• Asian Journal of Atmospheric Environment
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• v.11 no.1
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• pp.29-32
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• 2017

Ozone concentration in Tokyo Metropolitan area is one of the most serious issues of the local air quality. Tropospheric ozone is formed by radical reaction including volatile organic compound (VOC) and nitrogen oxides ($NO_x$). Reduction of the emission of reactive VOC is a key to reducing ozone concentrations. VOC is emitted from anthropogenic sources and also from vegetation (biogenic VOC or BVOC). BVOC also forms ozone through $NO_x$ and radical reactions. Especially, in urban area, the BVOC is emitted into the atmosphere with high $NO_x$ concentration. Therefore, trees bordering streets and green spaces in urban area may contribute to tropospheric ozone. On the other hand, not all trees emit BVOC which will produce ozone locally. In this study, BVOC emissions have been investigated (terpenoids: isoprene, monoterpenes, sesquiterpenes) for 29 tree species. Eleven in the 29 species were tree species that did not emit BVOCs. Three in 12 cultivars for future planting (25 %) were found to emit no terpenoid BVOCs. Eight in 17 commonly planted trees (47%) were found to emit no terpenoid BVOC. Lower-emitting species have many advantages for urban planting. Therefore, further investigation is required to find the species which do not emit terpenoid BVOC. Emission of reactive BVOC should be added into guideline for the urban planting to prevent the creation of sources of ozone. It is desirable that species with no reactive BVOC emission are planted along urban streets and green areas in urban areas, such as Tokyo.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.487-490
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• 2008

Temperature programmed oxidation (TPO) is used to characterize coke species deposited on commercial nickel catalyst, C11-PR during propane pre-reforming. Propane pre-reforming performed under various condition, S/C from 1.5 to 2.5 and temperature from $350^{\circ}C$ to $450^{\circ}C$. There are three kinds of coke species detected by TPO: (i) reactive coke, (ii) coke deposited on metal site and (iii) coke deposited on acid support. Coke deposited on metal and support are minimized although reactive coke is generated at temperature of $400^{\circ}C$ and S/C of 2.0. Reactive coke is expected to remove easily below temperature of $200^{\circ}C$. Therefore, optimized pre-reforming condition for propane is $400^{\circ}C$ and S/C of 2.0.

• BMB Reports
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• v.46 no.11
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• pp.555-560
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• 2013

Acrolein is the most reactive aldehydic product of lipid peroxidation and is found to be elevated in the brain when oxidative stress is high. The effects of acrolein on the structure and function of human Cu,Zn-superoxide dismutase (SOD) were examined. When Cu,Zn-SOD was incubated with acrolein, the covalent crosslinking of the protein was increased, and the loss of enzymatic activity was increased in a dose-dependent manner. Reactive oxygen species (ROS) scavengers and copper chelators inhibited the acrolein-mediated Cu,Zn-SOD modification and the formation of carbonyl compound. The present study shows that ROS may play a critical role in acrolein-induced Cu,Zn-SOD modification and inactivation. When Cu,Zn-SOD that has been exposed to acrolein was subsequently analyzed by amino acid analysis, serine, histidine, arginine, threonine and lysine residues were particularly sensitive. It is suggested that the modification and inactivation of Cu,Zn-SOD by acrolein could be produced by more oxidative cell environments.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.69-69
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• 2003

There are now increasing evidences that free radicals and reactive oxygen species are involved in a variety of pathological events. Reactive Oxygen Species (ROS) are produced during normal cellular function. ROS lead to lipid peroxidation, massive protein oxdiation and degradation. Under normal conditions, antioxidant are substnaces that either directly or indirectly protect cell against adverse effect of ROS. several biologically important compound include ${\beta}$-carotene, taruine and flavonoids reported have antioxidant function. The various antioxidant either scavange superoxide and free radicals or stimulate the detoxification mechanisms within cells resulting in increased detoxification of free radicals formation and thus in prevention of many pathophysiologic processes. This study carried out to investigate the antioxidant activity of flavonoids, myricetin with other antioxidants, ${\beta}$-carotene and taurine on B16Fl0. In order to investigate the efficacy of antioxidant activity, we measured cell viability, antioxidant enzyme activity (SOD, GPX, CAT) and intracellular reactive oxygen intermediate (ROI). In this results, we show that these flavonoids with other antioxidant substrates are increased antioxidant activity level.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2000.04a
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• pp.15-16
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• 2000

Transient forebrain ischemia results in delayed neuronal death in the CA1 region of the hippocampus after injury, which is, at least in part, a consequence of excessive generation of reactive oxygen species. Previous in vitro studies using cell cultures or brain slices have demonstrated that phospholipase D (PLD) in the nervous system is involved in the signaling mechanism in response to a variety of agonists. Several recent studies have shown that reactive oxygen species stimulate phospholipase D (PLD) activity in several kinds of cells. Therefore, this raises the possibility that PLD activity is enhanced in the ischemic brain. Meanwhile, osteopontin (OPN) was initially identified as a sialoglycoprotein in bone, but has since been found in various tissues. Although not much is known about its function, OPN seems to play an important role in inflammation and tissue repair. Recently, it was reported that OPN was upregulated in the activated microglia after focal brain ischemia, suggesting that OPN might play a role in wound healing after a focal stroke.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3295-3300
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• 2013

Acrolein (ACR) is a well-known carbonyl toxin produced by lipid peroxidation of polyunsaturated fatty acids, which is involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). In Alzheimer's brain, ACR was found to be elevated in hippocampus and temporal cortex where oxidative stress is high. In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with ACR. When cytochrome c was incubated with ACR, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in ACR-treated cytochrome c. Reactive oxygen species scavengers and iron specific chelator inhibited the ACR-mediated cytochrome c modification and carbonyl compound formation. Our data demonstrate that oxidative damage of cytochrome c by ACR might induce disruption of cyotochrome c structure and iron mishandling as a contributing factor to the pathology of AD.

• Biomedical Science Letters
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• v.23 no.2
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• pp.128-132
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• 2017

Streptozotocin (STZ), bisphenol A (BPA), and diethylstilbestrol (DES) are known as endocrine disruptors, occurs oxidative stress in animal cells. Generally, oxidative stress induces reactive oxygen species (ROS) and lipid peroxidation of sperm and lead to decreased viability and fertility in pigs. Therefore, we investigated the influence of STZ, BPA and DES on ROS production and lipid peroxidation on boar sperm. Collected sperm were incubated with semen extender containing $10{\mu}M\;STZ$, $10{\mu}M\;BPA$ and $20{\mu}M\;DES$ for 3, 6 and 9 hours. Intracellular ROS and lipid peroxidation of sperm were analyzed by 2', 7'-dichlorofluorescein diacetate and malondialdehyde methods. The results show that, intracellular ROS was not significantly different among the all treatments, but lipid peroxidation was significantly increased in STZ group at 3 hour after incubation with boar sperm (P<0.05). These results suggest that STZ stimulates lipid peroxidation more than ROS production and may exert a negative effect on sperm fertility.

• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.331-337
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• 2009

Purpose: Interleukin (IL)-8 is one of pro-inflammatory cytokines. Reactive oxygen species (ROS) are reduced metabolites of $O_2$. Aggregatibacter actinomycetemcomitans is one of representative periodontopathogens. To investigate the role of A. actinomycetemcomitans in IL-8 expression of periodontal ligament (PDL) cells, we estimated the production of IL-8 and ROS in A. actinomycetemcomitans treated PDL cells. Methods: The IL-8 production was determined by enzyme-linked immunosorbent assay. The ROS production was estimated using H2DCFDA and FACS. Results: A. actinomycetemcomitans increased the production of IL-8 and ROS at 10, 100, and 500 multiplicity of infection. N-acetylcysteine, an antioxidant of ROS, down-regulated the production of IL-8 induced by A. actinomycetemcomitans. Conclusions: These results suggest that A. actinomycetemcomitans induces IL-8 production and ROS may act as a mediator in this process.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.4
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• pp.379-383
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• 2014

The purpose of this study is to investigate the effects of silkworm extracts (SWE) on reactive oxygen species formation in mice (C57BL/6). Mice were administrated intraperitoneally with SWE (20 mg/kg/day) for 14 days. All animals were sacrificed 24 hours after the last SWE treatment and then extracted the blood and brain tissue in mouse. The researcher measured several parameters related to reactive oxygen species formation, malondialdehyde (MDA) and hydrogen peroxide ($H_2O_2$) contents in serum, whole brain, cerebral cortex and cerebellum. The results showed that MDA content of pre-SWE treatment was decreased significantly in serum, mitochondrial and cytosolic fraction of whole brain and cerebellum (P<0.01). The $H_2O_2$ content of pre-SWE treatment was decreased significantly in mitochondrial fraction of whole brain, cerebral cortex and cerebellum (P<0.01). These results suggest that SWE plays an important role for inhibition of oxidative damage of cells as well as antioxidant effect, aging delay and cells protected from irradiation.

• Natural Product Sciences
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• v.19 no.2
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• pp.127-136
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• 2013

Ionizing radiation, including that evoked by gamma (${\gamma}$)-rays, induces oxidative stress through the generation of reactive oxygen species, resulting in apoptosis, or programmed cell death. This study aimed to elucidate the radioprotective effects of hyperoside (quercetin-3-O-galactoside) against ${\gamma}$-ray radiation-induced apoptosis in Chinese hamster lung fibroblasts, V79-4 and demonstrated that the compound reduced levels of intracellular reactive oxygen species in ${\gamma}$-ray-irradiated cells. Hyperoside also protected irradiated cells against DNA damage (evidenced by pronounced DNA tails and elevated phospho-histone H2AX and 8-oxoguanine content) and membrane lipid peroxidation. Furthermore, hyperoside prevented the ${\gamma}$-ray-provoked reduction in cell viability via the inhibition of apoptosis through the increased levels of Bcl-2, the decreased levels of Bax and cytosolic cytochrome c, and the decrease of the active caspase 9 and caspase 3 expression. Taken together, these results suggest that hyperoside defend cells against ${\gamma}$-ray radiation-induced apoptosis by inhibiting oxidative stress.