• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.429-447
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• 1996

Transforming growth factor $-{\beta}$ is one of the polypeptide growth factors that mediate the activity of mesenchymal cells and regulate wound healing process via cell proliferation, migration and extracellular matrix formation. The purposes of this study is to evaluate the effects of transforming growth factor $-{\beta}$ on the protein synthetic activity of human periodontal ligament cells and human gingival fibroblasts. The cells which were prepared were primary cultured gingival fibroblasts and periodontal ligament cells from humans, and the fourth or sixth subpassage were used in the experiments. Cells were seeded and at a confluent state, 0, 0.5, I, 2.5, 5, 10 ng/ml $TGF-{\beta}$ and $2{\mu]Ci/ml\;[^3H]$ proline were added to the cells and cultured for 24 hours. Then, 1 and 5 ng/ml concentrations were selected and added to confluent cells and cultured for 24 and 48 hours. They were labeled with $2{\mu}Ci/ml\;[^3H]$ proline for 24 hours and a collagen assay was done by the Peterkofsky and Diegelman method. The results were presented as the mean disintegration per minute (dpm) per well and S.D. of four determinations, The results were as follows. : The total protein, collagen and noncollagenous protein synthesis in periodontal ligament cells and gingival fibroblasts were increased dose- dependently by transforming growth factor-p to 2.5-5 ng/ml concentration and decreased at 10 ng/ml concentration. The percent of collagen was slightly changed according to the concentration of transforming growth factor-po The effect of transforming growth $factor-{\beta}$ was not specific for collagen synthesis since it increased the total, noncollagenous and collagenous protein, simultaneously. In the comparison of protein synthetic activity between the human periodontal ligament cells and human gingival fibroblasts, the human gingival fibroblasts had higher activities than the human periodontal ligament cells at all times and concentrations of $TGF-{\beta}$. In the comparison of protein synthetic activity between the 24 hour effect and the 48 hour effect of $TGF-{\beta}$, the 48 hour cultured cells' synthetic activity decreased more than the 24 hour cultured cells at human periodontal ligament cells and human gingival fibroblasts. In conclusion, $TGF-{\beta}$ has important roles in the stimulation of protein synthesis in human periodontal ligament cells and human gingival fibroblasts. Thus, it may be useful for clinical application in periodontal regenerative procedures.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.443-454
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• 2013

Various metal ions (transition and base metals) incorporated MCM-41 catalysts can be synthesized using colloidal and soluble silica with non-sodium involved process. Transition metal ion-typically $V^{5+}$, $Co^{2+}$, and $Ni^{2+}$-incorporated MCM-41 catalysts were synthesized by isomorphous substitution of Si ions in the framework. Each incorporated metal ion created a single species in the silica framework, single-site solid catalyst, showing a substantial stability in reduction and catalytic activity. Radius of pore curvature effect was investigated with Co-MCM-41 by temperature programmed reduction (TPR). The size of metallic Co clusters, sub-nanometer, could be controlled by a proper reduction treatment of Co-MCM-41 having different pore size and the initial pH adjustment of the Co-MCM-41 synthesis solution. These small metallic clusters showed a high stability under a harsh reaction condition without serious migration, resulting from a direct anchoring of small metallic clusters to the partially or unreduced metal ions on the surface. After a complete reduction, partial occlusion of the metallic cluster surface by amorphous silica stabilized the particles against aggregations. As a probe reaction of particle size sensitivity, carbon single wall nanotubes (SWNT) were synthesized using Co-MCM-41. A metallic cluster stability test was performed by CO methanation using Co- and Ni-MCM-41. Methanol and methane partial oxidations were carried out with V-MCM-41, and the radius of pore curvature effect on the catalytic activity was investigated.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.27-39
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• 1991

The diffusion of Sr-85, Cs-137, Co-60 and Am-241 in compacted domestic bentonite was studied, using a diffusion cell unit in which diffusion took place axially from the center of cylindrical bentonite sample body. The effects of compaction density and heat-treated bentonite on diffusion were analysed. And the diffusion mechanism of radionuclide was also analysed by evaluating the measured diffusivity of anion Cl-36. The apparent diffusivities obtained for Sr-85, Cs-137, Co-60 and Am-241 were $l.07{\times}10^{-11},\;6.705{\times}10^{-13},\;l.226{\times}10^{-13}\;and\; l.310{\times}10^{-14}m^2/sec$, respectively. When the as-pressed density of bentonite increased from $1.8\;to\;2.0g/cm^3$, the apparent diffusivity of Cs-137 decreased by quarter. In the case of bentonite heat-treated to $150^{\circ}C$, no significant change in diffusivity was observed, which showed the possibility that the domestic bentonite could be used as a chemical barrier to retard the radionuclide migration at below $150^{\circ}C$. From the calculated pore and surface diffusivity, the surface diffusion due to the concentration gradient of radionuclide sorbed on the solid phase was found to dominate greatly in total transport process.

• Journal of the Economic Geographical Society of Korea
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• v.7 no.1
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• pp.83-96
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• 2004

Location of firms and construction of new industrial complex generally have an effect on the population change of region. This paper focuses on the population change of Gwangyang city, in particular, the relationship between location of new firm, Gwangyang Works of POSCO, and population change of region. The first construction of Gwangyang Works of POSCO was finished in 1987. The number of population of Gwangyang city increased from 78,478 individuals of 1981 to 138,468 individuals of 2001, and the number of household also increased from 14,917 household of 1981 to 43,176 household of 2001 with the location and construction process of Gwangyang Works of POSCO. The growth of population was greatly revealed during the period of 1987 through 1991 with social increase of pouplation transferred into Gwangyang city from another area. This period related with the completion of Gwangyang Works of POSCO. In addition, population increase was mainly appeared in Eastern Gwangyang area, neighboring area to Gwangyang Works 13,211 peoples of 1981 to 74,956 peoples of 2001. Therefore, it is clear that location of Gwangyang Works of POSCO had a significant impact on the change of population structure and population growth of Gwangyang city since 1981.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.2
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• pp.250-263
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• 2006

Statement of problem: Ti-alloy has been used widely since it was produced in the United States in 1947 because it has high biocompatibility and anticorrosive characteristics. Purpose: The pure titanium, however, was used limitedly due to insufficient mechanical charateristics and difficult manufacturing process. Our previous study was focused on the development of a new titanium alloy. In the previous study we found that the Ti-Ta-Nb alloy had better mechanical characteristics and similar anticorrosive characteristics to Ti-6Al-4V Material and methods: In this study, the cytotoxicity of the Ti-Ta-Nb alloy was evaluated by MTT assay using MSCs(Mesenchaimal stem cells) and L929 cells(fibroblast cell line). The biocompatibility of the Ti-Ta-Nb alloy was performed by inserting the alloy into the femur of the rabbits and observing the radiological and histological changes surrounding the alloy implant. Results: 1. In the cytotoxicity test using MSCs, the 60% survival rate was observed in pure titanium, 84% in Ti-6Al-4V alloy and 95% in Ti-10Ta-10Nb alloy. 2. In the animal study, the serial follow-up of the radiographs showed no separation or migration revealing gradual bone ingrowth surrounding the implants. Similar radiographic results were obtained among three implant groups pure titanium, Ti-6Al-4V alloy and Ti-10Ta-10Nb alloy. 3. In the histologic examination of the bone block containing the implants. the bone ingrowth was prominent around the implants with the lapse of time. There was no signs of any tissue rejection, degeneration, or inflammation. Active bone ingrowth was observed around the implants. In the comparison of the three groups, the rate of bone ingrowth was better in the Ti-10Ta-10Nb alloy group than those in pure titanium group or Ti-6Al-4V alloy group. In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects. Conclusion: In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects.

• Journal of the Korean association of regional geographers
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• v.15 no.6
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• pp.820-833
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• 2009

Multiculturalism in education are different from each countries, It is needed to practice multicultural education in many fields facing changes to multicultural society in Korea. This study demonstrates on the relationship of social friendliness and stereotypical attitudes toward Saeteomins (North Korean refugees) to the knowledge of North Korea. Saeteomins are special in the respect of linguistic and ethnic homogeneity of Korea. They have to adapt themselves to new circumstances like other immigrants from abroad. At the same time they have cultural senses of difference to live in a divided country in spite of ethnic homogeneity. It is important to get openminded attitudes to be receptive to cultural diversity in the respect of getting multicultural sensitivity. On account of a growing migration of Saeteomins family, Saeteomin students have difficulties in adapting to Korean society. This study focuses on the point of middle school (general) students' view to Saeteomin students, who have experiences to meet each other. There are three categories of contents knowledge, common sense of North Korea and social issues related to North Korea in this paper. All of them are significant to social friendliness and stereotypical attitudes toward Saeteomins to the knowledge of North Korea. That is important point to contents construction in curriculum about North Korea. This study is meaningful to find the potential to link contents knowledge of subject to multicultural education practice in the process of curriculum change especially in relation to the knowledge of North Korea in 2007.

• Ecology and Resilient Infrastructure
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• v.1 no.2
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• pp.68-81
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• 2014

In this study, the numerical simulation regarding the process and characteristics of topography change due to the vegetation recruitment and growth was carried out by adding the vegetation growth model to two-dimensional flow and sediment transport models. The vegetation introduction and recruitment on the condition for developing an alternate bar reduced the bar migration. The vegetated area and channel width changes were more significantly influenced by changes in upstream discharge rather than the duration of low flow. When the upstream discharge decreased, the vegetation area increased and the channel width decreased. The vegetation introduction and recruitment on the condition for developing a braided channel significantly influenced the characteristics of topography changes. In the braided channel, vegetation reduced the braided index, and when the upstream discharge decreased significantly, the channel topography was changed from the braided channel to the single channel. The vegetation area decreased as the upstream discharge increased. The channel width decreased significantly after the vegetation was introduced and it also decreased as the upstream discharge decreased. It was confirmed through the numerical simulation that a decrease in flood discharge accelerated the vegetation introduction and recruitment in the channel and this allowed to confirm its influence on the characteristics of topography changes qualitatively.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.229-246
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• 1997

Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.116-127
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• 2015

The phenomenon of international migration since the 1980s comes to be born 'multi-cultural families support law' due to the foreign workers' inflow into labor market and to a rise in married female immigrants caused by globalization and diversification. Accordingly, the purpose of this study is to examine who are participants? given being led to the enactment of 'multi-cultural families support law' by which the social issue called multi-cultural family is highlighted as the public agenda. Also, the mobilization will be selected and explained among three types in mobilization model, outside initiative model, and inside access model in the process of driving by confirming it as the government's formal agenda out of social issues. With having the case characteristics in mind, the aim is to research by choosing a case analysis method that uses research theses & books, newspaper, daily newspaper, election pledges, civic group, internet, and seminar data based on the existing theory and model. The temporal scope is limited to the one from the time as saying "revise the Overseas Korean Act of opposing the banishment of migrant workers" in November 2003 to February 2008 when 'multi-cultural families support bill(alternative plan)' is legislated with agreement by the 7th plenary session for the 271th provisional session of the National Assembly.

• Korea journal of population studies
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• v.31 no.3
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• pp.131-157
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• 2008

The purpose of this study was to examine the difference in depression level of Japanese, Chinese and Vietnamese wives who are residing in Korean society. Special focus was taken to compare the differences in terms of the origin of nationality. Guided by the role theory, we analyzed the effect of parental role and work role on depression of foreign wives. Also we considered the social resources, ethnic characteristic that are well-known to be associated with the role performance, in this study. The data came from the sample of 524 foreign wives case (Japanese 35%, Chinese 31%, Vietnamese 34%). The result show us that depression level is different by origin of nationality of foreign wives: Vietnamese wives were more depressed compare to Japanese or Chinese wives. The effects of two social role on depression were significant even if the social resources and ethnicity are considered in the model. However, the strength of the effect of social roles were different by one another: having a job was especially effective to decrease the Chinese wife's depression level, while for the Vietnamese wives, parental role was essential to lower the depression level. In addition, the social determinants of depression were differ by the nationalities of wives. The results imply that the social adaptation process of foreign wife may be varied by the origin of nationality.