• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.41-45
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• 2009

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzhemier's disease. Neuropathologically, PD is characterized by the selective loss of dopaminergic neurons. The neuronal toxicity of cytosolic excess dopamine (DA) has been described in many studies using several cell lines. In dopaminergic neurons, cytosolic excess DA is easily oxidized via monoamine oxidase (MAO)-B, tyrosinase or by auto-oxidation to produce neurotoxic metabolites such as DA quinone. So, in the present study, we induced cell death by treatment of DA ($600{\mu}M$) in human neuroblastoma SH-SY5Y cell which was treated samples before 24 hr, and cell viability was measured by fluorescence activated cell sorter (FACs) analysis. Of those tested, the extracts of Poria cocos (赤茯笭)(whole), Gastrodia elata (rhizomes), Eucommia ulmoides (炒)(barks), Syneilesis palmata (whole), Acorus gramineus (rhizomes), Ligustrum japonicum (leaves) showed neuroprotective effects in dose dependent manner.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.86.1-86.1
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• 2011

To improve the safety, the fuel cell operate inside a pressurized enclosure which contains inert gas so called protective gas. The protective gas not only prevents the mixture of hydrogen and oxygen, but also removes the water in the vessel with the condenser. This study presents the details of the flow optimization in order to reduce the humidity in the fuel cell housing. The protective gas flow in the fuel cell container is studied by Computational Fluid Dynamics(CFD) simulations. This study focuses on optimizing the geometry of an protective gas circulation system in fuel cell module to reduce the humidity in the vessel. CFD analysis was carried out for an existing model to understand the flow behavior through the fuel cell system. Based on existing model CFD results, geometrical changes like inlet placement, optimization of outlet size, modification of fuel cell module system are carried out, to improve the flow characteristics. The CFD analysis of the optimized model is again carried out and the results show good improvement in protective gas flow behavior.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.218-222
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• 2003

Even if using the standard field test which radiation of electric wave and measurement test equipment there are difficult thing that building test equipment. so, we can use the substitution test field. In this paper, for optimization analysis for homogeneous field structure of GTEM-CELL (Giga hertz Transverse Electro Magnetic Cell) that calculate electromagnetic field characteristic for variable of each structure and characteristic impedance inner conductor.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.448-456
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• 2021

Background Locoregional stem cell delivery is very important for increasing the efficiency of cell therapy. Amnisite BA (Amnisite) is a freeze-dried amniotic membrane harvested from bovine placenta. The objective of this study was to investigate the retention of cells of the stromal vascular fraction (SVF) on Amnisite and to determine the effects of cell-loaded Amnisite in a porcine radiation-induced chronic wound model. Methods Initially, experiments were conducted to find the most suitable hydration and incubation conditions for the attachment of SVF cells extracted from pig fat to Amnisite. Before seeding, SVFs were labeled with PKH67. The SVF cell-loaded Amnisite (group S), Amnisite only (group A), and polyurethane foam (group C) were applied to treat radiation-induced chronic wounds in a porcine model. Biopsy was performed at 10, 14, and 21 days post-operation for histological analysis. Results Retaining the SVF on Amnisite required 30 minutes for hydration and 1 hour for incubation. A PKH67 fluorescence study showed that Amnisite successfully delivered the SVF to the wounds. In histological analysis, group S showed increased re-epithelialization and revascularization with decreased inflammation at 10 days post-operation. Conclusions SVFs had acceptable adherence on hydrated Amnisite, with successful cell delivery to a radiation-induced chronic wound model.

• Journal of Hydrogen and New Energy
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• v.31 no.6
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• pp.530-545
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• 2020

This paper reviews and summarizes the fuel-cell-related studies those have been recently published in major Korean Citation Index journals, aiming at analyzing the research trend in fuel cell technologies. Six major journals are selected for the literature survey; 57 papers are chosen for the detailed analysis through a screening examination on the total 1,040 papers published during between 2018 and 2020. Papers are classified into six technical categories, such as i) electrode, ii) electrolyte, iii) bipolar plate and stack, iv) fuel cell system, v) balance of plant, and vi) diagnosis-related studies, and summarized by the experts in the relevant area. Through this paper, we provide a comprehensive review on the recent trends and progress in fuel-cell-related research work in Korea.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.6
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• pp.381-389
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• 2021

Most diagnosis approaches rely on historical failure data that might not be feasible in real operating conditions because the battery voltage and internal parameters are nonlinear according to various operating conditions, such as cell-to-cell configuration and initial condition. To overcome this issue, the estimator and the predictor require integrated approaches that consider comprehensive data, with the degradation process and measured data taken into account. In this paper, vector autoregressive models (VAR) with various parameters that affect overdischarge to the cell in the battery pack were constructed, and the cell-to-cell parameters were identified using an adaptive model to analyze the influence of failure prognosis. The theoretical analysis is validated using experimental results in terms of the feasibility and advantages of fault prognosis.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.52.1-52.11
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• 2020

Objectives: Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated. Materials and Methods: Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis. Results: The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions. Conclusions: The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.481-488
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• 2000

The demands for mobile communication service are growing rapidly. In heavily populated areas, cell split is unavoidable to increase the capacity of the cellular system. Cell splitting makes a cellular system to have mixed cell sizes. For cell planning, it is necessary to analyze the reverse link capacity of a CDMA cellular system with mixed cell sizes. In this paper, we propose a method to calculate the reverse link capacity of a CDMA cellular system with mixed cell sizes. When a macro cell is split into three micro cells, as an example, we calculate the reverse link capacities for the three micro cells and the neighboring macro cells. The results show that as the radius of a micro cell decreases, the reverse link capacity of the micro cell increases, while those of the neighboring macro cells decrease.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.1
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• pp.46-54
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• 2010

Ceramide induces cell death in a variety of cell types however, the underlying molecular mechanisms related to renal epithelial cells remain unclear. The present study was undertaken to determine the role of extracellular signal-regulated protein kinase (ERK) in ceramide-induced cell death in renal epithelial cells. An established renal proximal tubular cell line of opossum kidney (OK) cells was used for this research. Ceramide induced apoptotic cell death in these cells. Western blot analysis showed that ceramide induced activation of ERK. The ERK activation and cell death induced by ceramide were prevented by the ERK inhibitor PD98059. Ceramide caused cytochrome C release from mitochondria into the cytosol as well as activation of caspase-3. Both effects were prevented by PD98059. The ceramide-induced cell death was also prevented by a caspase inhibitor. These results suggest that ceramide induces cell death through an ERK-dependent mitochondrial apoptotic pathway in OK cells.

• Molecules and Cells
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• v.42 no.3
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• pp.189-199
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• 2019

Cell-to-cell variability in gene expression exists even in a homogeneous population of cells. Dissecting such cellular heterogeneity within a biological system is a prerequisite for understanding how a biological system is developed, homeostatically regulated, and responds to external perturbations. Single-cell RNA sequencing (scRNA-seq) allows the quantitative and unbiased characterization of cellular heterogeneity by providing genome-wide molecular profiles from tens of thousands of individual cells. A major question in analyzing scRNA-seq data is how to account for the observed cell-to-cell variability. In this review, we provide an overview of scRNA-seq protocols, computational approaches for dissecting cellular heterogeneity, and future directions of single-cell transcriptomic analysis.