• KSBB Journal
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• v.13 no.4
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• pp.438-443
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• 1998

Effects of various environmental factors on cell size index(FCW/DCW) in Thalictrum rugosum. Lithospermum erythrorhizon and Taxus cuspidata plant cell suspension cultures were investigated. Time course change of cell size index were also observed. In batch cultures, FCW/DCW increased according to the decrease of sugar concentration. For short-term experiment within 24 hr, FCW/DCW value could be reduced significantly by increasing sugar concentration. When an osmoticum such as mannitol was added, FCW/DCW converged to a low value. Therefore, it was confirmed that osmolality of the medium was important in determining cell size or water content of the cells. Inorganic salts or treatment with organic solvent also exhibited some effect on the cell size index. However, pH and centrifugal force did not show any influences. On the other hand, it was found that the addition of Pluronic F-68 reduced FCW/DCW. By combining these results effectively, it may be possible to increase the cell concentration in high density culture to a higher extent.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.10a
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• pp.47.1-47
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• 2001

One of the problems associated with in vitro culture of primordial gern cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of the porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally, \ulcorner2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p<0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layer, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of \ulcorner2-macroglobulin and antioxidatns can increase the number of PGCs in vitro by suppressing apoptosis.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.47-47
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• 2001

One of the problems associated with in vitro culture of primordial germ cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally,？ 2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p〈0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layers, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of ？2-macroglobulin and antioxidants can increase the number of PGCs in vitro by suppressing apoptosis.

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.25-32
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• 2008

In order to estimate the necessity of refrigerated storage of fresh seafood for short-term storage, and evaluate the effect of refrigerated storage on pen shell Atrina pectinata and clam Ruditapes philippinarum collected from Jang-su of Deukryang Bay and I-mok of Sunchen Bay in South Korea, the counts of coliform, Escherichia coli and total aerobic bacteria in A. pectinata and R. philippinarum under non-refrigerated $(28{\pm}1^{\circ}C)$ and refrigerated storage conditions $(4{\pm}1^{\circ}C)$ were determined. The results indicated that the storage at temperature of $4^{\circ}C$ possessed significant effects on inhibiting bacterial growth in live seafood. And refrigerated storage had different effect on A. pectinata and R. philippinarum. Different species and culture environments significantly influenced the initial and ultima bacteria counts. This study confirmed that refrigerated storage for short-term storage of live seafood was necessary, and indicated that the effect of refrigerated storage was influenced by comprehensive effectors.

• Herbal Formula Science
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• v.14 no.2
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• pp.86-96
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• 2006

Objectives : This study wad designed to elucidate the short term effect of Rossa rugosae Radix on proliferation, differentiation and maturation of 3T3-L1 Preadipocyte. Methods : 3T3-L1 preadipocytes obtained from Korean Cell line Bank were cultured in a Dulbecco's modified eagle medium(DMED) culture colution containing 10% fetal bovine serum(FBS) and various concentration of aqueous extract of Rossa rugosae Radix on proliferation, differentiation and maturation of 3T3-L1 preadipocytes were investigate after treatment for 24 hours b measuring MTT, Oil Red O and latate dehydrogenase activity.. Results : The Rossa rugosae Radix extract inhibited significantly the proliferation of 3T3-L1 preadipocytes and tended to increase latate dehydrogenase activity in the media of differentiated 3T3-L1 preadipocytes & matured 3T3-L1 preadipocytes. the extract also inhibit the lipid accumulation of differentiated and maturaion of 3T3-L1 preadipocytes, suggesting that Rossa rugosae Radix has anti-obesity effect: however further in vivo study is needed to demonstrate its pharmacological effects.

• Korea journal of population studies
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• v.34 no.1
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• pp.53-72
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• 2011

This study analyzes the effects of life course events and labor market conditions on the duration of career interruption among Korean women. The data were drawn from 'A Survey on the Women's Employment Interruption in Korea' conducted by the Korean Ministry of Gender Equality in 2009(currently the Korean Ministry of Gender Equality and Family). This study categorizes the duration of career interruption into three categories: (1) short term interruption(less than 12months), (2) short-medium term interruptio(12-35 months), (3) intermediate term interruption(36-59 months), (4) long term interruption(longer than 36 months), and then analyzes how demographic factors, labor market condition, and life events shape the timing of re-entry into the labor market among women. According to the findings, the jobs that are conducive to combining market work and mother's role expedite women's return to the labor market. Further, the younger, higher the level of human capital, and higher monthly wages that women earned before leaving the labor market, women are likely to experience short-term interruption(less than 12 months) rather than long-term interruption(longer than 60 months). Women who left from the labor market to care for kids are also likely to return to the labor market. However, women who have preschoolers are likely to experience long-term career interruption. These findings highlight the role of family supportive culture at the workplace in order for women to continue their employment while intensive family formation period. Furthermore, the finding that the discriminatory practices against women, in particular mother workers at the workplace lead women to exit from the market work calls for attention to establish family friendly workplace.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.215-223
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• 2019

Driving after drinking is highly likely to cause accidents due to lack of responsibility and poor judgment. South Korea is seeking a sentence for accidental drinking accidents. The suspended jail term for drunk drivers accounts for more than 70 percent of the total. However, those who come to the probation office during the probation period are involuntary, subject to little motivation for change, and the large-scale, collective, and short-term education offered to them is limited in preventing re-off. In addition to small group and long-term education, we conducted intensive short-term interventions to see changes in drinking habits in three months. In the long run, the effectiveness of drinking control will be demonsstrated, making a difference in improving the programs offered to drunk drivers in the future. Drunk driving accouts for a very high percentage of the causes of traffic accidents, which, like many countries around the world, should make efforts to prevent and punish drunk driving.

• BMB Reports
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• v.36 no.6
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• pp.565-571
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• 2003

The locomotor responses of human peripheral blood neutrophils and lymphocytes were measured by the change from spherical to polarized shapes in the presence of endotoxins (lipopolysaccharide, LPS) of enteric pathogens: S. dysenteriae type 1, V. cholerae Inaba 569B, S. typhimurium, and K. pneumoniae. We reported earlier that these endotoxins are chemotactic factors for the neutrophils since they stimulated cell polarization within a few minutes of incubation. Endotoxins had an inhibitory effect upon neutrophil phagocytosis of opsonized yeast and the cells engulfed fewer yeasts. Interestingly, endotoxins increased neutrophil adhesion to clean glass surfaces, but stimulated the cells to exhibit increased random locomotion (chemokinesis) through cellulose nitrate filters and show an enhanced ability to reduce nitroblue tetrazolium (NBT) dye. Unlike neutrophils, lymphocytes direct from blood do not show polarized morphology towards chemotactic factors but the cells acquire locomotor capacity during 24-72 h culture with mitogens such as phytohemagglutinin (PHA), phorbol myristate acetate or concanavalin A. Stimulation of blood lymphocytes with endotoxins did not induce cell polarization in short-term but long-term culture resulted in an increase in the proportion of polarized cells that acquired locomotor morphologies. The majority of these cells were identified as esterase negative B-lymphocytes that migrated through filters. Despite the optimum time of incubation for each of these cell types being different, we found that lymphocytes respond to much lower concentrations of endotoxins than the neutrophils. These findings suggest that endotoxins of enteric pathogens modulate the functions of human blood neutrophils and lymphocytes.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.101-108
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• 2020

One difficulty in language learning is the training of reading ability. The improvement on this ability directly affects the process and effect of language learning. At the same time, there are numerous difficulties in actual learning and teaching. Depending on current research, there is two ideas that can utilize to enhance the reading efficiency of learners. One is to amend objective factors; the other is to change subjective factors. Compared with the two ideas, idiosyncratic factors are more manipulable and controllable, so it is more valuable to conduct researches on this. But among the many subjective factors, the degree of their effectiveness is not the same, so this article attempts to compare and analyze the driving effects of two important subjective factors (peer-driven and task-driven) on reading performance. The results show that both factors can have a positive impact on reading comprehension, but different in driving effects. The task-driven has obvious short-term effectiveness; while peer-driven needs to establish its long-term effect on the basis of early coordination and cooperation among team members. Therefore, in order to maximize the achievement of learning, it is necessary to combine strengths and avoid weaknesses according to the characteristics of two factors, so as to help learners improve reading ability most efficiently.

• International Journal of Advanced Culture Technology
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• v.7 no.3
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• pp.97-102
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• 2019

This study suggests a solution of an incentive system from the viewpoint of the external effect on the renting of firefighting qualifications and on rental agencies. Currently, the Human Resources Development Service of Korea does not have a penalty for neglecting to perform a search into qualification lending and rental agencies. In the short term, the penal clause should be strengthened so that companies and qualification holders cannot borrow or lend their qualifications. In addition, the Human Resources Development Service of Korea will increase the number of personnel dedicated to investigating the loaning of qualifications. It is necessary for the government to establish a penalty for neglecting to investigate the lending of qualifications for the Human Resources Development Service of Korea. In the long term, the state needs to make only minimal regulations. Also, the state needs to make companies and qualification holders feel like they benefit more when they are not borrowing or lending qualifications. The anticipated effect of this study is that the government will intervene appropriately by applying firefighting qualifications according to market principles. It can also be used as a basis for the revision of related laws on the renting of national technical qualification certificates and the investigation of rental agencies.