scholarly journals High-capacity hydrogen release through hydrolysis of NaB3H8

2011 ◽  
Vol 36 (12) ◽  
pp. 7038-7042 ◽  
Author(s):  
Zhenguo Huang ◽  
Xuenian Chen ◽  
Teshome Yisgedu ◽  
Ji-Cheng Zhao ◽  
Sheldon G. Shore
Keyword(s):  
High Capacity ◽  
Hydrogen Release ◽  
Hydrolysis Of

Inhibition of proximal tubular hydrolysis and reabsorption of bradykinin by peptides

1976 ◽  
Vol 231 (3) ◽  
pp. 743-748 ◽  
Author(s):  
S Oparil ◽  
FA Carone ◽  
TN Pullman ◽  
S Nakamura
Keyword(s):  
Enzymatic Hydrolysis ◽  
High Capacity ◽  
High Specificity ◽  
Proximal Tubules ◽  
Enzymatic Cleavage ◽  
Angiotensin I ◽  
Urinary Recovery ◽  
Proximal Tubular ◽  
Hydrolysis Of ◽  
Fold Excess

[3H] bradykinin ([3H] BKN) was microinfused alone or in the presence of a 390- or 780-fold excess of BKN or angiotensin I (AI) into proximal tubules in Inactin-anesthetized rats. Urinary excretion of 3H-labeled material was measured, and intact peptide and its metabolites were identified and quantified. When [3H] BKN was administered with BKN or AI, urinary recovery of 3H-labeled material was increased in a manner directly proportional to tubular length, suggesting that reabsorption of [3H] BKN is related to extent of tubular contact. BKN and AI were equally effective in inhibiting the reabosroption of [3H] BKN and its metabolites from proximal tubular fluid. In contrast, BKN but not AI effectively inhibited the enzymatic hydrolysis of [3H] BKN in the proximal tubule, The data suggest that the proximal tubular mechanism for reabsorbing BKN and its metabolites is of high capacity but not high specificity and that the mechanisms for enzymatic cleavage and reabsorption of BKN and its metabolites may had different specificites and capacities.

Hydrogen generation by both acidic and catalytic hydrolysis of sodium borohydride

2018 ◽  
Vol 5 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Olga V. Netskina ◽  
Tihon N. Filippov ◽  
Oksana V. Komova ◽  
Valentina I. Simagina
Keyword(s):  
Hydrogen Evolution ◽  
Sodium Borohydride ◽  
Hydrogen Generation ◽  
Hydrogen Release ◽  
Catalytic Hydrolysis ◽  
Hydrogen Storage Materials ◽  
Acidic Solutions ◽  
High Concentrations ◽  
Sulfuric And Hydrochloric Acids ◽  
Hydrolysis Of

Abstract Sodium borohydride tablets have been employed as hydrogen-storage materials. Hydrogen release was performed by acidic hydrolysis where solutions of sulfuric and hydrochloric acids were added to the tablets, and by catalytic hydrolysis where water was added tablets of solid-state NaBH4/Co composite. In acidic solutions hydrogen evolution occurred instantaneously, and at high concentrations of acids the releasing hydrogen contained an admixture of diborane. Hydrogen evolution from the solidstate NaBH4/Co composite proceeded at a uniform rate of 13.8±0.1 cm3·min-1, water vapor being the only impurity in the evolving gas.

Time course and vectorial nature of albumin metabolism in isolated perfused rabbit PCT

1988 ◽  
Vol 255 (3) ◽  
pp. F520-F528 ◽  
Author(s):  
C. H. Park
Keyword(s):  
Time Course ◽  
Hydrolysis Product ◽  
High Capacity ◽  
Intact Protein ◽  
Renal Metabolism ◽  
First Order ◽  
First Order Kinetics ◽  
Hydrolysis Products ◽  
Renal Tubular ◽  
Hydrolysis Of

The time course and vectorial nature of renal metabolism of albumin (Alb) were studied. The tubular absorption, accumulation, and hydrolysis of Alb and the release of the hydrolysis products were determined in the isolated rabbit proximal convoluted tubule (PCT) perfused with tritiated Alb ([3H3C]Alb) at 36.4 micrograms/ml. The Alb absorption across the apical membrane was constant (99.9 +/- 4.9 x 10(-3) ng.min-1.mm-1). In contrast, the accumulation and hydrolysis of Alb in the cells increased nonlinearly with time. The bulk of the tritium that accumulated in the cells was associated with intact [3H3C]Alb. Only the final hydrolysis products were released from the cells and these first appeared in the peritubular bath 6–7 min after the start of perfusion of the tubule with [3H3C]Alb. The hydrolysis product was not detectable in the tubule lumen. The proteolytic activity correlated linearly with the protein load to the cells, characteristic of first-order kinetics and a high-capacity system. The results suggest that the renal tubular handling of proteins proceeds from the apical to the basolateral aspect of the cell. The transcellular processing of Alb is rapid and can occur in 6–7 min. The accumulation of intact protein in the cell and the first-order kinetics of hydrolysis of the absorbed protein suggest that the rate-limiting step in proximal tubular handling of proteins may include the initial hydrolysis of protein or reside in steps that precede the hydrolysis.

Copper-cobalt foams as active and stable catalysts for hydrogen release by hydrolysis of sodium borohydride

2016 ◽  
Vol 41 (20) ◽  
pp. 8438-8448 ◽  
Author(s):  
Sónia Eugénio ◽  
Umit B. Demirci ◽  
Teresa Moura Silva ◽  
Maria João Carmezim ◽  
Maria Fátima Montemor
Keyword(s):  
Sodium Borohydride ◽  
Hydrogen Release ◽  
Hydrolysis Of

In situ synthesis of GeO2/reduced graphene oxide composite on Ni foam substrate as a binder-free anode for high-capacity lithium-ion batteries

2015 ◽  
Vol 3 (4) ◽  
pp. 1619-1623 ◽  
Author(s):  
Heyuan Qiu ◽  
Lingxing Zeng ◽  
Tongbin Lan ◽  
Xiaokun Ding ◽  
Mingdeng Wei
Keyword(s):  
High Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Cycling Performance ◽  
Dip Coating ◽  
Reduced Graphene ◽  
Binder Free ◽  
Hydrolysis Of

The GeO2/RGO electrode is successfully fabricated via a facile dip-coating route cooperated with in situ hydrolysis of GeCl4 and used directly as a binder-free anode for LIBs. This material exhibited high reversible capacity, good cycling performance and excellent rate capability.

Transport and hydrolysis of glucagon in the proximal nephron

1986 ◽  
Vol 251 (3) ◽  
pp. F460-F467 ◽  
Author(s):  
D. R. Peterson ◽  
E. A. Green ◽  
S. Oparil ◽  
J. T. Hjelle
Keyword(s):  
Proximal Tubule ◽  
Brush Border ◽  
High Capacity ◽  
Cell Fractionation ◽  
Bathing Medium ◽  
Proximal Tubule Cells ◽  
Large Peak ◽  
Hydrolysis Of ◽  
Contraluminal Membrane

Transport and hydrolysis of glucagon in the rabbit proximal nephron were studied. Iodinated glucagon (0.34 +/- 0.02 pg/nl, mean +/- SE) was microperfused (16.0 +/- 1.1 nl/min) in vitro through proximal straight nephron segments for 30 min. Radiolabeled material, primarily 125I-tyrosine, appeared in the bathing medium in a linear fashion as a function of time (0.406 pg glucagon X mm tubule length-1 X min-1). Hydrolysis of glucagon by proximal tubule homogenates was pH dependent, with a large peak of activity observed at pH 7.0-7.4 and a smaller one at pH 3.0. Analytical cell fractionation studies of proximal tubule cells revealed glucagon-hydrolyzing activity associated with the brush border and cytosol at pH 7.4. Less than 3% of activity was found associated with the contraluminal membrane. Substantial catabolism was observed at lysosomes on lowering the pH to 5.0. Incubation of glucagon directly in the presence of isolated renal cortical microvilli confirmed the presence of a high-capacity glucagon-degrading hydrolase. In addition to glucagon-hydrolyzing activity associated with the proximal nephron, noncortical activity was observed that was not accounted for by proximal tubule hydrolases. The data suggest several mechanisms for renal extraction of glucagon, including hydrolysis by enzymes at the brush border of the proximal tubule, prior to reabsorption of metabolites there. Conversely, enzymes associated with the contraluminal membrane of the proximal nephron probably contribute little to its hydrolysis. Nonproximal extracortical degradation of glucagon may account for its previously observed peritubular hydrolysis.

Renal hydrolysis of absorbed protein: influence of load and lysosomal pH

1984 ◽  
Vol 247 (4) ◽  
pp. F656-F664 ◽  
Author(s):  
M. J. Camargo ◽  
B. E. Sumpio ◽  
T. Maack
Keyword(s):  
Rat Kidney ◽  
High Capacity ◽  
Lysosomal Ph ◽  
Renal Tubular Cells ◽  
Weak Bases ◽  
Uptake Rates ◽  
Cyt C ◽  
Renal Tubular ◽  
Hydrolysis Of

The kinetics of intracellular hydrolysis of administered protein and the effect of alkalinization of lysosomal pH on this process were studied in the isolated perfused rat kidney (IPK). Cytochrome c (CYT c) was used as a probe protein, and its hydrolysis was determined by measuring the efflux of radioactivity from IPK preloaded in vivo with [14CH3]CYT c and various doses of unlabeled CYT c. The nature of radioactivity absorbed by the kidney and released to the perfusate was analyzed by Sephadex chromatography. Administered CYT c is absorbed and hydrolyzed by the kidney, and the resulting amino acids are returned to the perfusate. At low uptake rates, the half time of hydrolysis of absorbed CYT c is about 20 min. The disposal of absorbed CYT c is a saturable function of its concentration in kidney with a Vmax = 0.60 mg CYT c X h-1 X g kidney-1 and an apparent Km = 0.55 mg CYT c/g kidney. To alkalinize the lysosomal pH, IPK were perfused in the presence of NH4Cl (10 mM) or chloroquine (0.1 mM). These lysosomotropic weak bases almost completely inhibit in a reversible manner the hydrolysis of absorbed CYT c. The results demonstrate that renal catabolism of absorbed protein is a saturable process of high capacity compared with the normal filtered loads of protein. The data are consistent with the view that normal lysosomal function is required for an adequate disposal of absorbed proteins in the kidney. It is postulated that abnormal deposition of protein absorption droplets within renal tubular cells may result from high absorbed loads and/or a deficient acidification of lysosomes.

Demonstration of Controlled Hydrogen Release Using Rh@GQDs during Hydrolysis of NH3BH3

2021 ◽  
Author(s):  
Weifeng Chen ◽  
Guo Lv ◽  
Jinrun Fu ◽  
Haiyan Ren ◽  
Jialu Shen ◽  
...  
Keyword(s):  
Hydrogen Release ◽  
Hydrolysis Of

Promoted hydrogen release from alkali metal borohydrides in ionic liquids

2016 ◽  
Vol 3 (9) ◽  
pp. 1137-1145 ◽  
Author(s):  
He Fu ◽  
Yong Wu ◽  
Jun Chen ◽  
Xiaojuan Wang ◽  
Jie Zheng ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Low Temperature ◽  
Alkali Metal ◽  
High Capacity ◽  
Hydrogen Release

Low-temperature high capacity dehydrogenation is found in MBH4-IL (M = Na, Li) systems.

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