• 제목/요약/키워드: plasma damage

검색결과 562건 처리시간 0.029초

방사선 손상 Balb/C 마우스 모델에서 누에 체액(Silkworm Hemolymph)의 간조직 보호 효과 (Protective Effect of Silkworm Hemolymph against Gamma Irradiation Induced Damage in the Liver of Mice)

  • 남유리;강정애;노종국;최미희;;장범수;박상현
    • 방사선산업학회지
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    • 제8권1호
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    • pp.7-10
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    • 2014
  • This study was designed to evaluate the protective effect of silkworm hemolymph against ${\gamma}-irradiation$ induced damage in the liver of mice. Female Balb/C mice (6 weeks old) were exposed to ${\gamma}-irradiation$ (6 Gy) and administered orally to silkworm hemolymph ($5ml\;kg^{-1}$ BW) for 7 days post-irradiation. The body weight, spleen index, plasma aspartate transaminase (AST), plasma alanine transaminase (ALT), and liver malondialdehyde (MDA) levels were determined. Compared with irradiated control mice, the activity of plasma AST and the level of MDA were significantly decreased in mice treated silkworm hemolymph. These results show that silkworm hemolymph is found to have a protective effect against ${\gamma}-irradiation$ induced damage in mice.

Metal Antenna 효과로 인한 게이트 산화막에서 정공 포획에 관한 연구 (Study of the Hole Trapping in the Gate Oxide Due to the Metal Antenna Effect)

  • 김병일;신봉조박근형이형규
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.549-552
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    • 1998
  • Recently, the gate oxide damage induced by the plasma processes has been one of the most significant reliability issues as the gate oxide thickness falls below 10 nm. The process-induced damage was studied with the metal antenna test structures. In addition to the electron trapping, the hole trapping in a 10 nm thick gate oxide due to the plasma-induced charging was observed in the NMOS's with a metal antenna. The hole trapping gave rise to the decrease of the transconductance (gm) similarly to the case of the electron trapping, but to the extent much less than the electron trapping. It would be because the electrical stress that the plasma-induced charging forced to the gate oxide for the devices with the hole trapping was much smaller than for those with the electron trapping. This hypothesis was strongly supported by the measured characteristics of the Fowler-Nordheim current in the gate oxide.

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Tryptophan 투여가 Reserpine과 식이 탄수화물 수준이 다른 저단백식이를 섭취한 흰쥐의 혈장 아미노산 농도, 간 Cytochrome P450 함량 및 간세표 미세구조에 미치는 영향 (The Effect of Tryptophan Administration on the Plasma Free Amino Acid Concentration, Liver Microsomal Cytochrome P450 Content and Cellular Structure of Rats Consumed Reserpine and Low Protein Diet with Different Carbohydrate Contents)

  • 신동순
    • Journal of Nutrition and Health
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    • 제29권7호
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    • pp.689-702
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    • 1996
  • The purpose of this experiment was to compare the effects of tryptophan administration on nutritional status of female rats which consumed reserpine and 6% casein diet with different carbohydrate contents(87%, 65%, 44% respective). Final body weight, body weight gain, FER, plasma amino acid concentration and microsomal cytochrome P 450 content in liver were measured and microscopic structure of hepatocytes was observed. In low-protein diet, the higher the carbohydrate content of diet was, the lower the damage was in the rat's liver. Tryptophan administration after dose of reserpine induced more effective recovery from liver damage of rats in high carbohydrate diet group than that in low carbohydrate diet group. In conclusion, the general nutritional assessments such as final body weight and body weight gain provided better estimate of the degree of structural changes in hepatocytes than functional assessment such as plasma amino acid concentration or liver microsomal cytochrome P450.

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플라즈마 분말 용접재의 고온피로특성 (Characteristics of High Temperature Fatigue for welding material by Plasma Transferred Arc Weld)

  • 최성대;정선환;권현규;김기만;김잠규
    • 한국기계가공학회지
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    • 제6권3호
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    • pp.92-97
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    • 2007
  • The overlay welding the automobile where the durability is demanded, it is used in the vessel engine valve, plant valve and pump parts. Cause of damage public opinion one what is thought is the fatigue load due to the opening and shutting operation right time repetition of the engine valve. The damage cause of the engine valve or explanation of destruction mechanism is very difficult. The research which it sees to make clear a overlay welding of Co-alloy by Plasma Transferred Arc Weld Surfacing Process reconsideration fatigue crack initiation and fatigue crack growth mechanism at high temperature.

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초고진공 전자 사이클로트론 공명 화학 기상증착장치의 제작과 수소 플라즈마를 이용한 실리콘 기판 표면 세정화 (Manufacturing of Ultrahigh Vacuum Electron Cyclotron Resonance Chemical Vapor Deposition Reactor and Si Wafer Surface Cleaning by Hydrogen Plasma)

  • 황석희;태흥식;황기웅
    • 전자공학회논문지A
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    • 제31A권4호
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    • pp.63-69
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    • 1994
  • The Ultrahigh Vacuum Electron Cyclotron Resonance Chemical Vapor Deposition(UHV-ECRCVD) system whose base pressure is 1${\times}10^{9}$ torr has been constructed. In-situ cleaning prior to the epitaxial growth was carried out at 56$0^{\circ}C$ by ECR generated uniform hydrogen plasma whose density is $10^{10}/cm{3}$. The natural oxide was effectively removed without damage by applying positive DC bias(+10V) to the substrate. RHEED(Reflection High Energy Electron Diffraction) analysis has been used to confirm the removal of the surgace oxide and the streaky 2$\times$1 reconstruction of the Si surface, and the suppression of the substrate damage is anaylized by X-TEM(cross-sectional Transmission Electron Microscopy). Surface cleaning technique by ECR hydrogen plasma confirmed good quality epitaxial growth at low temperature.

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X-ray and Plasma Process Induced Damages to PLZT Capacitor Characteristics for DRAM Applications

  • Kim, Jiyoung
    • The Korean Journal of Ceramics
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    • 제3권3호
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    • pp.213-217
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    • 1997
  • In this paper, the imparct of X-ray and plasma process-induced-damages to La doped Lead Zirconate Titanate (PLZT, (Pb1-xLa)(Zr0.5Ti0.5)O3) capacitor characteristics have been investigated from the viewpoint of gigabit scale dynamic random access memory (DRAM) applications. Plamsa damage causes asymmetric degradation on hysteresis characteristics of PLZT films. On the other hand, X-ray damage results in a symmetrical reduction of charge storage densities (Qc's) for both polarities. As La concentration increases in the films, the radiation hardness of PLZT films on X-ray and plasma exposures is improved. It is observed that the damaged devices are fully recovered by thermal annealing under oxygen ambient.

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건식식각에 의한 PZT 박막의 플라즈마 손상 및 회복특성 (Characteristics of Plasma Damage and Recover in PZT Films by Dry Etching)

  • 강명구;김경태;김동표;김창일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.375-378
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    • 2002
  • We investigated the reduction of etching damage by additive O$_2$ in etching gas and recovery of etching damage by O$_2$ annealing. The PZT thin films were etched using additive Ar or O$_2$ into Cl$_2$/CF$_4$ gas mixing ratio of 8/2. In order to recover ferroelectric properties of PZT thin films after etching, the etched PZT thin films were annealed at 600 C in O$_2$ atmosphere for 10 min. The remanent polarization is decreased seriously and fatigue is accelerated in the PZT sample etched in Ar/(C1$_2$+CF$_4$) plasma, whereas these characteristics are improved in O$_2$/(Cl$_2$/CF$_4$). From x-ray photoelectron spectroscopy (XPS) analysis, the intensities of Pb-O, Zr-O and Ti-O peaks are changed and the etch byproducts such as metal chloride and metal fluoride are reduced by O$_2$ annealing. From electron probe micro analyzer (EPMA) and auger electron spectroscopy(AES), O$_2$ vacancy is observed after etching. In x-ray diffraction (XRD), the structure damage in the additive O$_2$ into C1$_2$/CF$_4$ is reduced and the improvement of ferroelectric behavioral annealed sample is consistent with the increase of the (100) and (200) PZT peaks.

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$O_2$ plasma 표면 처리 공정에 의한 SOI nano-wire Bio-FET 소자의 전기적 특성 열화 (Degradation of electrical characteristics in SOI nano-wire Bio-FET devices)

  • 오세만;조원주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.356-357
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    • 2008
  • The effects of $O_2$ plasma ashing process for surface treatment of nano-wire Bio-FET were investigated. In order to evaluate the plasma damage introduced by $O_2$ plasma ashing, a back-gate biasing method was developed and the electrical characteristics as a function of $O_2$ plasma power were measured. Serious degradations of electrical characteristics of nano-wire Bio-FET were observed when the plasma power is higher than 50 W. For curing the plasma damages, a forming gas anneal (2 %, $H_2/N_2$) was carried out at $400^{\circ}C$. As a result, the electrical characteristics of nano-wire Bio-FET were considerably recovered.

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THE EFFECT OF GENISTEIN CONCENTRATED POLYSACCHARIDE (GCP) SUPPLEMENTATION ON OXIDATIVE DNA DAMAGE AND PLASMA TOTAL ANTIOXIDANT POTENTIAL IN OLD FEMALE SPRAGUE-DAWLEY RATS.

  • Park, Eunju;Shin, Jang-In;Park, Ok-Jin;Kang, Myung-Hee
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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    • pp.118-119
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    • 2001
  • The anti-cardiovascular effect of estrogen replacement therapy in postmenopausal women is known to be associated with its role as an antioxidant, its ability to protect cells from DNA damage. Genistein concentrated polysaccharide (GCP) is a functional food produced by fermentation of soybean isoflavone extracts with Basidiomycetes, containing rich content of genistein aglycones. The aim of this study was to investigate the effect of GCP on oxidative DNA damage and plasma total antioxidant potential, comparing to the effect of estrogen.(omitted)

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The effect of carrot juice, ${\beta}$-carotene supplementation on lymphocyte DNA damage, erythrocyte antioxidant enzymes and plasma lipid profiles in Korean smoker

  • Lee, Hye-Jin;Park, Yoo-Kyoung;Kang, Myung-Hee
    • Nutrition Research and Practice
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    • 제5권6호
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    • pp.540-547
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    • 2011
  • High consumption of fruits and vegetables has been suggested to provide some protection to smokers who are exposed to an increased risk of numerous cancers and other degenerative diseases. Carrot is the most important source of dietary ${\beta}$-carotene. Therefore, the objective of this study was to investigate whether carrot juice supplementation to smokers can protect against lymphocyte DNA damage and to compare the effect of supplementationof capsules containing purified ${\beta}$-carotene or a placebo (simple lactose). The study was conducted in a randomized and placebo-controlled design. After a depletion period of 14 days, 48 smokers were supplemented with either carrot juice (n = 18), purified ${\beta}$-carotene (n = 16) or placebo (n = 14). Each group was supplemented for 8 weeks with approximately 20.49 mg of ${\beta}$-carotene/day and 1.2 mg of vitamin C/day, as carrot juice (300 ml/day) or purified ${\beta}$-carotene (20.49 mg of ${\beta}$-carotene, 1 capsule/day). Lymphocyte DNA damage was determined using the COMET assay under alkaline conditions and damage was quantified by measuring tail moment (TM), tail length (TL), and% DNA in the tail. Lymphocyte DNA damage was significantly decreased in the carrot juice group in all three measurements. The group that received purified ${\beta}$-carotene also showed a significant decrease in lymphocyte DNA damage in all three measurements. However, no significant changes in DNA damage was observed for the placebo group except TM (P = 0.016). Erythrocyte antioxidant enzyme was not significantly changed after supplementation. Similarly plasma lipid profiles were not different after carrot juice, ${\beta}$-carotene and placebo supplementation. These results suggest that while the placebo group failed to show any protective effect, carrot juice containing beta-carotene or purified ${\beta}$-carotene itself had great antioxidative potential in preventing damage to lymphocyte DNA in smokers.