abstractin order to study the changes in chemical forms of zinc in the rhizosphere of two tuber plants and their relationship to plant uptake in a polluted soil, sequential (tessier et al., 1979) and single step extraction methods were used. in this research, three radish cultivars (raphanus sativus) and two turnip (brassica rapa) cultivars were planted in a complete randomized design pot exper...

A method is proposed to determine the fraction of the tautomeric forms of the imidazole ring of histidine in proteins as a function of pH, provided that the observed and chemical shifts and the protein structure, or the fraction of H(+) form, are known. This method is based on the use of quantum chemical methods to compute the (13)C NMR shieldings of all the imidazole ring carbons ((13)C(γ), , ...

Selenium compounds show much promise in the prevention of prostate and other human cancers. Various selenium chemical forms have been shown to differ widely in their anticancer properties. The main dietary form is selenomethionine, which we showed modulated p53 activity by causing redox regulation of key p53 cysteine residues. In the current study we included other selenium chemical forms, sodi...

The preparation of stable amorphous pemetrexed disodium of pharmaceutical purity as well as the process optimization for the preparation of the hemipentahydrate form of pemetrexed disodium are described. Analytical methods for the polymorphic and chemical purity studies of pemetrexed disodium and pemetrexed diacid forms were developed. The physicochemical properties of the amorphous and hydrate...

Background: The use of chemicals is essential in education resulting in exposure to these pollutant in a variety of chemical and research laboratories. Chemical contaminants in chemical laboratories are in different forms and chemical exposure risk assessment is important for choosing appropriate controls in protecting the health of operators, experts and students. For risk assessment in chemic...

It has been shown that the acetamido methyl protons of N-acetyl-D-glucosamine undergo a chemical shift to higher fields in their proton magnetic resonance spectrum when the inhibitor is bound to lysozyme. The observed chemical shift in the presence of the enzyme is different for the CP and /3-anomeric forms of Z-acetamido-Z-deoxy-D-glucopyranose indicating either a difference in the afhnity of ...

background: the use of chemicals is essential in education resulting in exposure to these pollutant in a variety of chemical and research laboratories. chemical contaminants in chemical laboratories are in different forms and chemical exposure risk assessment is important for choosing appropriate controls in protecting the health of operators, experts and students. for risk assessment in chemic...