• 제목/요약/키워드: NEM

검색결과 105건 처리시간 0.034초

SiC M/NEMS 연구개발 현황

  • 정귀상
    • 전력전자학회지
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    • 제14권1호
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    • pp.26-33
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    • 2009
  • 광대역 반도체중에서도 SiC(Silicon Carbide)는 우수한 전기적, 기계적, 열적, 화학적, 광학적 그리고 생체 적합성 등으로 인하여 지난 반세기 동안 급속히 발전하고 있는 SiM/NEMS(Micro/Nano Electro Mechanical System)를 대처할 수 있는 차세대 M/NEMS로써 고온, 고압, 고진동, 고습도 등의 극한 환경에서도 사용 가능한 자동차, 선박, 우주항공, 산업 프랜트용 마이크로 센서 및 액츄에이터, 초고주파수 정보통신용 부품 그리고 바이오 센서 등의 분야에 크게 주목을 받고 있다. 본 논문에서는 현재 SiC M/NEMS의 연구개발 현황에 대해서 소개하고자 한다.

Arachidonic Acid Liberated through Activation of $iPLA_2$ Mediates the Production of Reactive Oxygen Species and Apoptosis Induced by N-Ethylmaleimide in HepG2 Human Hepatoma Cells

  • Lee, Yong-Soo
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.242.2-243
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    • 2002
  • We have previously reported that activation of $K^{+}$-$Cl^{-}$-cotransport (KCC) by N-ethylmaleimide (NEM) induces apoptosis through generation of reactive oxygen species (ROS) in HepG2 human hepatoblastoma cells. In this study we investigated the possible role of phospholipase $A_2$($PLA_2$)-arachidonic acid (AA) signals in the mechanism of the NEM actions. (omitted)

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Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Stoenescu, D.;Lamarque-Forget, S.;Joly, S.;Dubois, J.C.;Martinot-Lagarde, Ph.;Dozov, I.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.97-100
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    • 2005
  • The recent Bistable Nematic ($BiNem{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing and high optical quality. The BiNem device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.

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In vitro Characterization of Bacteriocin Produced by Lactic Acid Bacteria Isolated from Nem Chua, a Traditional Vietnamese Fermented Pork

  • Pilasombut, Komkhae;Rumjuankiat, Kittaporn;Ngamyeesoon, Nualphan;Duy, Le Nguyen Doan
    • 한국축산식품학회지
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    • 제35권4호
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    • pp.473-478
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    • 2015
  • The aim of this study was to screen and In vitro characterize the properties of bacteriocin produced by lactic acid bacteria isolated from Vietnamese fermented pork (Nem chua). One hundred and fifty LAB were isolated from ten samples of Nem chua and screened for bacteriocin-producing lactic acid bacteria. Antimicrobial activity of bacteriocin was carried out by spot on lawn method against both gram positive and gram negative bacteria. One isolate, assigned as KL-1, produced bacteriocin and showed inhibitory activity against Lactobacillus sakei, Leuconostoc mesenteroides and Enterococcus faecalis. To characterize the bacteriocin-producing strain, optimum temperature, incubation period for maximum bacteriocin production and identification of bacteriocin-producing strain were determined. It was found that the optimum cultivation temperature of the strain to produce the maximum bacteriocin activity (12,800 AU/mL) was obtained at 30℃. Meanwhile, bacteriocin production at 6,400 AU/mL was found when culturing the strain at 37℃ and 42℃. The isolate KL-1 was identified as L. plantarum. Antimicrobial activity of cell-free supernatant was completely inhibited by proteolytic enzyme of trypsin, alpha-chymotrypsin and proteinase K. Bacteriocin activity was stable at high temperature up to 100℃ for 10 min and at 4℃ storage for 2 d. However, the longer heating at 100℃ and 4℃ storage, its activity was reduced.

파종기와 예취시기가 답리작 호밀의 동료가치에 미치는 영향 (Effects of Sowing Date and Cutting Time on Feed Value of Rye in Paddy Field)

  • 김창호;채제천
    • 한국작물학회지
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    • 제39권6호
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    • pp.519-525
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    • 1994
  • 충남 예산지방에서 호밀을 답리작으로 재배할 때 파종시기와 채취시기가 사요가치에 미치는 영향을 요약하면 다음과 같다. 1. 호밀의 조단백질, 가소화단백질, 총가소화양분(TDN)과 P, K, Ca, Mg 등의 무기물 그리고 에너지추정값(ENE), 필유에너지(NEL), 유지에너지(NEM), 증체에너지(NEG) 등의 에너지 함량은 파종기가 빠를수록 감소하고 ADF (acid detergent fiber) 와 NDF(neutral detergent fiber)는 증가하였다. 2. 단위면적당 조단백질, 가소화단백질, 총가소화양분(TDN), P, K, Ca, Mg등의 무기물 및 에너지추정값(ENE), 필유에너지(NEL), 유지에너지(NEM), 증체에너지(NEG) 등의 에너지 수량은 파종기가 빠를수록 증가하였으며 10월 5일에서 10월 25일까지의 파종기간에는 별 차이가 없었다. 3. 채취시기별로는 모든 파종기에서 조단백질은 개화후기 예취시, 가소화단백질 및 증체에너지 (NEG)는 출수기 예취시, 총가소화양분(TDN) 수량은 유숙기 예취시 제일 많았다. 4. 호밀의 채취적기는 관행사료가치 관점에서는 유숙기 무렵으로 판단되나 가소화단백질 및 증체에너지(NEG)측면에서는 출수기 무렵이 적기로 판단되었다.

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아라비돕시스 탈리아나 Acetolactate Synthase의 화학적 변형과 되먹임 방해 (Chemical Modification and Feedback Inhibition of Arabidopsis thaliana Acetolactate Synthase)

  • 홍성택;최명언;신정휴;고은희
    • Applied Biological Chemistry
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    • 제40권4호
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    • pp.277-282
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    • 1997
  • 아라비돕시스 탈리아나의 아세토락테이트 합성 효소 (ALS)를 그 유전자를 포함하고 있는 대장균 MF 2000/pTATX로부터 부분 정제하였다. 부분 정제된 이 효소를 가지고 여러 가지 변형 화학물질들 즉, 요오드아세트산, 요오드아세타마이드, N-에틸말레이미드 (NEM), 5,5'-디티오비스(2-니트로벤조산) (DTNB), 파라염화수은벤조산 (PCMB), 그리고 페닐글리옥살 등에 대한 민감성을 조사하였다. PCMB가 가장 민감하게 저해를 했으며, DTNB와 NEM이 그 뒤를 따랐다. 이 효소의 기질인 피루브산이 요오드아세트산에 의한 활성 저해를 보호하지 못하였으므로 기질의 결합에 시스테인의 관련이 없는 것 같이 보인다. 한편, 기질이 페닐글리옥살에 의한 효소의 활성 저해를 부분적으로 보호하는 것으로 보아 기질이 아르기닌기와 상호 작용함을 암시하고 있다. 부분 정제된 효소는 발린과 이소루신에 민감하게 방해를 받았으나 루신은 그렇지 않았다. 그러나, PCMB로 변형시킨 효소는 되먹임 방해를 더 강하게 받았다. 그 외 ALS에 대한 새로운 제초제 후보인 피리미디설퍼 벤조산 유도체의 저해 효과를 검토하였다.

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Arachidonic Acid Activates $K^+$-$Cl^-$-cotransport in HepG2 Human Hepatoblastoma Cells

  • Lee, Yong-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • 제13권5호
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    • pp.401-408
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    • 2009
  • $K^+$-$Cl^-$-cotransport (KCC) has been reported to have various cellular functions, including proliferation and apoptosis of human cancer cells. However, the signal transduction pathways that control the activity of KCC are currently not well understood. In this study we investigated the possible role of phospholipase $A_2$ ($PLA_2$)-arachidonic acid (AA) signal in the regulatory mechanism of KCC activity. Exogenous application of AA significantly induced $K^+$ efflux in a dose-dependent manner, which was completely blocked by R-(+)-[2-n-butyl-6,7 -dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-1Hinden-5-yl]oxy]acetic acid (DIOA), a specific KCC inhibitor. N-Ethylmaleimide (NEM), a KCC activatorinduced $K^+$ efflux was significantly suppressed by bromoenol lactone (BEL), an inhibitor of the calciumindependent $PLA_2$ ($iPLA_2$), whereas it was not significantly altered by arachidonyl trifluoromethylketone ($AACOCF_3$) and p-bromophenacyl bromide (BPB), inhibitors of the calcium-dependent cytosolic $PLA_2$ ($cPLA_2$) and the secretory $PLA_2$ ($sPLA_2$), respectively. NEM increased AA liberation in a doseand time-dependent manner, which was markedly prevented only by BEL. In addition, the NEM-induced ROS generation was significantly reduced by DPI and BEL, whereas $AACOCF_3$ and BPB did not have an influence. The NEM-induced KCC activation and ROS production was not significantly affected by treatment with indomethacin (Indo) and nordihydroguaiaretic acid (NDGA), selective inhibitors of cyclooxygenase (COX) and lipoxygenase (LOX), respectively. Treatment with 5,8,11,14-eicosatetraynoic acid (ETYA), a non-metabolizable analogue of AA, markedly produced ROS and activated the KCC. Collectively, these results suggest that $iPLA_2$-AA signal may be essentially involved in the mechanism of ROS-mediated KCC activation in HepG2 cells.

Excretory-secretory product of Paragonimus westermani newly excysted metacercariae inhibits superoxide production of granulocytes stimulated with IgG

  • Shin, Myeong-Heon
    • Parasites, Hosts and Diseases
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    • 제38권2호
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    • pp.103-106
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    • 2000
  • It is well known that the cysteine proteases in excretory-secretory product (ESP) of Paragonimus westermani newly excysted metacercariae (PwNEM) are capable of degrading IgG in vitro. Recent evidence suggests that the IgG-coated surface, such as found on parasites, is one of the most effective physiologic stimuli for granulocyte activation. Therefore, this study was designed to investigate the effect of excretory-secretory product (ESP) of PwNEM on superoxide production of granulocytes stimulated with IgG The 96-well plates were coated with human IgG (0, 10, 30, $100{\;}\mu\textrm{g}/ml$) in the absence or presence of ESP. When granulocytes were incubated in the wells coated with human IgG in the presence of ESP, the level of superoxide production of granulocytes was reduced to about 90% when compared to the cells incubated in the wells coated with IgG alone. This inhibitory effect of the ESP on IgG-induced superoxide production of granulocytes was concentration-dependent. These results suggest that ESP secreted by PwNEM may be important in the control of effector functions of granulocytes stimulated with IgG in human paragonimiasis.

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PREVENTION OF HYDROXYL RADICAL-INDUCED ERYTHROCYTE HEMOLYSIS BY PROTEIN THIOLS

  • Youn, Hong-Duk;Packer, Lester;Matsugo, Seiichi
    • Journal of Photoscience
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    • 제4권3호
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    • pp.133-140
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    • 1997
  • A system for studying oxidative hemolysis has been used by controling UV-irradiation and concentration of a novel molecular probe, N,N'-bis(2-hydroperoxy-2-methoxyethyl)-1,4,5,8-naphthalenetetra-carboxylic diimide (NP-III), which generates hydroxyl radical upon longer wavelength photoirradiation (> 350 nm). NP-III induces 25~30% of hemolysis at low concentration (50 $\mu$M) for 3h-irradiation of UVA. The simultaneous treatment of N-ethylmaleimide (NEM) with NP-IH completely hemotyzed erythrocytes under the same conditions as NP-III alone by both decreasing thiol group and increasing lipid peroxidation in erythrocyte membrane. However. thiol-reducing agents prevented the protein-crosslinking and lipid peroxidation on the NEM-synergistic hemolysis by partially scavenging hydroxyl radical and maintaining the thiol group of erythrocyte membrane in the reduced state. In addition, erythrocytes pretreated with 2,2,5,7,8-pentamethyl-6-hydroxychromane (PMC), vitamin E homologue was able to delay and decrease the lipid peroxidation when compared to cells pretreated with both NEM and PMC. We suggest that the presence of reduced thiols in inner membrane protein by GSH can prevent the protein-crosslinking and the lipid peroxidation, and eventually prevent the oxidative hemolysis of erythrocyte.

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One-node and two-node hybrid coarse-mesh finite difference algorithm for efficient pin-by-pin core calculation

  • Song, Seongho;Yu, Hwanyeal;Kim, Yonghee
    • Nuclear Engineering and Technology
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    • 제50권3호
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    • pp.327-339
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    • 2018
  • This article presents a new global-local hybrid coarse-mesh finite difference (HCMFD) method for efficient parallel calculation of pin-by-pin heterogeneous core analysis. In the HCMFD method, the one-node coarse-mesh finite difference (CMFD) scheme is combined with a nodal expansion method (NEM)-based two-node CMFD method in a nonlinear way. In the global-local HCMFD algorithm, the global problem is a coarse-mesh eigenvalue problem, whereas the local problems are fixed source problems with boundary conditions of incoming partial current, and they can be solved in parallel. The global problem is formulated by one-node CMFD, in which two correction factors on an interface are introduced to preserve both the surface-average flux and the net current. Meanwhile, for accurate and efficient pin-wise core analysis, the local problem is solved by the conventional NEM-based two-node CMFD method. We investigated the numerical characteristics of the HCMFD method for a few benchmark problems and compared them with the conventional two-node NEM-based CMFD algorithm. In this study, the HCMFD algorithm was also parallelized with the OpenMP parallel interface, and its numerical performances were evaluated for several benchmarks.