• Food Science and Preservation
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• v.16 no.3
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• pp.435-441
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• 2009

Activity-guided isolation from the ethylacetate (EtOAc)-soluble portion of a methanolic extract of the seeds of Eriobotrya japonica, using several bioassays, led to the isolation and identification of six phenolic compounds of previously known structure: benzaldehyde (1), chlorogenic acid (2), caffeic acid (3), benzoic acid (4), ferulic acid (5), and amygdalin (6). Of these, benzaldehyde (1) exhibited tyrosinase inhibitory activity in a bioassay. In addition, chlorogenic acid (2) and caffeic acid (3) were found to have strong antioxidative effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.1
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• pp.37-43
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• 2013

Conductivity of LSGMC materials were affected by secondary phase segregation, composition and synthetic route. $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.1}Co_{0.1}O_{3-{\delta}}$ (LSGMC) powders were prepared using the glycine nitrate process to produce high surface area and compositionally homogeneous powders. The powders were synthesized with different 0.5, 1, 1.5, 2, 2.5 of glycine/cation molar ratios. A single perovskite phase from the synthesized powders was characterized with X-ray diffraction patterns. The obtained sintered pellets showed the dense grain microstructure. In case of 1.5 molar ratio, its density was higher than the others. The electrical conductivity measured at $800^{\circ}C$ was observed to be 0.131 $Scm^{-1}$. In addition, the linear thermal expansion behavior was indicated between $25^{\circ}C$ and $800^{\circ}C$.

• Journal of Life Science
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• v.25 no.11
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• pp.1298-1303
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• 2015

Machilus thunbergii (Lauraceae) is an evergreen tree cultivated in Korea and Japan. M. thunbergii has long been used as a traditional medicine in Korea, China, and Japan to treat various diseases, including edema, abdominal pain, and abdominal distension. In this study, dried stem bark of M. thunbergii extracted in methanol and extract was partitioned into n-hexane, CHCl₃, and BuOH. The CHCl₃-soluble extracts chromatographed on silica gel column using a CHCl₃/acetone and n-hexane/EtOAc mixture to afford Compound 1 and 2. Two dibenzylbutane lignans, macelignan (1) and meso-dihydroguaiaretic acid (2), were isolated from the CHCl₃-soluble extract of M. thunbergii stem bark. The structures of 1 and 2 were determined by ¹H- and ¹³C-NMR spectroscopic data analyses and a comparison with literature data. The tyrosinase inhibitory activity of the isolated compounds was evaluated. Among these compounds, Compound 2 strongly inhibited the monophenolase (IC₅₀=10.2 μM) activity of tyrosinase. A kinetic analysis showed that Compound 2 was a competitive inhibitor. The apparent inhibition constant (K_i) for Compound 2 binding to free enzyme was 4.8 μM. Based on these results, it can be concluded that meso-dihydroguaiaretic acid (2) is a potential candidate for the treatment of melanin biosynthesis-related skin diseases.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.607-612
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• 1986

최근 테니스의 저변인구가 크게 증가함에 따라 테니스 라켓의 제작기술도 상당한 수준에 이르렀고 설계제작의 자동화에 의해서 양질의 제품이 시판되고 있다. 그러나 라켓에 볼이 임팩트될때 생기는 진동으로 야기되는 테니스 엘보우 등, 해결해야 할 문제들이 아직도 남아 있다. 이와같이 테니스 라켓의 정적인 강도 뿐만아니라 동적인 특성도 중요한 관심의 대상이 되어감에 따라 볼 컨트롤을 용이하게 한다거나, 안정타점영역(Sweet Spot)의 확장과 그립부의 진동등에 의해서 발생하는 엘보우 현상을 방지하기 위해 여러가지 연구가 수행되어 왔다. 특히, 다차원 스펙트럼해석 및 모우드 해석법에의해 그립부에 미치는 진동원의 동정과 라켓의 동적거동에 대해서 연구되었고, 라켓의 재질변경과 그립부의 구조변경에 의한 안정타점영역에 영향을 미치는 모우드 파라미터(Modal Parameter)의 추정에 관한 연구도 수행되었다. 이러한 연구들은 결국 안정타점영역을 확장시키거나 테니스 엘보우를 방지하기 위한 것으로서 이러한 목적을 달성하기위해 테니스 라켓의 진동 모우드에 관계되는 파라미터들을 찾아서 그 모우드 파라미터의 변화에 따르느 진동 모우드의 거동에 대해서 연구할 필요가 있다. 본 논문에서는 실험적인 모우드 해석법을 실제 테니스 라켓에 적용하여 모우드 파라미터들을 구한 다음 그 파라미터의 변화에 따르는 안정타점영역의 변화를 컴퓨터 시뮬레이션을 통해서 예측하였다. 또한 안정타점영역을 넓히고 라켓의 동특성을 개선시킬 수 있는 모우드 파라미터를 찾아서 테니스 라켓의 설계, 제작 단계에 정보를 제공하는 CAD(Computer Aided Design)에 좋은 자료를 얻고자 한다. 있으나 파도에 의한 영향이 가장 크므로 본 논문에서는 파도에 의한 영향만을 고려하였다. 파도는 쌍동선에 외란으로 작용하며 측정할 수 없는 양이므로 PID, LQ 제어에서는 제어모델에 포함되지 않지만 LQG 제어에서는 제어모델에 포함된다. LQG 제어의 경우 제어모델에 파도를 백색잡음으로 가정하고 제어기를 구성한 것 (LQG1)과 2차의 쉐이핑필터(shaping filter)를 사용하여 구성한 것(LQG2)으로 나누었다.져 한다.) 식도 이물에 의한, 또는 식도경술에 의한 합병증이 초래한 경우는 식도점막열상 1례 (1.8 %), 식도 천공 1례 (1.8 %) 였으며, 기도이물에 의한, 또는 기관지경술에 의한 합병증이 초래한 경우는 무기폐 2례 (11.1 %), 폐렴 3례 (16.7 %)로 나타났다.5예에서 소실되었다. 5 ) 청각심리검사 (Psychoacoustic evaluation)에서 폴립은 술전에 Grade 1∼2의 사성이 있었던 11예중 술후 10예에서 Grade 0로 되었으며 Grade 1∼2의 사성이 있었던 3예의 결절에서도 모두 Grade 0로 정상화되었다.>치를 측정한 결과 투여전과 차이가 없었다. 7) 이상의 결과로 볼때 Cis-platinum 사용으로 인한 이중독증은 신장기능이 정상일때는 충분한 hydration으로써 예방이 가능하며 동시에 금기로 알려져왔던 감음성난청이 있는 두경부악성종양환자에서도 세심한 주의하에 적절히 사용한다면 좋은 결과를 얻을 수 있을 것으로 사려된다.은 결과를 얻었기에 문헌고찰과 함께 보고하는 바이다. 1) 이관폐쇄술후 18시간에 최초로 삼출액이 확인되었으며 그 이후는 전실험군에서 삼출성중이염이 유발되다. 2

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.309-315
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• 2009

In our search for the natural cosmetic ingredients, we found that Euryale ferox seed extract exhibited the strong antioxidative activity. Five active compounds were isolated from the ethyl acetate extract through various chromatographic methods and their structures were determined by NMR and MS spectral analysis. These compounds were identified as fucosterol (1), 3-(4-hydroxy-3-methoxybenzyl)-4-[(7'R),5'-dihydroxy-3'-methoxybenzyl]tetrahydrofuran (2), resorcinol (3), pyrogallol (4) and 4-O-methylgallic acid (5).We evaluated the antioxidative, antielastase activities and melanogenesis inhibitory effects of these compounds. The $SC_{50}$ values of compounds 2 ~ 5 for free radical scavenging activity were $17.0\;{\sim}\;100.2\;{\mu}M$ and especially compounds 4 and 5 were 6-fold more effective than ferulic acid as a positive control. And compounds 2 ~ 4 inhibited human neutrophil elastase with $IC_{50}$ values of $18.8\;{\sim}\;78.2\;{\mu}M$ and compound 3 also inhibited melanin synthesis in B16F10 melanoma cells with an $IC_{50}$ value of $492.8\;{\mu}M$. These results suggest that Euryale ferox extract having a lot of various active ingredients may be useful as a natural multi-functioning agent.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.341-351
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• 2019

In this study, we investigated anti-oxidative and anti-bacterial constituents from Rhododendron weyrichii leaves. DPPH and ABTS⁺ radical scavenging activities were screened for the ethanol extract and solvent fractions. Potent scavenging activities were appeared from the extract, ethyl acetate (EtOAc) and n-butanol (BuOH) fractions. Upon the anti-bacterial tests using Staphylococcus epidermidis and Propionibacterium acnes, extract, n-hexane (Hex) and EtOAc fractions showed strong activities. To isolate the active constituents, the EtOAc fraction was further purified to afford five phytochemicals; ursolic acid (1), corosolic acid (2), asiatic acid (3), astragalin (4) and isoquercetin (5). All of the compounds 1-5 were isolated for the first time from this plant. Among the isolates, the compound 4 and 5 showed strong DPPH and ABTS⁺ radical scavenging activities. Also, compound 3 exhibited the most potent anti-bacterial activity. In addition, the content of astragalin isolated from this plant was determined by UPLC and the quantity was about 8.1 mg/g for the 70% ethanol extract and 34.8 mg/g for the EtOAc fraction. Based on these results, it is concluded that R. weyrichii extract could be potentially applicable as anti-oxidative and anti-bacterial ingredients in cosmetic formulations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.3
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• pp.207-218
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• 2020

In this study, the anti-inflammatory and anti-bacterial activities of the extracts from the leaves of the Hydrangea petiolaris were identified, and the chemical structure was identified by separating the active ingredient. As the result of the anti-inflammatory activity experiment using RAW 264.7 cells, it was confirmed that the n-hexane (Hex) and ethyl acetate (EtOAc) fractions inhibited the production of nitric oxide (NO) and the expression of iNOS protein in a concentration-dependent manner without cytotoxicity. In addition, the n-Hex and EtOAc fractions reduced the production of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6). Upon the anti-bacterial tests using Staphylococcus epidermidis and Cutibacterium acnes, the extract, n-Hex, EtOAc and n-butanol (BuOH) fractions showed potent activities. In order to isolate the active constituents, the n-Hex and EtOAc fractions were further purified to afford four phytochemicals; phytol (1), corosolic acid (2), asiatic acid (3) and 1-O-p-coumaroyl-β-D-glucopyranoside (4). All of the compounds 1 - 4 were isolated for the first time from this plant. In addition, the contents of isolated compounds were determined by HPLC and the quantity of phytol (1) was 27.8 mg/g for the 70% EtOH extract. Based on the above research results, it is believed that it will be possible to develop a natural cosmetic material that has anti-inflammatory and anti-bacterial effects using the extract of H. petiolaris leaves.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.87-98
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• 2020

The bird track fossil site in Haman Formation is divided into seven sedimental layers by the sedimentary structures, lithofacies and sequences. The bird tracks top on the highest layer, which includes ripple marks and suncracks. The layer has lithofacies with reddish grey siltstone and dark grey mudstone, alternately. As an analysis for the same rocks of the fossil site, physical properties show on mean values for 0.62% of absorption rate, 1.64% of porosity and 2.63 of specific gravity. Rock-forming minerals composed mainly of plagioclase, quartz, calcite, chlorite and mica. Meanwhile, we executed an experiments based on the petrography and weatherings to find a proper consolidants. In the experiments, the OH 100 reagent proved stable aspect and the lowest transition rate in terms of weight and chromaticity. Also, it showed the highest increase in ultrasonic velocity, improving the physical properties of the rocks. In the case of applying the OH 100 with antihygro, an swelling inhibitors on the sedimentary rocks, the chromaticity indicated an stable transition aspect. When it comes to the physical properties, the antihygro also decreases the porosity effectively. Thus, the most proper method for the fossil site of Haman Formation is to apply antihygro and OH 100 reagents since the rocks includes clay minerals that show swelling characteristics. However, this result is deduced from an indoor application experiments, leaving the necessity of verification how these reagents would affect the bird tracks site under the field condition.

• Applied Microscopy
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• v.38 no.1
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• pp.29-34
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• 2008

Small amounts of zinc ions regulate a plentitude of enzymatic proteins, receptors and transcription factors, thus cells need accurate homeostasis of zinc ions. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartment ("vesicular zinc"), which can be evidenced using histochemical techniques. These neurons are the socalled zinc enriched (ZEN) neurons, which accumulate glutamate and zinc inside their synaptic vesicles and release it during synaptic transmission. In the present paper we have studied the distribution of the ZEN terminals in the rat hippo-campus using ZnSe autometallography, Neo-Timm staining, ZnT3 immunohistochemistry and TSQ fluorescence staining.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1385-1390
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• 2016

Gallic acid is a representative hydroxybenzoic acid and is found in free form in several plants and in various esterified forms as a part of hydolyzable tannins. Convenient enzymatic transformation of trihydroxylated gallic acid with polyphenol oxidase originating from pear was evaluated to investigate whether polyphenol oxidase can be used as a valuable compound to improve the biological activity of gallic acid. Enzymatic oxidation processing of gallic acid using polyphenol oxidase was carried out for five different reaction times. The antioxidant effects of transformed gallic acid for different reaction times were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. In addition, the anti-diabetic property of the transformed gallic acid was measured based on ${\alpha}$-glucosidase. Gallic acid reacted for 5 h showed significantly higher antioxidant and ${\alpha}$-glucosidase inhibitory activities compared to the tested positive control substances. Biotransformation of simple gallic acid induced by polyphenol oxidase might be responsible for enhancing the biological activity of gallic acid.