a new method for the synthesis of water soluble polyaniline (pani) using hemin chloride (h.c) in the presence of hydrogen peroxide (h.p) is presented. hemin chloride is an effective catalyst for the oxidative polymerization of aniline in the presence of hydrogen peroxide at room temperature. the uv- vis absorption spectra of the product show a distinct absorption peak at 430 nm in ph 4.0 b...

The sea urchin egg is a quiescent cell...until fertilization, when the egg is activated. The classic respiratory burst at fertilization is the result of prodigious hydrogen peroxide production, but the mechanism for this synthesis is not known. Here we quantitate the kinetics of hydrogen peroxide synthesis at a single-cell level using an imaging photon detector, showing that 60 nM hydrogen pero...

scopes may cause chemical colitis [1–3]. However, it remains controversial whether the agent reponsible is the peracetic acid or the hydrogen peroxide in the solution. We recently encountered four cases of chemical colitis, showing characteristic morphologic and histologic features, including the “snow white sign”, following use of a new automated disinfection device in our endoscopy unit. The ...

OBJECTIVE This study evaluated the effects of carbamide peroxide and hydrogen peroxide on the biaxial flexural strength and flexural modulus of bovine dentin. MATERIALS AND METHODS Thirty coronal dentin disks (0.5 mm thick × 6.0 mm diameter) were prepared from bovine teeth. The disks were randomly divided into three groups (n=10): A control group (unbleached), a group bleached with 10% carbam...

Oxidation of cysteine residues of proteins is emerging as an important means of regulation of signal transduction, particularly of protein kinase function. Tools to detect and quantify cysteine oxidation of proteins have been a limiting factor in understanding the role of cysteine oxidation in signal transduction. As an example, the p38 MAP kinase is activated by several stress-related stimuli ...

Cardiac melanocyte-like cells (CMLCs) contribute to atrial arrhythmias when missing the melanin synthesis enzyme dopachrome tautomerase (Dct). While scavenging reactive oxygen species (ROS) in Dct-null mice partially suppressed atrial arrhythmias, it remains unclear if CMLCs influence atrial ROS and structure or if the electrical response of CMLCs to ROS differs from that of atrial myocytes. Th...

⎯Hydrogen, oxygen, and hydrogen peroxide have been measured downstream of an atmospheric pressure humid argon dielectric barrier discharge. The yield of the three species was studied as a function of the discharge power and gas flow rate. Hydrogen peroxide was measured after dissolution into water downstream of the discharge, while hydrogen and oxygen were measured in the gas phase. The product...

BACKGROUND The tooth whitening substances for extrinsic use that are available in Brazil contain hydrogen peroxide or carbamide peroxide. Several studies have attributed the appearance of lesions in the enamel morphology, including hypersensitivity, to these substances. Such lesions justify fluoride therapy and application of infrared lasers, among other procedures. However, there is no consens...

PURPOSE Iron plays a central role in the oxidative stress caused by hydrogen peroxide. The ubiquitous iron storage protein, ferritin, safely sequesters iron, reducing its ability to cause oxidative damage. Oxidative stress can activate mitogen-activated protein (MAP) kinase pathways with many downstream effects. The purpose of this study was to determine the effects of hydrogen peroxide on MAP ...

BspA is an abundant surface protein from Lactobacillus fermentum BR11, and is required for normal cystine uptake. In previous studies, a mutant strain deficient in BspA (L. fermentum PNG201) was found to be sensitive to oxidative stress. In this study, the biochemical basis for this was explored. It was found that under aerobic batch culture conditions in de Mann-Rogosa-Sharpe medium, both L. f...