Hydrogen bonded poly(acrylic acid) (PAA)/poly(ethylene oxide) (PEO) layer-by-layer assemblies are highly elastomeric, but more permeable than ionically bonded thin films. In order to expand the use of hydrogen-bonded assemblies to applications that require a better gas barrier, the effect of assembling pH on the oxygen permeability of PAA/PEO multilayer thin films was investigated. Altering the...

BACKGROUND The effect of non-pulsatile, normothermic cardiopulmonary-bypass (CPB) on the splanchnic blood-flow and oxygen-transport, the hepatic function and the gastrointestinal barrier were observed in a prospective observational study in 31 adults undergoing cardiac valve replacement surgery. METHODS The splanchnic (i.e. hepatic) blood-flow (HBF) was measured by the constant infusion of in...

OBJECTIVES The aim of this study was to design and evaluate a chitosan-based film that has properties required for successful wound dressing, and can control drug penetration and maintenance time in the location. METHODS Several formulations of a film containing chitosan (3%) and different concentrations of Eudragit RL (0.5%, 1%, and 1.5%) were prepared using the casting/solvent evaporating t...

Oxygen permeability and water diffusion characteristics were determined for several types of hydroxyethyl-methacrylate hydrophilic contact lenses and a silicone contact lens material. A twoto fourfold difference in the diffusion rates for capillary flow of water was found among the different hydrophilic lenses. Oxygen permeability studies demonstrate that the hydrophilic lenses are capable of t...

Oxygen transport in the Chinese hamster ovary (CHO) plasma membrane has been studied by observing the collision of molecular oxygen with nitroxide radical spin labels placed in the lipid bilayer portion of the membrane at various distances from the membrane surface using the long-pulse saturation-recovery electron spin resonance (ESR) technique. The collision rate was estimated for 5-, 12-, and...

arsenic exposure mainly through food and water has been shown to be associated with increased incidence of numerous cancers and non-cancer harmful health. it is also used in cancer chemotherapy and treatment of several cancer types due to its apoptogenic effects in the various cancer and normal cell lines. we have already reported that liver is the storage site and important target organ in as ...

improving barrier properties through the use of nanocomposites is an important area of research, especially for the food packaging industry. in this work, titanium dioxide (tio2 )/low density poly ethylene (ldpe) nanocomposites were synthesized as the oxygen barrier layers through the co-extrusion process. the oxygen permeability of the nanocomposite with 4% of tio2 decreased for about 16% comp...

Isolated brain mitochondria were examined for their responses to calcium challenges under varying conditions. Mitochondrial membrane potential was monitored by following the distribution of tetraphenylphosphonium ions in the mitochondrial suspension, mitochondrial swelling by observing absorbance changes, calcium accumulation by an external calcium electrode, and oxygen consumption with an oxyg...