• 제목/요약/키워드: Chelates

검색결과 106건 처리시간 0.027초

졸-겔 법에 의한 $\gamma-LiAlO_2$ 화이버의 제조 및 특성 (Preparation and Characteristics of $\gamma-LiAlO_2$ Fibers by the Sol-Gel Method)

  • 현상훈;홍성안;신현철
    • 한국세라믹학회지
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    • 제32권2호
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    • pp.197-208
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    • 1995
  • ${\gamma}$-LiAlO2 fibers for fiber reinforced molten carbonate fuel cell (MCFC) matrix have been produced from LiAlO2 complex polymeric sols using the sol-gel process. The stable and spinnable LiAlO2 sols could be synthesized by mixing LiNO3 alcohol solutions in aluminum complex polymeric sols prepared through the condensationpolymerization reaction of 1 more of aluminum tri-sec-butoxide with 0.55 mole of mixed chelates (mole ratio of acetylaceton/triethanolamine=0.25/0.3). It was found that the viscosity range for fiber-spinning should be higher than 30 poise. The defect-free flexible ${\gamma}$-LiAlO2 fibers with the average tensile strength of 350 MPa could be obtained when the spinned fibers were heat-treated to 120$0^{\circ}C$ on the specified heating schedule after dried at room temperature.

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Effects of pH on Purification of GFPuv/Cytochrome c-552 Fusion Protein

  • 이상온;홍을재;최정우;홍억기
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.539-542
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    • 2003
  • SDS-PAGE 결과 elution pH에 따라 분리되는 band pattern은 비슷하게 2band의 양상을 보이지만, FI값을 비교하여 보았을 때 다른 pH보다 8.0에서 가장 높은 수준을 보였으므로 GFPuv/cytochrome c-552 fusion Protein의 분리 ${\cdot}$ 정제에 가장 적합한 pH를 8.0으로 정하였다.

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Zirconium Pyrithione 착물의 항균력 (Antimicrobial Activity of Zirconium Pyrithione Complex)

  • 권중무;이계주
    • Journal of Pharmaceutical Investigation
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    • 제18권3호
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    • pp.107-111
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    • 1988
  • Zr, Cu, Zn and Fe-pyrithione complexes were prepared in aqueous medium and their antimicrobial activities were evaluated by MIC and cylinder plate methods against Bacillus subtilis, Sarcina lutea, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Trichophyton mentagrophytes, Candida albicans, Asperillus niger and Saccharomyces cerevisiae. Zr-pyrithione possessed most potent activities among the metal complexes against a wide range of microorganisms, especially Gram positive, B. subtilis, S. aureus and fungus, C. albicans. And all of the metal complexes synthesized were more active than pyrithione base. Fe(III)-pyrithione complex has an equal potency to Zn-pyrithione in general but it showed potent activity against B. subtilis microorganism than Zn-pyrithione.

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Hepatocellular carcinomas: correlation of enhancement degree with pathologic grades triple contrast MR imaging

  • Kim, Joo-Hee;Kim, Myeong-Jin;Park, Young-Nyun;Kim, Kyung-Sik;Lee, Woo-Jung
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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    • pp.108-108
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    • 2001
  • Purpose: To correlate the histological differentiation of hepatocellular carcinomas (HCCs) with finding on triple contrast-enhanced MR imaging using gadolinium-chelates, superparamganetic ire oxides (SPIO), and mangafodipir trisodium. Method: Ten patients with proven HCC underwent triple contrast-enhanced MRI befo surgical resection. Subjective ratings of the enhancement pattern and degree were compare with the histological grades determined on surgical specimen. Quantitative measurements signal-to-noise ratio (S/N) of the lesion and the lesion-to-liver contrast-to-noise ratio C/N on the enhanced MR images, and the degree of S/N and C/N changes between the unenhanced and enhanced images were also correlated with the histological grades.

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MR조영제와 분자영상 (MR Contrast Agents and Molecular Imaging)

  • 문우경
    • 대한핵의학회지
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    • 제38권2호
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    • pp.205-208
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    • 2004
  • The two major classes of magnetic resonance (MR) contrast agents are paramagnetic contrast agents, usually based on chelates of gadolinium generating T1 positive signal enhancement, and super-paramagnetic contrast agents that use mono- or polycrystalline iron oxide to generate strong T2 negative contrast in MR images. These paramagnetic or super-paramagnetic complexes are used to develop new contrast agents that can target the specific molecular marker of the cells or tan be activated to report on the physiological status or metabolic activity of biological systems. In molecular imaging science, MR imaging has emerged as a leading technique because it provides high-resolution three-dimension maps of the living subject. The future of molecular MR imaging is promising as advancements in hardware, contrast agents, and image acquisition methods coalesce to bring high resolution in vivo imaging to the biochemical sciences and to patient care.

새로운 2-Quinazolylacetonitrile 유도체들의 합성 (Synthesis of New 2-Quinazolylacetonitrile Derivatives)

  • 김정환;민경수
    • 대한화학회지
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    • 제45권6호
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    • pp.532-537
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    • 2001
  • H-chelate형태의 2-Quinazolylacetonitrile유도체들은 2-cyanomethylquinazoline에 여러가지 친전자체들, 즉, 4-chloroquinazoline, 4-chloro-2-phenylquinazoline, 4,6-dichloropyrinidine, 4,6-dichloro-2-phenylpyrimidine, 4,6-dichloro-5-phenylpyrimidine, 2-chloroauinoxaline,1,3- dichloroisoquinoline, 2,6-dichloropyrazine, 2-chloropyrazine, 4,6-dichloro-2,5-diphenylpyrimidine 등을 반응시켜 얻을 수 있었다. 합성된 H-chelate화합물들은 polymethine계의 발색단 구조를 가지게 된다. 이들 화합물에 대한 구조는 분광학적인 방법으로 분석 확인 하였다.

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H-킬레이트가 있는 피리미딘 유도체들의 합성 (The Synthesis of Pyrimidine Derivatives Containing H-Chelate)

  • 김정환;서정협
    • 대한화학회지
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    • 제34권6호
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    • pp.637-640
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    • 1990
  • 분자내에서의 전자에너지 전달시스템의 골격으로서 Bis (4,6-dichloropyrimidine-5-yl) alkanes류를 합성하였으며, 이화합물과 2-cyanomethylquinoline을 반응시켜 $\alpha$-(4-cyanomethylquinoline-6-chloropyrimidine-5-yl)-$\omega$-(4,6-dichloropyrimidine-5-yl) alkanes의 H-chelate를 합성하였다. 이들 화합물에 대한 구조는 분광학적인 방법으로 연구하였다.

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Recycling of chelating agents after extraction of heavy metals contaminated in soil

  • Jung, Oh-Jin
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제10권S_3호
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    • pp.139-148
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    • 2001
  • Heavy metals such as Cu, Ni, Cd, and Pb were chemically extract from the contaminated soils using the chelating agents, EDTA and DTPA. These chemical extraction have been focused on its applicability to a wide range of soils. Results of extractive efficiency for heavy metal follow the order : Cu-EDTA $\geq$ Ni-EDTA > Pb-EDTA > Cd-EDTA > Cu-DTPA> Pb-DTPA. This result is coincided with order of conditional formation constants(Kr) of metal-chelate agent. The second study involved the recovery of the metals and EDTA from complex solutions by an electromembrane process. The overall processes of regeneration, recovery, and reuse were evaluated. The electrochemical studies showed that copper could be chosen as an electrode to plate Cd, Cu, and Pb. At least 95% of 75 of EDTA and associated Cu or Pb could be recovered by the electromembrane process. Recovery of Cd by electodeposition was not possible with the copper electrode. The percent EDTA recovery is equal to the percentage of metal electroplated from the chelates.

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Synthesis, Characterization and Spectrophotometric Studies of Seven Novel Antibacterial Hydrophilic Iron(II) Schiff Base Amino Acid Complexes

  • Shaker, Ali M.;Nassr, Lobna A.E.;Adam, Mohamed S.S.;Mohamed, Ibrahim M.A.
    • 대한화학회지
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    • 제57권5호
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    • pp.560-567
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    • 2013
  • A series of new Iron(II) Schiff base amino acid complexes derived from the condensation of amino acid and sodium 2-hydroxybenzaldehyde-5-sulfonate have been synthesized. The complexes were characterized by elemental, electronic, IR spectral analyses and conductance measurements. The stability and solubility of the prepared complexes were determined. Two spectral methods used to determine the stoichiometry of the prepared complexes which exhibited divalent tridentate coordination and formed chelates of octahedral structures. The antibacterial activity of the prepared complexes has been tested against Bacillus cereus, Pseudomonas aeruginosa and Micrococcus bacteria. The effect of HCl on investigated complexes studied spectrophotometrically.