• BMB Reports
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• 제44권8호
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• pp.512-516
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• 2011

Establishment of immortalized human dermal papilla cells (DPCs) retaining the characteristics of DPCs would be a great help for hair researchers. We recently established a simian virus 40T (SV40T)-transformed human DP cell line (SV40TDPC). However, the cell line senesced around passage 25 and ceased proliferation. In this study, we introduced the human telomerase reverse transcriptase (hTERT) gene into SV40T-DPC and established an immortalized human DP cell line. The cell line, SV40T-hTERT-DPC, did not induce tumors when inoculated into nude mice. SV40T-hTERT-DPC maintained morphology of early passage DPCs, expressed markers of DPCs, and retained responses to Wnt/${\beta}$-catenin and bone morphogenic protein (BMP) signaling pathways known to be required for hair-inducing activity of DPCs. The data strongly suggest that SV40T-hTERT-DPC retains many characteristics of human DPCs in vivo without malignant transformation.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.81-88
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• 2015

We investigated factors affecting primary cultures of Pacific abalone Haliotis discus hannai ovary-dissociated cells to identify general aspects of their early-phase culture. Ninety-seven cell populations derived from 30 individuals were cultured in different media with varying compositions of medium supplements, and initial attachment, subculture, and survival for ${\geq}10$ weeks were assessed according to medium composition and individual. We also examined the time required for subculture and the rate of cell death according to both culturing period and passage number within 10 weeks. A lack of fetal bovine serum (FBS) and hemolymph significantly inhibited the growth of cultured cells, while we detected no significant effect of medium composition on initial cell attachment. Through data reallocation, with the omission of data from cell populations cultured in FBS-free and hemolymph-free media, we showed that growth inhibition was also affected by individual differences among the abalones used. During the culture, we observed four different types of cell morphology. Moreover, considerable time was required for subculture-18.4 and 19.5 days for first and second subcultures, respectively-and cell death did not occur within 30 days or for passage 0. Our results will provide valuable information for developing universal cell culturing guidelines in abalone species and suggest the feasibility of culturing abalone ovary-dissociated cells.

• 한국전산유체공학회지
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• 제14권1호
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• pp.9-17
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• 2009

In this study we investigated the characteristics of fluid flow and heat transfer within a coolant passage in the cylinder head assembly of an internal combustion engine by using a commercial CFD code, CFX The complex coolant passage of the cylinder head assembly was modelled by suitable choice of a grid system and careful attention was paid in the construction of meshes near the walls where significant cooling occurs. To treat the simultaneous heating and cooling of the combustion walls we invented a methodology allowing a heat source within the solid wall and the convective cooling at the interface between the solid and the fluid. We managed to reproduce the experimental results by adjusting parameters appropriately. We have found that high temperature was concentrated at the surface of the cylinder jacket. It turned out that the effect of oil cooling from the piston head was unexpectedly significant. On the other hand the effect of cooling from the ambient air is almost negligible. The CFD method proposed in this study is believed to be useful in the early stage of the design of the engine-cooling system.

• Clinical and Experimental Reproductive Medicine
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• 제36권4호
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• pp.311-319
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• 2009

목 적: 인간 배아줄기세포 (human embryonic stem cells; hESCs)는 미분화 상태로 무한 증식할 수 있는 자가 증식(self-renewal) 능력과 인체의 모든 세포로 분화할 수 있는 전분화능 (pluripotency)의 특징을 가진 세포로, 손상된 세포를 건강한 세포로 대체하고자 하는 세포치료 (cell therapy) 연구에 활용하기 위한 세포 공급원 (cell source)으로 제시되고 있다. 그러나 인간 배아줄기세포는 확립된 초기에 세포를 안정적으로 배양하고 유지하는 과정이 쉽지 않으며, 특히 동결보존되어 있던 세포를 해동한 후 배양할 때 자연 발생적 분화가 높기 때문에 세포주의 유지에 많은 어려움이 따른다. 본 연구에서는 동결보존되어 있던 초기 계대의 인간 배아줄기세포를 해동하여 다시 배양할 때 자연 발생적 분화 부분을 기계적 분리 방법으로 제거하여 미분화 상태의 세포를 보다 빠르게 확보하기 위한 효율적인 방법에 대해 알아보고자 하였다. 연구방법: 인간 배아줄기세포를 계대 배양한지 4일이 되는 날, 50% 이상의 자연 발생적 분화가 나타난 세포군에서 분화된 부분만을 절개용 유리 피펫 (drawn-out dissecting pasture pipette)을 사용하여 기계적인 방법으로 제거하였다. 이후 지속적으로 배양액을 교환해 주며 세포군의 제거된 부분을 7일째 되는 날까지 관찰하였다. 결 과: 기계적 분리 방법을 사용하여 인간 배아줄기세포의 자연 발생적인 분화 부분을 제거한 빈 공간에 미분화상태의 인간 배아줄기세포가 분열하여 채워지는 것을 관찰하였다. 또한, 이 실험 방법을 연속 두 번 적용하여 배양했을 때 미분화 세포로 회복되는 세포군의 비율이 조금 더 높아지는 것을 확인할 수 있었다. 결 론: 동결되어 있던 초기 계대 인간 배아줄기세포의 해동 후, 자연 발생적 분화에 의해 미분화 상태를 유지하는 세포의 수가 적어 계대를 유지 하기가 어려울 때 이와 같은 기계적 분리 방법을 사용하여 자연 발생적 분화 부분을 제거한 후 배양을 지속하는 것이 단기간 내에 미분화 상태를 유지하는 인간 배아줄기세포의 양적 확보를 위한 효율적인 방법이라고 사료된다.

• 정신신체의학
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• 제6권2호
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• pp.97-103
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• 1998

A dolescence can be defined as the period between pubescence and physical maturity, and the passage through adolescence(age of 12-19) forms a critical period. Major developmental tasks of adolescence are construction of an emancipated identity, realistic ambitions, and reasonable ideals, and the further development of sexual and social identities. In early adolescence one struggles to adjust psychologically to the spurt in growth and tensions filled with sexual and aggressive impulses. There are reshuffling of peer groups due to differing rates of maturation, early adolescence crushes, sublimation of sexuality, and the resurgence of oedipal feelings. One reaches so-called period of formal operations in cognitive development. In mid-adolescence one struggles to overcome family attachments and controls, and it is a time marked by revolt and conformity. One has to overcome sexual repression while caught in reactivation of oedipal attachment. Peer groups gains in importance, and the peer group changes into a youth group that carries the youth culture. Late adolescence is a period of achieving an ego identity and capacities for intimacy. One has to prevent premature closure : Identity foreclosure limits both opportunity and the ability to guide one's own life. Gradually adolescent begins to have a loss self-centered and narcissistic orientation to one's sexual and affectional needs, and becomes involved in love relationship.

• 한국대기환경학회지
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• 제7권3호
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• pp.197-202
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• 1991

It is observed that the outbreak of dust storms (yellow sand) from Northern China and Mongolia occurs a few times in April 1988 and 1990. It is found that a dust storm initiated with strong gusty winds after the passage of a cold front, particularly after defrost of the ground surface of a source region in the early spring. According to meteorological chart, satellite images and trajectory analyses, dust clouds invaded Korea in April 1988 and 1990 were landing in the sink area after 2 $\sim$ 4 days travelling for 2,000 $\sim$ 3,000 km from a source region. It was also observed that in the west coast total suspended particulated (TSP) were 100 $\sim$ 200 $\mug m^{-3}$ and sulphates $(SO_4=)$ were 3 $\sim$ 10 $\mug m^{-3}$. These values clearly exceed the concentrations of a background level measured in the Arctic and Atlantic Ocean. Trajectory analyses and meteorological analyses suggest that the high values occurred with prevailing westerly flows coming from anthropogenic sources in China. High concentrations of air pollutants occurred in the backside of an anticyclone and in the area "col".col".uot;.

• 아동학회지
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• 제27권2호
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• pp.71-84
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• 2006

This study investigated the relationship between types of attachment and social adaptation of kindergarten children. Subjects were 108 3-year-old children, their mothers, and their teachers. Results showed that children securely attached to both mother and teacher adapted better than children who were insecurely attached to both mother and teacher. Children who were securely attached to mother but insecurely attached to teacher, and children who were insecurely attached to mother but securely attached to teacher adapted better than children who were insecurely attached to both mother and teacher. This study suggests that the quality of child-mother or child-teacher attachment affects children's social adaptation with the passage of time in kindergarten.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1945-1949
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• 2006

A storm-induced coastal inundation model (SICIM) is presented to simulate the flood event during typhoon passage that often results in significant rise in sea-level heights especially in the upstream region of the basin. The SICIM is a GIS-based distributed hydrodynamic model, both storm surge and storm water inundations are taken into account. The spatial and temporal distribution of the storm water level and flux are calculated. The model was applied to Jeju Island since it has an isolated watershed that is easy to handle as a first step of model application. Another reason is that it is surrounded by coastal area exposed to storm surge inundation. The model is still advancing and will be the framework of a predictive early inundation warning system.

• 대한정형외과스포츠의학회지
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• 제2권1호
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• pp.15-19
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• 2003

Although the number of anterior cruciate ligament reconstruction is increasing, complications after primary ACL reconstruction are more difficult to determine. Intraoperative and postoperative complications can lead to ultimate failure of a primary reconstructive procedure. Therefore, surgical success in ACL reconstruction requires detailed knowledge and technical advancements about ACL reconstruction. Preoperatively surgeon must pay attention to selection of grafts and methods of fixation, and intraoperatively, attention to the harvest of graft, passage of graft, intraarticuar placement of the graft, notchplasty, proper tensioning of the graft, and others. Postoperative complications must be detected early, including infection, abnormal healing responses, arthrofibrosis, graft rejection, and reflex sympathetic dystrophy. Careful patient selection, appropriate surgical timing, careful surgical technique, and supervised preoperative and postoperative rehabilitation can minimize postoperative complications.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.158-158
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• 2001

Bioflavonoids have been regarded as therapeutic agents for a wide range of disease including cancer. The increase of matrix metalloproteinases expression is a key event in several pathological conditions, e.g., dermal photocarcinogenesis, tumor initiation, invasion and metastasis. In this study, we investigated effects of quercetin, a major bioflavonoid in human diet, on matrix metalloproteinase (MMR)-1, MMP-2, MMP-3, MMP-9 mRNA expression during cellular aging in cultured human foreskin fibroblast. (omitted)