• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.144-144
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• 2002

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.232-233
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• 2008

The 4H-SiC schottky diodes treated by the various dry etch methods were fabricated and electrically characterized. The post etch process including an Inductively Coupled Plasma(ICP) etch and a Neutron Beam Etch(NBE) was performed after a high-temperature activation annealing without graphite cap in order to eliminate the damaged surface generated during the activation annealing. The reverse leakage current of diode treated by ICP was 1/35 times lower than that of the diode without any post etch at the anode bias of -100V, while the reverse leakage current of diode treated by NBE was 1/44 times lower at the same bias.

• 대한한의학회지
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• 제22권4호
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• pp.45-57
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• 2001

Objectives : The water extract of Gwibitang (GBT) has been traditionally used for treatment of psychologic disease and brain damage in Oriental Medicine, This study was designed to investigate the effect of GBT on the glutamate-induced toxicity of rat C6 glial cells. Methods : The cultured cells were pretreated with GBT and exposed to glutamate, The cell damage was assessed by using MTT assay and Hoechst, IC-l staining, Results : GBT had protective effects in glutamate-induced cytotoxicity, which was revealed as apoptosis characterized by chromatic condensation and the loss of mitochondrial membrane potential in C6 glial cells. However, GBT and glutamate had no effect in the activation of caspase family cysteine proteases including caspase-3, -8 and -9 proteasesin C6 glial ce]]s, GBT significantly recovered the depletion of GSH and inhibited the generation of $H_2O_2$ by glutamate in C6 glial cells. In addition, both GBT and antioxidants such as GSH and NAC protected the glutamate-induced cytotoxicity in C6 glial cells, indicating that GBT possibly has antioxidative effect. Moreover, GBT also inhibited the glutamate-induced degradation of $IkB{\alpha}$ in C6 glial cells, This result suggest that GBT has some inhibitory effects on the transcriptional activation of $NF-_{k}B$. Conclusions : GBT has protective effects in glutamate-induced cytotoxicity via an antioxidative mechanism.

• 한국재료학회지
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• 제22권7호
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• pp.346-351
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• 2012

$Li_{1+x}Al_xTi_{2-x}(PO_4)_3$(LATP) is a promising solid electrolyte for all-solid-state Li ion batteries. In this study, LATP is prepared through a sol-gel method using relatively the inexpensive reagents $TiCl_4$. The thermal behavior, structural characteristics, fractured surface morphology, ion conductivity, and activation energy of the LATP sintered bodies are investigated by TG-DTA, X-ray diffraction, FE-SEM, and by an impedance method. A gelation powder was calcined at $500^{\circ}C$. A single crystalline phase of the $LiTi_2(PO_4)_3$(LTP) system was obtained at a calcination temperature above $650^{\circ}C$. The obtained powder was pelletized and sintered at $900^{\circ}C$ and $1000^{\circ}C$. The LTP sintered at $900{\sim}1000^{\circ}C$ for 6 h had a relatively low apparent density of 75~80%. The LATP(x = 0.3) pellet sintered at $900^{\circ}C$ for 6 h was denser than those sintered under other conditions and showed the highest ion conductivity of $4.50{\times}10^{-5}$ S/cm at room temperature. However, the ion conductivity of LATP (x = 0.3) sintered at $1000^{\circ}C$ decreased to $1.81{\times}10^{-5}$ S/cm, leading to Li volatilization and abnormal grain growth. For LATP sintered at $900^{\circ}C$ for 6 h, x = 0.3 shows the lowest activation energy of 0.42 eV in the temperature range of room temperature to $300^{\circ}C$.

• 한국수소및신에너지학회논문집
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• 제25권4호
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• pp.337-343
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• 2014

This study was conducted to evaluate the characteristics of dark fermentative $H_2$ production from microalgae (Chlorella vulgaris) using batch reactors under mesophilic (25, $35^{\circ}C$) and thermophilic (45, $55^{\circ}C$) conditions. The $H_2$ yield and $H_2$ production rate increased with increasing temperature. The maximum $H_2$ yield and $H_2$ production rate were 56.77 mL $H_2/g$ dcw, 3.33 mL $H_2/g\;dcw{\cdot}h$ at $55^{\circ}C$, respectively. The activation energy calculated using Arrhenius equation was 36.24 kcal/mol, which was higher than that of dark $H_2$ fermentation of glucose by anaerobic mixed culture. Although the concentration of butyrate was maintained, the concentrations of lactate and acetate increased with increasing temperature. The $H_2$ yield was linearly proportional to acetate/ butyrate ratio.

• 마이크로전자및패키징학회지
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• 제8권2호
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• pp.1-7
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• 2001

저열팽창성 금속인 Kovar표면을 유리와 접합하기에 적합한 spinel을 주상으로 하는 균일한 산화막을 형성할 수 있도록 $N_2/H_2$에 $H_2O$가 첨가된 분위기에서의 산화 거동에 대하여 조사하였다. Kovar 산화는 확산에 의해 지배되는 공정이며, 이때 산화 활성화 에너지는 31.61 kacl/mol 이었다. $600^{\circ}C$에서 열처리한 결과 spinel을 주상으로 하는 0.5 $mu extrm{m}$ 이하의 연속적이고 균일한 외부 산화막을 얻을 수 있었다. TEM 분석 결과 격자 상수가 7.9 $\AA$인 spinel 임을 확인할 수 있었다. 그러므로, 가습된 $N_2/H_2$분위기에서 산화한 Kovar는 유리와 접합에 적용 가능할 것으로 판단된다.

• BMB Reports
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• 제50권10호
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• pp.522-527
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• 2017

A large number of transcriptional activation domains (TADs) are intrinsically unstructured, meaning they are devoid of a three-dimensional structure. The fact that these TADs are transcriptionally active without forming a 3-D structure raises the question of what features in these domains enable them to function. One of two TADs in human glucocorticoid receptor (hGR) is located at its N-terminus and is responsible for ~70% of the transcriptional activity of hGR. This 58-residue intrinsically-disordered TAD, named tau1c in an earlier study, was shown to form three helices under trifluoroethanol, which might be important for its activity. We carried out heteronuclear multi-dimensional NMR experiments on hGR tau1c in a more physiological aqueous buffer solution and found that it forms three helices that are ~30% pre-populated. Since pre-populated helices in several TADs were shown to be key elements for transcriptional activity, the three pre-formed helices in hGR tau1c delineated in this study should be critical determinants of the transcriptional activity of hGR. The presence of pre-structured helices in hGR tau1c strongly suggests that the existence of pre-structured motifs in target-unbound TADs is a very broad phenomenon.

• Applied Biological Chemistry
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• 제39권3호
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• pp.245-248
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• 1996

식품첨가물로서의 활용가능성을 검색하기위해, 한국산 유색미(Oryza sutiva var. Suwon 415)의 주요색소인 cyanidin 3-히ucoside의 열안정성과 pH 변화에 따른 UV/Vis 스펙트럼의 변화에 대해 연구하였다. 유색미의 안토시아닌 색소는 산성(pH 2.0)과 염기성(pH 9.0) 완충용액에서 각각 강한 적색과 청색을 나타내었고 열에 의한 색소의 분해반응은 20mM phosphate (PH 2.0)와 20mM CHES (pH 9.0) 완충용액에서 $50{\sim}95^{\circ}C$의 온도범위에서 수행되었다. 색소의 분해정도는 UV/Vis 스펙트럼의 변화를 측정하여 결정하였으며, 350nm (pH 2.0)와, 275, 310, 및 405nm (pH9.0)에서 isosbestic를 나타내었다. 이 결과는 색소분해반응이 1차 반응임을 의미한다. 유색미 안토시아닌은 산성조건에서 매우 안정하였고 염기성조건에서도 비교적 안정하였으며, 반감기는 $70^{\circ}C$에서 각각 50.3h과 0.6h이었다. 색소분해반응의 활성화에너지$(E_a)$와 Arrhenius frequence facto(A)는 pH 2.0에서는 26.9kcal $mol^{-1}$과 $6.0{\times}10^{11}\;s^{-1}$이었고, pH 9.0에서는 152Kcal $mol^{-1}$과 $1.4{\times}10^{6}\;s^{-1}$이었다.

• Molecules and Cells
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• 제27권1호
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• pp.113-118
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• 2009

In this study, we have shown the transcriptional regulation of the human GD3 synthase (hST8Sia I) induced by valproic acid (VPA) in human neuroblastoma SK-N-BE(2)-C cells. To elucidate the mechanism underlying the regulation of hST8Sia I gene expression in VPA-stimulated SK-N-BE(2)-C cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5'-flanking region of the hST8Sia I gene by the transient expression method showed that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-${\kappa}B$, functions as the VPA-inducible promoter of hST8Sia I in SK-N-BE(2)-C cells. Site-directed mutagenesis and electrophoretic mobility shift assay indicated that the NF-${\kappa}B$ binding site at -731 to -722 was crucial for the VPA-induced expression of hST8Sia I in SK-N-BE(2)-C cells. In addition, the transcriptional activity of hST8Sia I induced by VPA in SK-N-BE(2)-C cells was strongly inhibited by SP600125, which is a c-Jun N-terminal kinase (JNK) inhibitor, and $G{\ddot{O}}6976$, which is a protein kinase C (PKC) inhibitor, as determined by RT-PCR (reverse transcription-polymerase chain reaction) and luciferase assays. These results suggest that VPA markedly modulated transcriptional regulation of hST8Sia I gene expression through PKC/JNK signal pathways in SK-N-BE(2)-C cells.

• 대한화학회지
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• 제41권12호
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• pp.645-652
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• 1997

클로로착물 Cp*Ru(CO)(PR3)H (Cp*=η5-C5Me5, PR3=PMe3, PEt3, PMePh2, PPh3, PCy3)을 출발물질로 사용하여 다양한 히드리드화시약(NaBH4, LiAlH4, LiBEt3H)이나 NaOMe를 반응시켜서 대응하는 히드리드착물 Cp*Ru(CO)(PCy3)H(5)를 합성하였다. Cp*Ru(CO)(PCy3)H(5)착물의 C6D6ㅇ용액에 UV를 조사하면 분자간 및 분자내 C-H결합 활성화반응을 통하여 용매의 중수소와 착물의 배위 리간드인 Cp*, PCy3, Ru-H의 수소 사이에 H/D 교환반응이 진행되었으며 그 반응기구를 설명하였다.