• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.129-142
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• 2002

Epithelial-mesenchymal interaction plays a important role in cell growth and differentiation. This interaction is already well known to have an importance during the organ development as well as cell growth and differentiation. However, in vitro experimental model is not well developed to reproduce in vivo cellular microenvironment which provide a epithelial-mesenchymal interaction. Because conventional monolayer culture lacks epithelial-mensenchymal interaction, cultivated cells have an morphologic, biochemical, and functional characteristics differ from in vivo tissue. Moreover, it's condition is not able to induce cellular differention due to submerged culture condition. Therefore, the aims of this study were to develop and evaualte the in vitro experimental model that maintains epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally reconstituted oral keratinocytes by histological and immunohistochemical analysis. The results were as follow; 1. Gingival keratinocytes reconstituted by three-dimensional organotypic culture revealed similar morphologic characteristics to biopsied patient specimen showing stratification, hyperkeratinosis, matutation of epithelial architecture. 2. Connective tissue structure was matured, and there is no difference during stratification period of epithelial 3-dimensional culture. 3. The longer of air-exposure culture on three-dimensionally reconstituted cells, the more epithelial maturation, increased epithelial thickness and surface keratinization 4. In reconstitued mucosa, the whole epidermis was positively stained by anti-involucrin antibody, and there is no difference according to air-exposured culture period. 5. The Hsp was expressed in the epithelial layer of three-dimensionally cultured cells, especially basal layer of epidermis. The change of Hsp expression was not significant by culture stratification. 6. Connexin 43, marker of cell-cell communication was revealed mild immunodeposition in reconstitued epithelium, and there is no significant expression change during stratification. These results suggest that three-dimensional oragnotypic co-culture of normal gingival keratinocytes with dermal equivalent consisting type I collagen and gingival fibroblasts results in similar morphologic and immunohistochemical characteristics to in vivo patient specimens. And this culture system seems to provide adequate micro-environment for in vitro tissue reconstitution. Therefore, further study will be focused to study of in vitro gingivitis model, development of novel perioodntal disease therapeutics and epithelial-mensenchymal interaction.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.236-259
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• 2010

The examination of sediment distribution in Seongryu Cave shows existence of rocks contrasting with Joseon Supergroup contrary to existing knowledge. Contrasting especially with the Taeback Group, Daegi Formation, Hwajeol Formation, and Dongjeom Formation has been observed. Unlike Taeback area where Dumugol Formation and Makgol Formation are observed on top of Dongjeom Formation, the rocks of this area are not clear in its separation between the two, so that it was named Geunnam Formation. Seongryu Cave has been developed in this Ordovician Geunnam Formation of the Joseon Supergroup. The cave, mostly horizontal, runs in the NE-SW direction, and contains three lakes. The main passage and branches are about 330 m and 540 m, respectively, making the total length of the cave about 870 m (show cave area = 270 m). Through underwater examination, about 85 m-long underwater passage was newly discovered. Various speleothem such as soda straw, stalactite, stalagmite, column, flowstone, rimston, cave shield, cave coral, curtain, bacon sheet, cave pearl, cave flower, helictite and calcite raft can be found in the cave. There are sections with constant flow of cavern water, but the majority of cavern water in the cave come from the ceiling. The most important discovery in this study is the presence of various speleothem in the submerged part of cave passages. Traces of corrosion and/or erosion can be observed in the speleothem in the submerge passage.

• Journal of Korea Foundry Society
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• v.41 no.6
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• pp.505-515
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• 2021

Creep properties of directionally solidified Ni-based superalloy CM247LC under various temperature and stress conditions have been investigated. In the heat-treated specimen, some portion of eutectic γ-γ' remained, and uniform cubic γ' was observed in the dendrites. At low temperature (750℃) and high stress condition, a large amount of deformation occurred during the primary creep, while the tertiary creep region accounted for most of the creep deformation under high temperature and low stress condition. γ' particles are sheared by dislocation dissociated into super lattice partial dislocations separated by stacking faults at 750℃. No stacking faults in γ' were found at and above 850℃ due to the temperature dependence of the stacking fault energy. Raft structure of γ' was found after creep test at high temperature of 950℃ and 1000℃. At 850℃, the deformation mechanism was shown to be dependent on the stress condition, and so rafting was observed only under low stress condition.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.647-655
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• 1997

We evaluated the feasibility and safety of this method by reviewing the early outcome of the patients who underwent coronary artery bypass grafting(CABG) utili ing parallel sequential anastomoses with saphenous vein grafts, comparing with the outcome of the patients revascularized with grafts having only single distal anastomosis. During the one-year period of 1995, a total of 79 patients underwent isolated CABG, among whom 39 patients with sequential vein grafts(sequential group) and 40 patients without sequential grafts(non-sequential group). There was no difference between the two groups in terms of preoperative status, except in the extent of the coronary disease; 87.2% of the sequential group and 45.0% of the non-sequential group had left main andlor triple vessel involvement. 318 distal coronary anastomoses were done; 198 for the sequential group(5.1/patient) and 120 for the non-sequential group(3.0/patient). In the sequential group, the mean durations of cardiopulmonary bypass and aortic clamp per one distal anastomosis were 33.5 and 21.1 minutes, respectively. In the non-sequential group, these were 41.8 and 22.7 minutes. There were two operative deaths, both in the non-sequential group. There was no difference in the incidence of postoperative complications including myocardial infarction. During the follow-up period(2 to 15 months), 8 patients(3 in the sequential and 5 in the nonsequential group) complained of residual or recurrent angina. Comparison of preoperative and postoperative ."'Thallium myocardial perfusion scans in 30 patients showed improved or normal perfusion reserve in 83.3% of segments bypassed with sequential grafts and 82.5% of segments bypassed with non-sequential graft(5), These results show that, utilizing parallel sequential anastomoses with saphenous vein grafts, we could achieve satisfactory short-term clinical results in patients with extensive coronary stenoses. So, we conclude that this technique is a safe, technically feasible strategy for CABG, which can achieve the aim of complete myocardial revascularization with a limited length of graft.raft.

• Korean Journal of Cleft Lip And Palate
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• v.3 no.1
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• pp.23-31
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• 2000

Objective: When an alveolar cleft is too large to close with adjacent mucobuccal flaps or large secondary fistula following a primary bilateral palatoplasty exists, a one-stage procedure for bone grafting becomes challenging. In such a case, we used the tongue flap to repair the fistula and cleft alveolus in the first stage, and bone grafting to the cleft defect was performed in the second stage several months later. The purpose of this paper is to report our experiences with the use of an anteriorly-based Y-shaped tongue flap to fit the palatal and labial alveolar defects and the ultimate result of the bone graft. Patients: A series of 14 patients underwent surgery of this type from January 1994 to December 1998.The average age of the patients was 15.8 years old (range: 5 to 28 years old). The mean period of follow-up following the 2nd stage bone raft operation was 45.9 months (range: 9 to 68 months). In nine of the 14 cases, the long-fork type of a Yshaped tongue flap was used for extended coverage of the labial side alveolar defects with the palatal fistula in the remaining cases the short-forked design was used. Results: All cases demonstrated a good clinical result after the initial repair of cleft alveolus and palatal fistula. There was no fistula recurrence, although Partial necrosis of distal margin in long-forked tongue flap was occurred in one case. Furthermore, the bone graft, which was performed an average of 8 months after the tongue flap repair, was always successful. Occasionally, the transferred tongue tissue was bulging and interfering with the hygienic care of nearby teeth; however, these problems were able to be solved with proper contour-pasty performed afterwards. No donor site complications such as sensory disturbance, change in taste, limitations in tongue movement, normal speech impairments or tongue disfigurement were encountered. Conclusion: This two-stage reconstruction of a bilateral cleft alveolus using a Y-shaped tongue flap and iliac bone graft was very successful. It may be indicated for a bilateral cleft alveolus patient where the direct closure of the cleft defect with adjacent tissue or the buccal flap is not easy due to scarred fibrotic mucosa and/or accompanied residual palatal fistula.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.43-50
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• 2021

Growth tests on the Yuldo, Supum1 and Supum2 cultivars of Pyropia dentata were performed at the Eoran and Imha aquafarm, Haenam in Jeollanamdo, from October to December in 2017. The mean water temperature ranged from 5.4 to 26.4 ℃. In Eoran aquafarm (flating raft method), dissolved total nitrogen (DTN), dissolved total phosphorus (DTP), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) ranged from 0.091 to 0.181 mg/L, 0.007 to 0.019 mg/L, 0.114 to 0.187 mg/L, 0.008 to 0.033 mg/L and 0.200 to1.000 mg/L, respectively. In Imha aquafarm (fixed pold method), DTN, DTP, TN, TP and COD ranged from 0.118 to 0.276 mg/L, 0.005 to 0.024 mg/L, 0.155 to 0.305 mg/L, 0.009 to 0.042 mg/L and 0.300 to1.400 mg/L, respectively. In order to investigate the number of conchospores attached on the Pyropia net, which was cut into about 4cm long. The mean number of conchospores of Yuldo, Supum1 and Supum2 cultivars were 39.5, 26.5, 72.5, respectively. Young thalli were harvested two times at Eoran aquafarm, and three times at Imha aquafarm. In eoran aquafarm, the mean thallus length of Yuldo, Supum1 and Supum2 cultivars were 49.9, 46.0, 42.0 cm on October and 163, 126.0, 263.0 cm on November, respectively. The mean thallus width of Yuldo, Supum1 and Supum2 cultivars were 5.8, 4.6, 11.5 cm on October and 20.9, 11.5, 14.0 cm on November, respectively. In Imha aquafarm, the mean thallus length of Yuldo, Supum1 and Supum2 cultivars were 119.0, 60.9, 71.0 cm on October, 196.0, 132.0, 262.0 cm on November and 187.0, 281.0, 296.0 cm on December, respectively. The mean thallus width of Yuldo, Supum1 and Supum2 cultivars were 4.2, 3.4, 3.1 cm on October, 8.9, 6.2, 6.6 cm on November and 11.7, 11.6, 9.4 cm on December, respectively. In eoran aquafarm, contents of moisture, crude ash, crude lipid, crude protein and carbohydrate of three cultivars ranged from 11.64 to 20.15, 19.54 to 21.19, 0.00 to 0.18, 29.78 to 37.81, 29.16 to 29.71, respectively. In Imha aquafarm, contents of moisture, crude ash, crude lipid, crude protein and carbohydrate of three cultivars ranged from 8.43 to 9.15, 11.42 to 17.49, 0.00 to 0.00, 31.90 to 37.54, 36.30 to 42.24, respectively.