In this study, we examined the effects of simultaneous adsorption of aqueous arsenate and uranyl onto aluminum oxide over a range of pH and concentration conditions. Arsenate was used as a chemical analog for phosphate, and offers advantages for characterization via X-ray absorption spectroscopy. By combining batch experiments, speciation calculations, X-ray absorption spectroscopy, and X-ray d...

The fine structure of young root hairs of radish was studied, with special attention to cytoplasm-wall relationships. Hairs up to 130 micro in length were examined after fixation of root tips in glutaraldehyde followed by osmium tetroxide. Microtubules occur axially aligned in the cytoplasm just beneath the plasmalemma, and extend from the base of the hair to within 2 to 3 micro of the tip. Pos...

The reduction of UVI uranyl halides or amides with simple LnII or UIII salts forms highly symmetric, linear, oxo-bridged trinuclear UV /LnIII /UV , LnIII /UIV /LnIII , and UIV /UIV /UIV complexes or linear LnIII /UV polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one- or two-electron uranyl reduction. The reactivity and magnetism of these ...

The complex chemistry of uranyl nitrate with mono and bi-functional neutral extractants shows, that it forms 1:2 and 1:1 complexes respectively. The structures of the isolated complexes show, that the water molecules from the primary coordination sphere of [UO2(NO3)2.2H2O] are replaced by the extractants completely and adopt a hexagonal bi-pyramidal geometry. However, the structural chemistry o...

Micrographs of mouse liver gap junctions, isolated with detergents, and negatively stained with uranyl acetate, have been recorded by low-irradiation methods. Our Fourier-averaged micrographs of the hexagonal junction lattice show skewed, hexameric connexons with less stain at the threefold axis than at the six indentations between the lobes of the connexon image. These substructural features, ...

The geomeffy, bond valences, and polymerization ofhexavalent uranium polyhedra from 105 well-refined structures are analyzed. The Utu cation is almost always present in crystal stnrctures as part of a nearly linear (UOr)z* uranyl ion that is coordinated by four, five or six equatorial anions in an approximately planar arangement perpendicular to the uranyl ion, giving square, pentagonal and hex...

Vitreous samples from bovine, ovine, human, canine, and lapine unfrozen eyes were found to contain fine fibrils which displayed no clearly discernible banding pattern when negatively stained with either phosphotungstic acid (pH 8.9) or silicotungstic acid (pH 7.0). The fibrils from the different species were found to be of similar width (10.5 to 12.5 nm) with the exception of the lapine samples...

The d. c. and a. c. polarography and cyclic voltammetry were applied to the study of uranyl-salicylate and uranyl-phthalate complexes. The study was limited to the pH range <5, because insoluble uranyl-hydroxydes are formed above this pH value. Uranyl-salicylate and -phthalate are irreversibly reduced. The electrode process is preceded by the chemical reaction of the complex with protons. By th...