Synthesize Phosphomolybdic Acid-Doped Polyaniline Microspheres for Catalytic Applications

2014 ◽  
Vol 484-485 ◽  
pp. 137-140
Author(s):  
Jin Zhang Tao
Keyword(s):  
Hydrogen Peroxide ◽  
Formation Mechanism ◽  
Critical Role ◽  
Phosphomolybdic Acid ◽  
Major Effect ◽  
High Conversion ◽  
Composite Microspheres ◽  
Pani Composite ◽  
Doped Polyaniline ◽  
Catalytic Applications

Polyaniline (PANI) composite have generated great interest in the catalyst field due to the coordinate properties of their component. Herein, PANI-PMo12 composite microspheres were successfully fabricated via a facial oxypolymerization with hydrogen peroxide as oxidant and phosphomolybdic acid (PMo12) as dopant. The PANI-PMo12 microspheres were characterized by SEM, XRD, FTIR and XPS. The concentration of PMo12 had a major effect on the diameter of microsphere. The solvent ethanol also played a critical role in the formation of microspheres. The formation mechanism of the PANI-PMo12 microspheres was proposed. Further, the composite microspheres could be directly used as catalyst and displayed a high conversion and selectivity in the epoxidation of cis-cyclooctene with aqueous H2O2 as an oxidant.

Synthesis of phosphomolybdic acid/nanocrystalline titanium silicalite-1 catalyst in the presence of hydrogen peroxide for effective adsorption-oxidative desulfurization

2022 ◽  
Author(s):  
Siyue Wang ◽  
Tong Huan ◽  
Haonan Li ◽  
Xin Shi ◽  
Di Liu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Desulfurization ◽  
Phosphomolybdic Acid ◽  
Impregnation Method ◽  
Titanium Silicalite ◽  
Nanocrystalline Titanium

The phosphomolybdic acid (HPMo) supported on microporous nanocrystalline titanium silicalite-1 zeolite (Nano-TS-1) catalysts were prepared in the absence or presence of hydrogen peroxide via the impregnation method. The catalysts were...

Gentamicin enhanced production of hydrogen peroxide by renal cortical mitochondria

1987 ◽  
Vol 253 (4) ◽  
pp. C495-C499 ◽  
Author(s):  
P. D. Walker ◽  
S. V. Shah
Keyword(s):  
Hydrogen Peroxide ◽  
Mitochondrial Respiration ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Reactive Oxygen Metabolites ◽  
Enhanced Production ◽  
Production Of Hydrogen ◽  
Hydrogen Peroxide Generation ◽  
Dose Dependent ◽  
Oxygen Metabolites

Agents that affect mitochondrial respiration have been shown to enhance the generation of reactive oxygen metabolites. On the basis of the well-demonstrated ability of gentamicin to alter mitochondrial respiration (stimulation of state 4 and inhibition of state 3), it was postulated that gentamicin may enhance the generation of reactive oxygen metabolites by renal cortical mitochondria. The aim of this study was to examine the effect of gentamicin on the production of hydrogen peroxide (measured as the decrease in scopoletin fluorescence) in rat renal cortical mitochondria. The hydrogen peroxide generation by mitochondria was enhanced from 0.17 +/- 0.02 nmol . mg-1 . min-1 (n = 14) in the absence of gentamicin to 6.21 +/- 0.67 nmol . mg-1 . min-1 (n = 14) in the presence of 4 mM gentamicin. This response was dose dependent with a significant increase observed at even the lowest concentration of gentamicin tested, 0.01 mM. Production of hydrogen peroxide was not increased when gentamicin was added to incubation media in which mitochondria or substrate was omitted or heat-inactivated mitochondria were used. The gentamicin-induced change in fluorescence was completely inhibited by catalase (but not by heat-inactivated catalase), indicating that the decrease in fluorescence was due to hydrogen peroxide. Thus this study demonstrates that gentamicin enhances the production of hydrogen peroxide by mitochondria. Because of their well-documented cytotoxicity, reactive oxygen metabolites may play a critical role in gentamicin nephrotoxicity.

Etching Volume Effect on the Morphology of Silicon Etched by Metal-Assisted Chemical Method

2012 ◽  
Vol 217-219 ◽  
pp. 1141-1145 ◽  
Author(s):  
Wei Wang ◽  
Li Juan Zhao ◽  
Ping Xin Song ◽  
Ying Jiu Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Formation Mechanism ◽  
Ag Nanoparticles ◽  
Hydrofluoric Acid ◽  
Chemical Method ◽  
Volume Effect ◽  
Etching Solution ◽  
Si Substrates ◽  
Si Nanostructures

Assisted by Ag nanoparticles, Si substrates were etched in aqueous solutions containing hydrofluoric acid (HF) and hydrogen peroxide (H2O2) with different volumes of etching solution. The etching morphology of Si wafers was found to be affected by the volumes. In etching solutions with smaller volume, the pores were created; in etching solutions with larger volume, the nanostructure composed of nanowires and nanopores (pores+wires nanostructure) were generated. In addition, the lengths of these Si nanostructures increased with the increase of the etching volume. Possible formation mechanism for this phenomenon was discussed.

The protective effect of melatonin on the in vitro development of yak embryos against hydrogen peroxide-induced oxidative injury

Zygote ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 118-125 ◽  
Author(s):  
Wei Peng ◽  
Mengtong Lei ◽  
Jun Zhang ◽  
Yong Zhang
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Critical Role ◽  
Underlying Mechanism ◽  
Preimplantation Embryos ◽  
Effective Antioxidant ◽  
Vitro Development ◽  
Oxidation Effect

SummaryMelatonin plays a critical role in several types of cells as an antioxidant to protect intracellular molecules from oxidative stress. The anti-oxidation effect of melatonin in yak embryos is largely unknown. We report that melatonin can protect the development of yak preimplantation embryos against oxidative stress induced by hydrogen peroxide (H2O2). Therefore, the quality of blastocysts developed from zygotes exposed to H2O2 was promoted. In addition, we observed that melatonin reduced H2O2-induced intracellular reactive oxygen species (ROS) levels and prevented mitochondrial dysfunction in zygotes. These phenomena revealed the effective antioxidant activity of melatonin to prevent oxidative stress in yak embryos. To determine the underlying mechanism, we further demonstrated that melatonin protected preimplantation embryos from oxidative damage by preserving antioxidative enzymes. Collectively, these results confirmed the anti-oxidation effect of melatonin in yak embryos that significantly improved the quantity and quality of blastocysts in the in vitro production of embryos in yaks.

scholarly journals Formation Mechanism of Bleaching Damage for a Biopolymer: Differences between Sodium Hypochlorite and Hydrogen Peroxide Bleaching Methods for Shellac

ACS Omega ◽  
2020 ◽  
Vol 5 (35) ◽  
pp. 22551-22559
Author(s):  
Kun Li ◽  
Baoshan Tang ◽  
Wenwen Zhang ◽  
Zhengjun Shi ◽  
Xinghao Tu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Formation Mechanism ◽  
Sodium Hypochlorite ◽  
Peroxide Bleaching

The Critical Role of Hepes in SIN-1 Cytotoxicity, Peroxynitrite Versus Hydrogen Peroxide

1998 ◽  
Vol 24 (4) ◽  
pp. 522-528 ◽  
Author(s):  
Elena E Lomonosova ◽  
Michael Kirsch ◽  
Ursula Rauen ◽  
Herbert de Groot
Keyword(s):  
Hydrogen Peroxide ◽  
Critical Role

scholarly journals Dual Role of Hydrogen Peroxide in Arabidopsis Guard Cells in Response to Sulfur Dioxide

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Huilan Yi ◽  
Xin Liu ◽  
Min Yi ◽  
Gang Chen
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Death ◽  
Sulfur Dioxide ◽  
Nadph Oxidase ◽  
Stomatal Closure ◽  
Critical Role ◽  
Guard Cells ◽  
Oxidase Inhibitor ◽  
Air Pollutant ◽  
Low Levels

Sulfur dioxide (SO2) is a major air pollutant and has significant impacts on plant physiology. Plant can adapt to SO2 stress by controlling stomatal movement, gene expression, and metabolic changes. Here we show clear evidences that SO2-triggered hydrogen peroxide (H2O2) production mediated stomatal closure and cell death in Arabidopsis leaves. High levels of SO2 caused irreversible stomatal closure and decline in guard cell viability, but low levels of SO2 caused reversible stomatal closure. Exogenous antioxidants ascorbic acid (AsA) and catalase (CAT) or Ca2+ antagonists EGTA and LaCl3 blocked SO2-induced stomatal closure and decline in viability. AsA and CAT also blocked SO2-induced H2O2 and [Ca2+]cyt elevation. However, EGTA and LaCl3 inhibited SO2-induced [Ca2+]cyt increase but did not suppress SO2-induced H2O2 elevation. These results indicate that H2O2 elevation triggered stomatal closure and cell death via [Ca2+]cyt signaling in SO2-stimulated Arabidopsis guard cells. NADPH oxidase inhibitor DPI blocked SO2-induced cell death but not the stomatal closure triggered by low levels of SO2, indicating that NADPH oxidase-dependent H2O2 production plays critical role in SO2 toxicity but is not necessary for SO2-induced stomatal closure. Our results suggest that H2O2 production and accumulation in SO2-stimulated plants trigger plant adaptation and toxicity via reactive oxygen species mediating Ca2+ signaling.

scholarly journals Inhibition of Connexin 26/43 and Extracellular-Regulated Kinase Protein Plays a Critical Role in Melatonin Facilitated Gap Junctional Intercellular Communication in Hydrogen Peroxide-Treated HaCaT Keratinocyte Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hyo-Jung Lee ◽  
Hyo-Jeong Lee ◽  
Eun Jung Sohn ◽  
Eun-Ok Lee ◽  
Jin-Hyoung Kim ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Intercellular Communication ◽  
Connexin 43 ◽  
Critical Role ◽  
Combined Treatment ◽  
Connexin 26 ◽  
Hacat Cells ◽  
Gap Junctional Intercellular Communication ◽  
Hacat Keratinocyte ◽  
Gap Junctional

Though melatonin was known to regulate gap junctional intercellular communication (GJIC) in chick astrocytes and mouse hepatocytes, the underlying mechanism by melatonin was not elucidated in hydrogen peroxide- (H2O2-) treated HaCaT keratinocyte cells until now. In the current study, though melatonin at 2 mM and hydrogen peroxide (H2O2) at 300 μM showed weak cytotoxicity in HaCaT keratinocyte cells, melatonin significantly suppressed the formation of reactive oxygen species (ROS) in H2O2-treated HaCaT cells compared to untreated controls. Also, the scrape-loading dye-transfer assay revealed that melatonin enhances the intercellular communication by introducing Lucifer Yellow into H2O2-treated cells. Furthermore, melatonin significantly enhanced the expression of connexin 26 (Cx26) and connexin 43 (Cx43) at mRNA and protein levels, but not that of connexin 30 (Cx30) in H2O2-treated HaCaT cells. Of note, melatonin attenuated the phosphorylation of extracellular signal-regulated protein kinases (ERKs) more than p38 MAPK or JNK in H2O2-treated HaCaT cells. Conversely, ERK inhibitor PD98059 promoted the intercellular communication in H2O2-treated HaCaT cells. Furthermore, combined treatment of melatonin (200 μM) and vitamin C (10 μg/mL) significantly reduced ROS production in H2O2-treated HaCaT cells. Overall, these findings support the scientific evidences that melatonin facilitates gap junctional intercellular communication in H2O2-treated HaCaT keratinocyte cells via inhibition of connexin 26/43 and ERK as a potent chemopreventive agent.

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