fe2+ ion-selective membrane sensor has been fabricated from polyvinyl chloride (pvc) matrixmembrane containing neutral carrier tetra phenyl porphyrin (tpp) ionophore. the addition ofsodium tetraphenylborate (natpb) and the plasticizer dbp has been found to substantiallyimprove the performance of the sensor. the best performance was obtained with the sensor havinga membrane of composition of tpp...

Membrane vesicles isolated from rabbit ventricular tissue rapidly accumulated Ca2+ when an outwardly directed Na+ gradient was formed across the vesicle membrane. Vesicles loaded internally with K+ showed only 10% of the Ca2+ uptake activity observed with Na+-loaded vesicles. Dissipation of the Na+ gradient with the monovalent cation exchange ionophores nigericin or narasin caused a rapid decli...

One of the main challenges for using microbial fuel cells (MFCs) is developing materials and architectures that are economical and generate high power densities. The performance of two cathodes constructed from two low-cost anion (AEM) and cation (CEM) exchange membranes was compared to that achieved using an ultrafiltration (UF) cathode, when the membranes were made electrically conductive usi...

Loss of ion homeostasis plays a central role in pathogenesis of ischemic cell damage. Ischemia-induced perturbation of ion homeostasis leads to intracellular accumulation of Ca2+ and Na+ and subsequent activation of proteases, phospholipases, and formation of oxygen and nitrogen free radicals. This signal transduction cascade results in long-term functional and structural changes in membrane an...

Reverse electrodialysis (RED) can harness the Gibbs free energy of mixing when fresh river water flows into the sea for sustainable power generation. In this study, we carry out a thermodynamic and energy efficiency analysis of RED power generation, and assess the membrane power density. First, we present a reversible thermodynamic model for RED and verify that the theoretical maximum extractab...

nitrate is an anion of major importance particularly in biological areas. excessive amounts in water supplies indicate pollution from sewage or agricultural effluents. the effects of excessive quantities of nitrate in water are well known. in this research structural modification of natural clinoptilolite by isomorphic substitution was performed. isomorphously substituted zeolite was prepared u...

With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF) alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN) cation exchange membrane. The effects of the swelling agent, sulfonation time and tempera...

A biomimetic aluminum oxide membrane having asymmetric channels with a minimum diameter of 20 nm, maximum 80 and length 5 µm was prepared using square pulse anodization. The effectively permitted transfer anions only showed an ionic current rectification characteristic ratio 2.4. After the sulfonic acid group introduced by surface modification, cations 2.7. This modulation direction consistent ...

background: in this study we have prepared the iga solution from normal human plasma using plasma fractionation and ion exchange chromatography. materials and methods: using fractionation of plasma with cold ethanol (starting with 8% ethanol), fraction iii was prepared as a suitable source for iga preparation. then it was treated with caprylic acid for separation of impurities. for enrichment o...