Results 161 to 170 of about 212,661 (192)

Membrane potentials for keratin

Journal of Colloid Science, 1947
Abstract Measurements of the membrane potentials of keratin membranes have been made using KCl and NaCl and the results show how the selectivity of the membranes can be altered by soaking in suitable buffer solutions. The results support Toerell's theory of membrane behavior in neutral salts, and some membrane potential measurements using HCl ...
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Negative membrane potentials potentiate multicellularity

BioSystems
Why did evolution almost exclusively select negative membrane potentials? Why did natural selection not favour positive membrane potentials? Further, membrane constituents are also negatively charged, in the form phospholipids. Putative cis-charge repulsion represents an obstacle to the emergency of multicellularity. This is compounded by the fact that
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Membrane potential of bipolar membranes

Journal of Electroanalytical Chemistry, 1996
Abstract The membrane potential of a bipolar membrane composed of a cation-exchange layer in series with an anion-exchange layer is analyzed theoretically and experimentally. The theoretical approach is based on an extension of the Nernst-Planck equations of monopolar charged membranes to the case of the two ion-exchange layers in series and the ...
P. Ramírez, S. Mafé, J.A. Manzanares, J. Pellicer   +3 more
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Recognition of substrates by membrane potential of immobilized enzyme membranes: membrane potential theory

Journal of the Chemical Society, Faraday Transactions, 1991
The shifts in membrane potential, caused by the injection of D-glucose into a permeation cell, were obtained theoretically from membrane potential theory and compared to experimental data measured for immobilized (entrapped) glucose oxidase membrane and its lamellar enzyme membranes.
Akon Higuchi, Shouich Chida, Tsutomu Nakagawa   +2 more
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Depolarization of the membrane potential by hyaluronan

Journal of Cellular Biochemistry, 2010
AbstractThe membrane potential is mainly maintained by the K+ concentration gradient across the cell membrane between the cytosol and the extracellular matrix. Here, we show that extracellular addition of high‐molecular weight hyaluronan depolarized the membrane potential of human fibroblasts, human embryonic kidney cells (HEK), and central nervous ...
Daniel, Hagenfeld, Tobias, Schulz, Petra, Ehling, Thomas, Budde, Udo, Schumacher, Peter, Prehm   +5 more
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Relationship of epithelial membrane potentials to corneal potential

Experimental Eye Research, 1973
Abstract The rabbit corneal potential arises as the sum of three steps across the epithelium. These occur across the squamous cell outer membrane, at the transition region between wing and basal cells, and across the basal cell inner membrane. Variations in corneal potential are inversely proportional to outer membrane potential.
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Membrane potential, surface potential and ionic permeability

Physics Letters A, 1979
To clarify contributions to cellular transmembrane potential concentration potentials of phospholipid bilayer membranes and surface potentials of phospholipid monolayers were measured with respect to salt concentrations and various surface charge densities.
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Membrane Potential and Muscle Function

Annual Review of Medicine, 1969
The relationship between the function of a whole muscle and the elec­ trical polarization of its individual fiber membranes is not a simple or direct one. To be sure, the process known as excitation-contraction coupling requires at least a minimum of fairly well-defined properties and events at the fiber surfaces, but both the resting voltages across ...
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Membrane potentials inStentor coeruleus

Protoplasma, 1971
The membrane potential ofStentor coeruleus was measured by means of glass microelectrodes. The tips of the electrodes had a diameter of 2 μ, and were filled with 0.1 M KCl. The maximum value of the potential is −30.8±8.6 mV and is reached within 600–800 msec after electrode insertion; the potential then decreases to a negative value of a few mV within ...
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Quantitative Analysis of Membrane Potentials

2009
The changes that occur in electrochemical gradients across biological membranes provide us with invaluable information on physiological responses, pathophysiological processes and drug actions/toxicity. This chapter aims to provide researchers with sufficient information to carry out a quantitative assessment of mitochondrial energetics at a single ...
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