• Laser Solutions
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• v.13 no.3
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• pp.19-26
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• 2010

In this study, fundamental experiment was conducted with various strength of UHSS (Ultra High Strength Steel) by $CO_2$ laser. And then, butt and lap joint laser welding with boron alloyed steel and Al-Si coated boron alloy steel have been done by changing laser beam feature, existence of gap and existence of coating layer to know welding characteristics of those materials. As a result, in case of fundamental experiment with various strength steel, hardening was found in the weld metal of all tested materials and softening was found at the heat affected zone of SGAFC 1180. In case of laser butt welding of UHSS, mechanical properties was improved by using small laser beam diameter and Al-Si coating layer caused fracture of weld metal. In case of laser lap welding of UHSS, Al-Si coating layer resulted in formation of intermetallic compound at the fusion boundary where fracture occurred. Al-Si coating layer caused lowering mechanical properties of weld metal.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.72-76
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• 1998

Gardenia yellow pigment produced by Gardenia jasminoides Ellis was tested for reverse mutagenic test in Salmonella typhimurium stains TA1535, TA1537, TA98 and TA100 at concentrations raging form 6.25 to 200$\mu\textrm{g}$/$m\ell$ per plate. No significant reverse mutagenic activity was observed in any of the S. typhimurium strains, in either presence or absence of S9 mix. There was no toxicity to the bacteria. These result indicate that yellow pigment doesn't have mutagenicity.

• BMB Reports
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• v.28 no.2
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• pp.155-161
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• 1995

A nicotinic acetylcholine receptor (nAchR) isolated from the electric tissues of Torpedo californica has been reconstituted into a vesicle comprising a bifunctional azo-ligand (Bae 1) compound, and a liposome containing phospholipids and cholesterol (1 : 1, w/w). The liposome-mediated reconstituted receptor showed a concentration-dependent response to cholinergic drugs in a lithium ion flux assay. This liposome-mediated reconstituted nAchR was immobilized onto an electrode using various synthetic polymers which were tested for their response to the cholinergic ligands. The immobilized nAchR not only exhibited a linear response to a wide range of cholinergic ligand concentrations but also retained an operational stability which lasted for longer than 6 days. Thus, this result provides a basis for application of the immobilized nAchR-based biosensor in detecting cholinergic ligands in vitro.

• The Journal of Information Systems
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• v.19 no.4
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• pp.111-136
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• 2010

This study examined the difference in the usage of internet banking users between Korea and China. This model tests various theoretical research hypotheses relating to internet banking, The Unified Theory of Acceptance and Use of Technology(UTAUT). The factors influencing on the use intention of Internet banking have been classified as performance expectancy, effort expectancy, social influence and facilitating conditions. The proposed model was empirically tested using data collected from a survey of internet banking users in Korea and China. The model is used by SPSS 15.0 and AMOS 7.0 for analysis on the sample collected from 272 respondents. The result of hypothesis testing are as follows. First, performance expectancy and social influence positively influence use intention of internet banking user both Korea and China. Second, facilitating conditions only positively influence on the usage of internet banking users in Korea. On the other side, effort expectancy do not influence the use intention of internet banking users in both two countries. The results of study will provide practical implications on the internet banking in Korea and China.

• The Journal of Information Systems
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• v.19 no.4
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• pp.253-270
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• 2010

The adjustment of negative emotions in later life is related to the quality of life and life satisfaction. any studies have examined how to control the negative emotions in related to physical, psychological, and social relationships. As the digital media and contents positively influence elder's mental and somatic well-being, it is significant to examine this problem from IT usage, especially the selection of digital contents. This study validated the theoretical study through a qualitative exploratory study comprising both negative emotions and the selection of digital contents, and empirically tested the proposed research model on the older people. The result shows the pattern of linkages between the grief of loss and the pursuit of digital contents. Loss from being parted by death and loss of relations was positively related to the information seeking contents. Economical loss and loss of physical functions was positively related to the innovation seeking contents. Loss of physical functions and Loss from being parted by death was positively related to the emotion seeking contents. And economic loss and loss of relations was positively related to the entertainment seeking contents.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.821-827
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• 2010

Gene delivery that provides targeted delivery of therapeutic genes to the cells of a lesion enhances therapeutic efficacy and reduces toxic side effects. This process is especially important in cancer therapy when it is advantageous to avoid unwanted damage to healthy normal cells. Incorporating cancer-specific ligands that recognize receptors overexpressed on cancer cells can increase selective binding and uptake and, as a result, increase targeted transgene expression. In this study, we investigated whether a peptide capable of homing to hepatocellular carcinoma (HCC) could facilitate targeted gene delivery by cationic liposomes. This homing peptide (HBP) exhibited selective binding to a human hepatocarcinoma cell line, HepG2, at a concentration ranging from 5 to 5,000 nM. When conjugated to a cationic liposome, HBP substantially increased cellular internalization of plasmid DNA to increase the transgene expression in HepG2 cells. In addition, there was no significant enhancement in gene transfer detected for other human cell lines tested, including THLE-3, AD293, and MCF-7 cells. Therefore, we demonstrate that HBP provides targeted gene delivery to HCC by cationic liposomes.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.435-441
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• 2009

In the present study, we analyzed the defensin protein deduced from Korean radish (Raphanus sativus L.) seeds.To express the genes in E. coli, we constructed a recombinant expression vector with a defensin gene, named rKRs-AFP gene isolated from Korean radish seeds. Over expressed rKRs-AFP proteins was separated by SDS-PAGE to determine the purity, and protein concentration was determined by the Bradford method. Antifungal activity was assessed by disk assay method against the tested fungi. As a result, when 500 mL of cell culture were disrupted by sonicator, 32.5 mg total proteins were obtained. The purified protein showed a single band on SDS-PAGE with estimated molecular weight about 6 KDa, consistent with the molecular mass calculated from the deduced amino acid sequence. The purified rKRs-AFP protein showed remarkable antifungal activities against several fungi including Aspergillus niger, Botrytis cinerea causing the gray mold disease, and Candida albicans. In field tests using the purified rKRs-AFP protein, the protein showed the reducing activity of disease spot and the mitigating effect of spreading of disease like agrichemicals. The immuno-assay of rKRs-AFP protein showed that the purified protein entirely accumulated at B. cinerea cytoplasm through the hyphal septa shown by fluorescence imaging. There was no fluorescence inside the cell, when the hypha was incubated without the protein. These all results indicate that the recombinant rKRs-AFP proteins can be utilized as a potential antifungal drug to control harmful plant fungal pathogens.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1578-1583
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• 2008

Rhizobacteria are used as inoculants to enhance crop yield and for biological control of fungal pathogens. Fluorescent pseudomonads isolated from the rhizosphere of groundnut showed suppression of the phytopathogen Macrophomina phaseolina that causes charcoal rot of groundnut, an economically important agroproduct. Two strains of fluorescent pseudomonads, designated as PS1 and PS2, were selected as a result of in vitro antifungal activity. After 5 days of incubation at $28{\pm}1^{\circ}C$, both PS1 and PS2 caused clear inhibition zones in dual cultures, restricting the growth of M. phaseolina by 71 % and 74%, respectively. Both the strains were capable of producing siderophores, indole acetic acid, and hydrocyanic acid, and causing phosphate solubilization under normal growth conditions. These strains, when used as inoculants in groundnut, enhanced germination up to 15% and 30% with subsequent increase in grain yield by 66% and 77%, respectively. Conversely, when the pathogen alone was tested 57% decrease in yield was recorded. Thus the studies revealed the potential of the two pseudomonads not only as biocontrol agents against M. phaseolina, but also as a good growth promoter for groundnut.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.8
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• pp.1331-1340
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• 2010

This study examines if the uniforms of dental hygienists influence the formation of professional identity. A self-administered survey was conducted on 534 dental hygienists in Seoul, Gyeonggi, and Incheon from March 28 to April 15, 2007. The dependent variable was professional identity. The independent variables were the organizational characteristics, uniform characteristics, and attitudes towards uniform. For the data analysis, we used t-test and hierarchical regression analysis. Using a t-test, we found the relationship between the color of the uniform and attitudes towards uniforms. The white uniform turned out to be associated with a positive perception of uniform function and uniform-image fit. The result of hierarchical regression analysis shows that the color of the uniform, perception of uniform functioning, and uniform satisfaction were statistically significant in predicting professional identity. We also tested the same model for two groups, those with and without image concern. The test results show that the significant factors were different for these two groups. This study confirms the function of uniforms in constructing professional identity and implies the need to have broader perspectives in studying uniforms.

• Ocean and Polar Research
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• v.28 no.2
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• pp.187-199
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• 2006

The Kuroko-type seafloor massive sulfide deposits found in the western Pacific have been considered to have potentials for economic recovery of Au, Ag, Cu, Zn, and Pb. In this study, a preliminary model was developed for the technical and economic evaluation of them. The FRSC site on Lau Basin in the Tonga EEZ was selected as a target. In this study, no construction In for the metallurgical processing subsystem was accounted for. Instead, it was assumed to sell the Cu, Zn, and Pb concentrates to the existing sulfide customer smelter. The low total investment costs for the development make the venture very attractive. However, the result of the economic feasibility evaluation is still less attractive with the mean metal yield of the Kuroko on land. It is considered that commercial mining may be plausible if the richer metal yields are applied to the development. Quantitative information for metal yield is necessary for a more accurate evaluation. However, the important resource potential information regarding the amount of ore body, the inside structure, and the metal yields have not yet been clarified sufficiently. h addition, the flotation of ore body using seawater has not been tested yet. It is necessary to solve these problems through the experimental R&D and a survey.