Membranes image potential

The specific nature of ion binding onto the charged membrane surface may be analyzed in terms of this micropotential, image potential, the size of... 

Membrane imaging techniques based on the measurement of the local solution conductivity using scanning ion conductance microscopes (SICM) have also been reported by Burnette and Ongpipattanakul, by Hansma et al., ° and more quantitatively by Baker group. A unique advantage of SECM relative to SICM is that the individual fluxes of different chemical species in a multicomponent solution may be determined by adjusting the electrochemical potential of the SECM tip to a value where the electroactive species of interest is reduced or oxidized. Since different chemical species have different electrochemical reduction potentials, it is possible to analyze for the individual membrane fluxes of several electroactive species in the same experiment. In addition, the use of selective SECM tips extends the SECM capabilities to the detection of fluxes of nonelectroactive species. 

In other areas, POD has been used to improve the wear resistance of a mbber latex binder by incorporation of 25% of Oksalon fibers. Heat-resistant laminate films, made by coating a polyester film with POD, have been used as electrical insulators and show good resistance to abrasion and are capable of 126% elongation. In some instances, thin sheets of PODs have been used as mold release agents. For this appHcation a resin is placed between the two sheets of POD, which is then pressed in a mold, and the sheets simply peel off from the object and mold after the resin has cured. POD-based membranes exhibit salt rejection properties and hence find potential as reverse osmosis membranes in the purification of seawater. PODs have also been used in the manufacturing of electrophotographic plates as binders between the toner and plate. These improved binders produce sharper images than were possible before. 

An inhibitory input increases the influx of Cl to make the inside of the neuron more negative. This hyperpolarisation, the inhibitory postsynaptic potential (IPSP), takes the membrane potential further away from threshold and firing. It is the mirror-image of the EPSP and will reduce the chance of an EPSP reaching threshold voltage. 

Koryta et al. [48] first stressed the relevance of adsorbed phospholipid monolayers at the ITIES for clarification of biological membrane phenomena. Girault and Schiffrin [49] first attempted to characterize quantitatively the monolayers of phosphatidylcholine and phos-phatidylethanolamine at the ideally polarized water-1,2-dichloroethane interface with electrocapillary measurements. The results obtained indicate the importance of the surface pH in the ionization of the amino group of phosphatidylethanolamine. Kakiuchi et al. [50] used the video-image method to study the conditions for obtaining electrocapillary curves of the dilauroylphosphatidylcholine monolayer formed on the ideally polarized water-nitrobenzene interface. This phospholipid was found to lower markedly the surface tension by forming a stable monolayer when the interface was polarized so that the aqueous phase had a negative potential with respect to the nitrobenzene phase [50,51] (cf. Fig. 5). 

Dialkylanthracene-containing squaraine dyes 17 show intense absorption and emission in the NIR region (720-810 nm) [74]. They are compatible with aqueous environments and show substantial enhancement of quantum yields and fluorescence lifetimes in hydrophobic and micellar media, suggesting that these dyes can be potentially useful as fluorescent probes in biological applications, e.g., for imaging of hydrophobic domains such as cell membranes. 

Zochowski M, Wachowiak M, Falk CX et al (2000) Imaging membrane potential with voltage-sensitive dyes. Biol Bull 198 1-21... 

Shynkar VV, Klymchenko AS, Duportial G et al (2005) Two-colour fluorescent probes for imaging the dipole potential of cell plasma membranes. Biochim Biophys Acta Biomem 1712 128-136... 

Membrane Potential-Sensitive Aggregates of the Dyes JC-1 and JC-9 for Mitochondria Imaging... 

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