• Journal of the Korean Ceramic Society
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• v.24 no.2
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• pp.186-192
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• 1987

ZrO2 powders having high purity were prepared from domestic zircon sand using the caustic fusion method and the soda ash sintering process. In the caustic fusion method, ZrO2 recovery was reached to 96% when 100/140 mesh zircon was reacted with NaOH at the NaOH/Zircon mole ratio 6 and at 650$^{\circ}C$ for 2 hours. And in the soda ash sintering process, ZrO2 was recovered to 88.5% when -325 mesh zircon was reacted with Na2CO3 at the Na2CO3/Zircon mole ratio 1.1 and 1050$^{\circ}C$ for 2 hours. In both cases, Zr component was extracted to ZrOCl2, subsequently crystallized to ZrOCl2$.$8H2O to increase the purity, and converted to ZrO2 by precipitation. And to increase the sinter ability of powder, Cl- ion was removed and strong agglomeration was avoided by methanol distribution of Zr(OH)4 precipitates.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.426-432
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• 2016

Age-related rotator cuff tendon degeneration is related to tenofibroblast apoptosis. Anthocyanins reduce oxidative stress-induced apoptotic cell death in tenofibroblasts. The current study investigated the presence of cell protective effects in cyanidin and delphinidin, the most common aglycon forms of anthocyanins. We determined whether these anthocyanidins have antiapoptotic and antinecrotic effects in tenofibroblasts exposed to $H_2O_2$, and evaluated their biomolecular mechanisms. Both cyanidin and delphinidin inhibited $H_2O_2$-induced apoptosis in a dose-dependent manner. However, at concentrations of $100{\mu}g/ml$ or greater, delphinidin showed cytotoxicity against tenofibroblasts and a decreased antinecrotic effect. Cyanidin and delphinidin both showed inhibitory effects on the $H_2O_2$-induced increase in intracellular ROS formation and the activation of ERK1/2 and JNK. In conclusion, both cyanidin and delphinidin have cytoprotective effects on cultured tenofibroblasts exposed to $H_2O_2$. These results suggest that cyanidin and delphinidin are both beneficial for the treatment of oxidative stress-mediated tenofibroblast cell death, but their working concentrations are different.

• Korean Journal of Crystallography
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• v.4 no.1
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• pp.1-5
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• 1993

The crystal structure of N-(2'-chloro-4'-vitrophenyl)-5-chlorosalicylamide( Niclosamide ) monohydrate has been determined from 1976 sig- nificant independent reflections collected on an automated CAD4 diffractometer using graphitemonochromated Mo-Ka radiation. The crystal is monoclinic, space group P211c, with unit cell dimensions, a=11.331 (3), b=16.964(2), c=7.347(4)A , P =98.20(3)° and Z=4 at T=293k. The structure was solved by direct method using seminvariants of ggg Parity group and refined by the full-matrix least-square method, resulting model with reliability factor, R=0.046. The feature of the molecule show planar structure in parallel to the ab crystal plane.

• Herbal Formula Science
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• v.12 no.2
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• pp.155-162
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• 2004

The purpose of this study is to examine the protective effect of Cynomorii herba on $H_2O_2$-induced cytotoxicity in male germ cells. The effects were studied by a modified MTT assay. Hydrogen peroxide significantly induced cytotoxicity in GC-1 spg cells, and co-treatment or pre-treatment of Cynomorii herba extract has reduced the cytotoxicity in a dose dependant manner. These results suggest that Cynomorii herba extract increases the survival rate of GC-1 spg cells through the antioxidant effect against $H_2O_2$-induced cytotoxicity.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.155-158
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• 2000

Production of decursinol angelate, a new potential anticancer agent, in Angelica gigas Nakai root culture was increased by treatment of $H_2O_2$, and various polysaccharides such as $CM-\;{\beta}\;-cyclodextrin$, glucan, $CM-\;{\beta}\;-chitin$, yeast extract and pectin. One mmole $H_2O_2$ enhanced the production of decursinol angelate. However, higher concentrations of $H_2O_2$ were founded to be toxic for root growth whereas specific productivity of decursinol angelate was increased at high concentrations of $H_2O_2$. In the case of polysaccharide elicitors, $CM-\;{\beta}\;-chitin$ was the most effective for enhanced production of secondary metabolite in A. gigas Nakai root culture.

• Journal of Electrochemical Science and Technology
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• v.9 no.2
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• pp.133-140
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• 2018

$Sr_{0.92}Y_{0.08}Ti_{0.5}Fe_{0.5}O_{3-{\delta}}$ (SYTF0.5) is investigated as an alternative anode in $H_2$ fuels containing $H_2S$ (0-200 ppm). Although additional ionic conductivity is introduced by aliovalent substitution of $Ti^{4+}$ by $Fe^{3+}$ in the B-site, the SYTF0.5 has lower electrical conductivity than that of the $Sr_{0.92}Y_{0.08}TiO_{3-{\delta}}$. Due to the mixed ionic and electronic conductive (MIEC) property exhibited in the SYTF0.5 anode, the electrochemical performance of the SYTF0.5 anode is improved, as well as the sulfur tolerance. The maximum power densities in $H_2$ at $900^{\circ}C$ for the SYT anode and the SYTF0.5 anode were 56.9 and $98.6mW/cm^2$, respectively. The maximum power density in the SYTF0.5 anode at 200 ppm of $H_2S$ concentration decreased by only 12.9% (86.3 to $75.2mW/cm^2$).

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.24-31
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• 2010

Taurine, 2-aminoethanesulfonic acid, is an abundant free amino acid present in brain cells and exerts many important biological functions such as anti-convulsant, modulation of neuronal excitability, regulation of learning and memory, anti-aggressiveness and anti-alcoholic effects. In the present study, we investigated to explore whether taurine has any protective actions against oxidative stress-induced damages in neuronal cells. ERK I/II regulates signaling pathways involved in nitric oxide (NO) and reactive oxygen species (ROS) production and plays a role in the regulation of cell growth, and apoptosis. We have found that taurine significantly inhibited AMPA induced cortical depolarization in the Grease Gap assays using rat cortical slices. Taurine also inhibited AMPA-induced neuronal cell damage in MTT assays in the differentiated SH-SY5Y cells. When the neuronal cells were treated with $H_2O_2$, levels of NO were increased; however, taurine pretreatment decreased the NO production induced by $H_2O_2$ to approximately normal levels. Interestingly, taurine treatment stimulated ERK I/II activity in the presence of AMPA or $H_2O_2$, suggesting the potential role of ERK I/II in the neuroprotection of taurine. Taken together, taurine has significant neuroprotective actions against AMPA or $H_2O_2$ induced damages in neuronal cells, possibly via activation of ERK I/II.

• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.353-356
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• 1973

A unique method of destructive analysis has been developed for the study of gaseous impurities in minerals. Samples are crushed in a high vacuum sample system of a research mass spectrometer. This is done by means of a suitably designed crusher which is incorporated in the inlet system of the instrument. Crusher elements are constructed of tungsten carbide. The mass spectrometer used for this preliminary study has a detection sensitivity of about $10^{-10}cc$at STP. In a study of rhodolite garnets obtained from near Lavonia, Georgia, U.S.A., the gases$H_2$, $O_2$, $H_{2}O$, $CO_2$, CO, and $CH_4$have been identified and their composition determined.

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.144-148
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• 1997

the molecular and crystal 3-dimensional structure of bentazone, C10H12N2O3S, has been determined from single crystal x-ray diffraction study. Crystal system is monoclinic: a=8.7817(9)Å, b=9.6059(9) Å, c=13.574(9) Å, β=97.269(1)', V=1136.1(6)Å, space group : P21/c, z=4. The molecular structure model was solved by direct method and refined by full matrix least squares. The final reliable factor, R, is 0.045 for 1396 independent reflections(Fo2>4σFo2). A molecule has a staggered conformation with thiocarbazin ring and isopropyl functional group and the molecules by hydrogen bonds are cross stacked along the c-axis.

• Journal of Surface Science and Engineering
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• v.38 no.3
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• pp.118-125
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• 2005

Low temperature plasma treatment with different gases and rf powers were performed to improve the adhesion strength between polytetrafluoroethylene(PTFE) and electroless deposited copper. According to the research, $H_2$ plasma having hydrogen radical was more effective in surface polarity modification than $O_2$ plasma due to the defluorination reaction. However, surface roughness of PTFE was more increased with $O_2$ than $H_2$ plasma. PTFE treated with $120W-O_2$ plasma and $250w-H_2$ plasma, consecutively showed rougher surface than single step $250w-H_2$ plasma treated one and more hydrophilic than single step $120W-O_2$ plasma treated one. And it showed 5B tape test grade, which is better adhesion property than 1B or 3B obtained by single step plasma treatment. In addition, adhesion strength between PTFE and Cu deposit is also deeply affected by residual water on its interface.