ATP ↔Pi exchange and membrane phosphorylation in sarcoplasmic reticulum vesicles. Activation by silver in the absence of Ca2+ ion concentration gradient

Biochemistry ◽  
1975 ◽  
Vol 14 (12) ◽  
pp. 2739-2744 ◽  
Author(s):  
Leopoldo De Meis ◽  
Martha M. Sorenson
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Concentration Gradient ◽  
Ion Concentration ◽  
Membrane Phosphorylation

THE EFFECTS OF ELASTIC STIFFENING ON THE EVOLUTION OF THE STRESS FIELD WITHIN A SPHERICAL ELECTRODE PARTICLE OF LITHIUM-ION BATTERIES

2013 ◽  
Vol 05 (04) ◽  
pp. 1350040 ◽  
Author(s):  
WENBIN ZHOU ◽  
FENG HAO ◽  
DAINING FANG
Keyword(s):  
Stress Field ◽  
Lithium Ion Batteries ◽  
Internal Stress ◽  
Concentration Gradient ◽  
Concentration Field ◽  
Lithium Ion ◽  
Coupling Model ◽  
Ion Concentration ◽  
Hysteresis Phenomenon ◽  
Mechanical Coupling

Poor cyclic performance of lithium-ion batteries is calling for efforts to study its capacity attenuation mechanism. The internal stress field produced in the lithium-ion battery during its charging and discharging process is a major factor for its capacity attenuation, research on it appears especially important. We established an electrochemical –mechanical coupling model with the consideration of the influence of elastic stiffening on diffusion for graphite anode materials. The results show that the inner stress field strongly depends on the lithium-ion concentration field, greater concentration gradients lead to greater stresses. The evolution of the stress field is similar to that of the concentration gradient but lags behind it, which shows hysteresis phenomenon. Elastic stiffening can lower the concentration gradient and increase elastic modulus, which are two major factors influencing the inner stress field. We conclude that the latter is more dominant compared to the former, and elastic stiffening acts to increasing the internal stress.

scholarly journals A sodium ion concentration gradient formed during the absorption of glycine by mouse ascites-tumour cells

1969 ◽  
Vol 115 (3) ◽  
pp. 505-509 ◽  
Author(s):  
A A Eddy
Keyword(s):  
Concentration Gradient ◽  
Ringer Solution ◽  
Sodium Cyanide ◽  
Tumour Cells ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Carrier System ◽  
Parallel Movement ◽  
Mouse Ascites ◽  
Ascites Tumour Cells

1. To deplete them of ATP the tumour cells were starved at 37° in a Ringer solution containing 33m-equiv. of Na+/l., 131m-equiv. of Li+/l., 2mM-sodium cyanide and 0·1mm-ouabain. The cellular content of K+ was largely replaced by Li+, but cellular [Na+] remained near 33m-equiv./l. 2. The addition of 12mm-glycine to the system caused cellular [Na+] to increase, during the next 4min., by about 4m-equiv./l., so that it slightly exceeded extracellular [Na+]. This occurred in parallel with the absorption of glycine. 3. The cellular K+ content fell by an amount representing about 10% of the amount of Na+ absorbed. 4. The results provide a clear demonstration that the flow of glycine into the cells is linked to a parallel movement of Na+; K+ appears to play a facultative role in the carrier system, whereas Li+ is almost inert. 5. The effects produced by glycine were not reproduced by l-arabinose.

Effect of strophanthidin on the renal tubules of dogs

1961 ◽  
Vol 200 (2) ◽  
pp. 373-379 ◽  
Author(s):  
J. R. Cade ◽  
R. J. Shalhoub ◽  
M. Canessa-Fischer ◽  
R. F. Pitts
Keyword(s):  
Glomerular Filtration Rate ◽  
Concentration Gradient ◽  
Filtration Rate ◽  
Intact Animal ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Renal Tubules ◽  
Luminal Surface ◽  
Potassium Salts ◽  
Hydrogen Ion Concentration

The nature and mechanism of the diuresis produced in the dog by strophanthidin was investigated by infusion of the drug into one renal artery. Saline-loaded dogs respond to strophanthidin infusion with a prompt fall in glomerular filtration rate (GFR) and a delayed saluresis and diuresis. The effect on electrolyte transport can be blocked by loading with potassium salts but the fall in GFR can be only partially prevented. Strophanthidin given to adrenalectomized dogs produces the same effect as in the intact animal. The ability to maintain a steep transtubular hydrogen ion concentration gradient is severely impaired. The data are best interpreted as inhibition of the potassium arm of a linked Na-K exchange across the peritubular cell membrane, with diuresis occurring secondary to this block. Impairment of the ability to maintain a steep hydrogen ion concentration gradient indicates an additional effect on linked exchange occurring at the luminal surface of the cell.

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