OBJECTIVE This study aimed to compare the effects 0.5% and 1% sodium, amine and stannous fluoride at different pH on enamel erosion in vitro. METHODS Bovine enamel samples were submitted to a cyclic de- and remineralisation for 3 days. Each day, the samples were exposed for 120 min to pooled human saliva and subsequently treated with one of the fluoride solutions for 3 min: amine fluoride (Am...

Hydrogen (H(+)) and hydroxide (OH(-)) ions in aqueous solution have anomalously large diffusion coefficients, and the mobility of the H(+) ion is nearly twice that of the OH(-) ion. We describe molecular dynamics simulations of a dissociating model for liquid water based on scaling the interatomic potential for water developed by Ojamäe-Shavitt-Singer from ab initio studies at the MP2 level. We...

In gamma irradiated aqueous acidic uranium solutions, tetravalent uranium ions are easily oxidized while U(VI) ions remain unchanged. In general, valence change of polyvalent metallic ions during chemical reprocessing of spent nuclear fuel solutions can lead to undesirable effects under the influence of the existing gamma radiations. Consequently, studies on valence stabilization of Uranium ion...

OBJECTIVES Differences in peritoneal fluid handling in the acute setting can be expected if children are converted to pH-neutral dialysis solutions because conventional acidic solutions exert toxic effects on peritoneal mesothelial cells and microcirculation. Peritoneal fluid kinetics was therefore investigated with both types of solutions in a group of children. DESIGN Peritoneal equilibrati...

The splitting of water into hydrogen and oxygen molecules using sunlight is an attractive method for solar energy storage. Until now, photoelectrochemical hydrogen evolution is mostly studied in acidic solutions, in which the hydrogen evolution is more facile than in alkaline solutions. Herein, we report photoelectrochemical hydrogen production in alkaline solutions, which are more favorable th...

Myxicola giant axons were studied using standard voltage-clamp techniques in solutions whose pH values ranged from 3.9 to 10.2. Buffer concentrations of 50 mM or greater were necessary to demonstrate the full effect of pH. In acidic solutions the axon underwent a variable depolarization, and both the sodium and potassium conductances were reversibly depressed with approximate pKa's of 4.8 and 4...

Long-term urinary catheterisation is rarely completely free of complications. Catheter blockage from mineral salt encrustation occurs in 40-50 per cent of patients. Recurrent blockage is distressing to patients and carers and costly to health services in both time and resources. Laboratory-based evidence shows acidic maintenance solutions can be effective in dissolving encrustations. This is su...

The objective of this study was to compare corrosion behavior in several titanium alloys with immersion in acidulated saline solutions containing hydrogen peroxide. Seven types of titanium alloy were immersed in saline solutions with varying levels of pH and hydrogen peroxide content, and resulting differences in color and release of metallic elements determined in each alloy. Some alloys were ...