• Title/Summary/Keyword: Scavenger

검색결과 541건 처리시간 0.033초

A Study on Pumping Effect of Oxygen in Polysilicon Gate Etching

  • Kim, Nam-Hoon;Shin, Sung-Wook;Bin, Shin-Seok;Yu chang-Il kim;Chang, Eui-Goo
    • Transactions on Electrical and Electronic Materials
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    • 제1권2호
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    • pp.1-6
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    • 2000
  • This article presents the experiments and considerations possible about gate etching in polysilicon when oxygen gas is added in chamber, We propose the novel study with optical emission spectroscopy in polysilicon etching. It is shown that added oxygen gases play an important role in enhencement of density in chlorine gases as a scavenger of silicon from SiCl$\_$x/. And a small amount of Si-O bonds are deposited and then the deposited thin film protect silicon dioxyde against reaction chlorine with silicon in SiO$_2$. Consequently, we can improve the selectivity of polysilicon the silicon dioxide, which is clearly explained in this model.

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Nitrite Scavenging Effect by Flavonoids and Its Structure-Effect Relationship

  • Choi, Jae-Sue;Park, Si-Hyang;Choi, Jin-Ho
    • Archives of Pharmacal Research
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    • 제12권1호
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    • pp.26-33
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    • 1989
  • Nineteen flavonoids, five phenolics, two coumarins, maltol and L-ascorbic acid were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds. Many were found to be potent scavenger and the five most potent ones were (+)-catechin, (-)-epicatechin, phloroglucinol, caffeic acid and L-ascorbic acid. The nitrite scavenging effect was higher at pH 1.2 than pH 3.0 and increased when the incubation time was longer. The possible relationship of structures to scavenging effect of the flavonoids tested was discussed.

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디젤로 오염된 지하수의 오존산화처리에 대한 연구 (A study on the Ozone oxidation of Diesel-contaminated Groundwater)

  • 권충일;공성호;김무훈
    • 한국토양환경학회지
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    • 제5권3호
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    • pp.3-15
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    • 2001
  • 본 연구에서는 증류수와 인공지하수, 그리고 지하수를 대상으로 오존의 분해거동(오존의 자가분해, pH의 영향, 용해도)과 오존산화공정에 의한 디젤의 분해(디젤의 분해, TCE와 PCE의 분해, 수산화라디칼 scavenger의 영향, pH의 영향, 오존/과산화수소의 영향)를 조사하였다. 증류수와 지하수내에서 오존의 자가분해는 모두 2차 반응속도식을 보였고, 증류수(반감기 37.5 분)에서보다 지하수(반감기 14.7분)에서 훨씬 빠르게 오존이 분해되었으며, 알칼리성 조건하에서 두 액상에서 모두 오존의 분해는 촉진되었다. 또한 오존산화공정의 사용은 TCE와 PCE, 그리고 디젤에 대해 높은 산화처리속도를 나타내었다. 비록 지하수내에 존재하는 hydroxyl radical scavenger는 디젤의 분해에서 억제제로 작용하였지만, 높은 pH조건과 과산화수소의 첨가는 지하수내에서 디젤을 분해시키는 데 중요한 촉진제로서 작용하였다. 그러므로 오존산화공정은 디젤로 오염된 지하수를 처리하는 데 효과적으로 적용될 것이라 판단된다.

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Physico-mechanical Properties and Formaldehyde/TVOC Emission of Particleboards with Volcanic Pozzolan

  • Kim, Sumin;An, Jae-Yoon;Kim, Jin-A;Kim, Hee-Soo;Kim, Hyun-Joong;Kim, Hak-Gyeom
    • Journal of the Korean Wood Science and Technology
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    • 제35권2호
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    • pp.39-50
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    • 2007
  • The purpose of this study was to investigate the physico-mechanical properties and characteristics on reduction of formaldehyde and total volatile organic compound (TVOC) emission from particleboard (PB) with added volcanic pozzolan. Pozzolan was added as a scavenger at the level of 1, 3, 5, and 10 wt.% of urea formaldehyde (UF) resin for PB manufacture. The moisture content, density, thickness swelling, water absorption and physical properties of PBs were examined. Three-point bending strength and internal bond strength were determined using a universal testing machine. Formaldehyde and TVOC were determined by desiccator and 20L small chamber methods. With increasing pozzolan content the physical and mechanical properties of the PBs were not significantly changed, but formaldehyde and TVOC emissions were decreased. Because pozzolan has a rough and irregular surface with porous form, it can be used as a scavenger for PBs at a content up to 10 wt.% without any detrimental effect on the physical and mechanical properties.

참당귀(Angelica gigas)의 DPPH Radical 소거 활성과 항산화 효과 (DPPH Radical Scavenger Activity and Antioxidant Effects of Cham-Dang-Gui (Angelica gigas))

  • 강순아;한진아;장기효;조여원
    • 한국식품영양과학회지
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    • 제33권7호
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    • pp.1112-1118
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    • 2004
  • 본 연구의 결과를 요약하면 참당귀추출물 1 mg/mL의 농도에서 열수추출물의 free radical소거 효과는 메탄올추출 물보다 높게 나타났으며 농도 의존적으로 DPPH free radical 소거 효과가 상승하는 것을 관찰하였다. 또한 참당귀 투여에 의하여 화학요법으로 발생된 지질과산화물의 생성을 감소시켰으며, 단백질 산화를 유의적으로 억제함으로써 참당귀추출물은 CYP를 투여로 생성된 free radical을 감소시킴으로써 독성을 감소시켜, 혈액학적 빈혈지표가 더 감소되는 것을 막았다고 사료되며, 항산화제로서의 가능성이 있는 한약재로서 활용성이 높을 것으로 사료된다 항산화효소인 SOD 활성은CYP투여에 의하여 활성이 증가하였으며 참당귀추출물의 투여에 의한 효과가 나타나지 않았으나 감소하는 경향을 보였고 catalase 활성은 CYP 투여에 의하여 활성이 증가하였으나 참당귀의 효과는 차이가 없었다. 결론적으로 참당귀추출물은 free radical 소거능을 갖고, 화학요법으로 발생된 지질과산화물의 생성을 낮춰 화학요법에 의한 부작용으로 발생되는 혈액학적 수치의 감소를 막음으로써 항산화제로의 활용성을 기대해본다.

The P275A Polymorphism in the Macrophage Scavenger Receptor 1 Gene and Prostate Cancer Risk: a Meta-Analysis

  • Zhou, Qiao-Xia;Tang, Jian-Qiu;Zhao, Fen;Wei, Fu-Lin;Huang, Ying
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권13호
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    • pp.5407-5413
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    • 2015
  • Background: Published data regarding associations between the P275A polymorphism in the macrophage scavenger receptor 1 (MSR1) gene and prostate cancer (PCa) risk are inconclusive. The aim of this study was to comprehensively evaluate the genetic risk of P275A polymorphism in MSR1 gene for PCa. Materials and Methods: A systematic literature search was carried out in Pubmed, Medline (Ovid), Embase, CBM, CNKI, Weipu, and Wanfang databases, covering all available publications (last search was performed on Apr 27, 2015). Statistical analysis was performed using Revman 5.2 and STATA 10.1 software. Results: A total of 5,017 cases and 4,869 controls in 12 case-control studies were included in this meta-analysis. When all groups were pooled, there was no evidence that the P275A polymorphism had a significant association with PCa under dominant (OR=0.93, 95%CI=0.81-1.06, and p=0.28), co-dominant (homogeneous OR=0.97, 95%CI=0.56-1.68, and p=0.92; heterogeneous OR=0.93, 95%CI=0.74-1.15, and p=0.49), recessive (OR=1.10, 95%CI=0.65-1.87, and p=0.73), over-dominant (OR=0.93, 95%CI=0.75-1.15, and p=0.50), and allelic (OR=0.95, 95%CI=0.77-1.16, and p=0.61) genetic models. For stratified analyses by ethnicity and study design, no significant associations were found in the white race, the yellow race, the black race and mixed ethnicity, and the population-based case-control (PCC) and hospital-based case-control (HCC) studies under all genetic models. Conclusions: Based on our meta-analysis, the P275A polymorphism in the MSR1 gene is unlikely to be a risk factor for PCa.

뇌조직의 활성산소 및 그 제거효소에 미치는 실크 피브로인의 영향 (Effects of Silk Fibroin on Oxygen radicals and Their Scavenger Enzymes in Brain of SD Rats)

  • 최진호;김대익;박수현;김정민;조원기;이광길;여주홍;이용우
    • 생명과학회지
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    • 제10권4호
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    • pp.340-346
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    • 2000
  • This study was designed to investigate the effects of silk fibroin(Mw 500) powder (SFP) on oxygen radicals and the scavenger enzymes in brain membranes of rats. Spragu-Dawley(SD) male rats(160${\pm}$10g) were fed basic diet(control group), and experimental diets(SFP-2.5 and SFP-5.0 groups) added 2.5 and 5.0g/kg BW/day for 6 weeks. Hydroxyl radical($.$OH) levels resulted in a decreases(6.6% and 9.7%, 2.8% and 11.9%, respectively) in brain mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group, but were significantly decreased in these membrances of SFP-5.0 group only. Superoxide radical (O2) levels were a slightly decreased (2.0% and 9.1%, respectively) in brain cytosol of SFP-2.5 and SFP-5.0 groups compared with control group. Lipid peroxide(LPO) levels were significantly decreased (12.9% and 21.9%, 13.2% and 22.5%, respectively) in brain mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were significantly decreased (16.7% and 15.7%, respectively) in brain microsomes of SFP-2.5 and SFP-5.0 group compared with control group, but significantly difference between in brain mitochondria of these two groups could not be obtained. Mn-SOD activities were remarkably increased (11.2% and 24.2%, respectively) in mitochodria of SFP-2.5 and SFP-5.0 groups. CuZn-SOD activities were effectively increased (7.7% and 19.6%, respectively) in brain cytosol of SFP-2.5 and SFP-5.0 groups, but significant difference between control and SFP-2.5 groups could be not obtained. GSHPx activities were considerably increased (5.3% and 11.7%, respectively) in brain cytosol of SFP-2.0 and SFP-5.0 groups compared with control group. There results suggest that anti-aging effect of silk fibroin may play an effective learning and memory role in a attenuating a oxidative stress and increasing a scavenger enzyme activity in brain membranes.

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간장조직의 활성산소 및 그 제거효소에 미치는 실크 피브로인의 영향 (Effect of Silk Fibroin on Oxygen Radicals and Their Scavenger Enzymes in Liver of SD Rats)

  • 최진호;김대익;박수현;김정민;조원기;이광길;여주홍;이용우
    • 생명과학회지
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    • 제10권6호
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    • pp.577-583
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    • 2000
  • This study was designed to investigate the effect of silk fibroin (Mw 500)power (SFP) on oxygen radicals and their scavenger enzymes in liver membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10 g) were fed basic diet (control group), and experimental diets (SFP-2.5 and SFP-5.0 groups) added 2.5 and 5.0 g/kg BW/day for 6 weeks. Hydroxyl radical (.OH) levels resulted in a considerable decreases (5.8% and 8.4%, 3.7% and 11.1%, respectively) in liver motochondria and micorsomes of SFP-2.5 and SFP-5.0 groups compared with control group, and $O_2$radical level was remarkably decreased about 15% and 20% in liver cytosol of SFP-2.5 and SFP-5.0 groups compared with control group. Lipid peroxide (LPO) levels were significantly decreased (8.3% and 18.0%, 13.4% and 18.4%, respectively) in liver mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were remarkably decreased about 11.6% in liver mitochondria of SFP-5.0 group compared with control group. Mn-SOD activities were remarkably in creased (17.6% and 28.8%, respectively) in mitochondria of SFP-2.5 and SFP-5.0 groups, and Cu/Zn-SOD activities were also effectively in creased (about 14.4%) in liver cytosol of SFP-5.0 groups, but significant difference between GSHPx activity in liver cytosol of these two groups could be not obtained. These results suggest that anti-aging effect of silk fibroin may play an effective anti-aging role in a aattenuating a oxidative stress and increasing a scavenger enzyme activity in liver membranes.

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