuk guano dan KCl

    Rajagukguk, Pispa

    2015-01-01

    Addition of Guano in Cultivation of Cacao Seedling is the one of step to use organic fertilizer that comes from animal feces in the world. For that purpose addition guano aims to increase growth of Cacao in Cultivation of Seedling. This research had been conducted at experimental field of Fakultas Pertanian USU in October 2013 - January 2014 using factorial randomized block design with two factor, i.e. addition dose of Guano (0, 75 , 150 , 225 g/polibag) and dose of KCl (0 , ...

  7. Saturated steams pressure of HfCl4-KCl molten mixtures

    A bellows null pressure gauge and the dynamic method were used to measure the total and partial pressures of saturated vapors of individual components of molten HfCl4-KCl mixtures, as a function of temperature (260 to 1000 deg C) and composition (1.9 to 64.3 mol.% HfCl4). Empirical equations expressing the relationship between pressure and temperature are presented. It is shown that in molten mixtures of hafnium tetrachloride with chlorides of alkaline metals its partial pressure dramatically increases when potassium chloride substitutes for cesium chloride

  8. Integrated Data Collection Analysis (IDCA) program--KClO4/Dodecane Mixture

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-05-11

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4 and dodecane—KClO4/dodecane mixture. This material was selected because of the challenge of performing SSST testing of a mixture of solid and liquid materials. The mixture was found to: 1) be less sensitive to impact than RDX, and PETN, 2) less sensitive to friction than RDX and PETN, and 3) less sensitive to spark than RDX and PETN. The thermal analysis showed little or no exothermic features suggesting that the dodecane volatilized at low temperatures. A prominent endothermic feature was observed and assigned to a phase transition of KClO4. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO4/dodecane mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some

  9. Solubilidade do SrO em NaCl-Kcl fundido a 727ºC

    Combes Richard Louis; Koeller Sérgio Luiz

    2000-01-01

    The solubility product value of SrO has been found to be equal to 10-4,2 (molality scale) in molten equimolar mixture of NaCl and KCl at 727ºC, using a potentiometric method involving a calcia stabilized zirconia membrane electrode. This value, which is in a logical agreement with other alkaline-earth oxide determined solubilities, is compared to those of 10-5,8, 10-3,0 and 10-3,08 (molality scale) found in the litterature 33, 22 and 5 years ago, respectively. Such discrepencies have called t...

  10. Co-Transport of Polycyclic Aromatic Hydrocarbons by Motile Microorganisms Leads to Enhanced Mass Transfer under Diffusive Conditions

    Gilbert, Dorthea; Jakobsen, Hans H.; Winding, Anne; Mayer, Philipp

    2014-01-01

    with hydrophobicity indicated PAH co-transport with the motile organisms. Fluorescence microscopy confirmed such transport. The effective diffusivity of T. pyriformis, determined by video imaging microscopy, was found to exceed molecular diffusivities of the PAHs up to four-fold. Cell-bound PAH...... fractions were determined to range from 28% (naphthalene) to 92% (pyrene). Motile microorganisms can therefore function as effective carriers for HOCs under diffusive conditions and might significantly enhance mobility and availability of HOCs....

  11. Phosphate and Vascular Calcification: Emerging Role of the Sodium-Dependent Phosphate Cotransporter PiT-1

    Lau, Wei Ling; Festing, Maria H; Giachelli, Cecilia M.

    2010-01-01

    Elevated serum phosphate is a risk factor for vascular calcification and cardiovascular events in kidney disease as well as in the general population. Elevated phosphate levels drive vascular calcification, in part, by regulating vascular smooth muscle cell (VSMC) gene expression, function, and fate. The type III sodium-dependent phosphate cotransporter, PiT-1, is necessary for phosphate-induced VSMC osteochondrogenic phenotype change and calcification, and has recently been shown to have une...

  12. Sodium Glucose Co-transporter Type 2 (SGLT2) Inhibitors: Targeting the Kidney to Improve Glycemic Control in Diabetes Mellitus

    Bays, Harold

    2013-01-01

    Although hyperglycemia is a key therapeutic focus in the management of patients with type 2 diabetes mellitus (T2DM), many patients experience sub-optimal glycemic control. Current glucose-lowering agents involve the targeting of various body organs. Sodium glucose co-transporter type 2 (SGLT2) inhibitors target the kidney, reduce renal glucose reabsorption, and increase urinary glucose elimination, thus lowering glucose blood levels. This review examines some of the key efficacy and safety d...

  13. Empagliflozin: a new sodium-glucose co-transporter 2 (SGLT2) inhibitor for the treatment of type 2 diabetes

    Neumiller, Joshua J.

    2014-01-01

    Type 2 diabetes is increasing in prevalence worldwide, and hyperglycemia is often poorly controlled despite a number of therapeutic options. Unlike previously available agents, sodium-glucose co-transporter 2 (SGLT2) inhibitors offer an insulin-independent mechanism for improving blood glucose levels, since they promote urinary glucose excretion (UGE) by inhibiting glucose reabsorption in the kidney. In addition to glucose control, SGLT2 inhibitors are associated with weight loss and blood pr...

  14. The sodium glucose cotransporter 2 inhibitor empagliflozin does not prolong QT interval in a thorough QT (TQT) study

    Ring, Arne; Brand, Tobias; Macha, Sreeraj; Breithaupt-Groegler, Kerstin; Simons, Gudrun; Walter, Beate; Woerle, Hans J.; Broedl, Uli C.

    2013-01-01

    Background Empagliflozin is a potent, selective sodium glucose cotransporter 2 (SGLT2) inhibitor in development as an oral antidiabetic treatment. This QT interval study assessed potential effects of empagliflozin on ventricular repolarisation and other electrocardiogram (ECG) parameters. Methods A randomised, placebo-controlled, single-dose, double-blind, five-period crossover study incorporating a novel double-placebo period design to reduce sample size, while maintaining full statistical p...

  15. Expression of keratin 19, Na-K-Cl cotransporter and estrogen receptor alpha in developing mammary glands of ewes

    M. Colitti

    2011-01-01

    Mammary gland remodelling is strictly related to intracellular signals and stem cell biology. Among the best candidates to identify the nature and development of mammary cells are cytokeratin 19 (CK19), the Na-K-Cl cotransporter (NKCC1) and receptor of estrogen alpha (ERα). In this study, we analyzed the expression of these genes in ewe mammary glands from prepubertal stage to involution. Using Real time PCR we showed that NKCC1 transcription was significantly down regulated during lactation ...

  16. Restricted Feeding Phase Shifts Clock Gene and Sodium Glucose Cotransporter 1 (SGLT1) Expression in Rats1–4

    Balakrishnan, Anita; Stearns, Adam T.; Ashley, Stanley W.; Tavakkolizadeh, Ali; Rhoads, David B.

    2010-01-01

    The intestine exhibits striking diurnal rhythmicity in glucose uptake, mediated by the sodium glucose cotransporter (SGLT1); however, regulatory pathways for these rhythms remain incompletely characterized. We hypothesized that SGLT1 rhythmicity is linked to the circadian clock. To investigate this, we examined rhythmicity of Sglt1 and individual clock genes in rats that consumed food ad libitum (AL). We further compared phase shifts of Sglt1 and clock genes in a second group of rats followin...

  17. New potential sodium-glucose co-transporters sugar-based inhibitors for the treatment of diabetes

    Jesus, Ana Rita Xavier de

    2015-01-01

    Tese de doutoramento, Química (Química Orgânica), Universidade de Lisboa, Faculdade de Ciências, 2015 A small library of C-glucosyl dihydrochalcones and their aglycones, chalcones and dihydrochalcones, were synthesized aiming at preparing new C-glucosyl analogues of phlorizin, a well-known non-selective sodium-glucose co-transporter inhibitor, bearing different substituents on the dihydrochalcone moiety. Chalcones were prepared by conventional aldol condensation methods and also by microwa...

  18. Sodium Glucose Cotransporter 2 (SGLT2) Plays as a Physiological Glucose Sensor and Regulates Cellular Contractility in Rat Mesangial Cells

    Masanori Wakisaka; Tetsuhiko Nagao; Mototaka Yoshinari

    2016-01-01

    Purpose Mesangial cells play an important role in regulating glomerular filtration by altering their cellular tone. We report the presence of a sodium glucose cotransporter (SGLT) in rat mesangial cells. This study in rat mesangial cells aimed to evaluate the expression and role of SGLT2. Methods The SGLT2 expression in rat mesangial cells was assessed by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR). Changes in the mesangial cell surface area at different gluc...

  19. Growth of NaCl on thin epitaxial KCl films on Ag(100) studied by SPA-LEED

    Marquardt, Christian; Paulheim, Alexander; Sokolowski, Moritz

    2015-11-01

    We investigated the growth of NaCl on thin (100)-oriented films of KCl by spot profile analysis of low energy electron diffraction (SPA-LEED). The underlying question of this investigation was how the system accommodates to the misfit of - 10% between the NaCl and KCl lattices. The KCl films (3 atomic layers thick) were epitaxially grown on a Ag(100) single crystal. We studied the heteroepitaxial growth of NaCl on KCl at 300 K and at 500 K, respectively. At 300 K, the first NaCl monolayer (ML) grows pseudomorphically on the KCl film. From the second layer onward, the NaCl lattice relaxes. The NaCl multilayers roughen, and a small rotational disorder (± 4°) of the NaCl domains is observed. The roughening results from the formation of multilayer islands of limited lateral size due to the misfit to the pseudomorphic first NaCl layer. At a growth temperature of 500 K, no pseudomorphic NaCl layer forms, instead relaxed multilayer island growth of NaCl is observed from the first layer onward. Similarly to the growth at 300 K, we find NaCl multilayer islands of limited lateral size. For both temperatures, we explain this growth behavior by the misfit that makes the adsorption sites at the island edges of the first relaxed NaCl layer less favorable for larger islands, promoting nucleation of multilayer islands.

  20. Functional interaction between CFTR and the sodium-phosphate co-transport type 2a in Xenopus laevis oocytes.

    Naziha Bakouh

    Full Text Available BACKGROUND: A growing number of proteins, including ion transporters, have been shown to interact with Cystic Fibrosis Transmembrane conductance Regulator (CFTR. CFTR is an epithelial chloride channel that is involved in Cystic Fibrosis (CF when mutated; thus a better knowledge of its functional interactome may help to understand the pathophysiology of this complex disease. In the present study, we investigated if CFTR and the sodium-phosphate co-transporter type 2a (NPT2a functionally interact after heterologous expression of both proteins in Xenopus laevis oocytes. METHODOLOGY/FINDINGS: NPT2a was expressed alone or in combination with CFTR in X. laevis oocytes. Using the two-electrode voltage-clamp technique, the inorganic phosphate-induced current (IPi was measured and taken as an index of NPT2a activity. The maximal IPi for NPT2a substrates was reduced when CFTR was co-expressed with NPT2a, suggesting a decrease in its expression at the oolemna. This was consistent with Western blot analysis showing reduced NPT2a plasma membrane expression in oocytes co-expressing both proteins, whereas NPT2a protein level in total cell lysate was the same in NPT2a- and NPT2a+CFTR-oocytes. In NPT2a+CFTR- but not in NPT2a-oocytes, IPi and NPT2a surface expression were increased upon PKA stimulation, whereas stimulation of Exchange Protein directly Activated by cAMP (EPAC had no effect. When NPT2a-oocytes were injected with NEG2, a short amino-acid sequence from the CFTR regulatory domain that regulates PKA-dependent CFTR trafficking to the plasma membrane, IPi values and NPT2a membrane expression were diminished, and could be enhanced by PKA stimulation, thereby mimicking the effects of CFTR co-expression. CONCLUSION/PERSPECTIVES: We conclude that when both CFTR and NPT2a are expressed in X. laevis oocytes, CFTR confers to NPT2a a cAMPi-dependent trafficking to the membrane. This functional interaction raises the hypothesis that CFTR may play a role in

  1. A simplified model of TiH1.65/KClO4 pyrotechnic ignition.

    Chen, Ken Shuang

    2009-04-01

    A simplified model was developed and is presented in this report for simulating thermal transport coupled with chemical reactions that lead to the pyrotechnic ignition of TiH1.65/KClO4 powder. The model takes into account Joule heating via a bridgewire, thermal contact resistance at the wire/powder interface, convective heat loss to the surroundings, and heat released from the TiH1.65- and KClO4-decomposition and TiO2-oxidation reactions. Chemical kinetic sub-models were put forth to describe the chemical reaction rate(s) and quantify the resultant heat release. The simplified model predicts pyrotechnic ignition when heat from the pyrotechnic reactions is accounted for. Effects of six key parameters on ignition were examined. It was found that the two reaction-rate parameters and the thermal contact resistance significantly affect the dynamic ignition process whereas the convective heat transfer coefficient essentially has no effect on the ignition time. Effects of the initial/ambient temperature and electrical current load through the wire are as expected. Ignition time increases as the initial/ambient temperature is lowered or the wire current load is reduced. Lastly, critical needs such as experiments to determine reaction-rate and other model-input parameters and to measure temperature profiles, time to ignition and burn-rate data for model validation as well as efforts in incorporating reaction-rate dependency on pressure are pointed out.

  2. Thermodynamics of neptunium in LiCl-KCl eutectic/liquid bismuth systems

    Thermodynamic properties of neptunium in LiCl-KCl eutectic/liquid bismuth systems in the temperature range 400--500 C have been studied using a galvanic cell method for the pyrometallurgical reprocessing of nuclear spent fuels. The standard potential of the Np/Np(III) couple vs. the Ag/AgCl (1 wt% AgCl) reference electrode in LiCl-KCl eutectic was measured and given by the equation ENp/Np(III)0 = minus2.0667 + 0.0007892 T (σ = 0.0009), where E is in volts, T is in kelvin, and σ is the standard deviation. The potential of neptunium-bismuth alloy, ENp-Bi, was measured as a function of neptunium concentration, XNpinBi. The curves for EBi-Np vs. log XNpinBi indicated the neptunium solubility in liquid bismuth to be 0.34 ± 0.02, 0.61 ± 0.08, and 1.06 ± 0.09 (±σ) atom % at 400, 450, and 500 C, respectively. The excess partial free energy of neptunium in liquid bismuth was represented by the equation, Δbar GNpxs (kcal/g atom) = minus32.5 (±0.7) + 0.0072 (±0.0010) T. The values of the solubility and excess partial free energy for neptunium were closer to those for plutonium rather than uranium

  3. Making a Pellet-type LiCl-KCl-UCl3 salt for Electrorefining

    Woo, M. S.; Jin, H. J.; Kim, I. T.; Kim, J. G. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The role of uranium chloride salt (UCl3) is to stabilize the initial cell voltage between electrodes in the electrorefining reactor. The process to produce a uranium chloride salt includes two steps: a reaction process of gaseous chlorine with liquid cadmium to form the CdCl2 occurring in a Cd layer, followed by a process to produce UCl3 by the reaction of U in the LiCl-KCl eutectic salt and CdCl2 The apparatus for producing UCl3 consists of a chlorine gas generator, a uranium chlorinator, a Cd distiller, the pelletizer, and a off-gas and a dry scrubber. The temperature of the reactants is maintained at about 600 .deg. C. After the reaction is completed in the uranium chlorinator, The salt products is transferred to the Cd distiller to decrease residual Cd concentration in the salts, and then salt is transferred to the mould of pelletizer by a transfer system to make pellet type salt. Making pellet type LiCl-KCl-UCl3 salt for electrorefining was carried out using the chlorinator, Cd distiller, and pelletizer. Salt transfer carried out by salt transfer equipment heated 500 .deg. C. The Cd concentration of final salt products distillated at 60 torr, 2 hrs, 600 .deg. C was 200 ppm from the ICP, XRD analysis. And pellet type salt products were fabricated by using the mould of pelletizer at 90∼130 .deg. C.

  4. LiCl-KCl Induced Corrosion of Copper at Low Temperature

    Structural materials for PRIDE system are stainless steel and copper mainly. And these are known for maintaining integrity when there is no oxygen and water. But physicochemical behavior of structural materials of PRIDE system when there is some of oxygen and water is lack of research. And when local corrosion is occurred, it can cause crack, so that it will be a big problem of safety and economic efficiency. So evaluation of thermodynamical and mechanical stabilities of structural materials for PRIDE system is necessary to predict lifetime of materials and time to replace the part of the equipment. There is no research of evaluation of long-term structural stability of structural materials for PRIDE system now. The present work investigates how LiCl-KCl molten salts influence the low temperature corrosion of copper. From the corrosion test, we can confirm that LiCl-KCl salt accelerates the corrosion of copper at low temperature. It was observed by surface analysis and gravimetry. The corrosion pattern is general corrosion and corrosion rate is increased as the temperature and time go up

  5. Method for making a Pellet-type LiCl-KCl-UCl3 SALT

    A pyrometallurgical partitioning technology to recover uranium from a uranium-TRU mixture which is the product material of electroreduction system is being developed at KAERI since 1997. In the process, the reactor of an electrorefiner consists of the electrodes and the molten chloride salt which is LiCl-KCl-UCl3. The role of uranium chloride salt (UCl3) is to stabilize the initial cell voltage between electrodes in the electrorefining reactor. The process to produce a uranium chloride salt includes two steps: a reaction process of gaseous chlorine with liquid cadmium to form CdCl2 occurring in a Cd layer, followed by a process to produce UCl3 by the reaction of U in the LiCl-KCl eutectic salt and CdCl2 The apparatus for producing UCl3 consists of a chlorine gas generator, a uranium chlorinator, a Cd distiller, the pelletizer, and a off-gas and a dry scrubber. The temperature of the reactants is maintained at about 600 .deg. C. After the reaction is completed in the uranium chlorinator, The salt products is transferred to the Cd distiller to decrease residual Cd concentration in the salts, and then salt is transferred to the mould of a pelletizer by a transfer system to make a pellet type salt

  6. LiCl-KCl Induced Corrosion of Copper at Low Temperature

    Lee, Jae-Hoon; Sim, Ji-Hyung; Kim, Yong-Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Structural materials for PRIDE system are stainless steel and copper mainly. And these are known for maintaining integrity when there is no oxygen and water. But physicochemical behavior of structural materials of PRIDE system when there is some of oxygen and water is lack of research. And when local corrosion is occurred, it can cause crack, so that it will be a big problem of safety and economic efficiency. So evaluation of thermodynamical and mechanical stabilities of structural materials for PRIDE system is necessary to predict lifetime of materials and time to replace the part of the equipment. There is no research of evaluation of long-term structural stability of structural materials for PRIDE system now. The present work investigates how LiCl-KCl molten salts influence the low temperature corrosion of copper. From the corrosion test, we can confirm that LiCl-KCl salt accelerates the corrosion of copper at low temperature. It was observed by surface analysis and gravimetry. The corrosion pattern is general corrosion and corrosion rate is increased as the temperature and time go up.

  7. Clinical potential of sodium-glucose cotransporter 2 inhibitors in the management of type 2 diabetes

    Kim Y

    2012-08-01

    Full Text Available Yoojin Kim, Ambika R BabuDivision of Endocrinology, John Stroger Jr Hospital of Cook County and Rush University, Chicago, IL, USABackground: The kidney plays an important role in glucose metabolism, and has been considered a target for therapeutic intervention. The sodium-glucose cotransporter type 2 (SGLT2 mediates most of the glucose reabsorption from the proximal renal tubule. Inhibition of SGLT2 leads to glucosuria and provides a unique mechanism to lower elevated blood glucose levels in diabetes. The purpose of this review is to explore the physiology of SGLT2 and discuss several SGLT2 inhibitors which have clinical data in patients with type 2 diabetes.Methods: We performed a PubMed search using the terms "SGLT2" and "SGLT2 inhibitor" through April 10, 2012. Published articles, press releases, and abstracts presented at national and international meetings were considered.Results: SGLT2 inhibitors correct a novel pathophysiological defect, have an insulin-independent action, are efficacious with glycosylated hemoglobin reduction ranging from 0.5% to 1.5%, promote weight loss, have a low incidence of hypoglycemia, complement the action of other antidiabetic agents, and can be used at any stage of diabetes. They are generally well tolerated. However, due to side effects, such as repeated urinary tract and genital infections, increased hematocrit, and decreased blood pressure, appropriate patient selection for drug initiation and close monitoring after initiation will be important. Results of ongoing clinical studies of the effect of SGLT2 inhibitors on diabetic complications and cardiovascular safety are crucial to determine the risk-benefit ratio. A recent decision by the Committee for Medicinal Products for Human Use of the European Medicines Agency has recommended approval of dapagliflozin for the treatment of type 2 diabetes as an adjunct to diet and exercise, in combination with other glucose-lowering medicinal products, including

  8. Potassium channel and NKCC cotransporter involvement in ocular refractive control mechanisms.

    Sheila G Crewther

    Full Text Available Myopia affects well over 30% of adult humans globally. However, the underlying physiological mechanism is little understood. This study tested the hypothesis that ocular growth and refractive compensation to optical defocus can be controlled by manipulation of potassium and chloride ion-driven transretinal fluid movements to the choroid. Chicks were raised with +/-10D or zero power optical defocus rendering the focal plane of the eye in front of, behind, or at the level of the retinal photoreceptors respectively. Intravitreal injections of barium chloride, a non-specific inhibitor of potassium channels in the retina and RPE or bumetanide, a selective inhibitor of the sodium-potassium-chloride cotransporter were made, targeting fluid control mechanisms. Comparison of refractive compensation to 5 mM Ba(2+ and 10(-5 M bumetanide compared with control saline injected eyes shows significant change for both positive and negative lens defocus for Ba(2+ but significant change only for negative lens defocus with bumetanide (Rx(SAL(-10D = -8.6 +/- .9 D; Rx(Ba2+(-10D = -2.9 +/- .9 D; Rx(Bum(-10D = -2.9 +/- .9 D; Rx(SAL(+10D = +8.2 +/- .9 D; Rx(Ba2+(+10D = +2.8 +/- 1.3 D; Rx(Bum(+10D = +8.0 +/- .7 D. Vitreous chamber depths showed a main effect for drug conditions with less depth change in response to defocus shown for Ba(2+ relative to Saline, while bumetanide injected eyes showed a trend to increased depth without a significant interaction with applied defocus. The results indicate that both K channels and the NKCC cotransporter play a role in refractive compensation with NKCC blockade showing far more specificity for negative, compared with positive, lens defocus. Probable sites of action relevant to refractive control include the apical retinal pigment epithelium membrane and the photoreceptor/ON bipolar synapse. The similarities between the biometric effects of NKCC inhibition and biometric reports of the blockade of the retinal ON response, suggest a

  9. KCl-Dependent Release of Mitochondrial Membrane-Bound Arginase Appears to Be a Novel Variant of Arginase-II

    Suman, Mishra; Rajnikant, Mishra

    2016-01-01

    Arginase regulates arginine metabolism, ornithine-urea cycle, and immunological surveillance. Arginase-I is predominant in cytosol, and arginase-II is localised in the mitochondria. A mitochondrial membrane-bound arginase has also been proposed to be adsorbed with outer membrane of mitochondria which gets released by 150 mM potassium chloride (KCl). It is presumed that inclusion of 150 mM KCl in the homogenization medium would not only facilitate release of arginase bound with outer membrane of mitochondria but also affect functional anatomy of mitochondria, mitochondrial enzymes, and proteins. Therefore, it has been intended to characterize KCl-dependent release of mitochondrial membrane-bound arginase from liver of mice. Results provide advancement in the area of arginase biology and suggest that fraction of mitochondrial membrane-bound arginase contains mitochondrial arginase-II and a variant of arginase-II. PMID:27293971

  10. Computer simulation of electron states of the isoelectronic substitutional impurities in quantum wire of KCl with edge dislocation

    The electron states of quantum wires KCl, KCl : Br, and KCl : I with an edge dislocations were investigated. The main problem was in study of dislocation influence on localized electron states connected with substitutional isoelectronic impurities Br− and I− in the neighborhood of edge dislocation line. The tight-binding semi-empirical band approximation, semi-empirical and non-empirical cluster approach were used. Semi-empirical calculations were carried out in framework of model [1,2]. Besides, the algorithms for electronic levels calculations of polar nanosystems with the partial self-consistency [3] were used. The computer simulation results lead to the conclusion that the substitutional isoelectronic impurity anions Br− and I− located near the dislocation line capture the holes more efficiently than in bulk of systems without dislocations

  11. X-ray and optical study on point defect formation and interaction under irradiation adn doping of KCl

    Optical and X-ray diffuse scattering methods have been applied to investigate structural changes, taking place in KCl crystals during irradiation with γ-quanta and doping with barium. It is shown that γ-irradiation of ''pure'' and doped KCl crystals mainly leads to formation of F-centers and spherical vacancy complexes. F-center concentration in irradiated addition crystals (3x10-6) has turned out to be 25% lower, than in irradiated pure ones (4x10-6), which is connected with interaction of radiation and addition defects. The type of defects, causing assymetry in the distribution of diffuse scattering has been determined. Appearance of scattering ability modulation over direction during irradiation of KCl pure crystals has been found. Critical radius of spherical complexes formed during irradiation has been estimated, it appeared to be 2.5 a, where a is a lattice period

  12. Molecular cloning of a cDNA for a putative choline co-transporter from Limulus CNS.

    Wang, Y; Cao, Z; Newkirk, R F; Ivy, M T; Townsel, J G

    2001-05-01

    It is well documented that the sodium dependent, hemicholinium-3 sensitive, high affinity choline co-transporter is rate limiting in the biosynthesis of acetylcholine and is essential to cholinergic transmission. Until recently this transporter had eluded cloning. Okuda et al. (2000. Nature Neurosci. 3, 120-125) recently reported the successful cloning of the choline co-transporter in Caenorhabditis elegans (CHO-1) and rat (CHT1). We report herein the cloning of the choline co-transporter in the horseshoe crab, Limulus polyphemus. Through the use of a series of degenerate primers selected from consensus sequences of CHO-1 and CHT1, we generated two probes that were used to search a Limulus cDNA library produced from central nervous system (CNS) tissue. The full length nucleotide sequence of the Limulus homolog consists of 3368 bp which includes an open reading frame (ORF) that predicts a protein of 579 amino acids and two non-translation regions (NTR), one at the 3' end and the other at the 5' end. The amino acid sequence has 46% identity with rat CHT1 and 50% identity with both CHO-1 in C. elegans and the recently cloned human co-transporter (hCHT; Apparsundaram et al., 2000. Biochem. Biophys. Res. Commun. 276, 862-867; Okuda and Haga, 2000. FEBS Lett. 484, 92-97). Hydropathy plot analysis predicts the Limulus choline co-transporter (LChCoT) to have thirteen transmembrane domains (TMD), with the N-terminus oriented extracellularly and the C-terminus oriented intracellularly. Northern blot analyses using cDNA probes designed from LChCoT cDNA sequences revealed its distribution specifically in central nervous system structures. On the other hand it was not found in non-nervous tissues. The successful cloning of LChCoT, which was shown to be a member of the sodium-dependent glucose transporter family (SLGT), should prove useful in the determination of its physiological regulation, including its intracellular trafficking. PMID:11368908

  13. Clinical Pharmacokinetic, Pharmacodynamic, and Drug-Drug Interaction Profile of Canagliflozin, a Sodium-Glucose Co-transporter 2 Inhibitor.

    Devineni, Damayanthi; Polidori, David

    2015-10-01

    The sodium-glucose co-transporter 2 (SGLT2) inhibitors represent novel therapeutic approaches in the management of type 2 diabetes mellitus; they act on kidneys to decrease the renal threshold for glucose (RTG) and increase urinary glucose excretion (UGE). Canagliflozin is an orally active, reversible, selective SGLT2 inhibitor. Orally administered canagliflozin is rapidly absorbed achieving peak plasma concentrations in 1-2 h. Dose-proportional systemic exposure to canagliflozin has been observed over a wide dose range (50-1600 mg) with an oral bioavailability of 65 %. Canagliflozin is glucuronidated into two inactive metabolites, M7 and M5 by uridine diphosphate-glucuronosyltransferase (UGT) 1A9 and UGT2B4, respectively. Canagliflozin reaches steady state in 4 days, and there is minimal accumulation observed after multiple dosing. Approximately 60 % and 33 % of the administered dose is excreted in the feces and urine, respectively. The half-life of orally administered canagliflozin 100 or 300 mg in healthy participants is 10.6 and 13.1 h, respectively. No clinically relevant differences are observed in canagliflozin exposure with respect to age, race, sex, and body weight. The pharmacokinetics of canagliflozin remains unaffected by mild or moderate hepatic impairment. Systemic exposure to canagliflozin is increased in patients with renal impairment relative to those with normal renal function; however, the efficacy is reduced in patients with renal impairment owing to the reduced filtered glucose load. Canagliflozin did not show clinically relevant drug interactions with metformin, glyburide, simvastatin, warfarin, hydrochlorothiazide, oral contraceptives, probenecid, and cyclosporine, while co-administration with rifampin modestly reduced canagliflozin plasma concentrations and thus may necessitate an appropriate monitoring of glycemic control. Canagliflozin increases UGE and suppresses RTG in a dose-dependent manner, thereby lowering the plasma glucose

  14. The Human Sodium-Glucose Cotransporter (hSGLT1) Is a Disulfide-Bridged Homodimer with a Re-Entrant C-Terminal Loop

    Sasseville, Louis J.; Morin, Michael; Coady, Michael J.; Blunck, Rikard; Lapointe, Jean-Yves

    2016-01-01

    Na-coupled cotransporters are proteins that use the trans-membrane electrochemical gradient of Na to activate the transport of a second solute. The sodium-glucose cotransporter 1 (SGLT1) constitutes a well-studied prototype of this transport mechanism but essential molecular characteristics, namely its quaternary structure and the exact arrangement of the C-terminal transmembrane segments, are still debated. After expression in Xenopus oocytes, human SGLT1 molecules (hSGLT1) were labelled on an externally accessible cysteine residue with a thiol-reactive fluorophore (tetramethylrhodamine-C5-maleimide, TMR). Addition of dipicrylamine (DPA, a negatively-charged amphiphatic fluorescence “quencher”) to the fluorescently-labelled oocytes is used to quench the fluorescence originating from hSGLT1 in a voltage-dependent manner. Using this arrangement with a cysteine residue introduced at position 624 in the loop between transmembrane segments 12 and 13, the voltage-dependent fluorescence signal clearly indicated that this portion of the 12–13 loop is located on the external side of the membrane. As the 12–13 loop begins on the intracellular side of the membrane, this suggests that the 12–13 loop is re-entrant. Using fluorescence resonance energy transfer (FRET), we observed that different hSGLT1 molecules are within molecular distances from each other suggesting a multimeric complex arrangement. In agreement with this conclusion, a western blot analysis showed that hSGLT1 migrates as either a monomer or a dimer in reducing and non-reducing conditions, respectively. A systematic mutational study of endogenous cysteine residues in hSGLT1 showed that a disulfide bridge is formed between the C355 residues of two neighbouring hSGLT1 molecules. It is concluded that, 1) hSGLT1 is expressed as a disulfide bridged homodimer via C355 and that 2) a portion of the intracellular 12–13 loop is re-entrant and readily accessible from the extracellular milieu. PMID:27137918

  15. The Human Sodium-Glucose Cotransporter (hSGLT1 Is a Disulfide-Bridged Homodimer with a Re-Entrant C-Terminal Loop.

    Louis J Sasseville

    Full Text Available Na-coupled cotransporters are proteins that use the trans-membrane electrochemical gradient of Na to activate the transport of a second solute. The sodium-glucose cotransporter 1 (SGLT1 constitutes a well-studied prototype of this transport mechanism but essential molecular characteristics, namely its quaternary structure and the exact arrangement of the C-terminal transmembrane segments, are still debated. After expression in Xenopus oocytes, human SGLT1 molecules (hSGLT1 were labelled on an externally accessible cysteine residue with a thiol-reactive fluorophore (tetramethylrhodamine-C5-maleimide, TMR. Addition of dipicrylamine (DPA, a negatively-charged amphiphatic fluorescence "quencher" to the fluorescently-labelled oocytes is used to quench the fluorescence originating from hSGLT1 in a voltage-dependent manner. Using this arrangement with a cysteine residue introduced at position 624 in the loop between transmembrane segments 12 and 13, the voltage-dependent fluorescence signal clearly indicated that this portion of the 12-13 loop is located on the external side of the membrane. As the 12-13 loop begins on the intracellular side of the membrane, this suggests that the 12-13 loop is re-entrant. Using fluorescence resonance energy transfer (FRET, we observed that different hSGLT1 molecules are within molecular distances from each other suggesting a multimeric complex arrangement. In agreement with this conclusion, a western blot analysis showed that hSGLT1 migrates as either a monomer or a dimer in reducing and non-reducing conditions, respectively. A systematic mutational study of endogenous cysteine residues in hSGLT1 showed that a disulfide bridge is formed between the C355 residues of two neighbouring hSGLT1 molecules. It is concluded that, 1 hSGLT1 is expressed as a disulfide bridged homodimer via C355 and that 2 a portion of the intracellular 12-13 loop is re-entrant and readily accessible from the extracellular milieu.

  16. The Human Sodium-Glucose Cotransporter (hSGLT1) Is a Disulfide-Bridged Homodimer with a Re-Entrant C-Terminal Loop.

    Sasseville, Louis J; Morin, Michael; Coady, Michael J; Blunck, Rikard; Lapointe, Jean-Yves

    2016-01-01

    Na-coupled cotransporters are proteins that use the trans-membrane electrochemical gradient of Na to activate the transport of a second solute. The sodium-glucose cotransporter 1 (SGLT1) constitutes a well-studied prototype of this transport mechanism but essential molecular characteristics, namely its quaternary structure and the exact arrangement of the C-terminal transmembrane segments, are still debated. After expression in Xenopus oocytes, human SGLT1 molecules (hSGLT1) were labelled on an externally accessible cysteine residue with a thiol-reactive fluorophore (tetramethylrhodamine-C5-maleimide, TMR). Addition of dipicrylamine (DPA, a negatively-charged amphiphatic fluorescence "quencher") to the fluorescently-labelled oocytes is used to quench the fluorescence originating from hSGLT1 in a voltage-dependent manner. Using this arrangement with a cysteine residue introduced at position 624 in the loop between transmembrane segments 12 and 13, the voltage-dependent fluorescence signal clearly indicated that this portion of the 12-13 loop is located on the external side of the membrane. As the 12-13 loop begins on the intracellular side of the membrane, this suggests that the 12-13 loop is re-entrant. Using fluorescence resonance energy transfer (FRET), we observed that different hSGLT1 molecules are within molecular distances from each other suggesting a multimeric complex arrangement. In agreement with this conclusion, a western blot analysis showed that hSGLT1 migrates as either a monomer or a dimer in reducing and non-reducing conditions, respectively. A systematic mutational study of endogenous cysteine residues in hSGLT1 showed that a disulfide bridge is formed between the C355 residues of two neighbouring hSGLT1 molecules. It is concluded that, 1) hSGLT1 is expressed as a disulfide bridged homodimer via C355 and that 2) a portion of the intracellular 12-13 loop is re-entrant and readily accessible from the extracellular milieu. PMID:27137918

  17. The Sodium Glucose Cotransporter SGLT1 Is an Extremely Efficient Facilitator of Passive Water Transport.

    Erokhova, Liudmila; Horner, Andreas; Ollinger, Nicole; Siligan, Christine; Pohl, Peter

    2016-04-29

    The small intestine is void of aquaporins adept at facilitating vectorial water transport, and yet it reabsorbs ∼8 liters of fluid daily. Implications of the sodium glucose cotransporter SGLT1 in either pumping water or passively channeling water contrast with its reported water transporting capacity, which lags behind that of aquaporin-1 by 3 orders of magnitude. Here we overexpressed SGLT1 in MDCK cell monolayers and reconstituted the purified transporter into proteoliposomes. We observed the rate of osmotic proteoliposome deflation by light scattering. Fluorescence correlation spectroscopy served to assess (i) SGLT1 abundance in both vesicles and plasma membranes and (ii) flow-mediated dilution of an aqueous dye adjacent to the cell monolayer. Calculation of the unitary water channel permeability, pf, yielded similar values for cell and proteoliposome experiments. Neither the absence of glucose or Na(+), nor the lack of membrane voltage in vesicles, nor the directionality of water flow grossly altered pf Such weak dependence on protein conformation indicates that a water-impermeable occluded state (glucose and Na(+) in their binding pockets) lasts for only a minor fraction of the transport cycle or, alternatively, that occlusion of the substrate does not render the transporter water-impermeable as was suggested by computational studies of the bacterial homologue vSGLT. Although the similarity between the pf values of SGLT1 and aquaporin-1 makes a transcellular pathway plausible, it renders water pumping physiologically negligible because the passive flux would be orders of magnitude larger. PMID:26945065

  18. Abnormal expression of cerebrospinal fluid cation chloride cotransporters in patients with Rett syndrome.

    Sofia Temudo Duarte

    Full Text Available OBJECTIVE: Rett Syndrome is a progressive neurodevelopmental disorder caused mainly by mutations in the gene encoding methyl-CpG-binding protein 2. The relevance of MeCP2 for GABAergic function was previously documented in animal models. In these models, animals show deficits in brain-derived neurotrophic factor, which is thought to contribute to the pathogenesis of this disease. Neuronal Cation Chloride Cotransporters (CCCs play a key role in GABAergic neuronal maturation, and brain-derived neurotrophic factor is implicated in the regulation of CCCs expression during development. Our aim was to analyse the expression of two relevant CCCs, NKCC1 and KCC2, in the cerebrospinal fluid of Rett syndrome patients and compare it with a normal control group. METHODS: The presence of bumetanide sensitive NKCC1 and KCC2 was analysed in cerebrospinal fluid samples from a control pediatric population (1 day to 14 years of life and from Rett syndrome patients (2 to 19 years of life, by immunoblot analysis. RESULTS: Both proteins were detected in the cerebrospinal fluid and their levels are higher in the early postnatal period. However, Rett syndrome patients showed significantly reduced levels of KCC2 and KCC2/NKCC1 ratio when compared to the control group. CONCLUSIONS: Reduced KCC2/NKCC1 ratio in the cerebrospinal fluid of Rett Syndrome patients suggests a disturbed process of GABAergic neuronal maturation and open up a new therapeutic perspective.

  19. LLC-PK1 cells express Na+-lactate cotransport in apical membranes after confluency

    L-[3H]lactate uptake was characterized in LLC-PK1 cell apical membrane vesicles obtained by intensive culture on microcarrier beads. The apical membrane preparation technique involved MgCl2 precipitation. Na+-dependent L-[3H]lactate uptake was present only after confluency; its appearance paralleled the subcellular localization of aminopeptidase in apical membranes. L-[3H]lactate uptake was Na+-dependent and electrogenic. Only the Na+-dependent component of L[3H]lactate uptake was saturable with one family of independent carriers. The apparent affinity constant was 1.1 ± 0.25 mM and the apparent maximal velocity was 29 ± 3 nmol·mg-1·min-1. The Na+-lactate cotransport stoichiometry was 2 Na+ for 1 lactate. The specificity of the L-lactate transport system was compatible with that of the monocarboxylic acid pathway described previously brush-border membranes of kidney cortex and discrete from the tricarboxylic acid carrier, the D-glucose transporter, and the general pathway for anions. The LLC-PK1 cell line appears to be a useful tool for study of the regulation of L-lactate uptake and biosynthesis of the renal monocarboxylic acid transporter

  20. Sodium-glucose cotransporter 2 inhibitors with insulin in type 2 diabetes: Clinical perspectives

    Mathew John

    2016-01-01

    Full Text Available The treatment of type 2 diabetes is a challenging problem. Most subjects with type 2 diabetes have progression of beta cell failure necessitating the addition of multiple antidiabetic agents and eventually use of insulin. Intensification of insulin leads to weight gain and increased risk of hypoglycemia. Sodium-glucose cotransporter 2 (SGLT2 inhibitors are a class of antihyperglycemic agents which act by blocking the SGLT2 in the proximal tubule of the kidney. They have potential benefits in terms of weight loss and reduction of blood pressure in addition to improvements in glycemic control. Further, one of the SGLT2 inhibitors, empagliflozin has proven benefits in reducing adverse cardiovascular (CV outcomes in a CV outcome trial. Adding SGLT2 inhibitors to insulin in subjects with type 2 diabetes produced favorable effects on glycemic control without the weight gain and hypoglycemic risks associated with insulin therapy. The general risks of increased genital mycotic infections, urinary tract infections, volume, and osmosis-related adverse effects in these subjects were similar to the pooled data of individual SGLT2 inhibitors. There are subsets of subjects with type 2 diabetes who may have insulin deficiency, beta cell autoimmunity, or is prone to diabetic ketoacidosis. In these subjects, SGLT2 inhibitors should be used with caution to prevent the rare risks of ketoacidosis.

  1. Blocking effect of colloids on arsenate adsorption during co-transport through saturated sand columns.

    Ma, Jie; Guo, Huaming; Lei, Mei; Wan, Xiaoming; Zhang, Hanzhi; Feng, Xiaojuan; Wei, Rongfei; Tian, Liyan; Han, Xiaokun

    2016-06-01

    Transport of environmental pollutants through porous media is influenced by colloids. Co-transport of As(V) and soil colloids at different pH were systematically investigated by monitoring breakthrough curves (BTCs) in saturated sand columns. A solute transport model was applied to characterize transport and retention sites of As(V) in saturated sand in the presence of soil colloids. A colloid transport model and the DLVO theory were used to reveal the mechanism and hypothesis of soil colloid-promoted As(V) transport in the columns. Results showed that rapid transport of soil colloids, regulated by pH and ionic strength, promoted As(V) transport by blocking As(V) adsorption onto sand, although soil colloids had low adsorption for As(V). The promoted transport was more significant at higher concentrations of soil colloids (between 25 mg L(-1) and 150 mg L(-1)) due to greater blocking effect on As(V) adsorption onto the sand surfaces. The blocking effect of colloids was explained by the decreases in both instantaneous (equilibrium) As adsorption and first-order kinetic As adsorption on the sand surface sites. The discovery of this blocking effect improves our understanding of colloid-promoted As transport in saturated porous media, which provides new insights into role of colloids, especially colloids with low As adsorption capacity, in As transport and mobilization in soil-groundwater systems. PMID:27017140

  2. Sodium-glucose co-transporter-2 inhibitors as anti-diabetic agents: a review

    Chirag B. Mistry

    2015-10-01

    Full Text Available The incidence and prevalence of Type 2 diabetes mellitus (T2DM have been increasing worldwide. However, existing therapeutic classes of anti-diabetic drugs are not adequately effective in achieving and maintaining long-term glycemic control in the most patients. The majority of the drugs control blood sugar without addressing the basic pathology of insulin resistance and relative deficiency. Moreover, side effects such as hypoglycemia and weight gain, of both new and established drugs need to be considered prior to treating a patient. An emerging anti-hyperglycemic intervention, the sodium glucose co-transporter 2 (SGLT2 inhibitor acts by a novel mechanism. Under physiological conditions, SGLT2 accounts for 90% of the glucose re-absorption in the kidney, while the SGLT2 inhibitors result in an increase in urinary excretion of glucose and lower plasma glucose levels. Here, the pros and cons of SGLT2 inhibitors are considered, while approaching a patient with T2DM. The basic biochemistry and physiology underlying the mechanisms of SGLT2 inhibitors are discussed alongside its clinical pharmacology, with a focus on metabolic changes associated with urinary glucose loss. Finally, a consideration of Food and Drug Administration safety concerns associated with acidosis due to SGLT2 inhibitor usage is presented, to allow a complete understanding of the utility of these molecules in the light of existing T2DM therapies. [Int J Basic Clin Pharmacol 2015; 4(5.000: 815-821

  3. Characterization and comparison of sodium-glucose cotransporter 2 inhibitors in pharmacokinetics, pharmacodynamics, and pharmacologic effects.

    Tahara, Atsuo; Takasu, Toshiyuki; Yokono, Masanori; Imamura, Masakazu; Kurosaki, Eiji

    2016-03-01

    The sodium-glucose cotransporter (SGLT) 2 offer a novel approach to treating type 2 diabetes by reducing hyperglycaemia via increased urinary glucose excretion. In the present study, the pharmacokinetic, pharmacodynamic, and pharmacologic properties of all six SGLT2 inhibitors commercially available in Japan were investigated and compared. Based on findings in normal and diabetic mice, the six drugs were classified into two categories, long-acting: ipragliflozin and dapagliflozin, and intermediate-acting: tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin. Long-acting SGLT2 inhibitors exerted an antihyperglycemic effect with lower variability of blood glucose level via a long-lasting increase in urinary glucose excretion. In addition, ipragliflozin and luseogliflozin exhibited superiority over the others with respect to fast onset of pharmacological effect. Duration and onset of the pharmacologic effects seemed to be closely correlated with the pharmacokinetic properties of each SGLT2 inhibitor, particularly with respect to high distribution and long retention in the target organ, the kidney. While all six SGLT2 inhibitors were significantly effective in increasing urinary glucose excretion and reducing hyperglycemia, our findings suggest that variation in the quality of daily blood glucose control associated with duration and onset of pharmacologic effects of each SGLT2 inhibitor might cause slight differences in rates of improvement in type 2 diabetes. PMID:26970780

  4. Sodium-Glucose Cotransporter 2 Inhibitors: Possible Anti-Atherosclerotic Effects Beyond Glucose Lowering.

    Yanai, Hidekatsu; Katsuyama, Hisayuki; Hamasaki, Hidetaka; Adachi, Hiroki; Moriyama, Sumie; Yoshikawa, Reo; Sako, Akahito

    2016-01-01

    The new drug for type 2 diabetes, the sodium-glucose cotransporter 2 (SGLT-2) inhibitor, is reversible inhibitor of SGLT-2, leading to reduction of renal glucose reabsorption and decrease of plasma glucose, in an insulin-independent manner. In addition to glucose control, the management of coronary risk factors is very important for patients with diabetes. Here we reviewed published articles about the possible anti-atherosclerotic effects beyond glucose lowering of the SGLT-2 inhibitors. We searched by using Pubmed, and found 770 published articles about SGLT-2 inhibitors. Among 10 kinds of SGLT-2 inhibitors, the number of published articles about dapagliflozin was the greatest among SGLT-2 inhibitors. Since SGLT-2 inhibitors have similar chemical structures, we concentrated on the published articles about dapagliflozin. SGLT-2 inhibitors are proved to be significantly associated with weight loss and reduction of blood pressure by a relatively large number of studies. The studies investigating effects of dapagliflozin on visceral fat, insulin sensitivity, serum lipids, inflammation and adipocytokines are very limited. An influence of increase in glucagon secretion by SGLT-2 inhibitors on metabolic risk factors remains unknown. PMID:26668677

  5. Sodium-glucose cotransporter 2 inhibitors with insulin in type 2 diabetes: Clinical perspectives

    John, Mathew; Gopinath, Deepa; Jagesh, Rejitha

    2016-01-01

    The treatment of type 2 diabetes is a challenging problem. Most subjects with type 2 diabetes have progression of beta cell failure necessitating the addition of multiple antidiabetic agents and eventually use of insulin. Intensification of insulin leads to weight gain and increased risk of hypoglycemia. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of antihyperglycemic agents which act by blocking the SGLT2 in the proximal tubule of the kidney. They have potential benefits in terms of weight loss and reduction of blood pressure in addition to improvements in glycemic control. Further, one of the SGLT2 inhibitors, empagliflozin has proven benefits in reducing adverse cardiovascular (CV) outcomes in a CV outcome trial. Adding SGLT2 inhibitors to insulin in subjects with type 2 diabetes produced favorable effects on glycemic control without the weight gain and hypoglycemic risks associated with insulin therapy. The general risks of increased genital mycotic infections, urinary tract infections, volume, and osmosis-related adverse effects in these subjects were similar to the pooled data of individual SGLT2 inhibitors. There are subsets of subjects with type 2 diabetes who may have insulin deficiency, beta cell autoimmunity, or is prone to diabetic ketoacidosis. In these subjects, SGLT2 inhibitors should be used with caution to prevent the rare risks of ketoacidosis. PMID:26904465

  6. Sodium glucose co-transporter inhibitors - A new class of old drugs.

    Malhotra, Aneeta; Kudyar, Surbhi; Gupta, Anil K; Kudyar, Rattan P; Malhotra, Pavan

    2015-01-01

    Sodium glucose co-transporter (SGLT) inhibitors are a new class of drugs which are used in the pharmacotherapy of Type-II diabetes, which happens to be a major risk factor for developing both micro as well as macro-vascular complications. These drugs inhibit the glucose reabsorption by inhibiting SGLT, which exhibits a novel and promising mechanism of action by promoting the urinary glucose excretion hence providing a basis of therapeutic intervention. Results of SGLT-II inhibitors are very encouraging as there is a significant elevation of GLP-1 level, which forms the basis of relevance in treatment of diabetes. It targets the HbA1C and keeps a check on its levels. It also exerts other positive benefits such as weight loss, reduction in blood glucose levels, reduction in blood pressure and improvement in insulin resistance and β-cell dysfunction: All contributing to effective glycemic control. SGLT inhibition will develop as effective modality as it has the capability of inhibiting reabsorption of greater percentage of filtered glucose load. PMID:26539362

  7. Sodium-glucose cotransporter-2 inhibitors and genital and urinary tract infections in type 2 diabetes.

    Arakaki, Richard F

    2016-05-01

    Coincident with the high and increasing worldwide prevalence of type 2 diabetes (T2D), a growing armamentarium of antidiabetes medications has been introduced to target different organ systems that play a role in the pathophysiology of T2D. Among these, the sodium-glucose cotransporter-2 (SGLT-2) inhibitors were introduced in the United States in 2013 as a new treatment option to address the hyperglycemia associated with T2D. SGLT-2 inhibitors decrease renal glucose reabsorption, resulting in glucosuria, alleviation of hyperglycemia, and modest weight loss and are associated with a low risk of hypoglycemia. The SGLT-2 inhibitors have been linked to an increased incidence of genital mycotic infections and, to a lesser extent, urinary tract infections, which may limit their utility in some patients. This review examines the prevalence, recurrence rates, treatment options, and responses to treatment of genital and urinary tract infections in patients with T2D receiving SGLT-2 inhibitors, with the aim of guiding clinicians in the most effective use of these agents for the treatment of hyperglycemia. PMID:26982554

  8. Sodium-Glucose Cotransporter Inhibitors: Effects on Renal and Intestinal Glucose Transport: From Bench to Bedside.

    Mudaliar, Sunder; Polidori, David; Zambrowicz, Brian; Henry, Robert R

    2015-12-01

    Type 2 diabetes is a chronic disease with disabling micro- and macrovascular complications that lead to excessive morbidity and premature mortality. It affects hundreds of millions of people and imposes an undue economic burden on populations across the world. Although insulin resistance and insulin secretory defects play a major role in the pathogenesis of hyperglycemia, several other metabolic defects contribute to the initiation/worsening of the diabetic state. Prominent among these is increased renal glucose reabsorption, which is maladaptive in patients with diabetes. Instead of an increase in renal glucose excretion, which could ameliorate hyperglycemia, there is an increase in renal glucose reabsorption, which helps sustain hyperglycemia in patients with diabetes. The sodium-glucose cotransporter (SGLT) 2 inhibitors are novel antidiabetes agents that inhibit renal glucose reabsorption and promote glucosuria, thereby leading to reductions in plasma glucose concentrations. In this article, we review the long journey from the discovery of the glucosuric agent phlorizin in the bark of the apple tree through the animal and human studies that led to the development of the current generation of SGLT2 inhibitors. PMID:26604280

  9. Electrochemical studies and analysis of 1–10 wt% UCl3 concentrations in molten LiCl–KCl eutectic

    Three electrochemical methods – cyclic voltammetry (CV), chronopotentiometry (CP), and anodic stripping voltammetry (ASV) – were applied to solutions of up to 10 wt% UCl3 in the molten LiCl–KCl eutectic salt at 500 °C to determine electrochemical properties and behaviors and to help provide a scientific basis for the development of an in situ electrochemical probe for determining the concentration of uranium in a used nuclear fuel electrorefiner. Diffusion coefficients of UCl4 and UCl3 were calculated to be (6.72 ± 0.360) × 10−6 cm2/s and (1.04 ± 0.17) × 10−5 cm2/s, respectively. Apparent standard reduction potentials were determined to be (−0.381 ± 0.013) V and (−1.502 ± 0.076) V vs. 5 mol% Ag/AgCl or (−1.448 ± 0.013) V and (−2.568 ± 0.076) V vs. Cl2/Cl− for the U(IV)/U(III) and U(III)/U redox couples, respectively. In comparing this data with supercooled thermodynamic data to determine activity coefficients, the thermodynamic database used was important with resulting activity coefficients ranging from 2.34 × 10−3 to 1.08 × 10−2 for UCl4 and 4.94 × 10−5 to 4.50 × 10−4 for UCl3. Of anodic stripping voltammetry and cyclic voltammetry anodic or cathodic peaks, the CV cathodic peak height divided by square root of scan rate was shown to be the most reliable method of determining UCl3 concentration in the molten salt

  10. Labelling by 3H-N-ethylmaleimide of diamide-oxidized thiol groups in sheep red blood cell (SRBC) membranes

    Exposure of SRBC to the thiol oxidant diamide activates K:Cl cotransport, reversed upon metabolic restoration of cellular glutathione suggesting redox control of the K:Cl cotransporter, as well as by subsequent exposure to dithiothreitol (DTT). The thiols crucial for activation may be either on the transporter or on a membrane or cytoplasmic regulator. To test this hypothesis, the authors attempted to label with 3H-N-ethylmaleimide (3H-NEM) the thiols protected by diamide oxidation and reduced subsequently by DTT. SRBC were first treated with a diamide concentration activating K:Cl cotransport, followed by a second exposure to unlabeled (cold) NEM to block any non-oxidized thiol, and then hemolyzed to obtain white ghosts. The ghosts were again treated with cold NEM and after reduction by DTT exposed to 3H-NEM with and without cold NEM. Saturation labelling by 3H-NEM of diamide protected groups occurred in the range of CTT concentrations inactivating the diamide-stimulated K:Cl cotransport. Saturation labelling with 3H-NEM occurred at about 25μM NEM suggesting a Ki of less than 10μM NEM. The number of diamide protected thiols was about 5-10,000/cell membrane. At 100μM 3H-NEM, SRBC not treated with diamide possess at least 100,000 thiols cell and this number is likely to rise by tenfold at higher NEM concentrations. Thus, diamide protected about 1/1,000 of the membrane thiols in both genetically low and high K SRBC, assayed under conditions where K:Cl cotransport is activated in intact cells. Therefore, at least some of the thiols crucial for potential regulation of K:Cl cotransport reside within the plasma membrane

  11. Study of the Eu2+ and Eu3+ coexist in LiCl-KCl Eutectic Melt by Spectrophotometry and Electrochemistry Method

    In order to ensure the pyrochemical process, it is necessary to understand the chemical behavior of lanthanides in the molten salt. Through most of lanthanides in molten salts take trivalent states, Eu, Sm, and Yb are possible to take divalent states under reducing conditions, and Eu(II) is the most stable among them. Those reports suggest the existence of Eu in the chloride systems. In electrochemical analysis with molten salts, yttria stabilized zirconia membrane electrodes (YSZME) are largely used as an activity indicator of oxide anion, O2-. In the present study, the effect of the coexisted Eu2+ on the potentiometric titration of Eu3+ was examined. The spectrophotometry and electrochemistry method could b used to measure the ratio of [Eu2+]/[Eu3+]efficiently. The existence of the europium divalent in the LiCl-KCl-EuCl3 solution has been demonstrated by potentiometric titration method with YSZ electrode and Pt wire as a working electrode

  12. Electrochemical separation of uranium and cerium in molten LiCl-KCl

    The electrochemical separation of uranium from cerium in LiCl–KCl eutectic and the electrochemical behavior of Ce(III) were studied. According to the cyclic voltammogram of Ce(III) and the former result of U(III), electrodeposition potential was determined at -1.65 V (vs Ag/AgCl). The uranium metal was successfully deposited and separated from cerium. The morphology of deposit and cross section of electrode were investigated by SEM, firstly uranium deposit alloys with stainless steel and forms a thin transition layer, and secondly the uranium metal layer grows from the transition layer. The separation factors of uranium/cerium on different recovery ratios were determined through a series of steps. It was found that the content of cerium in the deposit and separation factors declined with increasing the initial concentration of U3+ in molten salts; the separation factors remained stable at around 20 in different uranium recovery ratios. (author)

  13. Effect of Eu2+ concentration on the lattice parameter and density of KCl crystals

    Precise lattice parameter (a) measurements reveal that with increasing Eu2+ concentration the KCl matrix undergoes a continuous contraction in the whole range examined up to 350 ppm, reaching the value Δa/a = -4.8 x 10-4. The above effect suggests a strong interaction between one impurity dipole and a fragment of the lattice comprizing several unit cells. The density increments obtained from the flotation data are considerably lower from those estimated from the X-ray data. The above difference is explained in terms of high contents of excess (over-equilibrium) vacancy pairs (e.g. 1.3 x 1019 cm-3 in a sample containing 175 ppm Eu2+) existing in the form of aggregates or voids. (author)

  14. Thermoluminescent monitoring of the solar ultraviolet radiation with KCl: Eu2+ crystals

    In this work it has been investigating the Tl properties of KCl: Eu2+ subjected to solar direct radiation. Also it was realized irradiation with the Deuterium and Xenon lamps. It was used a set of filters and a Katos monochromator 0.25 M to determine the spectral response to Tl peaks and a study of them with respect to the duration of the Sun irradiation. After of the Sun irradiation the Tl curves show several peaks between the ambient temperature and 673 K. The relation between peaks depends strongly of the irradiation time and the different solar light wavelength. It is possible to divide the Tl peaks in two groups. The first one (T473 K) is not too sensitive but is more stable under optical whitening. Here the obtained results are discussed with respect to UV dosemeters development for environment which facilitate to obtain direct measurements of the UV index. (Author)

  15. Measurements of pressure for the TiH/sub x//KClO4 system

    An investigation was conducted to measure the pressure obtained when the pyrotechnic mixture TiH/sub x//KClO4 was ignited in a confined variable-volume system. It was possible to derive an expression of the form PV/sup γ/ = k for the pressure-volume relationship obtained. This expression is a polytropic expansion of the ideal gas equation that best fits the data generated. For this particular work, values of γ = 0.53 and k = 69.3 were obtained where P is in megapascals and V is in cubic centimeters. In addition, estimates of the reaction rates were calculated based on the times to achieve maximum pressure for a given volume system. An explicit expression relating rate to pressure was derived by a simplified least-squares fit of the data obtained

  16. Electrolysis of plutonium nitride in LiCl-KCl eutectic melts

    Shirai, O.; Iwai, T.; Shiozawa, K.; Suzuki, Y.; Sakamura, Y.; Inoue, T.

    2000-01-01

    The electrolysis of plutonium nitride, PuN, was investigated in the LiCl-KCl eutectic salt with 0.54 wt% PuCl 3 at 773 K in order to understand the dissolution of PuN at the anode and the deposition of metal at the cathode from the viewpoint of the application of a pyrochemical process to nitride fuel cycle. It was found from cyclic voltammetry that the electrochemical dissolution of PuN began nearly at the theoretically evaluated potential and this reaction was irreversible. Several grams of plutonium metal were successfully recovered at the molybdenum electrode as a deposit with a current efficiency of about 90%, although some fractions of the deposited plutonium often fell from the molybdenum electrode.

  17. Electrolysis of plutonium nitride in LiCl-KCl eutectic melts

    The electrolysis of plutonium nitride, PuN, was investigated in the LiCl-KCl eutectic salt with 0.54 wt% PuCl3 at 773 K in order to understand the dissolution of PuN at the anode and the deposition of metal at the cathode from the viewpoint of the application of a pyrochemical process to nitride fuel cycle. It was found from cyclic voltammetry that the electrochemical dissolution of PuN began nearly at the theoretically evaluated potential and this reaction was irreversible. Several grams of plutonium metal were successfully recovered at the molybdenum electrode as a deposit with a current efficiency of about 90%, although some fractions of the deposited plutonium often fell from the molybdenum electrode

  18. Evaluation of apparent standard potentials of curium in LiCl-KCl eutectic melt

    Electrochemical properties of curium (Cm-244) dissolved in LiCl-KCl eutectic melt were studied in the temperature range of 718 - 823 K. A small electrochemical cell used in the present study was designed to measure electrochemical properties of highly radioactive Cm-244, the maximum handling amount of which is 30 mg in our hot cells, dissolved in molten salts. Apparent standard potentials of Cm3+/Cm couple obtained in the present study, E°* (Cm3+/Cm) = (-3.236 ± 0.011) + (4.86 ± 0.14) × 10-4 T, reasonably agree with Osipenko's data (2011) and are lower than Martinot's data (1975). The validity of the data obtained in the present study was discussed by comparing with the reported data of other transuranic elements. (author)

  19. Electrochemical preparation and spectroelectrochemical study of neptunium chloride complexes in LiCl-KCl eutectic melts

    We prepared neptunium chloride complexes electrochemically and performed spectroelectrochemical measurements of neptunium ions in LiCl-KCl eutectic melts at 450 deg C, where the neptunium concentrations studied were in the range of 0.1-1 mM. We observed a highly absorbing f-d transition band of Np3+ at 383 nm, which was used to determine an formal potential of the Np4+|Np3+ redox couple (Edeg' = 0.45 V vs. Ag|Ag+) with a solution of concentration as low as ∼0.1 mM. This result agreed well with the value (Edeg' = 0.42 V vs. Ag|Ag+) determined by cyclic voltammetry with a ∼15 mM solution. (author)

  20. Development of high temperature transport technology for LiCl-KCl eutectic salt in pyroprocessing

    Lee, Sung Ho; Lee, Hansoo; Kim, In Tae; Kim, Jeong-Guk [Korea Atomic Energy Research Institute, 1045 Daedeok-daaro, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

    2013-07-01

    The development of high-temperature transport technologies for molten salt is a prerequisite and a key issue in the industrialization of pyro-reprocessing for advanced fuel cycle scenarios. The solution of a molten salt centrifugal pump was discarded because of the high corrosion power of a high temperature molten salt, so the suction pump solution was selected. An apparatus for salt transport experiments by suction was designed and tested using LiC-KCl eutectic salt. The experimental results of lab-scale molten salt transport by suction showed a 99.5% transport rate (ratio of transported salt to total salt) under a vacuum range of 100 mtorr - 10 torr at 500 Celsius degrees. The suction system has been integrated to the PRIDE (pyroprocessing integrated inactive demonstration) facility that is a demonstrator using non-irradiated materials (natural uranium and surrogate materials). The performance of the suction pump for the transport of molten salts has been confirmed.

  1. Electro separation of an actinide using Al cathodes in LiCl-KCl

    In this work, the reprocessing of a simulated spent fuel (U60Pu20Zr10Am2Nd3.5Y0.5Ce0.5Gd0.5) has been studied by electrolysis in molten chloride salt on a solid Al cathode. The electrorefining was carried out under constant current at 733 K in LiCl-KCl eutectic. The obtained deposits were dissolved in HNO3 (7 M) and analysed by ICP-MS. The deposits were found to be composed mainly of U, Pu and Am. The U/Nd, Pu/Nd and Am/Nd ratios in the deposits were higher than 2000, 990 and 55, respectively. Therefore excellent separation of U and Pu from Ln was obtained and a separation of MA from Ln seems to be possible even with a low initial Am/Nd concentration ratio (0.41) in the salt phase. (authors)

  2. Selective Reduction of Active Metal Chlorides from Molten LiCl-KCl using Lithium Drawdown

    Michael F. Simpson; Daniel LaBrier; Michael Lineberry; Tae-Sic Yoo

    2012-10-01

    In support of optimizing electrorefining technology for treating spent nuclear fuel, lithium drawdown has been investigated for separating actinides from molten salt electrolyte. Drawdown reaction selectivity is a major issue that needs to be investigated, since the goal is to remove actinides while leaving the fission products in the salt. A series of lithium drawdown tests with surrogate fission product chlorides was run to obtain selectivity data with non-radioactive salts, develop a predictive model, and draw conclusions about the viability of using this process with actinide-loadd salt. Results of tests with CsCl, LaCl3, CeCl3, and NdCl3 are reported here. An equilibrium model has been formulated and fit to the experimental data. Excellent fits to the data were achieved. Based on analysis and results obtained to date, it is concluded that clean separation between minor actinides and lanthanides will be difficult to achieve using lithium drawdown.

  3. 用加速量热仪研究KClO3/CuO/S/MgAl/C6Cl6的热分解%Investigation of Thermal Decomposition of KClO3/CuO/S/Mg-Al/C6Cl6 System by Accelerating Rate Calorimeter

    钱新明; 王耘; 冯长根; 郑娆

    2001-01-01

    The thermal decompositions of two systems(No.1,KClO3(52.2%)/CuO(26.0%)/S(9.6%)/Mg-Al(3.5%)/C6Cl6(4.35%) and No.2,KClO3(52.2%)/CuO(26.0%)/S(9.6%)/Mg-Al(3.5%)/C6Cl6(4.35%) are studied using Accelerating Rate Calorimeter (ARC). Temperature vs time curve and pressure vs time curve of reactions are shown in Fig.1 and Fig.2 respectively. The basic data including reaction time(1.3 and 7.3 min respectively), initial temperature(159 and 150 ℃ respectively),temperature at the maximum rate(272 and 272 ℃ respectively), the maximum pressure(420 and 190 kPa respectively) and the activation energies(175.6 and 135.2 kJ· mol- 1 respectively) of the thermal decomposition are given to evaluate the safety of the two systems. Results indicate that system No.2 is safer than system No.1. Compared with the traditional methods, ARC technique can be used to measure temperature and pressure of exothermic reaction concurrently, to find the tiny exothermicity and to determine the initial temperature of exothermic reaction.

  4. An investigation of ruthenium coating from LiCl–KCl eutectic melt

    Graphical abstract: - Highlights: • A white/gray Ru coating was achieved via electrodeposition from LiCl–KCl melt. • Cathodic current efficiency (η) was increased as high as 99.68%. • A dense and 8.5 μm thick Ru coating was possible to be grown after 2 h. • “Faceted structure” was observed on the surface of Ru deposited at 3 and 7 mA/cm2. • The thickness of Ru increased with increasing both current density and time. - Abstract: In this study, electrodeposition of ruthenium (Ru) from LiCl–KCl eutectic melt was investigated in a systematic manner and the effects of process parameters namely current density, time and agitation of electrolyte on the thickness and morphology of Ru layer were explored. The presence of Ru on graphite substrates was confirmed by thin film X-ray diffraction method. The Ru coatings formed at all electrodeposition conditions appeared as a white/gray deposit. The typical “faceted structure” was observed on the surface of Ru deposited at 3 and 7 mA/cm2. Fracture cross-section examinations revealed the columnar morphology of Ru which was twinned with boundaries. The smooth appearance of Ru coating became uneven and rough with coarse nodules at 12 mA/cm2. The thickness of Ru increased with increasing both current density and time at stationary electrodeposition conditions. A dense and 7.5 μm thick Ru coating was possible to grow on graphite without any agitation at 3 mA/cm2 for 2 h. The highest cathodic current efficiency (η), 99.68%, was achieved at 3 mA/cm2 after 2 h of electrodeposition time with the rotating cathode speed of 50 rpm. The cross sectional micro-indentation studies indicated that the Ru layer has hardness as high as 450 ± 10 HV

  5. Study of thermodynamic properties of Pu-Al alloys in eutectic LiCl-KCl

    Pyrochemical separation processes are considered as a promising alternative to the hydrometallurgical methods. A technique developed in ITU is based on electrochemical reduction of actinides on an Al cathode in molten salts. This work is focused on chemical characterisation and determination of thermodynamic properties of Pu-Al alloys. The alloys are formed on a solid Al electrode during Pu electrodeposition in molten LiCl-KCl Eutectic. A carbo-chlorination was applied to convert PuO2 added to the molten salt in order to produce a LiCl-KCl-PuCl3 (∼2 wt.%). It was proven, by electrochemical measurements, that the salt contained pure PuCl3 without impurities. Pu-Al alloy properties were studied in the temperature range of 400 - 550 deg. C by electrochemical techniques. Cyclic voltammetry showed one reduction step of Pu3+ on inert W electrode (Pu3+/Pu0). On reactive aluminium electrode, reduction of Pu3+ to Pu0 occurs at more positive potential due to the formation of Pu-Al intermetallic compounds. Open Circuit Potentiometric (OCP) measurements, after depositions of Pu metal onto the Al electrode by short galvanic electrolysis, were used to identify Pu-Al intermetallic compounds. The curves obtained after OCP measurements exhibits 6 plateaus which is in agreement with the Pu-Al phase diagram, containing 5 compounds stable at working temperature range. The thermodynamic properties of the Pu-Al alloys (ΔG, ΔH, ΔS) were deduced from those curves by e.m.f. measurements. Pu-Al deposits were obtained by galvano-static electrolyses on Al plates. XRD and SEM analysis revealed a mixture of PuAl3 and PuAl4 alloys. (authors)

  6. An investigation of ruthenium coating from LiCl–KCl eutectic melt

    Kartal Sireli, G., E-mail: kartalgu@itu.edu.tr

    2014-10-30

    Graphical abstract: - Highlights: • A white/gray Ru coating was achieved via electrodeposition from LiCl–KCl melt. • Cathodic current efficiency (η) was increased as high as 99.68%. • A dense and 8.5 μm thick Ru coating was possible to be grown after 2 h. • “Faceted structure” was observed on the surface of Ru deposited at 3 and 7 mA/cm{sup 2}. • The thickness of Ru increased with increasing both current density and time. - Abstract: In this study, electrodeposition of ruthenium (Ru) from LiCl–KCl eutectic melt was investigated in a systematic manner and the effects of process parameters namely current density, time and agitation of electrolyte on the thickness and morphology of Ru layer were explored. The presence of Ru on graphite substrates was confirmed by thin film X-ray diffraction method. The Ru coatings formed at all electrodeposition conditions appeared as a white/gray deposit. The typical “faceted structure” was observed on the surface of Ru deposited at 3 and 7 mA/cm{sup 2}. Fracture cross-section examinations revealed the columnar morphology of Ru which was twinned with boundaries. The smooth appearance of Ru coating became uneven and rough with coarse nodules at 12 mA/cm{sup 2}. The thickness of Ru increased with increasing both current density and time at stationary electrodeposition conditions. A dense and 7.5 μm thick Ru coating was possible to grow on graphite without any agitation at 3 mA/cm{sup 2} for 2 h. The highest cathodic current efficiency (η), 99.68%, was achieved at 3 mA/cm{sup 2} after 2 h of electrodeposition time with the rotating cathode speed of 50 rpm. The cross sectional micro-indentation studies indicated that the Ru layer has hardness as high as 450 ± 10 HV.

  7. Analysis of ileal sodium/bile acid cotransporter and related nuclear receptor genes in a family with multiple cases of idiopathic bile acid malabsorption

    Marco Montagnani; Anna Abrahamsson; Cecilia G(a)lman; G(o)sta Eggertsen; Hanns-Ulrich Marschall; Elisa Ravaioli; Curt Einarsson; Paul A Dawson

    2006-01-01

    The etiology of most cases of idiopathic bile acid malabsorption (TBAM) is unknown. Tn this study, a Swedish family with bile acid malabsorption in three consecutive generations was screened for mutations in the ileal apical sodium-bile acid cotransporter gene (ASBT; gene symbol, SLC10A2) and in the genes for several of the nuclear receptors known to be important for ASBT expression: the farnesoid X receptor (FXR)and peroxisome proliferator activated receptor alpha (PPARα). The patients presented with a clinical history of idiopathic chronic watery diarrhea, which was responsive to cholestyramine treatment and consistent with IBAM. Bile acid absorption was determined using 75Se-homocholic acid taurine(SeHCAT); bile acid synthesis was estimated by measuring the plasma levels of 7α-hydroxy-4-cholesten-3-one (C4). The ASBT,FXR, and PPARα genes in the affected and unaffected family members were analyzed using single stranded conformation polymorphism (SSCP), denaturing HPLC,and direct sequencing. No ASBT mutations were identified and the ASBT gene did not segregate with the bile acid malabsorption phenotype. Similarly, no mutations or polymorphisms were identified in the FXR or PPARα genes associated with the bile acid malabsorption phenotype. These studies indicate that the intestinal bile acid malabsorption in these patients cannot be attributed to defects in ASBT. In the absence of apparent ileal disease, alternative explanations such as accelerated transit through the small intestine may be responsible for the IBAM.

  8. Novel roles of the Na+/H+ exchanger NHE1 and the Na+,HCO3 - cotransporter NBCn1 in cell survival, proliferation and motility

    Thorup, Gitte Ehrenreich

    cell motility. The molecular mechanisms contributing to altered pHi regulation in cancer cells are incomplete understood. Overexpression of ErbB2 is common in breast cancer and the expression of an N-terminally truncated, constitutively active ErbB2 receptor (ΔNErbB2) is associated with increased...... glycolysis, malignancy and poor prognosis. This thesis focuses on the regulation and roles of two pH regulatory transporters, the Na+/H+ exchanger NHE1 (SLC9A1) and the Na+,HCO3 - cotransporter NBCn1 (SLC4A7) in MCF-7 breast cancer cells expressing ΔNErbB2. Specifically, how these transporters contribute to....... Pharmacological inhibition of NHE1 enhances cisdiamminedichloroplatinum (II) (cisplatin) induced cell death, especially in ΔNErbB2 expressing cells. In Paper III we show that upon cisplatin treatment, expression of ΔNErbB2 results in increased caspase-9 and -7 cleavage, which is further augmented by specific...

  9. The influence of oxide on the electrochemical processes in K2NbF7-NaCl-KCl melts

    Lantelme, F.; Berghoute, Y.; Barner, Jens H. Von;

    1995-01-01

    Transient electrochemical techniques showed that in NaCl-KCl melts the reduction of K2NbF7 occurs through atwo-step reaction Nb(V) --> Nb(IV) --> Nb. When oxide ions were introduced, cyclic voltammetry indicated that the wavescorresponding to reduction of the complex NbF72- progressively disappea...

  10. Thermodynamic description of the AgCl–CoCl2–InCl3–KCl system

    The present investigation is aimed at deriving a set of self-consistent thermodynamic functions for the AgCl–CoCl2–InCl3–KCl quaternary system within the framework of the CALPHAD approach. All the previous reported thermodynamic parameters for the binary subsystems were initially reviewed and adopted, and critical thermodynamic evaluations and optimizations were later performed on the unavailable AgCl–KCl and InCl3–KCl systems in terms of the required phase equilibria and thermochemical data from experimental measurements and theoretical predictions (First-principles method and empirical equation). The Modified Quasi-Chemical model were applied to describing the molten salt phase, while all the intermediate phases were treated as the stoichiometric compounds due to no observation of the homogeneity composition range. Various phase equilibria and thermodynamic properties in the ternary and quaternary systems could be facilely calculated based upon the ultimate thermodynamic database established in this case, which will support beneficial instructions in the related industrial processes. - Highlights: • The modified quasi-chemical model was used to describe the liquid phase. • First principles method was applied to assist model parameters optimization of the intermediate phase. • The complete phase diagram of the InCl3–KCl system was calculated for the first time in the present work