Manganese (Mn) oxides are environmentally abundant, highly reactive mineral phases that mediate the biogeochemical cycling of nutrients, contaminants, carbon, and numerous other elements. Despite the belief that microorganisms (specifically bacteria and fungi) are responsible for the majority of Mn oxide formation in the environment, the impact of microbial spe­ cies, physiology, and growth sta...

Nanostructures formed by chemical reaction can modify the interfacial forces present in aqueous solution near a surface. This study uses force-volume microscopyto explore this phenomenon for the growth of manganese oxide nanostructures on rhodochrosite. The interfacial forces above the oxide nanostructures are dominated by electrostatic repulsion for probe-surface separations greater than ca. 2...

The properties of nanomaterials and their potential applications have been given considerable attention by researchers in various fields, especially agricultural biotechnology. However, not much has been done to evaluate the role or effect of zinc oxide nanoparticles (ZnO-NPs) in regulating physiological and biochemical processes in response to saltinduced stress. For this purpose, some callus ...

Abstract Mineral surfaces are known for their ability to adsorb enzymes, but effects on enzyme activity not well studied. This study explores the extent which interaction with primary silicates and secondary minerals affects longevity of a model soil β‐glucosidase (BG). The BG was correlated capacity‐related properties (controlling space adsorption), including specific surface area (SSA) SSA‐no...

Objective:  To evaluate genotoxicity of zinc oxide, P. A. calcium hydroxide, mineral trioxide aggregate and an iodoform paste using comet assay on human lymphocytes.  Material Methods:  Two positive controls were used: methyl-methanesulfonate for the P.A. hydroxide aggregate; doxorubicin oxide. There also two negative controls: distilled water DMSO Comets identified fluorescence microscopy 100 ...

Amorphous hydrous manganese oxide (HMO) is an important mineral in soils and sediments influencing the mobility and bioavailability of metal contaminants. In this study, nickel and lead sorption to discrete HMO and HMO-coated montmorillonite was investigated mechanistically. The effect of pH and concentration revealed that when normalized to the mass of oxide present, the HMO-coated montmorillo...

Amorphous thin film oxygen evolving catalysts, OECs, of first-row transition metals show promise to serve as self-assembling photoanode materials in solar-driven, photoelectrochemical `artificial leaf' devices. This report demonstrates the ability to use high-energy X-ray scattering and atomic pair distribution function analysis, PDF, to resolve structure in amorphous metal oxide catalyst films...

OBJECTIVE The aim of this study was to compare the microbial leakage of mineral trioxide aggregate (MTA), Portland cement (PC), Sealapex and zinc oxide-eugenol (ZOE) as root-end filling materials. STUDY DESIGN An in vitro microbial leakage test (MLT) with a split chamber was used in this study. A mixture of facultative bacteria and one yeast (S. aureus+E. faecalis+P. aeruginosa+B. subtilis+C....

BACKGROUND This study examined the effects of addition of 10% and 25% by weight calcium hydroxide on the physicochemical properties of Portland cement associated with 20% bismuth oxide in order to develop a new pulp capping material. MATERIAL AND METHODS The solubility, pH value, setting time, compressive strength, and push out bond strength of modified Portland were evaluated and compared to...

Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B12. Complete oxidation of Mn(II) within 60 h required the additi...