• 대한기계학회논문집A
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• 제35권11호
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• pp.1355-1360
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• 2011

흡착형 세포의 이동에 있어 세포와 바닥면간의 상호작용은 매우 중요한 역할을 한다. 본 논문은 주화성에 의한 흡착형 세포의 이동에 있어 세포와 바닥면과의 상호작용에 따른 영향을 보이기 위해 확산계면모델을 바탕으로 한 3 차원의 입체 모델을 제안한다. 세포와 바닥면간의 영향을 표현하기 위해 세포 주위 물질과의 관계를 고려한 경계에너지를 고려하였다. 본 연구에서 적용한 확산계면모델은 경계에너지, 주화성, 확산성을 모두 고려한 다중 메커니즘 모델로서 흡착형 세포이동의 역학적 특성을 정확히 예측하는데 있어 높은 신뢰성을 보일 것이라 기대된다.

• 대한금속재료학회지
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• 제47권11호
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• pp.699-706
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• 2009

Deformation behavior of pure aluminum during equal channel angular pressing (ECAP) was simulated using a three-dimensional version of the finite element method in conjunction with a constitutive model based on the dislocation density and cell evolution. The three-dimensional finite element analyses for the prediction of microstructural features, such as the variation of the dislocation density and the cell size with the number of ECAP, are reported. The calculated stress and strain and their distributions are also investigated for the route Bc ECAP processed pure aluminum. The results of finite element analyses are found to be in good agreement with experimental results for the dislocation cell size. Due to the accumulation of strain throughout the workpiece and an overall trend to saturation in cell size, a decrease of the difference in cell size with the number of passes (1~4) was predicted.

• Journal of Chest Surgery
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• 제30권6호
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• pp.566-572
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• 1997

유전자 치료등 폐암에 대한 새로운 치료법의 개발및 그 효능의 검증에 있어 적절한 동물 모델이 없음은 큰 제 한점중의 하나이다. 특히 종양의 생물학적 특성이나 치료에의 효과등이 장기자체의 환경에 크게 영향 을 받는다는 사실은, 인체에서의 폐암의 특성을 가지며 폐에 정 위적으로 발생하는 폐암의 동물모델의 개발 을 시급하게 한다. 저자등은 Nude rat을 대상 동물로 하여, 개흉하에 종양세포 부유액을 원하는 폐말단 부위에 직접 주입함으로 폐에 정 위적으로 폐암의 발달을 유도하였으며 이를 이용하여 발생된 비소세포 폐암의 병태를 연구하였다. 종양은 실험 대상 등물에서 모두 발생하였으며 이용한 두 가지 종류의 세포주(NCI-H46O과 NCI-H1299)에서 모두 효과적으로 발생하였다. 발생된 폐종양은 시간 경과에 따라 주위 조직으로의 침윤과 종격동 전이의 양상를 보였다. 종양 숙주 동물의 평균 수명은 약 5주 정도였다. 저자등이 개발한 비소세포폐암의 동물 모델은 기관지를 통한 종양 세포 주입법에 의한 폐암 모델에 비해 국소적으로 진행된 폐암을 원하는 부위에 정확히 만들 수 있음은 물론 외과적 처치를 비롯한 국소적 치료 방법의 개발이나 ?과의 검증에 두루 이용되기에 적절하다고 사료된다.

• 약학회지
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• 제39권5호
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• pp.541-547
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• 1995

In order to investigate the usability of PALMIWON as antidiabetic immuno-modulating prescription for Insulin-dependent diabetes, we studies the effects of PALMIWON on immune cell and ${\beta}-cell$. U937 was used as the model of immune cell and RINm5F as the model of ${\beta}-cell$. The effects of PALMIWON was measured by cell viability in terms of MIT assay. As a result, PALMIWON and the compositional drugs showed the different effects m immune cell and ${\beta}-cell$. Cell viability of U937 was significantly decreased wheras that of RINm5F was no significantly difference between drug treated group and control, or significantly less reduction compared with U937. It implies that PALMIWON is useful as immunotherapeutic agents in the prevention and therapy of type 1 diabetes.

• 신재생에너지
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• 제3권3호
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• pp.14-19
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• 2007

A flow channel model of a bipolar plate with varying cross-sectional area was newly designed for improving performance and efficiency of a PEM fuel cell stack. As a result, the varying cross-sectional area model showed poor uniformity in velocity distribution, however, maximum velocity in the flow path is about 30% faster than that of the uniform cross-sectional area model. The proposed varying cross-sectional area model is expected to diffuse operating fluids more easily into diffusion layer because it has relatively higher values in pressure distribution compared with other flow channel models. It is expected that the implementation of the varying cross-sectional area model can reduce not only the mass transport loss but also the activation loss in a PEM fuel cell, and open circuit voltage of a fuel cell can thus be increased slightly.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.554-559
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• 1998

Equalizing the state of charge of cell that affects the charge/discharge quality and efficiency of the battery through the charge/discharge characteristic experiments of battery source, we develope the high efficiency charge/discharge system which would be used in serial HEV with the constant engine-generator output. For this, establishes the electrical model of Ni-MH battery appropriate to the high efficiency charge/discharge conditions. There is no model of Ni-MH cell, so we used Ni-Cd model and obtain the Ni-MH model through the experiment. A reason that each cell has the same charge/discharge property for applying the cell model to serial/parallel connected battery source extensively is needed. Therefore, in this paper, propose the Ni-MH charger/discharger has the equalization charging function and selectable cut-off function.

• 대한기계학회논문집B
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• 제40권12호
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• pp.761-768
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• 2016

분리막을 이용한 탄화수소계 가스의 종 분리는 화학적 방법에 비해 공정 구성이 용이하고, 유지 보수가 쉬우며 또 경제성이 우수하다. 분리막 기술의 발전과 함께 다양한 응용이 가능하지만, 이를 위한 체계적인 공정 연구를 위한 해석 방법은 다양하지 않다. 본 연구에서는 상용 프로그램에서 제공하는 유저 루틴을 이용해 분리막의 공정 해석을 하기 위한 분리막 물질 전달 모델을 개발하였다. 모델 개발에서는 집중용량법, 다중 셀 기법, 그리고 차분형 모델링 기법을 비교하여 각각의 특징을 분석하였으며, 확장성과 정밀도가 우수한 차분형 모델링 기법을 최종 모델로 선정하였다. 선정모델을 이용해 분리막의 가스 투과율에 영향을 주는 인자인 투과율, 투과면적, 양단 압력차, 투과 유량 등에 대한 기초 해석을 수행하였다. 이를 통해 압력비가 높아지게 되면 투과율은 점진적으로 향상되지만, 실제 선택도는 압력비 상승에 대해 최적점이 존재함을 알 수 있으며, 투과율도 최적점이 존재하였다.

• 대한기계학회논문집A
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• 제33권1호
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• pp.56-63
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• 2009

Cell migration is one of the essential mechanisms responsible for complex biological processes. Intensive researches have begun to elucidate the mechanisms and search intriguing conditions for efficient control of cell migration. One general mechanism that is widely applicable for cells including Escherichia coli, amoebae and endothelial cell is chemotaxis. The single cell study for bacterial chemotaxis has an advantage over studies with the population of cells in providing a clearer observation of cell migration, which leads to more accurate assessments of chemotaxis. In this paper, we propose a three-dimensional model considering a single bacterium to study its chemotaxis. The semi-implicit Fourier spectral method is applied for high efficiency and numerical stability. The simulation results reveal rich dynamics of cell migration and provide quantitative assessments of bacterial chemotaxis with various chemoattractant gradient fields.

• BMB Reports
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• 제55권5호
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• pp.205-212
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• 2022

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic disorder characterized by suprapubic pain and urinary symptoms such as urgency, nocturia, and frequency. The prevalence of IC/BPS is increasing as diagnostic criteria become more comprehensive. Conventional pharmacotherapy against IC/BPS has shown suboptimal effects, and consequently, patients with end-stage IC/BPS are subjected to surgery. The novel treatment strategies should have two main functions, anti-inflammatory action and the regeneration of glycosaminoglycan and urothelium layers. Stem cell therapy has been shown to have dual functions. Mesenchymal stem cells (MSCs) are a promising therapeutic option for IC/BPS, but they come with several shortcomings, such as immune activation and tumorigenicity. MSC-derived extracellular vesicles (MSC-EVs) hold numerous therapeutic cargos and are thus a viable cell-free therapeutic option. In this review, we provide a brief overview of IC/BPS pathophysiology and limitations of the MSC-based therapies. Then we provide a detailed explanation and discussion of therapeutic applications of EVs in IC/BPS as well as the possible mechanisms. We believe our review will give an insight into the strengths and drawbacks of EV-mediated IC/BPS therapy and will provide a basis for further development.

• 동의생리병리학회지
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• 제38권1호
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• pp.16-21
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• 2024

Haepyoijin-tang and its main components have been used for phlegm, cough and dyspnea. Using a respiratory inflammation model, we intend to reveal the anti-inflammatory effect and pharmacological mechanism of Haepyoijin-tang. We induced the respiratory inflammation model by Aspergillus oryzae protease and ovalbumin administration. Female Balb/c mice (8 weeks old) were classified into four groups as follows: saline control group, aspergillus oryzae protease and ovalbumin induced respiratory inflammation group (vehicle), inflammation with Haepyoijin-tang (200 mg/kg) administration group, inflammation with dexamethasone (5 mg/kg) administration group (n=7). To identify the anti-inflammatory effects of Haepyoijin-tang water extracts, we measured the inflammatory cell number in bronchoalveolar lavage fluid (BALF) and total live lung cell number. In addition, we checked eosinophil ratio and number in BALF. And Interleukin (IL)-5 level was also measured in lung cell culture supernatant. To confirm the mechanism of anti-inflammatory effects, we analyzed the activated helper T cell (CD4⁺CD25⁺ cell) and Th2 cell (CD4⁺GATA3⁺ cell) ratio and number in lung by using flow cytometry. Finally, we attempted to confirm the immune mechanism by measuring the ratio and number of regulatory T cells (CD4⁺Foxp3⁺ cell). Haepyoijin-tang extracts treatment diminished inflammatory cell, especially, eosinophil number in BALF and total live lung cell number. Moreover, IL-5 level was reduced in Haepyoijin-tang treated group. Surprisingly, Haepyoijin-tang extracts administration not only decreased the activated helper T cell but also Th2 cell population in lung. Additionally, regulatory T cell population was increased in Haepyoijin-tang administration group. Our findings proved that Haepyoijin-tang extract have anti-inflammatory efficacy by suppressing Th2 cell activation and promoting regulatory T cell population.