• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1654-1663
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• 2018

Finding a safe and broad-spectrum medication is a goal of scientists, pharmacists, and physicians, but developing and fabricating the right medicine can be challenging. The current study describes the formation of silver nanoparticles (AgNPs) by Fusarium mangiferae. It involves the antibiofilm activity of the nanoparticles against Staphylococcus aureus. It also involves cytotoxic effect against mammalian cell lines. Well-dispersed nanoparticles are formed by F. mangiferae. The sizes of the nanoparticles were found to range from 25 to 52 nm, and UV-Vis scan showed absorption around 416-420 nm. SEM, TEM, and AFM results displayed spherical and oval shapes. Furthermore, the FTIR histogram detected amide I and amide II compounds responsible for the stability of AgNPs in an aqueous solution. AgNPs were observed to decrease the formation of biofilm at 75% (v/v). DNA reducing, smearing, and perhaps fragmentation were noticed after treating the bacterial cells with 50% (v/v). Additionally, cell lysis was detected releasing proteins in the supernatant. It was also observed that the AgNPs have the ability to cause 59% cervical cancer cell line (HeLa) deaths at 25% (v/v), however, they showed about 31% toxicity against rat embryo fibroblast transformed cell lines (REF). The results of this study prove the efficiency of AgNPs as an antibiofilm against S. aureus, suggesting that AgNPs could be an alternative to antibiotics. It must also be emphasized that AgNPs displayed cytotoxic behavior against mammalian cell lines. Further studies are needed for assessing risk in relation to the possible benefit of prescribing AgNPs.

• 분석과학
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• 제8권2호
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• pp.117-124
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• 1995

지속적인 음주로 인하여 간경변증으로 사망한 human 간에서 ethanol에 의해서 유도되는 것으로 추측되는 hemoprotein들을 확인 및 부분정제하였다. 이 hemoprotein을 정제하기 위하여 Mohamed 등의 방법을 변형하여 단백질을 정제하였고, SDS-PAGE 및 spectrum 양상을 관찰하였다. Triton N-101을 처리한 crude extract를 준비하여 CO gas를 bubbling시킨 후 Octyl-Sepharose CL-4B column chromatography에서 0.06% Lubrol PX로 용출한 다음 0.25% Lubrol PX로 용출하였다(Fig. 2). 0.06% Lubrol PX로 용출한 active fraction을 Hydroxyapatite와 DEAE-Sephadex A-25 column으로 정제하였다(Fig. 3, 4). 정제한 단백질을 12.5% SDS-PAGE를 실시한 결과 분자량은 대조군으로 사용한 흰쥐 간에서 정제한 단백질의 분자량은 55 KDa와 52 KDa였고, 돌연사한 사람의 간에서 정제한 단백질의 분자량은 62 48KDa이며, 간경변증으로 사망한 사람의 간에서 정제한 단백질의 분자량은 54KDa였고(Fig. 5). Cytochrome P450 함량은 20.8nmol/mg protein이며 회수율은 약 4.1%이고, 이들의 최대흡수 파장은 446nm이었다(Fig. 6).

• 생명과학회지
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• 제18권12호
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• pp.1752-1757
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• 2008

한국의 제주도와 서해안 염전의 해수로 부터 각각 빨강 (JU11-1), 노랑(JU14), 주황(TA20)의 색소를 생성하는 3 균주를 분리하였으며, 이들의 분류학적 특성 및 16S rRNA 서열 분석 결과 3 균주 모두 Pseudoalteromonas 속 세균으로 밝혀졌다. 이들 각각의 색소 최대 흡수파장은 각각 537, 378, 387 nm로 나타났다. 균주는 Marine broth 2216에서 잘 자랐으며, $30^{\circ}C$, 2% NaCl, pH 6-7 의 조건에서 Ju11-1과 Ju14는 배양 24 시간에, TA20은 배양 28 시간에 최대 색소 생성을 나타냈다. 탄소원으로 maltose를 1% 첨가하였을 경우 색소 생성이 우수하였으며, 질소원으로는 beef extract를 1% 첨가하였을 경우 최적의 색소 생성을 나타냈다.

• Applied Biological Chemistry
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• 제34권2호
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• pp.180-186
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• 1991

토양에서 분리한, 수용성 항진균성물질(solumycin)을 생산하는 Streptomyces sp. LAM-593의 배양액으로부터 butanol 추출, alumina와 2회의 Sephadex LH-20 column chromatography 등의 방법으로 물질을 정제하고 여러가지 성질을 조사한 결과는 다음과 같다. 본 물질은 silica gel TLC에서 단일 spot를 나타내었으며 ethanol-ammonia water-water (8:1:1). butanol-ethanol-water (5:1:4 및 5:2:2), 50% methanol계에서의 Rf치는 각각 0.24, 0.46, 0.57, 0.84였고, 물 methanol, acidic aq. butanol 등에 잘 용해하였으며 Fehling과 Molish 반응에서 양성인 342, 361. 380, 404nm에서 peak를 나타내는 heptaene계 물질이었다. 그리고 Candida, Cryptococcus, Saccharomyces, Trichophyton, Trichosporon 등의 진균에 대해서는 항균력이 컸으나 여러가지 세균에 대해서는 활성이 거의 없었다.

• 한국의류산업학회지
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• 제22권1호
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• pp.66-75
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• 2020

This study helps develop cool-touch functional dance sportswear. We suggest a draft design for dance sportswear that chooses appropriate cool-touch functional materials based on an investigation of the changes of body surface temperature before and after exercise, the physical properties of cool-touch materials on the market, and the preference for cooling tools. The results are as follows. First, cool-touch functional sportswear products on the market utilize materials such as PCM, Delta fabric, high gauge fabric, and ice chips as well as incorporate functions such as UV block and eyelets for enhanced breathability. Polyester and polyurethane fibers are mainly used for cool-touch functional sportswear. Second, the neck area showed the highest surface temperatures (32.7℃ and 32.1℃) before and after exercise. Body surface temperatures measured after exercise were also lower than temperatures measured before exercise when wearing dance sportswear. Third, as for the physical properties of cool-touch materials, material 1 showed amaximum drying speed (130 min), material 3 the best moisture absorption speed (122 × 132 min), and material 4 the best thermal conductivity (0.013 7 w/m·K). Fourth, a draft design for a cool-touch functional dance sportswear was suggested, including a neckband made of removable soft PVC material on the neck area and applying material 4 in F1, B4, S2 and lower arm areas and material 1 in the armpit area. Deodorant tape was also attached to the armpit area for added comfort and antibacterial deodorant effect.

• 한국재료학회지
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• 제23권5호
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• pp.260-265
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• 2013

Silicon nanoparticle is a promising material for electronic devices, photovoltaics, and biological applications. Here, we synthesize silicon nanoparticles via $CO_2$ laser pyrolysis and study the hydrogen flow effects on the characteristics of silicon nanoparticles using high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and UV-Vis-NIR spectrophotometry. In $CO_2$ laser pyrolysis, used to synthesize the silicon nanoparticles, the wavelength of the $CO_2$ laser matches the absorption cross section of silane. Silane absorbs the $CO_2$ laser energy at a wavelength of $10.6{\mu}m$. Therefore, the laser excites silane, dissociating it to Si radical. Finally, nucleation and growth of the Si radicals generates various silicon nanoparticle. In addition, researchers can introduce hydrogen gas into silane to control the characteristics of silicon nanoparticles. Changing the hydrogen flow rate affects the nanoparticle size and crystallinity of silicon nanoparticles. Specifically, a high hydrogen flow rate produces small silicon nanoparticles and induces low crystallinity. We attribute these characteristics to the low density of the Si precursor, high hydrogen passivation probability on the surface of the silicon nanoparticles, and low reaction temperature during the synthesis.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.382-382
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• 2012

CIGS thin films have received great attention as a promising material for solar cells due to their high absorption coefficient, appropriate bandgap, long-term stability, and low cost production. CIGS thin films are deposited by various methods such as co-evaporation, sputtering, spray pyrolysis and electro-deposition. The deposition technique is one of the most important processes in preparing CIGS thin film solar cells. Among these methods, co-evaporation is one of the best technique for obtaining high quality and stoichiometric CIGS films. However, co-evaporation method is known to be unsuitable for commercialization. The sputtering is known to be very effective and feasible process for mass production. In this study, CIGS thin films have prepared by rf magnetron sputtering using a $Cu(In_{1-x}Ga_x)Se_2$ single quaternary target without post deposition selenization. This process has been examined by the effects of deposition parameters on the structural and compositional properties of the films. In addition, we will explore the influences of substrate temperature and additional annealing treatment after deposition on the characteristics of CIGS thin films. The thickness of CIGS films will be measured by Tencor-P1 profiler. The crystalline properties and surface morphology of the films will be analyzed using X-ray diffraction and scanning electron microscopy, respectively. The optical properties of the films will be determined by UV-Visible spectroscopy. Electrical properties of the films will be measured using van der Pauw geometry and Hall effect measurement at room temperature using indium ohmic contacts.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.158-158
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• 2011

$Cu(In_xGa_{1-x})Se_2$ (CIGS) thin film solar cell is one of the most promising solar cells in photovoltaic devices. CIGS has a direct band gap which varied from 1.0 to 1.26 eV, depending on the Ga to In ratio. Also, CIGS has been studying for an absorber in thin film solar cells due to their highest absorption coefficient which is $1{\times}10^5cm^{-1}$ and good stability for deposition process at high temperature of $450{\sim}590^{\circ}C$. Currently, the highest efficiency of CIGS thin film solar cell is approximately 20.3%, which is closely approaching to the efficiency of poly-silicon solar cell. The deposition technique is one of the most important points in preparing CIGS thin film solar cells. Among the various deposition techniques, the sputtering is known to be very effective and feasible process for mass production. In this study, CIGS thin films have been prepared by rf magnetron sputtering method using a single target. The optical and structural properties of CIGS films are generally dependent on deposition parameters. Therefore, we will explore the influence of deposition power on the properties of CIGS films and the films will be deposited by rf magnetron sputtering using CIGS single target on Mo coated soda lime glass at $500^{\circ}C$. The thickness of CIGS films will be measured by Tencor-P1 profiler. The optical properties will be measured by UV-visible spectroscopy. The crystal structure will be analyzed using X-ray diffraction (XRD). Finally the optimal deposition conditions for CIGS thin films will be developed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.377-377
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• 2011

Organic solar cells (OSCs) with low cost have been studied to apply on flexible substrate by solution process in low temperature [1]. In previous researches, conventional organic solar cell was composed of metal oxide anode, buffer layer such as PEDOT:PSS, photoactive layer, and metal cathode with low work function. In this structure, indium tin oxide (ITO) and Al was generally used as metal oxide anode and metal cathode, respectively. However, they showed poor reliability, because PEDOT:PSS was sensitive to moisture and air, and the low work function metal cathode was easily oxidized to air, resulting in decreased efficiency in half per day [2]. Inverted organic solar cells (IOSCs) using high work function metal and buffer layer replacing the PEDOT:PSS have focused as a solution in conventional organic solar cell. On the contrary to conventional OSCs, ZnO and TiO2 are required to be used as a buffer layer, since the ITO in IOSC is used as cathode to collect electrons and block holes. The ZnO is expected to be excellent electron transport layer (ETL), because the ZnO has the advantages of high electron mobility, stability in air, easy fabrication at room temperature, and UV absorption. In this study, the IOSCs based on poly [N-900-hepta-decanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)] (PCDTBT) : [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) were fabricated with the ZnO electron-transport layer and MoO3 hole-transport layer. Thickness of the ZnO for electron-transport layer was controlled by rotation speed in spin-coating. The PCDTBT and PC70BM were mixed with a ratio of 1:2 as an active layer. As a result, the highest efficiency of 2.53% was achieved.

• 한국재료학회지
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• 제14권6호
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• pp.407-412
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• 2004

Photo decomposition of gas phase benzene by $TiO_2$ thin films chemically deposited on alumina balls were investigated under UV irradiation. Photo decomposition rates were measured in real time during the reaction using a photo ionization detector, which ionizes C-H bonding of benzene molecules and then converts into volatile organic compounds (VOCs) concentrations. From the measuring results, the VOCs concentration increased instantly when IN irradiated because C-H bonds of benzene molecules strongly absorbed on the surface of $TiO_2$ films before the IN irradiation was destroyed by photo decomposition. After that, the VOCs concentration decreased with increasing surface area of $TiO_2$ and reaction time under the IN irradiation. At the optimal conditions for the photo decomposition of gas phase benzene, the reaction rate of the photo decomposition for high concentrations (over 60 ppm) was slow but that of relatively low concentration (under 60 ppm) was fast, due to limited surface area of $TiO_2$ thin films for the reaction. Thus, it is concluded that the photo decomposition rate was mainly affected by the surface area of $TiO_2$ or absorption reaction.