A sulfur:ferric ion oxidoreductase that utilizes ferric ion (Fe3+) as an electron acceptor of elemental sulfur was purified from iron-grown Thiobacillus ferrooxidans to an electrophoretically homogeneous state. Under anaerobic conditions in the presence of Fe3+, the enzyme reduced 4 mol of Fe3+ with 1 mol of elemental sulfur to give 4 mol of Fe2+ and 1 mol of sulfite, indicating that it corresp...

To establish the structure of ferric ions in strongly alkaline (pH > 13) environments, aqueous NaOH solutions supersaturated with respect to Fe(III) and the solid ferric-hydroxo complex salts precipitating from them have been characterized with a variety of experimental techniques. From UV measurements, in solutions of pH > 13, only one kind of Fe(III)-hydroxo complex species was found to be pr...

The chemical degradation of dieldrin in ferric sulfide and iron powder aqueous suspension was investigated in laboratory batch type experiments. To identify the reaction mechanism, reduced copper was used as reductant. More than 90% of dieldrin was degraded using both reaction systems after 29 days. Initial degradation rate of the pesticide using ferric sulfide was superior to that using iron p...

Bonding between laboratory light-cured composite and surface treated Au-Ag-Pd alloy was investigated using newly developed 4-META/MMA-TBB opaque resin. Shear bond strength after 20,000 thermocycles obtained from heated alloy with this method was 25.1 MPa. Ion-coated specimen showed 25.6 MPa after 50,000 thermocycles with decrease in bond strength being small. Ferric chloride treated specimen, h...

Lipoxygenases are non-heme iron dioxygenases that catalyze the oxygenation of polyunsaturated fatty acids. Using soybean lipoxygenase-1 as a model, we have shown that two classes of lipoxygenase inhibitors currently in development as potential antiinflammatory agents obtain a significant amount of their potency by reducing the lipoxygenase active-site iron from the active ferric state to the in...

Added substrates, acetone and t-butyl alcohol, strongly retard the decomposition of H(2)O(2) brought about by ferric ethylenediaminetetraacetate (EDTA) at pH 8-9.5. Their relative effectiveness and the kinetic form of the retardation are consistent with their interruption of a hydroxyl radical chain that is propagated by HO. attack both upon H(2)O(2) and on complexed and uncomplexed EDTA. Simil...

Ferric hydroxide supported Au prepared with co-precipitation without heat treatment could be a very effective catalyst for selective CO oxidation in the presence of H2 at lower temperatures.