• 수산해양기술연구
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• 제47권3호
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• pp.241-247
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• 2011

Marine casualties of vessel are said to be in most case caused by human error, but it would be valid for the assumption that the ship is built with high quality and then should be acceptable to the safety standards. It means that the inherent characteristics of a ship should be the first consideration on the safety of ship. Therefore it is basically necessary for navigator to grasp the inherent stability of his ship and ensure that the ship complies with the minimum statutory standards of stability. This study is to realize the stability of the Korean offshore large purseiner varying with loading conditions by the inclining data and some calculations. The author compared the stability of the ship with IMO criteria and domestic rule, and proposed some improvement for the safety of the ship. The results are summarized as follows ; The values of GM of the ship according to the loading condition in navigation satisfy both of the IMO criteria and the domestic rule, but in case of the area under the GZ curves between the heel angles of $30^{\circ}$ and $40^{\circ}$, and the heel angle occuring the maximum righting lever not satisfy the IMO rule at the fishing ground departure and arrival conditions in the haul in net situation. The initial metacentric height of the ship is very large, but the range of stability and the occurring angle of the maximum GZ are very small, so even small inclining can bring about the beam end. The best method of improvement for that is to increase the freeboard of the model among the variables.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.400-405
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• 2004

Angiogenesis inhibition is major concern to cancer chemotherapy and many studies about compound inhibiting angiogenesis is in progression. The long-known preventive effect of plant-based diet on tumorigenesis and other chronic diseases is well documented. Especially soy extract, genistein, is known to be potent angiogenesis inhibitor and prevent development and progression of tumor. In the present study, the effect of angiogenesis on tumorigenesis and chemopreventive effect of genistein by angiogenesis inhibition in hamster buccal pouch oral carcinigenesis model induced by 7.12-dimethylbenza(a)nthracene (DMBA) was studied. Forty eight Syrian Golden young adult hamsters (150-200 gm) were divided into two groups. In control group, 0.5% DMBA in heavy mineral oil was applied to hamster buccal pouch three times a week and in experimental group, 0.1 mg of genistein is administered orally everyday in addition to DMBA application. The animals were euthanized from 2 weeks to 16 weeks with interval of 2 week. H&E staining and immunohistochemistry was performed to evaluate microvessel density by using factor VIII-related antigen and avidin-biotin technique. Microvessels per area was quantified and compared between control and experimental group statistically. The results were as follows. 1. Microvessel density was increased time dependently in both groups and especially the increase was significant from 12 weeks to 16 weeks. 2. When comparing both group, the experimental group showed significantly low microvessel density than control group in 12 weeks (p=0.043), 14 weeks (p=0.050), 16 weeks (p=0.037). Based on these results, it was concluded that genistein influenced oral carcinogenesis by angiogenesis inhibition.

• 해양환경안전학회지
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• 제24권1호
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• pp.1-9
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• 2018

선박의 안전 확보를 위해 준수해야 하는 IMO 복원성 규칙에는 복원정 곡선(GZ Curve) 등에 관한 내용이 다양하게 규정되어 있다. 이 IMO 복원성 규정에는 다양한 항목의 만족 기준이 제시되고 있으나, 선박을 운항하는 선장에게 선박의 복원성능을 종합적이며, 간편하게 제공할 수 있는 방법은 부재한 상황이다. 이를 위해 본 연구에서는 복원성을 하나의 값으로 표현할 수 있는 지수를 개발하였다. IMO에서 규정한 선박의 6가지 복원성 항목과 대상선박의 적재상황에 따른 복원성 계산결과를 바탕으로 지수산정식이 도출되었다. 또한 개발된 지수산정식을 적용하여 다양한 화물 적재 상황별 복원성 지수(Stability Index)를 계산하였으며, 복원성능의 전반적인 정도를 수치적으로 적절하게 설명할 수 있음을 검증하였다. 이는 선박의 선장에게 복원성 평가하고 판단하는데 도움을 줄 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9667-9672
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• 2014

Background: Pancreatic adenocarcinoma is a malignant gastrointestinal cancer with significant morbidity and mortality. Despite severe side effects of chemotherapy, the use of immunotherapy combined with chemotherapy has emerged as a common clinical treatment. In this study, we investigated the efficacy of the combined doxorubicin and interferon-${\alpha}$ (IFN-${\alpha}$) therapy on murine pancreatic cancer Panc02 cells in vitro and in vivo and underlying mechanisms. Materials and Methods: A Panc02-bearing mouse model was established to determine whether doxorubicin and interferon-${\alpha}$ (IFN-${\alpha}$) could effectively inhibit tumor growth in vivo. Cytotoxicity of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) was evaluated using a standard LDH release assay. To evaluate the relevance of NK cells and CD8 T cells to the combination therapy-mediated anti-tumor effects, they were depleted in tumor-bearing mice by injecting anti-asialo-GM-1 antibodies or anti-CD8 antibodies, respectively. Finally, the influence of doxorubicin+interferon-${\alpha}$ (IFN-${\alpha}$) on the ligands of NK and T cells was assessed by flow cytometry. Results: The combination therapy group demonstrated a significant inhibition of growth of Panc02 in vivo, resulting from activated cytotoxicity of NK cells and CTLs. Depleting CD8 T cells or NK cells reduced the anticancer effects mediated by immunochemotherapy. Furthermore, the doxorubicin+IFN-a treatment increased the expression of major histocompatibility complex class I (MHC I) and NKG2D ligands on Panc02 cells, suggesting that the combined therapy may be a potential strategy for enhancing immunogenicity of tumors. All these data indicate that the combination therapy using doxorubicin and interferon-${\alpha}$ (IFN-${\alpha}$) may be a potential strategy for treating pancreatic adenocarcinoma.

• 대한수의학회지
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• 제38권2호
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• pp.386-393
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• 1998

The study was performed to investigate the histological findings and the appearances of positive cells by immunohistochemical methods using proliferating cell nuclear antigen (PCNA) antibody and apoptotic kit in diethylnitrosamine (DEN) -induced rat liver cancer model. Forty four male rats (Sprague Dawley), initially 5 to 6 weeks of age and 120 to 150gm in body weight were continuously were given with water containing 0.01% DEN for 13 weeks and 3~6 rats per week were randomly sacrified at intervals of a week from 8 weeks to 17 weeks. The interlobular connective tissues in the rat livers were proliferated at early 8 weeks. The vaccuolated or fatty degenerated liver cells were focally distributed and then widely distributed with the passage of weeks and the liver cells with large vacuoles tended to be crowded in focal areas, and the liver cells in some lobules were transformed into small or eosinophilic polyhedral large cells. The hepatocellular carcinoma and the cholangiocarcinoma were simultaneously developed in same liver and tended to be markedly developed after 12 weeks but the development of carcinoma in some livers at same week were less or more advanced as 3~5 week intervals. The regions with more number of positive cells by PCNA antibody or apoptotic kits in livers were ranked as following order ; small hepatocellular carcinoma regions, cholangiocarcinoma regions, trabecular or acinar type carcinoma regions, and large liver cell regions. The numbers of the positive cells by PCNA antibody were more numerous than those by apoptotic kit. So these findings suggested that the volumes and weights of the livers were increasing by more many proliferating of carcinoma cells on the above ordered regions.

• Journal of Periodontal and Implant Science
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• 제31권1호
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• pp.91-109
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• 2001

The purpose of this study is to evaluate histologically the resorption and tissue response of various resorbale membranes used for guided tissue regneration procedures, using a subcutaneous model on the dorsal surface of the rat. In this study, 12 Sprague-Dawley male rats(mean BW 150gm) were used and the commercially available materials included dense collagen membrane, freeze-dried bovine dura mater loos collagen membrane, PLA/PLGA membrane. Animals were sacrificed at 3, 6 and 8 weeks after implantation of various resorbable membranes. Specimens were prepared with Hematoxylin-Eosin stain for light microscopic evaluation. The results of this study were as follows: 1. Resorption : Loose collagen membrane group was resorbed most rapidly. Dense collagen membrane group and freeze-dried bovine dura mater group were rarely resorbed. 2. Inflammatory reactions : PLA/PLGA membrane group showed persistent and severe inflammatory reactions for 3 to 8 weeks. Moderate inflammatory reactions and the ectopic formation of calcified material were observed in dense collagen membrane group. Freeze-dried bovine dura mater group and loose collagen membrane group showed mild inflammatory reactions 3. In PLA/PLGA membrane group, multinucleated giant cells by foreign body reactions were observed. In conclusion, the resorption of freeze-dried bovine dura mater didn't happen for 3-6weeks, which showed the best bio-compatibility. Therefore, freeze-dried bovine dura mater was considered proper resorbable membrane for guided tissue regeneration.

• Journal of Periodontal and Implant Science
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• 제32권3호
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• pp.475-488
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• 2002

The purpose of this study is to evaluate histologically the resorption and tissue response of various resorbable collagen membranes used for guided tissue regeneration and guided bone regeneration, using a subcutaneous model on the dorsal surface of the rat. In this study, 10 Sprague-Dawley male rats (mean BW 150gm) were used and the commercially available materials included acellular dermal matrix allograft, porcine collagen membrane, freeze-dried bovine dura mater. Animals were sacrificed at 2,6 and 8 weeks after implantation of various resorbable collagen membranes. Specimens were prepared with Hematoxylin-Eosin stain for light microscopic evaluation. The results of this study were as follows: 1. Resorption : Inner portion of porcine collagen membrane was resorbed a lot at 6 weeks, but its function was being kept for infiltration of another tissues were not observed. Freeze-dried bovine dura mater and acellular dermal allograft were rarely resorbed and kept their structure of outer portion for 8 weeks. 2. Inflammatory reactions : Inflammatory reaction was so mild and foreign body reaction didn't happen in all of resorbable collagen membranes, which showed their biocompatibility. 3. In all of resorbable collagen membranes, multinuclcated giant cells by foreign body reactions were not observed. Barrier membranes have to maintain their function for 4-6 weeks in guided tissue regeneration and at least 8 weeks in guided bone regeneration. According to present study, we can find all of the resorbable collagen membranes kept their function and structure for 8 weeks and were rarely resorbed. Foreign body reaction didn't happen and inflammatory reaction was so mild histologically. Therefore, all of collagen membranes used in this experiment were considered proper resorbable membranes for guided tissue regeneration and guided bone regeneration.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.287-287
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• 2011

ITRS(international technology roadmap for semiconductors)에 따르면 MOS (metal-oxide-semiconductor)의 CD(critical dimension)가 45 nm node이하로 줄어들면서 poly-Si/SiO2를 대체할 수 있는 poly-Si/metal gate/high-k dielectric이 대두되고 있다. 일반적으로 metal gate를 식각시 정확한 CD를 형성시키기 위해서 plasma를 이용한 RIE(reactive ion etching)를 사용하고 있지만 PIDs(plasma induced damages)의 하나인 PICD(plasma induced charging damage)의 발생이 문제가 되고 있다. PICD의 원인으로 plasma의 non-uniform으로 locally imbalanced한 ion과 electron이 PICC(plasma induced charging current)를 gate oxide에 발생시켜 gate oxide의 interface에 trap을 형성시키므로 그 결과 소자 특성 저하가 보고되고 있다. 그러므로 본 연구에서는 이에 차세대 MOS의 metal gate의 식각공정에 HDP(high density plasma)의 ICP(inductively coupled plasma) source를 이용한 중성빔 시스템을 사용하여 PICD를 줄일 수 있는 새로운 식각 공정에 대한 연구를 하였다. 식각공정조건으로 gas는 HBr 12 sccm (80%)와 Cl2 3 sccm (20%)와 power는 300 w를 사용하였고 200 eV의 에너지로 식각공정시 TEM(transmission electron microscopy)으로 TiN의 anisotropic한 형상을 볼 수 있었고 100 eV 이하의 에너지로 식각공정시 하부층인 HfO2와 높은 etch selectivity로 etch stop을 시킬 수 있었다. 실제 공정을 MOS의 metal gate에 적용시켜 metal gate/high-k dielectric CMOSFETs의 NCSU(North Carolina State University) CVC model로 effective electric field electron mobility를 구한 결과 electorn mobility의 증가를 볼 수 있었고 또한 mos parameter인 transconductance (Gm)의 증가를 볼 수 있었다. 그 원인으로 CP(Charge pumping) 1MHz로 gate oxide의 inteface의 분석 결과 이러한 결과가 gate oxide의 interface trap양의 감소로 개선으로 기인함을 확인할 수 있었다.

• 혜화의학회지
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• 제17권2호
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• pp.51-68
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• 2008

The effect of combinational treatment of oral HTGMB and topical CSGMB ("H&C" hereinafter) on the changes of dermal inflammation index and immune system were studied using NC/Nga atopic dermatitis animal model. 1. Through naked eye examination, H&C ameliorated atopic dermatitis compared to the control group. Significant reduction of dermal inflammation index was observed after 12 weeks of treatment. 2. The H&C treated group showed 51% increase in the number of immune cells in DLN, and 59% increase in the number of immune cells is dorsal skin. 3. The H&C treated group showed decrease of 26%, 8%, 59% in CD19+, CD3+/CD69+, B220+/IgE+ cells in DLN respectively. On the other hand, CD3+, CD8+, CD4+ cells were increased by 8%, 31%, 12%, respectively. 4. The H&C treated group showed significant decrease of 38% and 47% in B220+/IgE+, CD11b+/Gr-1+ cells within dorsal skin respectively. Also, a decrease in CCR3+ cells by 21% was observed. 5. Significant decrease of the production of IL-4, IL-5, GM-CSF by 39%, 65%, 60% respectively, in spleen cells activated with CD3 and CD28 were observed in the H&C treated group. The results above strongly suggest significance of anti-atopic dermatitis effect of combinational treatment of oral HTGMB and topical CSGMB through immune modulation. Further applications in clinical use of the treatment are anticipated.

• Journal of Periodontal and Implant Science
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• 제32권1호
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• pp.113-127
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• 2002

The purpose of this study is to evaluate histologically the tissue response and resorption of various nonresorbable and resorbable suture materials used for periodontal surgery, using a subcutaneous model on the dorsal surface of the rat. In this study, 10 Sprague-Dawley male rats (mean BW 150gm) were used and the commercially available materials included polyglactin 910, pain gut, nylon, e-PTFE. Animals were sacrificed at 3 days, 1, 2 and 4 weeks after implantation of various nonresorbable and resorbable suture materials. Specimens were prepared with Hematoxylin-Eosin stain for light microscopic evaluation. The results of this study were as follows: 1. Resorption : The resorption of plain gut was showed at 1 week after implantation, was lost their structure and almost resorbed at 4 weeks. The resorption of polyglactin 910 was started at 2 weeks and slowly absorbed untill 4 weeks. 2. Tissue response : Plain gut showed persistent and severe inflammatory reactions from 3 days to 4 weeks. Polyglactin 910, e-PTFE and nylon showed mild inflammatory reactions. Suture material should be biocompatible and be able to be functioned until tissue tensile strength reaches maximum level. In this study, polyglactin 910, nylon and e-PTFE are considered to be proper suture materials for periodontal surgery.