Cells electrical field effects

Fluorescence Lifetime Imaging Study on Living Cells with Particular Regard to Electric Field Effects and pH Dependence 607... 

The molecular lever mechanisms that permit muscle function to directly regulate the genomic activity of strained bone cells, including their phenotypic expression, when combined together with electric field effects and contraction frequency energetics, provides a biophysical basis for an earlier hypothesis of epigenetic regulation of skeletal tissue adaptation [135, 136, 146, 147]. 

Geveke, D.J. and Kozempel, M.F. 2003. Pulsed electric field effects on bacteria and yeast cells. Journal of Food Processing and Preservation 27 65-72. 

Hiilsheger, H., Potel, J., and Niemann, E.G. 1983. Electric field effects on bacteria and yeast cells. Radiation and Environmental Biophysics 22 149-162. 

Studies of electrochemical reactions of redox proteins have attracted widespread interest and attention. Such studies can yield important information about not only intrinsic thermodynamic and kinetic properties of redox proteins, but also structural properties, such as binding characteristics of proteins at specific types of electrode surfaces and the orientational requirements for electron transfer between the protein and the electrode. The results are useful for the development of biosensors, biofuel cells, and biocatalysts. In addition, the information obtained from these studies can contribute to an understanding of the physiological implications of biological electron transfer reactions, because many electron transfer proteins are located at, or close to, charged membranes and are thus subject to large electric field effects that are similar to those near an electrode surface. 

Pliquett U, Joshi RP, Sridhara V, Schoenbach KH. 2007. High electric field effects on cell membranes. 

Electric field effects play an important role in many biological cell processes. Phenomena as different as nerve excitation, electrogenic ion transport, neurostimulated secretion of hormones and transmitter substances, or the photosynthesis of involve cell functions in which... 

After the preparation of this review further progress in the physical chemical analysis of electric field effects in biological macromolecules and in the membranes of isolated cells and organelleshas been documented. A few additional references are selected. 

Phquett, U, R.R Jodii, V. Sridhara, and K.H. Schoenbach (2007). High electrical field effects on cell membranes. Bioelectrochemistry 70(2), 275-282. 

E. Jacob, W. Forster, and H. Berg, Microbiological implications of electric field effects. II. Inactivation of yeast cells and repair of their cell envelope, Z.Allgem.Mikrobiol., 21 225-233 (1981). Senda, J. Takedo, Sh. Abe, and T. Nakamura, Induction of cell fusion of plant protoplasts by electrical stimulation. Plant Cell Physiol., 20 144 (1979). 

The spatial variation on the electrode of current density i is often referred to as the current distribution. Since the current density is related to reactirai rate through Faraday s law, the current distribution is thus a manner of expressing the variation of reaction rate within an electrochemical cell. As for traditional chemical reactors, nonuniformities in reaction rate may be anticipated if the fluid flow is inadequate to prevent concentration gradients. However, electrical field effects also influence the current distribution in an electrochemical cell, and thus reaction rates can be nonuniform even if perfect mixing is achieved in the reactor. Electrochemical cells of course have two electrodes, and sometimes optimizing a current distribution of one electrode is more important than the other. Depending on the proximity of the two electrodes, the current distributions of the electrodes may or may not influence each other. 

For the scale up of a chemical reactor, inadequate mixing may result in spatial variations in, for example, reactant composition or temperature. An electrochemical reactor (cell) is a chemical reactor where the reduction and oxidation reactions are spatially separated on cathodes and anodes. The flow of ionic current through the electrolyte results in an electric field through the electrolyte. Since charged species move in response to an electrical field [1-3] and since the potential difference across the double layer impacts reaction rate, electrical field effects can significantly impact current distribution. Thus, in contrast to a chemical reactor, perfect mixing to eliminate all concentration fields does not necessarily result in uniform reaction rates. 

Electrical field effects are an example of a transport phenomenon that does not arise in most chemical reactors, and these field effects often dictate the current distribution. Usually, electrical field effects are more important in the (ionicaUy conducting) electrolyte than in the (electronically conducting) electrodes. However, as is the case of porous electrodes for fuel cells and batteries, significant potential variations in the electrodes may result if the electrodes are very thin, very large, or have high specific resistivity. Current distributions where the potential drop in the electrode is important were first studied in 1953 [4] the phenomenon is called the terminal effect or resistive substrate effect. ... 

Order of magnitude estimates of dimensionless groups may provide a sound basis to determine whether nonuniformities are anticipated and whether concentration or electrical field effects are the primary consideration. These dimensionless groups have well-understood physical meaning and are discussed below. Similar concepts emerge in the analysis and design of porous electrodes that may be used in a battery or fuel cell. 

The corresponding atomistic kinetics is then implemented into the nonequilibrium nanoscale MEMEPhys models collecting all the elementary events, catalytic and no-catalytic, to simulate the electrochemical observables. The nanoscale models introduce the electric field effect correction without empirical parameters and open interesting perspectives to scale up atomistic data into macroscopic models in a robust way. The impact of the catalyst chemistry and nanostructure on the electrodes and cell potentials can be then captured. 

Ferroelectricity in biological systems is usually referred as bioferroelectiidty. It has been widely observed in biological materials and may be common in biological cell components. Froclich has analyzed the electric field effects on biological membranes on tire dipolar properties of the proteins dissolved in them. A relation between ferroelectricity, liquid crystals, nervous and muscular impulses was predicted by von Hippel. Brain memory has been postulated to be based on a ferroelectric mechanism. Beresnev and coworkers noted the close similarity between biomembranes and ferroelectric liquid crystals, particularly the presence of a layered structure with tilted lipid and protein molecules and chiral molecules of cholesterol. The possibility of involvement of ferroelectric phenomena in membrane function was also suggested by several authors. ... 

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