• 제목/요약/키워드: epr

검색결과 438건 처리시간 0.032초

Lipid Specificity for Membrane Oxidation Catalyzed by Cytochrome c : An EPR Study

  • 민동필;한상화
    • Bulletin of the Korean Chemical Society
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    • 제17권3호
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    • pp.279-284
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    • 1996
  • Decay of the spin label attached to cytochrome c or to stearic acid has been measured by electron paramagnetic resonance (EPR) spectroscopy to monitor membrane oxidation induced by cytochrome c-membrane interaction. Binding of cytochrome c sequestered the acidic phospholipids and membrane oxidation was efficient in the order linoleic oleic>stearic acid for a fatty acid chain in the acidic phospholipids. The spin label on cyt c was destroyed at pH 7 whereas that on stearic acid embedded in the membrane was destroyed at pH 4, presumably due to different modes of cyt c-membrane interaction depending on pH. Interestingly, cyt c also interacts with phosphatidylethanolamine, an electrically neutral phospholipid, to cause rapid membrane oxidation. Both EPR and fluorescence measurements indicated that electrostatic interaction is at least partially responsible for the process.

갈근 추출물에 의한 염증성 Cytokine 생성 억제 및 Prostaglandin E2 활성 저해에 관한 연구 (Inhibition of Inflammatory-cytokines Production and Prostaglandin E2 Activity by Puerariae Radix Extracts)

  • 김시나;김희석;남경숙;황성완;황성연
    • 한국식품영양과학회지
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    • 제35권1호
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    • pp.28-34
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    • 2006
  • 갈근(Puerariae Radix)의 $70\%$ ethanol 추출물 중 ethyl acetate 분획물(EPR)은 염증성 cytokine을 처리한 마우스 대식세포 및 토기 연골조직세포에서 염증의 발현과 관련된 NO 생성 저해효과를 보였고, 관절조직의 주요 성분 중 하나인 proteoglycan의 분해 억제효과와 관절조직 분해효소인 MMP-9의 활성이 억제되었다. 또한, 통증유발물질인 프로스타글란딘의 유의성 있는 감소를 보여 통증억제 효과가 있음을 확인하였을 뿐만 아니라 초산 유발 진통 효과테스트인 동물 모델에서도 효과적으로 통증을 억제함을 확인하였다. 즉, 갈근의 $70\%$ ethanol 추출물 중 ethyl acetate 분획물(EPR)은 독성의 문제뿐만 아니라, 소염, 진통 효과 및 연골 조직세포의 분해를 억제하는 다양한 효과를 나타내는 장점을 지니고 있어 관절염 치료제의 훌륭한 후보약재가 될 것으로 기대된다.

간단한 구조의 폴딩 EPR4 비터비 검출기 (A Reduced Complexity Folding EPR4 Viterbi Detector)

  • 이천수;기훈재김수원
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.687-690
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    • 1998
  • The full Viterbi detector for EPRML read channel system needs large area due to complex computation. There are several conventional methods to reduce the complexity such as GVA(Generalized Viterbi Algorithm) and BMS(Branch Metric Shift). This paper proposes another method, FVD(Folding Viterbi Detector), that has state transition diagram folded with inverted states. Compared with GVA detector, FVD requires only 61% gates and has lower power consumption and better BER performance.

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구식PC에 함유된 유해물질에 관한 고찰 (Hazardous Substances in the old Personal Computer)

  • 이성호
    • 한국산업정보학회논문지
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    • 제5권4호
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    • pp.47-54
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    • 2000
  • 컴퓨터산업은 일반적으로 청정분야로 알려져 있다. 그러나 컴퓨터는 납, 카드뮴, 수은, 6가 크롬, 프라스틱 등과 같은 고도의 유해물질로 구성되어 있다. 이 논문은 PC에 포함되어 있는 위험물질의 양을 추정하고, 구식 PC의 처리방법인 소각, 매립, 재활용의 문제점을 제시하였다. 또한 e-waste의 해결방안인 EPR가 소개되었다.

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Magnetism in the Layered Structure Compound (C_18H_37NH_3)_2 MNCL_4

  • Lee, K. W.;Lee, C. H.;C. Rhee;Lee, Cheol-Eui;J. K. Kang;Lee, K.-S.
    • Journal of Magnetics
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    • 제2권4호
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    • pp.126-129
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    • 1997
  • We have studied magnetostructural phase transitions in the perovskite-type layered structure compound (C18H37NH3)2 MnCl4 by means of electron paramagnetic resonance (EPR) and superconducting quantum interference device (SQUID) measurements. Distinct slopes were observed in the linear temperature dependences of the Mn++ EPR linewidth in the low and high temperature phases. Besides, linewidth anomalies at the transition temperatures sensitively reflect the magnetic changes arising from the MnCl6 octahedra.

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Electron Paramagnetic Resonance Study of Bis(N-methyl-2-amino-1-cyclopentenedithiocarboxylato)Copper (II)

  • Woo-Seong Kim;Young-Inn Kim;Sung-Nak Choi
    • Bulletin of the Korean Chemical Society
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    • 제11권2호
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    • pp.85-88
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    • 1990
  • The electron paramagnetic resonance (EPR) spectrum of the copper (II) complex with the 2-methylamino-1-cyclo-pentene-1-dithiocarboxylate (acdc) anion, $Cu(N-CH_3acdc)_2$ has been studied in the diamagnetic host lattices afforded by the corresponding divalent nickel, zinc, cadmium and mercury complexes. EPR parameters of the complex support the exclusive use of sulfur atoms by the ligand in metal binding. A combination of host lattice structure and covalency effects can be account for the observed spin-Hamiltonian parameters.

EPR Spectra of ${\alpha}-1,2,3-[HPV(IV)V_2W_9O_{40]}^{6-}$, a Delocalized Mixed-Valence Compound

  • Hyunsoo So;Chul Wee Lee
    • Bulletin of the Korean Chemical Society
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    • 제11권2호
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    • pp.115-118
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    • 1990
  • Solution and frozen solution EPR spectra of $\alpha-1,2,3-[HPV(IV)V_2W_9O_{40}]^{6-}$ have been analyzed. The isotropic hyperfine coupling constants remain constant at 350-77 K, indicating that the unpaired electron is delocalized over three vanadium atoms probably even in the ground state.