• Mycobiology
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• v.39 no.1
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• pp.64-66
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• 2011

Most fungi possess several hydrogen peroxide-generating enzymes, glucose oxidase and pyranose oxidase. Pyranose oxidase can use glucose as its substrate to generate hydrogen peroxide. White rot fungi, which degrade diverse recalcitrant compounds, contain lignin-degrading enzymes, and lignin peroxidase and manganese peroxidase require hydrogen peroxide for their enzymatic reactions. In this study, we isolated a cDNA fragment of pyranose oxidase from Phlebia tremellosa using PCR and examined its expression under the degradation conditions of diethylphthalate (DEP). Pyranose oxidase expression was enhanced up to 30% by the addition of DEP, and this result supports the possible involvement of pyranose oxidase in the degradation of recalcitrant compounds.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1361-1362
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• 2007

There is great interest in the applicability of electrogenerated hydrogen peroxide to a wide variety of industrial processes, usually involving oxidation of organics. Hydrogen peroxide is now employed for the bleaching of mechanical pulp and the bleaching of chemical pulp in the pulp and paper industry, thus displacing the traditional alkaline treatments with chlorine-based chemicals. This psper reperts a comparative study of $H_{2}O_{2}$ electogeneration on gas-diffusion electrode in divided cell with several $Nafion^{(R)}$ protonexchange membranes, Russian cation-exchange membrane MK-40 and SPEEK membrane. The influence of different PEMs on electrochemical cell voltage, current efficiency and energy consumption of hydrogen peroxide electrogeneration has been stadied.

• The Korea Journal of Herbology
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• v.26 no.2
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• pp.17-23
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• 2011

Objectives : This study aims at examining the effect of the fermentative extract of root of Sophorae Radix on the immuno-modulating activity. Methods : Cell viabilities were measured by MTT assay. Effect of SFS on nitric oxide(NO), hydrogen peroxide production from RAW 264.7 cells was accessed by Griess reagent assay. Effect of SFS on productions of inflammatory cytokines such as TNF-${\alpha}$, IL-6 in LPS-induced RAW 264.7 cells was accessed by a multiplex bead array assay based on xMAP technology. Results : The results of the experiment are as follows. 1. As a result of carrying out MTT assay to check the cellular toxicity of the fermentative extract of Sophorae Radix. There was not any excessive toxicity to the macrophage when the fermentative extract of root of Sophorae Radix was treated in different concentrations. 2. The fermentative extract of Sophorae Radix increased the generation of hydrogen peroxide in the macrophage and significantly restored the suppression of the generation of the hydrogen peroxide in the macrophage induced by LPS. 3. The fermentative extract of Sophorae Radix reduced the generation of NO in the macrophage and significantly suppressed the increase of the generation of NO in the macrophage induced by LPS. 4. The fermentative extract of Sophorae Radix significantly decreased the amount of TNF-${\alpha}$ generated in the macrophage induced by LPS when it was $25{\mu}g/mL$ or higher. Conclusion : These results suggest that SFS has anti-inflammatory moiety related with its inhibition of NO, hydrogen peroxide, TNF-${\alpha}$, IL-6, in macrophage led by LPS.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.3-12
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• 2001

During ozonation process, the hydroxyl radical generation rates were measured under different experimental conditions (ozone feed rate, nitrobenzene concentration, hydroxyl radical scavenger, pH, HO$_2$O$_2$/O$_3$ etc.) Nitrobenzene could be decomposed by hydroxyl radical rather than ozone only and nitrobenzene decomposition rate was expressed with functions of ozone and nitrobenzene concentration. The rate was decreased as the hydroxyl radical scavenger concentration was increased, and all results were followed pseudo first-order reaction. Using a competitive method, hydroxyl radical generation rate was measured with probe compound and scavenger. It was proportional to ozone concentration, and 0.24mo1 of hydroxyl radical was produced with 1mol of ozone. Under different pH conditions, hydroxyl radical generation rates were measured (pH 10.2 (0.91Ms$^{-1}$ ) > pH 7.3 (0.72Ms$^{-1}$ ) > pH 5.6 (0.67Ms$^{-1}$ ) > pH 3.4 (0.63Ms$^{-1}$ )) showing higher generation rate at high pH values. Addition of hydrogen peroxide promoted the generation rate of hydroxyl radical. Considering the results of pH experiments and addition of hydrogen peroxide experiments, the hydroxyl radical generation rate was 1.6 times higher in hydrogen peroxide solution than in high pH solution, indicating addition of hydrogen peroxide is better promoter to produce the hydroxyl radical in ozonation. These results could be applied to AOPs to remediate the contaminated wastewater and groundwater.

• Toxicological Research
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• v.16 no.3
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• pp.179-185
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• 2000

Zinc is known to generate reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. Here in, we demonstrated that zinc decreased the viability of C6 glial cells in a time and dose-dependent manner, which was revealed as apoptosis characterized by ladder-pattern fragmentation of genomic DNA. chromatin condensation and DNA fragmentation in Hoechst dye staining. Zinc-induced apoptosis of C6 glial cells was prevented by the addition of catalase and antioxidants including reduced glutathione (GSH), N-acetyl-L-cysteine (NAC) and pyrrolidinedithiocarbamate (PDTC). Wefurther confirmed that zinc decreased intrac-ellular levels of GSH and generated $H_2O_2$in C6 glial cells. Moreover, antioxidants also decreased the generation of zinc-induced $H_2O_2$ in C6 glial cells. These data indicated that zinc-induced the apoptotic death of C6 glial cells via generation of reactive oxygen species such as $H_2O_2$.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.111-117
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• 2013

Objectives : This research aimed at studying the immuno modulating activity of Fermented Epimedii Herba (EHS). Method : The impacts on the cell viability, hydrogen peroxide and nitric oxide (NO) generation in cells, and cytokines such as tumor necrosis factor-alpha (TNF-${\alpha}$), interleukin (IL)-6, IL-$1{\beta}$, monocyte chemoattractant protein-1 (MCP-1) level have been measured by using Raw 264.7 cells with the specimen EHS as the fermented extract of Epimedii Herba with Saccharomyces cerevisiae STV89. Result : As a result of MTT assay to confirm the cytotoxicity of extracts from fermented Epimedii Herba, the toxicity was not excessively induced in Raw 264.7 cells when EHS were processed by concentration. EHS increased hydrogen peroxide generation in Raw 264.7 cells. EHS suppressed NO generation in Raw 264.7 cells while they significantly suppressed the increase of NO generation induced by LPS in macrophage. EHS significantly decreased the generation amount of TNF-${\alpha}$ and IL-6 induced by LPS in Raw 264.7 cells at $25{\mu}g/mL$ or more. Conclusion : It appeared that the fermented extract of Epimedii Herba manufactured from Epimedii Herba significantly has the immuno modulating acitivity as it did not excessively trigger cytotoxicity to Raw 264.7 cells, increased hydrogen peroxide generation in Raw 264.7 cells, decreased NO generation in macrophage, and especially, suppressed both TNF-${\alpha}$ and IL-6 generation in macrophage induced by LPS.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.524-527
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• 2000

An electroenzymatic system to oxidize veratryl alcohol of on electrodes with in-situ generated hydrogen peroxide was studied. We investigated hydrogen peroxide generation, current efficiency, and veratryl alcohol oxidation in the electrode system at various conditions. The reaction rates of veratryl alcohol oxidation were compared in an electrochemical, an electroenzymatic, and an usual biochemical systems to prove the concept of electroenzymatic oxidation.

• Toxicological Research
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• v.17 no.4
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• pp.249-253
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• 2001

Fumonisin B1, a mycotoxin, is thought to induce esophageal cancer in humans and apoptosis in animal cells by inhibiting ceramide synthase. Dumonisin Bl may also generate reactive oxygen species directly or indirectly, leading to DNA damage and lipid peroxidation. In this study, a DNA fragmentation assay, dichlorofluorescein (DCF) analysis, and single cell gel electrophoresis (SCGE) were used to investigate the involvement of cellular free radicals, specifically hydrogen peroxide, in the DNA damaging activity of fumonisin B1. From an in vitro DNA fragmentation assay, E. coli DNA, damage by fumonisin Bl was increased by the addition of superxide dismutase (SOD) and decreased by catalase. SCGE and DCF analysis in vivo showed that the nuclear DNA damage and intracellular free radicals in cultured rat hepatocytes treated with fumonisin B1 were increased with the concentration of fumonisin Bl . DNA damage and free radical generation were inhibited by the addition of catalase. Fumonisin Bl , in the presence of SOD, produces hydrogen peroxide causing oxidative DNA damage and protein malfunction, leading to genotoxicity and cytotoxicity of the toxin.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1998.10a
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• pp.1-1
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• 1998

Advanced (Chemical) oxidation processes (AOP) differ from most conventional ones in that hydroxyl radical(OH.) is considered to be the primary oxidant. Hydroxyl radicalcan react non-selectively with a great number of organic and inorganic chemicals. The typical rate constants of true hydroxyl radical reactions are in the range of between 109 to 1012 sec-1. Many processes are possible to generate hydroxyl radical. These include physical and chemical methods and their combinations. Physical means involves the use of high energy radiation such as gamma ray, electron beam, and acoustic wave. Under an applied high energy radiation, water molecules can be decomposed to yield hydroxyl radicals or aqueous electrons. Chemical means include the use of conventional oxidants such as hydrogen peroxide and ozone, two of the most efficient oxidants in the presence of promoter or catalyst. Hydrogen peroxide in the presence of a catalyst such as divalent iron ions can readily produce hydroxyl radicals. Ozone in the presence of specific chemical species such as OH- or hydrogen peroxide, can also generate hydroxyl radicals. Finally the combination of chemical and physical means can also yield hydroxyl radicals. Hydrogen peroxide in the presence of acoustic wave or ultra violet beam can generate hydroxyl radicals. The principles for hydroxyl radical generation will be discussed. Recent case studied of AOP for water treatment and other environmental of applications will be presented. These include the treatment of contaminated soils using electro-Fenton, lechate treatment with conventional Ponton, treatment of coal for sulfur removal using sonochemical and the treatment of groundwater with enhanced sonochemical processes.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1644-1646
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• 2009