• 대한한방내과학회지
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• 제31권1호
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• pp.153-165
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• 2010

Objectives : The aims of this study were to investigate the cytoprotective, antioxidative and inflammation genes inhibitory effects of Patriniae Radix on the mouse LLC-$PK_1$ cells (renal epithelial cells). Methods : The cytoprotective effect of Patriniae Radix was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The antioxidative effect was measured in terms of generation amount of superoxide anion radical (${\cdot}{O_2}^-$) by 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), nitric oxide (NO) by 4,5-diaminofluorescein (DAF-2), peroxynitrite ($ONOO^-$) by dihyldrorhodamine 123 (DHR 123) and prostaglandin $E_2$ ($PGE_2$) by $PGE_2$ immunoassay on $H_2O_2$-treated LLC-$PK_1$ cells. For measuring of inflammation genes inhibitory effects, western blot was performed to detect IKK-$\alpha$, phospho-$I{\kappa}B-\alpha$, NF-${\kappa}B$ (p50, p65), COX-2, iNOS, IL-$1{\beta}$ and VCAM-1 protein level in cytosol fractions from LLC-$PK_1$ cells. Results : Patriniae Radix extract reduced the $H_2O_2$-induced cell death and inhibited the amount of $H_2O_2$-induced ${\cdot}{O_2}^-$, NO, $ONOO^-$, $PGE_2$ generation dose-dependently on the mouse LLC-$PK_1$ cells in vitro. Also Patriniae Radix extract inhibited the expression of IKK-$\alpha$, phospho-$I{\kappa}B-\alpha$, COX-2, iNOS, IL-$1\beta$ and VCAM-1 genes dose-dependently by means of decreasing activation of NF-${\kappa}B$. Conclusions : According to above results, it was identified that Patriniae Radix had the cytoprotective, antioxidative and inflammation genes inhibitory effects. So it was suggested that Patriniae Radix would be effective to the treatment for the inflammatory process and inflammation-related diseases.

• 치위생과학회지
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• 제19권3호
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• pp.198-204
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• 2019

Background: Oxidative stress is a known to be associated with in the pathogenesis of many inflammatory diseases, including periodontitis. Ursolic acid is a pentacyclic triterpenoid with has antimicrobial, antioxidative, and anticancer properties. However, the role of ursolic acid in the regulating of osteogenesis remains undetermined. This study was aimed to elucidate the crucial osteogenic effects of ursolic acid and its ability to inhibit oxidative stress by targeting the immediate early response 3 (IER3)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Methods: Cell proliferation was determined using water-soluble tetrazolium salt assay, cell differentiation was evaluated by alkaline phosphatase (ALP) activity, and formation of calcium nodules was detected using alizarin red S stain. Generation of reactive oxygen species (ROS) was determined using by DCFH-DA fluorescence dye in hydrogen peroxide ($H_2O_2$)-treated MG-63 cells. Expression levels of IER3, Nrf2, and heme oxygenase-1 (HO-1) were analyzed using western blot analysis. Results: Our results showed that ursolic acid up-regulated the proliferation of osteoblasts without any cytotoxic effects, and promoted ALP activity and mineralization. $H_2O_2$-induced ROS generation was found to be significantly inhibited on treatment with ursolic acid. Furthermore, in $H_2O_2$-treated cells, the expression of the early response genes: IER3, Nrf2, and Nrf2-related phase II enzyme (HO-1) was enhanced in the presence of ursolic acid. Conclusion: The key findings of the present study elucidate the protective effects of ursolic acid against oxidative stress conditions in osteoblasts via the IER3/Nrf2 pathway. Thus, ursolic acid may be developed as a preventative and therapeutic agent for mineral homeostasis and inflammatory diseases caused due to oxidative injury.

• 한국작물학회지
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• 제20권
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• pp.107-114
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• 1975

유채성분육종을 효율적으로 수행하기 위한 수단으로써 세대단축기수를 개발코자 전 I, II 보를 통하여 Green Plant Vernalization과 고온처리에서 채종후 46~49일째 개화하는데까지 가능하였으나 개화수분후 등숙기간의 발아능력은 2개월이상의 숙도와 일정기간을 경과치 않고는 발아력을 갖추지 않는다는 것도 인정되었다. 여기서는 등숙기간의 발아능력을 촉진코자 시험을 실시하였든바 기결과를 요약하면 다음과 같다. 1. 유채의 발아촉진제 Hydroperoxide($H_2O$$_2$)를 사용하여도 개화후 40일 이전에는 발아치 않으며 40일이후에도 50%이하의 발아력을 가질뿐이며(생체종자)종자를 Heating했을 때만이 55일에서 90% 이상이 발아능력을 가지고 있을 뿐이다. 2. 개화후 Ethrel처리시기는 개화후 15일에 Ethrel 처리후의 유효발아율에 도달하는 것은 10~15일째였었다. 3. Ethrel농도로는 일정한 경향은 없으나 개화후 15일 Ethrel 2,000ppm처리한 다음 처리후 10일째 (총등숙소요일수 25일)에 76% 발아되였으며 Ethrel 500ppm처리한 것은 처리후 15일째 (총등숙소요일수 30일)에 96% 발아능력을 가지고 있어서 가장 효과적이였다. 4. 유채에서 Ethrel과 Hydroperoxide처리로 개화후 25~30일에 76~96%의 발아율로 무려 1개월이상 등숙기간을 단축할수 있었든 것은 각 약제의 상가적인 효과라기보다 두 약제의 상승효과로 인정된다. 5. 유채세대단축은 1세대에 66일~71일을 소요하며 년간 4세대 내지 5세대를 단축할 수 있을 것으로 인정되었다.

• 분석과학
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• 제12권6호
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• pp.484-489
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• 1999

화산암중의 미량의 Se을 정량하기 위하여 수소화물발생법에 의한 원자 흡수 분광광도법을 이용하여 Se을 정량하였다. 암석시료를 가압형 시료분해 용기에서 $HNO_3$, $HClO_4$, HF로 분해한 후 테프론 증발접시에 옮겨 가열 농축하였다. 그 후에 KBr과 HCl용액을 가하여 가열해서 시료중의 미량 Se을 4가로 환원시킨후 강환원제인 3% $NaBH_4$용액을 첨가하여 생성된 $H_2Se$를 일정류량의 질소로 gas 추출하여 $KMnO_4$용액중에 2회 반복 흡수시키고 이것을 환원기와 원자 흡수 분광광도법에 의하여 정량하였다. 그 결과 2회 gas 추출함으로써 종래에 측정이 곤란하였던 암석중의 극미량의 Se을 정확하게 정량분석할 수 있었다. 예로 화산암중 류문암석을 선택하여 Se을 6회 정량한 결과 확률수준 95%에 있어서 $19.5{\pm}1.3ng/g$의 정도로 정량되었다.

• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.996-1000
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• 2005

Experimental results are presented for the degradation of 3 nm-thick gate oxide $(SiO_2)$ under both Negative-bias Temperature Instability (NBTI) and Hot-carrier-induced (HCI) stresses using P and NMOSFETS, The devices are annealed with hydrogen or deuterium gas at high-pressure $(1\~5\;atm.)$ to introduce higher concentration in the gate oxide. Both interface trap and oxide bulk trap are found to dominate the reliability of gate oxide during electrical stress. The degradation mechanism depends on the condition of electrical stress that could change the location of damage area in the gate oxide. It was found the trap generation in the gate oxide film is mainly related to the breakage of Si-H bonds in the interface or the bulk area. We suggest that deuterium bonds in $SiO_2$ film are effective in suppressing the generation of traps related to the energetic hot carriers.

• 한국세라믹학회지
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• 제45권9호
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• pp.524-530
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• 2008

Anti-Reflective (AR) thin film coatings of $SiO_2$ (n= 1.48) and $TiO_2$ (n=2.17) were deposited by ion-beam assisted deposition (IBAD) with End-Hall ion source and conventional electron beam (e-beam) evaporation to investigate the effect of deposition method on the refractive indicies (n) of the fIlms. Green-light generation using a GaAs laser diode was achieved via excitation of the second harmonic. The latter resulted from the transmission of the fundamental guided-mode wave of 1064 nm through periodically poled $LiNbO_3$. Large differences in the refractive indicies of each of the layers in the multilayer coating may improve AR performance. IBAD of $SiO_2$ reduced its refractive index from 1.45 to 1.34 at 1064 nm. Conversely, e-beam evaporation of $TiO_2$ increased its refractive index from 1.80 to 2.11. In addition, no fluctuations in absorption at the wavelength of 1064 nm were found. The results suggest that films prepared by different deposition methods can increase the effectiveness of multilayer AR coatings.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권2호
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• pp.76-82
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• 2003

The robust stack storage node and sufficient cell capacitance for high performance is indispensable for 90 nm DRAM capacitor. For the first time, we successfully demonstrated MIS capacitor process integration for 90 nm DRAM technology. Novel cell layout and integration technology of 90 nm DRAM capacitor is proposed and developed, and it can be extended to the next generation DRAM. Diamond-shaped OCS with 1.8 um stack height is newly developed for large capacitor area with better stability. Furthermore, the novel $Al_2O_3/HfO_2$ dielectric material with equivalent oxide thickness (EOT) of 25 ${\AA}$ is adopted for obtaining sufficient cell capacitance. The reliable cell capacitance and leakage current of MIS capacitor is obtained with ~26 fF/cell and < 1 fA/ceil by $Al_2O_3/HfO_2$ dielectric material, respectively.

• 한국결정성장학회지
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• 제20권6호
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• pp.278-282
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• 2010

Tm 도핑에 따른 $BaTiO_3$ ceramics의 전기적 특성과 열화 거동에 미치는 영향에 대하여 core-shell 형성과 가속열화시험에 의한 미세화학변화의 관점에서 연구하였다. $Tm_2O_3$를 첨가하지 않은 $BaTiO_3$와 1 mol%를 첨가한 $BaTiO_3$를 펠렛과 적층 형태의 시편으로 각각 제조하였다. 1 mol% $Tm_2O_3$가 첨가된 유전체 시편의 유전상수는 $Tm_2O_3$를 첨가하지 않은 시편에 비해 약 40% 높게 나타났고 X7R 조건을 만족하였다. 절연저항 또한 1 mol% $Tm_2O_3$가 첨가된 시편은 $5.43{\times}10^{10}{\Omega}$으로 $Tm_2O_3$를 첨가하지 않은 시편의 $1.11{\times}10^{10}{\Omega}$보다 높게 나타났다. 이는 $Tm^{3+}$ 이온이 Ba site와 Ti site에 선택적으로 치환되고 유전체 미세조직 내에 core-shell 구조를 형성하여 전기적 특성을 향상시킨 것으로 설명된다. 각각의 조성에 따라 제조된 적층 시편의 $150^{\circ}C$, 70 V, 24시간 가속열화시험결과에 따르면, 1 mol% $Tm_2O_3$가 첨가된 $BaTiO_3$는 첨가되지 않은 시편에 비해 전극 층으로의 산소확산이 감소됨을 확인하였고, 이는 $Tm^{3+}$ 이온의 Ti site 치환에 의해 발생한 산소공공이 Ni 전극과 반응할 수 있는 과잉 산소를 줄여주기 때문으로 판단된다.

• 전자공학회논문지
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• 제54권1호
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• pp.21-25
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• 2017

본 연구에서는 최근 차세대 전력 반도체로 관심을 받고 있는 단결정 ${\beta}-Ga_2O_3$를 이용한 쇼트키 배리어 다이오드 제작 및 특성 분석을 수행하였다. 쇼트키 배리어 다이오드는 Sn으로 도핑된 $2{\mu}m$ 두께의 저농도 N 타입 에피층 상에 Pt/Ti/Au 쇼트키 접합으로 제작되었으며 측정된 특성은 > 180 V의 항복전압, $1.26m{\Omega}{\cdot}cm^2$의 온 저항, 그리고 1 V의 순 방향 전압에서 $77A/cm^2$, 1.5 V에서 $473A/cm^2$의 순방향 전류 특성을 나타내었다. 본 연구를 통하여 단결정 ${\beta}-Ga_2O_3$의 전력반도체 활용 가능성을 확인 할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2241-2247
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• 2007

A new series of chiral bent-shaped liquid crystals with an asymmetric central core based on 1,6- dihydroxynaphthalene and chiral terminal chain prepared from (S)-(?)-2-methyl-1-butanol, 1,6-naphthalene bis[4-(4-alkoxyphenyliminomethyl)]benzoates [N(1,6)-n-O-PIMB(n-2)*-(n-4)O (n = 8-11)] were synthesized. Their mesomorphic properties and phase structures were investigated by means of electro-optical, polarization reversal current, and second harmonic generation measurements in order to confirm the relationship between the molecular structure and phase structure. All odd n (n = 9 and 11) compounds, N(1,6)-9-O-PIMB7*-5O and N(1,6)-11-O-PIMB9*-7O exhibit antiferroelectric phase, whereas even n (n = 8 and 10) compounds was flexible, N(1,6)-10-O-PIMB8*-6O exhibits the ferroelectric phase but N(1,6)-8-O-PIMB6*-4O exhibits the antiferroelectric phase. These results come from the decrease of the closed packing efficiency within a layer and the lack of uniform interlayer interaction between adjacent layers, which were caused by the asymmetrical naphthalene central core. Thus, we concluded that the structure of central core as well as the terminal chain plays an important role for the emergence of particular polar ordering in phase structures.