Intermolecular enol tautomers of Watson-Crick base pairs could emerge spontaneously via interbase double proton transfer. It has been hypothesized that their formation could be facilitated by thermal fluctuations and proton tunneling, and possibly be relevant to DNA damage. Theoretical and computational studies, assuming classical nuclei, have confirmed the dynamic stability of these rare tautomers.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
April 2002
A self-consistent model analysis of electroporation in biological cells has been carried out based on an improved energy model. The simple energy model used in the literature is somewhat incorrect and unphysical for a variety of reasons. Our model for the pore formation energy E(r) includes a dependence on pore population and density.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
February 2002
An electromechanical analysis based on thin-shell theory is presented to analyze cell shape changes in response to external electric fields. This approach can be extended to include osmotic-pressure changes. Our calculations demonstrate that at large fields, the spherical cell geometry can be significantly modified, and even ellipsoidal forms would be inappropriate to account for the deformation.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
July 2001
The temporal dynamics of electroporation of cells subjected to ultrashort voltage pulses are studied based on a coupled scheme involving the Laplace, Nernst-Plank, and Smoluchowski equations. A pore radius dependent energy barrier for ionic transport, accounts for cellular variations. It is shown that a finite time delay exists in pore formation, and leads to a transient overshoot of the transmembrane potential V(mem) beyond 1.
View Article and Find Full Text PDFPhys Rev B Condens Matter
March 1992
Phys Rev B Condens Matter
March 1989
Phys Rev B Condens Matter
September 1985