• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.235-242
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• 2007

This study was conducted to investigate the effect of aerosolized chemical sanitizers on inhibiting foodborne pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Five domestic commercial sanitizers subjected to five groups of sanitizer (chlorine-based, hydrogen peroxide-based, Iodophor-based, quaternary ammonium-based, and alcohol-based sanitizers) were aerosolized by an aerosol generator into a model cabinet and treated in laboratory media containing three pathogens for 1 h at room temperature. Aerosolized hydrogen peroxide-based and quaternary ammonium-based sanitizers were effective at inhibiting levels of E. coli O157:H7 (ca. 4-9 log reductions) whereas other aerosolized sanitizers such as chlorine-based, Iodophor-based, and alcohol-based sanitizers did not significantly reduced the levels of E. coli O157:H7. For S. typhimurium, the only aerosolized hydrogen peroxide-based sanitizer was effective and resulted in ca. 5-9 log reduction. Aerosolized hydrogen peroxide-based, Iodophor-based, and quaternary ammonium-based sanitizers significantly reduced levels of L. monocytogenes and especially, aerosolized quaternary ammonium-based sanitizer was strongly effective to kill L. monocytogenes, resulted in higher than 8.8 log reduction. And there was no special trend in inhibitory efficacy of sanitizers aerosolized by 1.6 or 2.4 MHz aerosol generators. From these results, aerosolization has great potential for use in commercial applications however it's efficacy could be very different depending on type of sanitizers.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.29-37
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• 2000

Fenton’s oxidation process is one of the most commonly applied processes to the wastewater which cannot be treated by conventional biological treatment processes. However, it is necessary to minimize the cost of Fenton’s oxidation treatment by modifying the treatment processes or other means of chemical treatment. So, as a method for the chemical oxidation of biorefractory or nonbiodegradable organic pollutants, the Photo-Fenton-Reaction which utilizes iron(11)salt. $H_2O$$_2$ and UV-light simultaneously has been proprosed. Therfore, the purpose of this study is to test a removal efficiency of dye-wastewater and treatment cost with Fenton’s and Photo-Fenton’s oxidation process. The Fe(11)/$H_2O$$_2$ reagent is referred to as the fenton’s reagent. which produces hydroxy radicals by the interaction of Fe(11) with $H_2O$$_2$. In this exoeriment, the main results are as followed; 1. The Fenton oxidation was most efficient in the pH range of 3-5. The optimal condition for initial reaction pH was 3.5 for the high CO $D_{Cr}$ & TOC-removal efficiency. 2. The removal efficiency of TOC and CO $D_{Cr}$ increased up to the molar ration between ferrate and hydrogen peroxide 0.2:1, but above that ratio removal efficiency hardly increased. 3. The highest removal efficiency of TOC and CO $D_{Cr}$ were showed when the mole ration of ferrate to hydrogen peroxide was 0.2:3.4. 4. Without pretreatment process, photo-fenton oxidation which was not absorbed UV light was not different to fenton oxidation. 5. And Fenton oxidtion with pretreatment process was similar to Fenton oxidation in the absence of coagulation, the proper dosage of F $e^{2+}$: $H_2O$$_2$ was 0.2:1 for the optimal removal efficiency of TOC or CO $D_{Cr}$ .6. Also, TOC & CO $D_{Cr}$ removal efficiency in the photo-fenton oxidation with pretreatment was increased when UV light intensity enhanced.7. Optimum light intensity in the range from 0 to 1200 W/$m^2$ showed that UV-intensity with 1200W/$m^2$ was the optimum condition, when F $e_{2+}$:$H_2O$$_2$ ratio for the highest decomposition was 0.2:2.5.EX>$_2$ ratio for the highest decomposition was 0.2:2.5.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.357-363
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• 2020

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) is known as an etiology of neurodegenerative diseases. Populus tomentiglandulosa (PT), a member of the Salicaceae family, is widely grown in Korea and has been reported to exert protective effects on cerebral ischemia by attenuating of oxidative stress and neuronal damage. In the present study, we investigated the antioxidant activity and neuroprotective effects of an ethanol extract and four fractions [n-butanol, ethyl acetate (EtOAc), chloroform, and n-hexane] of PT under in vitro and cellular systems. The extract and four fractions of PT showed 1,1-diphenyl-2-picrylhydrazyl (DPPH), •OH, and O2- radical scavenging activities in a dose-dependent manner. In particular, the EtOAc fraction of PT had the strongest DPPH, •OH, and O2- radical scavenging activities among the extract and other fractions. Therefore, we further investigated the neuroprotective effect of the EtOAc fraction of PT against oxidative stress in H2O2-induced SH-SY5Y cells. Treatment with H2O2 significantly decreased cell viability and lactate dehydrogenase (LDH) release, and it also increased the ROS levels compared to the normal group. However, treatment with the EtOAc fraction of PT significantly increased cell viability. Moreover, the EtOAc fraction of PT-treated group significantly suppressed ROS production and LDH release compared to the H2O2-induced control group. In conclusion, our findings indicated that PT had in vitro antioxidant activity and neuroprotective effects against oxidative stress. Therefore, PT could be used as a natural agent for protection against oxidative stress.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.197-205
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• 2006

Objectives: Anti-oxidants are known to prevent neuronal diseases with pathological and physiological changes such as the brain atrophy and cognitive impairment. This study was designed to investigate the protective effects of Korean ginseng on the oxidative stress induced pathologic changes, and develop new animal model for the brain atrophy. Korean ginseng has anti-oxidant, anti-aging, and protective effects on the brain ischemia. Methods : The intracerebroventricular (ICV) hydrogen peroxide ($H_2O_2$) injection into mice was conducted to generate oxidative stress. Results : The ICV $H_2O_2$ (1 M, $5\;{\mu}l$ injection did not induce either convulsion or death in the acute phase. At the end of second week, cognitive impairment and pathologic change of the brain were observed. The massive brain atrophy was found in the $H_2O_2-injected$ mice, especially in the hippocampus and thalamus. Treatment with Korean ginseng showed a protective effect against the brain atrophy. The $H_2O_2$ injected mice revealed cognitive impairment in the passive avoidance test, and Korean ginseng alleviated cognitive impairment. Conclusion : The results indicate that Korean ginseng has a protective effect on the oxidative stress-induced neuronal damages.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.3
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• pp.98-104
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• 2011

To evaluate the physioactivity of Salicornia herbacea L. (SH), which are obtained from Sunchon bay as wild plants, an SH extract was prepared by freeze drying to obtain SH, and by cold drying to obtain SH. For the evaluation of their bioactivities, cell viability and antioxidative effect were measured. The XTT assay was adopted to measure cell viability after C6 glioma cells were treated with various concentrations of reactive oxygen species (ROS) and hydrogen peroxide ($H_2O_2$) for 8 hours. The DPPH-radical scavenging activity was also measured for the antioxidative effect. In this study, the $XTT_{50}$ value of $H_2O_2$ was determined at $30{\mu}M$ which was highly toxic based on the cytotoxic criteria by Borenfreund and Puerner. The protective effect of SH extract significantly increased cell viability compared with $H_2O_2$-treated group. Its antioxidative effect showed a significant DPPH-radical scavenging activity at concentrations of $1-100{\mu}g/mL$, while SH extract showed highly a DPPH-radical scavenging activity at only $100{\mu}g/mL$. From these results, $H_2O_2$ was highly toxic in cultured C6 glioma cells, and SH extract was effective in the prevention of cell damage by its antioxidative effect.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.689-697
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• 2005

Hydrogen peroxide is a reservoir of OH radical which is the powerful oxidant in the atmosphere. Therefore, the status of the oxidizing atmosphere could be reflected on the concentration of $H_{2}O_{2}$. In this study, the distribution of $H_{2}O_{2}$ was determined during the intensive aircraft measurements over the Yellow sea in March, December 2002, April, November 2003 and March, October 2004. Flights covered from $124^{circ}E\;to\;129^{circ}E\;and\;35^{circ}N\;to\;37^{circ}N$, and extending to 3,000 m. The flight patterns were set properly to assess the altitudinal and longitudinal distribution for $H_{2}O_{2}$. $H_{2}O_{2}$ was extracted onto aqueous solution using a continuously flowing glass coil and analyzed by a high performance liquid chromatography (HPLC) accompanied with a fluorescence detector using postcolumn enzyme derivatization. Mixing ratios of $O_{3},\;NO_{x}\;and\;SO_{2}$ were measured in real time by commercial analysis instruments. Along the heights, the maximum concentration of $H_{2}O_{2}$ appeared around 1,500 m then gradually decreased with increasing altitude. The vertical behavior of ozone showed the similar trend to $H_{2}O_{2}$. The mean mixing ratio of $NO_{x}$ was about 2 ppbv and not showed clear vertical distribution patterns. The mean value of was the same as $NO_{x}$ however $SO_{2}$ appeared extreme concentration in low altitude. $H_{2}O_{2}\;and\;O_{3}$ showed even longitudinal distribution however $NO_{x}$ mixing ratio in land ($127^{circ}E$) was much higher than over the sea. $SO_{2}$ rather decreased with increasing longitude. $H_{2}O_{2}$ was in inverse proportion to $NO_{x}$ in spring and summer and $SO_{2}$ in spring, which indicated its significant role to NO and $SO_{2}$ oxidation pathways.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_3
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• pp.127-137
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• 2001

The sonochemical Process has been applied as a treatment method and was investigated its effect on the decomposition of humic substances(HS). The reaction kinetics and mechanisms in the Process of sonochemical treatment for humic substances(HS) in wastewater have also been discussed. It was observed that the metal ions such as Fe(II) and Mn(II) showed catalytic effects, while Al(III), Ca(II), and Mg(II) had inhibitory effects on the decomposition of humic substances in sonochemical reaction with hydrogen peroxide. Experimental results also showed factors such as hydrogen peroxide dose affected the formation of disinfection by-products. Two trihalomethanes, chloroform and dichlorobromomethane were formed as major disinfection by-products during chlorination. The mechanism of radical reaction is controlled by an oxidation process. The radicals are so reactive that most of them are consumed by HS radicals and hydroxyl radicals can be acted on organic solutes by hydroxyl addition, hydrogen abstraction, and electron transfer. The depolymerization and the radical reaction of HS radicals appear to occur simultaneously. The final steps of the reaction are the conversion of organic acids to carbon dioxide.

• BMB Reports
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• v.44 no.3
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• pp.165-169
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• 2011

Excess free iron generates oxidative stress that may contribute to the pathogenesis of various causes of neurodegenerative diseases. In this study, we assessed the modification of ferritin induced by $H_2O_2$. When ferritin was incubated with $H_2O_2$, the degradation of ferritin L-chain increased with the $H_2O_2$ concentration whereas ferritin H-chain was remained. Free radical scavengers, azide, thiourea, and N-acetyl-$_L$-cysteine suppressed the $H_2O_2$-mediated ferritin modification. The iron specific chelator, deferoxamine, effectively prevented $H_2O_2$-mediated ferritin degradation in modified ferritin. The release of iron ions from ferritin was increased in $H_2O_2$ concentration-dependent manner. The present results suggest that free radicals may play a role in the modification and iron releasing of ferritin by $H_2O_2$. It is assumed that oxidative damage of ferritin by $H_2O_2$ may induce the increase of iron content in cells and subsequently lead to the deleterious condition.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.404-410
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• 2005

The pH efforts on the removal of 1,4-dioxane and the biodegradobility enhancement of dioxane contaminated water were investigated using $O_3/H_2O_2$ baled advanced oxidation process. Experiments were conducted using a bubble column reactor under different initial pH. The $O_3/H_2O_2$ process effectively converted 1,4-dioxane to more biodegradable intermediates which had a maximum $BOD_5$ enhancement at pH 11 within the experimental range, precisely, when the initial pH increased, $BOD_5$ enhanced. However, in case of removal efficiencies of 1,4-dioxane during $O_3/H_2O_2$ oxidation the optimum condition was shown at pH 9 compared with pH 6 and 11. TOC and COD values were not largely changed for all reaction time. From the results of 1,4-dioxane removal efficiency, TOC, COD, and $BOD_5$ enhancement with reaction time, it was surely observed that 1,4-dioxane was just converted to biodegradable materials, not completely oxidized to carbon dioxide.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.153.1-153.1
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• 2003

Oxidative stress induced by reactive oxygen intermediates (ROIs) has been implicated in a variety of human diseases including cancer, diabetes, rheumatoid arthritis and neurodegenerative disorders. Hydrogen peroxide ($H_2O_2$), a representative ROI which is produced during the cellular redox process, can cause cell death via apoptosis and/or necrosis depending on its concentrations. l5-Deoxy-$D^{12, 14}$ prostaglandin $J_2$ (15d-$PGJ_2$), a dehydration product of prostaglandin $D_2$, has been reportd to possess a number of biological activities such as anti-inflammatory, anticarcinogenic, and antioxidative properties. (omitted)