• 제목/요약/키워드: Hydroxyl Radical

검색결과 901건 처리시간 0.031초

Characteristics of Nonthermal Plasma Source in Various Liquids

  • Lim, Seung-Ju;Min, Boo-Ki;Taylor, Nathan;Kim, Tae-Gyu;Kim, Hyeong-Seok;Yang, Seon-Pil;Jung, Jin-Yong;Han, Jin-Hyun;Lee, Jong-Yong;Kang, Seung-Oun;Choi, Eun Ha
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.259.1-259.1
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    • 2014
  • Recently non-thermal plasma has been frequently applied to various research fields. The liquid plasma have received much attention lately because of interests in surgical and nanomaterial synthesis applications. Especially, intensive researches have been carried out for non-thermal plasma in liquid by using various electrode configurations and power supplies. We have developed a bioplasma source which could be used in a liquid, in which outer insulator has been covered onto the outer electrode. Also we have also put an insulator between the inner and outer electrode. Based on the surface discharge mode, the nonthermal bioplasma has been generated inside a liquid by using an alternating current voltage generator with peak voltage of 12 kV under driving frequency of 22 KHz. Here the discharge voltage and current have been measured for electrical characteristics. Especially, We have measured discharge and optical characteristics under various liquids of deionized (DI) water, tap water, and saline by using monochromator. We have also observed nitric oxide (NO), hydrogen peroxide (H2O2), and hydroxyl (OH) radical species by optical emission spectroscopy during the operation of bioplasma discharge inside various kinds of DI water, tap water, and saline. Here the temperature has been kept to be $40^{\circ}C$ or less when discharge in liquid has been operated in this experiment. Also we have measured plasma temperature by high speed camera image and density by using either H-alpha or H-beta Stark broadening method.

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초석잠 부위별 영양성분 및 항산화효과 (Nutritional Components and Antioxidant Activities of Various Stachys Sieboldii Miq Parts)

  • 김연경;손희경;이재준
    • 한국지역사회생활과학회지
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    • 제28권2호
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    • pp.203-215
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    • 2017
  • This study was carried out to compare the major nutrient components and antioxidant activities of Stachys sieboldii Miq leaf and root powders. For proximate compositions, crude protein and crude fat contents of leaf powder were higher than those of root powder, whereas contents of crude ash and carbohydrates were lower in leaf powder. The content of glutamic acid was greater in amino acids of leaf and root powders, and contents of total amino acids and essential amino acids were higher in leaf powder compared with root powder. Root powder contained a higher level of total unsaturated fatty acids than leaf powder. Total contents of organic acids were higher in leaf powder; tartaric acid was the major organic acid in leaf powder, and malic acid was the major organic acid in root powder. The content of vitamin A was higher in leaf powder than in root powder. However, vitamin E content was higher in root powder than in leaf powder. Total mineral contents of leaf powder were higher than those of root powder, and mineral contents of leaf and root powders were in the order of K>Ca>Mg. Extract yields of leaf and root powders were 27.21% and 58.51%, respectively. Total polyphenols and total flavonoids of leaf extract were 236.35 mg/g and 1.90 mg/g, respectively, which were higher than those of root extract. The $IC_{50}$ values of leaf and root ethanol extracts based on DPPH hydroxyl scavenging were 0.69 mg/mL and 5934.31 mg/mL, respectively, and antioxidative activities of ethanol extracts from all Stachys sieboldii Miq parts dose-dependently increased. These results suggest that Stachys sieboldii Miq can be recommended as an edible functional food material.

동전기-펜턴 공정을 이용한 phenanthrene 오염토양의 정화 (Electrokinetic-Fenton Process for Removal of Phenanthrene)

  • 양지원;박지연;김상준;이유진;기대정
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제9권1호
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    • pp.47-53
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    • 2004
  • 본 연구에서는 동전기-펜턴 공정을 이용한 phenanthrene 오염토양 정화의 타당성을 확인하기 위해서, 토양 시스템 내에서 전기삼투흐름에 의한 과산화수소의 이동과 펜턴유사 반응에 의한 phenanthrene의 산화분해 양상을 살펴보았다. 10 mA와 5 mA의 두 가지 전류 조건 중에서, 10 mA일 때 더 높은 전압경사와 전기삼투유량이 관찰되었다. 높은 전기삼투유량은 토양 내로 많은 양의 과산화수소가 이동한 것을 의미하므로, phenanthrene 제거효율이 전기삼투유량이 증가함에 따라 증가한 것으로 판단된다. 동전기 정화기술만을 이용한 토양 세척에 의해 7일간의 가동기간 동안 8.5%의 phenanthrene이 제거되었다. Phenanthrene을 직접 산화분해하기 위하여 양극 전극조를 통하여 과산화수소 용액을 토양에 공급한 경우에는 14일 동안 최고 95.6%의 제거효율을 얻을 수 있었다. 실험 종료 후 95.6%의 제거효율을 나타낸 토양시료를 분석한 결과 phenanthrene의 중간산물이 거의 관찰되지 않음으로써, 과산화수소의 연속적인 주입을 통하여 가동기간 중간에 생성된 중간산물들이 저분자 물질로 산화분해 되었거나 물과 이산화탄소로 분해된 것으로 추정된다.

정향 추출물의 항산화.항혈소판 응집효과 및 혈전 용해능 탐색 (Screening of Antioxidative, Anti-platelet Aggregation and Anti-thrombotic Effects of Clove Extracts)

  • 양영이;이민자;이혜숙;박원환
    • 동의생리병리학회지
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    • 제25권3호
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    • pp.471-481
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    • 2011
  • Clove has been frequently used as anti-diabetic, anti-microbial, anti-inflammatory, anesthetic drug and remedies for stomachache by coldness. In this study, the antioxidant activity of extract from Clove was studied in vitro methods by measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on $Cu^{2+}$-induced human LDL oxidation. Anti-platelet aggregation and anti-thrombotic effects of Clove extracts were studied ex vivo methods by mesuring the inhibitory effect on thrombin induced platelet aggregation and the fibrinolytic activity. The Clove extracts were found to have a potent scavenging activity, as well as an inhibitory effect on LDL oxidation in vitro. Moreover Clove extracts were exhibited remarkable inhibitory effect on platelet aggregation and fibrinolytic activity. In conclusion, the Clove extracts have anti-oxidative and anti-atherosclerotic effects in vitro and ex vivo system, which can be used for developing pharmaceutical drug against oxidative stress and atherosclerosis.

GLEDITSIAE SPINA 에탄올 추출물 및 분획물이 산화적 스트레스와 human LDL 산화억제에 미치는 영향 (Preventive Effects of GLEDITSIAE SPINA Ethanol Extracts and its Fraction on Oxidative Stress and Human LDL Oxidation)

  • 김혁;이민자;이혜숙;정현정;최성규;이창섭;박원환
    • 동의생리병리학회지
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    • 제23권3호
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    • pp.631-638
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    • 2009
  • GLEDITSIAE SPINA (GS) has been used as folk remedies traditionally for treatment of antiphlogistic and antifebrile agents. An ethanol extract and its fraction of GS were assessed to determine the mechanism of its antioxidant activity. Also, inhibitory effect of extract from GS and its fraction measuring the inhibitory effect on $Cu^{2+}$-induced human low-density lipoprotein (LDL) oxidation. GS ethanol extract and its fraction exhibited a concentration-dependent reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging activities, including trolox equivalent antioxidant capacity (TEAC), OPPH radical, superoxide anion, hydroxyl radicals, peroxynitrite and nitric oxide, using different assay systems. Furthermore, the GS ethanol extract and its fraction showed dose-dependent protection of LDL oxidation induced by $CuSO_4$. In addition, the GS ethanol extract and its fraction were characterized as containing a high amount of total phenolics. These results suggest that GS ethanol extract and its fraction might be helpful for preventing oxidative stress and protecting LDL oxidation.

Fucoxanthin Protects Cultured Human Keratinocytes against Oxidative Stress by Blocking Free Radicals and Inhibiting Apoptosis

  • Zheng, Jian;Piao, Mei Jing;Keum, Young Sam;Kim, Hye Sun;Hyun, Jin Won
    • Biomolecules & Therapeutics
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    • 제21권4호
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    • pp.270-276
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    • 2013
  • Fucoxanthin is an important carotenoid derived from edible brown seaweeds and is used in indigenous herbal medicines. The aim of the present study was to examine the cytoprotective effects of fucoxanthin against hydrogen peroxide-induced cell damage. Fucoxanthin decreased the level of intracellular reactive oxygen species, as assessed by fluorescence spectrometry performed after staining cultured human HaCaT keratinocytes with 2',7'-dichlorodihydrofluorescein diacetate. In addition, electron spin resonance spectrometry showed that fucoxanthin scavenged hydroxyl radical generated by the Fenton reaction in a cell-free system. Fucoxanthin also inhibited comet tail formation and phospho-histone H2A.X expression, suggesting that it prevents hydrogen peroxide-induced cellular DNA damage. Furthermore, the compound reduced the number of apoptotic bodies stained with Hoechst 33342, indicating that it protected keratinocytes against hydrogen peroxide-induced apoptotic cell death. Finally, fucoxanthin prevented the loss of mitochondrial membrane potential. These protective actions were accompanied by the down-regulation of apoptosis-promoting mediators (i.e., B-cell lymphoma-2-associated ${\times}$ protein, caspase-9, and caspase-3) and the up-regulation of an apoptosis inhibitor (B-cell lymphoma-2). Taken together, the results of this study suggest that fucoxanthin defends keratinocytes against oxidative damage by scavenging ROS and inhibiting apoptosis.

고지방 식이로 유도된 비만 흰쥐에서 해당근에서 분리된 Euscaphic Acid 및 Tormentic Acid의 효과 (Inhibitory Effect of Euscaphic Acid and Tormentic Acid from the Roots of Rosa rugosa on High Fat Diet-Induced Obesity in the Rat)

  • 박희준;남정환;정현주;이명선;이경태;정민화;최종원
    • 생약학회지
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    • 제36권4호통권143호
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    • pp.324-331
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    • 2005
  • The roots of Rosa rugosa have been used to treat diabetes mellitus in the folkloric society of Korea. To demonstrate the active component for the rat obesity induced by high fat diet for 6 weeks, the phytochemical fractionation and the pharmacological activity test were performed on this crude drug. It was shown that the methanolic extract and its EtOAc fraction inhibited the weight increase of the rat body, abdominal fat pad and hyperlipidemia at 200 mg/kg dose. Further, the triterpenoids, euscaphic acid and tormentic acid, isolated from R. rugosa roots were active at 30 mg/kg in the same assay. The two components shifted serum total-, HDL, and LDL-cholesterol levels toward the values of the unteated group, suggesting that the active compounds has hypolipidemic effects. The rats fad euscaphic acid and tormentic acid also reduced thiobarbituric acid-reactive substance (TBARS) and hydroxyl radical in the rat blood and increased superoxide dismutase activity compared to the control. TBARS values and carbonyl contest of the hepatic protein were reduced by treatment with the two triterpenoids. Antioxidative enzyme (SOD, glutathione peroxidase, and catalase) activities in hepatic were increased by treatment of rats with the triterpenoids, which suggests that triterpenoids inhibited the reduction of hepatic antioxidative activity caused by high fat diet. Taken together, these results support that euscaphic acid and tormentic acid improve a high fat diet-induced hyperlipidemia via the activation of antioxidative mechanism.

막걸리 첨가 설기떡의 품질 특성 (Quality Characteristics of Sulgidduk Added with Makgeolli)

  • 심은경;김현정;이수진;김미리
    • 한국식생활문화학회지
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    • 제29권6호
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    • pp.605-614
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    • 2014
  • The objective of this study was to investigate the quality characteristics of Baeksulgi (BS) and Sulgidduk added with Makgeolli (MS, BS+ Makgeolli) during storage at $20{\pm}2$ for 3 days. Moisture contents of MS were significantly higher than those of BS during storage. Reducing sugar contents (%) were higher in MS. The pH values were 6.23 and 5.93, for BS and MS, respectively. The pH of MS was lower and thus indicated higher in acidity. The Hunter color L (lightness) and a (redness) values were higher for BS, whereas b (yellowness) value of MS was lower. In the texture analysis, hardness and chewiness of MS were found to be lower, whereas springiness, gumminess, and resilience were higher than those of MS. According to DSC (Differential scanning calorimeter) analysis, enthalpy of MS appeared to be lower than that of BS during storage, which suggests retrogradation of MS was delayed. The total phenol content was higher in MS. The $IC_{50}$ value of DPPH and hydroxyl radical scavenging activity was lower in MS, which means antioxidant activity increased in MS. Results of the preference test showed that appearance, flavor, taste, and overall acceptability of MS scored higher than those of BS. From these results, high quality of MS was derived from Makgeolli addition.

4-nonylphenol의 오존산화 처리반응에 관한 연구 (A Study on Ozonation of 4-nonylphenol)

  • 이철규
    • 한국물환경학회지
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    • 제33권6호
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    • pp.736-743
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    • 2017
  • In this study, 4-nonylphenol (4-NP), an endocrine disrupting chemical, was removed by ozone treatment processes under the various experimental conditions including UV irradiation, $TiO_2$ addition. The ozone flow rate and concentration were maintained at $1.0L{\cdot}min^{-1}$ and $70{\pm}5mg{\cdot}L^{-1}$. The pH, COD and TOC of the samples were obtained every 10 minutes for 60 minutes in laboratory scale batch reactor. We found that the combination of UV irradiation and $TiO_2$ addition for ozonation improves the removal efficiency of COD and TOC in 4-NP aqueous solution. In case of the $O_3/UV/TiO_2$ system, COD and TOC were greatly reduced to 85.3 ~ 94.0% and 89.2 ~ 97.2%, respectively. 4-NP degradation rate constants, $k_{COD}$ and $k_{TOC}$, were calculated based on the COD and TOC values. Significantly, $k_{COD}$ and $k_{TOC}$ were improved in the $O_3/UV/TiO_2$ treatment process compared with single $O_3$ process, because the oxidation and the mineralization of 4-NP were increased by generating of the hydroxyl radical. The $k_{COD}$ and $k_{TOC}$ were obtained to be $5.81{\times}10^{-4}{\sim}10.8{\times}10^{-4}sec^{-1}$ and $11.9{\times}10^{-4}{\sim}19.4{\times}10^{-4}sec^{-1}$ in the $O_3/UV/TiO_2$ process. Activation energy ($E_a$) of ozone oxidation reaction based on $k_{COD}$ and $k_{TOC}$ were increased in order of $O_3/UV/TiO_2$ < $O3/UV$ < $O_3/TiO_2$ < $O_3$ process. It was confirmed that the addition of $TiO_2$ and UV irradiation to the ozone oxidation reaction significantly reduced the $E_a$ value and the degradation of 4-NP.

Protective Effect of Allomyrina dichotoma Larva Extract on tert-butyl Hydroperoxide-induced Oxidative Hepatotoxicity

  • Lee, Kyung-Jin;Lee, Jong-Bin
    • 환경생물
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    • 제27권2호
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    • pp.230-236
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    • 2009
  • An extract of Allomyrina dichotoma larva (ADL), one of the insects used most frequently in traditional Chinese medicine for the treatment of liver diseases such as hepatocirrhosis and hepatofibrosis, was assessed for antioxidant bioactivity in this study. In the current work, we have investigated the protective effects of ADL extracts on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in cultured hepa1c1c7 cells and in the mouse liver. The treatment of the hepa1c1c7 cells with ADL extracts induced a significant reduction of t-BHP-induced oxidative injuries, as determined by cell cytotoxicity, lipid peroxidation (LPO) and reactive oxygen species contents, in a dose-dependent manner. Moreover, ADL extracts evidenced a protective effect against t-BHPinduced oxidative DNA damage, as revealed by the results of the Comet assay in hepa1c1c7 cells. ADL extracts also protected against hydroxyl radical-induced 2-deoxy-d-ribose degradation by ferric ion-nitrilotriacetic acid and $H_2O_2$. In addition, ADL extracts were shown to be able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Our in vivo study revealed that ADL extracts pretreatment applied prior to t-BHP administration significantly prevented an increase in the serum levels of hepatic enzyme markers and reduced LPO in the mouse liver in a dose-dependent manner. Taken together, these results suggest that the protective effects of ADL extracts against t-BHP-induced hepatotoxicity may be attributable, at least in part, to its ability to scavenge free oxygen radicals, and to protect against DNA damage due to oxidative stress.