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Flash photolysis of NO coupled with time resolved detection of O via resonance fluorescence has been used to obtain rate constants for the reaction O + NO + N2 → NO2 + N2 at temperatures from 217 to 500 K. The measured rate constants obey the Arrhenius equation k = (15.5 ± 2.0) × 10?33 exp(1160 ± 70)/1.987 T] cm6 molecule?2 s?1. An equally acceptable equation describing the temperature dependence of k is k = 3.80 × 10?27/T1.82 cm6 molecule?2 s?1. These results are discussed and compared with previous work. 相似文献
575.
A fabrication platform for electrically mediated optically active biofunctionalized sites in BioMEMS
Powers MA Koev ST Schleunitz A Yi H Hodzic V Bentley WE Payne GF Rubloff GW Ghodssi R 《Lab on a chip》2005,5(6):583-586
We report a new approach for microfluidic optical bioanalysis that is based on the electrically driven assembly of bio-components on a transparent sidewall and the optical detection of the assembled components using planar waveguides. This allows localized electrical signals for bio-assembly and optical signals for bio-detection that can easily be applied in MEMS systems. We demonstrate a BioMEMS design incorporating this scheme and its output signal when using fluorescent detection. 相似文献
576.
Summers JS Base K Boukhalfa H Payne JE Shaw BR Crumbliss AL 《Inorganic chemistry》2005,44(10):3405-3411
Manganese/ligand association dynamics were studied using a series of structurally related anionic phosphorus ester ligand probes [CH(3)OP(O)(X)(Y)(-), where X = CH(3)O, CH(3)CH(2), or H and Y = O, S, or BH(3)]. Reactions of the probe ions with Mn(H(2)O)(6)(2+) and a manganese(III) porphyrin (Mn(III)TMPyP(5+)) were studied in aqueous solution by paramagnetic (31)P NMR line-broadening techniques. A satisfactory linear free energy relationship for reactions of the probe ions with Mn(H(2)O)(6)(2+) and Mn(III)TMPyP(5+) required consideration of both the basicity and solvent affinity of the probe ligands: log(k(app)) = log(k(0)) + alpha pK(a) + beta log(K(ext)), where k(0), alpha, and beta are metal complex dependent parameters and pK(a) and K(ext) represent the measured Bronsted acidity and water/n-butanol extraction constant for the probe anions, respectively. Reactions of Mn(H(2)O)(6)(2+) were relatively insensitive to changes in ligand basicity (alpha = -0.04) and favored the more hydrophilic anions (beta = -0.54). These observations are consistent with a dissociative ligand exchange mechanism wherein the outer-sphere complex is stabilized by hydrogen bonding between Mn(H(2)O)(6)(2+) and the incoming ligand. In contrast, reactions with Mn(III)TMPyP(5+) are accelerated by decreases in both the basicity (alpha = -0.43) and the hydrophilicity (beta = +0.97) of the probe. We conclude that reactions of Mn(III)TMPyP(5+) are also dissociative but that the aromatic groups of the porphyrin provide a hydrophobic environment surrounding the ligand binding site in Mn(III)TMPyP(5+). Thus, the probe/water solvent interactions must be significantly weakened in order to form the outer-sphere complex that leads to ligand substitution. This work demonstrates the utility of phosphorus relaxation enhancement (PhoRE) techniques for characterizing the second coordination sphere environment of metal complexes leading to ligation and will allow comparison of the second coordination spheres of Mn(H(2)O)(6)(2+) and Mn(III)TMPyP(5+) to those of other metal complexes. 相似文献
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G Farace G Lillie T Hianik P Payne P Vadgama 《Bioelectrochemistry (Amsterdam, Netherlands)》2002,55(1-2):1-3
The use of electrochemical impedance spectroscopy (EIS) and the conducting polymer, poly (pyrrole), as an integrated recognition and transduction system for reagentless biosensor systems was demonstrated with two different systems. The first system being an immunoassay for detection of luteinising hormone (LH) with the antibody being entrapped with in the poly (pyrrole) matrix and the second, a construct for DNA hybridisation discrimination able to differentiate single- and double-stranded DNA based on the interaction of the DNA with poly (pyrrole). 相似文献
578.
K. Weber O. Baumann W. Morres Schützler G. D. Eisdon J. R. Stubbs G. Inichoff A. J. J. Vandevelde F. M. Litterscheid L. Barthe E. Dufilho F. Mach W. Lepper E. Kohn-Abrest S. Kavakibi J. Großfeld A. Gronover F. Türk H. C. Waterman H. A. Lepper H. Fincke G. Gahrtz R. Strohecker H. Droop Richmond C. Revis G. A. Payne L. W. Ferris R. E. Remington L. H. Mc Roberts R. Tiemann P. Buttenberg H. Kruspe 《Analytical and bioanalytical chemistry》1928,74(3-4):137-149
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