• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.245-256
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• 2008

The current legislation in South Korea clearly states that the tolerance threshold on the adventitious presence of GMO in environment-friendly agricultural products is 3.0% and no GM seed should be detected in their planting seed batches. To date, in Korea, there is no approved GM crop for commercial cultivation in field. However, several GM crops including rice, Chinese cabbage, potato and wild turf grass are currently under risk assessment for their environmental release. Also Korean government (Rural Development Administration, RDA) announced that 11 institutes including universities have been currently certified to carry out a risk assessment of GM crops. Meanwhile, the cultivated area and certified quantities of environment-friendly crops (organic, pesticide-free and low-pesticide) are sharply increasing every year according to the report of National Agricultural Products Quality Management Service (NAQS). In detail, in 2007, the certified quantities of environment-friendly agricultural products were elevated up to 100-fold for organic, 171-fold for pesticide-free and 2,324-fold for low-pesticide crops when compared with those in 1999. The total certified quantity of environment-friendly cereal crops in 2007 was equivalent to 6.4% of total production of cereal crops. Moreover, 24% of total production of root and tuber crops such as potato and sweet potato were certified for environment-friendly agricultural products. In these circumstances, I strongly suggest that current legislations on GM crop's safety management should be revised to include strategies for the coexistence of GM with non-GM crops, especially environment-friendly crops before GM crop is approved to be cultivated for commercialization. Since all types of crops are grown in an open environment, the adventitious presence of GM crops among non-GM crops is inevitable if appropriate measures for coexistence are not established for species by species such as isolation distance, workable management measures to minimize admixture.

• Journal of Nutrition and Health
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• v.41 no.7
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• pp.602-611
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• 2008

We compared antiobese, hypocholesterolemic, antiplatelet and antioxidant effect of 10% green tea powder and 3% green tea extract in rats pair fed 5% cholesterol diets. The final body weight was decreased significantly compared with the control (p < 0.05). Plasma and liver total cholesterol were lower in group of green tea powder or extract, but not statistically different. HDL cholesterol was increased significantly in group of green tea powder compared with the control or green tea extract (p < 0.05). Plasma triglyceride was significantly decreased in group of green tea extract compared with green tea powder, and green tea powder compared with the control respectively (p < 0.05). Liver triglyceride was significantly decreased in group of green tea powder or green tea extract compared with the control (p < 0.01). Platelet aggregations in the maximum and initial slope were not different among groups. Hemolysis was significantly lower in group of green tea powder compared with the control (p < 0.05). Plasma TBARS production was decreased in group of green tea extract compared with the control (p < 0.05). Na passive leak in intact cells was not different, but Na leak in AAPH treated cell was significantly decreased in group of green tea powder than the control (p < 0.05). The leak increase (${\Delta}Na$ Leak) after AAPH treatment was significantly decreased in groups of green tea powder and extract compared with the control (p < 0.05). Isotope excretion after $^{14}C$-cholesterol ingestion was significantly increased in group of green tea extract compared with the control or the green tea powder (p < 0.05). Consumption of green tea in powder or extract may give beneficial effects in weight control and plasma lipid profiles, impeding metabolic syndrome. More studies are needed to clarify what component of green tea and what mechanism are involved in antiobese and hypolipedemic actions of green tea.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.315-322
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• 2006

FS11052, a novel microbial metabolite from Streptomyces spp. was identified as a small molecular substance and shown inhibition activities for the release of neurotransmitter from rat hippocampal neuron and PC12 cells. FS11052 is an inhibitor of tritiated norepinephrine ($[^3H]-NE$) release in high $K^+$ buffer solution containing ionomycin, indicating that FS11052 inhibits neurotransmitter release after the influx of $Ca^{2+}$ ions. When examined the effect of FS11052 on glucuronidase release from guinea pig neutrophils, FS11052 inhibited glucuronidase release: when treated with $5{\mu}g/ml$ of FS11052, which was not induced cellular cytotoxicity. The fact that the glucuronidase release in neutrophil and norepinephrine release in neuron was inhibited suggests the similarity in the locations and the mechanisms of FS11052 action targets. When treated with $5{\mu}g/ml$ of FS11052, $[^3H]-NE$ release and neurite extension for both rat hippocampal neurons and PC12 cells were prevented. These observations of FS11052 functioning as an inhibitor of neurotransmitter release suggest that FS11052 has an important role in synaptic transmission in neuron.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.3
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• pp.61-74
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• 2015

This study attempts to empirically examine the influence of entrepreneurial education in university on entrepreneurial intentions of undergraduate and graduate students as potential entrepreneur and new moderating factors on the relationship between entrepreneurial education and entrepreneurial intentions. We suggested EO(innovativeness, risk-taking propensity, proactiveness and locus of control) and environmental factors(entrepreneurial family background and resource accessibility) as new moderating factors in the relationship. For this study, the following research questions are raised : First, is there a significant difference in entrepreneurial intentions of enrolled and unenrolled students in entrepreneurial education? Second, does entrepreneurial education affect entrepreneurial intentions positively? Finally, do EO and environmental factors have moderating effects in the relationship between entrepreneurial education and entrepreneurial intentions? In order to test our research model, the current study collected data from 265 undergraduate and graduate students who are majoring in natural sciences or engineering in Seoul National Univ., Hanyang Univ., and KAIST. To investigate our research questions and hypotheses, independent-sample T-test and hierarchical regression analysis were employed. The results of empirical analysis revealed that entrepreneurial education positively related to entrepreneurial intentions and that the relationship between entrepreneurial education and entrepreneurial intentions moderated by EO and environmental factors. First, the result showed the significant difference in entrepreneurial intentions between enrolled and unenrolled students in entrepreneurial education. Entrepreneurial intentions of students who enrolled entrepreneurial education was higher than others. Second, entrepreneurial education affected the entrepreneurial intentions positively. Finally, the moderating effects of innovativeness, risk-taking propensity, proactiveness and entrepreneurial family background among investigated six moderators were significant. entrepreneurial education-entrepreneurial intentions relationship was even stronger under high innovativeness and high proactiveness. But risk-taking propensity and entrepreneurial family background decreased the effect of entrepreneurial education on entrepreneurial intentions.

• Development and Reproduction
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• v.15 no.4
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• pp.365-371
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• 2011

Water temperature governs various biological events in many aquatic animals including fish. Temperature changes the rates of gametogenesis and development, in some cases, is even capable of reversing fish sex. Treatments of fish with unusually high temperature are known to induce the expression of HSP70 gene. Development of an effective inhibitor for HSP70 gene expression is, thus, crucial to study the role of HSP70 in the temperature sensitive biological events. We have investigated the inhibitory effect of quercetin, 3,3',4',5,7-pentahydroxyflavon, a natural flavonid, on the expressions of HSP70 gene induced by high temperature ($36^{\circ}C$) in the Nile tilapia, Oreochromis niloticus, larvae and juveniles (10~13 cm in total length). The expression of HSP 70 gene was significantly decreased in tilapia larvae immersed in 50 ${\mu}M$ or 100 ${\mu}M$ quercetin solution for 6 hours before the exposure to high temperature (P<0.05). In particular, the level of HSP70 expression in fish treated with 100 ${\mu}M$ was as low as that of fish without high temperature treatment. Juveniles of tilapia were individually injected with 0.1 $m{\ell}$ of either 0.5 mM, 5 mM or 20 mM of quercetin solution before the exposure to high temperature. As the results, the expression of HSP70 gene in the gonad and brain of juvenile fish was significantly inhibited by the injection of 0.5 mM quercetin solution (P<0.05), but not by higher concentrations. We report, for the first time in the fish, that quercetin effectively inhibits the expression of HSP70 gene induced by high temperature and 100 ${\mu}M$ for the immersion of larvae and 0.5 mM for the injection to juvenile can be used for the effective concentrations for the study of temperature sensitive biological events in tilapia.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.619-629
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• 2020

The National Groundwater Monitoring Network (NGMN) in South Korea has been implemented in alluvial/ bedrock aquifers for efficient management of groundwater resources. In this study, aquifer types were reclassified with unconfined and confined aquifers based on water-level fluctuation and water quality characteristics. Principal component analysis (PCA) of water-level data from paired monitoring wells of alluvial/bedrock aquifers results in the principal components of both aquifers showing similar water-level fluctuation pattern. There was no significant difference in the rate of water-level rises responding to precipitations and in the NO₃-N concentrations between the alluvial and bedrock aquifers. In contrast, in the results classified with the hydrogeological type, the principal components of water level were different between unconfined and confined conditions. The water-level rises to precipitation events were estimated to be 4.6 (R²=0.8) in the unconfined and 2.1 (R²=0.4) in the confined aquifers, respectively, indicating less impact of precipitation recharge to the confined aquifer. The confined aquifers have the average NO₃-N concentration below 3 mg/L, implying the natural background level protected from the sources at surface. In summary, reclassification of aquifers into hydrogeological types clearly shows the differences between unconfined and confined aquifers in the water-level fluctuation pattern and NO₃-N concentrations. The hydrogeologic condition of aquifer could improve groundwater resource management by providing critical information on groundwater quantity through recharge estimation and quality for protection from potential contamination sources.

• Journal of Life Science
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• v.18 no.10
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• pp.1447-1454
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• 2008

Effect of heat processing on thermal stability of kudzu root isoflavone was investigated for future use such as various processed foods and functional foods. Kudzu root extracts were heated at 80, 100, 121, 140, 165, and $180^{\circ}C$ for up to 90 minutes before and after concentration, respectively. Changes in the amount of isoflavones were monitored using HPLC and thermal stability was investigated using Arrhenius equation. The amount of both daidzin and genistin decreased slightly during heating at 80, 100 and $121^{\circ}C$ but decreased significantly above $140^{\circ}C$. This indicated that daidzin and genistin are stable at temperatures near the boiling point of water. The degradation of both daidzin and genistin occurred in two steps and each step showed typical first order kinetic. The degradation rates were faster in the first step than the second step in both daidzin and genistin. Additionally, the degradation was accelerated when they heated after concentration compared to the sample heated before concentration. These results suggested that degradation of kudzu root isoflavone was highly dependent on both their concentration and heating temperature. This study provides the basic information on thermal stability of kudzu root isoflavones, which can be used for future processing of functional foods.

• Journal of Life Science
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• v.24 no.10
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• pp.1092-1101
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• 2014

In this study, the distribution patterns of Quercus mongolica and Q. serrata in Korea were investigated, and the possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Seorak was inferred by flavonoid analyses. The most critical factor in the vertical and horizontal distribution patterns of Q. mongolica and Q. serrata was the temperature, in accordance with latitude and altitude. The species showed a zonal distribution, with a Q. mongolica zone in the upper area and a Q. serrata zone in the lower area. In Mt. Seorak, Central Korea, the range of the vertical distribution of Q. mongolica was generally above an altitude of 100 m, whereas that of Q. serrata was an altitude of 0-400 m (-500) and rarely above an altitude of 500 m. However, in Mt. Jiri, Southern Korea, Q. serrata was found up to an altitude of 1,000~1,200 m, whereas the frequency of Q. mongolica was reduced at lower elevations and the species was rare below an altitude of 300 m, although pure stands were found on higher mountain slopes above an altitude of 1,200 m. The altitudinal distribution of the two species overlapped, where the two species occurred together. The leaf flavonoid constituents of thirty-four individuals of Q. mongolica and Q. serrata in Mt. Seorak and Mt. Jiri, Korea were examined. Twenty-four flavonoid compounds were isolated and identified. These were glycosylated derivatives of flavonols kaempferol, quercetin, isorhamnetin, myricetin. Five compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside, a high concentration of three acylated compounds (kaempferol 3-O-glucoside, quercetin 3-O-glucoside, and quercetin 3-O-galactoside), and a relatively low concentration or lack of rhamnosyl flavonol compounds. Intraspecific variations, however, were found in the flavonoid profiles of Q. mongolica and Q. serrata, and the flavonoid profiles of individuals belonging to the two species in a hybrid zone (sympatric zone) tended to be similar, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through introgressive hybridization between Q. mongolica and Q. serrata in Mt. Seorak.

• Journal of Life Science
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• v.26 no.11
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• pp.1237-1244
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• 2016

A comprehensive analysis of the genetic diversity and relationship of the cold-water fishery walleye pollock (Theragra chalcogramma), the most abundant economically important fishery resource in the East sea of Korea, has not been carried out, despite its importance in Korea. The present study assessed the genetic diversity and relationship between five walleye pollock populations (Korean population, Russian population, USA population, and Japanese populations) of T. chalcogramma using eight microsatellite DNA (msDNA) markers to provide the scientific data for the preservation and management of the Pollock fishery resource. The results of the analysis of 186 individuals of the Pollock revealed a range of 7.13-10.63 numbers of alleles (mean number of alleles=9.05). The means of observed heterozygosity ($H_O$), expected heterozygosity ($H_E$) were 0.732 and 0.698, respectively. The results of genetic distance, Pairwise $F_{ST}$, UPGMA (UPGMA: un-weighted pair-group method with an arithmetical average) (the phylogenetic tree), PCA (PCA: Principal Coordinate analysis) analysis pointed to significant differences between the Korean population, Russian population, USA population, and Japanese populations, although small (p<0.05). These results shed light on the genetic diversity and relationships of T. chalcogramma and can be utilized for research on the evaluation and conservation of Korean T. chalcogramma as genetic resources.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.1
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• pp.1-7
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• 2017

Zerumbone is a major component of the essential oil from Zingiber zerumbet Smith, which is a kind of wild ginger. In addition, various biological functions, such as liver protection, pain relief, atherosclerosis, and antimicrobial activity have been reported. It is also known to be effective in the proliferation of immune cells and the expression of cytokines. In this study, we investigated the effects of zerumbone on monocyte activation. First, it was confirmed that the proliferation of THP-1 cells was increased by zerumbone. The strongest increase in THP-1 proliferation after lipopolysaccharide treatment was observed at $5{\mu}M$ zerumbone treatment, and the increase of cell proliferation without lipopolysaccharide was the highest at $10{\mu}M$. Conversely, when treated with $50{\mu}M$ zerumbone, a rapid decrease of proliferation was observed regardless of the presence of lipopolysaccharide (LPS). The phosphorylation of signaling protein, Erk, induced by LPS was also increased by zerumbone. The strongest increase in phosphorylation was observed when treated with $50{\mu}M$ of zerumbone with reduced proliferation. The activity of transcription factor $NF-{\kappa}B$ was not significantly altered by zerumbone alone, but increased when treated with lipopolysaccharide. Furthermore, the transcription of the inflammatory cytokines $TNF-{\alpha}$ and IL-8, which are regulated by $NF-{\kappa}B$, is also increased by zerumbone. These results suggest that zerumbone can enhance the proliferation and activity of monocytes. Furthermore, it is believed that zerumbone can enhance rthe immune responses through increased monocyte activity in bacterial infections with LPS, thereby helping to treat effective bacteria.