Fluorescence kinetic studies

Laser Photolysis-Laser-Induced Fluorescence Kinetic Studies... 

On the other hand, in order to reduce the number of functional groups attached onto the CNT surface, a more elegant procedure involves the synthesis of SWCNTs functionalized polyamidoamide dendrimers. In this way, the extended conjugated n-system is not irreversibly perturbed and it is possible to modify further the periphery of the dendrimer with electron donor molecules to mediate the electron transfer process [131], Also in this case, the fluorescence kinetic studies brought about the existence of short-lived (0.04 0.01 ns) and long-Uved (8.6 1.2 ns) excited states. This kind of construct plays the unambiguous role of antenna system on the nanotube surface. 

The high fluorescence emission of pyrene makes it a useful fluorescence probe to study multistepped host-guest reactions (in the previous example 1 1 and 2 1 additions), by time-resolved fluorescence, steady-state fluorescence, and fluorescence kinetic studies. 

Ide, T., E. Iwasaki, Y. Matsumi, J.-H. Xing, K. Takahashi, and T.J. Wallington (2008), Pulsed laser photolysis vacuum UV laser-induced fluorescence kinetic study of the reactions of Cl( P3/2) atoms with ethyl formate, n-propyl formate, and n-butyl formate, Chem. Phys. Lett., 467, 70-73. 

Sensitivity levels more typical of kinetic studies are of the order of lO molecules cm . A schematic diagram of an apparatus for kinetic LIF measurements is shown in figure C3.I.8. A limitation of this approach is that only relative concentrations are easily measured, in contrast to absorjDtion measurements, which yield absolute concentrations. Another important limitation is that not all molecules have measurable fluorescence, as radiationless transitions can be the dominant decay route for electronic excitation in polyatomic molecules. However, the latter situation can also be an advantage in complex molecules, such as proteins, where a lack of background fluorescence allow s the selective introduction of fluorescent chromophores as probes for kinetic studies. (Tryptophan is the only strongly fluorescent amino acid naturally present in proteins, for instance.)... 

Reviews fast transient kinetic studies of bioiogicai moiecuies (exciuding fluorescence studies). 

Fluorescence quenching studies of these alkylated FBAs in aqueous solution were carried out using spectroscopic techniques. For the higher members of each series, plots of fluorescence quantum yield against agent concentration showed a sharp decrease in fluorescence intensity at a specific concentration, in contrast to the smoothly decreasing curve characteristic of the lower alkyl or unsubstituted FBAs. The kinetics of fluorescence... 

A method has been proposed for evaluation of LIP concentration in living cells based on the fluorescent probe calcein (Breuer etai, 1995 Epsztejn etai, 1997). The authors assumed that calcein bound Fe2+. However, a more recent thermodynamic and kinetic study indicates that the preferred form bound is Fe3+, and that calcein is a good chemosensor of Fe3+ (Thomas, etai., 1999). The iron... 

Rettig W., Kinetic Studies on Fluorescent Probes Using Synchrotron Radiation, in Fluorescence Spectroscopy New Methods and Applications, Wolfbeis O.S. (Ed.), Springer, Berlin-Heidelberg, Germany, 1993 pp 13-24. 

Kinetic studies were attempted at 4, 15, 25 and 37 °C, but the colloids tended to aggregate at all temperatures above 4°C. Four models were used to determine the binding mechanisms from the kinetic data. A detailed analysis of binding at 4 °C, was made. Models were set up involving one or two surface sites which also satisfied the overall kinetics but the analyses were not definitive. Although it was demonstrated that the cells were capable of endocytosis of fluorescence-conjugated transferrin, there was no evidence for the endocytosis of the cationic colloids. 

Fujita Y, Zenitani B, Nakao Y, Matsubara T (1972) Bacteriological studies on diseases of cultured laver. II. Bacteria associated with diseased laver. Bull Jap Soc Sci Fish 36 565-569 Gachon CMM, Kupper H, Kupper FC, Setlik I (2006) Single-cell chlorophyll fluorescence kinetic microscopy of Pylaiella littoralis (Phaeophyceae) infected by ChytricUum pofysiphoniae (Chytridiomycota). Eur J Phycol 41 395—403... 

W. Rettig, Kinetic studies on fluorescence probes using synchrotron radiation, in Fluorescence Spectroscopy New Methods and Applications (0. S. Wolfbeis, ed.), pp. 31-47, Springer-Verlag, Berlin (1993). 

W. R. Laws, J. B. A. Ross, H. R. Wyssbrod, J. M. Beechem, L. Brand, and J. C. Sutherland, Time-resolved fluorescence and H NMR studies of tyrosine and tyrosine analogues Correlation of NMR-determined rotamer populations and fluorescence kinetics, Biochemistry 25, 599-607 (1986). 

N. L. Thompson and D. Axelrod, Immunoglobulin surface-binding kinetics studied by total internal reflection with fluorescence correlation spectroscopy, Biophys. J. 43, 103-114 (1983). 

Griinhagen HH, Iwatsubo M, Changeux JP. 1977. Fast kinetic studies on the interaction of cholinergic agonists with the membrane-bound acetylcholine receptor from Torpedo marmorata as revealed by quinacrine fluorescence. Fur J Biochem 80 225-242. 

The same mechanism was also proposed by Herkstroeter and coworkers,who carried out absorption and fluorescence measurements on the interaction of 4-pyrenyl butanoate with gamma cyclodextrin. No kinetic studies, however, have yet been performed on these systems in order to verify the proposed mechanism. 

Physico-chemical properties. In the fifties and sixties, several studies on the conformation of ACTH in solution were carried out. Among the used techniques were ORD, CD, fluorescence depolarization studies and kinetics of deuterium hydrogen exchange (for a review see ref. 2). The results pointed to a highly flexible random coil in solution however, Eisinger (40) found that the distance between Tyr and Trp [in ACTH-(1-24)] as measured by excitation spectroscopy, was in better agreement with some form of loop or helical structure. In addition. Squire and Bewley noted 11-15% helical content, located in the N-terminal 1-11 part of the molecule, when measuring the ORD of ACTH at pH 8.1 (41) (a random coil was found at neutral and acidic pH values, 2). 

Wu, C.-H., and H. Niki, Fluorescence Spectroscopic Study of Kinetics of Gas-Surface Reactions between Nitrogen Dioxide and Adsorbed Pyrene, Environ. Sci. Technol, 19, 1089-1094 (1985). 

Diphenylbenzo[c]furan is one of the fastest singlet oxygen acceptors known and has become a standard compound in preparative and kinetic studies in the O2 ( Ag) field its disappearance can easily be followed either by measuring the absorbance in the 415 nm region or by fluorescence emission (e.g., at 458 nm) Table VIII summarizes work where 138 has been used either for preparative purposes or for mechanistic investigations. 1 7.342-349,3 52,354-3 59,362-394... 

Fluorescence measurements of HO have been a common feature of laboratory kinetics studies of the reaction-rate coefficients of HO with various molecules and of studies of this free radical in combustion systems (24). In fact, although direct tropospheric fluorescence HO measurements were first... 

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