Selenium (Se) is a dietary essential trace element with important biological roles. Accumulating evidence indicates that Se compounds possess anticancer properties. Se is specifically incorporated into proteins in the form of selenocysteine and non-specifically incorporated as selenomethionine in place of methionine. The effects of Se compounds on cells are strictly compositional and concentrat...

The high-pressure behavior of amorphous selenium has been investigated with time-resolved diamond anvil cell synchrotron x-ray diffraction and computed microtomography techniques. A two-step dynamic crystallization process is observed in which the monoclinic phase crystallized from the amorphous selenium and gradually converted to the trigonal phase, thereby explaining previously observed anoma...

French Polynesians, like other remote maritime populations are intimately connected to the ocean which nourishes their daily life and culture. Their reliance on fish raises the issue of potential exposure to harmful natural and anthropogenic contaminants as well as providing essential nutrients. The purpose of this study was to assess the risks and benefits of fish consumption in French Polynes...

This study describes and compares two methods of atomic absorption spectrometry (AAS) for the selenium (Se) analysis in food: electrothermal AAS (ET AAS) and hydride generation method of AAS (HG AAS). The accuracy of the two methods was established by analysing two biological reference materials: Wheat Flour 1567a and Bovine Liver 1577b from the National Institute of Standards and Technology, U...

The use of photoconductors, especially amorphous selenium (a-Se), in x-ray imaging is currently of interest. A critical performance parameter of an imaging detector is the Swank factor for degradation of the signal to noise ratio, or DQE(0), due to variations in the detector response. The Swank factor is evaluated from measured pulse height spectra generated by the absorption of monoenergetic x...

A method to estimate the content of selenium in organics was introduced based on reversed phase-high performance liquid chromatography (RP-HPLC).The maximum absorption peak of piazselenol was at 330 nm and the optimized temperature and pH value were 40 degrees C and 2.8, respectively. The minimum detection concentration of selenium(IV) was 0.06 microg/mL and the measurable range was 0.12-12.0 m...

The use of excess conventional Phosphorus (P) fertilizers to improve agricultural productivity, in order to meet constantly increasing global food demand, potentially causes surface and ground water pollution, waterway eutrophication, soil fertility depletion, and accumulation of toxic elements such as high concentration of selenium (Se), arsenic (As) in the soil. Quite a number of soil microor...

Absorption of selenate and selenite by excised roots of Astragalus Crotalariae, a selenium accumulator, and of A. lentiginosus, a non-accumulator, was favored by CaCl(2) and a pH of 4.0. The uptake of selenate and possibly selenite, is metabolically linked. Roots of a number of Astragalus species were examined, and in all cases selenate entered the roots much faster than selenite. In these shor...

The conducting polymer poly(3,4-ethylenedioxythiophene), or PEDOT, is an attractive material for flexible electronics. We present combined molecular dynamics and quantum chemical calculations, based on density functional theory, of EDOT oligomers and isoelectronic selenium and tellurium derivatives (EDOS and EDOTe) to address the effect of temperature on the geometrical and electronic propertie...

Single-crystalline nanobelts and nanowires of trigonal selenium (t-Se) have been selectively synthesized in micellar solutions of nonionic surfactants. In particular, t-Se nanobelts about 30 nm in thickness were obtained in micellar solutions of poly(oxyethylene(20)) octadecyl ether (C18EO20), whereas t-Se nanowires were obtained in micellar solutions of poly(oxyethylene(10)) dodecyl ether (C12...