• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.2
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• pp.150-156
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• 2022

This study proposes a design method of fuel cell DC/DC converter using in 5-ton forklift. For efficient hydrogen usage, targeted fuel cell system recirculates discarded hydrogen after fuel cell reaction. Recirculating hydrogen contains much impurities that reduces output power, increasing pressure that can damage the internal fuel cell reaction system. The proposed DC/DC converter effectively converts fuel cell power considering the voltage drop rate to reflect the recirculating hydrogen. Then, frequency control method is used to regulate the current ripple amount for battery and fuel cell hybrid configuration. Proposed power converter system design and control methods are verified in a practical fuel cell system that implements recirculating hydrogen.

• Molecules and Cells
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• v.46 no.2
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• pp.74-85
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• 2023

Single-cell research has provided a breakthrough in biology to understand heterogeneous cell groups, such as tissues and organs, in development and disease. Molecular barcoding and subsequent sequencing technology insert a single-cell barcode into isolated single cells, allowing separation cell by cell. Given that multimodal information from a cell defines precise cellular states, recent technical advances in methods focus on simultaneously extracting multimodal data recorded in different biological materials (DNA, RNA, protein, etc.). This review summarizes recently developed single-cell multiomics approaches regarding genome, epigenome, and protein profiles with the transcriptome. In particular, we focus on how to anchor or tag molecules from a cell, improve throughputs with sample multiplexing, and record lineages, and we further discuss the future developments of the technology.

• IMMUNE NETWORK
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• v.16 no.1
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• pp.1-12
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• 2016

Th2 cell immunity is required for host defense against helminths, but it is detrimental in allergic diseases in humans. Unlike Th1 cell and Th17 cell subsets, the mechanism by which dendritic cells modulate Th2 cell responses has been obscure, in part because of the inability of dendritic cells to provide IL-4, which is indispensable for Th2 cell lineage commitment. In this regard, immune cells other than dendritic cells, such as basophils and innate lymphoid cells, have been suggested as Th2 cell inducers. More recently, multiple independent researchers have shown that specialized subsets of dendritic cells mediate Th2 cell responses. This review will discuss the current understanding related to the regulation of Th2 cell responses by dendritic cells and other immune cells.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.424-431
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• 2024

Among the therapeutic strategies in cancer immunotherapy-such as immune-modulating antibodies, cancer vaccines, or adoptive T cell transfer-T cells have been an attractive target due to their cytotoxicity toward tumor cells and the tumor antigen-specific binding of their receptors. Leveraging the unique properties of T cells, chimeric antigen receptor-T cells and T cell receptor (TCR)-T cells were developed through genetic modification of their receptors, enhancing the specificity and effectiveness of T cell therapy. Adoptive cell transfer of chimeric antigen receptor-T cells has been successful for the treatment of hematological malignancies. To expand T cell therapy to solid tumors, T cells are modified to express defined TCR targeting tumor associated antigen, which is called TCR-T therapy. This review discusses anti-tumor T cell therapies, with a focus on engineered TCR-T cell therapy. We outline the characteristics of TCR-T cell therapy and its clinical application to non-hematological malignancies.

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.104.1-104.1
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• 2006

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.564-570
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• 2005

In the present study, the protective effects of Bcl-2 over-expression in a suspension culture (without any adaptation) and spent medium (low nutrient and high toxic metabolite conditions) were investigated. In the suspension culture without prior adaptation, the viability of the control cell line fall to 0% by day 7, whereas the Bcl-2 cell line had a viability of 65%. The difference in the viability and viable cell density between the Bcl-2 and control cell lines was more apparent in the suspension culture than the static culture, and became even more apparent on day 6. Fluorescence microscopic counting revealed that the major mechanism of cell death in the control cell line in both the static and suspension cultures was apoptosis. For the Bcl-2 cell lines, necrosis was the major mode of cell death in the static culture, but apoptosis became equally important in the suspension culture. When the NS0 6A1 cell line was cultured in spent medium taken from a 14 day batch culture, the control cell line almost completely lost its viability by day 5, whereas, the Bcl-2 still had a viability of 73%. The viable cell density and viability of the Bcl-2 cell line cultivated in fresh medium were 2.2 and 2.7 fold higher, respectively, than those of the control cultures. However, the viable cell density and viability of the Bcl-2 cultivated in the spent medium were 8.7 and 7.8 fold higher, respectively, than those of the control cultures. Most of the dead cells in the control cell line were apoptotic; whereas, the major cell death mechanisms in the Bcl-2 cell line were necrotic.

• Molecules and Cells
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• v.28 no.6
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• pp.521-527
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• 2009

Previously, we have reported tissue- and stage-specific expression of miR-372 in human embryonic stem cells and so far, not many reports speculate the function of this microRNA (miRNA). In this study, we screened various human cancer cell lines including gastric cancer cell lines and found first time that miR-372 is expressed only in AGS human gastric adenocarcinoma cell line. Inhibition of miR-372 using antisense miR-372 oligonucleotide (AS-miR-372) suppressed proliferation, arrested the cell cycle at G2/M phase, and increased apoptosis of AGS cells. Furthermore, AS-miR-372 treatment increased expression of LATS2, while over-expression of miR-372 decreased luciferase reporter activity driven by the 3' untranslated region (3' UTR) of LATS2 mRNA. Over-expression of LATS2 induced changes in AGS cells similar to those in AGS cells treated with AS-miR-372. Taken together, these findings demonstrate an oncogenic role for miR-372 in controlling cell growth, cell cycle, and apoptosis through down-regulation of a tumor suppressor gene, LATS2.

• Journal of Physiology & Pathology in Korean Medicine
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• v.38 no.1
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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.

• 대한생식의학회:학술대회논문집
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• 2007.11a
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• pp.118.1-118.1
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• 2007

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.320-325
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• 2005

Power of fuel cell tram is supplied by only fuel cell system or hybrid system of fuel cell and battery/super capacity. Fuel cell is operated by hydrogen, which is fed directly from hydrogen tank or by reforming gasoline or methanol into hydrogen. Power system is preferred with hybrid of fuel cell and battery/super capacity since it improves total energy efficiency through interaction of hybrid components and restores energy regenerated by braking. Also, power supply system by fuel cell hybrid should be designed to output optimum energy efficiency depending on driving mode of fuel cell tram.