• 제목/요약/키워드: Native Oxide

검색결과 145건 처리시간 0.024초

Anti-inflammatory Effect of Dangyuja (Citrus grandis Osbeck) Leaves in LPS-stimulated RAW 264.7 Cells

  • Yang, Eun-Jin;Lee, Hye-Ja;Kang, Gyeoung-Jin;Park, Sun-Soon;Yoon, Weon-Jong;Kang, Hee-Kyoung;Cho, So-Mi Kim;Yoo, Eun-Sook
    • Food Science and Biotechnology
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    • 제18권5호
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    • pp.1063-1070
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    • 2009
  • Dangyuja (Citrus grandis Osbeck) is a native plant growing only on Jeju Island in Korea. In this study, antiinflammatory effect of dangyuja leaves on a murine macrophage cell line was investigated. RAW 264.7 murine macrophage cells were stimulated with lipopolysaccharide (LPS, $1{\mu}g/mL$) to induce expression of pro-inflammatory markers [interleukin (IL)-6 and inducible nitric oxide synthase (iNOS)]. The crude extract (80% MeOH Ex.) and solvent fractions (hexane, $CHCl_3$, EtOAc, BuOH, and $H_2O$ Ex.) were obtained from dangyuja leaves. The $CHCl_3$ fraction inhibited the nitric oxide (NO) and IL-6 production in a dose-dependent manner. Also, the $CHCl_3$ fraction inhibited mRNA expression and protein levels of iNOS in a dose-dependent manner. Furthermore, the $CHCl_3$ fraction inhibited LPS-induced nuclear factor (NF)-${\kappa}B$ activation and phosphorylation of mitogen-activated protein kinases (MAPKs: ERK, JNK, and p38). These results suggest that dangyuja leaves may inhibit LPS-induced production of inflammatory markers by blocking NF-${\kappa}B$ and MAPKs signaling in RAW 264.7 cells.

살구의 휘발성 성분 조성에 대한 분리방법의 영향 (Influence of Isolation Method on the Composition of Apricot (Prunus armeniaca var. ansu Max.) Flavor)

  • 김영회;곽재진;권영주;양광규
    • 한국식품과학회지
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    • 제22권5호
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    • pp.543-548
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    • 1990
  • 살구의 휘발성 향기성분 조성에 대한 분리 방법의 영향을 조사코저 살구 과육(pH 3.1)을 simultaneous distillation-extraction(SDE)법, headspace trapping법 또는 이를 pH 7.0으로 중화시킨 후 SDE법에 의해 얻어진 정유성분의 조성을 분석 비교하였다. GC-MS 및 GC에 의한 표준품과 머무름 시간의 비교에 의해 확인된 80종의 성분들 중 pH3.1에서 SDE법에 의해 얻어진 정유성분중에는 다른 두 가지 방법에 의해 얻어진 정유성분에서는 검출되지 않거나 또는 미량으로 검출된 n-hexanal, trans-2-hexenal, cis-3-hexen-1-ol, linalool oxide, linalool, ${\alpha}-terpineol$, nerol, geraniol, benzyl alcohol, ${\beta}-phenylethyl alcohol$ 및 naphthalene 유도체들이 많이 검출되었으며 이러한 결과는 살구에서 비휘발성인 glycoside 형태로 존재하는 위와 같은 성분들이 산성조건하에서 수증기 증류시 glycoside 결합이 가수분해되어 휘발성 성분으로 유리되는데 기인하는 것으로 판단되었다.

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우울증완화의 효과적인 국내산 9종 식물 조합오일의 생리활성 효과 연구 (9 types of domestic plant combination oil effective for relieving depression Bioactive effect research)

  • 정숙희
    • 한국응용과학기술학회지
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    • 제40권1호
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    • pp.103-112
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    • 2023
  • 본 연구는 우울에 효과가 입증된 국내 자생 식물 9종(배초향, 적송, 강황, 생강, 산미나리씨, 불수감, 황칠, 탱자, 쥐오줌풀) 을 선정하여 각각의 향기 성분 분석결과를 기반으로 9종 정유를 조합하여 항산화(DPPH, ABTS), 세포독성(MTS), 항염(Nitric oxide)실험을 수행하였다. 향기성분 분석결과 조합오일에서 기연구된 우울완화 효과 성분인 DL-Limonene(38.44%), g-Terpinene(8.9%), Estragole(5.18%), a-Pinene(1.73%) 등이 동정되었다. 항산화 활성인 DPPH 라디칼 소거능은 75.4%, ABTS 라디칼 소거능은 74.04%을 보였으며, 세포독성이 확인되지 않은 5uL/ml의 농도에서 NO 생성 저해능은 33.14%로 나타났다. 이를 통하여 국내 블렌딩 정유의 우울증의 개선 또는 예방에 대한 효과를 검증하고 더불어 과학적 효능과 성분 연구가 상호 협력적으로 이루어져 우울증적 증상 개선 유무를 확인 할 수 있는 기초자료로 제공하고자 한다.

시호 추출물의 oxLDL 유도 Foam Cell 형성 억제 작용 (Inhibitory Effects of Bupleuri Radix on ox-LDL induced Foam Cell Formation)

  • 이혜진;배호성;황귀서
    • 대한예방한의학회지
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    • 제16권2호
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    • pp.113-124
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    • 2012
  • The oxidative modification of low density lipoprotein(LDL) has been implicated in the development of atherosclerosis. Oxidized LDL(oxLDL) is captured into macrophage and stimulates to form macrophage foam cell. And it can induce an inflammation and smooth muscle proliferation in atherosclerotic plaque. Objective : In this study, we aimed to investigate the effect of Bupleuri radix(SH) on the foam cell formation, a critical initiation stage of atherosclerosis. Methods : To achieve the goal, we examined the effect of SH on LDL oxidation, nitric oxide production in RAW264.7, and the effect of SH on cupuric sulfate-induced cytotoxicity, LDH release, and macrophage activity. Results : SH inhibited the formation of oxidized LDL from native LDL in RAW264.7 cell culture, and decreased the release of LDH from cupric sulfate-stimulated RAW264.7 cell. In other experiments, SH activated RAW264.7 cell, and prolonged the survival time, and inhibited foam cell formation induced by oxLDL in Raw 264.7 cells. Conclusion : These results showed that SH might prevent atherosclerosis by controlling the early stages of foam cell formation.

꽃향유 향미유의 개발 및 전자코를 이용한 향기패턴 분석 (Development of Elsholtzia splendens-Flavored Oils and Analysis of Flavor Pattern Using Electronic Nose)

  • 정미숙;이미순
    • 한국식품조리과학회지
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    • 제18권4호
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    • pp.455-460
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    • 2002
  • This experiment was conducted to obtain basic information on the natural spice of Elsholtzia splendens, which is one of the native Korean aromatic plants for aromatic, medicinal and ornamental uses. The overall acceptability and the masking effects on the fetid smell of beef were investigated with Elsholtzia splendens-flavored oils by sensory evaluation. The ability of an electronic nose with six metal oxide sensors to classify Elsholtzia splendens flavored oils based on their odors was studied. The response by electronic nose was analyzed by principal component analysis (PCA). In EOI, EOII, and ESI, (이것들이 무엇을 의미하는지 기술할 필요가 있음). overall acceptability of French dressing showed a same level of preference during storage. Fetid smell of beef was not changed by the addition of 4 types of Elsholtzia splendens-flavored oil during storage. In EO I -flavored oil, the proportion of 1st principal component was 0.829, and the proportion of 1st principal component was 0.818 in ESI-flavored oil. The PCA plot was used to detect stored Elsholtzia splendens flavored oils.(앞 뒤 문맥이 안맞음. 뒤에 이어지는 글이 있는지\ulcorner).

MBE로 성장한 $Si_{ l-x}Mn_x$ 박막의 전자기적 특성 연구 (Magneto-electronic Properties of $Si_{ l-x}Mn_x$ Thin Films Grown by MBE)

  • 김종환;유상수;김한겸;권당;조영미;임영언
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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    • pp.100-100
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    • 2003
  • 본 연구에서는 Si에 Mn을 첨가한 Si$_{l-x}$Mn$_{x}$ 박막의 전기적 및 자기적 특성을 조사하였다. Si$_{l-x}$Mn$_{x}$ 박막은 MBE(Molecular Beam Epitaxy)를 이용하여 native oxide층을 제거하지 않은 (100)Si wafer 위에 성장하였다. Substrate 온도는 50$0^{\circ}C$로 하였으며, 첨가한 Mn 농도는 20%에서부터 80%까지였다. 전기적 특성은 Hall, 4-point probe를 통하여 측정하였고, 자기적 특성은 VSM, FMR, SQUID을 이용하여 측정하였다. 상 분석은 XRD, TEM을 이용하여 관찰하였다 Si$_{l-x}$Mn$_{x}$ 박막은 Hall 측정 결과 상온에서 P-type carrier를 가지며, 비저항은 반도체 영역인 7.6$\times$$10^{-4}$~4.2$\times$$10^{-2}$(ohm-cm)의 값을 가진다. 상온 VSM, 측정결과 Mn의 양이 52% 첨가 시 포화 자화 값이 가장 높은 40emu/cc를 가지며, Mn의 양이 증가할수록 포화 자화 값이 증가하다 다시 감소하는 경향을 가진다. FMR, SQUID 측정에서도 이러한 경향을 확인할 수 있었다 특히, SQUID 분석 결과 두 개 이상의 자성 상이 존재하는 것을 관찰할 수 있었다. XRD, TEM 관찰결과, Si$_{l-x}$Mn$_{x}$은 poly crystal로 성장하였으며, Mn 농도에 따라 여러 상들이 관찰되었다.따라 여러 상들이 관찰되었다.

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PECVD 질화막 증착시 $SiH_4/NH_3$ 유량비가 비휘발성 MNOS 기억소자의 특성에 미치는 영향 (The Influence of the $SiH_4/NH_3$ Ratios on the Characteristics of Nonvolatile MNOS Memories during the PECVD Silicon Nitride Film deposition)

  • 이상배;이근혁;이형옥;김진영;서광열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 B
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    • pp.832-834
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    • 1992
  • Using the PECVD method, the silicon nitride films were deposited by changing the $SiH_4/NH_3$ gas flow ratio from 0.2 to 1.4 at an interval of 0.2, AES, FTIR, and Spectroscopic Ellipsomter were used to analyze the film composition and structure, the refractive index, and the deposition rate. Also the C-V analysis was used to estimate the memory performance in the capacitor type MNOS memory devices, which utilized native oxide as the tunneling barrier, with the silicon nitride by the above deposition conditions. As a result, it was confirmed that the performance of MNOS memory devices with PECVD silicon nitride was comparable to that with LPCVD or APCVD silion nitride.

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응력 및 표면 고장물리를 고려한 MEMS 신뢰성 설계 기술 (Reliability Design of MEMS based on the Physics of Failures by Stress & Surface Force)

  • 이학주;김정엽;이상주;최현주;김경식;김장현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1730-1733
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    • 2007
  • As semiconductor and MEMS devices become smaller, testing process during their production should follow such a high density trend. A circuit inspection tool "probe card" makes contact with electrode pads of the device under test (DUT). Nowadays, electrode pads are irregularly arranged and have height difference. In order to absorb variations in the heights of electrode pads and to generate contact loads, contact probes must have some levels of mechanical spring properties. Contact probes must also yield a force to break the surface native oxide layer or contamination layer on the electrodes to make electric contact. In this research, new vertical micro contact probe with bellows shape is developed to overcome shortage of prior work. Especially, novel bellows shape is used to reduce stress concentration in this design and stopper is used to change the stiffness of micro contact probe. Variable stiffness can be one solution to overcome the height difference of electrode pads.

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자연 산화막과 엑시머 레이저를 이용한 Poly-Si/a-Si 이중 박막 다결정 실리콘 박막 트랜지스터 (Poly-Si Thin Film Transistor with poly-Si/a-Si Double Active Layer Fabricated by Employing Native Oxide and Excimer Laser Annealing)

  • 박기찬;박진우;정상훈;한민구
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권1호
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    • pp.24-29
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    • 2000
  • We propose a simple method to control the crystallization depth of amorphous silicon (a-Si) deposited by PECVD or LPCVD during the excimer laser annealing (ELA). Employing the new method, we have formed poly-Si/a-Si double film and fabricated a new poly-Si TFT with vertical a-Si offsets between the poly-Si channel and the source/drain of TFT without any additional photo-lithography process. The maximum leakage current of the new poly-Si TFT decreased about 80% due to the highly resistive vertical a-Si offsets which reduce the peak electric field in drain depletion region and suppress electron-hole pair generation. In ON state, current flows spreading down through broad a-Si cross-section in the vertical a-Si offsets and the current density in the drain depletion region where large electric field is applied is reduced. The stability of poly-Si TFT has been improved noticeably by suppressing trap state generation in drain region which is caused by high current density and large electric field. For example, ON current of the new TFT decreased only 7% at a stress condition where ON current of conventional TFT decreased 89%.

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나노/마이크로 PDMS 채널 제작을 위한 마스크리스 실리콘 스템퍼 제작 및 레오로지 성형으로의 응용 (Maskless Fabrication of the Silicon Stamper for PDMS Nano/Micro Channel)

  • 윤성원;강충길
    • 소성∙가공
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    • 제13권4호
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    • pp.326-333
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    • 2004
  • The nanoprobe based on lithography, mainly represented by SPM based technologies, has been recognized as a potential application to fabricate the surface nanosctructures because of its operational versatility and simplicity. However, nanoprobe based on lithography itself is not suitable for mass production because it is time a consuming method and not economical for commercial applications. One solution is to fabricate a mold that will be used for mass production processes such as nanoimprint, PDMS casting, and others. The objective of this study is to fabricate the silicon stamper for PDMS casting process by a mastless fabrication technique using the combination of nano/micro machining by Nanoindenter XP and KOH wet etching. Effect of the Berkovich tip alignment on the deformation was investigated. Grooves were machined on a silicon surface, which has native oxide on it, by constant load scratch (CLS), and they were etched in KOH solutions to investigate chemical characteristics of the machined silicon surface. After the etching process, the convex structures was made because of the etch mask effect of the mechanically affected layer generated by nanoscratch. On the basis of this fact, some line patterns with convex structures were fabricated. Achieved groove and convex structures were used as a stamper for PDMS casting process.