• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2004.07a
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• pp.45-45
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• 2004

대사작용의 개선, 정장작용과 유독 물질의 제거, 혈압과 콜레스테롤치의 정상화, 항균 및 항암효과 등 다양한 생리작용을 갖는 것으로 알려진 해조류의 기능성 규명을 위한 연구의 일환으로 총 6종(진두발, 갈래곰보 꼬시래기, 돌가사리, 고장초 톳)의 해조류의 에탄을 추출물에 대한 항산화 효과를 실험하였다. 해조류의 환원력은 시료의 첨가농도에 비례하는 경향이었으며, SOD 유사활성은 고장초의 경우 가장 높은 활성을 나타내었는데 첨가농도 500 $\mu\textrm{g}$/$m\ell$와 1000 $\mu\textrm{g}$/$m\ell$에서 각각 35.43%와 56.71%의 활성을 나타내었다. (중략)

• Proceedings of the KOR-KST Conference
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• 2003.02a
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• pp.97-116
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• 2003

본 연구에서는, 기존의 악세스빌리티지표가 다양한 효과를 고려하지 못한다는 점에 착안하여, 새로운 악세스빌리티지표를 개발하였다. 노드의 중심성을 나타내는 중심도함수에 근거해, 네트워크 악세스빌리티지표(Netword Accessibility Index)와 철도이용자의 효용최적화의 관점으로부터 유틸리티 악세스빌리지표(Utility Accessibility Index)를 제안하였다. 그리고, 본 연구에서 제안한 지표가 종래의 지표보다 철도건설에 따른 편익치를 보다 정확하게 나타내는지를, 서울시지하철5호선과 오사카JR동서선의 개업효과를 계측함으로써 검증하였다. JR동서선의 경우, 중심지까지의 기존노선이 기설되어 있어 소요시간 단축효과보다 수송력증강과 철도네트워크의 확충에 의한 효과가 보다 크게 반영되었다. 또한, 위에서 산출한 편익치를 환수하기위한 기초데이타로 활용해, 고정자산세와 토지양도 소득세를 적용해 환원액을 산출하였다. 그리고, 이렇게 구한 환원액을 특정재원화시켜, 지하철5호선과 JR동서선의 사업주체에 보조해, 사업자의 채산성에 어떠한 영향을 미치는지, 신선건설비를 부담하는 해당 지자체의 비용부담을 어느정도 경감시킬 수 있는지를 정량적으로 밝혔다.

• Journal of the Korean Professional Engineers Association
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• v.10 no.1
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• pp.15-18
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• 1977

국내에서 현재 생산중인 산화방간 4종을 비롯한 기타 여러 지역에 부존된 산화망간 시료와 수입한 산화망간 7종류 중에서 이산화망간의 건전지에 대한 활성도를 각각 실험해 보았다. 실험 방법은 강알카리성에서 Hydrazine Sulfate의 환원력을 이용하여 Activity Index Value를 구하였다. 그 결과 이산화 망간으로 직접 건전지를 만들어 방전시킨 방전곡선과 또한 $\alpha$.$\beta$.${\gamma}$.등의 결정구조가 활성도에 미치는 영향과의 관계가 잘 일치함을 알 수 있고 지금까지는 건전지용 이산화망간의 활성도를 시험하기 위하여 직접 건전지를 제작하여 장시간의 방전시험을 하였던 것을 본 실험에 따르면 Activity Index Value만 측정하여 비교 검토만 하므로서 간단히 그리고 빠른시간 내에 이산화망간의 건전지에 대한 활성도를 확인 결정할 수 있다.

• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.280-286
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• 2013

This study was performed to investigate the effect of types of microorganisms on the antioxidant activity of soybean yogurt by a single or mixed culture of Bacillus subtilis and Lactobacillus plantarum isolated from chunggukjang and kimchi. The fermented soybean milk by Bacillus subtilis exhibited the highest values of total polyphenol, DPPH radical scavenging activity, reducing power and nitrite scavenging activity compared to those of Lactobacillus plantarum or mixed culture of Bacillus subtilis/Lactobacillus plantarum. As the amount of tomato extract was added to the soybean milk, various antioxidant parameters, such as total polyphenol, DPPH radical scavenging activity, reducing power and nitrite scavenging activity, were linearly increased.

• Journal of Life Science
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• v.21 no.9
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• pp.1266-1273
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• 2011

Saponin is a main component of ginseng widely known as an oriental traditional medicinal ingredient. A variety of biological effects of saponin has been reported, but its action related to skin regeneration has remained unclear so far. In this study, the effect of saponin on matrix metalloproteinase as well as its antioxidant effect in cell free system was examined in human dermal fibroblasts. First of all, as a result of investigating the effect of saponin on cell viability using MTT assay, it was shown to increase cell viability below 10 ${\mu}g$/ml, but it also showed cytotoxicity above 25 ${\mu}g$/ml. The antioxidant effect of saponin was exerted by inhibition of $H_2O_2$ in addition to reducing power above 1 ${\mu}g$/ml. In particular, saponin showed a protective effect on DNA oxidation. Furthermore, it was observed that saponin activates MMP-2 and increases MMP-1 activity in gelatin and casein zymography analyses, respectively, indicating that saponin could have potential a therapeutic agent for anti-aging and skin regeneration.

• Journal of the Korean Chemical Society
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• v.46 no.4
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• pp.363-377
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• 2002

The purpose of this study was to improve the problems of the voltaic cell described in the science textbooks of secondary schools. For this purpose, the contents of science textbooks which are related to the voltaic cell were analyzed and the problems which were not explained clearly by theorems were tried to be explained by experiments, and lastly sug-gestions were made toward the improvements regarding the voltaic cell in the science textbooks. The findings are that there are problems on the ways of ensuring whether the voltaic cell operates properly as a chemical battery, on the explanation of why the hydrogen bubbles form at the zinc electrode, on the cell potential, on the unification of the electrode terminology used, and on the mention of the current. Solutions to the problems except the cell potential were suggested. According to the experiment, the theoretical potential was calculated by considering the potentials of redox reactions at the two electrodes of the cell and by taking into account the characteristics of the electrodes such as the work function, ionization energy, stan-dard reduction potential, and electronegativity.The cell potential of the voltaic cell is explained by several factors. In the improved version of the textbook's introduction section to the voltaic cell, it is necessary to describe the voltaic cell his-torically.For the conceptual section, it should be explained in terms of the Daniel cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.369-377
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• 2013

In order to increase the utilization of sweet potato leaves and stalks as much as roots, it is necessary to study their beneficial potential. In this study, the antioxidant, antiallergic and anti-inflammatory effects of sweet potato leaves and stalks were evaluated by measuring total polyphenol and flavonoid contents, DPPH radical scavenging effects, the reducing power and inhibition effects on xanthine oxidase (XO), 5-lipoxygenase (LOX), and cyclo-oxygenase (COX)-2 activities. Blanched sweet potato leaves (SL), raw whole purple stalks (ST) and peeled stalks (PST) were freeze-dried and extracted with 95% ethanol. Total polyphenol content was highest in SL (11.03 mg/g), followed by ST (0.87 mg/g), and PST (0.37 mg/g). Total flavonoid content was highest for SL (9.01 mg/g), followed by ST (0.50 mg/g) and PST (0.25 mg/g). The $IC_{50}$ for DPPH radical scavenging effects was highest for SL ($43.6{\mu}g/mL$), followed by ST ($308.4{\mu}g/mL$) and PST ($1,631.3{\mu}g/mL$). The reducing power was highest for SL ($59.72{\mu}g$ ascorbic acid eq./mL), followed by ST ($12.56{\mu}g$ ascorbic acid eq./mL) and PST ($2.18{\mu}g$ ascorbic acid eq./mL) with $1,000{\mu}g/mL$ of ethanol extract. The inhibition rate on XO activity was highest for SL (13.06%), followed by ST (5.05%) and PST (0.0%) at $250{\mu}g/mL$ extract treatment. The inhibition rate on COX-2 activity was highest for SL (55.34%), followed by ST (2.18%) and PST (0.0%) at $250{\mu}g/mL$ extract treatment. The inhibition rate on 5-LOX activity was highest for SL (91.16%), followed by ST (33.38%) and PST (14.93%) at $50{\mu}g/mL$ treatment. Taken together, sweet potato leaves showed high antioxidative, anti-allergic and anti-inflammatory activities, especially with very strong inhibition effects on 5-LOX activity. These beneficial effects of sweet potato leaves might be mainly caused by the high content of polyphenols and flavonoids.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.311-316
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• 2016

This study was designed to develop the functional beverage using Salicornia herbacea L (SH). To evaluate the anti-oxidation and anti-thrombosis activities of SH, the ethanol extracts of leaf (LF), stem (ST) and seed (SD) of SH were prepared. Components analysis showed the total polyphenol of LF > ST > SD, and the total flavonoid of LF > SE > ST, respectively. Amounts of total sugar and reducing sugar of LF and ST were similar, but the SD had only 1/10 of sugar contents of LF. Anti-oxidation activities of each extract determined by calculated RC₅₀ showed LF > SD > ST for DPPH anion, nitrite and reducing power, and LF = SD > ST for ABTS cation scavenging activity, respectively. In anti-coagulation assay, SD showed strong inhibition activity against thrombin and blood coagulation factors. All the extracts had no platelet aggregation activities against human platelet and no hemolysis against human RBC. Our results suggest that the SD from SH has a great potential as a new anti-coagulation agent.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.177-183
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• 2004

Cytochrome P45O (CYP) contents and 7-ethoxyresorufin-O-deethylase (EROD) activity were determined in hepatic microsome of olive flounder (Paralichthys olivaceus) exposed to tributyltin chloride (TBTC), tributyltin oxide (TBTO), and triphenyltin chloride (TPTC). In addition, effects of in vivo (intraperitoneal injection of 7.5 mg $kg^{-1}$ BW) exposure of flounder to TPTC on CYP, NADPH cytochrome c reductase, NADH cytochrome b5 yeductase and EROD levels were measured. In in vitro exposure of hepatic microsome to organotins, TBTC, TBTO and TPTC reduced CYP contents and inhibited EROD activity. The TPTC was the strongest inhibitor, which is followed by TBTO and TBTC. The degree of inhibition, especially EROD acitivity, depended on the exposure duration. In addition, all the target enzymes in flounder were inhibited by TPTC with the in vivo exposure to TPTC. As EROD activity was the most sensitive to the inhibitions and demonstrated good reproducibility of the results, it could be used as a helpful tool toy monitor effects of organotin compounds on mixed funciton oxygenase system in marine fish.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.219-228
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• 2013

To understand characteristics of biogeochemical corrosion for the metal canisters that usually contain the radioactive wastes for a long-term period below the ground, some metal materials consisting of cast iron and copper were reacted for 3 months with D. desulfuricans, a sulfate-reducing bacterium, under a reducing condition. During the experiment, concentrations of dissolved metal ions were periodically measured, and then metal specimen and surface secondary products were examined using the electron microscopy to know the chemical and mineralogical changes of the original metal samples. The metal corrosion was not noticeable at the absence of D. desulfuricans, but it was relatively greater at the presence of the bacterium. In our experiment, darkish metal sulfides such as mackinawite and copper sulfide were the final products of biogeochemical metal corrosion, and they were easily scaled off the original specimen and suspended as colloids. For the copper specimen, in particular, there appeared an accelerated corrosion of copper in the presence of dissolved iron and bacteria in solution, probably due to a weakening of copper-copper binding caused by a growth of other phase, iron sulfide, on the copper surface.