• 제목/요약/키워드: Native oxide

검색결과 148건 처리시간 0.038초

가교화 후 하이드록시프로필화한 복합변성 쌀전분의 이화학적 특성 (Physiohemical Properties of Dual-Modified (Cross-linked and Hydroxypropylated) Rice Starches)

  • 최현욱;홍사훈;최성원;김창남;유승석;김병용;백무열
    • 산업식품공학
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    • 제15권4호
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    • pp.382-387
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    • 2011
  • $POCl_{3}$ 농도(0.005%, 0.02%)를 달리한 가교화 쌀전분에 PO(2%, 6%, 12%)를 처리하여 가교화 후하이드록시프로필화(CLHP) 쌀전분을 제조하고, 변성된 CLHP 쌀전분의 용해도, 팽윤력, RVA, DSC 특성을 연구하였다. 팽윤력은 일반 쌀전분 보다 다소 낮은 온도에서 일찍 증가되기 시작하였으나 그 이후에 모두 낮은 수치를 보여 CLHP 쌀전분이 일반 쌀전분보다 완만한 상승을 나타내었고 용해도는 CLHP 쌀전분이 일반 쌀전분보다 전체적으로 낮은 결과를 나타내었다. RVA 분석결과 CLHP 쌀전분의 최고점도는 일반 쌀전분보다 낮아졌고 holding strength와 final viscosity는 높은 경향을 나타내었고, breakdown은 낮아지고 setback 은 높은 것으로 나타났다. DSC 분석 결과 CLHP 쌀전분의 $T_o$, $T_p$, $T_c$가 일반 쌀전분보다 낮게 나타났으며, ${\Delta}H$ 역시 작은 값을 보였으며 $Pol_{3}$ 함량에 따른 차이, 즉 가교화에 의한 차이는 크지 않았다. 따라서 가교화 후 하이드록시프로필화 한 쌀전분의 경우 RVA점도 특성은 가교화에 의한 영향이 크고 하이드록시프로필화에 따른 영향이 작다고 볼 수 있었으며, DSC열적특성은 가교화에 의한 영향으로 하이드록시프로필화가 원활하지 않았던 것으로 생각된다. 즉 인산기에 의해 강해진 전분 입자에 의해 하이드록시프로필기의 치환이 덜 일어난 것으로 판단된다.

기계화학적 극미세 가공기술을 이용한 PDMS 복제몰딩 공정용 서브마이크로 몰드 제작에 관한 연구 (A Study on the Fabrication of Sub-Micro Mold for PDMS Replica Molding Process by Using Hyperfine Mechanochemical Machining Technique)

  • 윤성원;강충길
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.351-354
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    • 2004
  • This work presents a simple and cost-effective approach for maskless fabrication of positive-tone silicon master for the replica molding of hyperfine elastomeric channel. Positive-tone silicon masters were fabricated by a maskless fabrication technique using the combination of nanoscratch by Nanoindenter ⓡ XP and XOH wet etching. Grooves were machined on a silicon surface coated with native oxide by ductile-regime nanoscratch, and they were etched in a 20 wt% KOH solution. After the KOH etching process, positive-tone structures resulted because of the etch-mask effect of the amorphous oxide layer generated by nanoscratch. The size and shape of the positive-tone structures were controlled by varying the etching time (5, 15, 18, 20, 25, 30 min) and the normal loads (1, 5 mN) during nanoscratch. Moreover, the effects of the Berkovich tip alignment (0, 45$^{\circ}$) on the deformation behavior and etching characteristic of silicon material were investigated.

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Antibodies against Nitric Oxide Damaged Poly L-Tyrosine and 3-Nitrotyrosine Levels in Systemic Lupus Erythematosus

  • Khan, Fozia;Ali, Rashid
    • BMB Reports
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    • 제39권2호
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    • pp.189-196
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    • 2006
  • Alterations in the amino acid structure or sequence can generate neo-epitopes from self-proteins causing autoaggressive immune attack. Reactive nitrogen species are an important factor that induces post-translational modification of proteins by cellular reduction and oxidation mechanism; cysteinyl-nitrosylation or tyrosine nitration leading to potentially pathogenic pathways. It was thought of interest to investigate the immunogenicity of nitrated poly L-tyrosine vis-$\`{a}$-vis its possible role in the induction of antibodies in systemic lupus erythematosus (SLE). Commercially available poly L-tyrosine was exposed to nitrating species and the damage was monitored by UV spectroscopy and alkaline gel electrophoresis. The results indicated the formation of 3-nitrotyrosine. Nitrated poly L-tyrosine induced higher titre antibodies as compared to the native form. Nitrated poly L-tyrosine was recognized by the autoantibodies present in the sera of patients suffering from SLE by enzyme immunoassays and band shift assay. The possible role of nitrated self-proteins has been discussed in the production of circulating anti-DNA antibodies in SLE.

대식세포(大食細胞) oxLDL 생성(生成)에 미치는 독활기생탕(獨活寄生湯)의 영향(影響) (Effects of Tokhwalkisaengtang on LDL Oxidation in Macrophage Cell)

  • 황귀서;송지연
    • 대한예방한의학회지
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    • 제4권2호
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    • pp.205-213
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    • 2000
  • The oxidative modification of low density lipoprotein(LDL) has been implicated in the development of atherosclerosis . Oxidized LDL(oxLDL) are found in macrophage foam cell , and it can induce an macrophage proliferation in atherosclerotic plaque. In this study, we investigated the hypothesis that Tokhwalkisaengtang(TK) may reduce atherosclerosis by lowering the oxidizability of LDL, To achieve this goal, we examined the effect of TK on LDL oxidation, nitric oxide production in murine macrophage cell line , and the effect of TK on cupuric sulfate-induced cytotoxicity. LDH release, and macrophage activity TK inhibited the generation of oxLDL from native LDL in macrophage cell culture, and decreased the release of LDH from cupric sulfate-stimulated macrophage. In other experiments, TK activated macrophase cell, and increased the survival rate, and enhanced nitric oxide production in macrophage.

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지단백산화(脂蛋白酸化)에 따른 대식세포(大食細胞) 활성(活性)에 미치는 삼기음(三氣飮)의 영향(影響) (Effects of Samkieum on LDL Oxidation in Macrophage Cell)

  • 이희조;황귀서;김경준
    • 한방안이비인후피부과학회지
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    • 제19권2호
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    • pp.108-117
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    • 2006
  • The oxidative notification of low density lipoprotein(LDL) has been implicated in the development of atherosclerosis. Oxidized LDL are found in macrophage foam cell, and it can induce an macrophage proliferation in atherosclerotic plaque. In this study, we investigated the hypothesis that Samkieum may reduce atherosclerosis by lowering the oxidiazability of LDL, To achieve this goal, we examined the effect of Samkieum on LDL oxidation nitric oxide production in mouse macrophage cell line, RAW264.7, and the effect of Samkieum on cupuric sulfate-induced cytotoxicity, LDH release, and macrophage activity. Samkieum inhibited the generation 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, Samkieum activated RAW264.7 cell, and prolonged the survival time, and increased nitric oxide production in Raw 264.7 cells.

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PAE법에 의한 GaAs/Ge/Si 이종접합 성장과 그 특성 (GaAs/Ge/Si Heteroepitaxy by PAE and Its Characteristics)

  • 김성수;박상준;이성필;이덕중;최시영
    • 전자공학회논문지A
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    • 제28A권5호
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    • pp.380-386
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    • 1991
  • Hydrogen plasma-assisted epitaxial(PAE) growth of GaAs/Si and GaAs/Ge/Si with Ge buffer layer has been investigated. By means of photoluminescence, Nomarski microscopu, and $\alpha$-step, it could be known that GaAs on Si with Ge buffer layer has better crystalline quality than GaAs on Si without Ge buffer layer. The stoichiometry of GaAs layer on Si was confirmed by the depth profile of Auger electron spectroscope (AES). Also the native oxide(SiO$_2$) layer on Si substrate was plama-etched and the removal of the oxide layer was confirmed by AES. Photoluminescence peak wavelength of GaAs/Ge/Si with Ge buffer of 1\ulcorner thickness and GaAs growth rate of 160$\AA$/min was 8700$\AA$and FWHM was 12$\AA$.

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가미소요산(加味逍遙散)이 지단백산화(脂蛋白酸化)에 따른 RAW 264.7 활성(活性)에 미치는 영향(影響) (Effects of Gamisoyosan(GS) on LDL Oxidation in RAW 264.7 Cell.)

  • 황귀서
    • 대한예방한의학회지
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    • 제5권1호
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    • pp.134-143
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    • 2001
  • The oxidative modification of low density lipoprotein(LDL) has been implicated in the development of atherosclerosis. Oxidized LDL are found in macrophage foam cell, and it can induce an macrophage proliferation in atherosclerotic plaque. In this study, we investigated the hypothesis that gamisoyosan(GS) may reduce atherosclerosis by lowering the oxidiazability of LDL, To achive this goal, we examined the effect of GS on LDL oxidation, nitric oxide production in mouse macrophage cell line, RAW264.7, and the effect of GS on cupuric sulfate-induced cytotoxicity, LDH release, and macrophage activity. GS inhibited the generation 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, GS activated RAW264.7 cell, and prolonged the survival time, and increased nitric oxide production in Raw 264.7 cells.

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NH$_3$-pplasma Treatment of GaAs Surface at High Tempperature in RF pparallel pplate pplasma Reactor

  • ppark, Kyoung-Wan;Lee, Seong-Jae-;Kim, Gyungock-;Lee, El-Hang-
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 1993년도 제4회 학술발표회 논문개요집
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    • pp.29-31
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    • 1993
  • NH3-pplasma treatment has been used for ppassivation of native-oxide-contaminated GaAs surface. Ex-situ band-gapp pphotoluminescence(ppL) measurement shows enhanced intensity for the treated surfaces. Auger electron sppectroscoppy(AES) shows that the treated surface contains nitrogen atoms but no arsenic atoms, which leads us to sppeculate that the graded GaN thin layer was formed on the surface. Based on these results, new metal-insulator-GaAs structure is ppropposed.

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Improvement in Electrical Stability of poly-Si TFT Employing Vertical a-Si Offsets

  • Park, J.W.;Park, K.C.;Han, M.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.67-68
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    • 2000
  • Polycrystalline silicon (poly-Si) thin film transistors (TFT's) employing vertical amorphous silicon (a-Si) offsets have been fabricated without additional photolithography processes. The a-Si offset has been formed utilizing the poly-Si grain growth blocking effect by thin native oxide film during the excimer laser recrystallization of a-Si. The ON current degradation of the new device after 4 hour's electrical stress was reduced by 5 times compared with conventional poly-Si TFT's.

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