• Title/Summary/Keyword: Electrophoretic synthesis

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Synthesis and Fate of Yolk Protein-3 in Hyphantria cunea D. (미국흰불나방(Hyphantria cunea D.)의 난황단백질-3의 합성 및 이용)

  • 이상대;김학열
    • The Korean Journal of Zoology
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    • v.34 no.3
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    • pp.394-402
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    • 1991
  • Yolk protein-3 (YP3) was purified from the ovary of Hvpharatria cunea D. and the synthesis and fate during embryogenesis of WP3 were investisated by electrophoresis and fluorography. YP3 purified through gel slice and electrophoretic elution'was determined to have M. W. of 18 Kd and consist of one subunit. Haemolymph and fat body of male and female %were electrophoresed during vifellogenic stages to indentifv the vitellosenin in female. The result showed that there was no distinct difference in electrophoretic patterns betweerl male and female. However, tissue culture of fat body and maturing ovary indicated that YP3 was svuthesized by fat body. Aiso, vP3 in iaid eggs was maintained constant untii naut s artier oviposition and then decreased, indicating that YP3 was drastically used during late embryosenesis. However, a part of YP3 was present even in newly hatched first instar larvae.

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Preparation of SDC electrolyte film for IT-SOFCs by electrophoretic deposition (EPD를 이용한 IT-SOFC용 SDC 전해질 필름의 제조)

  • Lee, Kyeong-Seop;Jo, Chul-Gi;Kim, Young-Soon;Shin, Hyung-Shik
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.158-158
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    • 2009
  • The electrophoretic deposition(EPD) technique with a wide range of novel applications in the processing of advanced ceramic materials and coatings, has recently gained increasing interest both in academic and industrial sector not only because of the high versatility of its use with different materials and their combinations but also because of its cost-effectiveness requiring simple apparatus. Compared to other advanced shaping techniques, the EPD process is very versatile since it can be modified easily for a specific application. For example, deposition can be made on flat, cylinderical or any other shaped substrate with only minor charge in electrode design and positioning[1]. The synthesis of the nano-sized Ce0.2Sm0.8O1.9(SDC)particles prepared by aurea based low temperature hydrothermal process was investigated in this study[2].When we made the SDC nanoparticles, changed the time of synthesis of the SDC. The SDC nanoparticles were characterized with field-emission scanning electron microscope(FESEM), energy dispersive X-ray analysis(EDX), and X-ray diffraction(XRD). And also we researched the results of our investigation on electrophoretic deposition(EPD) of the SDC particles from its suspension in acetone solution onto a non-conducting NiO-SDC substrate. In principle, it is possible to carry out electrophoretic deposition on non-conducting substrates. In this case, the EPD of SDC particles on a NiO-SDC substrate was made possible through the use of a adequately porous substrate. The continuous pores in the substrates, when saturated with the solvent, helped in establishing a "conductive path" between the electrode and the particles in suspension[3-4]. Deposition rate was found to increase its increasing deposition time and voltage. After annealing the samples $1400^{\circ}C$, we observed that deposited substrate.

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Electrochemical Properties of Additive-Free Nanostructured Cobalt Oxide (CoO) Lithium Ion Battery Electrode (첨가제 없이 제작된 나노구조 코발트 산화물 리튬이온 배터리 전극의 전기 화학적 특성)

  • Kim, Juyun;Park, Byoungnam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.5
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    • pp.335-340
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    • 2018
  • Transition metal oxide materials have attracted widespread attention as Li-ion battery electrode materials owing to their high theoretical capacity and good Li storage capability, in addition to various nanostructured materials. Here, we fabricated a CoO Li-ion battery in which Co nanoparticles (NPs) are deposited into a current collector through electrophoretic deposition (EPD) without binding and conductive agents, enabling us to focus on the intrinsic electrochemical properties of CoO during the conversion reaction. Through optimized Co NP synthesis and electrophoretic deposition (EPD), CoO Li-ion battery with 630 mAh/g was fabricated with high cycle stability, which can potentially be used as a test platform for a fundamental understanding of conversion reaction.

Synthesis and Characterization of Graphene Counter Electrode By Electrophoretic Deposition for Dye-Sensitized Solar Cells

  • Choe, Yun-Su;Gong, Jae-Seok;Choe, Hyeon-Gwang;Jeon, Min-Hyeon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.160-160
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    • 2013
  • Dye-sensitized solar cells (DSSCs) have attracted much attention because of their moderate light-to-electricity conversion efficiency, easy fabrication, and low cost. At present, platinum (Pt) is used as a counter electrode in DSSCs. However, it is found that Pt dissolves in iodide electrolyte solutions and creates chemical compound such as PtI4 and H2PtI6. Carbon based materials are one of candidates for a counter electrode of DSSCs. We prepare two types of graphite oxides by different chemical treatments; original graphite oxide, hydrazine treated graphite oxide. Each graphite oxide and magnesium nitrate dispersed in deionized water are prepared as solutions for electrophoretic deposition (EPD). Each graphite oxide electrode is deposited on fluorine-doped tin oxide (FTO) substrate by EPD method. Structural and electrochemical properties of each electrode are investigated by field-emission scanning electron microscopy and electrochemical impedance spectroscopy, respectively.

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Low Temperature Synthesis of TiO2 Films for Application to Dye-sensitized Solar Cells

  • Wi, Jin-Seong;Choe, Eun-Chang;Seo, Yeong-Ho;Hong, Byeong-Yu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.475-475
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    • 2014
  • Dye sensitized solar cells (DSSCs) are regarded as potential inexpensive alternatives to conventional solid-state devices. The flexible version, employing conductive-plastic-film substrates, is appealing for commercialization of DSSCs because it not only reduces the weight and cost of the device but also extends their applications. However, the need for high temperature does not permit the use of plastic-film substrate. So, development of low-temperature methods is therefore realization of flexible DSSCs. In this work, the electrophoretic deposition combined with hydrothermal treatment was employed to prepare nanocrystalline $TiO_2$ thin film at low temperature. We confirmed the prepared $TiO_2$ thin films with different voltages and deposition times in the electrophoretic deposition process. Properties of the $TiO_2$ films were investigated by various analysis method such as X-ray diffraction, field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer.

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Preparation of $Ce_{0.8}Sm_{0.2}O_{x}$ Electrolyte Thin Film for Solid Oxide Fuel Cells by Electrophoretic Deposition (전기영동법을 이용한 고체산화물 연료전지용 $Ce_{0.8}Sm_{0.2}O_{x}$ 전해질 박막 제조)

  • Kim, Dong-Gyu;Song, Min-Wu;Lee, Kyeong-Seop;Kim, Yoen-Su;Kim, Young-Soon;Shin, Hyung-Shik
    • Korean Chemical Engineering Research
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    • v.49 no.6
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    • pp.781-785
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    • 2011
  • In this work, a nano-sized samaria-doped ceria(SDC) was prepared by a urea-based hydrothermal method and characterized by XRD, FESEM and TEM. It was observed that the increase in synthesis time and temperature gave rise to crystallity and particles size. Moreover, the synthesised powders had a excellent ion-conductivity(0.1 S/cm at 600~$800^{\circ}C$) which is suitable for electrolyte of intermediate temperature-solid oxide fuel cell(IT-SOFC). Subsequently for use as electrolyte for anode-supported IT-SOFC, we tried to deposit the SDC powder on a porous NiO-SDC substrate by electrophoretic deposition(EPD) method. From the FESEM observation, a compact

The uniqueness of the plant mitochondrial potassium channel

  • Pastore, Donato;Soccio, Mario;Laus, Maura Nicoletta;Trono, Daniela
    • BMB Reports
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    • v.46 no.8
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    • pp.391-397
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    • 2013
  • The ATP-inhibited Plant Mitochondrial $K^+$ Channel ($PmitoK_{ATP}$) was discovered about fifteen years ago in Durum Wheat Mitochondria (DWM). $PmitoK_{ATP}$ catalyses the electrophoretic $K^+$ uniport through the inner mitochondrial membrane; moreover, the co-operation between $PmitoK_{ATP}$ and $K^+/H^+$ antiporter allows such a great operation of a $K^+$ cycle to collapse mitochondrial membrane potential (${\Delta}{\Psi}$) and ${\Delta}pH$, thus impairing protonmotive force (${\Delta}p$). A possible physiological role of such ${\Delta}{\Psi}$ control is the restriction of harmful reactive oxygen species (ROS) production under environmental/oxidative stress conditions. Interestingly, DWM lacking ${\Delta}p$ were found to be nevertheless fully coupled and able to regularly accomplish ATP synthesis; this unexpected behaviour makes necessary to recast in some way the classical chemiosmotic model. In the whole, $PmitoK_{ATP}$ may oppose to large scale ROS production by lowering ${\Delta}{\Psi}$ under environmental/oxidative stress, but, when stress is moderate, this occurs without impairing ATP synthesis in a crucial moment for cell and mitochondrial bioenergetics.

Polyphosphate Kinase Affects Oxidative Stress Response by Modulating cAMP Receptor Protein and rpoS Expression in Salmonella Typhimurium

  • Cheng, Yuanyuan;Sun, Baolin
    • Journal of Microbiology and Biotechnology
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    • v.19 no.12
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    • pp.1527-1535
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    • 2009
  • Polyphosphate (polyP) plays diverse physiological functions in prokaryotes and eukaryotes, but most of their detailed mechanisms are still obscure. Here, we show that deletion of polyphosphate kinase (PPK), the principal enzyme responsible for synthesis of polyP, resulted in augmented expression of cAMP receptor protein (CRP) and rpoS and lowered $H_2O_2$ sensitivity in Salmonella Typhimurium ATCC14028. The binding of cAMP-CRP complex to rpoS promoter and further stimulation of its transcription were proved through electrophoretic mobility shift assay, lacZ fusion, and exogenous cAMP addition, respectively. The rpoS expression increased in cpdA (cAMP phosphodiesterase coding gene) mutant, further suggesting that cAMP-CRP upregulated rpoS expression. These results demonstrate that PPK affects oxidative stress response by modulating crp and rpoS expression in S. Typhimurium.

Synthesis of WS2 by electrophoretic depsoition and sulfurization. (전기 영동 및 황화 처리를 이용한 WS2 합성에 관한 연구)

  • Kim, Min-Gyeong;Park, Yeong-Bae;Lee, Gyu-Hwan;Choe, Seung-Mok
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.167.1-167.1
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    • 2017
  • 전이금속 디칼코게나이드는 서로 다른 전이 금속원소와 칼코겐 원소의 결합으로 이루어진 층상 구조의 물질이다. 그 중 텅스텐 이황화물($WS_2$)은 전이금속 화합물로써 풍부한 매장량으로 인하여 가격면에서 매우 저렴하며, 높은 온도에서도 잘 견딜 수 있는 열 내구성이 강해 물 분해 반응에서 촉매로 사용될 수 있는 가능성이 제시되었다. 이러한 $WS_2$을 매장량이 적은 고비용의 백금계 촉매를 대체하기 위한 물질로서 많은 연구가 활발히 진행되고 있다. 본 연구에서는 $WO_3$ 콜로이드 용액을 전기 영동 및 황화 처리 이용하여 $WS_2$를 합성하여 수소 발생 반응(Hydrogen Evolution Reaction, HER)촉매로서의 가능성을 확인하였다.

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Synthesis and Characterization of Hyaluronic Acid-α-Cyclodextrin Conjugate as the Potential Carrier of PEGylated Drugs

  • Sivasubramanian, Maharajan;Park, Jae-Hyung
    • Journal of Pharmaceutical Investigation
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    • v.40 no.4
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    • pp.219-223
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    • 2010
  • The hyaluronic acid (HA) conjugate bearing $\alpha$-cyclodextrin ($\alpha$-CD) was synthesized as the potential carrier of poly(ethylene glycol) (PEG)-drug conjugates. The HA conjugate was prepared by the reaction between the carboxylic acid of HA and the primary amine of $\alpha$-CD in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1-hydroxybenzotriazole. The chemical structure of the conjugate was confirmed using $^1H$ NMR and FT-IR spectroscopy. The conjugate could form nano-sized particles in the presence of PEG by forming the inclusion complexes between $\alpha$-CD at the backbone of HA, which was demonstrated using electrophoretic light scattering and field emission transmission electron microscopy. It is anticipated that this novel kind of nanoparticles can serve as a useful delivery system for PEGylated drugs.