• Title/Summary/Keyword: LED Cell

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Taxonomy and Fermentation of Kitasatosporia kimorexae Producing New Thiopeptide Antibiotics, Kimorexins

  • Yeo, Woon-Hyung;Kim, Si-Kwan;Kim, Sang-Seock;Yu, Seung-Hun
    • Journal of Microbiology and Biotechnology
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    • v.4 no.4
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    • pp.354-359
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    • 1994
  • An isolate, 90-GT-302, was found to produce antibiotics inducing typical mycelial swelling in Magnaporthe grisea and Fusarium solani. This isolate formed yellow substrate and white rectiflexbiles aerial mycelia in the early stages of growth. The aerial mycelium gradually changed its color to white and finally formed a gray spore mass. Analysis of the cell wall acid hydrolysate revealed the presence of LL- and meso-diaminopimelic acids, glycine, and galactose, which indicated cell wall type X. This result placed our isolate in genus Kitasatosporia. A comparison of isolate 9O-GT-302 with reference strains of Kitasatosporia spp., which not only demonstrated several differences in their physiological properties but also novelty of the active compounds produced by this isolate, led us to designate the isolate as Kitasatosporia kimorexae.

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Antitumor constituents from the sclerotium of Poria cocos

  • Li, Gao;Xu, Ming-Lu;Seo, Chang-Seob;Kim, Hyo-Jin;Lee, You-Jeong;Lee, Yeun-Koung;Lee, Chong-Soon;Woo, Mi-Hee;Son, Jong-Keun
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.256.3-257
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    • 2003
  • The bioactivity-guided fractionation of an active methylene chloride extract of the sclerotium of Poria cocos led to the isolation of compounds 1-5. These compounds were tested in the human colon carcinoma and human breast carcinoma cell lines, compounds 3, 4, and 5 exhibited IC50 values of 10.8, 15.4, and 5.1 $\mu\textrm{g}$/$m\ell$ against human colon carcinoma cell line. In addition, compounds 3, 4 and 5 showed moderate activities as inhibitors of Topoisomerase I and all compounds were inactive in the Topoisomerase II inhibition.

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Influence of defective sites in Pt/C catalysts on the anode of direct methanol fuel cell and their role in CO poisoning: a first-principles study

  • Kwon, Soonchul;Lee, Seung Geol
    • Carbon letters
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    • v.16 no.3
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    • pp.198-202
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    • 2015
  • Carbon-supported Pt catalyst systems containing defect adsorption sites on the anode of direct methanol fuel cells were investigated, to elucidate the mechanisms of H2 dissociation and carbon monoxide (CO) poisoning. Density functional theory calculations were carried out to determine the effect of defect sites located neighboring to or distant from the Pt catalyst on H2 and CO adsorption properties, based on electronic properties such as adsorption energy and electronic band gap. Interestingly, the presence of neighboring defect sites led to a reduction of H2 dissociation and CO poisoning due to atomic Pt filling the defect sites. At distant sites, H2 dissociation was active on Pt, but CO filled the defect sites to form carbon π-π bonds, thus enhancing the oxidation of the carbon surface. It should be noted that defect sites can cause CO poisoning, thereby deactivating the anode gradually.

Antitumor Agent from the Rhizome of Anemarrhena asphodeloides (지모(知母)의 항암활성성분에 관한 연구)

  • Lee, Seung-Ho;Ryu, Shi-Yong;Choi, Sang-Un;No, Zae-Sung;Kim, Sung-Ki;Lee, Chong-Ock;Ahn, Jong-Woong
    • Korean Journal of Pharmacognosy
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    • v.26 no.1
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    • pp.47-50
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    • 1995
  • EtOAc soluble part of MeOH extract of Anemarrhena asphodeloides rhizome was evaluated for the cytotoxicity against the five kinds of human tumor cell lines (A-549, SK-OV-3, SK-MEL-2, XF498 and HCT15) in vitro. Bioassay-guided fractionation of EtOAc soluble part led to the isolation of active compound which was identified as timosaponin A-III showed potent cytotoxic activity, but its genin, sarsasapogenin, did not show cell growth inhibition.

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Development of CRISPR/Cas9 system for targeted DNA modifications and recent improvements in modification efficiency and specificity

  • Shin, Juhyun;Oh, Jae-Wook
    • BMB Reports
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    • v.53 no.7
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    • pp.341-348
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    • 2020
  • The targeted nuclease clustered, regularly interspaced short palindromic repeats/CRISPR-associated proteins (CRISPR/Cas) system has recently emerged as a prominent gene manipulation method. Because of its ease in programming targeted DNA/protein binding through RNA in a vast range of organisms, this prokaryotic defense system is a versatile tool with many applications in the research field as well as high potential in agricultural and clinical improvements. This review will present a brief history that led to its discovery and adaptation. We also present some of its restrictions, and modifications that have been performed to overcome such restrictions, focusing specifically on the most common CRISPR/Cas9 mediated non-homologous end joint repair.

실리콘 박막 태양전지를 위한 CdSe계 양자점 광변환구조체

  • Sin, Myeong-Hun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.135.2-135.2
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    • 2014
  • Photon conversion technology for thin film solar cells is reviewed. The high-energy photons which are hardly absorbed in solar cells can be transformed the low energy photon by the photon conversion process such as down conversion or down shift, which can improve the solar cell efficiency over the material limit. CdSe-based quantum dot materials commonly used in LED can be used as the photon conversion layer for Si thin film solar cells. The photon conversion structure of CdSe-based quantum dot for Si thin film solar cells will be presented and the pros and cons for the Si thin film solar cells integrated with the photon conversion layers will be discussed.

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Optimization of Energy Consumption in Cellular Access Networks (셀룰러 망의 에너지 소모 최적화 기법)

  • Lee, Jung-Girl;Back, Ju-Hoon;Choi, Yong-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.2
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    • pp.53-60
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    • 2014
  • The recent electric power shortage has led to the vigorous study for energy conservation in the many different fields. In this paper, cell zooming technology, which can reduce the energy loss at the base stations controlling the transmission power of the stations depending on the changing trffic density for reduce energy consumption that occurs when there is little or no trffic in the service area, is proposed and energy conservation is confirmed by comparing base stations' service scenario depending on traffic change.

Toxicity and Biomedical Imaging of Fluorescence-Conjugated Nanoparticles in Hematopoietic Progenitor Cells

  • Min, Gye-Sik;Kim, Dong-Ku
    • Reproductive and Developmental Biology
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    • v.35 no.4
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    • pp.503-510
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    • 2011
  • Cellular uptake of nanoparticles for stem cell labeling and tracking is a critical technique for biomedical therapeutic applications. However, current techniques suffer from low intracellular labeling efficiency and cytotoxic effects, which has led to great interest in the development of a new labeling strategy. Using silica-coated nanoparticles conjugated with rhodamine B isothiocyanate (RITC) (SR), we tested the cellular uptake efficiency, biocompatibility, proliferation or differentiation ability with murine bone marrow derived hematopoietic stem/progenitor cells. The bone marrow hematopoietic cells showed efficient uptake with SR with dose or time dependent manner and also provided a higher uptake on hematopoietic stem/progenitor cells. Biocompatibility tests revealed that the SR had no deleterious effects on cell cytotoxicity, proliferation, or multi-differentiation capacities in vitro and in vivo. SR nanoparticles are advantageous over traditional labeling techniques as they possess a high level of cellular internalization without limiting the biofunctionality of the cells. Therefore, SR provides a useful alternative for gene or drug delivery into hematopoietic stem/progenitor cells for basic research and clinical applications.

Deposition of Al/Ti electrode layer on PET substrate using ebeam and optimization of electrical properties

  • Danish, Rehan;Anwar, M.S;Koo, Bon Heun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.221-221
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    • 2014
  • The current energy crisis in many countries has led to the search of an efficient renewable energy source. Among those the solar energy is the most abundant and easily available. However harvesting the solar energy requires a much efficient device. Lot of research has been done in this regard and so far the efficiency of traditional solar cell stands around ~50% and for PET films it is much lesser. The potential application of PET films in the solar cells can be very promising provided the fact that the PET film is lighter and logistically more viable. There is a lot of work that is being done to increase the efficiency of PET based solar cells. The base electrode plays a vital role in increasing the efficiency of the cell.

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Electrode of Low Impedance by Polypyrrole Addition for Supercapacitor (폴리피롤 첨가에 의한 supercapacitor용 저 임피던스 전극)

  • 김경민;장인영;강안수
    • Proceedings of the Safety Management and Science Conference
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    • 2003.11a
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    • pp.343-350
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    • 2003
  • The best Ppy weight ratio was 7 wt% and the optimal electrode composition ratio was 78 : 17 : 5 wt.% of (MSP-20 : BP-20 =1 : 1), (Super P : Ppy =10 : 7) and P(VdF-co-HFP). Implantation of Ppy as the conducting agents have led to superior electrochemical characteristics because of the low of internal resistance and faradaic capacitance. The result of unit cell with Ppy 7 wt% were as follows: 28.02 Fig of specific capacitance, 1.34 Ω of DC-ESR and 0.36 Ω of AC-ESR. Unit cell showed a good stability up to 200 charge-discharge cycles, retaining 82% of their original capacity at 200 cycles. From the analysis of impedance, the electrodes with Ppy 7 wt% showed low ESR, low charge transfer resistance and quick reaction rate. It was inferred that quick charge-discharge was possible. As compared with the specific capacitance (rectangular shape) of CV, it was also concluded that the specific capacitance originated from thecompound phenomena of the faradaic capacitance by oxidation and reduction of Ppy and the non-faradaic capacitance by adsorption-desorption of activated carbon.

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