• Journal of Life Science
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• v.24 no.10
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• pp.1046-1054
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• 2014

Beta-1,3-glucanase is widely used in various biotechnological and industrial processes, with over-production required to enable versatile utilization. We examined the overexpression of ${\beta}$-1,3-glucanase (EXGA) from Aspergillus oryzae using ${\delta}$-sequence-mediated integration. We constructed $pRS{\delta}$-exgA and $pRS{\delta}K$-exgA plasmids for integration of the EXGA gene into various chromosomes of Saccharomyces cerevisiae. These plasmids contain the ADH1 promoter for constitutive expression, a signal sequence (exoinulinase signal sequence [INU1 s.s]) for secretory production, and a ${\delta}$-sequence for integration of ${\beta}$-1,3-glucanase. The $pRS{\delta}$-exgA plasmid was transformed into the S. cerevisiae $BY4742{\Delta}exg1$ strain, and ${\beta}$-1.3-glucanase was stably overexpressed and secreted. Another plasmid, $pRS{\delta}K$-exgA, was introduced into the S. cerevisiae $BY4742{\Delta}exg1$ (YKY082) strain, and overexpression of ${\beta}$-1,3-glucanase was examined by inducible integration under geneticin selection. The activity of ${\beta}$-1,3-glucanase increased in accordance with a rise in the geneticin concentration, with 0.8 mg/ml of geneticin suitable for overexpression of ${\beta}$-1,3-glucanase. Subsequently, $pRS{\delta}K$-exgA was repeatedly transformed for sequential ${\delta}$-integration. The activity of ${\beta}$-1,3-glucanase reached about 0.063 unit/ml/$OD_{600}$, 0.095 unit/ml/$OD_{600}$, 0.131 unit/ml/$OD_{600}$ and 0.165 unit/ml/$OD_{600}$ by the first, second, third, and fourth round of integration, respectively. According to the increase in the activity of ${\beta}$-1,3-glucanase by sequential ${\delta}$-integration, the copy number (integration rate) of the EXGA gene also increased in various chromosomes. These results suggest that recombinant ${\beta}$-1,3-glucanase activity can be sequentially increased by repeated ${\delta}$-sequence integration.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.244-249
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• 2011

This in vitro study compared the remineralization of incipient interproximal caries in the presence of three glass ionomer cements(highly-filled glass ionomer cement, resin-modified glass ionomer cement, compomer) and a resin composite(control). Thirty-two extracted premolars were selected based upon the lack of any visible demineralization. The teeth were coated in a transparent acid resistant nail varnish leaving $3{\times}3$ mm square. The teeth were subjected to the demineralizing buffer for 3 days and quantitative light-induced fluorescence(QLF) images of the subjects were taken. Proximal restoration was simulated by placing tooth specimens and the various glass ionomer cements in closed containers with artificial saliva at $37^{\circ}C$ and pH 7.0 with constant circulation. Further QLF images were subsequently taken at 30, 60, and 90 days. The changes of mineral loss(${\Delta}Q$) were evaluated by QLF and the change of ${\Delta}Q$(${\Delta}{\Delta}Q$) were compared between groups in order to evaluate the effects of remineralization. All data were analyzed using ANOVA and the post-HOC Dunnett C multiple comparison test at p<0.05. While ${\Delta}Q$(changes of mineral loss) increased for all treatments, the increases for three glass ionomer groups were significantly higher than that for the resin group at first month period. As time went on, the amount of ${\Delta}{\Delta}Q$ decreased.

• Journal of the Chungcheong Mathematical Society
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• v.11 no.1
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• pp.27-34
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• 1998

We introduce ${\delta}$-frames, strong ${\delta}$-frames and completely distributive lattices, and investigate some relationships among those frames.

• Proceedings of the Korean Magnestics Society Conference
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• 1998.05a
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• pp.66-67
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• 1998

• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.177-183
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• 2000

The interaction of phenoxide anion with .the mixed micelles of CTAB(Cetyl-trimethylammonium bromide) and TTAB(Tetradecyltrimethylammonium bromide) was studied by UV/Vis spectrophotometric method. The solubilization constants($K_s$) of phenoxide anion into the mixed micellar phase and the critical micellar concentrations(CMC) of those mixed surfactant systems have been measured and analyzed with the change of overall mole fraction of CTAB($\alpha_{CTAB}$) The effects of additives(n-pentanol and NaBr) on the solubilization of phenoxide anion by those mixed surfactant systems have been also measured. There was a great decrease on the values of solubilization constant and CMC with these additives. For the thermodynamic study, the dependence of $K_s$ values on temperature has been measured and various thermodynamic parameters(${\Delta}G^0_s$, ${\Delta}H^0_s$ and ${\Delta}S^0_s$) have been also calculated. The results show that all the values of ${\Delta}G^0_s$ and ${\Delta}H^0_s$ are negative within the measured temperature region but the values of ${\Delta}S^0_s$ are positive.

• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.301-306
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• 1986

The rate constants for the solvolysis reactions of p-methoxybenzylchloride in ethanol-water mixtures were determined at 2$^{\circ}$ and 10$^{\circ}C$ up to 1600bar. Rates of reaction were increased with increasing temperature and pressure, and decreased with increasing solvent composition of ethanol mole fraction. From the rate constants, the values of the activation parameters (${{\Delta}V_o}^{\neq},\;{\Delta}{\beta}^{\neq},\;{\Delta}H^{\neq},\;and\;{\Delta}S^{\neq}$) were evaluated. The values of ${{\Delta}V_o}^{\neq}$ and ${\Delta}{\beta}^{\neq}$ exhibit the extremum behavior at about 0.30 mole fraction of ethanol. This behavior is discussed in terms of solvent structure variation. From these results, it could be postulated that the reaction proceeds through $S_N1$ mechanism.

• Journal of the Korea Society of Computer and Information
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• v.17 no.11
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• pp.189-196
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• 2012

This paper proposes Swap algorithm for solving Dynamic Economic Dispatch (DED) problem. The proposed algorithm initially balances total load demand $P_d$ with total generation ${\Sigma}P_i$ by deactivating a generator with the highest unit generation cost $C_i^{max}/P_i^{max}$. It then swaps generation level $P_i=P_i{\pm}{\Delta}$, (${\Delta}$=1.0, 0.1, 0.01, 0.001) for $P_i=P_i-{\Delta}$, $P_j=P_j+{\Delta}$ provided that $_{max}[F(P_i)-F(P_i-{\Delta})]$ > $_{min}[F(P_j+{\Delta})-F(P_j)]$, $i{\neq}j$. This new algorithm is applied and tested to the experimental data of Dynamic Economic Dispatch problem, demonstrating a considerable reduction in the prevalent heuristic algorithm's optimal generation cost and in the maximization of economic profit.

• Journal of the Korean Chemical Society
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• v.58 no.6
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• pp.517-523
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• 2014

The micellization of TTAB(tetradecyltrimethylammonium bromide) and the solubilization of 4-halogenated phenol isomers in aqueous solution of that surfactant in water have been studied by the UV-Vis spectrophotometric method. Those properties in aqueous solutions of NaCl and n-butanol have been also measured to determine the interactions between the micelle and 4-halogenated phenols and the solubilized sites of those molecules in the micelle. The results show that the values of ${\Delta}G^o_m$ and ${\Delta}G^o_s$ are all negative and the trends of those values depend on both the kinds and the concentrations of additives. Namely, by adding NaCl both ${\Delta}G^o_m$ and ${\Delta}G^o_s$ values are all decreasing, but by adding n-butanol the ${\Delta}G^o_m$ value decreases and the ${\Delta}G^o_s$ value increases.

• The Journal of Engineering Geology
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• v.12 no.3
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• pp.285-294
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• 2002

The origin of nitrate in confined groundwater was studied using oxygen ($\delta$180), hydrogen ($\delta$D), and nitrogen ($\delta$15N) stable isotopes, along with chemical data of NO3-N. We analyzed groundwaters from more than sixty manufactories producing natural mineral waters around the country During the period of 1998-2001, an average value of nitrate was fair]y low (0.95 mg/$\ell$), however, groundwaters from six sites showed more than 2 mg/$\ell$ of nitrate. The stable isotope data of the groundwaters are -8.3~-11 $\textperthousand$ $\delta$8O, -60~-75 $\textperthousand$ $\delta$D, which lies in an average range of the groundwaters. The nitrogen isotope data with -11.8~-5.1$\textperthousand$ $\delta$15N suggest that manure, organic nitrate, and fertilizers can not be the origin of nitrate in the goundwaters.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.697-702
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• 2015

While athletic abilities such as speed, endurance and recovery are important in the horse, genes related to these abilities have not been extensively investigated. Here, we characterized the horse peroxisome proliferator-activated receptor delta ($PPAR{\delta}$) gene and analyzed the expression of $PPAR{\delta}$ during exercise. $PPAR{\delta}$ is a known regulator of ${\beta}$-oxidation, muscle fiber transformation, and running endurance. Through evolutionary analysis using the synonymous and non-synonymous mutation ratio, it was revealed that positive selection occurred in the horse $PPAR{\delta}$ gene. Two important domains related to nuclear hormone receptors, C4 zinc finger and ligand binding domain, were also found to be conserved well in horse $PPAR{\delta}$. Horse $PPAR{\delta}$ was expressed ubiquitously in many tissues, but the expression level was various depending on the tissues. In the skeletal muscle, $PPAR{\delta}$ increased about 2.5 folds after 30 min of exercise. Unlike in muscle, the increase of $PPAR{\delta}$ expression was observed at 60 min but not 30 min of exercise in leukocytes. This finding might be useful for testing the endurance of horse using blood samples. Conclusively, the horse $PPAR{\delta}$ gene is evolutionarily conserved well and can be used as a biomarker of endurance in horse.