The formation of a bond between a bacterium and a mineral is ultimately controlled by forces that operate over length scales of a few nanometers. This manuscript presents evidence that bacteria may actively modulate forces at the cell-mineral interface to promote contact with specific mineral phases. Nanoto pico-Newton forces were measured between goethite (FeOOH) and each of two species of Gra...

Shewanella putrefaciens, a gram-negative, facultative anaerobe, is active in the cycling of iron through its interaction with Fe (hydr)oxides in natural environments. Fine-grained Fe precipitates that are attached to the outer membranes of many gram-negative bacteria have most often been attributed to precipitation and growth of the mineral at the cell surface. Our study of the sorption of nonb...

Surface-enhanced Raman spectroscopy (SERS) of species bound to environmentally relevant oxide nanoparticles is largely limited to organic molecules structurally related to catechol that facilitate a chemical enhancement of the Raman signal. Here, we report that magnetite (Fe3O4) nanoparticles provide a SERS signal from oxalic acid and cysteine via an electric field enhancement. Magnetite thus l...

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types processing carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C 72 h), and other prescinding first step. Nanosheet-assembled flowers nanoparticle agglomerates obtained from procedur...

introduction: this case report describes apexogenesis treatment of three molar teeth of an 8-year-old boy using three different pulpotomy agents. methods: pulpotomy was performed on decayed immature molar teeth with established irreversible pulpitis and the remaining pulp was capped with either zinc oxide eugenol, proroot mineral trioxide aggregate or calcium-enriched mixture (cem) cement. teet...

Abstraet--A new iron oxide dissolution method designed to measure the abundance of "free" Fe oxide phases and associated elements in soils and sediments has been tested. The method employs a ternary complex of Ti(III), citrate, and ethylenediaminetetraacetate (EDTA) as a reductant and bicarbonate as a proton acceptor. The Ti(III)-citrate-EDTA-HCO3 method dissolved more synthetic amorphous ferri...