• 제목/요약/키워드: 김대식

검색결과 833건 처리시간 0.029초

마우스대식세포주인 RAW 264.7에서 금령자산(金鈴子散)(金鈴子散)의 항염증 활성 연구 (Anti-inflammatory effect of methanol extract of Keum-Ryung-Ja-San in mouse macrophages)

  • 김도형;이효승;윤현정;차창민;박선동
    • 대한본초학회지
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    • 제25권2호
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    • pp.89-98
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    • 2010
  • Objective : The aim of this study was to determine whether methanol extract of Keum-Ryung-Ja-San (KRJS) inhibit production of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Methods : Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The nitric oxide (NO) production was measured by Griess reagent system. And proinflammatory cytokines and PGE2 were measured by ELISA kit. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2(COX-2), $I{\kappa}-B-\alpha$ and nuclear NF-${\kappa}B$ p65 expression were detected by western blot. Results : Our results indicated that methanol extract of KRJS significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-$\alpha$, IL-$1{\beta}$ and IL-6 production in RAW 264.7 cells. Moreover, methanol extract of KRJS treatment also blocked LPS-induced NF-${\kappa}B$ activation. Conclusion : These findings indicate that methanol extract of KRJS inhibits the production of pro-inflammatory mediators and cytokines via suppression of NF-${\kappa}B$ activation. Take together, these results indicate that methanol extract of KRJS has the potential for use as an agent of anti-chronic inflammatory diseases.

LPS로 유도된 대식세포 활성에서 발효 산약 추출물의 억제 효과 (The Inhibitory Effect of Fermented Dioscoreae batatas Extract on Lipopolysaccharide-induced Macrophage Activation)

  • 임성원;이선희;허정무;이영미;김대기
    • 약학회지
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    • 제55권5호
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    • pp.404-410
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    • 2011
  • This study was to elucidate the anti-inflammatory activities of a methanol extract derived from the fermented bark of Dioscoreae batatas on LPS-induced activation in macrophages. It was fermented with Lactobacillus fermentum and L. plantarum and then analyzed to identify the contents of methanol extract and diosgenin. The fermented product showed 3-fold increase in the extraction yield by methanol, and 1.8-fold increase in diosgenin contents, compared to that from the dried bark of D. batatas. Although the methanol extract from the unfermented D. batatas inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and TNF-${\alpha}$ in J774 A.1 cells, the methanol extract from the fermented product revealed significantly the enhanced the inhibitory activities on LPS-induced production of NO and TNF-${\alpha}$. Taken together, our results indicate that fermentation of bark of D. batatas elevates the functional activity inhibiting macrophage activation through the increase of the content of anti-inflammatory compounds. Thus, its methanol extract may be useful as a functional material for the therapy of inflammatory diseases.

이온빔 배향에 의한 수직 배향막의 액정 배향 (Vertical Alignment of Liquid Crystal by Ion Beam Irradiation)

  • 강동훈;김병용;김영환;옥철호;한정민;김종환;이상극;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.414-414
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    • 2007
  • In this study, Liquid Crystal (LC) alignment and tilt angle generation in Nematic Liquid Crystal (NLC) with negative dielectric anisotropy on the homeotropic PI surface with new ion beam exposure are reported. Also. high density of ion beam energy (DuoPIGatron type Ar ion gun) is used in this study. The tilt angle of NLC on the homeotropic Polyimide (PI) surface for all incident angles is measured about 38 degree and this has a stabilization trend. And the good LC alignment of NLC on the PI surface with ion beam exposure of $45^{\circ}$ incident angle was observed. Also the tilt angle of NLC on the homeotropic PI surface with ion beam exposure of $45^{\circ}$ had a tendency to decrease as ion beam energy density increase. The tilt angle could be controlled from verticality to horizontality. Also, the LC aligning capabilities of NLC on the homeotropic PI surface according to ion beam energy has the goodness in case of more than 1500 eV. Finally. the superior LC alignment thermal stability on the homeotropic PI surface with ion beam exposure can be achieved. For OCB(Optically Compensated Bend) mode driving, we can need pretilt angles control for fast response time. In this study, We success pretilt angles control. Consequently, this result can be applied for OCB mode.

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이온빔 조사 각도와 에너지강도에 의한 수직 배향막의 특성 분석 (Characteristic Analysis of Vertical Alignment by Ion-beam Irradiation Angle and Energy Density)

  • 강동훈;오병윤;김병용;한진우;김영환;옥철호;한정민;이상극;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.398-398
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    • 2007
  • The Liquid Crystal (LC) alignment uniformity is very important in LC devices. The alignment mechanism of LC molecules on a rubbed polyimide (PI) surface is very important for both LC fundamental research and application. So, Generally a rubbing method to align LC has been widely used to mass-produce LCD panels. But because rubbing method is contact method between rubbing fabric and indium-tin-oxide glass or flexible substrate, rubbing method has some defects, such as the electrode charges and the creation of contaminating particles. Thus we strongly recommend a non-contact alignment technique for getting rid of some defects of rubbing method. Most recently, the LC aligning capabilities achieved by ion-beam exposure on the organic and nonorganic thin film surface have been reported successfully. In this research, we studied the tilt angle generation and electro-optical performances for a NLC on homeotropic polyimide surfaces with ion-beam exposure. The LC aligning capabilities of a nematic liquid crystal (NLC) on a homeotropic PI surface using a new ion-beam method were studied. On the homeotropic PI surface, the tilt angle of the NLC by exposure ion-beam had a tendency to decrease as increased ion-beam energy density. And, on the homeotropic PI surface, the alignment character of the NLC with respect to ion-beam energy was good. And we achieved satisfactory result for EO character.

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이온빔 에너지와 유기절연막 사용에 의한 액정 배향 연구 (Investigation of LC Alignment Using Ion-beam and Overcoat Layer)

  • 김병용;박홍규;이강민;오병윤;강동훈;한진우;김영환;한정민;김종환;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.370-370
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    • 2007
  • The liquid crystal (LC) aligning capabilities treated on the Organic overcoat thin film surfaces by ion beam irradiation and rubbing method was successfully studied for the first time. The Organic overcoat layer was coated by spin-coating. In order to characterize the LC alignment, the microscope, pretilt angle, thermal stress, and atomic force microscopy (AFM) image was used. The good LC aligning capabilities treated on the Organic overcoat thin film surfaces with ion beam exposure of $45^{\circ}$ above ion beam energy density of 1200 eV can be achieved. But, the alignment of defect of NLC on the Organicovercoat surface at low energy density of 600 eV was measured. The pretilt angle of NLC on the Organic overcoat thin film surface with ion beam exposure of $45^{\circ}$ for 1 min at energy density of 1800eV was measured about 1.13 degree. But, low pretilt angles of NLC on the Organic overcoat thin film surface with ion beam exposure at energy density of 600, 1200, 2400, and 3000 eV was measured. Also, the pretilt angle of NLC on the rubbed Organic overcoat thin film surfaces was measured about 0.04 degrees. Finally, the good thermal stability of LC alignment on the Organic overcoat thin film surface with ion beam exposure of $45^{\circ}$ for 1 min can be measured.

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고분자 기판위에 유기 용매를 사용하지 않은 다층 박막 Encapsulation 기술 개발 (Improvement of Permeation of Solvent-free Multi-Layer Encapsulation of thin films on Ethylene Terephthalate(PET))

  • 강희진;한진우;김종연;문현찬;최성호;박광범;김태하;김휘운;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 학술대회 및 기술세미나 논문집 디스플레이 광소자
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    • pp.56-57
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    • 2006
  • In this paper, the inorganic multi-layer thin film encapsulation was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter, inorganic multi-layer thin-film encapsulation was deposited onto the Ethylene Terephthalate(PET) and their interface properties between inorganic and organic layer were investigated. In this investigation, the SiON SiO2 and parylene layer showed the most suitable properties. Under these conditions, the WVTR for PET can be reduced from a level of $0.57\;g/m^2/day$ (bare subtrate) to 1*10-5 g/$m^2$/day after application of a SiON and SiO2 layer. These results indicates that the PET/SiO2/SiON/Parylene barrier coatings have high potential for flexible organic light-emitting diode(OLED) applications.

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P3HT와 IZO 전극을 이용한 thin film transistors 제작 (Fabricated thin-film transistors with P3HT channel and $NiO_x$ electrodes)

  • 강희진;한진우;김종연;문현찬;박광범;김태하;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.467-468
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    • 2006
  • We report on the fabrication of P3HT-based thin-film transistors (TFT) that consist of indium-zinc-oxide (IZO), PVP (poly-vinyl phenol), and Ni for the source-drain (S/D) electrode, gate dielectric, and gate electrode, respectively. The IZO S/D electrodes of which the work function is well matched to that of P3HT were deposited on a P3HT channel by thermal evaporation of IZO and showed a moderately low but still effective transmittance of ~25% in the visible range along with a good sheet resistance of ${\sim}60{\Omega}/{\square}$. The maximum saturation current of our P3HT-based TFT was about $15{\mu}A$ at a gate bias of -40V showing a high field effect mobility of $0.05cm^2/Vs$ in the dark, and the on/off current ratio of our TFT was about $5{\times}10^5$. It is concluded that jointly adopting IZO for the S/D electrode and PVP for gate dielectric realizes a high-quality P3HT-based TFT.

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이온 빔 조사된 SiNx 박막의 액정 배향 효과에 관한 연구 (Investigation on Liquid Crystal Alignment Effects of SiNx Thin Film Irradiated by Ion Beam)

  • 이상극;김영환;김병용;한진우;강동훈;김종환;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.398-398
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    • 2007
  • Most recently, the Liquid Crystal (LC) aligning capabilities achieved by ion beam exposure on the diamond-like carbon (DLC) thin film layer have been successfully studied. The DLC thin films have a high mechanical hardness, a high electrical resistance, optical transparency and chemical inertness. Nitrogen doped Diamond Like Carbon (NDLC) thin films exhibit properties similar to those of the DLC films and better thermal stability than the DLC films because C:N bonding in the NDLC film is stronger against thermal stress than C:H bonding in the DLC thin films. Moreover, our research group has already studied ion beam alignment method using the NDLC thin films. The nematic liquid crystal (NLC) alignment effects treated on the SiNx thin film layers using ion beam irradiation for three kinds of N rations was successfully studied for the first time. The SiNx thin film was deposited by plasma-enhanced chemical vapor deposition (PECVD) and used three kinds of N rations. In order to characterize the films, the atomic force microscopy (AFM) image was observed. The good LC aligning capabilities treated on the SiNx thin film with ion beam exposure for all N rations can be achieved. The low pretilt angles for a NLC treated on the SiNx thin film with ion beam irradiation were measure.

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GaMnAs의 Be 병행 도핑에 의한 자기 수송 특성 연구 (Magnetotransport of Be-doped GaMnAs)

  • 임완순;윤대식;우부성;고존서;김도진;임영언;김효진;김창수;김종오
    • 한국재료학회지
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    • 제15권1호
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    • pp.73-77
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    • 2005
  • Motivated by the enhanced magnetic properties of Mg-codoped GaMnN ferromagnetic semiconductors, Be-codoped GaMnAs films were grown via molecular beam epitaxy with varying Mn flux at a fixed Be flux. The structural, electrical, and magnetic properties were investigated. GaAs:(Mn,Be) films showed metallic behavior while GaAs:Mn films showed semiconducting behavior as determined by the temperature dependent resistivity measurements. The Hall-effect measurements with varying magnetic field showed clear anomalous Hall effect up to room temperature proving ferromagnetism and magnetotransport in the GaAs:(Mn,Be) films. Planar Hall resistance measurement also confirmed the properties. The dramatic enhancement of the Curie temperature in GaMnAs system was attributed to Be codoping in the GaMnAs films as well as MnAs precipitation.

열전도성 플라스틱을 이용한 김치냉장고용 열교환기에 관한 연구 (Research on the Heat Exchanger for Kimchi Refrigerator Using Thermal Conductive Plastic)

  • 강태호;백정용;권용하;김인관;김영수;신대식;박재홍
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권4호
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    • pp.407-416
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    • 2005
  • The kimchi refrigerator is the electric home appliance which is used for the maturing and preserving of the kimchi in domestic and foreign market. The kimchi refrigerator is composed in 3 main parts as insulation. kimchi container, machinery room. The heat exchanger of kimchi refrigerator is made of aluminum and the other parts are made of steel and polymer. Also, kimchi refrigerator is expensive and heavy as compared with same class of refrigerator until now. In the present study, the possibility to replace heat exchanger from aluminum to thermal conductive plastic was analyzed and experimented. The thermal conductive plastic has $10{\sim}100$ times heat conductivity than that of normal plastic. It is known that heat transfer process is dependent not only conduction but convection or radiation. Thermal conductivity of the applied material in this research is over than 2 W/mK, thermal conductivity doesn't play a vital role on heat transfer. In this study, temperature is the most important parameter on the kimchi refrigerator and the temperature of kimchi refrigerator's heat exchanger was measured and compared with the temperature calibrated by CFD analysis on the inside wall of the kimchi refrigerator. It is important to keep constantly the inside temperature of the Kimchi refrigerator. Besides numerical analyses for the new thermal conductive plastic for heat exchanger were executed with the various height of evaporation tube. A series of experiments were conducted to compare the performance of the two heat exchanger made of aluminum and thermal conductive plastic at the same condition and certified the possibility of the thermal conductive plastic. According to these results, it was confirmed that the conventional aluminium heat exchanger can be replaced by thermal conductive plastic successfully.