• 대한화학회지
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• 제14권3호
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• pp.237-242
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• 1970

Effect of Added 1-hexene on the yield of hydrogen produced from Co-60 gamma radiolysis of methanol was investigated at room temperature. The results indicated that the yield of hydrogen decreased rapidly with increasing 1-hexene concentrations. Effect of added methyl borate on the radiolysis of methanol was also studied in the presence of oxygen. The results revealved that methyl borate acted as a less effective scavenger than oxygen towards the precursors of the radiolysis products. Experimental data previously obtained on the systems with oxygen added were treated more quantitatively to re-examine mechanism of the radiolysis of methanol in detail.

• 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.

• 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.

• 생명과학회지
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• 제10권4호
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• pp.347-353
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• 2000

This study was designed to investigate the effects of silkworm (Bombyx mori L.) powder (SWP) on oxygen radicals and their scavenger enzymes in liver membranes of rats. Sprague-Dawley(SD) male rats(160$\pm$10g) were fed basic diet (control group), and experimental diets(SWP-200 and SWP-400 groups) added 200 and 400 mg/kg BW/day for 6 weeks. Hydroxyl radical (.OH) levels resulted in a consistent decreases (4.0% and 7.2%, 5.0% and 14.1%, respectively) in liver mitochondria and microsomes of SWP-200 SWP-400 groups compared with control group, and O2 radical level was significantly decreased about 12% in liver cytosol of SWP-400 group compared with control group. Lipid peroxide(LPO) levels were significantly decreased (14.4% and 9.1%, respectively) in liver mitochondria and microsomes of SWP-400 group only compared with control group. Oxidized protein (OP) levels were remarkably decreased about 12.7% and 16.3% in liver microsomes only of SWP-200 and SWP-400 groups, but significant difference between liver mitochondria could not obtained. Mn-SOD activities were remarkably increased (15.8% and 25.2%, respectively) in mitochondria of SWP-200 and SWP-400 groups, but significant difference between Cu, Zn-SOD activities in these group could be not obtained. GSHPx activity was significantly increased in liver cytosol of SWP-400 group compared with control group. These results suggest that silkworm powder may play an effective role in a attenuating a oxidative stress and increasing a scavenger enzyme activity in liver membranes.

• 한국식품위생안전성학회지
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• 제14권2호
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• pp.179-185
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• 1999

Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of the subfractions of butanol fraction has been evaluated by analyzing oxygen free radical scavenging enzyme activities and histopathological examinations. In BS-5 subfraction treated group, the activity of superoxide dismutase has been significantly increased as compared with that of CCl4, treated rats. Antioxidant activity has been evaluated by the examination of the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical. BS-5 subfraction has shown strong antioxidant activities. The histopathological examination showed that the treatment of BS-5 subfraction has relieved the ballooning degeneration of hepatocytes which had been generated by CCl4. It appears that the protective effect of BS-5 subfraction would be mediated of the attenuation of lipid peroxidation by acting as a free radical scavenger, which were based on the increase of superoxide dismutase activity.

• 한국잠사곤충학회지
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• 제41권3호
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• pp.216-221
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• 1999

This study was designed to investigate the effects of silk fibroin powder on oxygen radicals and their scavenger enzymes in serum of rats. Sprague-Dawley(SD) male rats (160${\pm}$10 g) were fed experimental diets (SFP-2.5 and SFP-5.0 groups)added 2.5 and 5.0 g/kg BW/day for 6 weeks. Triglyceride levels were remarkably inhibited (15∼25%) in SFP-2.5 and SFP-5.0 groups compared with control group. Hydroxyl radical ($.$OH) formations resulted in a marked decrease (15%∼25%) compared with control group, while superoxide radical and hydrogen peroxide formations resulted in a significant decrease (6∼12% and 10%). Lipid peroxide and oxidized protein (>C=O group) productions resulted in a significant decrease (6∼12% and 6%) compared with control group. Superoxide dismutase (SOD) and catalase (CAT) activities were remarkably increased (35∼55% and 40∼50%), but glutathione peroxidase (GSHPX) activities were significantly increased (13%) compared with control group. These results suggest that anti-aging effect of silk fibroin powder (SFP) may play a pivotal role in attenuating a various age-related changes.

• 한국식품과학회지
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• 제12권4호
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• pp.229-234
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• 1980

라면을 실험실(實驗室) 규모(規模)로 제조(製造)하여 일부(一部)는 Cellophane-PE필름(40 micron)에 (Control), 일부(一部)는 가스 불투과성(不透過性) Nylon-PVC-PE필름(40 micorn)에 탈산소제(脫酸素劑)(Fe-분말형(粉末型)) 및 150 ml의 공기와 함께, 또다른 일부(一部)는 같은 필름에 진공포제(眞空包製)(74 mmHg)하였다. 이상(以上)의 Control 및 시료(試料)를 항온기(恒溫器)$(45.0{\pm}0.5^{\circ}C)$에서 장기저장(長期貯藏)하여 탈산소제(脫酸素劑)의 산소제거능력(酸素除去能力), 각 시료(試料)의 유지성분(油脂成分)의 과산화물(過酸化物)값과 TBA값의 변화(變化)를 조사(調査)하였다. 그 결과(結果)는 다음과 같다. 1. 탈산소제(脫酸素劑)를 사용한 시료(試料)의 경우, 저장(貯藏) 48시간(時間) 후의 포제내(包製內)의 잔존산소량(殘存酸素量)은 포장직후(包裝直後)의 21%에서 0. 5%로 감소하였다. 2. Control, 탈산소제(脫酸素劑)를 사용한 시료(試料) 및 진공포제(眞空包製)한 시료(試料)들의 저장(貯藏) 45일(日) 후의 과산화물값은 $12.4{\pm}0.4$, $5.7{\pm}0.2$와 $6.8{\pm}0.1\;meq/㎏$이었으며, TBA값은 $1.31{\pm}0.04$, $0.60{\pm}0.04$와$0.72{\pm}0.07$로써 Control과 기타 시료(試料)들의 과산화물값 및 TBA값에는 큰 차이가 있었다. 특히 탈산소제(脫酸素劑)를 사용한 시료(試料)의 과산화물값과 TBA값은 Control은 물론(勿論) 진공포제(眞空包製)한 시료(試料)의 경우보다 낮았으며, 따라서 산패(酸敗)에 대해서 더 큰 안전성(安全性)을 갖았었다고 볼 수 있다.

• 대한의생명과학회지
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• 제15권2호
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• pp.153-160
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• 2009

Photodynamic therapy(PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species(ROS), which selectively accumulate in target cells. The aim of present work is to investigate the photodynamic therapy mechanism of 9-HpbD-a-mediated PDT in HeLa cell lines. We studied the general reactive oxygen species(G-ROS) activation after 9-HpbD-a PDT using fluorescence stain with $H_2DCF-DA$. G-ROS activation observed after 9-HpbD-a PDT and higher activation condition was 1 hour after PDT at 0.5 ${\mu}g/ml$ 9-HpbD-a concentration. Sodium azide and reduced glutathione(the singlet oxygen quencher) could protect HeLa cells from cell death induced by 9-HpbD-a PDT. But D-mannitol(the hydroxyl radical scavenger) could not protect cell death. Singlet oxygen played a decisive role in 9-HpbD-a PDT induced HeLa cell death. Type II reaction was the main type of ROS formation at 9-HpbD-a PDT.

• Journal of Life Science
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• 제9권2호
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• pp.1-4
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• 1999

Nonactin, as a radical-producing antibiotic, was isolated from the cultural broth of the strain JM-4151. This strain was identified as Streptomyces viridochromogenes and designated S. viridochromogenes JM-4151. The antibacterial activity of nonactin against Bacillus subtilis was antagonized by the activity opf quercetin, an oxygen radical scavenger. This result suggests that oxygen radical formation might be the cause for the antibacterial activity of nonactin.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.59-63
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• 2020

PEMFC 고분자막의 내구성을 향상시키기 위해서 Radical 제거제가 사용되고 있다. 본 연구에서는 라디칼 제거제로서 해조류에서 추출한 후코이단이 고분자막의 전기화학적 열화를 방지하는지 Fenton 실험과 가속내구 평가방법(OCV Holding) 실험을 통해 검토하였다. 후코이단은 항산화 효과가 있어 과산화수소와 산소 라디칼로부터 고분자막을 보호해 열화속도를 1/10로 감소시켰다. 후코이단이 라디칼 제거제로 사용되는 MnO₂보다 효과적임을 보였다. PEMFC셀에서 OCV Holding 실험한 결과, 후코이단이 고분자막의 수소투과도를 12% 감소시켰고, 성능은 라디칼 제거제가 없을 때 보다 29.1% 감소시켜 PEMFC 셀에서도 라디칼 제거제의 역할을 함을 확인하였다. 그리고 후코이단을 Anode쪽보다 Cathode 쪽 전극 이오노머에 넣은 것이 더 효과적임을 확인하였다.