We propose a mechanism for oligonucleotide (ODN) release from cationic lipid complexes in cells that accounts for various observations on cationic lipid-nucleic acid-cell interactions. Fluorescent confocal microscopy of cells treated with rhodamine-labeled cationic liposome/ fluorescein-labeled ODN (F-ODN) complexes show the F-ODN separates from the lipid after internalization and enters the nu...

In the alpha7 nicotinic acetylcholine receptors, we analyze the contribution of mutations E237A and V251T, together with the proline insertion P236', in the conversion of the charge selectivity from cationic to anionic. We show that the triple mutant exhibits spontaneous openings displaying anionic selectivity. Furthermore, at position 251, hydrophilic or even negatively charged residues are co...

Bama is one of the major concentrating plant in Iran which treats nearly 1500 tons per day sulphidic lead and zinc ore. Large amount of oxidized ore exist in Bama which has been extracted along with sulphidic ore. The main objective of the present investigation was the up-grading of the ore from Goshfil which is the major deposit in Bama. The ore contained about 16% zinc as smithsonite, about 1...

While azolate anions have been extensively used as anionic linkers in framework design, we now demonstrate the synthesis of square-grid networks that utilise their cationic analogues, imidazolium ions, as linkers. The resulting imidazolium frameworks are direct hydrogen-bonded analogues of square-grid metal azolates and the first examples of an inverted polarity framework design based on anioni...

A study of the effects of synthetic detergents and wetting agents on respiration and glycolysis of Gram-positive and Gram-negative microorganisms has led to the following conclusions. 1. All the cationic detergents studied are very effective inhibitors of bacterial metabolism at 1:3000 concentration, and several are equally active at 1:30,000. Few of the anionic detergents inhibit as effectivel...

Human secretory group IIa phospholipase A2 (hIIa-PLA2) contains a large number of prominent cationic patches on its molecular surface and has exceptionally high affinity for anionic surfaces, including anionic membranes. To identify the cationic amino acid residues that support binding of hIIa-PLA2 to anionic membranes, we have performed extensive site-directed mutagenesis of this protein and m...

Objective of this study was to determine the effects of varying dietary cation-anion differences (DCAD) in prepartum period on milk fever, subclinical hypocalcemia and negative energy balance in dairy cows of Urmia, Iran. Ninety nine Holstein cows assigned to three groups (n=33) were fed diets with DCAD of -24 (anionic), +80 (cationic) and +230 (cationic) mEq/Kg dry matter for 3 weeks before ex...

Nisin is a cationic polycyclic bacteriocin secreted by some lactic acid bacteria. Nisin has previously been shown to permeabilize liposomes. The interaction of nisin was analyzed with liposomes prepared of the zwitterionic phosphatidylcholine (PC) and the anionic phosphatidylglycerol (PG). Nisin induces the release of 6-carboxyfluorescein and other small anionic fluorescent dyes from PC liposom...

We evaluated the mechanism of uptake of carboxyfluorescein-containing small unilamellar liposomes of different surface charge by trophoblast cells in culture. Carboxyfluorescein-encapsulated neutral liposomes were prepared by using equimolar concentrations of lecithin and cholesterol. Anionic and cationic liposomes were prepared by adding dicetylphosphate and stearylamine. Trophoblast cells fro...

Two biodegradable quaternary ammonium salts were synthesized and used as cationic collectors in processing iron ores by froth flotation. The flotation behaviors of iron minerals with the new biodegradable quaternary ammonium collectors were investigated by micro-flotation tests of quartz (SiO2) and magnetite (Fe3O4). It was observed that the new biodegradable collectors were effective in separa...