The inhibitory activity of liver extracts on thymidine incorporation into DNA was markedly enhanced by manganese and zinc. Manganese-activated liver extract (Mn-liver extract) also inhibited incorporation of deoxycytidine and adenine into DNA. The Mn-liver extract had no effect on incorporation of thymidine-5'-triphosphate into DNA but blocked the phosphorylation of deoxythymidine. The phosphor...

The inhibitory activity of liver extracts on thymidine incorporation into DNA was markedly enhanced by manganese and zinc. Manganese-activated liver extract (Mn-liver extract) also inhibited incorporation of deoxycytidine and adenine into DNA. The Mn-liver extract had no effect on incorporation of thymidine-5'-triphosphate into DNA but blocked the phosphorylation of deoxythymidine. The phosphor...

The biological role of manganese (Mn(2+)) has been a long-standing puzzle, since at low concentrations it activates several polymerases whilst at higher concentrations it inhibits. Viral RNA polymerases possess a common architecture, reminiscent of a closed right hand. The RNA-dependent RNA polymerase (RdRp) of bacteriophage 6 is one of the best understood examples of this important class of po...

In the present study, micellar-enhanced ultrafiltration (MEUF) was used to remove manganese (Mn) (II) from synthetic wastewater. The effects of different operational conditions on the filtration performance of MEUF or the membrane were studied. It was found that the transmembrane pressure has a major influence on the permeate flux and an insignificant effect on the rejection coefficient. The pe...

Chemical distributions and microbial culture data are combined to identify the biogeochemical pathways that control the cycles of manganese and iron at the oxicanoxic transition of the Orca Basin. The redox transition coincides with an increase in salinity from 35 to 260‰; hence, mixing diagrams are used to constrain the salinity ranges over which consumption or production of solute species tak...

BACKGROUND Manganese-binding sites are found in several heme peroxidases, namely manganese peroxidase (MnP), chloroperoxidase, and the cationic isozyme of peanut peroxidase. The Mn-binding site in MnP is of particular interest. Oxidation of Mn(II) to Mn(III) is a key step in the biodegradation of lignin, a complex phenylpropanoid polymer, as well as many aromatic pollutants. Cytochrome c peroxi...

Although manganese (Mn) is an essential nutrient, toxicity has been demonstrated in workers accidentally exposed to large amounts. Chronic exposure to Mn can damage the nervous system and respiratory tract and result in symptoms similar to Parkinson disease. to Mn are more likely to develop Parkinson disease than the rest of the population, especially at an early age.5 Mn has been shown to inte...

Manganese is a contaminant in the wastewaters produced by Brazilian mining operations, and the removal of the metal is notoriously difficult because of the high stability of the Mn(II) ion in aqueous solutions. To explore a biological approach for removing excessive amounts of aqueous Mn(II), we investigated the potential of Mn(II) oxidation by both consortium and bacterial isolates from a Braz...

Two tetranuclear manganese(II) complexes {K(+)[Mn(4)(ThiaSO(2))(2)(OH)](-)} (1) and {K(+)[Mn(4)(ThiaSO(2))(2)(F)](-)} (2) have been synthesized under solvothermal conditions in methanol with p-tert-butylsulfonylcalix[4]arene (ThiaSO(2)). For both complexes, the structure has been established from single-crystal X-ray diffraction. The two complexes are best described as manganese squares sandwic...

PURPOSE The aims of this study were to investigate the effects of manganese (Mn) dust exposure on lung functions and evaluate the potential synergistic effect between smoking and Mn dust exposure among refinery workers. METHODS A retrospective study including 1658 workers in a ferromanganese refinery was conducted, with subjects who were from the Guangxi manganese-exposed workers healthy coho...