• Title/Summary/Keyword: auxiliary cells

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Synergistic Anti-tumor Effect of KLF4 and Curcumin in Human Gastric Carcinoma Cell Line

  • Ji, Jun;Wang, He-Shuang;Gao, Yan-Yan;Sang, Li-Min;Zhang, Li
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7747-7752
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    • 2014
  • Kr$\ddot{u}$ppel-like factor 4 is a transcription factor which plays an important role in development and progression of various carcinomas. Curcumin characterized by excellent anti-cancer properties is regarded as a serviceable natural compound used in carcinoma therapy. This study aimed at exploring the impact of KLF4 overexpression in cooperation with curcumin on the proliferation, apoptosis and invasion of human gastric carcinoma BGC-823 cells. Flow cytometry analysis, CCK-8 assays, transwell assays and Western blot results showed that KLF4 overexpression combined with curcumin had significant anti-proliferation, pro-apoptosis and anti-invasion effects on BGC-823 cells. We also found that KLF4 had synergistic effects with curcumin, better promoting apoptosis and inhibiting proliferation and invasion of gastric carcinona cells. These results indicate that KLF4 could be used as a potential therapeutic target; curcumin could act as an auxiliary and provide a promising therapeutic strategy in stomach cancer.

A Modularized Equalizer for Supercapacitor Strings in Hybrid Energy Storage Systems

  • Gao, Zhigang;Jiang, Fenlin
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1469-1482
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    • 2016
  • In hybrid energy storage systems, supercapacitors are usually connected in series to meet the required voltage levels. Equalizers are effective in prolonging the life of hybrid energy storage systems because they eliminate the voltage imbalance on cells. This study proposes a modularized equalizer, which is based on a combination of a half-bridge inverter, an inductor, and two auxiliary capacitors. The proposed equalizer inherits the advantages of inductor-based equalization systems, but it also offers unique merits, such as low switching losses and an easy-to-use control algorithm. The zero-voltage switching scheme is analyzed, and the power model is established. A fixed-frequency operation strategy is proposed to simplify the control and lower the cost. The switching patterns and conditions for zero-voltage switching are discussed. Simulation results based on PSIM are presented to verify the validity of the proposed equalizer. An equalization test for two supercapacitor cells is performed. An experimental hybrid energy storage system, which consists of batteries and supercapacitors, is established to verify the performance of the proposed equalizer. The analysis, simulation results, and experimental results are in good agreement, thus indicating that the circuit is practical.

A Novel Cell Balancing Circuit for Fast Charge Equalization (빠른 전하 균일화를 위한 새로운 구조의 셀 밸런싱 회로)

  • Park, Dong-Jin;Choi, See-Young;Kim, Yong-Wook;Kim, Rae-Young
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.2
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    • pp.160-166
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    • 2015
  • This study proposes an improved cell balancing circuit for fast equalization among lithium-ion (Li-ion) batteries. A simple voltage sensorless charge balancing circuit has been proposed in the past. This cell balancing circuit automatically transfers energy from high-to low-voltage battery cells. However, the circuit requires a switch with low on-resistance because the balancing speed is limited by the on-resistance of the switch. Balancing speed decreases as the voltage difference among the battery cells decrease. In this study, the balancing speed of the cell balancing circuit is enhanced by using the auxiliary circuit, which boosts the balancing current. The charging current is determined by the nominal battery cell voltage and thus, the balancing speed is almost constant despite the very small voltage differences among the batteries. Simulation results are provided to verify the validity of the proposed cell balancing circuit.

Morphology and Reproduction of Polysiphonia atlantica Kapraun et J. Norris (Rhodomelaceae, Rhodophyta) (홍조 Polysiphonia atlantica Kapraun et J. Norris의 형태와 생식)

  • Kim, Myung-Sook;Lee, In-Kyu
    • Journal of Plant Biology
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    • v.39 no.1
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    • pp.23-29
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    • 1996
  • Morphology and reproduction of Polysiphonia atlantica Kapraun et J. Norris were studied on the basis of field and laboratory cultured materials collected from the coast of Korea. The plants consisted of prostrate and erect axes with an extremely soft flaccid texture. Axes were ecorticated and had four pericentral cells. The plants except for female gametophytes had few trichoblasts. Branches in the upper portion of the thallus grew to the same level, resulting in a flat-top form. Tetrasporangia were arranged in straight series. Spermatangial branches replaced whole trichoblasts and had a 1-2 celled serile tip. The procarp had a four celled carpogonial branch. After fertilization, the carpogonium contancted the surface of the supporting cell. The formation of the auxiliary cell from the supporting cell was somewhat delayed P. atlantica from Korea was similar to P. subtilissima Montagne in some features. However, the taxonomic differences between the two species were identified in the development of branches and the number of sterile cells at the tip of spermatangial branches.

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Antitumor Activity of the Novel Human Cytokine AIMP1 in an in vivo Tumor Model

  • Lee, Yeon-Sook;Han, Jung Min;Kang, Taehee;Park, Young In;Kim, Hwan Mook;Kim, Sunghoon
    • Molecules and Cells
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    • v.21 no.2
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    • pp.213-217
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    • 2006
  • Although AIMP1 (previously known as p43) is one of three auxiliary proteins bound to a macromolecular aminoacyl tRNA complex, it is also secreted as a cytokine controlling both angiogenesis and immune responses. Here we show that systemically administered purified recombinant human AIMP1 had anti-tumor activity in mouse xenograft models. In Meth A-bearing Balb/c mice, tumor volume increased about 28 fold in the vehicle treatment group, while an increase of about 16.7 fold was observed in the AIMP1-treated group. We also evaluated the anti-tumor activity of AIMP1 in combination with a sub-clinical dose of the cytotoxic anti-tumor drug, paclitaxel. The growth of NUGC-3 human stomach cancer cells was suppressed by 84% and 94% by the combinations of 5 mg/kg paclitaxel + 25 mg/kg AIMP1 (p = 0.03), and 5 mg/kg paclitaxel + 50 mg/kg AIMP1 (p = 0.02), respectively, while 5 mg/kg paclitaxel alone suppressed growth by only 54% (p = 0.02). A similar cooperative effect of AIMP1 and paclitaxel was observed in a lung cancer xenograft model. These results suggest that AIMP1 may be useful as a novel anti-tumor agent.

Evaluation on the Dismantling Activities of the KRR-2 Radioisotope Production Facilities (연구로 2호기 동위원소생산시설 해체활동 평가)

  • 박승국;천은영;박진호
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.671-675
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    • 2003
  • In accordance with the KRR-1 & 2 decommissioning project, the decontamination and dismantling activities of the KRR-2 auxiliary facilities, radioisotope production facilities, were completed from Aug 2001 to Dec 2002. The auxiliary facilities were composed of the concrete hot-cell, lead hot-cells and several laboratories for the radioisotope production. The dismantling objects are home hoods, experimental desks, sinks, and contaminated inner facilities. For the purpose of the safe decommissioning activity, the method statements and working procedures were set up. The manpower of the total 20,933 man-hour was required and several dismantling equipments were also. The maximum surface contamination is: 9.24 Bq/$\textrm{cm}^2$ in removable contamination and 350,000 cpm in fixed contamination. The total amount of 62.146 Ton was raised as dismantled waste with kinds of the concretes, wood, steels, etc. The collective dose was evaluated as 0.33 mam-mSv during this period.

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The Enhanced Physico-Chemical and Electrochemical Properties for Surface Modified NiO Cathode for Molten Carbonate Fuel Cells (MCFCs)

  • Choi, Hee Seon;Kim, Keon;Yi, Cheol-Woo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1305-1311
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    • 2014
  • The nickel oxide, the most widely used cathode material for the molten carbonate fuel cell (MCFC), has several disadvantages including NiO dissolution, poor mechanical strength, and corrosion phenomena during MCFC operation. The surface modification of NiO with lanthanum maintains the advantages, such as performance and stability, and suppresses the disadvantages of NiO cathode because the modification results in the formation of $LaNiO_3$ phase which has high conductivity, stability, and catalytic activity. As a result, La-modified NiO cathode shows low NiO dissolution, high degree of lithiation, and mechanical strength, and high cell performance and catalytic activity in comparison with the pristine NiO. These enhanced physico-chemical and electrochemical properties and the durability in marine environment allow MCFC to marine application as a auxiliary propulsion system.

Effect of air flow channel configuration on performance of direct methanol fuel cells. (공기극 채널 형상이 직접 메탄올 연료전지의 성능에 미치는 영향)

  • Hwang, Yong-Sheen;Choi, Hoon;Cha, Suk-Won;Lee, Dae-Young;Kim, Seo-Young
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.137-140
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    • 2007
  • We consider the optimum air flow channel design for DMFC's in the present study. The effect of pressure drop across the inlet and outlet of a stack on the performance of a DMFC is the optimization of such geometric parameters is crucial to minimize the parasitic power usage by the auxiliary devices such as fuel pumps and blowers. In this paper, we present how the pressure drop control can optimize the driving point of a DMFC stack. Further, we show how the optimal fuel utilization ratio can be achieved, not degrading the performance of DMFC stacks. Overall, we discuss how the flow channel design affects the selection of balance of plant(BOP) components, the design of DMFC systems and the system efficiency.

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Analysis of the FuelCell Battery Hybrid Power System (연료전지 축전지 복합 동력원의 구동 특성)

  • Lee, Bong-Do;Shin, Dong-Ryul
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1322-1324
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    • 2001
  • FuelCell/Battery hybrid power systems were studied to develop high efficient zero-emission fuel cell electric vehicles. Fuel cells were used as an auxiliary energy source and batteries were used as a transient power source. The fuel cell system is used to supply the average power demand. Dynamic response of the hybrid systems was simulated using PSPICE program and also tested experimentally. The results can be used to design the interface module and to determine the power requirement between the fuel cell unit and the battery pack.

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A new Areal Selective Dimming Method of Mercury-free Flat Fluorescent Lamps for LCD Backlighting

  • Jung, Jae-Chul;Seo, In-Woo;Oh, Byung-Joo;Kim, Hyuck;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1189-1192
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    • 2008
  • A new mercury-free flat fluorescent lamp with a single cell having dimension 2.2inches across the diagonal, had been developed which shows a wide, stable operating voltage margin, high luminance and luminous efficacy by adopting the bipolar pulse drive scheme. In this paper, the single cell is expanded into a multi-structured configuration to realize a 32inch sized panel across the diagonal by a simple repetition of the single cells. A driving scheme is proposed for a 2-bit areal selective dimming using dual auxiliary electrodes and bipolar drive scheme.

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