Cylindrical Cell Membranes in Uniform Applied Electric Fields: Validation of a Transport Lattice Method

2005 ◽  
Vol 52 (10) ◽  
pp. 1643-1653 ◽  
Author(s):  
D.A. Stewart Jr. ◽  
T.R. Gowrishankar ◽  
K.C. Smith ◽  
J.C. Weaver
Keyword(s):  
Electric Fields ◽  
Cell Membranes ◽  
Lattice Method ◽  
Cylindrical Cell

scholarly journals Detection and processing of electromagnetic and near–field acoustic signals in elasmobranch fishes

2000 ◽  
Vol 355 (1401) ◽  
pp. 1135-1141 ◽  
Author(s):  
Ad. J. Kalmijn
Keyword(s):  
Magnetic Field ◽  
Electric Fields ◽  
Cell Membranes ◽  
Near Field ◽  
Feedback Mechanism ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field ◽  
Positive Feedback Mechanism ◽  
Elasmobranch Fishes ◽  
Physical Features

The acoustic near field of quietly moving underwater objects and the bio–electric field of aquatic animals exhibit great similarity, as both are predominantly governed by Laplace's equation. The acoustic and electrical sensory modalities thus may, in directing fishes to their prey, employ analogous processing algorithms, suggesting a common evolutionary design, founded on the salient physical features shared by the respective stimulus fields. Sharks and rays are capable of orientating to the earth's magnetic field and, hence, have a magnetic sense. The electromagnetic theory of orientation offers strong arguments for the animals using the electric fields induced by ocean currents and by their own motions in the earth's magnetic field. In the animal's frame of reference, in which the sense organs are at rest, the classical concept of motional electricity must be interpreted in relativistic terms. In the ampullae of Lorenzini, weak electric fields cause the ciliated apical receptor–cell membranes to produce graded, negative receptor currents opposite in direction to the fields applied. The observed currents form part of a positive–feedback mechanism, supporting the generation of receptor potentials much larger than the input signal. Acting across the basal cell membranes, the receptor potentials control the process of synaptic transmission.

scholarly journals Pulsed Power Applications for Protein Conformational Change and the Permeabilization of Agricultural Products

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6288
Author(s):  
Koichi Takaki ◽  
Katsuyuki Takahashi ◽  
Alexis Guionet ◽  
Takayuki Ohshima
Keyword(s):  
Power Systems ◽  
Conformational Change ◽  
Electric Fields ◽  
Food Processing ◽  
Cell Membranes ◽  
Pulsed Power ◽  
Agricultural Products ◽  
Activity Change ◽  
Protein Conformational Change ◽  
Compact Pulsed Power

Pulsed electric fields (PEFs), which are generated by pulsed power technologies, are being tested for their applicability in food processing through protein conformational change and the poration of cell membranes. In this article, enzyme activity change and the permeabilization of agricultural products using pulsed power technologies are reviewed as novel, nonthermal food processes. Compact pulsed power systems have been developed with repetitive operation and moderate output power for application in food processing. Firstly, the compact pulsed power systems for the enzyme activity change and permeabilization are outlined. Exposure to electric fields affects hydrogen bonds in the secondary and tertiary structures of proteins; as a result, the protein conformation is induced to be changed. The conformational change induces an activity change in enzymes such as α-amylase and peroxidase. Secondly, the conformational change in proteins and the induced protein functional change are reviewed. The permeabilization of agricultural products is caused through the poration of cell membranes by applying PEFs produced by pulsed discharges. The permeabilization of cell membranes can be used for the extraction of nutrients and health-promoting agents such as polyphenols and vitamins. The electrical poration can also be used as a pre-treatment for food drying and blanching processes. Finally, the permeabilization of cell membranes and its applications in food processing are reviewed.

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