• 한국표면공학회지
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• 제41권4호
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• pp.169-173
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• 2008

The objective of this study is to coat the $SiO_2$ layer uniformly on the ZnS:Cu phosphors by using Sol-Gel method. From results of SEM micrographs observation, XRD and XPS analysis, it could be confirmed that $SiO_2$ layer was relatively well coated on ZnS:Cu particles. $Ag_2S$ was used as a decoding chemical to analyze the dense and uniform coating performance of $SiO_2$ layer on phosphor particles. It could be concluded that phosphors synthesized from our two step replacement method showed strong blue peak comparing to other method and rather weak green peak also. Obtained particle size of phosphors were about 20m diameter. Luminescence properties of the phosphors were examined by photoluminescence spectra at the excitation wavelength of 270 nm.

• 대한전자공학회논문지
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• 제22권3호
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• pp.1-5
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• 1985

Bridgnan방법으로 성장시킨 CuInse2단결정을 Se분위기 속에서 열처리하여 carrier농도가 2.6×1016/㎤인 n·Culnse2단결정을 얻었다. 이 단결정을 photoanode로 하고 polysulfide용액으로 3M KOH+3M Na2S+4M S를 사용하여 n·Culnsel-3M KOH+3M Na2S+4M S접합의 태양전지를 만들었다. 이 태양전지는 태양에너지 100mW/㎤의 조건하에서 FF=0.44이며, 태양에너지 변환효율은 5.67% 이었다.

• 한국토양비료학회지
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• 제28권4호
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• pp.306-311
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• 1995

다양필수원소(多量必須元素)중의 하나인 유황(硫黃)이 옥수수의 초기생육에 미치는 영향을 구명하기 위하여 1995년(年) 5월(月) 22일(日) 부터 1995년(年) 7월(月) 10일(日)까지 경희대학교(慶熙大學校) 수원(水原)캠퍼스 온실(溫室)에서 옥수수 광안옥 품종(品種)과 횡성옥 품종(品種)을 공시재료(供試材料)로 하여 7주간 양액재배로 실시하였다. 유황 시비처리는 양액에 $MgSO_4{\cdot}7H_2O$를 첨가하여 조절하되 양액중 유황농도는 무류황구(無硫黃區)(-S)가 0ppm, 대조구(對照區)(C)가 68ppm, 2배시용구(倍施用區)(2S)가 136ppm, 3배시용구(倍施用區)(3S)가 204ppm이 되도록 하였다. 파종후(播種後) 매주(每週)마다 옥수수의 초장(草長), 엽면적(葉面積), 건물중(乾物重)을 조사(調査)한 결과(結果)를 보면 7주간(週間)의 생육(生育)에 있어서 광안옥 품종(品種)의 초장(草長)은 C>2S>3S>-S구(區), 엽면적(葉面積)은 2S구(區)>C구(區)>3S구(區)>-S구(區), 그리고 건물중(乾物重)은 2S구(區)>3S구(區)>C구(區)>-S구(區) 순(順)으로 신장하였고 횡성옥 품종(品種)에 있어서 초장(草長)은 C구(區)>-S구(區)>3S구(區)>2S구(區), 엽면적(葉面積)은 C구(區)>3S구(區)>2S구(區)>-S구(區), 건물중(乾物重)은 C구(區)>3S구(區)>-S구(區)>2S구(區) 순(順)으로 증가(增加)하였다. 전실험기간(全實驗期間)동안 초장(草長), 엽면적(葉面積), 건물중(乾物重)을 통합한 결과(結果)는 두 품종(品種) 공히 무류황시용구(無硫黃試用區)(-S)에서 가장 저조(低調) 하였고 횡성옥 품종(品種)에서는 C구(區)가 가장 증가(增加)하였다. 작물생장율(作物生長率)(CGR)은 두 품종(品種) 모두 파종후(播種後)부터 3주(週)까지는 완만(緩慢)한 증가(增加)를 보이다가 파종후(播種後) 4주(週)째부터는 증감(增減)이 크게 교차(交叉) 현상을 보였지만 횡성옥 품종(品種)의 C구(區)는 계속 증가(增加)하였다.

• International Journal of Oral Biology
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• 제31권4호
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• pp.127-133
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• 2006

[ $H_2O_2$ ], a member of reactive oxygen species (ROS), is known to be involved in the mediation of physiological functions in a variety of cell types. However, little has been known about the physiological role of $H_2O_2$ in exocrine cells. Therefore, in the present study, the effect of $H_2O_2$ on cholecystokinin (CCK)-evoked $Ca^{2+}$ mobilization and amylase release was investigated in rat pancreatic acinar cells. Stimulation of the acinar cells with sulfated octapeptide form of CCK (CCK-8S) induced biphasic increase in amylase release. Addition of $30\;{\mu}M\;H_2O_2$ enhanced amylase release caused by 10 pM CCK-8S, but inhibited the amylase release induced by CCK-8S at concentrations higher than 100 pM. An ROS scavenger, $10\;{\mu}M$ Mn(III)tetrakis(4-benzoic acid)porphyrin chloride, increased amylase release caused by CCK-8S at concentrations higher than 100 pM, although lower concentrations of CCK-8S-induced amylase release was not affected. To examine whether the effect of $H_2O_2$ on CCK-8S-induced amylase release was exerted via modulation of intracellular $Ca^{2+}$ signaling, we measured the changes in intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in fura-2 loaded acinar cells. Although $30\;{\mu}M\;H_2O_2$ did not induce any increase in $[Ca^{2+}]_i$ by itself, it increased the frequency and amplitude of $[Ca^{2+}]_i$ oscillations caused by 10 pM CCK-8S. However, $30\;{\mu}M\;H_2O_2$ had little effect on 1 nM CCK-8S-induced increase in $[Ca^{2+}]_i$. ROS scavenger, 1 mM N-acetylcysteine, did not affect $[Ca^{2+}]_i$ changes induced by 10 pM or 1 nM CCK-8S. Therefore, it was concluded that $30\;{\mu}M\;H_2O_2$ enhanced low concentration of CCK-8S-induced amylase release probably by increasing $[Ca^{2+}]_i$ oscillations while it inhibited high concentration of CCK-8S-induced amylase release.

• Bulletin of the Korean Chemical Society
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• 제23권1호
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• pp.123-131
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• 2002

Solvolyses rate constant of 1- and 2- naphthoyl chlorides (1 and 2) are reported for aqueous binary mixtures with methanol, ethanol, fluorinated alcohol, acetonitrile and dioxane. Kinetic solvent isotope effects (KISE) in methanol and product selectivities (S) of 2-naphthoyl chloride (2) in alcohol-water are also reported. Dispersions in Grunwald-Winstein correlations $(r{\leq}0.901)$ are discussed by multiple regression analysis incorporating ionizing power $(Y_{Cl})$ scale and rate-rate profiles. Major causes for these phenomena are investigated as an aromatic ring solvation effects, in conjunction with weakly nucleophilic solvation effects ($S_N2$ character), for solvolyses of 1 and for solvolyses of 2, as dual reaction channels, described as $S_N1$-$S_N2$ and $S_AN$-$S_N2$ processes. Distinct border lines between the two pathways are derived from solvolyses rates of 2 in 18 solvent using the results of $log(k/k_o)=mY_{Cl}+lN_T+hI$ plot with values of 1.13 for m, 0.37 for l and 0.15 for h value in 5 aqueous fluorinated alcohol mixtures. Using rate-product correlation, the validity of a third order model based on a general base catalyzed by solvent and contribution from these rate constants, $k_{aa},\;k_{aw}$ and $k_{aw}$, are investigated for $S_AN$-$S_N2$ solvolyses of 2 favored in more rich alcohol media and gradual addition of water to alcohol solvent shows a great shift away from stoichiometric solvation to predominantly medium effects. Rate-rate correlation between solvolyses of 2 and trimethyl acetylchloride (5) with alkyl group in the 29 aqueous solvent mixtures shows appreciable linearity (slope = 0.84, r = 0.987), caused by the same pathway ($S_N1$-$S_N2$ process), even if this correlation coincides with appreciable dispersion (different solvation effect).

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.591-602
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• 2019

Human breast cancer cell line, MDA-MB-231, is highly invasive and aggressive, compared to less invasive cell line, MCF-7. To explore the genes that might influence the malignancy of MDA-MB-231, DNA microarray analysis was performed. The results showed that G0/G1 switch 2 (G0S2) was one of the most highly expressed genes among the genes upregulated in MDA-MB-231. Although G0S2 acts as a direct inhibitor of adipose triglyceride lipase, action of G0S2 in cancer progression is not yet understood. To investigate whether G0S2 affects invasiveness of MDA-MB-231 cells, G0S2 expression was inhibited using siRNA, which led to decreased cell proliferation, migration, and invasion of MDA-MB-231 cells. Consequently, G0S2 inhibition inactivated integrin-regulated FAK-Src signaling, which promoted Hippo signaling and inactivated ERK1/2 signaling. In addition, G0S2 downregulation decreased ${\beta}$-catenin expression, while E-cadherin expression was increased. It was demonstrated for the first time that G0S2 mediates the Hippo pathway and induces epithelial to mesenchymal transition (EMT). Taken together, our results suggest that G0S2 is a major factor contributing to cell survival and metastasis of MDA-MB-231 cells.

• 한국약용작물학회지
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• 제14권4호
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• pp.250-254
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• 2006

황기속 식물 3종 (황기, 제주황기, A. mongholicus)을 대상으로 핵형 분석과 45S와 5S rDNA를 이용한 bicolor-FISH를 수행하였다. 체세포 염색체 수는 모두 2n=2x=16으로 관찰되었고, 염색체의 평균 길이는 $2.19{\sim}5.73\;{\mu}m$이였다. 황기의 염색체는 4쌍의 중부염색체 (염색체 3, 5, 6, 7)와, 차중부 염색체 (염색체 1, 2, 4, 8)로 구분되었다. 제주황기는 2쌍의 중부 염색체 (염색체 4, 8)와 6쌍의 차중부 염색체 (염색체 1, 2, 3, 5, 6, 7)로 A. mongholicus는 2쌍의 중부 염색체 (염색체 7, 8)와 6쌍의 차중부 염색체 (염색체 1, 2, 3, 4, 5, 6)로 각각 구분되었다. bicolor-FISH 기법을 이용하여 45S와 5S rDNA의 염색체상의 위치를 확인한 결과, 황기와 A. mongholicus에서는 1쌍의 45S와 5S rDNA가 8번과 7번 염색체의 동원체 부위에서 각각 관찰되었다. 제주황기의 경우 1쌍의 45S rDNA는 8번 염색체의 동원체 부위와 2쌍의 5D rDNA는 7번과 8번 염색체에서 각각 관찰되어 세포유전학적 차이를 보였다.

• 멤브레인
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• 제21권1호
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• pp.30-38
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• 2011

고온 무가습 조건에서 고분자 전해질 막의 수화성 및 수소이온 전도도 향상을 위해 sulfonated poly(aryl ether sulfone) 전해질 고분자에 sulfated $ZrO_2$ ($s-ZrO_2$)를 함침시킨 유-무기 복합막을 제조하였다. X-ray diffraction를 통해 $s-ZrO_2$ 의 구조적 특징과 입자크기를 확인하였으며 추가적으로 FT-IR 분석을 통해, $s-ZrO_2$입자에 술폰산기가 화학적으로 결합되어 있음을 확인 할 수 있었다. 다양한 $s-ZrO_2$ 조성비를 가진 유-무기 복합막의 이점을 확인하기 위해서 이온교환능력, 함수율, 수소이온 전도도를 측정하였다. 실험결과, $s-ZrO_2$의 조성비를 달리한 유-무기 복합막의 수소이온 전도도는, 5 wt% $s-ZrO_2$를 함유한 유-무기 복합막의 경우에서, 상온 수화조건 뿐만 아니라 $100^{\circ}C$ 이상의 무가습 조건에서 매우 높은 수소 이온 전도도를 나타내었다. 특히 $120^{\circ}C$ 무가습 조건에서도 5 wt% $s-ZrO_2$를 함유한 유-무기 복합막이 $0.0018\;S\;cm^{-1}$의 매우 높은 전도도를 나타냄으로써 $100^{\circ}C$ 이상의 고온에서도 높은 수화도를 유지하는 유-무기 복합막의 제조가 가능하였다.

• 생물환경조절학회지
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• 제8권2호
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• pp.108-114
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• 1999

식물공장에 있어서 생산성 극대화를 위한 최적환경을 구명하기 위하여, 식물공장 시스템 하에서 광도와 배양액 농도가 잎상추의 생육과 품질에 미치는 영향을 조사하였다. 실험결과 광이 높아짐에 따라 증산량과 광합성량이 높았으며, 광도 200$\mu$mol $m^{-2}$ $s^{-1}$과 300$\mu$mol $m^{-2}$ $s^{-1}$ 에서 생체중과 건물중이 가장 높게 나타났다. 따라서 식물공장내 잎상추의 최적 광도는 200 $\mu$mol $m^{-2}$ $s^{-1}$ 이상으로 나타났다. 지상부 환경요인들과의 지하부 환경 요인과의 관계를 밝히기 위해서 광도와 배양액 농도간의 관계가 잎상추 생육과 품질에 미치는 영향을 조사한 결과 통계적 유의성은 없었으나 저광도에서는 배양액농도가 높은 편인 2.4 mS cm-1에서 고광도에서는 1.8 mS cm-1 수준에서 생육량이 많게 나타났다.

• 대한수의학회지
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• 제55권3호
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• pp.191-197
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• 2015

Escherichia (E.) coli is commensal bacteria found in the intestine; however, some pathogenic strains cause diseases in animals and humans. Although E. coli does not typically produce hydrogen sulfide ($H_2S$), $H_2S$-producing strains of E. coli have been identified worldwide. The relationship between virulence and $H_2S$ production has not yet been determined. Therefore, characteristics of $H_2S$-producing isolates obtained from swine feces were evaluated including antibiotic resistance patterns, virulence gene expression, and genetic relatedness. Rates of antibiotic resistance of the $H_2S$-producing E. coli varied according to antibiotic. Only the EAST1 gene was detected as a virulence gene in five $H_2S$-producing E. coli strains. Genes conferring $H_2S$ production were not transmissible although the sseA gene encoding 3-mercaptopyruvate sulfurtransferase was detected in all $H_2S$-producing E. coli strains. Sequences of the sseA gene motif CGSVTA around Cys238 were also identical in all $H_2S$- producing E. coli strains. Diverse genetic relatedness among the isolates was observed by pulsed-field gel electrophoresis analysis. These results suggested that $H_2S$-producing E. coli strains were not derived from a specific clone and $H_2S$ production in E. coli is not associated with virulence genes.