• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.70-72
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• 2014

Visible-light irradiation of MeCN solution containing di(hydroxo)metallo(tetraphenyl)porphyrin complex $(tppM(OH)_2$: 1a; $M=Sb(V)^+Br^-$, 1b; $M=P(V)^+Cl^-$, 1c; M=Ge(IV)) and 2-mercaptoethanol (2-ME) as a substrate under aerated condition gave bis(2-hydroxyethyl)disulfide (2-HEDS) as an oxidative product of 2-ME. It is indicated that the oxidation of 2-ME should proceed with a photocatalytic process by 1, because the turn over number (TON) for the formation of 2-HEDS was over unit. The TON was determined to be 642 as a maximum value when 1a was used as a sensitizer. The formation of 2-HDES was extremely slow under argon atmosphere. The fluorescence of 1 was not quenched by 2-ME at all, and the free energy change (${\Delta}G$) with electron transfer (ET) from 2-ME to excited triplet state of $1(^31^*)$ was estimated as a negative value. The quenching rate constant ($k_r$) of $^31^*$ by 2-ME, obtained by the kinetics for the formation of 2-HEDS, strongly depends on ${\Delta}G$. These findings indicate that 1-sensitized oxidation was initiated by photoinduced ET from 2-ME to $^31^*$ to generate both radical cation of 2-ME ($2-ME^{+\bulle}$) and porphyrin radical anion ($1^{-\bulle}$), resulting that the formation of 2-HEDS can be proceeded by the dimerization of $2-ME^{+\bulle}$, and through a catalytic cycle due to returning to 1 by the ET from $1^{-\bulle}$ to molecular oxygen.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2005.04a
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• pp.100-102
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• 2005

양성자 빔을 이용한 치료는 종양부위에 높은 선량을 균일하게 전달하고 정상세포에는 적은 선량을 전달할 수 있어 암치료 효과가 높으나 정확한 치료와 환자의 안전을 위해서는 양성자선량의 급락지점을 정확히 아는 것이 중요하다. 본 연구에서는 양성자와 물질과의 핵반응으로 직각방향으로 방출되는 즉발감마선을 측정하여 양성자선량 급락지점을 측정할 수 있는 검출시스템을 몬테칼로 전산코드로 전산모사하였으며, 70MeV 단일에너지 빔과 최대에너지가 70MeV인 SOBP 빔을 모의피폭체인 물팬텀에 조사하고 검출시스템을 통해 직각방향으로 방출되는 즉발감마선의 분포를 계산하였다. 모의피폭체 안에서의 양성자선량의 분포와 측정된 즉발감마선의 분포를 서로 비교하여 두 분포 사이의 상관관계를 찾고 이 상관관계를 이용하여 양성자선량 급락지점을 결정할 수 있음을 확인할 수 있었다.

• ALGAE
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• v.20 no.3
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• pp.251-260
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• 2005

Antioxidative activities of Chlorophyta and Phaeophyta in Jeju Island were measured by superoxide anion ($O_2^{{\cdot}-}$), hydroxyl radical ($HO^{\cdot}$), hydrogen peroxide ($H_2O_2$) and DPPH free radical scavenging assays. Methanolic and aqueous extracts of the seaweeds were prepared at both temperatures, higher (70$^{\circ}C$) and room temperature (20$^{\circ}C$), and screened for the construction of an extract bank from seaweeds in Jeju Island. A variety of extracts showed positive effect against reactive oxygen species (ROS). Especially, Sargassum thunbergii methanolic extract at 70$^{\circ}C$ (70ME, 97.41%), S. fulvellum methanolic extract at 20$^{\circ}C$ (20ME, 84.66%), Codium fragile aqueous extract at 70$^{\circ}C$ (70AE, 96.61%) and S. thunbergii 20ME (97.44%) exhibited the highest scavenging activities against $O_2^{{\cdot}-}$, $HO^{\cdot}$, $H_2O_2$ and DPPH free radicals, respectively. Total phenolic contents also examined but did not show a positive correlation with ROS scavenging abilities (except for a few extracts). These results indicate that further investigation is needed to identify and purify the responsible antioxidative components.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.307-314
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• 2006

This study was conducted to screen in vitro angiotensin converting enzyme (ACE) inhibitory activities of methanol (MeOH) and aqueous extracts which were prepared by four different extractions-80% methanol extracts(ME) at $20^{\circ}C\;and\;70^{\circ}C$, respectively and aqueous extracts (AE) at both temperatures with the residue of the MEs-of ten marine green algae and nineteen brown algae collected along Jeju coast of Korea. Most marine brown algae extracts showed higher capacities than those of marine green algae in ACE inhibitory activity. Particularly, $70^{\circ}C$ MeOH extract (70ME) of Hizikia fusiforme showed the strongest inhibition activity (about 87%) among all the extracts. Also, 70 MEs of Enteromorpha linza, Ishige sinicola, Laminaria ochotensis, Petrospongium rugosum, Sagrassum horneri, Undaria pinnatifida and $20^{\circ}C$ MeOH extracts (20ME) of Myagropsis myagroides, Petrospongium rugosum, $20^{\circ}C$ aqueous extracts (20AE) of Codium contractum, Enteromorpha compressa, and $70^{\circ}C$ aqueous extracts (70AE) of Ecklonia cava, Petrospongium rugosum showed moderate ACE inhibitory activities more than 50% and the other extracts exhibited weak activities. On tile other hand, E. cava had the best ACE inhibitory activity among 70AEs. This indicates that 70AE of E. cava contains potential anti-ACE macromolecular. We tried to proteolytic digest 70AE of E. cava to induce production of anti-ACE peptides from E. cava 70AE. The enzymes used are five pretenses including Kojizyme, Flavourzyme, Neutrase, Alcalase, and Protamex, which are food grade-commercial enzymes from Novo Co. Flavourzyme-digest of E. cava 70AE showed the highest inhibitory activity about 90%. And the five different enzymatic digests of the E. cava 70AE ranged from 2.33 to 3.56 ${\mu}g/mL$, respectively in $IC_{50}$ values of anti-ACE activity.

• Journal of Mushroom
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• v.16 no.3
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• pp.170-174
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• 2018

This study aims to investigate the antifungal and protective effects of water- and 70% methyl alcohol-extracts from spent mushroom substrate (WESMS and MeOHSMS) of Lentinula edodes, on Botrytis cinerea- the causative agent for gray mold disease in ginseng. MeOHSMS inhibited mycelial growth and spore germination of Botrytis cinerea, by 75% and 95%, respectively. MeOHSMS could suppress gray mold disease of ginseng seedlings by 80% and effectively reduce the disease severity by 60%. Compared to the treatment of ginseng leaves with WESMS and DL-${\beta}$-aminobutyric acid (BABA), the MeOHSMS treatment increased the phenolic compounds in the leaves by 36% and 18%, respectively. These results suggest that the SMS extracts suppress gray mold disease in ginseng via dual functions: antifungal activity and increase in a plant defense factor-phenolic compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.210-219
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• 2017

This study aimed to establish an optimal extraction process and high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method for determination of marker compounds, dihydrokaempferol (DHK) and 3-O-methylquercetin (3-MeQ), as a part of materials standardization for the development of health functional foods from stems of Opuntia ficus-indica var. saboten (OFS). The quantitative determination method of marker compounds was optimized by HPLC analysis, and the correlation coefficient for the calibration curve showed very good linearity. The HPLC-PDA method was applied successfully to quantification of marker compounds in OFS after validation of the method in terms of linearity, accuracy, and precision. Ethanolic extracts from stems of O. ficus-indica var. saboten (OFSEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 50, 70, and 80% ethanol for 3, 4, 5, and 6 h. Among OFSEs, OFS70E at $80^{\circ}C$ showed the highest contents of DHK and 3-MeQ of $26.42{\pm}0.65$ and $3.88{\pm}0.29mg/OFS100g$, respectively. Furthermore, OFSEs were determined for their antioxidant activities by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibitory activities in rat liver homogenate. OFS70E at $70^{\circ}C$ showed the most potent antioxidant activities with $IC_{50}$ values of $1.19{\pm}0.11$ and $0.89{\pm}0.09mg/mL$ in the DPPH radical scavenging and LPO inhibitory assays, respectively. To identify active components of OFS, various chromatographic separation of OFS70E led to isolation of 11 flavonoids: dihydrokaempferol, dihydroquercetin, 3-O-methylquercetin, quercetin, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-galactoside, narcissin, kaempferol 7-O-glucoside, quercetin 3-O-galactoside, isorhamnetin, and kaempferol 3-O-rutinoside. The results suggest that standardization of DHK in OFSEs using HPLC-PDA analysis would be an acceptable method for the development of health functional foods.

• ALGAE
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• v.21 no.1
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• pp.149-156
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• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• Proceedings of the Korean Society for Information Management Conference
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• 2000.08a
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• pp.67-70
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• 2000

본 연구에서는 국내 의학학술논문의 저자가 선정한 주제용어(저자용어)와 MEDLINE 레코드의 MeSH 용어를 비교하여 국내 의학 학술논문 저자들이 얼마나 정확히 MeSH 용어를 사용하는지 일치도를 측정하였고, 사용방법상 어떠한 특징을 보이는지, 일치하지 않는 이유가 무엇인지 분석하였다. 1989년부터 1998년까지 Korean Journal of Parasitology에 발표된 415편의 논문에 사용된 1,826개의 저자용어 가운데 MEDLINE 레코드의 MeSH 용어와 일치한다고 볼 수 있는 용어는 35.5% (649개)로 한 논문에 평균 1.6개의 용어가 일치하였다. 이 가운데 완전히 일치하는 용어는 10.1%밖에 되지 않았다. 이와 같이 국내 의학학술논문 저자들은 MeSH 용어를 정확히 사용하기 위해 필수적인 체크태그 (Check tag), 계층구조 (Tree Structure), 부표목 사용 등 MeSH 용어 사용방법에 대한 지식이 부족한 것으로 나타났다.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.15 no.4
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• pp.558-565
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• 2008

Purpose: The purpose of this study was to analyze how accurately authors of the Journal of Korean Academy of Fundamentals of Nursing used MeSH terms as key words. Method: A total of 724 key words used in the 225 papers of Journal of Korean Academy of Fundamentals of Nursing from 2003 to 2007 were compared with MeSH terms. Results: Fifty nine point eight percent of total key words were completely coincident with MeSH terms, 13.5% were entry terms, and 21.8% were not MeSH terms. The coincidence rates for 2003 and 2007 separately were 38.5% and 70.9%. Also, 25.3% of papers precisely used MeSH terms as key words and 8% did not use any MeSH terms. Conclusion: The results show that the coincidence rate of key words with MeSH terms was at a moderate level and gradually increased according to year. However, there is a need for us to understand MeSH more specifically and accurately.

• Radioisotope journal
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• v.17 no.2
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• pp.70-79
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• 2002