Fast inactivation of the HERG potassium channel plays a critical role in normal cardiac function. Malfunction of these channels due to either genetic mutations or blockade by drugs leads to cardiac arrhythmias. An unusually long S5-P linker in the outer mouth of HERG is implicated in the fast inactivation mechanism. To examine the role of the S5-P linker in this inactivation mechanism, we study...

The viral protein U (Vpu) encoded by HIV-1 has been shown to assist in the detachment of virion particles from infected cells. Vpu forms cation-specific ion channels in host cells, and has been proposed as a potential drug target. An understanding of the mechanism of ion transport through Vpu is desirable, but remains limited because of the unavailability of an experimental structure of the cha...

The ability of biological ion channels to conduct selected ions across cell membranes is critical for the survival of both animal and bacterial cells. Numerous investigations of ion selectivity have been conducted over more than 50 years, yet the mechanisms whereby the channels select certain ions and reject others are not well understood. Here we report a new application of Jarzynski's Equalit...

In this study, the hydrogen permeation in the supercooled liquid state for Ni65Nb25Zr10, Ni60Nb20Zr20 and Ni55Nb15Zr30 metallic glasses was investigated in conjunction with the discussion on the effect of hydrogen diffusion on hydrogen permeation. The hydrogen permeation of the Ni65Nb25Zr10 and Ni60Nb20Zr20 metallic glasses increases significantly by the transition from the glassy solid state t...

The purpose of this work was to study the effect of various permeation enhancers on the permeation of salbutamol sulphate (SS) buccal patches through buccal mucosa in order to improve the bioavailability by avoiding the first pass metabolism in the liver and possibly in the gut wall and also achieve a better therapeutic effect. The influence of various permeation enhancers, such as dimethyl sul...

comnode classification within membrane residue curves (m-rcms) currently hinges on lyapunov’s theorem and therefore the computation of mathematically complex eigenvalues. this paper presents an alternative criterion for the classification of nodes within m-rcms based on the total membrane flux at node compositions. this paper demonstrates that for a system exhibiting simple permeation behaviour...

objective(s) in this study, a kind of ph sensitive composite membrane was prepared and drug permeation through it was investigated in terms of ph. rationale of this study originated from the fact that a ph change which may be a result of a disease state in the body can trigger drug release. materials and methods  here, a kind of ph sensitive composite membrane containing different nanoparticle ...

The oxygen permeation performance of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) mixed-conducting multichannel hollow fiber (MCMHF) membranes was improved by surface modification via spin-spraying of a La0.6Sr0.4CoO3−δ (LSC) porous layer. At 1173 K, the oxygen permeation flux of the modified membranes was clearly enhanced and reached 9.68 mL·cm−2·min−1, which is a remarkable high value in the field of mixe...

Abstract: The objective of this study was to fabricate topical formulations of diclofenac diethylamine (DD) using isopropyl myristate (IPM) and isopropyl palmitate (IPP) as permeation enhancers. Franz cell and bacterial cellulose were used as analytical instrument and diffusion membrane, respectively. Permeation enhancers exhibited significant effect on the permeation characteristics of DD. It ...

In this study, we provide the experimental results of binary blends a semi-flexible nematic liquid crystal polymer (LCP1) and polycarbonate (PC) within their phase diagram. The LCP1/PC were investigated by Differential Scanning Calorimetry (DSC), Optical Microscopy (OM), Wide-angle X-Ray Diffraction (WXRD), Fourier Transfer Infrared (FTIR), Gel Permeation Chromatography (GPC), Nuclear Magnetic ...