• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1987년도 Proceedings of Korea-Japan Panax Ginseng Symposium 1987 Seoul Korea
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• pp.29-37
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• 1987

This study was devised to observe the cytotoxlc activities of petroleum-ether extract of Panax ginseng root(crude Gx) and its partially purified fraction from silicon acid column chromatography(7:3 CX) against sarcoma-180(5-180) and Walker carcinosarcoma 256(Walker 256) in vivo, and murine leukemic lymphocytes(L1210) and human rectal cancer cell(HRT-18) and human colon cancer cells(HT-29 and HCT-48) in vitro . Each cell-line was cultured in medium containing serial concentrations of the crude Gx or 7:3 Gx in vitro. A highly lipid soluble compound in the extract of Panax ginseng root was cytocidal to murine leukemic cells and human colon and rectal cancer cells in vitro In the meantime, ginseng saponin derivatives did not cytotoxic effects at its corresponding concentration. The growth rates of the cancer cells in medium containing ginseng extracts were inhibited gradually to a significant degree roughly in proportion to the increase of the extract concentration. The cytotoxic activity of 7:3 Gx was about 3 times more potent than that of crude Gx, one unit of cytotoxic activity against L121f cells being equivalent to 2.54$\mu\textrm{g}$ and 0.88 $\mu\textrm{g}$ for the crude Gx and 7:3 Gx, respectively. The Rf value of the active compound on silica -gel thin layer chromatography with petroleum-ether/ethyl ether/acetic acid mixture (90:10:1, v/v/v) as a developing solvent was 0.23. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times by the 7:3 Gx treatment compared with their control group. The significantly decreased hemoglobin values of rats after inoculation with Walker 256 were recovered to normal range by oral administration of the crude Gx. The synthetic levels of protein, DNA and RNA in human colon and rectal cancer cells were significantly diminished by treatment with the crude Gx, which can explain a part of the origin of its anticancer activity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.259-259
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• 2010

Periodically polarity inverted (PPI) ZnO structures on (0001) Al2O3 substrates are demonstrated by plasmas assisted molecular beam epitaxy. The patterning and re-growth methods are used to realize the PPI ZnO by employing the polarity controlling method. For the in-situ polarity controlling of ZnO films, Cr-compound buffer layers are used.[1, 2] The region with the CrN intermediate layer and the region with the Cr2O3 and Al2O3 substrate were used to grow the Zn- and O-polar ZnO films, respectively. The growth behaviors with anisotropic properties of PPI ZnO heterostructures are investigated. The periodical polarity inversion is evaluated by contrast images of piezo-response microscopy. Structural and optical interface properties of PPI ZnO are investigated by the transmission electron microcopy (TEM) and micro photoluminescence ($\mu$-PL). The inversion domain boundaries (IDBs) between the Zn and the O-polar ZnO regions were clearly observed by TEM. Moreover, the investigation of spatially resolved local photoluminescence characteristics of PPI ZnO revealed stronger excitonic emission at the interfacial region with the IDBs compared to the Zn-polar or the O-polar ZnO region. The possible mechanisms will be discussed with the consideration of the atomic configuration, carrier life time, and geometrical effects. The successful realization of PPI structures with nanometer scale period indicates the possibility for the application to the photonic band-gap structures or waveguide fabrication. The details of application and results will be discussed.

• 한국재료학회지
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• 제10권8호
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• pp.551-557
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• 2000

구리계 리드페임의 표면에 흑생산화물을 형성시키기 위하여 알칼리 용액에 담궈 산화시킨후 EMC(epoxy molding compound)로 몰딩하였고 기계적 가공을 하여 SDCB(sandwiched double-cantilever beam) 및 SBN(sandwiched Brazil-nut)시편을 만들었다. SDCB와 SBN 시편은 리드프레임/EMC 계면의 접착력을 각각 준 mode I 하중 및 혼합모드 하중 하에서 파괴인성치로 측정하기 위하여 고안되었다. 파괴경로를 밝혀내기 위하여 접착력 츨정 후에 얻어진 파면에 대하여 glancing-angle XRD, SEM, AFM, EDS 및 AES를 이용하여 분석하였다. SDCB 실험 후의 파면은 파괴되는 양상에 따라 세 가지 형태로 나눌 수 있었으며, 각 형태는 리드프레임의 접착전 표면 산화물 형성 상태와 밀접한 관계가 있었다. SBN 실험 후의 파면은 균열에서 가까운 부분과 먼 부분으로 나누어지는 특징을 보였는데, 이는 동적 파괴 효과(dynamic fracture effect)에 기인하는 것이라 생각된다. 또한 위상각에 따라 확실히 다른 파괴 양상을 보였는데, 이는 위상각에 따라 mode II 성분이 변하기 때문으로 생각된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.92-92
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• 2012

Chalcopyrite-type Cu(In,Ga)Se2 (CIGS) is one of the most attractive compound semiconductor materials for thin film solar cells. Among various approaches to prepare the CIGS thin film, the powder process offers an extremely simple and materials-efficient method. Here, we present the mechano-chemical synthesis of CIGS compound powders and their use as an ink material for screen-printing. During the synthesis process, milling time and speed were varied in the range of 10~600 min and 100~300 rpm, respectively. Both phase evolution and powder characteristics were carefully monitored by X-ray diffraction (XRD) method, scanning electron microscope (SEM) observation, and particle size analysis by scanning mobility particle spectrometer (SMPS) and aerodynamic particle sizer (APS). We found the optimal milling condition as 200 rpm for 120 min but also found that a monolithic phase of CIGS powders without severe particle aggregation was difficult to be obtained by the mechano-chemical milling alone. Therefore, the optimized milling condition was combined with an adequate heat-treatment (300oC for 60 min) to provide the monolithic CIGS powder of a single phase with affordable particle characteristics for the preparation of CIGS thin film. The powder was used to prepare an ink for screen printing with which dense CIGS thin films were fabricated under the controlled selenization. The morphology and electrical properties of the thin films were analyzed by SEM images and hall measurement, respectively.

• 한국환경농학회지
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• 제16권3호
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• pp.207-211
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• 1997

Bentazon의 잔류를 제거하기 위한 미나리의 생물학적 정화능력을 검정코자 $^{14}C-Bentazon$의 흡수(uptake)와 이행(translocation), 그리고 분해(metabolism) 실험을 통하여 비교 실험하였다. 잎에 처리한지 2일 후에 있어서 $^{14}C$의 21%가 처리된 잎에서 관측되었고, 66%는 잎 표면을 물로 세척한 곳에 잔류하고 있었으며, 나머지 13%는 epicuticular wax층에서 발견되었다. Bentazon을 처리한 잎으로부터 $^{14}C$의 79%가 검출되었으며, 뿌리에는 9%만이 검출되어 잎으로부터 뿌리로의 이행은 매우 적었다. 처리한 2일후에 $^{14}C$의 methanol 추출물 분석에서 잎에 처리된 제초제의 60% 이상이 모든 식물체 부위에서 분해되었다. 본 실험에서 발견된 주요 bentazon의 분해물(Metabolites)은 bentazon이나 6-hydroxy 혹은 8-hydroxy bentazon 보다 덜 이온화(Polar)된 알려지지 않은 신 물질(unknown compound)이었다.

• Food Science and Biotechnology
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• 제18권2호
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• pp.463-470
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• 2009

Sixteen antioxidative active compounds isolated from the EtOAc layer of MeOH extracts of kochujang, Korean fermented red pepper paste, were structurally elucidated as fumaric acid, methyl succinate, succinic acid furan-2-yl ester methyl ester (gochujangate, a novel compound), 2-hydroxy-3-phenylpropanoic acid, 3,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 6,7-dihydroxy-2H-chromen-2-one (esculetin), caffeic acid, cis-p-coumaric acid, trans-p-coumaric acid, daidzin, genistin, apigenin 7-O-$\beta$-D-apiofuranosyl($1{\rightarrow}2$)-$\beta$-D-glucopyranoside, apigenin 7-O-$\beta$-Dglucopyranoside, and quercetin 3-O-$\alpha$-L-rhamnopyranoside by mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments. These compounds were analyzed for the first time as antioxidants from kochujang.

• 대한화장품학회지
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• 제24권3호
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• pp.6-16
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• 1998

Ceramides are currently emerging as the major skin care ingredients due to !heir barrier properties in the stratum corneum of the human skin. Thus, major cosmetic companies have developed synthetic ceramide analogs for their own use. In this study, several ceramide mimic compounds , new skin barrier lipids, were designed and synthesized, and their physical and biological properties were investigated to evaluate their skin care capability. Several structures were designed from the variation of hydrophobic alkyl chain and hydrophilic moiety by the use of molecular modeling software. The selected targets were synthesized, and their properties and activities were studied as the pure form, in the emulsion, or in the lamellar mixture containing cholesterol and fatty acid. Some compounds, such as 1,3-bis(N-(2-hydroxyethyl)-palmitoylamino)-2-hydroxypropane, enhanced the restoration of skin barrier damaged by SDS(sodium dodecyl sulfate), and by acetone treatment. The rate of restoration was comparable to that of natural ceramides. The synthesized compounds alleviated SDS induced skin irritation and facilitated lamellar phase liquid crystal formation. The treatment of 1,3-Dis(N-(2-hydroxyethyl)-palmitoylam ino)-2-hyd roxypropane on the acetone damaged skin revealed that the compound promoted the recovery of intercellular lipid lamellar structure of stratum corneum layer. The replacement of palmitoyl groups of the compound with shorter alkyl chain gave lower emulsion viscosity and liquid crystal density, suggesting easier formulation and poorer barrier activity. Most of the synthesized compounds were non-irritable in various toxicological tests proving that they can be safely introduced to the skin care formulations.

• Mycobiology
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• 제41권4호
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• pp.234-242
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• 2013

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3645-3650
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• 2012

Two new blue emitting cationic iridium(III) complexes with two substituted 2-phenlypyridine ligands as main ligands and one 2,2'-biimidazole as an ancillary ligand, $[(L1)_2Ir(biim)]Cl$ (1) and $[(L2)_2Ir(biim)]Cl$ (2), where L1 = 2-(2',4'-difluorophenyl)-4-methylpyridine, L2 = 2-(2',4'-difluoro-3'-trifluoromethylphenyl)-4-methylpyridine and biim = 2,2'-biimidazole, were synthesized for applications in phosphorescent organic light-emitting diodes (PhOLEDs). Their photophysical, electrochemical and electroluminescent (EL) device performances were examined. The photoluminescent (PL) spectra revealed blue phosphorescence in the 450 to 485 nm range with a quantum yield of more than 10%. The iridium(III) compounds studied showed good solubility in organic solvents with no solvatochromism dependent on the solvent polarity. The solution-processed OLEDs were prepared with the configuration, ITO/PEDOT:PSS (40 nm)/mCP:Ir(III) (70 nm)/OXD-7 (20 nm)/LiF (1 nm)/Al (100 nm), by spin coating the emitting layer containing the mCP host doped with the iridium phosphors. The best performance of the fabricated OLEDs based on compound 1 showed an external quantum efficiency of 4.5%, luminance efficiency of 8.52 cd $A^{-1}$ and blue emission with the CIE coordinates (x,y) of (0.16, 0.33).

• 한국화재소방학회논문지
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• 제32권3호
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• pp.19-26
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• 2018

붕산과 5붕산암모늄으로 처리한 편백목재 시험편의 연소특성에 관한 실험을 ISO 5660-1 표준에 따른 콘칼로리미터를 이용하여 수행하였다. 그 결과 붕소화합물로 처리한 시험편의 화재성능지수(FPI)는 공시편보다 1.2~2.1배 증가하였고, 화재성장지수(FGI)는 공시편보다 1.6~8.4% 증가하였다. 또한 총연기발생률(TSR)은 공시편보다 9.0~28.3.% 낮았다. 이것은 붕소화합물로 처리한 시험편이 난연효과로 탄화층을 생성하기 때문으로 이해된다. 공시편은 418 s에서 가장 높은 CO농도인 0.01112%를 보였으나 붕소화합물로 처리한 시험편은 공시편보다 13.2~37.5% 감소하였다. 따라서 붕소화합물로 처리한 목재는 화재위험성과 위해성이 낮아질 것으로 예상된다.