• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.859-866
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• 2003

When calcium sulfoaluminate-based expansive cement was hydrated, ettringite and monosulfate were mainly formed. The crack of hardened cement was prevented by compensating drying shrinkage due to formation of the above hydrates. In order to study the hydration properties of calcium sulfoaluminate-based expanding cement, 3CaOㆍ3Al$_2$O$_3$ㆍCaSO$_4$(C$_4$A$_3$S) was prepared by chemical synthesis, and then the hydration of $C_4$A$_3$S-Ca(OH)$_2$-CaSO$_4$.$2H_2O$-C$_3$A system_was characterized. Good $C_4$A$_3$S phase was prepared at $1300^{\circ}C$ by chemical synthesis, and the main hydration product of $C_4$A$_3$S-Ca(OH)$_2$-CaSO$_4$.2$H_2O$ system was ettringite. In the case of hydration $C_4$A$_3$S-Ca(OH)$_2$-CaSO$_4$ㆍ 2$H_2O$-C$_3$A system, ettringite was formed in the early period and it was transformed into monosulfate while consumed gypsum.

• Journal of the Korean Ceramic Society
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• v.47 no.2
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• pp.183-188
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• 2010

$Ce_{0.8}Gd_{0.2}O_{1.9}$(GDC20) powder was synthesized by milling of $CeO_2$ slurry and Gd oxalate precipitation. The mixture of $CeO_2$ powder and Gd precipitates calcined at $600^{\circ}C$ for 2 h showed the particle size distribution similar to that of $CeO_2$ powder, which had been milled during the synthesis process. Attrition milling of the calcined powder with an average particle size of $0.36\;{\mu}m$ for 2 h resulted in a decrease in the particle size to $0.24\;{\mu}m$. Although the milled powder consisted of small particles(<$1\;{\mu}m$), a small amount of fine platy $Gd_2O_3$ particles, which had been survived in the milling process, was observed. Sintering of the powder compacts for 4 h showed relative densities of 80.7% at $1300^{\circ}C$ and 97% at $1400^{\circ}C$, respectively. Densification was found to almost complete at $1500^{\circ}C$, resulting in a dense and homogeneous microstructure with a relative density of 99.5%.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.59-67
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• 2018

This study was conducted to isolate the cellulolytic bacteria able to grow on LB- Carboxymethyl cellulose (CMC) agar trypan blue medium from the mixed forest and Larix leptolepis stands. Three bacterial strains with high activity against both CMC and xylan were isolated. Both API kit test and 16S rRNA gene sequence analysis revealed that the three different isolates belong to the gene Bacillus. Therefore, the isolates named as Bacillus sp. EFL1, Bacillus sp. EFL2, and Bacillus sp. EFP3. The optimum growth temperature of Bacillus sp. EFL1, EFL2, and EFP3 were $37^{\circ}C$. The optimum temperature for CMCase and xylanase from Bacillus sp. EFL1 were $50^{\circ}C$. The optimum pH of Bacillus sp. EFL1 xylanase was pH 5.0 but the optimum pH of CMCase from Bacillus sp. EFL1 was pH 6.0. The optimum temperature of CMCase and xylanase from Bacillus sp. EFL2 was $60^{\circ}C$, respectively. The optimum pH of CMCase of Bacillus sp. EFL2 was 5.0, whereas xylanase showed high activity at pH 3.0-9.0. The optimum temperature for CMCase and xylanase of Bacillus sp. EFP3 was $50^{\circ}C$. The optimum pH for CMCase and xylanse was 5.0 and 4.0, respectively. CMCases from Bacillus sp. EFL1, EFL2, and EFP3 were thermally unstable. Although xylanase from Bacillus sp. EFL1 and EFP3 showed to be thermally unstable, xylanase from Bacillus sp. EFL2 showed to be thermally stable. Therefore, Bacillus sp. EFL2 has great potential for animal feed, biofuels, and food industry applications.

• Journal of Ginseng Research
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• v.44 no.2
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• pp.258-266
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• 2020

Background: Oxidative stress-induced cardiomyocytes apoptosis is a key pathological process in ischemic heart disease. Glutathione reductase (GR) reduces glutathione disulfide to glutathione (GSH) to alleviate oxidative stress. Ginsenoside Rb1 (GRb1) prevents the apoptosis of cardiomyocytes; however, the role of GR in this process is unclear. Therefore, the effects of GRb1 on GR were investigated in this study. Methods: The antiapoptotic effects of GRb1 were evaluated in H9C2 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, annexin V/propidium iodide staining, and Western blotting. The antioxidative effects were measured by a reactive oxygen species assay, and GSH levels and GR activity were examined in the presence and absence of the GR inhibitor 1,3-bis-(2-chloroethyl)-1-nitrosourea. Molecular docking and molecular dynamics simulations were used to investigate the binding of GRb1 to GR. The direct influence of GRb1 on GR was confirmed by recombinant human GR protein. Results: GRb1 pretreatment caused dose-dependent inhibition of tert-butyl hydroperoxide-induced cell apoptosis, at a level comparable to that of the positive control N-acetyl-L-cysteine. The binding energy between GRb1 and GR was positive (-6.426 kcal/mol), and the binding was stable. GRb1 significantl reduced reactive oxygen species production and increased GSH level and GR activity without altering GR protein expression in H9C2 cells. Moreover, GRb1 enhanced the recombinant human GR protein activity in vitro, with a half-maximal effective concentration of ≈2.317 μM. Conversely, 1,3-bis-(2-chloroethyl)-1-nitrosourea co-treatment significantly abolished the GRb1's apoptotic and antioxidative effects of GRb1 in H9C2 cells. Conclusion: GRb1 is a potential natural GR agonist that protects against oxidative stress-induced apoptosis of H9C2 cells.

• Journal of Embryo Transfer
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• v.19 no.1
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• pp.11-18
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• 2004

The aim of this study was to evaluate the improvement of testicular sperm motility following different culture conditions such as human follicular fluid (hFF) and temperature. Testicular tissues obtained from azoospermia (n=21) were minced into small pieces by blade and recovered sperm suspension were cultured in Ham's F10 with or without 40% hFF at different temperatures (Group I: 37$^{\circ}C$/with hFF, Group II: 32$^{\circ}C$/withGroup III: 37$^{\circ}C$/without, Group IV:32$^{\circ}C$ /without The motility and viability of sperm were monitored during culture for 48 hours. Initial motility of testicular sperm was 10.9$\pm$1.9%. After 24 hours culture, sperm motility was 23.5$\pm$2.1% (Group I), 8.1$\pm$1.1% (Group II), 10.4$\pm$ 1.4% (Group III) and 4.0$\pm$0.8% (Group IV), respectively. After 48 hours, the motility had been changed as 32$\pm$2.3% (Group I), 14.3$\pm$1.7% (Group II), 5.3 $\pm$1.4% (Group III) and 4.3$\pm$0.9% (Group IV). In hFF group (I and II), sperm motility of group I cultured at 37$^{\circ}C$ was higher than those of group II at 32$^{\circ}C$. But, sperm viability of group I cultured at 37$^{\circ}C$ was lower than those of group II at 32$^{\circ}C$ (54.4$\pm$4.1% vs. 59.4$\pm$3.7%) after cultured for 48 hours. We acquired the best motility of testicular sperm when performed in vitro culture for 48 hours in hFF supplemented medium at 37$^{\circ}C$. Increase of sperm motility by in vitro culture could be useful tool fur human TESE-ICSI program.

• Bulletin of the Korean Chemical Society
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• v.16 no.9
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• pp.835-839
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• 1995

Mer,trans-Re(≡NC6H5)(PPh3)2Cl3, Ⅰ, reacted with trimethylphosphine to give a mixture of two stereoisomers, mer,trans-Re(≡NC6H5)(PMe3)2Cl3,Ⅱ, and fac,cis-Re(≡NC6H5)(PMe3)2Cl3, Ⅲ. These compounds could also be prepared from the reaction of Re(≡NC6H5)(PMe3)(PPh3)Cl3 with trimethylphosphine. In both reactions the mer,trans-isomer is a major product. The products have been characterized by NMR, elemental analysis, and X-ray crystallography. Crystal data for Ⅱ: monoclinic space group P21, a=10.053(1) Å, b=10.844(1) Å, c=10.058(2) Å, β=113.45(2)°, Z=2, R(wR2)=0.0348 (0.0894). Crystal data for Ⅲ: monoclinic space group P21/n, a=7.183(2) Å, b=16.983(4) Å, c=15.543(4) Å, β=90.38(2)°, Z=4, R(wR2)=0.0603 (0.1484).

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.683-689
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• 2003

The cylindrical ${\gamma}$-alumina pellets were prepared using amorphous alumina and pore generating agent. Its were immersed in aqueous solution of the mixture of Fe(NO$_3$)$_3$.9$H_2O$ and $CH_3$COOH, Fe(NO$_3$)$_3$.9$H_2O$ and $CH_3$COOH and HNO$_3$, and Fe(NO$_3$)$_3$.9$H_2O$ and HNO$_3$. The pellets thus were hydrothermally treated at 20$0^{\circ}C$ for 3 h in autoclave, and were investigated morphologies and changes of crystal pore characteristics, $N_2$ adsorption and desorption isotherms, active sites and mechanical strength etc. According to the preparation method, acicular platelet pseudo-boehmite crystals of 0.1~0.3 ${\mu}{\textrm}{m}$ size were transformed into acicular pseudo-boehmite cristals of 0.5~2 ${\mu}{\textrm}{m}$ size having the same crystal structure. When ${\gamma}$-alumina pellets were immersed in aqueous solution of the mixture of Fe(NO$_3$)$_3$.9$H_2O$ and $CH_3$COOH and then were hydrothermally treated, pore volume between 100 $\AA$ and 1000 $\AA$ was increased from 0.34 ㏄/g to 0.86 ㏄/g, and the gap of $N_2$ adsorption and desorption hysteresis loop was decreased due to increasement of pore size. New active site that could adsorb the C-H functional group was created on the catalist. Also, mechanical strength of catalyst was increased from 1.06 ㎫ to 1.36 ㎫.

• Transactions on Electrical and Electronic Materials
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• v.9 no.2
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• pp.73-78
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• 2008

We investigated for comparison of large-area i-a-Si:H and p-a-SiC:H film quality like thickness uniformity, optical bandgap and surface roughness using both ICP-CVD and PECVD on the large-area substrate(diameter of 100 mm). As a whole, films using ICP-CVD could be achieved much uniform thickness and bandgap of that using PECVD. For i-a-Si:H films, its uniformity of thickness and optical bandgap were 2.8 % and 0.38 %, respectively. Also, thickness and optical bandgap of p-a-SiC:H films using ICP-CVD could be obtained at 1.8 % and 0.3 %, respectively. In case of surface roughness, average surface roughness (below 5 nm) of ICP-CVD film could be much better than that (below 30 nm) of PECVD film. HIT solar cell with 2 wt%-AZO/p-a-SiC:H/i-a-Si:H/c-Si/Ag structure was fabricated and characterized with diameter of 152.3 mm in this large-area ICP-CVD system. Conversion efficiency of 9.123 % was achieved with a practical area of $100\;mm\;{\times}\;100\;mm$, which can show the potential to fabrication of the large-area solar cell using ICP-CVD method.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.178-182
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• 1983

The conductances of sodium, potassium, ammonium, tetramethylammonium, and tetraethylammonium iodides, picrates(Pic) of sodium and potassium, and tetrabutylammonium tetraphenyl-boride have been measured in ethylene carbonate-acetone mixtures at $25{\circ}C$. The limiting equivalent conductances of the electolytes were computed by Fuoss-Kraus equation and the order was $(C_4H_9)_4NB(ph)_4 at any composition of the mixtures. The dissociation constants of the salts showed that the mixtures are good ionizing solvents for the salts. The order of limiting ionic equivalent conductance, $Na^+, is consistent with exactly the reverse order found for solvation number. Effective solvated radii calibrated by the Nightingale method showed that picrate ion seems to be unsolvated and that iodide ion seems to be solvated to some extent in the mixtures.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.163-176
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• 2012

TTo increase productivity of a strong extracellular alkaline protease (BCAP), stable strains of Bacillus clausii I-52 carrying another copy of BCAP gene in the chromosome were developed. Integrative vector, pHPS9-fuBCAP carrying BCAP promoter, ribosome binding site, signal sequence and active protease gene was constructed and transferred into B. clausii I-52, and integration of the constructed plasmid into chromosome was identified by PCR. An investigation was carried out on BCAP production by B. clausii I-52 and transformant C5 showing the highest relative activity of alkaline protease using submerged fermentation. Maximum enzyme activity was produced when cells were grown under the submerged fermentation conditions at $37^{\circ}C$ for 48 h with an aeration rate of 1 vvm and agitation rate of 650 rpm in a optimized medium (soybean meal 2%, wheat flour 1%, sodium citrate 0.5%, $K_2HPO_4$ 0.4%, $Na_2HPO_4$ 0.1%, NaCl 0.4%, $MgSO_47H_2O$ 0.01%, $FeSO_47H_2O$ 0.05%, liquid maltose 2.5%, $Na_2CO_3$ 0.6%). A protease yield of approximately 134,670U/ml was achieved using an optimized media, which show an increase of approximately 1.6-fold compared to that of non-transformant (83,960 U/ml). When the stability of transformant C5 was examined, the integrated plasmid pHPS9-fuBCAP was detected in the transformant after cultivation for 8 days, suggesting that it maintained stably in the chromosomal DNA of transformant C5.