Under anaerobic conditions an exponentially growing culture of Escherichia coli K-12 was exposed to hydrogen peroxide in the presence of various compounds. Hydrogen peroxide (0.1 mM) together with 0.1 mM L-cysteine or L-cystine killed the organisms more rapidly than 10 mM hydrogen peroxide alone. The exposure of E. coli to hydrogen peroxide in the presence of L-cysteine inhibited some of the ca...

This study sought to evaluate the microhardness of enamel submitted to 10% carbamide peroxide treatment and different methods of remineralization involving sodium fluoride (NaF). Non-erupted third molars were used and 75 enamel blocks with standardized dimensions (4.0 x 4.0 x 2.0 mm) were obtained. Enamel blocks were randomly divided into five groups (n = 15): one control (no bleaching and no f...

*Corresponding Author: [email protected] Abstract In this work, a new method was developed for the catalytic reduction of hydrogen peroxide at glassy carbon electrode modified with silver nanoparticles and multi-wall carbon nanotubes. Silver incorporated in this modified electrode acted as catalyst to reduce hydrogen peroxide. First, the electrochemical behavior of silver, incorporated in m...

To directly examine the role of hydrogen peroxide in the killing of bacteria after ingestion by granulocytes, we have studied some of the events of phagocytosis of a mutant strain of pneumococci which is relatively deficient in peroxide production. The hydrogen peroxide-deficient pneumococci and the otherwise identical wild type were grown with [(14)C]arachidonic and [(3)H]palmitic acid labels ...

1. The velocity of decomposition of hydrogen peroxide by catalase as a function of (a) concentration of catalase, (b) concentration of hydrogen peroxide, (c) hydrogen ion concentration, (d) temperature has been studied in an attempt to correlate these variables as far as possible. It is concluded that the reaction involves primarily adsorption of hydrogen peroxide at the catalase surface. 2. Th...

BACKGROUND The authors tested the adjunctive use of light with a 15 percent peroxide gel as a single-visit, in-office tooth whitening system. METHODS Subject (N = 87) with stained (> shade D4, Vita Zahnfabrik, Bad Säckingen, Germany) anterior teeth were randomly assigned to test (peroxide and light), peroxide control (peroxide gel) or light control (placebo gel and light) groups and were trea...

IN previous communications the electrode potential behaviour of haemolytic streptococci [Hewitt, 1930, 1], C. diphtheriae [1930, 2], staphylococci [1930, 3] and pneumococci [1930, 4] has been described by the author and it has been shown that the oxidation-reduction potentials established in bacterial cultures depend upon the cultural conditions and upon the organism studied. The potentials dev...

The overproduction of hydrogen peroxide is implicated in the progress of numerous life-threatening diseases and there is a great need for the development of contrast agents that can detect hydrogen peroxide in vivo. In this communication, we present a new contrast agent for hydrogen peroxide, termed peroxalate micelles, which detect hydrogen peroxide through chemiluminescence, and have the phys...