Contamination of freshwater resources, fresh produce and some processed foods by perchlorate (ClO4 -) is a growing problem in the United States. The anion perchlorate is a naturally occurring as well as an anthropogenic chemical which occurs as salts of ammonium, sodium and potassium. The natural sources of perchlorate include Chilean caliche which is mined for use as a natural source of NaNO3 ...

The objective of the present work was to compare the effects of groups of tin and lead organometallic compounds and their mixtures with amphiphilic quaternary ammonium salts (QAS) on the process of calcium ion desorption from lecithin liposome membranes, as dependent on the properties of the hydrophilic and hydrophobic parts of QAS. In the investigations the method of radioactive labels was app...

THE final phase of amino-acid metabolism, involving the removal of nitrogen from the amino-group and the production of urea, is generally regarded as involving two distinct processes: (1) deamination, with the liberation of ammonia, (2) dehydration of ammonium carbonate, with formation of urea. The change being represented as: R. CH(NH2) . COOH NH3 (NH4C03CON2H4 Now, while there is no doubt as ...

The synthesis and characterization of a series of hybrid organic-inorganic [2]rotaxanes is described. The ring components are heterometallic octa- ([Cr(7)MF(8)(O(2)C(t)Bu)(16)]; M = Co, Ni, Fe, Mn, Cu, Zn, and Cd) nuclear cages in which the metal centers are bridged by fluoride and pivalate ((t)BuCO(2)(-)) anions; the thread components feature dialkylammonium units that template the formation o...

Using the spin label method (ESR) it has been shown that biologically active, amphiphilic compounds (quaternary ammonium salts (AS) containing polar heads with single and double positive charge caused, at low concentrations, decrease fluidity of liposome membranes formed with egg yolk lecithin (EYL). At higher concentrations an increase in fluidity was observed. With compounds having a single p...

[reaction: see text] The catalytic enantioselective electrophilic fluorination promoted by quaternary ammonium salt from cinchonine as a phase-transfer catalyst is described. Treatment of beta-keto esters with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding alpha-fluoro beta-keto esters in exellent yields with good to moderate enantiom...

IN a previous paper [Clifford, 1925] the effects of the halogen salts of sodium, potassium, ammonium, and calcium on salivary digestion were described. These salts were found to vary in their action on ptyalin, some delaying digestion, others being inert, and some increasing the speed of reaching the achromic point. It was thought advisable to continue the investigation with other enzymes, and ...

Distinct concentration ranges of selected quaternary ammonium and phosphonium salts were elaborated to induce stimulatory or inhibitory effects, respectively, on photosynthetic reactions. By means of fluorescence induction measurements 3 different effects of alkylbenzyldimethylammonium chloride (ABDAC; zephirol) in chloroplast preparations from Pisum sativum were observed. 60 microM ABDAC produ...

The recognition of the importance of the true reaction or hydrogen ion concentration of the blood and body fluids of organisms, as opposed to their titratable acidity, has been responsible in recent years for many important advances in physiology and for a large and rapidly growing body of literature. So great has been the interest in the determination, made possible by the development of the i...

Since the classical work of Crum Brown and Fraser, the curariform action of many onium salts has been recognized, and other activities exerted by these compounds have been described, such as those commonly called nicotine-like or muscarine-like. In the present paper an account is given of the actions of members of a polymethylene bistrimethylammonium series, whose general formula is (CH,), N+(C...