Recent research has revealed that trace metals, particularly transition metals, play important roles in marine productivity. Most of the work has been on iron, which shows a nutrient-depleted profile in the upper ocean. Marine organisms have a variety of means for acquiring iron and other transition metal ions that differ from those of terrestrial organisms.

The modification of the electronic and chemical properties of Pt(111) surfaces by subsurface 3d transition metals was studied using density-functional theory. In each case investigated, the Pt surface d-band was broadened and lowered in energy by interactions with the subsurface 3d metals, resulting in weaker dissociative adsorption energies of hydrogen and oxygen on these surfaces. The magnitu...

Pseudomonas aeruginosa infection is problematic in patients with cystic fibrosis (CF). P. aeruginosa secretes a diversity of pigments, such as pyocyanin and pyoverdine. The aim of this study was to evaluate the effects of complexes of nickel(II) ([Ni(iaa)2(H2O)2]·H2O (iaa = imidazole-4-acetate anion), [Ni(1-allim)6](NO3)2 (1-allim = 1-allylimidazole) and NiCl2 on pyocyanin and pyoverdine produc...

The generation of active oxygen species by microsomes isolated from soybean seedlings was studied. NADPH-dependent superoxide anion production was 5.0 +/- 0.4 nmol . min(-1) mg(-1) of microsomal protein. Hydrogen peroxide generation by microsomes was 1.40 +/- 0.05 nmol . min(-1) mg(-1) of protein. Hydroxyl radical production, in the presence of ferric EDTA, evaluated through the generation of f...

more recently medical chemistry research has been focused on proteins that drive and controlcell cycle progression. among them, the cyclin dependent kinases (cdk’s) are a group ofserine/threonine kinases, which rule the transition between successive stages of the cell cycle. theactivity of cdk’s is regulated by multiple mechanisms, including binding to cyclins, which is a broadclass of positive...

Perchlorate (ClO4) may appear to be just another addition to a growing list of halogenated chemicals that persist in the environment, but the chemical characteristics of this inorganic anion make it quite unusual. Typical chlorinated aliphatic compounds, such as trichloroethylene (TCE), are relatively insoluble carbonaceous compounds, strictly used for industrial purposes. They are volatile, ad...

Anion-π interactions have been introduced recently to catalysis. The idea of stabilizing anionic intermediates and transition states on π-acidic surfaces is a new fundamental concept. By now, examples exist for asymmetric enolate, enamine, iminium and transamination chemistry, and the first anion-π enzyme has been created. Delocalized over large aromatic planes, anion-π interactions appear part...

Anion–p interactions have been introduced recently to catalysis. The idea of stabilizing anionic intermediates and transition states on p-acidic surfaces is a new fundamental concept. By now, examples exist for asymmetric enolate, enamine, iminium and transamination chemistry, and the first anion–p enzyme has been created. Delocalized over large aromatic planes, anion–p interactions appear part...