• 한국공작기계학회논문집
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• 제12권6호
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• pp.92-96
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• 2003

Feul-Cell system consists of fuel reformer, stack and energy translator. Among these parts, stack is a core part which produces electricity directly. In order to set a stack module, fabrication of appropriate stack, design of water flow path in stack and control of coolant are needed. Especially, oater or air is used as a coolant to dissipate heat. The different temperature of each electric cell after cooling affects the performance of the stack. Therefore, it is necessary that the relationship between coolant hearing rate, width of stack, properties of stack, and the shape of water flow path must be understood. For the optimal design, the computational simulation by CFD-ACE has been conducted and the resulting database has been constructed.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1175-1180
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• 2013

A microfabricated electrochemical cell comprising PDMS-based microchannel and in-channel gold microelectrodes was fabricated as a sensitive and a miniature alternative to the conventional electroanalytical systems. A reproducible fabrication procedure enabled patterning of multiple microelectrodes integrated within a PDMS-based fluidic network. The active area of each electrode was $200{\mu}m{\times}200{\mu}m$ with a gap of $200{\mu}m$ between the electrodes which resulted in a higher signal to noise ratio. Also, the PDMS layer served the purpose of shielding the electrical interferences to the measurements. Analytes such as potassium ferrocyanide; amino acid: cysteine and nucleoside: guanosine were characterized using the fabricated cell. The microchip was comparable to bulk electrochemical systems and its applicability was also demonstrated with flow injection based rapid amperometric detection of DNA samples. The device so developed shall find use as a disposable electrochemical cell for rapid and sensitive analysis of electroactive species in various industrial and research applications.

• Journal of Information Display
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• 제2권4호
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• pp.46-51
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• 2001

Using ray-optics code incorporated with three-dimensional PDP cell simulation, we have analysed the energy flow in the PDP cell from the electric power input to the visible light output. Also, the visible light output profile and viewing angle distribution were obtained. We applied our code to the analysis of the barrier rib height effect on the visible light luminance and efficiency of the sustaining discharge. Although cells with higher barrier rib generate more VUV photons, less ratio of visible photons are emitted toward front panel due to the shadow effect. Thus, there exists optimal barrier rib height giving the highest visible luminance and efficiency. This kind of code can be a powerful tool in designing cell geometry.

• 한국정보기술학회 영문논문지
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• 제9권1호
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• pp.103-113
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• 2019

Motivation: Polymerized actin-based cytoskeletal structures are crucial in shape, dynamics, and resilience of a cell. For example, dynamical actin-containing ruffles are located at leading edges of cells and have a significant impact on cell motility. Other filamentous actin (F-actin) bundles, called stress fibers, are essential in cell attachment and detachment. For this reason, their mechanistic understanding provides crucial information to solve practical problems related to cell interactions with materials in tissue engineering. Detecting and counting actin-based structures in a cellular ensemble is a fundamental first step. In this research, we suggest a new method to characterize F-actin wrapping fibers from confocal fluorescence image stacks. As fluorescently labeled F-actin often envelope the fibers, we first propose to segment these fibers by diminishing an energy based on maximum flow and minimum cut algorithm. The actual actin is detected through the use of bilateral filtering followed by a thresholding step. Later, concave actin bundles are detected through a graph-based procedure that actually determines if the considered actin filament is enclosing the fiber.

• KSBB Journal
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• 제4권3호
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• pp.281-287
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• 1989

The experimental study reported herein was to investigate to separation characteristics of a tangential flow membrane in a continuous recycle situation. Physical and dynamic analyses are performed on the membrane system in order to relate relevant variables to the capacity of separation. The results of separation process may be summarized by a proposed equation:Sh=A(Re.Sc.dh/L)1/3. It was shown also by the analyses that effective separation of sugar and cell was attainable by means of tangential membranes, thereby enhancing ethanol productivity in fermentation with continuous cell and substrate recycle.

• Toxicological Research
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• 제21권1호
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• pp.77-85
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• 2005

Cadmium is an environmental pollutant exposed from contaminated foods or cigarette smoking and known to cause oxidative damage in organs. We investigated the cadmium-induced apoptosis and cell arrest in human breast cancer cells, MCF-7 cells and MDA-MB-231 cells. Obvious apoptotic cell death was shown in CdCl₂ 100 μM treatment for 12 hr, which were determined by DAPI staining and flow cytometric analysis. In cell cycle analysis, MCF-7 cells and MDA-MB-231 cells were arrested in S phase and G2/M phase respectively. These could be explained by the induction of cell cycle inhibitory protein, p21/sup Waf1/Cip1/ and p27/sup Kip1/, expression and reduction of cyclin/Cdk complexes in both cell lines. The decreased expression of cyclin A and Cdk2 in MCF-7 cells and cyclin B1 and Cdc2 in MDA-MB-231 cells were consistent with the flow cytometric observation. p-ERK expression was increased dose-dependent manner in both cell lines. It suggests that ERK MAPK pathway are involved in cadmium-induced cell cycle arrest and apoptosis. Moreover, cotreatment of zinc (100 μM, 12 hr) recovered the cadmium-induced cell arrest in both cells, which shows cadmium-induced oxidative stress mediates apoptosis and cell cycle arrest in human breast cancer cells.

• 동의생리병리학회지
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• 제16권4호
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• pp.693-700
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• 2002

SCRT (Sochungyong-tang) has been used for immune disease in human. The purpose of this study was effect of Helper T cell, major regulator of immune system. Spleen cell from 8 week BALB/c mice were cultured in SCRT containing medium without activation for 48 h. The MTS assay and flow cytometry revealed that SCRT treated Iympocyte were non-effect in percentage of CD4+ T cell. Subsequently CD4+ T cell were isolated and cultured in SCRT containing medium. SCRT were non-effective on CD4+ T cell without any involvement of APC. In order to evaluate the direct effect of SCRT on Helper T cell, CD4+ T cell isolated after 48 h of culture in SCRT containing medium and activated with and without anti-CD3/anti-CD28 activation for 48 h. A lower level of CD69 was observed in SCRT treated cells in flow cytometry analysis. Subsequently Using RT-PCR analysis the expression of mRNA for IL-2, INF-γ are upregulated and, IL-4 is downregulated in CD4 T cell. The result suggests that SCRT makes Th1 significantly increased and Th2 relatively inhibited. The results suggest that SCRT potentiate Th1 cell and decrease Th2 development at the same time, which is believed to be bemeficial for IgE-mediated responses.

• 한국발생생물학회지:발생과생식
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• 제2권1호
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• pp.1-8
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• 1998

본 연구에서는 자연세포사 (apoptosis)를 유발시키는 것으로 알려진 ceramide를 배양중인 생쥐 과립세포에 처리한 뒤 형광염색, in-situ 3'-end labeling(ISEL), 그리고 flow cytometry 기법을 이용하여, 자연세포사 및 세포주기에 미치는 ceramide의 영향을 조사하였다. Ceramide를 처리하지 않은 대조군에 비하여, ceramide를 처리한 실험군에서 세로의 생존율은 농도에 비레하여 유의하게 감소하였다. 또한 acridine orange에 의한 형광염색 결과, 자연세포사의 양상을 보이는 핵을 갖는 세포의 수가 ceramide의 농도가 증가함에 따라 현저하게 증가되었다. 또한 ISEL을 실시해 본 결과, 자연세포사가 ceramide의 처리농도가 증가됨에 따라 점차적으로 증가되었다. 한편, ceramide를 처리한 과립세포의 세포주기 분석을 위한 flow cytometry 결과도 자연세포사가 일어난 $A_{0}$기에 있는 세포들의 비율이 대조군에 비하여 농도 의존적으로 증가하였으며, $G_{0}$/$G_{1}$ 기에 있는 세포들이 비율은 현저하게 감소됨을 관찰할 수 있었다. 위의 결과로 보아 ceramide는 생쥐 과립세포의 $G_{0}$/$G_{1}$ 기에 특이저긍로 자\ulcorner하여 자연세포사를 유발하며, 난포의 폐쇄시 과립세포의 자연세포사를 유발할 것으로 사료된다.

• 대한임상검사과학회지
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• 제54권1호
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• pp.68-72
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• 2022

혈관면역모세포성 T세포 림프종(AITL)은 성숙 T follicular helper cells의 림프증식성 질환이다. 80세 여성의 골수에서 비정형 림프구가 관찰되었고 B세포에 대한 유세포검사에서 CD19+, CD20-, CD22- 및 lambda 경쇄 restriction과 같은 비정상 표현형이 관찰되었다. 처음에는 유세포검사에서 관찰된 비정상 B세포에 대해 B세포 림프종을 의심하였다. 그러나 환자는 골수를 침범한 AITL로 진단되었다. 유세포검사의 재분석에서 소수의 비정상 T세포 군집을 발견했다. 표면 lambda 경쇄 restriction은 비특이적 결합으로 생각되었다. EBV 양성 T세포 림프종 환자에서 형질세포와 유사한 면역표현형을 가진 B세포가 관찰될 수 있다. 이러한 비정상 B세포 혹은 형질세포의 증식이 기저에 존재하는 T세포 림프종을 가릴 수 있다. 정확한 진단을 위해서는 통합적인 접근이 필요할 것이다.

• 한국전산유체공학회지
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• 제8권2호
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• pp.33-41
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• 2003

A simplified simulation model is designed to investigate the vacuum-driven bonding of glass panels in the cell process for LCD manufacturing. The bonding process is modelled by the transient flow of a weakly-compressible fluid in a very thin channel between two horizontal glass panels. An order of magnitude scaling analysis is conducted based on the characteristic feature of the channel of which height is much smaller than the horizontal length scales. It is revealed that the flow in the channel is represented by a Poiseuille flow of a compressible fluid. A finite volume model has been constructed to acquire the numerical solution to the derived simplified equations. For a simple test problem of pressure-driven microchannel flow, an assessment is made of the accuracy and validity of the proposed model. The basic aspects of vacuum-driven bonding are examined numerically, and the applicability of the present simulation model is illustrated.