• 제목/요약/키워드: growth modification

검색결과 344건 처리시간 0.027초

훼손지 유형에 따른 생태복원 평가방법 개발 (Evaluation Method Development for Ecological Restorations by Damaged Types)

  • 최재용;이상혁;이솔애;지승용;이상훈
    • 한국환경복원기술학회지
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    • 제19권1호
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    • pp.121-133
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    • 2016
  • It was required to evaluate ecological restorations in a comprehensive way in order to systematically manage conservation areas such as DMZ and national parks in South Korea. In this research we developed a new approach to evaluating ecological restorations with more various indexes than vegetation covering-related indexes. By analyzing damaged areas in the vicinity of DMZ, major damaged types were identified as six classes: landform modification, surface loss, soil pollution, soil physio-chemical modification, vegetation decline and vegetation damaged. From literature review, 39 indexes were selected and were grouped into four divisions: soil property, vegetation growth & structure, habitat property and landscape structure & functions. By conducting a survey with the selected indexes targeting relevant experts, data on relative importance among the divisions and indexes by damaged type were collected. As a result, it was found that the orders and values of weighted values of the divisions were different by damaged type: for example, soil property (0.402), vegetation growth & structure (0.209), habitat property (0.225), landscape structure & function (0.163) for "landform modification"; but soil property (0.171), vegetation growth & structure (0.401), habitat property (0.270), landscape structure & function (0.158) for "vegetation decline". Similarly, evaluation indexes showed different orders and values of relative importance, easiness in field measurement and representativeness for the division by damaged type, and the values were used for calculating importance factor for each index. In the evaluation table, score1 and score2 were made by the importance factors of indexes multiplied by distribution values which present grades and by the weighted values of divisions. In conclusion, while dealing with the damaged type was considered significant for evaluating and managing restorations, further tests on this table with a range of cases were needed to improve its quality.

발효기 하드웨어 변환을 이용한 용존산소 제어 (Feedback Control of Dissolved Oxygen with Hardware Modification of Fermenter)

  • 이중헌;이인영;박영훈
    • KSBB Journal
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    • 제15권3호
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    • pp.280-284
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    • 2000
  • The simple imcroprocessor device was provided for the control of dissolved oxygen(DO) level. The DO analog signal output from fementer was used as a measurement variable and the agitation speed of fermenter was used as a manipulatio variable. Agitation speed was manipulated to maintain DO level above 10% of saturation condition during cell growth period with microprocessor. Since the experimental resultsshowed that the DO level was maintained above 10% and agitation speed was inverse proportional to DO level ithis simple control device can be used for the DO control of fermenter.

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In situ growth of Mg-Al hydrotalcite film on AZ31 Mg alloy

  • Song, Yingwei;Chen, Jun;Shan, Dayong;Han, En-Hou
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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    • pp.12-13
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    • 2012
  • An environmentally friendly method for in situ growth of Mg-Al hydrotalcite (HT) film on AZ31 magnesium alloy has been developed. The growth processes and corrosion resistance of the HT film were investigated. Then the HT film was surface modified by phytic acid solution to further improve the corrosion resistance. The film formation involves the dissolution of AZ31 substrate, adsorption of the ions from solution, nucleation of the precursor, followed by the dissolution of $Al^{3+}$, exchanging of $OH^-$ by $CO{_3}^{2-}$ and growth of the HT film. The HT film is very compact and acts as a barrier against $Cl^-$ attack in the early stage of corrosion, and then the surface of the film is dissolved gradually. This dense HT film can provide effective protection to the AZ31 alloy. The HT film with surface modification by phytic acid presents a self-healing feature and exhibits better corrosion resistance.

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Silymarin-Mediated Degradation of c-Myc Contributes to the Inhibition of Cell Proliferation in Human Colorectal Cancer Cells

  • Eo, Hyun Ji;Jeong, Jin Boo;Koo, Jin Suk;Jeong, Hyung Jin
    • 한국자원식물학회지
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    • 제30권3호
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    • pp.265-271
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    • 2017
  • In this study, we elucidated the molecular mechanism of silymarin by which silymarin may inhibits cell proliferation in human colorectal cancer cells in order to search the new potential anti-cancer target associated with the cell growth arrest. Silymarin reduced the level of c-Myc protein but not mRNA level indicating that silymarin-mediated downregulation of c-Myc may result from the proteasomal degradation. In the confirmation of silymarin-mediated c-Myc degradation, MG132 as a proteasome inhibitor attenuated c-Myc degradation by silymarin. In addition, silymarin phosphorylated the threonine-58 (Thr58) of c-Myc and the point mutation of Thr58 to alanine blocked its degradation by silymarin, which indicates that Thr58 phosphorylation may be an important modification for silymarin-mediated c-Myc degradation. We observed that the inhibition of ERK1/2, p38 and $GSK3{\beta}$ blocked the Thr58 phosphorylation and subsequent c-Myc degradation by silymarin. Finally, the point mutation of Thr58 to alanine attenuated silymarin-mediated inhibition of the cell growth. The results suggest that silymarin induces the cell growth arrest through c-Myc proteasomal degradation via ERK1/2, p38 and $GSK3{\beta}-dependent$ Thr58 phosphorylation.

Cell Adhesion and Growth on Nanostructured Surface

  • Yoon, Seo Young;Park, Yi-Seul;Choi, Sung-Eun;Jung, Da Hee;Lee, Jin Seok
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.93-93
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    • 2013
  • To make the rationale design of interface between cell and artificial surface, many studies have been controlled influencing cue which can typically be divided into two central categories: chemical cues based on modification surface chemical properties containing attractive/repulsive molecules, and physical cues that may include applied tension/stress, electrical polarization, magnetic field, and topography. Recently, researches have been focused on physical cue, especially topography. The surface topography may influence cellular responses for example, cell adhesion, cell morphology and gene expression. However, there were few systematic studies about these nanotopographical effects on neuronal developments in a feature size-dependent manner. Herein, we report a nanoscale-resolved study of nanotopographical effects on cellular adhesion and growth. In this study, we use substrates with packed glass beads by rubbing method for generating highly periodic nanotopographies with various sizes. We found that acceleration of neuritogenesis appeared only on the beads larger than 200 nm in diameter, and observed that filopodial thickness was comparable with this scale. This study is expected to be essential to elucidate the nanotopographical effect on cellular adhesion and growth.

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Chemistry and Biology of Ras Farnesyltransferase

  • Cho, Kwang-Nym;Lee, Kee-In
    • Archives of Pharmacal Research
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    • 제25권6호
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    • pp.759-769
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    • 2002
  • Mutated forms of ras are found in many human tumors and the rate of incidence is significantly higher in colon and pancreatic cancers. The protein product from the ras oncogene is a small G-protein, $p21^{ras}{\;}(Ras)$ that is known to playa key role in the signal transduction cascade and cell differentiation and proliferation. Mutated Ras is unable to regulate itself and remains constantly activated, leading to uncontrolled cell growth. The function of Ras in signal transduction requires its location near the growth factor receptor at the cell membrane. However, Ras does not have a transmembrane domain. Ras requires farnesylation to increase its hydrophobicity and subsequent plasma membrane association for its transforming activity. This key post-translational modification is catalyzed by the enzyme Ras farnesyltransferase (FTase), which transfers a farnesyl group from farnesylpyrophosphate to the C-terminal cysteine of the Ras protein. The requirement has focused attention on FTase as a target for therapeutic intervention. Selective inhibition of FTase will prevent Ras protein from association with the plasma membrane, leading to a disruption of oncogenic Ras function.

열화학기상증착법에 의한 고순도 탄소나노튜브의 성장 (Growth of Highly Purified Carbon Nanotubes by Thermal Chemical Vapor Deposition)

  • 유재근;박정훈;김대운;이철진;손권희;신동혁;문인기
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권12호
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    • pp.649-653
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    • 2000
  • We have grown carbon nanotubes by thermal chemical vapor deposition of $C_{2}H_{2}$ on catalytic metal deposited on silicon oxide substrates. Highly purified carbon nanotubes are uniformly grown on a large area of the silicon oxide substrates. It is observed that surface modification of catalytic metals deposited on substrates by either etching with dipping in a HF solution and/or $NH_{3}$ pretreatment is a crucial step for the nanotube growth prior to the reaction of $C_{2}H_{2}$ gas. The diameters of carbon naotubes could be controlled by applying the different catalytic metals.

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Role of Energy and Composition of Film-Forming Species in Formation of Composition and Structure of Compound Films

  • Shaginyan, L.R.
    • 한국표면공학회지
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    • 제34권5호
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    • pp.455-464
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    • 2001
  • Effect of bombardment of the growing film by energetic particles on its properties is know over many years and is widely used for modification of the film properties. Despite of this there are no final answers on such questions as: what is the mechanism of compositional changes that take place for some compound films deposited under the ion bombardment, how the ion bombardment influences the epitaxial growth, what mechanisms govern the growth of the film on its early stages during deposition under the ion bombardment. The role of composition of film-forming species in formation of film structure is barely investigated or even not investigated at all. Experimental evidence and discussion of the influence of ion bombardment and composition of film-forming species on structure and composition of compound films are briefly considered in the review.

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층상구조의 염기성 zinc p-toluenesulfonate의 합성 및 성질에 관한 연구 (Synthesis and characterization of layered basic zine p-toluenesulfonates)

  • 김형동;조영식;허영덕
    • 한국결정성장학회지
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    • 제8권4호
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    • pp.651-654
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    • 1998
  • 층상구조의 염기성 zine p-toluenesulfonates를 표면변형법으로 직접 합성하였다. CHNS와 TG-DTA를 통해서 화합물의 화학적 조성을 결정하였다. X-선 회절 테이타와 분자의 크기로부터 수산화 아연층에 결합된 p-toluenesulfonate의 공간배열을 확인한 결과 p-toluenesulfonate의 분자 평면은 수산화아연층에 수직되게 결합하고 있음을 확인하였다.

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초박막구조 단결정성장을 위한 수직형 LPE장치의 제작과 성능개선에 관한 연구 (A Study on the Development & Performance Improvement of Vertical Type LPE System for a Ulta Thin Layer Single Crystal Growth)

  • 오종환;홍창희
    • 한국항해학회지
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    • 제19권4호
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    • pp.83-92
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    • 1995
  • In this study, a vertical type LPE system has been developed for III-V semiconductor compounds single crystal growth. On the basis of the experience & basic study using this system, the system modification has been carried out for a ultra thin multi-layer single crystal. The temperature fluctuation was within ${\pm}0.006^{\circ}C$ at $800^{\circ}C$, temperature uniformity for graphite boat around was within ${\pm}0.15^{\circ}C$ at $650^{\circ}C$, and cooling rate was controllable from $2.2^{\circ}C$/min to $0.05^{\circ}C$/min. As a result it is considered to satisfy the condition to grow a ultra thin layer single crystal of III-V semiconductor compounds.

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