introduction: the present study evaluated the element distribution in completely set calcium-enriched mixture (cem) cement after application of 35% carbamide peroxide, 40% hydrogen peroxide and sodium perborate as commercial bleaching agents using an energy-dispersive x-ray microanalysis (edx) system. the surface structure was also observed using the scanning electron microscope (sem). methods ...

The hydrogen peroxide dissociation on MgO(001) films deposited on Mo(001) surface is investigated by employing periodic density-functional theory methods. The pristine MgO(001) surface showing chemical inertness prefers the weak adsorbing molecular configuration and is extremely difficult to react with hydrogen peroxide. As far as we know, energetically favorable decomposition state of hydrogen...

We constructed and characterized a Xanthomonas campestris pv. phaseoli oxyR mutant. The mutant was hypersensitive to H2O2 and menadione killing and had reduced aerobic plating efficiency. The oxidants' induction of the catalase and ahpC genes was also abolished in the mutant. Analysis of the adaptive responses showed that hydrogen peroxide-induced protection against hydrogen peroxide was lost, ...

Hydrogen peroxide sensing microelectrodes for scanning electrochemical microscopy (SECM) have been developed and used to measure hydrogen peroxide in the diffusion layer during electrochemical reduction of oxygen on gold and carbon electrodes. These microelectrode biosensors were also used to detect immobilized glucose oxidase through the production of hydrogen peroxide during enzymatic oxidati...

A new mechanism for alkane functionalization by iron(III)-peroxide adducts was pro­ posed, and the importance of electrophilic nature of the metal-peroxide adduct with t] 1coordination mode was emphasized. This idea suggests that formation of high-valent ironoxo species occurs most likely when the metal-peroxide intermediate is activated through electronic interaction with both the peripheral o...

This in vivo study determined the kinetics of 3% hydrogen peroxide in a bleaching gel within the first hour. The material used in this study was 3% hydrogen peroxide gel (Perfecta 3/15, Premier Dental Products Co) and the study involved 10 subjects who met the inclusion and exclusion criteria. Each subject wore the tray with gel six different times on separate days. Evaluation of the remaining ...

Hydrogen peroxide induces oxidation and consequently inactivation of many protein tyrosine phosphatases. It was found that hydrogen peroxide, in the presence of carboxylic acids, was efficiently activated to form even more potent oxidant - peroxy acid. We have found that peroxytetradecanoic acid decreases the enzymatic activity of CD45 phosphatase significantly more than hydrogen peroxide. Our ...

The use of hydrogen peroxide as a precursor to improvised explosives has made its detection a topic of critical importance. Chemiresistor arrays comprised of 50 nm thick films of metallophthalocyanines (MPcs) are redox selective vapor sensors of hydrogen peroxide. Hydrogen peroxide is shown to decrease currents in cobalt phthalocyanine sensors while it increases currents in nickel, copper, and ...

Prions pose a challenge to decontamination, particularly before the re-use of surgical instruments. They have relatively high resistance to standard decontamination methods and require extreme chemical and/or heat-based treatments for devices used in known or suspected cases of disease. This study investigated the effectiveness of a new gaseous hydrogen peroxide sterilisation process for prions...