• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.853-857
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• 2001

The effect of silkworm hemolymph on the inhibition of baculovirus-induced insect cell apoptosis was quantitatively investigated using a flow cytometric analysis. Spodoptera frugiperda (Sf9) cell and Autographa californica nuclear polyhedrous virus (AcNPV) were used as a model for insect cell and baculovirus in this study, respectively. Compared with a mammalian cell cycle, the fraction of G1 cells was relatively small in the Sf9 cell cycle. Silkworm hemolymph did not affect the Sf9 cell-cycle distribution before the baculovirus infection. However, the fraction of cells which are not in the sub-G1 phase remained at a high level for 3 days after the infection in the medium without silkworm hemolymph, while it remained at a high level for 7 days after the infection in the medium supplemented with silkworm hemolymph. The fractions of apoptotic cells in the sub-G1 phase were $4.7\%$, and 4 days after infection, $22.7\%$, in the media with and without silkworm hemolymph, respectively.

• Journal of Breast Disease
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• v.6 no.2
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• pp.39-45
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• 2018

Purpose: Dieckol, a phlorotannin compound isolated from Ecklonia cava, has been reported to have antioxidant, antiviral, anti-inflammatory, and anticancer properties. The purpose of this study was to investigate its anticancer effects on human breast cancer cell lines. Methods: In this study, the viability of two human breast cancer cell lines SK-BR-3 and MCF-7 was investigated after dieckol treatment using a WST-1 assay. Apoptosis and cell cycle distribution were assayed via Annexin V-fluorescein isothiocyanate and propidium iodide staining followed by flow cytometric analysis. Immunoblotting analysis was also performed using Bax/Bcl-2 to determine whether the dieckol-induced apoptosis was mediated by the intrinsic apoptotic pathway. Results: In a dose dependent manner, dieckol reduced the number of viable cells and increased the number of apoptotic cells. The effect of dieckol on the cell cycle distribution was analyzed using flow cytometry. Dieckol treatment significantly increased the percentage of MCF-7 and SK-BR-3 in the G2/M phase. Immunoblot analysis revealed that 24 hours of dieckol exposure increased the Bax/Bcl-2 ratio. Conclusion: Dieckol induced cytotoxicity in MCF-7 and SK-BR-3 human breast cancer cells inducing apoptosis and cell cycle arrest. Therefore, it is suggested that dieckol may be a potential therapeutic agent for breast cancer.

• Current Photovoltaic Research
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• v.8 no.3
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• pp.94-101
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• 2020

This study was trying to focus on achieving high efficiency of multi junction solar cell with thin film silicon solar cells. The proposed thin film Si-Ge/c-Si tandem junction solar cell concept with a combination of low-cost thin-film silicon solar cell technology and high-efficiency c-Si cells in a monolithically stacked configuration. The tandem junction solar cells using amorphous silicon germanium (a-SiGe:H) as an absorption layer of upper sub-cell were simulated through ASA (Advanced Semiconductor Analysis) simulator for acquiring the optimum structure. Graded Ge composition - effect of E_g profiling and inserted buffer layer between absorption layer and doped layer showed the improved current density (J_sc) and conversion efficiency (η). 13.11% conversion efficiency of the tandem junction solar cell was observed, which is a result of showing the possibility of thin film Si-Ge/c-Si tandem junction solar cell.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1664-1669
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• 2004

Design analysis of the solid oxide fuel cell and gas turbine combined power system is performed considering different methods for preheating cell inlet air. The purpose of air preheating is to keep the temperature difference between cell inlet and outlet within a practical design range. Three different methods are considered such as a burner in front of the cell, a preheater in front of the cell and recirculation of the cathode exit gas. Analyses are carried out for two maximum cell temperature differences. The greater temperature difference ensures higher efficiency. The cathode exit gas recirculation exhibits better performance than other methods.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.4
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• pp.283-290
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• 2009

This study focuses on the performance characteristics of polymer electrolyte membrane fuel cell (PEMFC) using the AC impedance technique. The experiment was carried out to investigate the optimal operating conditions of PEMFC such as cell temperature, flow rate, humidified temperature and back-pressure. The fuel cell performance was analyzed by DC electronic-loader with constant voltage mode and expressed by voltage-current density. Additionally, AC impedance was measured to analysis of ohmic and activation loss and expressed by Nyquist plot. The results showed that the cell performance increased with increase of cell temperature, air flow rate, humidified temperature and backpressure. Also, the activation loss decreased as the increase of cell temperature, air flow rate, humidified temperature and backpressure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.421-428
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• 2009

Inter-cell coordination has been an emerging issue for mitigating inter-cell interference in broadband wireless access networks such as IEEE802.16 and 3GPP LTE (Long Term Evolution). This paper proposes uplink/downlink hybrid inter-cell coordination patterns for a TDD (Time Division Duplex)/MC-CDMA (Multi-Carrier Code Division Multiple Access) system. For the performance analysis, closed forms of inter-cell interferences are derived when uplink and downlink transmissions coexist over a multi-cell environment. In the analysis, we find an optimal ratio of downlink transmit powers of BSs (Base Stations) based on the target outage probability and the performance according to ratios of uplink/downlink transmit powers of MSs (Mobile Stations)/BSs is explored. Our numerical results show that interference mitigation utilizing the characteristics of the uplink and downlink power ratio is very effective in improving system performance in terms of QoS.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.1
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• pp.87-101
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• 2013

The purpose of this study was to analyze differences in psychological characteristics according to cell phone dependency and use purpose in cell phone users of adolescences. Psychological characteristics of adolescents were consisted of attention aggression, somatic symptoms, social withdrawal, depression variables. The subjects were 2,158 cell phone owned second graders of middle school. A data of the Korean Child-Youth Panel Survey(KCYPS) was employed for the this study. Dependency and use purpose of cell phone were classified by cluster analysis into four groups with similar characteristics : 'high dependency-multipurpose', 'low dependency-social', 'low dependency-unsocial' 'middle dependency-peer interaction' groups. Major findings were that: the group differences in psychological characteristics were statistically significant. The 'low dependency-social' group showed highest on adjustments, and the other groups were maladaptive. Finally, implications for future research were discussed.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.345-351
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• 2003

Heptaplatin, cis-Malonato[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane]platinum(II), is a novel platinum-based antitumor agent with clinical potential against human stomach cancer and the 3rd generation of the cisplatin. This study was performed to study how cisplain, heptaplatin and sunpla which is a mixture of heptaplatin and mannitol (w: w=l : 2) affect cell viability of SK-MEL-28 human melanoma cell line. Heptaplatin ($IC_{50}$/; 95.35 $\mu$M) and sunpla ($IC_{50}$/; 10.95 11M) were less effect than cisplatin (IC $_{50}$; 10.92 $\mu$M) on the SK-MEL-28 cells. By cell cycle analysis using flow cytometry, it was identified that the cells were arrested at G2/M phase by cisplatin, heptaplatin and sunpla, and percentage of cell death group was increased according to increasing of time and concentration. These results suggest that cisplatin, heptaplatin and sunpla are a novel anticancer agent against human melanoma cell.l.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.3
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• pp.25-40
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• 2006

Purpose : This study was undertaken to evaluate the inhibitory effects of Arisaematis rhizoma on the cell proliferation in HeLa cells. Methods : The cultured cell after treatment in the different duration in 24, 48, 72 hours with solution of 1%. 5%, 10% Arisaematis rhizoma was quantified by trypan blue exclusin method. The control group was treated with 2% FBS in the different duration in 24, 48, 72 hours. We examined DNA of activated caspase by FACS analysis, caspase-3 activity, DNA fragmentation by DNA laddering, activity of HeLa Cells by the XTT assay, activity of MAP kinase by RT-PCR analysis. Results : After 72 hours culture, the growth activities of 1%, 5%, 10% Arisaematis rhizoma-treated Hela cell were significantly reduced with control group, respectively. After 24 hours culture, the ratio of cells showing caspase activity by FACS analysis were increased in 1%, 5%, 10% Arisaematis rhizoma-treated Hela cell. It were also increased in 48 hours culture of 10% and 72 hours culture of 5%, 10% Arisaematis rhizoma-treated Hela cell. In 24, 48 and 72 hours culture, DNA fragmentations of 5%, 10% Arisaematis rhizoma-treated Hela cell were obviously observed. These results meaned that Arisaematis rhizoma induces apoptosis of HeLa cells. It was supported by increased caspase-3 activity and decreased MAP kinase activity according to time periods and concentrations of Arisaematis rhizoma solution. Conclusion : The study shows that Arisaematis rhizoma has inhibitory effect on cell proliferation and induction capacity of apoptosis of human cevical carcinoma cell line, HeLa cells, in vitro. These results suggest that Arisaematis rhizoma should be useful for treatment of human cevical carcinoma.

• Journal of Astronomy and Space Sciences
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• v.36 no.2
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• pp.69-74
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• 2019

Spacecraft requires sufficient power in orbit to perform its mission. So as to comply with system requirements, the sufficient power should be made by a solar cell array by photovoltaic power conversion. A life time of space program depends on its mission considering parts reliability and parts grade. Based on the mission life time, power equipment might be designed to meet specifications. In outer space, solar cell array might generate the dc power by photovoltaic conversion effects and GaInP/GaAs/Ge solar cells are used in this study. Space programs that require more than five years should select parts for high reliability applications. Therefore, reliability analysis for high reliability applications should be performed to check its fulfilment of the requirements. This program should also require more five years for its mission and we performed its analysis using parts count method (PCM) for its reliability. Finally, we performed reliability analysis and obtained quantitative figures found out 99.9%. In this study, we presented the reliability analysis of the 300 W GaInP/GaAs/Ge solar cell array.