-Well-characterized American Petroleum Institute clay standards, source clays from The Clay Minerals Society, and other secondary minerals were used to determine the effects of U concentration, temperature, and solution composition on U-sorption properties. Uranium concentrations ranged from about 1.00 x 10 -4 M to 4.00 x 10 7 M, temperatures from 5 ~ to 65~ and solution compositions containing...

To improve our understanding of uranium toxicity, the determinants of uranyl affinity in proteins must be better characterized. In this work, we analyzed the contribution of a phosphoryl group on uranium binding affinity in a protein binding site, using the site 1 EF-hand motif of calmodulin. The recombinant domain 1 of calmodulin from A. thaliana was engineered to impair metal binding at site ...

the main goal of this study is to investigate the capability of zeolites a and p synthesized from iranian natural clinoptilolite for uranium uptak. the removal of uranium(vi) from aqueous solution via ion exchange by zeolites in a single component system with various contact times,  temperatures and initial concentrations of uranium(vi) was investigated. the experimental results were fitted to ...

The family of cage clusters built by uranyl ions bridged through bidentate peroxide groups has been expanded by incorporation of 1-hydroxyethane-1,1-diphosphonic (etidronic) acid ligands. Six cage clusters containing from 16 to 64 uranyl ions, as well as from eight to 32 etidronic acid ligands have been synthesized and characterized. Incorporation of etidronic acid ligands introduces both new c...

The inclusion of NH(4)(+) as counterions in Car-Parrinello molecular dynamics (CPMD) simulations of anionic uranyl(VI) complexes is proposed as a viable approach to modeling "real" aqueous solutions. For [UO(2)F(4)(H(2)O)](2-) in water, it is shown that the inclusion of two NH(4)(+) ions strengthens the bond between uranyl and the water ligand by ca. 2 kcal/mol, improving the accordance with ex...

The uranyl ion (UO22+ ) binds phosphopeptides with high affinity, and when irradiated with UV-light, it can cleave the peptide backbone. In this study, high-accuracy tandem mass spectrometry and enzymatic assays were used to characterise the photocleavage products resulting from the uranyl photocleavage reaction of a tetraphosphorylated β-casein model peptide. We show that the primary photoclea...

introduction: recently depleted uranium is being widely used as anti-armour ammunition and at very high temperature, results in information of an aerosol of very small uranium oxide particles, which may be inhaled. it is alleged that these particles represent a new battlefield hazard because of the chemical toxicology and/or radioactivity. method & materials: male wistar strain albino rats were...

The structure of weeksite, K1.26Ba0.25Ca0.12[(UO2)2(Si5O13)]H2O, orthorhombic, a 14.209(2), b 14.248(2), c 35.869(4) Å, V 7262(2) Å3, space group Cmmb, has been solved by direct methods using data collected with MoK X-radiation and a CCDbased detector and refined by full-matrix least-squares techniques, on the basis of F2 for all unique reflections, to an agreement factor (R1) of 7.0% and a goo...

In numerous reports on selective solid-phase extraction (SPE) of uranium, the extraction of uranium is generally accepted as a direct coordination of the ligands on the solid matrix with the uranyl, in which the critical effect of the hydration shell on the uranyl is neglected. The related mechanism in the extraction process remains unclear. Herein, the detailed calculation of activation energy...

The structure of uranopilite, [(UO2)6(SO4)O2(OH)6(H2O)6](H2O)8, space group P1̄, a 8.896(2), b 14.029(3), c 14.339(3) Å, 96.610(4), 98.472(4), 99.802(4)°, V 1726.1(4) Å3, Z = 2, has been solved and refined on the basis of F2 for all unique data collected with monochromatic MoK X-radiation and a CCD-based detector to an agreement factor (R1) of 7.0%, calculated using 3907 unique observed reflecti...