Initial rates of biological (Shewanella putrefaciens strain CN32, pH 6.8) and chemical (ascorbate, pH 3.0) reduction of synthetic Fe(III) oxides with a broad range of crystallinity and specific surface area were examined to assess how variations in these properties are likely to influence the kinetics of bacterial Fe(III) oxide reduction in heterogeneous natural Fe(III) oxide assemblages. The r...

Abiotic reduction of 0.1 mM U(VI) by Fe(II) in the presence of synthetic iron oxides (biogenic magnetite, goethite, and hematite) and natural Fe(III) oxide-containing solids was investigated in pH 6.8 artificial groundwater containing 10 mM NaHCO3. In most experiments, more than 95% of added U(VI) was sorbed to solids. U(VI) was rapidly and extensively (> or = 80%) reduced in the presence of sy...

Despite the increasing rate of nanoparticles (NPS) production and their application in agriculture, few studies have focused on their effect on plant growth. So, the present research was conducted in laboratory and greenhouse conditions. First, superparamagnetic iron oxide nanoparticles (SPIONS) with a humic acid coating (Fe3O4/HA) were synthesized in laboratory...

BACKGROUND It has been proposed that the pH of airway lining fluid may regulate the fractional exhaled concentration of nitric oxide (Fe(NO)) in respiratory disease. METHODS Fe(NO), exhaled breath condensate (EBC) pH, and EBC concentrations of nitrite plus nitrate (NO2/NO3) were compared in 12 subjects with stable asthma, 18 with stable cystic fibrosis (CF), and 15 healthy control subjects. E...

The fate of phosphorus (P) during pedogenesis has been historically conceptualized (Walker-Syers model) with time as the primary controlling state factor. Herein, we demonstrate that both climate and lithology exert a strong interacting influence on P by examining coupled bioclimatic parent material effects soil fractions. Three transects were investigated spanning 2150-m elevation gradient (MA...

Oxidative stress has been implicated as an important factor in induction of many disorders such as nephropathy and cancer. Iron by producing hydroxyl radical can cause this kind of stress. On the other hand nitric oxide (NO) when its concentration is high results in oxidative stress. Iron and NO have some interactions in each other function but there is no total agreement on this. For example i...

The continental bio-cycling of silicon (Si) plays a key role in global Si cycle and as such partly controls global carbon (C) budget through nutrition of marine and terrestrial biota, accumulation of phytolith-occluded organic carbon (PhytOC) and weathering of silicate minerals. Despite the key role of elemental composition of phytoliths on their solubility in soils, the impact of plant cultiva...

BACKGROUND Iron (Fe) deficiency anemia remains the largest nutritional deficiency disorder worldwide. How the gut acquires iron from nano Fe(III), especially at the apical surface, is incompletely understood. OBJECTIVE We developed a novel Fe supplement consisting of nanoparticulate tartrate-modified Fe(III) poly oxo-hydroxide [here termed nano Fe(III)], which mimics the Fe oxide core of ferr...

The ferroelectric (FE) control of electronic transport is one of the emerging technologies in oxide heterostructures. Many previous studies in FE tunnel junctions (FTJs) exploited solely the differences in the electrostatic potential across the FTJs that are induced by changes in the FE polarization direction. Here, we show that in practice the junction current ratios between the two polarizati...