Recently, a variety of physiologically based pharmacokinetic (PBPK) models have been developed for the essential element manganese. This paper reviews the development of PBPK models (e.g., adult, pregnant, lactating, and neonatal rats, nonhuman primates, and adult, pregnant, lactating, and neonatal humans) and relevant risk assessment applications. Each PBPK model incorporates critical features...

We studied the effect of manganese and various organic chelators on the distribution, depolymerization, and mineralization of synthetic 14C-labeled lignins (DHP) in cultures of Phanerochaete chrysosporium. In the presence of high levels of manganese [Mn(II) or Mn(III)], along with a suitable chelator, lignin peroxidase (LiP) production was repressed and manganese peroxidase (MnP) production was...

This research aimed to determine if less invasive biological specimens (other than blood), such as feces and clipped toenails could be used to determine manganese concentrations among occupationally exposed human subjects. In addition to blood samples, which have routinely been used in determining manganese concentration, specimens were collected from welders working at the Electricity Generati...

In the present study, a successful attempt has been made to develop a simple method for the simultaneous determination of manganese (II) and iron (III) in an industrial effluent using differential pulse polarography (DPP) technique. Quantification of manganese (II) and iron (III) was done in Triethanolamine and KOH as a supporting electrolyte. The polarogram recorded for the industrial effluent...

Oxalate decarboxylase (OxdC) from Bacillus subtilis is a hexamer containing two manganese ions per 43.6 kDa subunit. A single highly redundant data set collected at a medium resolution of 2 A on an in-house X-ray source was sufficient to solve the structure by the single-wavelength anomalous diffraction (SAD) method using the anomalous signal from the manganese ions. The experimentally phased e...

Two experimental high strength steel weld metals were produced with 7 wt. % nickel and manganese at 2 or 0.5 wt. %. Neural network predictions that Mn reductions increase toughness were confirmed with impact energy increasing from 32 to 113 J at –40 °C. High resolution microstructural investigations showed that both weld metals contained mainly martensite at interdendritic regions and predomina...

Previous measurements show that calcium manganese oxide nanoparticles are better water oxidation catalysts than binary manganese oxides (Mn3O4, Mn2O3, and MnO2). The probable reasons for such enhancement involve a combination of factors: The calcium manganese oxide materials have a layered structure with considerable thermodynamic stability and a high surface area, their low surface energy sugg...

Iron and manganese are relevant constituents of the earth's crust and both show increasing mobility when reduced by free electrons. This reduction is known to be controlled by microbial dissimilation processes. Alternative sources of free electrons in nature are cloud-to-ground lightning events with thermal and galvanic effects. Where thermal effects of lightning events are well described, less...

Soluble manganese in the intermediate +III oxidation state (Mn3+ ) is a newly identified oxidant in anoxic environments, whereas acetate is a naturally abundant substrate that fuels microbial activity. Microbial populations coupling anaerobic acetate oxidation to Mn3+ reduction, however, have yet to be identified. We isolated a Shewanella strain capable of oxidizing acetate anaerobically with M...

Manganese is a naturally occurring element and an essential nutrient. Comprising approximately 0.1% of the earth’s crust, it is the twelfth most abundant element and the fifth most abundant metal. Manganese does not exist in nature as an elemental form, but is found mainly as oxides, carbonates, and silicates in over 100 minerals with pyrolusite (manganese dioxide) as the most common naturally-...