• Title/Summary/Keyword: damage fraction

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X-ray diffraction analysis of the effect of ball milling time on crystallinity of milled polyacrylonitrile-based carbon fiber

  • Lee, Sang-Hye;Kang, Dong-Su;Lee, Sang-Min;Roh, Jae-Seung
    • Carbon letters
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    • v.26
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    • pp.11-17
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    • 2018
  • Milled carbon fiber (mCF) was prepared by a ball milling process, and X-ray diffraction (XRD) diffractograms were obtained by a $2{\theta}$ continuous scanning analysis to study mCF crystallinity as a function of milling time. The raw material for the mCF was polyacrylonitrile-based carbon fiber (T700). As the milling time increased, the mean particle size of the mCF consistently decreased, reaching $1.826{\mu}m$ at a milling time of 18 h. The XRD analysis showed that, as the milling time increased, the fraction of the crystalline carbon decreased, while the fraction of the amorphous carbon increased. The (002) peak became asymmetric before and after milling as the left side of the peak showed an increasingly gentle slope. For analysis, the asymmetric (002) peak was deconvoluted into two peaks, less-developed crystalline carbon (LDCC) and more-developed crystalline carbon. In both peaks, Lc decreased and $d_{002}$ increased, but no significant change was observed after 6 h of milling time. In addition, the fraction of LDCC increased. As the milling continued, the mCF became more amorphous, possibly due to damage to the crystal lattices by the milling.

Inhibitory Effects of Bovine Serum Albumin on Cytotoxicity and Mutagenicity of 6-Sulfooxymethylbenzo[a]pyrene

  • Cho, Young-Sik;Cho, Kyung-Joo;Chung, An-Sik
    • Toxicological Research
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    • v.16 no.3
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    • pp.221-227
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    • 2000
  • A 6-sulfooxymethylbenzo[a]pyrene (SMBP), the ultimate metabolite of methyl-substituted benzo[a]pyrene (BP), has been found to be carcinogenic in mice. These properties may be attributable to its strong reactivity with cellular macromolecules such as DNA. However, serum and its major constituent albumin attenuated significantly the cytotoxicity and mutagenicity of 5MBP in bacterial and mammalian cell systems. This inhibitory activity of serum against 5MBP-induced cytotoxicity and mutagenicity in Chinese hamster V79 cells appears to be caused by the reduced macromolecular adducts such as DNA and proteins, but serum failed to reduce 5MBP binding to naked calf thymus DNA. A number of proteins in the serum could act as nucleophiles that are able to intercept reactive chemicals through covalent binding. Albumin present in the plasma seems to be one of major components responsible for direct binding with 5MBp, thereby reducing its reactivity to genetic materials. We here determined which fraction is preferential for 5MBP binding through fractionation of 5MBP-treated serum with ammonium sulfate. The albumin-containing fraction had slightly more affinity for 5MBP than the immunoglobulin-containing fraction. Our results indicate that the covalent modification of plasma proteins may reduce 5MBP-induced damage.

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Antioxidant Activity of Rosa rugosa (해당화의 항산화 효과)

  • 서영완;이희정;안종웅;이범종;문성기
    • KSBB Journal
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    • v.19 no.1
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    • pp.67-71
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    • 2004
  • An antioxidant activity of Rosa rugosa extract and its solvent-partitioned fractions was determined not only by measuring lipid peroxide produced when a mouse liver homogenate was exposed to the air at 37$^{\circ}C$, using thiobarbituric acid (TBA) but also by evaluating the free radical scavenging effect against DPPH radical, authentic peroxynitrite, and 3-morpholinsydnonimine (SIN-1). All its partitioned fractions including crude extract showed potent scavenging effect against DPPH radical, peroxynitrite, and lipid peroxidation. n-BuOH fraction, in particular, was found to be the most effective in DPPH radical scavenging ability as well as inhibition against lipid peroxidation. The 15% aqueous MeOH fraction also showed a strong potency which was slightly lower than n-BuOH fraction. Based on these results, we suggest that Rosa rugosa could be useful for preventing an oxidative damage.

Effect of various fractions of Bacopa monnieri Linn. aerial parts on ethanol-induced hepatotoxicity in rats

  • Ghosh, Tirtha;Maity, Tapan Kumar;Dash, Deepak Kumar;Bose, Anindya
    • Advances in Traditional Medicine
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    • v.7 no.3
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    • pp.297-303
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    • 2007
  • The ethyl acetate fraction (EAF) and n-butanol fraction (NBF) of ethanolic extract of Bacopa monnieri aerial parts were screened for hepatoprotective activity and in vivo antioxidant activity on ethanol-induced hepatotoxic rats. Ethyl acetate fraction was found to be more potent even though both the fractions were endowed with significant hepatoprotective activity. EAF and NBF were investigated for hepatoprotective activity in albino rats at 300 mg/kg, p.o. dose and compared with standard drug Silymarin (25 mg/kg, p.o.). Results show that both the fractions were effective in blunting ethanol-induced enhanced activities of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, alkaline phosphatase, level of serum bilirubin (both total and direct), liver weight loss and was also effective in reducing ethanol-induced lipid peroxidation both in vitro and in vivo. Furthermore, the fractions could also enhance ethanol-induced suppressed activities of superoxide dismutase, catalase and decreased level of reduced glutathione. Results of hepatocellular damage caused by ethanol and its recovery by EAF and NBF, suggest that they might be considered as a potential source of natural hepatoprotective agents, which could be related to the free radical scavenging properties of saponins present in high concentration in the fractions.

Free radical scavenging activity and protective effect from cellular oxidative stress of active compound from eggplant (Solanum melongena L.) (가지(Solanum melongena L.) 활성물질의 라디칼 소거능과 산화적 스트레스에 대한 세포 보호 효과)

  • Kim, Hyun-Young;Cho, Yun-Ju;Yamabe, Noriko;Cho, Eun-Ju
    • Korean Journal of Agricultural Science
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    • v.38 no.4
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    • pp.625-629
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    • 2011
  • To investigate the protective effect of eggplant (Solanum melongena L.) and its active compound, delphinidin, we used in vitro and cellular system. The active fraction from eggplant, BuOH fraction, showed protective effect from hydrogen peroxide-induced oxidative stress in WI-38 fibroblast cells. It suggests that eggplant would have the protective activity from radical-induced oxidative damage and its BuOH fraction would play the crucial role with antioxidative activity. In addition, delphinidin, the active compound from eggplant, exerted the strong 1,1-diphenyl-2-picrylhydrazyl scavenging effect with $IC_{50}$ value of 6.59 ${\mu}g/mL$. Furthermore, the cellular oxidative stress was induced by 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in LLC-$PK_1$ cells, while treatment of delphinidin atteunated AAPH-induced oxidative stress as dose-dependent manner. The present study suggests the antioxidative activity of eggplant and delphinidin against free radical-induced oxidative stress.

Clinical Study of Ventricular Function Following Open Heart Surgery by Radionuclide Angiocardiogram - left ventricular ejection fraction by ECG gated blood pool scan - (방사성 동위원소를 이용한 개심술 전후의 심실기능 변화에 관한 연구: ECG gated blood pool scan을 이용한 ejection fraction 검사)

  • Lee, Jeong-Cheol;Kim, Gyu-Tae
    • Journal of Chest Surgery
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    • v.19 no.1
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    • pp.25-34
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    • 1986
  • Recently, radionuclide angiocardiogram is one of the most common procedure for assessment of ventricular performance due to its distinctive advantages such as safety, accuracy, and ease of repeated studies. Also, measurement and comparison between pre and postoperative left ventricular ejection fraction [LVEF] are meaningful for assessing the severity of myocardial damage which occurred during open heart surgery and the status of myocardial recovery. We obtained pre and post operative LVEF using radionuclide angiocardiogram on 30 patients composed of atrial septal defect, ventricular septal defect, cyanotic congenital heart disease, and valvular heart disease who undergone the open heart surgery from March to august 1984. The study revealed that ventricular septal defect and mitral valvular heart disease showed 8.1% and 6.2% decreases of postoperative LVEF, respectively. But, there are little increases of postoperative LVEF in the atrial septal defect and cyanotic congenital heart disease. In ventricular septal defect, each group of Qp/Qs over 2.0 and systolic pulmonary artery pressure over 50mmHg showed significant 17% and 14.7% decreases of postoperative LVEF, respectively. Considering the duration of the aortic cross clamping times and closing methods of VSD, each group of duration over 30 min. and of patch closure showed 13.9% and 14.2% decreases of LVEF between pre and postoperative status respectively which was significant finding statistically.

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Anti-Oxidant and Hepato-protective Activities of the Stems of Acanthopanax senticosus

  • Son , Dong-Wook;Ryu , Ji-Young;Kang , Jun-Gil;Lee, Sang-Yun;Kim, Hyun-Su;Lee, Sang-Hyun;Hoon, Jung-Sang;Lee, Yeon-Sil;Shin, Kuk-Hyun
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.191.1-191.1
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    • 2003
  • The anti-oxidant activities of Acanthopanax senticosus stems were investigated. The n-BuOH fraction of A. senticosus stems exhibited a significant decrease in serum transaminase activities elevated by hepatic damage induced by CCl$_4$-intoxication in rats. The n-BuOH fraction inhibited the sGPT activities by 65.79%. The n-BuOH fraction showed the increase in the anti-oxidant enzymes such as hepatic cytoso1ic superoxide dismutase, catalase and glutathione peroxidase activities by 30.31, 19.82 and 155%, respectively, in CCl$_4$-intoxicated rats. These results suggest that the stems of A. senticosus possess not only the hepatoprotective, but also the anti-oxidant activities in rats.

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PROTECTION OF DNA BY SCUTELLARlA BAICALENSIS IN HL-60 CELLS EXPOSED TO $\gamma$-RAYS; ANALYSED BY MICRONUCLEI FORMATION AND SINGLE CELL GELL ELECTROPHORESIS

  • Heon Oh;Park, Hae-Ran;Ham, Yeon-Ho;Kim, Sung-Ho;Jo, Sung-Kee
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.107-107
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    • 2001
  • In the present study, the protective effect of Scutellaria baicalensis against DNA damage in HL-60 cells exposed to $^{60}$ Co ${\gamma}$-rays was evaluated using micronuclei formation and alkaline single cell gel electrophoresis (SCGE, comet assay). The frequency of micronuclei was decreased in groups treated with water extract (P<0.01), polysaccaride fraction (P<0.01) and methanol fraction (P<0.01) before/after exposure to 200 cGy of ${\gamma}$-rays.(omitted)

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The Radioprotective Effect of Panax ginseng of the Hair Medullary Cell in Irradiated Mice (방사선 피폭 마우스의 털 수질세포에 대한 인삼의 방사선 방호효과)

  • 김성호;한동운
    • Journal of Ginseng Research
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    • v.20 no.2
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    • pp.149-153
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    • 1996
  • Studies were Performed to determine whether the water fraction of Panax ginseng Protected radiation damage to hair medullar cells of N:GP(s) mice after in vivo irradiation with $^{60}Co{\;}{\gamma}-rays$. The hair follicles in the middle of the growth cycle were analysed 3 days after 3 Gy irradiation for the changes in the number of cells in the forming medulla of the hair in the region just above the germinal matrix of the growing (anagen) hair follicle. The radioprotective effect of ginseng was compared with the irradiation control. The medullar cell count per unit length ($100{\;}\mu\textrm{m}$) of hair follicle was higher in the pretreated-groups of ginseng, both oral (2 mg/ml of drinking water, p<0.05) and intraperitoneal (0.3 mg/head, p<0.001) treatments, than the irradiation control. These data suggested that the water fraction of Panax ginseng may reduce cell damages on the body surface caused by ${\gamma}-rays$.

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Effect of Antioxidant Activity and Induction of DNA Damage on Human Gastric Cancer Cell by Rubus coreanus Miquel (복분자 추출물의 항산화활성 및 인간 위암 세포주에 대한 유전적 손상 유도)

  • Jeon, Sang-Kyung;Lee, Ji-Won;Lee, In-Seon
    • Journal of Life Science
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    • v.17 no.12
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    • pp.1723-1728
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    • 2007
  • Rubus coreanus Miquel (RCM), a type of red raspberry, grows wild in Korea and China and its unripe fruit is used as a folk medicine for the treatment of impotence and as a diuretic. RCM was extracted with methanol and then further fractionated it into for different types. In this study, we investigated the antioxidant activity of a RCM extract (ext.) and its fraction (fr.). DPPH free radical scavenging activity assay, total polyphenols contents, total flavonoids contents assay were used to analyze antioxidant activity. The DPPH free radical scavenging activity $(RC_{50}:1.67{\mu}g/ml)$ and total polyphenols contents $(546.25{\mu}g/mg)$ were higher in butanol fraction than in other fr. And total flavonoids contents was higher in ethylacetate fr. $(141.78{\mu}g/mg)$. We applied comet assay to measure the DNA damage in the individual cells and exposed time course at $IC_{50}$. Comet assay is a rapid and sensitive fluorescent microscopic method to examine DNA damage and repair at individual cell level. The butanol fro from RCM significantly induced 54.12%, 57.95% of DNA damage after treated RCM for 8 hr. In conclus