Amalgam has, ever since its introduction 150 years ago, been the subject of recurrent controversies because of its mercury content. Amalgam is an unstable alloy and continuously gives off mercury (Hg) in the form of gas, ions and abraded particles (Stock, 1939 a, Radics et al., 1970, Mocke, 1971, Till and Wagner, 1973, Svare et al., 1981). Amalgam contains an especially cor-rodible gamma-2-phas...

Thallium L III-edge x-ray absorption and iron-57 and tin-119 Mössbauer spectral measurements have been carried out to probe the electronic structure of the three sites in the filled skutterudite TlxCo42yFeySb12 and TlxCo4Sb122zSnz compounds with a range of x, y, and z values. The thallium L III-edge x-ray absorption spectra are independent of x, y, and z and are well reproduced by full multiple...

Extensive damage to organisms and declines in wildlife populations have been observed together with long-term bioaccumulation and biomagnification of persistent xenobiotic chemicals. Heavy metals, especially organic or biomethylated mercury, lead, cadmium and organic tin compounds have caused environmental damage through bioaccumulation on a local scale. Effects on wildife caused by bioaccumula...

The aggregating effects of adenosine diphosphate, thrombin, 5-hydroxytryptamine, tryptamine, adrenaline and noradrenaline, and tri-ethyl tin have been carefully compared. The first three compounds in some circumstances produce remarkably similar effects although there are important differences. The kinetics of aggregation induced by adrenaline (and noradrenaline) are quite different and the tri...

Leishmania amazonensis is the etiologic agent of the cutaneous and diffuse leishmaniasis often associated with drug resistance. Lapachol [2-hydroxy-3-(3'-methyl-2-butenyl)-1,4-naphthoquinone] displays a wide range of antimicrobial properties against many pathogens. In this study, using the classic microscopic in vitro model, we have analyzed the effects of a series of lapachol and chlorides com...

The article presents the results of the detection of low-concentration C1-C4 alcohols using a planar sensor, in which a sepiolite filter was applied next to the gas-sensitive layer based on tin dioxide. The sepiolite layer is composed of tubes that have a length of several microns, and the diameter of the single tube ranges from several to tens of nanometers. The sepiolite layer itself demonstr...

As concerns of the environmental impact of lead waste increase, the electronics industry is coming under increasing pressure to reduce or eliminate the use of lead in their manufacturing processes. Circuit assembly providers consequently must develop alternatives to eutectic tin-lead solder for use in their operations. Many ramifications are likely, including an initial decrease in process yiel...

A directed cross-aldol reaction of silyl enol ethers with carbonyl compounds, such as aldehydes and ketones, promoted by a Lewis acid, a reaction which is now widely known as the Mukaiyama aldol reaction. It was first reported in 1973, and this year marks the 40th anniversary. The directed cross-aldol reactions mediated by boron enolates and tin(II) enolates also emerged from the Mukaiyama labo...

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...