• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.652-656
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• 2013

The geographical origin of red ginseng extract (RGE) was studied using a mass spectrometry based electronic nose. Imported RGE and domestic RGE were diluted to 12oBx. The treated RGE was analyzed, and discriminant function analysis (DFA) was used for discriminating of geographical origins. The DFA plots indicated a significant separation of imported RGE and domestic RGE. The F-value of discriminant function first score (DF1) was much higher than that of discriminant function second score (DF2), indicating that discrimination was mainly affected by DF1. Based on DF1, the concentration of domestic RGE to imported RGE shifted to the left side of DFA plot, and the mixing ratio highly correlated to DF1 value. Unknown sample (#2) was closely located to the sample of mixed imported : domestic (6:4) RGE. In the bar graph, the DF1 value correlated to the mixing ratio. Unknown samples (#2) were thought to be mixed with the imported RGE. This technique could be used to efficiently differentiate the geographical origin of RGE.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.192-197
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• 2007

Suppression subtractive hybridization (SSH) was performed to construct an cDNA library of olive flounder Paralichthys olivaceus peripheral blood leukocytes (PBL) stimulated with lipopolysaccharide (LPS). Total 470 clones were randomly selected and sequenced, 214 out of 470 sequences showed identities with known genes and 252 sequences were unknown genes. Among the 218 known genes, 34 sequences were found to be homologous to IL-1RII gene, and 14 sequences were identified as IL-$1{\beta}$. RT-PCR analysis showed that IL-$1{\beta}$ mRNA was induced 1h after LPS-stimulation, and IL-1RII was increased from 3h after stimulation, indicating that most of SSH clones are associated with inflammatory responses in fish, and this SSH cDNA library would be useful to identify bio-defense and immuno-related genes in fish.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.300-307
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• 2015

For selecting Bacillus strains producing high-quality Cheonggukjang, 8 strains were isolated from the different Cheonggukjang samples. Seven of them exhibited the highest 16S rRNA gene sequence similarity value of over 99.9% to Bacillus subtilis subsp. subtilis and one of them showed the similarity to B. licheniformis. All the strains showed positive activities for amylase, cellulase, protease and lipase, and 6 strains are positive for fibrinolytic activity. To confirm the safety of the strains isolated from the samples of Cheonggukjang which are manufactured by traditional method, strains were analyzed for the presence of seven toxin genes of Bacillus cereus and results were found negative. And 7 strains did not produce at all or merely produce both histamine and tyramine, the representative biogenic amines. Biogenic amine degradation analysis by HPLC revealed that, most of them exhibited tyramine degradation activity. For Cheonggukjang fermented by artificial inoculation of selected strains, fermentation property, sensory test, volatile basic nitrogen production and metabolic profiles by $^1H-NMR$ were tested. Seven strains were confirmed to make high-quality Cheonggukjang.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.399-408
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• 2014

Glutathione S-transferases (GSTs) are a superfamily of detoxification enzymes that primarily catalyze the nucleophilic addition of reduced glutathione to both endogenous and exogenous electrophiles. In this study, we isolated and characterized a full-length of alpha class GST cDNA from the abalone (Haliotis discus hannai). The abalone GST cDNA encodes a 223-amino acid polypeptide with a calculated molecular mass of 25.8 kDa and isoelectric point of 5.69. Multiple alignments and phylogenetic analysis with the deduced abalone GST protein revealed that it belongs to the alpha class GSTs and showed strong homology with disk abalone (Haliotis discus discus) putative alpha class GST. Abalone GST mRNA was ubiquitously detected in all tested tissues. GST mRNA expression was comparatively high in the mantle, gill, liver, and digestive duct, however, lowest in the hemocytes. Expression level of abalone GST mRNA in the mantle, gill, liver, and digestive duct was 182.7-fold, 114.8-fold, 4675.8-fold, 406.1-fold higher than in the hemocytes, respectively. Expression level of abalone GST mRNA in the liver was peaked at 6 h post-infection with Vibrio parahemolyticus and decreased at 12 h post-infection. While the expression level of abalone GST mRNA in the hemocytes was drastically increased at 3 h post-infection with Vibrio parahemolyticus. These results suggest that abalone GST is conserved through evolution and may play roles similar to its mammalian counterparts.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.227-235
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• 2015

The objective of this study was to improve the quality of Korean rice wine with wild type yeast strains isolated from various traditional Korean fermented foods. Herein the fermentation and sensory characterization of wild yeast, for the purposes of brewing Korean rice wine, was investigated. 12 yeast strains were examined for their ethanol and glucose tolerance. In addition, the pH, soluble solids, acidity, amino acidity, ethanol content, organic acids, and volatile compounds were also studied for the alcoholic beverages made with the wild yeasts. Almost all Saccharomyces genera yeasts were showed to have a tolerance at 10% ethanol, but non-Saccharomyces genera yeasts displayed a low tolerance. The alcoholic beverages fermented by non-Saccharomyces yeasts demonstrated higher levels of soluble solids, titratable acidity, amino acids, and lower ethanol content, when compared with the alcoholic beverages fermented by Saccharomyces genera yeasts. The organic acid content, such as malic acid, acetic acid, and succinic acid, was seen to also be higher. The electronic nose was analyzed, and discriminant function analysis (DFA) was used for discriminating wild yeast strains. The DFA plots indicated a significant separation of Saccharomyces genera and non-Saccharomyces yeast strains. For volatile compounds, ethyl acetate from non-Saccharomyces yeasts, and ethanol from Saccharomyces genera yeast, a high area ratio was observed.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.637-645
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• 2011

It is well known that high strength concrete with compressive strength higher than 50 MPa shows severe material and structural damages under fire due to spalling. To understand degradation of structural capacity of fire damaged high strength concrete structures, not only thermo-mechanical behavior needs to be defined, but also structural behavior of high strength concrete member under high temperature needs to be investigated. In this study, structural tests are performed by applying axial loads on high strength concrete columns exposed at elevated temperatures for assigned amount of time. The tested columns are prepared to have different concrete strength and polypropylene fiber percentage. The test results show that structural capacity of the columns decreased with increased compressive strength of concrete under same heating condition. Especially, it is interesting to note that high strength concrete columns with polypropylene fiber for spalling proof did not improve structural capacity compared to the columns without polypropylene fiber. The findings from the test are able to improve fire proof design of high strength concrete structural members and predicting structural performance of fire damaged structural members.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.81-89
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• 2011

The previous land gravity data in Korea showed locally biased irregular distribution. Especially, this problem was more serious in the mountainous area where the data density was significantly low. The same problem appeared in GPS/Levelling data thus the precision of the geoid could not be improved. From 2008, new gravity and GPS/Levelling data has been collected by the unified control point and survey on the benchmark project which were funded by the national geographic information institute. The newly obtained data has much better distribution and precision so that it could be used for update precision of geoid model. In this study, the new precision geoid has been calculated based old and new gravity data and this model showed 5.29cm of precision compared to 927 points of GPS/Levelling data. And the degree of fit and precision of hybrid geoid has been calculated 2.99cm and 3.67cm. The new gravimetric geoid has been updated about 27% over whole country. And it showed 42% of precision update due to collection of new gravity data on the Kangwon/Kyeongsang area which showed quite low distribution. In 2010, about 4,000 points of gravity and 300 points of GPS/Levelling data has been obtained by unified control and survey on benchmark project. We expect that new data will contribute to updating geoid precision and veri tying precision more objectively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.171-180
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• 2011

Purpose: The aim of this study was to assess changes in neuropeptide Y (NPY) immunoreactivity in the hypothalamus and interstitial cells of Cajal (ICC) in the small intestine of rats fed high-fat diets (HFD). Methods: Male Sprague-Dawley rats (200~250 g body weight) were randomly divided into two groups, which were the control group (normal chow diet for 6 weeks), and the HFD group (rodent diet with 60% kcal fat for 6 weeks). The immunoreactivity of NPY in the hypothalamus and ICC in the small intestine was evaluated after every feed for 6 weeks. Results: NPY immunoreactivity was observed strongly in the hypothalamic nuclei in the HFD group compared to the control group. The numbers of NPY-immunoreactive (IR) cells were significantly higher in the paraventricular hypothalamic nucleus in the HFD group than in the control group. In the region of Auerbach's plexus (AP) of small intestine, the staining intensity of the ICC-IR cells was reduced in the HFD group compared to the control group. The numbers of ICC in the small intestine with HFD, including ICC in the inner circular and outer longitudinal muscle were significantly lower than in the control group. Conclusion: This study suggested that increasing NPY-IR cells in the hypothalamus may reflect resistance of NPY action after a HFD, and decreasing ICC-IR cells in the small intestine after a HFD is functionally significant in gastrointestinal motility.

• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.31-35
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• 2005

To obtain regeneration system of onion, we analyzed the effects of 2,4-D and BA concentration on the embryogenic callus induction from mature embryos. The highest embryogenic callus induction ratio was shown on MS medium (Murashie and Skoog 1962) containing $2.5\;\cal{mg/L}\;or\;5\;\cal{mg/L}$ picloram after mature embryos were placed on medium. When induced callus were cultured on half strength of MS medium containing $1\;\cal{mg/L}$ Kinetin, the highest shoot formation ratio was observed on MS medium containing $1\;{mg/L}$ 2,4-D and $1\;{mg/L}$ BA. Embryogenic callus were cultured in MS liquid medium containing $1\;\ccal{mg/L}$ of 2,4-D and $1\;\cal{mg/L}$ BA. The suspension cultured cell clumps could be mass propagated. Embryogenic callus were friable, but non-embryogenic callus included a lot of moisture, hence the identification between embryogenic and non-embryogenic callus as easily achieved. When embryogenic callus as cultured on half strength of MS medium containing $1\;\cal{mg/L}$ Kinetin, shoots were induced. The whole plantlet was obtained on rooting medium containing $0.5\;\cal{mg/}$ of NAA.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.230-239
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• 2020

The purpose of this study was to examine how a leader's organizational citizenship behavior (OCB) affects subordinates' interpersonal citizenship behavior (ICB) and job stress levels. A leader's OCB involves taking-charge behavior, loyal boosterism, and the industry. We hypothesized that leader-member exchange (LMX) would mediate the relationship between leader's OCB and subordinates' ICB and job stress level. We tested the model using a sample of 293 employees from different organizations from September 2019 until November 2019. We conducted confirmatory factor analyses of the variables and analyzed the data by using structural equation modeling. We also conducted a CFA to assess the fit of a three-factor model for the leader's OCB items. Empirical findings show that LMX fully mediated the effect of leader's OCB on employees' ICB and job stress level. Leader's OCB had a positive effect on LMX. Moreover, LMX had a positive effect on employees' ICB but had a negative effect on job stress. We found support for our hypotheses that leader's OCB is positively related to ICB but negatively related to job stress, and this relationship is mediated by LMX. We discuss limitations, implications for practice, and future research.