The secondary structures of poly(dG-dC).poly(dG-dC) in the presence of alcaline , alcaline earth and first row transition metal ions (Na+, Mg2+, Co2+, Ni2+) are investigated by infrared spectroscopy. The conformational transitions are studied as a function of the hydration of the polynucleotide and counter-ion nature and content. The use of selectively deuterated poly(dG-dC).poly(dG-dC) on the ...

Lu3+/Yb3+ and Lu3+/Er3+ co-doped Sb2Se3 nanomaterials were synthesized by co-reduction method in hydrothermal condition. Powder X-ray diffraction patterns indicate that the LnxLn'xSb2-2xSe3 Ln: Lu3+/Yb3+ and Lu3+/Er3+ crystals (x = 0.00 - 0.04) are isostructural with Sb2Se3. The cell parameters were increased for compounds upon increasing the dopant content (x). Scanning electron microscopy and...

Alkaline phosphatase of Escherichia coli (a dimeric zinc metalloenzyme of identical subunits) containing either 2 catalytic Zn(II) ions or 2 catalytic Cd(I1) ions shows absolute negative cooperativity of phosphate binding as determined by 31P NMR of enzyme-bound phosphate species. With excess phosphate at millimolar concentrations, only 1 mol of noncovalent phosphate complex, E.P (31P resonance...

Photon induced decay of C5(-) has been measured in an electrostatic storage ring. The time dependence of the photo-enhanced decay is close to a 1∕t decay which indicates a thermal process. The deviation from the expected power of -1 is quantitatively explained by the small heat capacity of the anion. Measurements of the photo-enhanced decay at different storage times and photon energies allow a...

Toxicity and accumulation of Cd2+ in yeasts were studied in eight different yeast species. The adaptation to toxic concentration of this metal was dependent on the production of extracellular yeast glycoproteins. The highest concentration of Cd2+ ions in the growth medium was tolerated by a Hansenula anomala, strain while the lowest tolerance was found by the strain of species Saccharomyces cer...

The catalytic properties of modified Au/TiO₂ catalysts for low-temperature CO oxidation are affected by deactivation and reactivation after long-term storage and by redox treatments. The effect of these phenomena on the catalysts was studied by HRTEM, BET, SEM, FTIR CO, XPS and H₂ TPR methods. The main cause for the deactivation and reactivation of catalytic properties is the variation in the e...