Escherichia coli has a specitic active transport system for magnesium which can be studied with the radioisotope 28Mg. The accumulation of 2*Mg is temperature-dependent and inhibited by cyanide, dinitrophenol, and m-chlorophenyl carbonylcyanide hydrazone. The initial rate of uptake of SMg shows typical saturation kinetics with a & = 18 /LM magnesium and a V,,,,, = 0.56 pmole per min per 1012 ce...

Metal silicide nanowires (NWs) are very interesting materials with diverse physical properties. Among the silicides, manganese silicide nanostructures have attracted wide attention due to their several potential applications, including in microelectronics, optoelectronics, spintronics and thermoelectric devices. In this work, we exhibited the formation of pure manganese silicide and manganese s...

Manganese oxides are often highly reactive and easily reduced, both abiotically, by a variety of inorganic chemical species, and biologically during anaerobic respiration by microbes. To evaluate the reaction mechanisms of these different reduction routes and their potential lasting products, we measured the sequence progression of microbial manganese(IV) oxide reduction mediated by chemical sp...

Two types of manganese oxides have been prepared by hydrolysis of tetranuclear Mn(iii) complexes in the presence or absence of phosphate ions. The oxides have been characterized structurally using X-ray absorption spectroscopy and functionally by O2 evolution measurements. The structures of the oxides prepared in the absence of phosphate are dominated by di-μ-oxo bridged manganese ions that for...

Exposure to an excess amount of manganese causes neurological symptoms similar to Parkinson's disease. Zinc transporters such as Zrt, Irt-related protein 8 (ZIP8), and ZIP14 have been shown to have affinities for Mn(2+) as well as Zn(2+), but their roles in Mn(2+) uptake in neuronal cells remain unclear. Recent studies have shown that another zinc transporter ZnT10 may be involved in manganese ...

The 33 kDa manganese-stabilizing extrinsic protein binds to the lumenal side of photosystem II (PS II) close to the Mn(4)Ca cluster of the oxygen-evolving complex, where it limits access of small molecules to the metal site. Our previous finding that the removal of this protein did not alter the magnetic coupling regime within the manganese cluster, measured by electron spin-echo envelope modul...

Manganese is an essential metal that participates as a co-factor in a number of critical biological functions such as electron transport, detoxification of free radicals, and synthesis of neurotransmitters. Like other heavy metals, high concentrations of manganese are toxic. For example, chronic overexposure to manganese leads to movement disorders. In order to maintain this balance between bei...

background dietary factors such as intake of minerals may play a role in the etiology of esophageal cancer. although it has been hypothesized that manganese can affect the risk of some types ofcancer, its role in esophageal cancer is unknown. the objective of this study was to investigate the association between intakes of manganese with esophageal cancer in golestan cohort study. materials and...

Manganese stains, crusts, and nodules are widely distributed on the insular slopes of the Hawaiian ridge. The thickness of the manganese crusts depends on depth of water, water circulation, and the age and lithology of the substrate, and varies from absent to stains off the island of Hawaii to a maximum of 5 cm in the vicinity of Midway. Scanning electron microscope studies indicate that the in...

In natural photosynthesis, the oxygen evolving center is a tetranuclear manganese cluster stabilized by amino acids, water molecules and counter ions. However, manganese complexes are rarely exhibiting catalytic activity in water oxidation conditions. This is also true for the family of water oxidation catalysts (WOCs) obtained from POM chemistry. We have studied the activity of the tetranuclea...