• Applied Biological Chemistry
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• v.43 no.2
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• pp.110-115
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• 2000

This study was carried out to investigate the effect of extracts from garlic on the formation of nitrosamine, nitrosomorphorine, the nitrite scavenging ability and the antioxidant activity. The extracts from garlic made the nitrite scavenging ability higher at low pH than at high pH. Especially ethanol extracts from garlic resulted in 89.6% of nitrite scavenging ability at pH 1.2. They were also more effective in the electron donating and antioxidant abilities than water extracts in expressing as the reduction of ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$(DPPH) and peroxide value(POV), respectively. Inhibitory effect of nitrosamine formation by ethanol extract from garlic was excellently more than 80% at pH 1.2 and 3.0, but only 29.9% at pH 6.0. This meant that the inhibition of nitrosamine formation is pH dependent.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.405-410
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• 2004

This study was performed to investigate the antioxidative activity of soybean products extracts using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and thiobarbituric acid (TBA) method for application of animal products. All three extracts (natto, soybean paste, soybean milk extract) were found to have an ability to donate hydrogen to DPPH. Especially, natto and soybean paste extract were more effective than that of soybean milk on the antioxidative activities. Natto and soybean paste extract were stronger than butylhydroxy toluene (BHT), butyl hydroxyl anisole (BHA) (5${\times}$10$^{-4}$ M) and ascorbic acid (5.7${\times}$10$^{-3}$ M) previously well known as antioxidants. These extracts also showed a synergistic effect. TBA values of natto (45.8％) and soybean paste extract (45.2％) were stronger than that of soybean milk extract (33.6％). These results suggest that soybean product extracts have antioxidative activities and synergistic effects.

• Journal of the Korean Chemical Society
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• v.19 no.1
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• pp.53-64
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• 1975

The polymerization of methyl methacrylate initiated by cobalt(II) chloride in tetrahydrofuran has been studied. The conversion was increased liearly with polymerization time at initial stage of 6${\sim}$7% conversion and then the rate of polymerization was slightly reduced, and after that the autoacceleration was observed. The rate of polymerization was increased with the concentration of cobalt(Ⅱ) chloride, but at the concentration of cobalt(II) chloride higher than $3.4{\times}10^{-4}$ mole/l the rate of polymerization was decreased. The rate of polymerization was dependent on the 1.38 power of the concentration of methyl methacrylate. The effect of the radical inhibitor DPPH was observed and the inhibition time was increased with the concentration of DPPH. The apparent overall activation energy was calculated to be 13.2 kcal/mole. In the copolymerization of methyl methacrylate ($M_1$) and styrene ($M_2$), the monomer reactivity ratio was found to be $r_1$ = 2.35, $r_2$ = 0.78. From the above results. the initiation mechanism of polymerization was discussed and it was considered that the polymerization proceeds mainly via diradical mechaism.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.109-118
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• 1991

The present study was conducted to assess the possible contribution of arachidonic acid to generation of reactive oxygen metabolites and myocardial damage in ischemic-reperfused heart. Langendorff preparations of isolated rat heart were made ischemic by hypoperfusion (0.5 ml/min) for 45 min, and then followed by normal oxygenated reperfusion (7 ml/min). The generation of superoxide anion was estimated by measuring the SOD-inhibitable ferricytochrome C reduction. The myocardial cellular damage was observed by measuring LDH released into the coronary effluent. Oxygenated reperfusion following a period of ischemia produced superoxide anion, which was inhibited by both indomethacin (60 nmole/ml) and ibuprofen $(30\;{\mu}g/ml)$. Sodium arachidonate $(10^{-7}-10^{-2}{\mu}g/ml)$ administered during the period of oxygenated reperfusion stimulated superoxide anion production dose-dependently. The rate of arachidonate-induced superoxide generation was markedly inhibited by indomethacin, a cyclooxygenase inhibitor; nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, and by eicosatetraynoic acid (ETYA), a substrate inhibitor of arachidonic acid metabolism. The release of LDH was increased by Na arachidonate and was inhibited by superoxide dismutase. The release of LDH induced by arachidonic acid was also inhibited by indomethacin, NDGA and ETYA. In conclusion, the present result suggests that arachidonic acid metabolism is involved in the production of reactive oxygen metabolite and plays a contributory role in the genesis of reperfusion injuy of myocardium.

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.149-156
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• 1993

Monoclonal antibodies (Mabs) were produced against crude scolex extract of T solium metacestodes, and applied to ELISA-inhibition test for improving the specificity of serodiagnosis of human cysticercosis. Four hybridomas secreting species-specific anti- cysticercal Mabs (Cya-1, Cya-7, Cya-28 and Cya-31) were selected. Each Mab reacted on antigenic components of 25.5 kDa (Cya-1), 28 kDa (rcya-7), 87.5 kDa (Cya-281), and 12.5 kDa (Cya-31). IFA showed that Cya-1 was located at the calcium corpuscles, and Cya-7 at the loose connective tissue of T soLium metacestode scolex. Cya-28 and Cya-31 reacted on the tegument of the scolex. By conventional ELISA, 23 out of 28 (82.1%) cysticercosis patients were found serologically positive, but 1 out of 9 (11.1%) sparganosls cases and 6 out of 31 (19.4%) paragonlmiasis cases showed false positives. By ELISA-Inhibition test using species-specific anti-cysticercal Mab Cya-7, 19 out of 28 (67.9%) cystlcercosis cases were found serologically positive, but there were no false positives In other parasitic infections.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.187-194
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• 1995

The present study aims to observe changing patterns of serum antibody to hleumuvstis calinii in normal rats of different ages and in immunosuppressed rats. The serum IgG antibody was observed by immunoblotting with crude antigen of f carinii which were purified from the lungs of infected rats. The crude antigens separated in SDS-PAGE resolved more than 20 protein bands from 20 to 200 kDa. Of them,40-45, 50-55, 116 and 200 kDa bands were major antigens of R cori.nii. Most of the normal rats of up to 4 weeks had the antibodies reacting the 4 bands, but none of 8-week-old rats revealed the specific antibody. After the rats grew for 40 weeks, all were found to have the antibody in their serum. Same pattern of serum antibody level by age was found in ELISA. When immunosuppressed rats became heavily infected, the antibody in their serum decreased distinctively. The present results suggest that antibodies in normal newborn rats are transferred from their mother and lowered up to 8 weeks. Thereafter, the levels of the antibodies begin to increase by natural exposure to R cnrinii. It was also confirmed that the intensity of P cnrinii infection is inversely related with levels of serum antibodies.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.731-738
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• 1996

노심 손상이 일어나는 중대사고 발생시 고온의 노심 용융물이 윈자로 용기를 파손시키며 캐비티 내로 유출되는 경우, 노심 용융물과 냉각재의 폭발적 반응을 억제하고 잔열제거를 위한 효과적인 냉각수 주입 방법을 규명하는 실험을 수행하였다. 냉각수 주입 방법은 파이프 관을 이용한 단순 fouling 방식과 노즐을 이용한 Spray 방식, 그리고 반응용기의 옆면으로 냉각수를 주입하는 세 가지 방식을 채택하였다. 동일한 실험 조건에서 각각의 주입 방법에 따른 반응 형태 및 냉각 정도를 알아보는 실험을 수행하였다. 본 논문에서는 일차적으로 노심 용융물의 모사체로 사용한 주석 용융물에 Pouring 방식과 Spray 방식으로 냉각수를 주입한 경우의 실험 결과를 정리하였으며, 분석 결과 Spray 방식으로 냉각수를 주입한 경우에 폭발적 반응이 일어나지 않고 냉각됨을 알 수 있었다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.159-159
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• 1993

개의 관상동맥평활근세포를 이용하여 $K^{＋}$channel openers인 cromakalim과 pinacidil의 이완반응을 관찰하고, 이러한 이완반응의 세포내 기전에 대하여 검토하고자 하였다. Collagenase로 소화시켜 구한 평활근 세포들은 frypan blue 배출 검사 및 전자현미경학적으로 검사시 건전하고 생존해 있었다. 분산평활근세포들은 phenylephrine(PE)의 용량에 의존하여 수축하였고, EC$_{50}$는 2.3$\times$$10^{－12}$M이었다. PE에 의한 수축반응은 $K^{＋}$channel openers인 cromakalim 및 pinacidil의 용량에 의존하여 억제되었고 이때의 EC$_{50}$치는 각각 1,2$\times$$10^{－10}$M 및 6.B$\times$$10^{－10}$M이었다. 비교실험으로서 근절편의 장력을 측정하여 수축을 검정한 실험에서는 cromakalim의 이완반응의 ECEC$_{50}$치는 1.94$\times$$10^{－7}$ M로 근세포실험에 비하여 감수성이 훨씬 약하였다.훨씬 약하였다.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.10
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• pp.1738-1744
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• 2001

본연구의 목적은 반응성 염료를 이용한 텐셀섬유의 피브릴화 조절 효과를 표면 형태, 감량율, 역학적 성질 및 태의 변화의 측면에서 고찰하는데 있다. 반응성 염료에 의한 가교는 섬유의 비결정 영역의 구조를 변화시켜 피브릴화를 억제하였으며 또한 효소의 작용에 영향을 주어 감량율을 감소시켰다. 반응성 염료에 의한 가교는 역학적 성질 중 특히 전단강성, 압축에너지, 압축레질리언스를 증가시켰다. 염색후 효소처리한 시료는 다른 시료보다 numeri와 fukurami 값이 높아 더 나은 종합태를 보였다. 공정순서에 따라 약간씩 차이가 있는 촉감을 나타냈다.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.367-369
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• 2011

본 연구에서는 글리세롤과 우레아를 이용하여 글리세롤카보네이트를 합성하는 반응을 진행하였다. ZnO와 Zn-Al 이원계 금속 산화물 촉매를 제조하고, 제조되어진 촉매를 사용하여 글리세롤의 전환율과 글리세롤카보네이트의 수율을 확인하였고, Al의 첨가에 따른 촉매 특성의 분석과 글리세롤카보네이트 합성반응에서의 역할에 대해 확인하였다. 글리세롤카보네이트 합성 반응에서 ZnO를 단독으로 촉매를 사용한 경우보다 Zn-Al 혼합 산화물을 촉매로 사용하여 반응하였을 때, 부반응이 억제되어 전환율 및 수율이 증가함을 확인하였다.