• Proceedings of the Botanical Society of Korea Conference
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• 1996.07a
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• pp.61-74
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• 1996

Human and monogastric animals can not synthesize 10 out of the 20 amino asids and therefor need to obtain these from their diet. The plant seed is a major source of dietary protein. It is particular important in their study to increase nutritional quality of the seed storage proteins. The low contents of lysine, asparagine and threonenein various cereal seeds and of cystein and methionine. In legume seeds is due to the low proportions of these amino acids in the major storage proteins, we have tried to apply the three strategies; (1) mutagenesis and selection of specific amino acid analogue resistance, (2) cloning and expression study of lysine biosynthesis related gene, (3) transfomation of lysine rich soybean glycinin gene. The 5-methyltryptophan (5MT) resistant cell lines, SAR1, SAR2 and SAR3 were selected from anther derived callus of rice (Oryza sativa L. "Sasanishiki"). Among these selected cell lines, two (SAR1 and SAR3) were able to grow stably at 200 mg/L of 5MT. Analysis of the freed amino acids in callus shows that 5MT resistant cells (SAR3) accumulated free tryptophan at least up to 50 times higher than those that of the higher than of SAS. These results indicated that the 5MT resistant cell lines are useful in studies of amino acid biosynthesis. Tr75, a rice (Oryza sativa L., var. Sasanishiki) mutant resistant to 5MT was segregated from the progenies of its initial mutant line, TR1. The 5MT resistant of TR75 was inherited in the M8 generations as a single dominant nuclear gene. The content of free amino acids in the TR75 homozygous seeds increased approximately 1.5 to 2.0 fold compared to wild-type seeds. Especially, the contents of tryptophan, phenylalanine and aspartic acid were 5.0, 5.3 and 2.7 times higher than those of wild-type seeds, respectively. The content of lysine is significantly low in rice. The lysine is synthesized by a complex pathway that is predominantly regulated by feedback inhibition of several enzymes including asparginase, aspatate kinase, dihydrodipicolinat synthase, etc. For understanding the regulation mechanism of lysine synthesis in rice, we try to clone the lysine biosynthetic metabolism related gene, DHPS and asparaginase, from rice. We have isolated a rice DHPS genomic clone which contains an ORF of 1044 nucleotides (347 amino acids, Mr. 38, 381 daltons), an intron of 587 nucleotides and 5'and 3'-flanking regions by screening of rice genomic DNA library. Deduced amino acid sequence of mature peptide domain of GDHPS clone is highly conserved in monocot and dicot plants whereas that of transit peptide domain is extremely different depending on plant specie. Southern blot analysis indicated that GDHPS is located two copy gene in rice genome. The transcripts of a rice GDHPS were expressed in leaves and roots but not detected in callus tissues. The transcription level of GDHPS is much higher in leaves indicating enormous chloroplast development than roots. Genomic DNA clones for asparaginase genes were screened from the rice genomic library by using plaque hybridization technique. Twelve different genomic clones were isolated from first and second screening, and 8 of 12 clones were analyzed by restriction patterns and identified by Southern Blotting, Restriction enzyme digestion patterns and Southern blot analysis of 8 clones show the different pattern for asparaginase gene. Genomic Southern blot analysis from rice were done. It is estimated that rice has at least 2-3 copy of asparaginase gene. One of 8 positive clones was subcloned into the pBluescript SK(+) vector, and was constructed the physical map. For transformation of lysine rich storage protein into tobacco, soybean glycinin genes are transformed into tobacco. To examine whether glycinin could be stably accumulated in endosperm tissue, the glycinin cDNA was transcriptionally fused to an endosperm-specific promotor of the rice storage protein glutelin gene and then introduced into tobacco genomic via Agrobacterium-mediated transformation. Consequently the glycinin gene was expressed in a seed-and developmentally-specific manner in transgenic tobacco seeds. Glycinin were targeted to vacuole-derived protein bodies in the endosperm tissue and highly accumulated in the matrix region of many transgenic plant (1-4% of total seed proteins). Synthesized glycinin was processed into mature form, and assembled into a hexamer in a similar manner as the glycinin in soybean seed. Modified glycinin, in which 4 contiguous methionine residues were inserted at the variable regions corresponding to the C - teminal regions of the acidic and basic polypeptides, were also found to be accumulated similarly as in the normal glycinin. There was no apparent difference in the expression level, processing and targeting to protein bodies, or accumulation level between normal and modified glycinin. glycinin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.269-275
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• 2008

The avocado is a widely grown and consumed fruit that is high in nutrients and low in calories, sodium, and fats. In this study, antioxidant activities and induction of apoptosis by methanol extracts from sarcocarp, seed and peel of avocado were investigated in vitro. Contents of total polyphenols in methanol extracts from sarcocarp, seed and peel were 13.89, 137.12 and $223.45{\mu}g/mg$ respectively. Radical-scavenging activities of the methanol extracts were examined by using ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assay. The methanol extracts from the peel of avocado showed higher scavenging activities against DPPH, ABTS than those from sarcocarp and seed. Apoptosis in MDA-MB-231 cells mediated by the methanol extracts of avocado was associated with the increase of activation of caspase-3 and caspase-3 target protein, PARP. Therefore, with more researches on identification and action mechanism of active compounds, the methanol extracts from peel and seed of avocado is expected to be a natural source for the developments of functional food and medical agents to prevent human breast cancer.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.4
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• pp.145-157
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• 2017

SMEs play an important role in the domestic economy. Regarding competency to respond flexibly to unpredictable changes, agility of SMEs is more emphasized. Entrepreneurship orientation is an important factor in the source of SMEs that enable such competency. Entrepreneurial orientation refers to the tendency of a CEO or a member of a corporation to be innovative, risk-taking, and active in the face of various market opportunities. In other words, it refers to the tendency to be expressed in the activities of the entire company without regard to specific technologies or industries. Entrepreneurial orientation has a direct or indirect effect on business performance. Therefore, in this study, we conducted theoretical and empirical studies on the effect of entrepreneurial orientation of SME managers on business performance. Research hypotheses were derived through theoretical research. We focused on the mediating effect of innovation activity and tried to identify the mechanism that entrepreneurial orientation leads to business performance through product innovation and service innovation activity. We investigated whether innovativeness, proactiveness, and risk-taking, which are sub-variables of entrepreneurial orientation, affect business performance through product innovation and service innovation. We conducted a survey of SMEs in Busan and Kyungnam regions to examine the research hypotheses. The results show that product innovation and service innovation have mediating effects. The results of the study are as follows. Product innovation has mediating effect of innovativeness and risk-taking on business performance. Service innovation has been found to mediate innovativeness, proactiveness, and risk-taking on business performance. There was a difference in the mediation effect between the two innovations. Product innovation showed a low mediating effect and a large direct effect. On the other hands, service innovation is relatively more mediating than product innovation. The implications of the research results are derived in relation to the essential differences between product innovation and service innovation. Limitations of the study and directions for future research are presented.

• Journal of Life Science
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• v.22 no.12
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• pp.1688-1696
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• 2012

Oenanthe javanica has been used as a food source and also in traditional folk medicine for its detoxifying properties and anti-microbial effects since ancient times. In this study, we evaluated the effect and mechanism of O. javanica seed methanol extract (OJSE) on adipocyte differentiation by 3T3-L1 preadipocytes. Under non-toxic conditions, OJSE treatment resulted in a dose-dependent inhibition of lipid droplet generation and triglyceride accumulation by suppressing adipocyte differentiation, which are associated with the decreased expression of key proadipogenic transcription factors including CCAAR/enhancer binding protein ${\alpha}$, ${\beta}$ ($C/EBP{\alpha}$, $C/EBP{\beta}$) and peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$). OJSE also significantly inhibited proliferation and differentiation of 3T3-L1 preadipocytes through G1-phase arrest, indicating that OJSE blocked mitotic clonal expansion during adipocyte differentiation. Investigation of the alteration of G1 phase arrest-related proteins indicated a dose-dependent increase in the expression of p21 and reduction in expression of cyclin E, Cdk2, E2F-1 and phospho-Rb by OSJE. Taken together, these results suggest that OJSE inhibits adipocyte differentiation by blocking the mitotic clonal expansion, which is accompanied by preadipocyte cell cycle arrest.

• The Korean Journal of Petroleum Geology
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• v.2 no.2 s.3
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• pp.51-57
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• 1994

Analysis of the aeromagnetic data aquired by US Navy in the year 1969 permits us to predict a new sedimentary basin, Heugsan Basin, south of the known Gunsan Basin in Block Ⅱ. The basin appears to consist of three sub-basins trending NNW-SSE. The results of our analysis provide not only an independent assessment of the Gunsan Basin, but also new important information on the tectonic origin and mechanism for the two basins as well as for the entire region. The basin forming tectonic style is interpreted as rhombochasm associated with double overstepped left-lateral wrench faults. From the magnetic evidence, a few NE-SW trending major onshore faults are extended to the study area. We also interpreted the nature of the faults to be left-lateral wrenches. This new gross structural style is consistent with the results of recent Yeongdong Basin analysis by Lee. The senses of fault movement are also supported by the paleomagnetic evidence that the Philippine Sea had experienced an 80-degree clockwise rotation since the Eocene. Based on a 2 $\frac{1}{2}$ model study the probable maximum thickness of the sediments in the Gunsan Basin is approximately 7500 meters. We believe that the new Heugsan Basin was left unidentified because a high velocity layer may be overlying the basin. Because the overall structural configuration of the Heugsan Basin appears to be favorable for hydrocarbon accumulation, a detailed airborne magnetic survey is recommended in the area in order to verify the magnetic expression of this thick basin. A detailed subsequent marine gravity survey is also recommended in order to delineate the sedimentary section and to acquire supplemental data to the magnetic method only if an overlying high velocity layer is confirmed. Otherwise a high energy source seismic survey may be more effective.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.1
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• pp.11-18
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• 2002

Purpose: It is known that lactoferrin serves as a source of iron for H. pylori in gastric mucosa. This study was undertaken to investigate the relationship between lactoferrin and H. pylori infection coexistent with iron-deficiency anemia by determining the lactoferrin levels in gastric biopsy specimens, and by locating the major sites of lactoferrin expression, according to the presence or absence of iron-deficiency anemia. Methods: Fifty-five adolescents that underwent gastroduodenoscopy were divided into three groups: NL (n=19) for normal controls, HP (n=15) for patients with H. pylori, and IDA (n=21) for patients with H. pylori gastritis and coexisting iron-deficiency anemia. Histopathologic features were graded from to marked on the basis of the Updated Sydney System. The gastric mucosal levels of lactoferrin were measured by immunoassay. Immunohistochemical technique was used to allow identification of the location and quantification of the lactoferrin expression. Results: Lactoferrin levels in the antrum increased significantly, in proportion to, H. pylori density, polymorphonuclear cell infiltration, and chronic inflammation in the histologic specimens. Patients in the HP and IDA groups showed significantly increased mucosal levels of lactoferrin compared with that observed in the normal group (p=0.0001). The lactoferrin level in IDA group tended to be higher than that in the HP group (p=0.2614). The major sites of lactoferrin expression by immunohistochemistry were in glands and neutrophils within epithelium. Lactoferrin was stained weakly in NL, and strongly in HP and IDA. Conclusion: The lactoferrin sequestration in the gastric mucosa of IDA was remarkable, and this finding seems to give a clue that leads to the clarification of the mechanism by which H. pylori infection contributes to iron-deficiency anemia.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.

• Food Science and Preservation
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• v.18 no.3
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• pp.366-373
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• 2011

Recent studies suggested that Cheonnyuncho is a significant source of bioactive phenolic compounds, comparable to phytochemicals, including green tea and onion. In this study, the hot-water and 80% ethanolic extracts of Cheonnyuncho were assessed as to their total phenol content, total flavonoids content, antioxidant activity (DPPH radical-scavenging activity and reducing power), and anti-obesity activity. The results showed that the total phenol contents of the hot water extract and the 80% ethanolic extract were $16.52{\pm}3.87$ and $13.44{\pm}0.85$ mg GAE/g, respectively. The total flavonoids content was detected only in the 80% ethanolic extract, however, with a 778.08 ${\mu}g$ catechin equivalents/g content. The DPPH radical-scavenging activity and reducing power of the 80% ethanolic extract from Cheonnyuncho was significantly higher than those of the water extract (p < 0.05). During the adipocyte differentiation, the 80% ethanolic extract of Cheonnyuncho more significantly inhibited lipid accumulation and ROS production than the 3T3-L1 cells that were treated with hot water extract. Furthermore, the 80% ethanolic extract of Cheonnyuncho suppressed the mRNA abundance of the adipogenic transcription factor, $PPAR{\gamma}$ (peroxisome proliferator-activated receptor ${\gamma}$), and its target gene, aP2 (adipocyte protein 2). These results indicate that Cheonnyuncho extracts can inhibit adipogenesis through a mechanism that involves direct down regulation of $PPAR{\gamma}$ gene expression or via modulation of ROS production associated with radical-scavenging activities.

• Knowledge Management Research
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• v.22 no.3
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• pp.273-293
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• 2021

Due to the COVID-19 pandemic, the size of the e-commerce has been increased rapidly. This pandemic, which made contact-less communication culture in everyday life made the e-commerce market to be opened even to the consumers who would hesitate to purchase and pay by electronic device without any personal contacts and seeing or touching the real products. Consumers who have experienced the easy access and convenience of the online purchase would continue to take those advantages even after the pandemic. During this time of transformation, however, the size of information source for the consumers has become even shrunk into a flat screen and limited to visual only. To provide differentiated and competitive information on products, companies are adopting AR/VR and steaming technologies but the reviews from the honest users need to be recognized as important in that it is regarded as strong as the well refined product information provided by marketing professionals of the company and companies may obtain useful insight for product development, marketing and sales strategies. Then from the consumer's point of view, if the ratings of reviews are widely diverged how consumers would process the review information before purchase? Are non-converged ratings always unreliable and worthless? In this study, we analyzed how consumer's regulatory focus moderate the attitude to process the diverged information. This experiment was designed as a 2x2 factorial study to see how the variance of product review ratings (high vs. low) for cosmetics affects product attitudes by the consumers' regulatory focus (prevention focus vs. improvement focus). As a result of the study, it was found that prevention-focused consumers showed high product attitude when the review variance was low, whereas promotion-focused consumers showed high product attitude when the review variance was high. With such a study, this thesis can explain that even if a product with exactly the same average rating, the converged or diverged review can be interpreted differently by customer's regulatory focus. This paper has a theoretical contribution to elucidate the mechanism of consumer's information process when the information is not converged. In practice, as reviews and sales records of each product are accumulated, as an one of applied knowledge management types with big data, companies may develop and provide even reinforced customer experience by providing personalized and optimized products and review information.

• Publications of The Korean Astronomical Society
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• v.36 no.3
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• pp.47-63
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• 2021

Variability is one of the major characteristics of Active Galactic Nuclei (AGN), and it is used for understanding the energy generation mechanism in the center of AGN and/or related physical phenomena. It it known that there exists a time lag between AGN light curves simultaneously observed at different wavelengths, which can be used as a tool to estimate the size of the area that produce the radiation. In this paper, We present long term near-infrared variability of optically bright type 1 AGN using the Wide-field Infrared Survey Explorer data. From the Milliquas catalogue v6.4, 73 type 1 QSOs/AGN and 140 quasar candidates are selected that are brighter than 18 mag in optical and located within 5 degree around the ecliptic poles. Light curves in the W1 band (3.4 ㎛) and W2 band (4.6 ㎛) during the period of 2010-2019 were constructed for these objects by extracting multi-epoch photometry data from WISE and NEOWISE all sky survey database. Variability was analyzed based on the excess variance and the probability P_var. Applying both criteria, the numbers of variable objects are 19 (i.e., 26%) for confirmed AGN and 12 (i.e., 9%) for AGN candidates. The characteristic time scale of the variability (τ) and the variability amplitude (σ) were derived by fitting the DRW model to W1 and W2 light curves. No significant correlation is found between the W1/W2 magnitude and the derived variability parameters. Based on the subsample that are identified in the X-ray source catalog, there exists little correlation between the X-ray luminosity and the variability parameters. We also found four AGN with changing W1-W2 color.