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DMPO 와 ㆍOH 의 Spin添加生成物에 대한 EPR 分析 및 ㆍOH 의 毒性作用
김정렬,이미녕,박윤창 성균관대학교 기초과학연구소 1989 論文集 Vol.40 No.2
The hydroxyl radical (·OH) generated from the Iron-catalyzed Haber-Weiss reaction was detected. The ability of Fe(Ⅱ) to this reaction depends upon the particular ligands around the metal ion. The formation of hydroxyl radical, spin trapped with 5, 5-dimethyl-1-pyrroline-N-oxide (DMPO), increased with the amount of ATP added in the Fe (Ⅱ)-H_2O_2 system. Specially, when the concentration of H_2O_2 was high, the perhydroxyl radicals were formed from the system. Human erythrocyte ghosts were covalently labeled with 4-maleimido-2,2,6,6-tetramethylpiperidine-N-oxyl(4-Maleimido-Tempo) and their electron paramagnetic resonance(EPR) spectra revealed two major binding environments representing strongly (h_1) and weakly (h_2) immobilized) species. The ratio of h_2/h_1, determined from the respective peak amplitudes, decreased from 14.8 to 5.5 when the labeled ghosts were exposured with hydroxyl radicals produced in the system, whereas lipid peroxidation of erythrocyte ghosts was increased with the concentration of hydroxyl radicals. These effects suggested that the fluidity of membrane and/or protein mobility were decreased as a result of lipid peroxidation and the structural and the functional alterations of membrane were. initiated by hydroxyl radicals.
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박윤창,이미녕,김태관,이성기 한국분석과학회 2005 분석과학 Vol.18 No.3
The N hyperfine coupling constants (aN) of di-t-butyl nitroxide (DTBN) radicals in water-solvent system were measured with EPR spectroscopy. Various kinds of the solvents with different polarity such as acetone, dimethylsulfoxide (DMSO), methanol, ethanol and 1-propanol were applied and studied. Equilibrium constants for the solvation equilibrium and the solvent parameters (ET, molar transition energy) of various water-solvent system were obtained from the experimental results and are presented. The aN values were plotted as a function of mole fraction of the solvent. In case of water-DMSO, water-ethanol and water-1-propanol system, slight negative deviations from the straight line were observed. In water-acetone system, the absorption wavelength () due to → * transition increased linearly with the increase of mole fraction of acetone. The relationship between aN of DTBN and due to 걺 * transition in water-acetone and water-DMSO system was examined. It was found that the electronic structure of the nitroxide radicals is stablized from the fact that the N hyperfine coupling constants of DTBN radicals are greatly unaffected in the environment of water-solvent system.
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무기 이소시안화 및 티오시안화 전이금속 화합물의 구조에 관한 연구
박윤창,지광용,이미녕,이영희 성균관대학교 기초과학연구소 1989 論文集 Vol.40 No.1
IR, UV 그리고 EPR 분석을 통해 〔R_4N〕_2 〔M(NCX)_4〕 (이 때, R=CH_3^+, C_2H_5^+; M=Cd Cu, Zn, X=O, S) 화합물의 착이온에서 중심 금속이 N과 결합하고 있는지 아니면 O, S와 결합하고 있는지를 연구했다. 위의 모든 화합물은 금속이 N과 결합된 것으로 규명되었다. Cd(Ⅱ)과 Cu(Ⅱ) 화합물은 일그러진 정사면체 구조에 의해 C-N, C-S 신축진동수의 분리를 보였다. IR 스펙트럼에서 〔(C_2H_5)_4N〕_2 〔Cu(NCS)_4〕는 단일선의 C-N 신축진동수를 보인 반면, 〔(CH_3)_4N〕_2 〔Cu(NCS)_4〕는 일그러진 정사면체 구조에 기인한 이중선을 보였다. 〔(C_2H_5)_4N〕_2 〔(Cu(NCS)_4〕는 d-d 전이로 판단되는 넓은 전자흡수띠가 438nm 근처에서 관찰된 반면, 〔(CH_3)_4N〕_2 〔Cu(NCS)_4〕는 d-d전이에 의한 흡수띠가 관찰되지 않았다. 5% Cu(Ⅱ)이 혼입된 〔(C_2H_5)_4N〕_2 〔Cd(NCS)_4〕의 EPR 스펙트럼은 비등방성 구조를 지녔으나, 〔(CH_3)_4N〕_2 〔Cd(NCS)_4〕는 비등방성 뿐만 아니라 정규적인 정사면체 구조의 증거인 등방성을 상온에까지 지녔다. IR, UV and EPR spectra of the compounds whose formulas are 〔R_4N〕_2 〔M(NCX)_4〕, where R=CH_3^+, C_2H_5^+ and M=Cd, Cu, Zn;X=O, S have been studied in order to investigate whether the isocyanato, thiocyanato group is bonded to the central metal through the nitrogen atop or through the sulfur, oxygen atom in those complex ions. All above complexes showed that the metal is linked through the nitrogen atom. It was turned out to be that. the splitting in C-N and C-S stretching frequencies of Cd(Ⅱ) and Cu(Ⅱ) compounds is due to the distorted tetrahedral structure of those compounds. While IR spectrum of 〔(C_2H_5)_4N〕_2 〔Cu(NCS)_4〕 showed singlet C-N stretching frequency, 〔(CH_3)_4N〕_2 〔Cu(NCS)_4〕 showed doublet which indicates that the compound has a distorted tetrahedral structure. 〔(C_2H_5)_4N〕_2 〔Cu(NCS)_4〕 was observed to have a broad electronic absorption band near 438 nm which originates from d-d transition. On the other hand, 〔(CH_3)_4N〕_2 〔Cu(NCS)_4〕 did not show an absorption band due to d-d transition. EPR. spectrum of Cu(Ⅱ) doped 〔(C_2H_5)_4N〕_2 〔Cd(NCS)_4〕 showed anisotropic structure and 〔(CH_3)_4N〕_2 〔Cd(NCS)_4〕 showed both anisotropic and isotropic structure even at room temperature which is an evidence of regular tetrahedral structure.
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