Electron paramagnetic resonance oxygen species

Electron paramagnetic resonance (continued) cobalt-thermolysin complex, 28 334, 335 exchange reactions, 31 106-107 glutamine synthetase, 28 358-364 invisible oxygen species, 31 94-95 metalloenzymes, 28 324, 326 metal particle size distribution, 36 99-100, 104... 

Electron paramagnetic resonance has played a major role in the characterization of adsorbed oxygen species and the use of 17Oz has enabled a major advance to be made in the understanding of the nature of the various oxygen species and how they can be bonded to the surface. The use of IR spectroscopy as a technique has tended to be neglected because of the... 

Thus, x-ray powder diffraction, electron paramagnetic resonance, luminescence and Mossbauer data suggest that a complex of Sn, V0+ and oxygen forms that leads to the passivation of vanadium when deposited on the zeolite, and on zeolite/gel mixtures. This complex may be a compound like VpSnO, or similar higher molecular weight species. Evidence of Sn/V all oy formation has not been found from Mossbauer spectroscopy. 

BH4 = Tetrahydrobiopterin CAM = Cytotoxic activated macrophage cNOS = Constitutive nitric oxide synthase CPR = Cytochrome P450 reductase EDRF = Endothelial-derived relaxation factor EPR = Electron paramagnetic resonance spectroscopy IL-1 = Interleukin-1 iNOS = Inducible nitric oxide synthase EPS = Lipopolysaccharide, or endotoxin NMMA = ISp-monomethyl-L-arginine NOS = Nitric oxide synthase ROS = Reactive oxygen species SOD = Superoxide dismutase TNF = Tumor necrosis factor. 

From electron paramagnetic resonance (EPR) measurements, it has been reported that oxygen adsorbed on Au/TiO2 and Au/Ti-SiO2 may form (O2) adsorbed species on Au, Ti, or more likely at the Au-Ti " " interface... 

In addition to their broncho dilatory action in asthma, P-agonistically active substances of diphe-nolic structure offer radical scavenging properties toward reactive oxygen species as shown in a model system by electron paramagnetic resonance spectroscopy and photometric approaches (Zwicker et al. 1998). The substances under study showed activity in superoxide radical scavenging under aprotic and protic conditions as well. The efficiency of the reaction decreased in the order fenoterol > salbuta-mol > reproterol > terbutaline > oxyfedrine when 5,5-dimethyl-l-pyrroline-N-oxide (DMSO) was used as an aprotic solvent. In an aqueous system, the rate constants decreased in the order fenoterol > reproterol > salbutamol. 

The electron paramagnetic resonance probe technique described by Valglimigli et al. (2001) provides a versatile way of gaining rapid and reproducible quantitative measurements of reactive oxygen species in biological systems, ranging from subcel-lular fractions to whole animals and human liver. 

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