• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.371-383
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• 2014

The nematode Caenorhabditis elegans (C. elegans) offers a unique opportunity for biological and basic medical researches due to its genetic tractability and well-defined developmental lineage. It also provides an exceptional model for genetic, molecular, and cellular analysis of human disease-related genes. Recently, C. elegans has been used as an ideal model for the identification and functional analysis of drugs (or small-molecules) in vivo. In this review, we describe conserved oncogenic signaling pathways (Wnt, Notch, and Ras) and their potential roles in the development of cancer stem cells. During C. elegans germline development, these signaling pathways regulate multiple cellular processes such as germline stem cell niche specification, germline stem cell maintenance, and germ cell fate specification. Therefore, the aberrant regulations of these signaling pathways can cause either loss of germline stem cells or overproliferation of a specific cell type, resulting in sterility. This sterility phenotype allows us to identify drugs that can modulate the oncogenic signaling pathways directly or indirectly through a high-throughput screening. Current in vivo or in vitro screening methods are largely focused on the specific core signaling components. However, this phenotype-based screening will identify drugs that possibly target upstream or downstream of core signaling pathways as well as exclude toxic effects. Although phenotype-based drug screening is ideal, the identification of drug targets is a major challenge. We here introduce a new technique, called Drug Affinity Responsive Target Stability (DARTS). This innovative method is able to identify the target of the identified drug. Importantly, signaling pathways and their regulators in C. elegans are highly conserved in most vertebrates, including humans. Therefore, C. elegans will provide a great opportunity to identify therapeutic drugs and their targets, as well as to understand mechanisms underlying the formation of cancer.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.97-97
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• 2010

We demonstrate the hybrid polymer-quantum dot based multi-functional device (Organic bistable devices, Light-emitting diode, and Photovoltaic cell) with a single active-layer structure consisting of CdSe/ZnS semiconductor quantum-dots (QDs) dispersed in a poly N-vinylcarbazole (PVK) and 1,3,5-tirs- (N-phenylbenzimidazol-2-yl) benzene (TPBi) fabricated on indium-tin-oxide (ITO)/glass substrate by using a simple spin coating technique. The multi-functionality of the device as Organic bistable device (OBD), Light Emitting Diode (LED), and Photovoltaic cell can be successfully achieved by adding an electron transport layer (ETL) TPBi to OBD for attaining the functions of LED and Photovoltaic cell in which the lowest unoccupied molecular orbital (LUMO) level of TPBi is positioned at the energy level between the conduction band of CdSe/ZnS and LiF/Al electrode (band-gap engineering). Through transmission electron microscopy (TEM) study, the active layer of the device has a p-i-n structure of a consolidated core-shell structure in which semiconductor QDs are uniformly and isotropically adsorbed on the surface of a p-type polymer core and the n-type small molecular organic materials surround the semiconductor QDs.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.918-926
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• 2022

Proteins related to DNA replication have been proposed as cancer biomarkers and targets for anticancer agents. Among them, minichromosome maintenance (MCM) proteins, often overexpressed in various cancer cells, are recognized both as notable biomarkers for cancer diagnosis and as targets for cancer treatment. Here, we investigated the activity of cedrol, a single compound isolated from Juniperus chinensis, in reducing the expression of MCM proteins in human lung carcinoma A549 cells. Remarkably, cedrol also strongly inhibited the expression of all other MCM protein family members in A549 cells. Moreover, cedrol treatment reduced cell viability in A549 cells, accompanied by cell cycle arrest at the G1 phase, and enhanced apoptosis. Taken together, this study broadens our understanding of how cedrol executes its anticancer activity while demonstrating that cedrol has potential application in the treatment of human lung cancer as an inhibitor of MCM proteins.

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.88-92
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.58.1-58
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1209-1210
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• 2011

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.465-470
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• 2010

Korea government declared that "low carbon, green growth" through green technologies and clean energy to be the new national vision for the next 60 years(President's Liberation Day speech on Aug. 15, 2008). And succeeding "Green New Deal" plan involves nine core projects including energy saving, recycling, clean energy development. It is because hydrogen fuel cell vehicles, using electricity from chemical reaction of hydrogen and oxygen, let out water which is a by-product of such chemical reaction instead of emitting harmful particulate and gases such as NOX, SOX and CO2 that hydrogen fuel cell vehicles and its technology are drawing public attention as one of the sensible solutions in accomplishing "low carbon, green growth" agenda. Nevertheless There are many chances that let the people have a practical experience of hydrogen fuel cell vehicles. Sometimes new products, including hydrogen fuel cell vehicles, made by advanced technology can not penetrate through the market when it faces public skepticism that is stimulated from lack of knowledge and experience. That is the reason why not only cost benefit analyses and scientific risk assessments but also public acceptance studies toward hydrogen fuel cell vehicles have to be performed [Schulte, 2004]. This research address a need for comprehensive study on factors influencing public acceptance of hydrogen fuel cell car, specifically focusing on impacts of personal experience related to governmental science and technology policy toward public acceptance.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.5
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• pp.359-366
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• 2008

A two-dimensional thermal model of proton exchange membrane fuel cell with large active area is developed to investigate the performance of fuel cell with large active area over various thermal management conditions. The core sub-models of the two-dimensional thermal model are one-dimensional agglomerate structure electrochemical reaction model, one-dimensional water transport model, and a two-dimensional heat transfer model. Prior to carrying out the simulation, this study is contributed to set up the operating temperature of the fuel cell with large active area which is a maximum temperature inside the fuel cell considering durability of membrane electrolyte. The simulation results show that the operating temperature of the fuel cell and temperature distribution inside the fuel cell can affect significantly the total net power at extreme conditions. Results also show that the parasitic losses of balance of plant component should be precisely controlled to produce the maximum system power with minimum parasitic loss of thermal management system.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.154-165
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• 2021

This study aimed to investigate whether the antidiabetic drugs dipeptidyl peptidase 4 (DPP4) inhibitors such as evogliptin and sitagliptin affect the membrane DPP4 (mDPP4) enzymatic activity and immune function of T helper1 (Th1) cells in terms of cytokine expression and cell profiles. The mDPP4 enzymatic activity, cytokine expression, and cell profiles, including cell counts, cell viability, DNA synthesis, and apoptosis, were measured in pokeweed mitogen (PWM)-activated CD4+CD26+ H9 Th1 cells with or without the DPP4 inhibitors, evogliptin and sitagliptin. PWM treatment alone strongly stimulated the expression of mDPP4 and cytokines such as interleukin (IL)-2, IL-10, tumor necrosis factor-alpha, interferon-gamma, IL-13, and granulocyte-macrophage colony stimulating factor in the CD4+CD26+ H9 Th1 cells. Evogliptin or sitagliptin treatment potently inhibited mDPP4 activity in a dose-dependent manner but did not affect either the cytokine profile or cell viability in PWM-activated CD4+CD26+ H9 Th1 cells. These results suggest that, following immune stimulation, Th1 cell signaling pathways for cytokine expression function normally after treatment with evogliptin or sitagliptin, which efficiently inhibit mDPP4 enzymatic activity in Th1 cells.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.1
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• pp.40-46
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• 2017

We reviewed the electrical properties of SOFC anode manufactured using spherical Ni and nano YSZ powder. When core-shell is fabricated by using submicron Ni as core and nano-sized YSZ as shell for SOFC anode, the electrical conductivity of the $0.2{\mu}m$ Ni-YSZ core-shell was 3 times higher than that of $1.0{\mu}m$ NiO or $1.0{\mu}m$ Ni-YSZ. Hydrogen selectivity was similar at $800^{\circ}C$, but hydrogen selectivity and methane conversion rate under $750^{\circ}C$ was 10~25% higher, Power density was more than 2 times, ASR was about 1/3, when exposed to $H_2$ atmosphere at $750^{\circ}C$ for a long time, Ni particles did not have any growth or cut off conduction path.