Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1) protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A) does not i...

Systemic wound response (SWR), a well-characterized systemic signaling response, plays crucial roles in plant defense responses. Progress in understanding of the SWR in abiotic stress has also been aided by the researchers. However, the function of SWR in freezing stress remains elusive. In this study, we showed that local mild mechanical wounding enhanced freezing tolerance in newly occurred s...

Hydrogen peroxide (H2O2), an oxidant generated by inflammatory cells, is an important mediator of injury of endothelial cells (ECs). Here we show that H2O2 induces up-regulation of the expression of Fas, a death signal, in human ECs in culture. Flow cytometric analysis with a mAb against human Fas showed that incubation for 24 h with H2O2 induced a dose-dependent increase in the level of Fas in...

Legionella pneumophila expresses two catalase-peroxidase enzymes that exhibit strong peroxidatic but weak catalatic activities, suggesting that other enzymes participate in decomposition of hydrogen peroxide (H2O2). Comparative genomics revealed that L. pneumophila and its close relative Coxiella burnetii each contain two peroxide-scavenging alkyl hydroperoxide reductase (AhpC) systems: AhpC1, ...

Site-directed mutants of cytochrome P-450cam (the cytochrome P-450 that acts as the terminal monooxygenase in the d-camphor monooxygenase system), in which threonine-252 had been changed to alanine, valine, or serine, were employed to study the role of the hydroxy amino acid in the monooxygenase reaction. The mutant enzymes were expressed in Escherichia coli and were purified by a conventional ...

Polyimide is of great technical importance because of its excellent material properties (including chemical inertness and radiation resistance) which are maintained even at low and at high temperatures. When thin polyimide foils are irradiated with energetic heavy ions, long nanometric tracks are formed. Under suitable conditions, the damaged material along these tracks is dissolved and develop...

In this research iron manganese oxide nanocomposites were prepared by co-precipitation, sol-gel and mechanochemical methods by using iron (III) nitrate, iron (II) sulfate and manganese (II) nitrate as starting materials. These nanocomposites were prepared in the presence of various catalyst beds. The polyvinyl pyrrolidon (PVP) was used as a capping agent to control the agglomeration of the nano...

Anionic DBS surfactant can be photodegraded in a TiO2 dispersion and H2O2 solution under an Hg-lamp (15 W) UV illumination or solar exposure. Degradation process has been monitored through cleavage of aromatic moiety. Degradation of the detergent was small when the photolysis was carried out in the absence of TiO2 and H2O2 an...

Introduction:studies have shown that the increase of active oxygen species is associated with damage to bone cells and the role of exercise and vitamin D on bone health has been proven;the aim of this study was to investigate the interactive effects of aerobic exercise with vitamin D supplements on bone resorption markers in rats exposed to oxidative damage induced by H2O2. <br...

in this paper, we use modified laplace decomposition method to solving initial value problems (ivp) of the second order ordinary differential equations. theproposed method can be applied to linear and nonlinearproblems