• 제목/요약/키워드: cell division

검색결과 5,282건 처리시간 0.033초

Effusion Cell 방식에 의한 <111> 결정구조의 Au 박막의 제작 (Au Thin Film Fabrication of <111> Crystal Structure by Effusion Cell Process)

  • 표경수;김강대;김용규;송정근
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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    • pp.383-386
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    • 2004
  • The one of important requisites for fabricating molecular electronic device is the single crystal direction of bottom substrate nowadays. [1,2]. We obtain the optimum SAM result when the Au crystal is <111> structure for Self-Assembled molecular. To get the <111> crystal Au, we generally repeat heating and cooling course after evaporating Au [3]. However, we can fabricate <111> crystal Av thin film except post treatment because we simultaneously evaporate and anneal using Effusion Cell. In this paper, we study on thin film growth of <111> crystal Au as bottom electrode which is essential for Self-Assembled molecular by Effusion Cell and analyze crystal structure, thickness, surface conductivity and so on as each process condition.

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CdSe-sensitized Photoelectrochemical Solar Cell Prepared by Spray Pyrolysis Deposition Method

  • Im, Sang-Hyuk;Lee, Yong-Hui;Seok, Sang-Il
    • 전기화학회지
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    • 제14권2호
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    • pp.104-109
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    • 2011
  • We fabricated CdSe-sensitized photoelectrochemical solar cell by depositing CdSe nanoparticles on nanoporous $TiO_2$ (np-$TiO_2$) via spray pyrolysis deposition method. By adjusting the amount of CdSe-sensitizer deposited on np-$TiO_2$, we can fabricate an efficient CdSe-sensitized solar cell (${\eta}$ = 3.0% under 1 sun irradiation) in polysulfide liquid electrolyte.

MEASURING CROWN PROJECTION AREA AND TREE HEIGHT USINGLIDAR

  • Kwak Doo-Ahn;Lee Woo-Kyun;Son Min-Ho
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.515-518
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    • 2005
  • LiDAR(Light Detection and Ranging) with digital aerial photograph can be used to measure tree growth factors like total height, height of clear-length, dbh(diameter at breast height) and crown projection area. Delineating crown is an important process for identifying and numbering individual trees. Crown delineation can be done by watershed method to segment basin according to elevation values of DSMmax produced by LiDAR. Digital aerial photograph can be used to validate the crown projection area using LiDAR. And tree height can be acquired by image processing using window filter$(3cell\times3cell\;or\;5cell\times5cell)$ that compares grid elevation values of individual crown segmented by watershed.

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Light-susceptibility of Camptothecin Production from in Vitro Cultures of Camptotheca acuminata Decne

  • Park, Young-Goo;Park, Mee-Hee;Yang, Jae-Kyung;Chung, Young-Gwan;Park, Myung-Suk
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제8권1호
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    • pp.32-36
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    • 2003
  • Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.

Effects of Nitrogen and Sodium on Growth in Phaeodactylum tricornutum (Bacillariophyceae)

  • Lee Soon Jeong;Choi Han Gil;Nam Ki Wan
    • Fisheries and Aquatic Sciences
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    • 제3권2호
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    • pp.151-155
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    • 2000
  • Phaeodactylum tricornutum (Bacillariophyceae) is a marine diatom which has been supplied as a food of bivalves. In this study, growth responses of P. tricornutum to some nitrogen sources and sodium were investigated by measuring cell number and contents of chlorophyll a in culture. In medium with nitrogen and sodium, brisk cell division occurred and maximum growth rate was respectively found in the medium with 150 mg/l of nitrate and 10 mg/l of ammonium and urea. At 10-500 mg/l ammonium and urea and 200-500 mg/l nitrate, specific growth rate decreased slightly. However, no cell division observed in sodium-deficient medium, regardless of presence or absence of nitrogen. This suggests that sodium is required for the nitrogen uptake of P. tricornutum, resulting nitrogen uptake leading to cell division. Also the upper limits of ammonium and nitrate for the growth of P. tricornutum seem to be 10 mg/l and 500 mg/l, respectively.

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Biochemical Changes in Sugars and Cell Wall Degrading Enzymes during Ripening of Banana

  • Lee, Min-Kyung;Kim, Mi-Jeong;Park, Inshik
    • Preventive Nutrition and Food Science
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    • 제9권1호
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    • pp.92-94
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    • 2004
  • Changes in reducing sugar and cell wall degrading enzymes during ripening of banana for 10 days were investigated. The amount of reducing sugar in bananas increased during storage at room temperature during the first 7 days, and decreased thereafter. However, starch content in banana decreased during ripening, and invertase and cell wall degrading enzymes such as cellulase, polygalacturonase and xylanase were most active after bananas were stored for 7 days at room temperature. When the bananas were stored at 4$^{\circ}C$, the magnitude of changes were much less than during room temperature storage.

Use of High-Temperature Gas-Tight Electrochemical

  • Park, Jong-Hee;Beihai Ma;Park, Eun-Tae
    • The Korean Journal of Ceramics
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    • 제4권2호
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    • pp.103-113
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    • 1998
  • By using a gas-tight electrochemical cell, we can perform high-temperature coulometric titration and measure electronic transport properties to determine the elecronic defect structure of metal oxides. This technique reduces the time and expense required for conventional thermogravimetric measurements. The components of the gas-tight coulometric titration cell are an oxygen sensor, Pt/yttria stabilitized zirconia(YSZ)/Pt, and an encapsulated metal oxide sample. Based on cell design, both transport and thermodynamic measurements can be performed over a wide range of oxygen partial pressure ($pO_2=10^{-35}$ to 1 atm). This paper describes the high-temperature gas-tight electrochemical cells used to determine electronic defect structures and transport properties for pure and doped-oxide systems, such as YSZ, doped and pure ceria $(Ca-CeO_2 \;and\; CeO_2)$, copper oxides and copper-oxide-based ceramic superconductors, transition metal oxides, $SrFeCo_{0.5}O_x,\; and \;BaTiO_2$.

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An Anti-apoptotic Protein Human Survivin is a Direct Inhibitor of Caspase-3 and -7

  • Sejeong Shin;Oh, Byung-Ha
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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    • pp.34-34
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    • 2001
  • Survivin, an apoptosis inhibitor/cell-cycle regulator, is critically required for suppression of apoptosis and ensuring normal cell division in the G2/M phase of the cell cycle. It is highly expressed in a cell cycle-regulated manner and localizes together with caspase-3 on microtubules within centrosomes. Whether survivin is a physiologically relevant caspase inhibitor has been unclear due to the difficulties with obtaining correctly folded survivin and finding right conditions for inhibition assay.(omitted)

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Follistatins have potential functional role in Porcine Embryogenesis

  • Kim, Dong-Hee;Chun, Ju Lan;Lee, Ji Hye;Kim, Keun Jung;Kim, Eun Young;Lee, Bo Myeong;Zhuang, Lili;Kim, Min Kyu
    • 농업과학연구
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    • 제43권1호
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    • pp.52-60
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    • 2016
  • In animal reproduction, the quality of oocytes and embryos has been evaluated by the expression of specific molecules. Follistatin (FST), which was isolated from follicular fluid, binds and bio-neutralizes the TGF-${\beta}$ superfamily members. Previous studies using the bovine model showed FST could be an important molecular determinant of embryo developmental competence. However, the effect of FST treatment on porcine embryo developmental competence has not been established. In this study, the effect of exogenous FST on porcine embryo developmental competence was investigated during in vitro culture. FST (10 ng/ml) treatment induced a significant decrease in the rate of cell arrest at the 4-cell stage. The expression levels of DNA-methyltransferase 1 (DNMT1), histone deacetylase 1 (HDAC1), and histone deacetylase 2 (HDAC2) were decreased in 4-cell stage embryos. FST treatment also resulted in significant improvements in developmental competence of embryos in terms of blastocyst formation rate and OCT-4 mRNA levels, the latter being related to pluripotency. In conclusion, during in vitro culture, FST treatment significantly ameliorated 4-cell block during embryonic development and improved embryo developmental competence. Therefore, FST treatment may potentially have a functional role in porcine embryogenesis that is broadly applicable to enhance in vitro embryo development.

Identification and extensive analysis of inverted-duplicated HBV integration in a human hepatocellular carcinoma cell line

  • Bok, Jeong;Kim, Kwang-Joong;Park, Mi-Hyun;Cho, Seung-Hak;Lee, Hye-Ja;Lee, Eun-Ju;Park, Chan;Lee, Jong-Young
    • BMB Reports
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    • 제45권6호
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    • pp.365-370
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    • 2012
  • Hepatitis B virus (HBV) DNA is often integrated into hepatocellular carcinoma (HCC). Although the relationship between HBV integration and HCC development has been widely studied, the role of HBV integration in HCC development is still not completely understood. In the present study, we constructed a pooled BAC library of 9 established cell lines derived from HCC patients with HBV infections. By amplifying viral genes and superpooling of BAC clones, we identified 2 clones harboring integrated HBV DNA. Screening of host-virus junctions by repeated sequencing revealed an HBV DNA integration site on chromosome 11q13 in the SNU-886 cell line. The structure and rearrangement of integrated HBV DNA were extensively analyzed. An inverted duplicated structure, with fusion of at least 2 HBV DNA molecules in opposite orientations, was identified in the region. The gene expression of cancer-related genes increased near the viral integration site in HCC cell line SNU-886.