• IMMUNE NETWORK
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• 제3권1호
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• pp.16-22
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• 2003

Background: The S100A2 gene, also known as S100L or CaN19, encodes a protein comprised of 99-amino acids, is a member of the calcium-binding proteins of EF-hand family. According to a recent study, this gene was over-expressed in several early and malignant carcinomas compared to normal tissues. To elucidate the role of S100A2 protein in the process during carcinogenesis, production of monoclonal antibody specific to the protein is essential. Methods: First, cDNA sequence coding for ORF region of human S100A2 gene was amplified and cloned into an expression vector to produce GST fusion protein. Recombinant S100A2 protein and subsequently, monoclonal antibody to the protein were produced. The specificity of anti-S100A2 monoclonal antibody was confirmed by immunoblot analysis of cross reactivity to other recombinant proteins of S100A family (GST-S100A1, GST-S100A4 and GST-S100A6). To confirm the relation of S100A2 to cervical carcinogenesis, S100A2 protein in early cervical carcinoma tissue was immunostained using the monoclonal antibody. Results: GST-S100A2 recombinant protein was purified by affinity chromatography and then fusion protein was cleaved and S100A2 protein was isolated. The monoclonal antibody (KK0723; Korean patent pending #2001-30294) to the protein was produced and the antibody did not react with other members of EF-hand family proteins such as S100A1, S100A4 and S100A6. Conclusion: These data suggest that anti-S100A2 monoclonal antibody produced in this study can be very useful for the early detection of cervical carcinoma and elucidation of mechanism during the early cervical carcinogenesis.

• 한국세라믹학회지
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• 제35권12호
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• pp.1329-1336
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• 1998

A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

• The Korean Journal of Physiology and Pharmacology
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• 제25권3호
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• pp.239-249
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• 2021

The present study explored the therapeutic potential of hydrogen sulfide (H2S) in restoring aging-induced loss of cardioprotective effect of remote ischemic preconditioning (RIPC) along with the involvement of signaling pathways. The left hind limb was subjected to four short cycles of ischemia and reperfusion (IR) in young and aged male rats to induce RIPC. The hearts were subjected to IR injury on the Langendorff apparatus after 24 h of RIPC. The measurement of lactate dehydrogenase, creatine kinase and cardiac troponin served to assess the myocardial injury. The levels of H2S, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), nuclear factor erythroid 2-related factor 2 (Nrf2), and hypoxia-inducible factor (HIF-1α) were also measured. There was a decrease in cardioprotection in RIPC-subjected old rats in comparison to young rats along with a reduction in the myocardial levels of H2S, CBS, CSE, HIF-1α, and nuclear: cytoplasmic Nrf2 ratio. Supplementation with sodium hydrogen sulfide (NaHS, an H2S donor) and l-cysteine (H2S precursor) restored the cardioprotective actions of RIPC in old hearts. It increased the levels of H2S, HIF-1α, and Nrf2 ratio without affecting CBS and CSE. YC-1 (HIF-1α antagonist) abolished the effects of NaHS and l-cysteine in RIPC-subjected old rats by decreasing the Nrf2 ratio and HIF-1α levels, without altering H2S. The late phase of cardioprotection of RIPC involves an increase in the activity of H2S biosynthetic enzymes, which increases the levels of H2S to upregulate HIF-1α and Nrf2. H2S has the potential to restore aging-induced loss of cardioprotective effects of RIPC by upregulating HIF-1α/Nrf2 signaling.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.159.2-159.2
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• 2014

간접띠간격(indirect bandgap)을 갖는 층상형 반도체 $MoS_2$는 두께가 줄어들어 단일층이 되면 층간 상호작용의 변화로 인해 ~1.8 eV의 직접띠간격(direct bandgap)을 갖게 된다. 이러한 초박형 $MoS_2$의 발광 특성을 활용하기 위해서는 원자 크기 수준에서 두께와 물성을 조절할 수 있는 화학적 표면개질법에 대한 이해가 필요하다. 최근 아르곤(Ar) 플라즈마를 이용한 $MoS_2$의 층상(layer-by-layer) 식각과 표면제어에 관한 연구결과가 보고되었으나 자세한 반응 메커니즘은 알려져 있지 않다. 본 연구에서는 산소 플라즈마에 의한 단일층 및 복층 $MoS_2$의 산화반응을 원자힘 현미경(AFM), 광전자 분광법(XPS), 라만 및 광발광 분광법을 통해 관찰하고 반응 메커니즘을 이해하고자 한다. 플라즈마로 생성된 산소라디칼과의 반응시간이 증가함에 따라 $E{^1}_{2g}$와 $A_{1g}$-진동모드에서 기인하는 라만 신호, 그리고 A와 B-엑시톤에서 유래하는 광발광의 세기가 감소함을 확인하였다. XPS와 AFM을 통해 반응이 진행됨에 따라 $MoS_2$의 상층이 $MoO_3$로 산화되면서 나노입자로 응집되어 표면형태가 변화하는 것을 확인하였다. 이 결과는 플라즈마 산화반응을 이용하여 $MoS_2$ 표면에 구조적 결함(defect)과 층상 식각을 유발하고 광발광 특성 제어를 위해 전자구조를 조절할 수 있다는 가능성을 보여준다.

• 한국재료학회지
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• 제16권7호
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• pp.455-459
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• 2006

Coincidence Doppler Broadening (CDB) of positron annihilation spectroscopy was applied to analyze defects in the chemical state of Department of Physics, $Gd_2O_2S$:Tb intensifying screens. The screen samples were irradiated by 80 MV X-rays in hospital and were used for 0, 2, 4, and 6 years respectively. There was a positive relationship between the S-parameter values and time of exposure to X-rays. Most of the defects were indicated to have been generated by X-rays. A 1D CDB was developed in order to reduce the background noise, and the S-parameter values of the $Gd_2O_2S$:Tb intensifying screens, using the 1D CDB, varied between 0.4974 and 0.4991.

• Bulletin of the Korean Chemical Society
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• 제4권2호
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• pp.92-95
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• 1983

The addition products of glutathione to ${\beta}$ -nitrostyrene derivatives were synthesized. ${\beta}$ -Nitrostyrene (1a), p-methyl-${\beta}$-nitrostyrene (1b), 3,4,5-trimethoxy-${\beta}$-nitrostyrene (1c), o-, m- and p-chloro-${\beta}$-nitrostyrene (1e, 1f, 1g) and o-, m- and p-methoxy-${\beta}$-nitrostyrene (1h, 1i, 1j) undergo addition reactions with glutathione to form S-(2-nitro-1-phenylethyl)-L-glutathione (5a), S-[2-nitro-1-(p-methyl)phenylethyl]-L-glutatione (5b), S-[2-nitro-1-(3', 4', 5'-trimethoxy)phenylethyl]-L-glutathione (5c), S-[2-nitro-1-(o-chloro)phenylethyl]-L-glutathione (5e), S-[2-nitro-1-(m-choro)phenylethyl]-L-glutathione (5f), S-[2-nitro-1-(p-chloro)phenylethyl]-L-glutathione (5g), S-[2-nitro-x-(o-methoxy)-phenylethyl]-L-glutathion e(5h), S-[2-nitro-x-(m-methoxy)phenylethyl]-L-glutathion e (5i), and S-[2-nitro-1-(p-methoxy)phenylethy])-L-glutathione (5j), respectively. The structure of adducts were identified by UV and IR-spectra, molecular weight measurement, and elemental analysis.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1550-1554
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• 2008

A hydrogen sulfide $(H_2S)$ detecting tube was developed for the quantitative determination of $H_2S$ produced by yeast during laboratory scale wine fermentations. The detecting tube consisted of a small transparent plastic tube packed with an $H_2S$-sensitive color-indicating medium. The packed medium changed color, with the color change progressing upward from the bottom of the tube, upon exposure to $H_2S$ produced by yeast during fermentation. A calibration study using a standard $H_2S$ gas showed that the length of the portion that darkened was directly related to the quantity of $H_2S$ (${\mu}g$) with a high correlation coefficient ($r^2$=0.9997). The reproducibility of the $H_2S$ detecting tubes was determined with five repetitive measurements using a standard $H_2S$ solution [5.6${\mu}g$/200 ml (28 ppb)], which resulted in a coefficient of variation of 3.6% at this level of $H_2S$. With the sulfide detecting tubes, the production of $H_2S$ was continuously monitored and quantified from laboratory scale wine fermentations with different yeast strains and with the addition of different levels of elemental sulfur to the grape juice. This sulfide detecting tube technology may allow winemakers to quantitatively measure $H_2S$ produced under different fermentation conditions, which will eventually lead winemakers to better understand the specific factors and conditions for the excessive production of $H_2S$ during wine fermentation in a large production scale.

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2533-2536
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• 2008

• 대한전기학회논문지
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• 제41권5호
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• pp.517-524
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• 1992

In this study, 0.10Pb(SbS11/2TSnS11/2T)OS13T-(0.90-x)PbZrOS13T (0.25 x 0.40) ceramics were fabricated by the atmospheric method. The sintering temperature and time were 1250[$^{\circ}C$] and 2[2hr], respectively. The structureal, dielectric and piezoelectric properties with composition of PbTiOS13T were studied. As the results of XRD ans SEM, the crystal structure of a specimen was rhombohedral, lattice constant and average grain size were decreased with increasing the contents of PbTiOS13T. Relative dielectric constant and Curie temperature were increased with increasing the contents of PbTiOS13T, 0.10PSS-0.40PT-0.50PZ specimen had the highest values of 904 and 265[$^{\circ}C$], respectively. In increasing of PbTiOS13T contents form 25[mol%] to 40[mol%], piezoelectric charge constant and electromechanical coupling factors were increased form 114[pC/N] to 142[pC/N], 17[%] to 24[%] and mechanical quality factor were decreased with increasing the contents of PbTiOS13T. In the 0.10PSS-0.40PT-0.50PZ specimens, those values were 14.2[kV/cm] and 9.43[x10S0-6TC/cmS02T], resectively.

• 한국진공학회지
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• 제6권1호
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• pp.50-60
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• 1997

순수한 $ZnAl_2S_4,;ZnAl_2Se_4,;CdAl_2S_4,;and;CdAl_2Se_4$ 및 cobalt와 erbium을 불순물로 첨가 한 이들 단결정을 화학수송법으로 성장시켰다. 성장된 단결정의 결정구조, 격자상수, 광학적 energy gap, photoluminescence 특성 등을 측정하여 광학적 전이 기구를 규명하였다.