• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2006년도 The 6th Intermational Symposium on Developmental Biotechnology
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• pp.47-48
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• 2006

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 춘계학술세미나 및 워크숍
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• pp.19-25
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• 2002

Researches on manipulation pluripotent stem cells derived from blastocysts or promordial germ cells (PGCs) have a great advantages for developing innovative technologies in various fields of life science including medicine, pharmaceutics, and biotechnology. Since the first isolation in the mouse embryos, stem cells or stem cell-like colonies have been continuously established in the mouse of different strains, cattle, pig, rabbit, and human. In the animal species, stem cell biology is important for developing transgenic technology including disease model animal and bioreactor production. ES cell can be isolated from the inner cell mass of blastocysts by either mechanical operation or immunosurgery. So, mass production of blastocyst is a prerequisite factor for successful undertaking ES cell manipulation. In the case of animal ES cell research, various protocol of gamete biotechnology can be applied for improving the efficiency of stem cell research. Somatic cell nuclear transfer technique can be applied to researches on animal ES cells, since it is powerful tool for producing clone embryos containing genes of interest. In this presentation, a brief review was made for explaining how somatic cell nuclear transfer technology could contribute to improving stem cell manipulation technology.

• 한국임상수의학회지
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• 제28권1호
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• pp.63-70
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• 2011

To consider the iliac fossa as the vascular anastomosis site of kidney transplantation for the short-term study of acute rejection in pigs. Twelve domestic pigs weighing 39~48 kg underwent heterotopic renal allgraft transplantation. The experimental animals were divided into 2 groups in terms of renal vascular anastomosis site; the external iliac artery and vein were used in iliac fossa model (n = 6), the abdominal aorta and the caudal vena cava inferior to the kidney were used in abdominal cavity model (n = 6). Renal function was evaluated by daily measurement of plasma creatinine and BUN concentrations. The experiments' health including postoperative complications was also assessed daily for 8 days after transplantation. After euthanazation gross and histopathologic analysis was performed. All six pigs in iliac fossa model developed neuropraxia and lameness of the ipsilateral pelvic limb. However, no necrosis was observed in any pigs. In the abdominal cavity model, durations of both the surgical operation and the vascular anastomosis were significantly longer than those in the iliac fossa model. Furthermore, ischemia injury of the transplanted kidney was increased in abdominal cavity model, which induced accelerated-acute immune response from day 4 after transplantation. Despite of pelvic limb complication, the iliac fossa model showed more advantages including not only less ischemia time related to easy vascular anastomosis, but also less immune response during the acute rejection period. The results indicate that the iliac fossa model may be appropriate to the study of acute rejection in porcine kidney transplantation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.951-955
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• 2001

The experimental comparison between bonded and unbonded types stem-cement interface was carried out on axisymmetric stem-cement-aluminum model of the femoral component of a total hip replacement. Human femur was modeled in non-tapered and tapered($7.5^{\circ}$) aluminum hollow cylinders to emulate the diaphyseal and metaphyseal segments of the femur. For unbonded type, we tested stems with three different taper angles($5^{\circ},\;7.5^{\circ},\;10^{\circ}$). In every case, the cement-aluminum interface was designed to endure 8MPa shear strength. (a measured value at cement-bone interface) We tested aluminum models under axial loading for both cases. As an experimental result, it was found that unbonded stem sustained more axial load as bonded stem in both cases, diaphyseal and metaphyseal models. The unbonded types failed in cement mantle under axial compressive load, while the bonded ones failed in shear at cement-aluminum interface. These results suggest that a polished stem will sustain much higher axial load than a roughened stem. And a polished stem will make more stable cement-bone interface that may promote better osteosythesis around the stem.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2009년도 특별 Symposium
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• pp.19-19
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• 2009

• Asian-Australasian Journal of Animal Sciences
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• 제24권1호
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• pp.37-44
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• 2011

Parthenogenetic embryonic stem (pES) cells could provide a valuable model for research into genomic imprinting and X-linked diseases. In this study, pES cell lines were established from oocytes of hybrid offspring of Kunming and 129/Sv mice, and pluripotency of pES cells was evaluated. The pES cells maintained in the undifferentiated state for more than 50 passages had normal karyotypes with XX sex chromosomes and exhibited high activities of alkaline phosphatase (AKP) and telomerase. Meanwhile, these cells expressed ES cell molecular markers SSEA-1, Oct-4, Nanog, and GDF3 but not SSEA-3 detected by immunohistochemistry and RT-PCR. The pES cells could be differentiated into various types of cells from three germ layers in vitro by analysis of embryoid bodies (EBs) with immunohistochemistry and RT-PCR, and in vivo by observation of pES cell-derived teratoma sections. Therefore, the established pES cell lines contained all features of mouse ES cells. This work provides a new strategy for isolating pES cells from Kunming mice, and the pES cell lines could be applied as the cell model in research into genomic imprinting and epigenetic regulation of Kunming mice.

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.61-70
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• 1996

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony inyowth and secondary long term fixation. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone stem interface. An accurate evaluation of interf'ace micromotion and stress/strain fields in the bone-implant system may be relevant for better understanding of clinical situations and improving THA design. Recently finite element method(FEM) was introduced in'orthopaedic research field due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional finite element model of proximal femur with $Multilock^{TM}$ stem of 1179 blick elements to analyse the micromotions and mechanical behaviors at the bone-stem inteface in early post-operative period for the load simulating single leg stance. The results indicates that the values of relative motion for this well fit stem were $150{\mu}m$ in maximum $82{\mu}m$ in minimum and the largest relative motion was developed in medial region of Proximal femur and in anterior-posterior direction. The motion in the proximal bone was much greater than in the distal bone and the stress pattern showed high stress concentration on the cortex near the tip of the stem. These findings indicate that the loading on the hip joint in the early postoperative situation before achieving bony ingrowth could produce large micromotion of $150{\mu}m$ and clinicaly non-cemented THA patient should not be allowed weight bearing strictly early in the postoperative period.

• 한국대기환경학회지
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• 제10권4호
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• pp.260-280
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• 1994

The STEM II(Sulfur Transport Eulerian Model II) was adapted to simulate transport/ chemistry/deposition of air Pollutants in the Eastern China and Korea. A 32 hour model simulation starting from 9 A.M. of 1989 November 25 during which no preciptation was observed. The Prevailing wind direction is from west to east. The MM4(Meteorological Model Version 4) was used to generate meteorological data such as temperatures, horizontal wind velocities and directions, humidities, air densities. Eddy diffusivities, dry deposition velocities and vertical wind velocities were calculated from the meteorological data. The initial condition and the emission data base were constructed from the measurements and governmental reports respectively. The model predictions of NO, NO$_2$, SO$_2$, $O_3$ at Seoul, Inchon and Pusan agree reasonably well with measurements. The model's predictability for the primary air pollutants is improved considerably as the time passes. Thus, it is concluded that the model's predictability can be significantly enhanced by reducing the uncertainties of initial conditions.

• Molecules and Cells
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• 제37권2호
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• pp.133-139
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• 2014

Idiopathic pulmonary fibrosis (IPF) is the most common and severe type of idiopathic interstitial pneumonias (IIP), and which is currently no method was developed to restore normal structure and function. There are several reports on therapeutic effects of adult stem cell transplantations in animal models of pulmonary fibrosis. However, little is known about how mesenchymal stem cell (MSC) can repair the IPF. In this study, we try to provide the evidence to show that transplanted mesenchymal stem cells directly replace fibrosis with normal lung cells using IPF model mice. As results, transplanted MSC successfully integrated and differentiated into type II lung cell which express surfactant protein. In the other hand, we examine the therapeutic effects of microvesicle treatment, which were released from mesenchymal stem cells. Though the therapeutic effects of MV treatment is less than that of MSC treatment, MV treat-ment meaningfully reduced the symptom of IPF, such as collagen deposition and inflammation. These data suggest that stem cell transplantation may be an effective strategy for the treatment of pulmonary fibrosis via replacement and cytoprotective effect of microvesicle released from MSCs.

• 한국정밀공학회지
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• 제24권2호
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• pp.140-148
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• 2007

THRA(Total Hip Replacement Arthroplasty) has been widely used for several decades as a viable treatment of otherwise-unsolved hip problems. In THRA surgery, cement mantle thickness is critical to long-term implant survival of femoral stem fixed with cement. Numerous studies reported thin or incomplete cement mantle causes osteolysis, loosening, and the failure of implant. To analyze the effect of femoral stem rotation on cement thickness, in this study, we select two most popular stems used in THRA. Using CAD models obtained from a 3D scanner, we measure the cement mantle thickness developed by the rotation of a femoral stem in the virtual space created by broaching. The study shows that as the femoral stem deviates from the target coordinates, the minimum thickness of cement decreases. Therefore, we recommend development of a new methodology for accurate insertion of a femoral stem along the broached space. Also, modification of the stem design robust to the unintentional movement of a femoral stem in the broached space, can alleviate the problem.