• International Commerce and Information Review
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• v.11 no.2
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• pp.233-257
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• 2009

The 21st century is witnessing the explosive increase in the usage of internet and international electronic transactions. Due to the unique characteristics of the electronic information, substantial part of such transaction can and do take the form of cross-border transactions. However, there have not been settled appropriate set of rules applicable to the international electronic transactions. Currently, in respect to e-L/C transactions in international trade, there are laws such as Electronic Transaction Basic Act in our country, E-Trade Promotion Act, E-Signature Law, Act on Promotion of Information and Communication Network Utilization and Information Protection and Marine Charter 5 in the Commercial Law. Nevertheless, a complete legislation, that is a uniform rule for e L/C which could support e L/C transactions fully hasn't been established yet. Accordingly, those laws concerned need to improve to regulate e-L/C transactions. The purpose of this paper is to look into the national status for law readjustment to prepare for a new electronic environment and to use appropriately the e-L/C issued by electronic means, and to conduct a comparative analysis on the related regulations to introduce a pertinent laws and propose related regulations to contribute to the making of effective laws to regulate e-L/C.

• Journal of Microbiology
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• v.43 no.6
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• pp.499-502
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• 2005

Methylophaga sp. strain SK1 is a new restricted facultative methanol-oxidizing bacterium that was isolated from seawater. The aim of this study was to characterize the electron carriers involved in the methanol oxidation process in Methylophaga sp. strain SK1. The gene encoding cytochrome $c_L$ (mxaG) was cloned and the recombinant gene was expressed in Escherichia coli $DH5\alpha$ under strict anaerobic conditions. The recombinant cytochrome $c_L$ had the same molecular weight and absorption spectra as the wild-type cytochrome $c_L$ both in the reduced and oxidized forms. The electron flow rate from methanol dehydrogenase (MDH) to the recombinant cytochrome $c_L$ was similar to that from MDH to the wild-type cytochrome $c_L$. These results suggest that recombinant cytochrome $c_L$ acts as a physiological primary electron acceptor for MDH.

• Communications of the Korean Mathematical Society
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• v.32 no.3
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• pp.709-714
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• 2017

For every interval [a, b], we denote by (${\bar{x}}_A,{\bar{y}}_A$) and (${\bar{x}}_L,{\bar{y}}_L$) the geometric centroid of the area under a catenary y = k cosh((x - c)/k) defined on this interval and the centroid of the curve itself, respectively. Then, it is well-known that ${\bar{x}}_L={\bar{x}}_A$ and ${\bar{y}}_L=2{\bar{y}}_A$. In this paper, we show that one of ${\bar{x}}_L={\bar{x}}_A$ and ${\bar{y}}_L=2{\bar{y}}_A$ characterizes the family of catenaries among nonconstant $C^2$ functions. Furthermore, we show that among nonconstant and nonlinear $C^2$ functions, ${\bar{y}}_L/{\bar{x}}_L=2{\bar{y}}_A/{\bar{x}}_A$ is also a characteristic property of catenaries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.465-469
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• 1993

This study was designed to investigate fatty acid composition of salt-fermented seafoods in Chonnam area. The seven samples were analyzed for fatty acid composition. The contents of lipid was highest in salt-fer-mented anchovies and followed by salt-fermented small mullets, salt-fermented oysters, salt-fermented sea-arrows and salt-fermented small shrimps. The ratio of fatty acid composition depended on the samples but the major fatty acids were $C_{l6:0}$, $C_{20:5}$, $C_{l6:1}$, $C_{22:6}$, and $C_{l8:1}$ among all samples. The composition of n-3 polyunsaturated fatty acids was highest in salt-fermented sea-arrows (39.11%) and followed by salt-fermented small shrimps, salt-fermented oysters, salt-fermented anchovies and salt-fermented small mullets. In n-3 polyunsaturated fatty acids, $C_{20:5}$ was relatively abundant in salt-fermented oysters (17.71%) and salt-fermented sea-arrows (16.38%), and $C_{22:6}$ in salt-fermented sea-arrows (22.22%) and salt-fermented small shrimps (15.13~21.50%). However, $C_{22:6}$ was very little in salt-fermented small mullets.l mullets.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.381-391
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• 1993

To evaluate the antioxidizing effect of flavonoid on fish oil and peroxidized fish oil, rats were fed with diets containing 5% corn oil (CO), 5% corn oil and 15% fresh fish oil (FO) or peroxidixed fish oil (PFO) for 4weeks. An half of FO and PFO group rats were injected with 10mg flavonoid (+)-catechin (a day per kg body weight) (FO-C and PFO-C). FO and FO-C group rats showed higher increase in body weight as compared to PFO, PFO-C group rats. Whereas, the opposite result was obtained in case of liver weight increase. In addition, catechin apparently reduced liver weight by 12~17%. Phospholipid, cholesterol, triglyceride and lipid peroxide content in serum and cholesterol, lipid peroxide content in liver and adipose tissue of PFO, PFO-C group rats were significantly higher than those of FO, FO-C one. These results suggested that catechin reduced the synthesis of lipid and protected effectively against lipid peroxidation. In fatty acids profile of neutral lipid and phospholipid, the ratio of polyunsaturated fatty acids (PUFA) versus saturated fatty acids (SFA) in PFO, PFO-C were lower than that of FO or FO-C because of ruduced PUFA. Contrary to our expectation, the enzyme activities of superoxide dismutase(SOD), catalase and glutathione peroxidase (GSH-Px) in rat liver of FO and FO-C group were lower than those of PFO and PFO-C group. These results were quite interesting and might be explained in terms of homeostasis. In case of total lipid in liver, $C_{20:5}$, $C_{22:6}$ fatty acids were decreased in rat fed peroxidized fish oil. In conclusion, catechin was considered to be an antioxidative and hepatoprotective drug and hypolipidemic agent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5644-5651
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• 2014

Propolis is an extremely safe natural antimicrobial substance that has been reported to have powerful antibacterial efficacy. The aim of this study was to evaluate the inhibitory effects of propolis against Candida albicans (C. albicans). Propolis was collected from the honey bee Apis mellifera. The strain of C. albicans was cultivated overnight in liquid media incubated at $37^{\circ}C$. The antimicrobial activity was investigated using phosphate buffered saline (PBS), 3% sodium hypochlorite (NaOCl), 0.1% chorhexidine (CHX), and propolis extracts ($5{\mu}l/ml$, $10{\mu}l/ml$). C. albicans were sensitive to 3% NaOCl, 0.1% CHX, and propolis ($5{\mu}l/ml$, $10{\mu}l/ml$) with zones of inhibition of 15, 14.5, 16, and 17 mm, respectively. The CFU of PBS, 3% NaOCl, 0.1% CHX, $5{\mu}l/ml$ and $10{\mu}l/ml$ of propolis led a 1, 7, 7, 5 and 7-log reduction. Among the groups tested, C. albicans was most sensitive to $10{\mu}l/ml$ of propolis, which showed the largest inhibition zones. Therefore, propolis can be a new antimicrobial therapy for oral mucosa disease in traditional medicine.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.51-60
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• 2020

Background: Programmed death-ligand 1 (PD-L1) expression is tested by immunohistochemistry (IHC)-22C3, SP263, and SP142. The aim of this study is to evaluate the correlation among the three methods of PD-L1 IHC in non-small cell lung cancer (NSCLC) and clinical significance of PD-L1 expression in lung adenocarcinoma with an epidermal growth factor receptor (EGFR)-tyrosine kinase domain mutation. Methods: The results of 230 patients who were pathologically confirmed as having NSCLC; tested using PD-L1 IHC 22C3, SP263, and SP142 methods; and evaluated via the peptide nucleic acid clamping method to confirm EGFR mutation, were analyzed in this study. Results: 164 patients underwent both the SP263 and 22C3 tests. There was a significant positive correlation between the outcomes of the two tests (Spearman correlation coefficient=0.912, p<0.001), with a derived regression equation as follows: 22C3=15.2+0.884×SP263 (R²=0.792, p<0.001). There was no relationship between the expression of PD-L1 and clinical parameters, including EGFR-tyrosine kinase inhibitor (TKI) mutation. The PD-L1 expression in patients treated with EGFR-TKI yielded a 2-month-shorter progression period than that in the PD-L1-negative group. However, this did not reach statistical significance (PD-L1<1% vs. PD-L1≥1%, 10 months vs. 8 months). Conclusion: The results of the 22C3 and those of SP263 methods were in good correlation with one another. Since the PD-L1 expression is not influenced by the EGFR mutation, it is necessary to perform a PD-L1 test to set the treatment direction in the patients with EGFR-mutant NSCLC.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.717-722
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• 2004

Response surface methodology was used to optimize production conditions of monoacylglycerol (MAG) and diacylglycerols (DAG) from corn oil by enzymic glycerolysis. Contents of $1,3-DAG\;(Y_1),\;1,2-DAG\;(Y_2),\;total\;DAG\;(Y_3),\;MAG\;(Y_4)$, and total $DAG+MAG\;(Y_5)$ were obtained. Conditions were optimized using central composite design with incubation temperature $(35-75^{\circ}C,\;X_1)$, incubation time (1-11 hr, $X_2$), and amount of hexane added (0-2 mL, $X_3$) as three variables. Content of 1,3-DAG was maximized by 20.43 area% at incubation temperature of $44.92^{\circ}C$, incubation time of 10.24 hr, and hexane content of 1.16 mL, whereas that of 1,2-DAG (26.78 area%) was maximized at $56.32^{\circ}C$, 6.95 hr, and 1.04 mL, respectively. Predicted maximum total DAG content was 45.09 area% at $53.82^{\circ}C$, 8.03 hr, and 1.08 mL, while production conditions of MAG (9.57 arae%) were $64.14^{\circ}C$, 7.00 hr, and 0.13 mL. At variables of $54.07^{\circ}C$, 7.98 hr, and 1.02 mL, maximum content of total DAG+MAG predicted by RSM was 53.54 area%.

• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.612-617
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• 1993

Some vanadium(III) complexes have been prepared from the reaction of VC$l_3$ with N, P, O-donating ligands and characterized by elemental analysis, $^1$H-NMR infrared and UV-Visible spectroscopy. 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane and 1,1'-bis(diphenylphosphino)ferrocene were chosen as coordinating ligands. Stretching frequency ${\nu}g$(V-Cl) of complexes appears) at 298∼367 cm-1, which show octahedral geometries. Stretching frequency of ${\nu}g$(V-X) (X = N, P, O) indicates that ligands are coordinated to vanadium(III). Stretching frequency ${\nu}g(C{\equiv}N)$ of acetonitrile in these complexes are characteristically shifted to about 70 c$m^{-1}$ higher compared with that of a free ligand (2260 c$m^{-1}$). Bending frequency of $\delta(C{\equiv}N)$ is also shifted to about 60 c$m^{-1}$ higher compared with that of a free ligand (377 c$m^{-1}$). Finally each vanadium(III) complex showed the following formulation; [VC$l_3$(L)$_2$MeCN] or [VC$l_3$(L-L)MeCN].

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.1044-1055
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• 1994

The preparation of ZrC/SiC mixed powders from $ZrSiO_4/C$ and $ZrSiO_4/Al/C$ systems was attempted in the temperature range below $1600^{\circ}C$ under Ar or $Ar/H_2$ gas flow(100-500ml/min). The formation mechanism and kinetics of ZrC/SiC were suggested and the resultant powders were characterized. In $ZrSiO_4/C$ system, ZrC and SiC were formed by competitive reaction of $ZrO_2(s)$ and SiO(g) with carbon at temperature higher than $1400^{\circ}C$. The apparent activation energy for the formation of ZrC was approximately 18.5kcal/mol($1400-1600^{\circ}C$). In $ZrSiO_4/Al/C$ system, ZrC was formed by reaction of ZrO(g) with Al(l, g) and carbon at temperature higher than $1200^{\circ}C$, and SiC was formed by reduction-carbonization of SiO(g) with Al(l, g) and carbon at temperature higher than $1300^{\circ}C$. The products obtained at $1600^{\circ}C$ for 5h consisted of ZrC with lattice constant of $4.679{\AA}$ and crystallite size of $640{\AA}$, and SiC with lattice constant of $4.135{\AA}$ and crystallize size of $500{\AA}$. And also, the mean particle size was about $21.8{\mu}m$.