Fluorescence spectroscopic

From the results of the fluorescence spectroscopic study it is concluded that excitation energy at the lowest excited state of a PDA derivative having a thioester moiety is localized at the thioester group intra- or inter-molecular energy transfer from the conjugated system of the PDA to the thioester moiety must have occurred in the crystalline state to afford a photostable crystal (Hasegawa et al., unpublished data). 

Vaz, W. L. C. and Melo, E. (2001) Fluorescence spectroscopic studies on phase heterogeneity in lipid bilayer membranes./. Fluoresc., 11, 255-271. 

In addition, data obtained from infrared, thermal, and fluorescence spectroscopic studies of the outermost layer of skin, stratum corneum (SC), and its components imply enhancer-improved permeation of solutes through the SC is associated with alterations involving the hydrocarbon chains of the SC lipid components. Data obtained from electron microscopy and x-ray diffraction reveals that the disordering of the lamellar packing is also an important mechanism for increased permeation of drugs induced by penetration enhancers (for a recent review, see Ref. 206). 

Kim, H.-B., Habuchi, S., and Kitamura, N., Dynamic fluorescence spectroscopic study on the microstructures in ion-exchange resin particles, Anal. Chem., 71, 842, 1999. 

FBAs can also be estimated quantitatively by fluorescence spectroscopy, which is much more sensitive than the ultraviolet method but tends to be prone to error and is less convenient to use. Small quantities of impurities may lead to serious distortions of both emission and excitation spectra. Indeed, a comparison of ultraviolet absorption and fluorescence excitation spectra can yield useful information on the purity of an FBA. Different samples of an analytically pure FBA will show identical absorption and excitation spectra. Nevertheless, an on-line fluorescence spectroscopic method of analysis has been developed for the quantitative estimation of FBAs and other fluorescent additives present on a textile substrate. The procedure was demonstrated by measuring the fluorescence intensity at various excitation wavelengths of moving nylon woven fabrics treated with various concentrations of an FBA and an anionic sizing agent. It is possible to detect remarkably small differences in concentrations of the absorbed materials present [67]. 

Mayingcr, B. (2004). Endoscopic fluorescence spectroscopic imaging in the gastrointestinal tract. Gastrointest. Endosc. Clin. N. Am. 14, 487-505, viii-ix. 

Yu H, Xi B, Ma W, Li D, He X. Fluorescence spectroscopic properties of dissolved fulvic acids from salined flavo-aquic soils around Wuliangsuhai in Hetao Irrigation District, China. Soil Sci. Soc. Am. J. 2011 75 1385-1393. 

In the present work, we have examined poly(N-vinylcarbazole) (abbreviated hereafter as PVCz) and pyrene-doped poly(aethyl methacrylate) (PMMA) films by using a tine-resolved fluorescence spectroscopic aethod. Fluorescence spectra and their dynanic behavior of the forner fila were elucidated with a high intensity laser pulse and a streak camera, which nakes it possible to neasure dynaaics just upon laser ablation. This aethod reveals aolecular and electronic aspects of laser ablation phenomena (17). For the latter fila a laser pulse with weak intensity was used for characterizing the ablated and Basked areas. On the basis of these results, we demonstrate a high potential of fluorescence spectroscopy in aolecular studies on laser ablation and consider its mechanism. Experimental... 

The time-resolved fluorescence spectroscopic approach is very fruitful in elucidating electronic and molecular aspects of laser ablation of fluorescent polymers. While a plasma-like emission and fluorescence behavior of ablated radicals have been reported (21,... 

Hering, J., and W. Stumm (1991), "Fluorescence Spectroscopic Evidence for Surface Complex Formation at the Mineral-Water Interface Elucidation of the Mechanism of Ligand-Promoted Dissolution," Langmuir7, 1567-1570. 

Investigation turned then to chemical and spectroscopic means to obtain the needed mechanistic understanding. Stephenson et al. [17] looked at gas evolution versus exposure, while Pacifici and Straley [18] used UV fluorescence spectroscopy to identify a photo-oxidation product which was later isolated by Valk et al. [19]. In addition, Valk and co-workers [19-21] isolated a number of additional photolysis products by a combination of hydrolysis and chromatography, Marcotte et al. [22] used ESR to look at radicals generated during degradation, and Day and Wiles [23-26] carried out extensive IR and fluorescence spectroscopic investigations on this subject. 

Heinrich, G., and H. Glisten, Fluorescence Spectroscopic Properties of Carcinogenic and Airborne Polynuclear Aromatic Hydrocarbons, in Polynuclear Aromatic Hydrocarbons Chemistry and Biological Effects (A. Bjprseth and A. J. Dennis, Eds.), pp. 983-1003, Battelle Press, Columbus, OH, 1980. 

Wu, C.-H., I. Salmeen, and H. Niki, Fluorescence Spectroscopic Study of Reactions between Gaseous Ozone and Surface-Adsorbed Polycyclic Aromatic Hydrocarbons, Environ. Sci. Tech-noL, 18, 603-607 (1984). 

After completing initial mass spectrometric studies, it was quickly found, much to the authors delight, that sapphyrin 3, when protonated, acts as an efficient receptor and carrier for chloride and fluoride anions (as judged from the U-tube model membrane studies) vide infra Further, using visible absorption and fluorescence spectroscopic analyses, it proved possible to derive a binding constant (K ) of ca. 9.6 X lO for fluoride anion in methanol. For comparison, chloride anion was found to be bound with much lower affinity in this same solvent (K 10 M ), whereas bromide anion hardly formed a complex at all < 10 M ). 

The above process is well recorded in element partitioning in trapiche ruby. Figure 13.4 shows the summarized results of micro-area XRF (X-ray fluorescence spectroscopic analysis) [3]. The partitioning of Cr, Fe, and Ti in corundum in the core portion, the dendritic portion, and the growth sectors is indicated. The following points should be noted. 

Both proposed two-color experiments have not yet been performed for problems of internal twisting therefore, from the experimental viewpoint, this contribution is confined mainly to fluorescence spectroscopic results, that is, quantum yields, spectral quanta distribution, polarization, and rise and decay functions. 

Kajii, H., et al. 1986. Effects of salicylic acid on the permeability of the plasma membrane of the small intestine of the rat A fluorescence spectroscopic approach to elucidate the mechanism of promoted drug absorption. J Pharm Sci 75 475. 

Chen, I, LeBoeuf, E. I, Dai, S., and Gu, B. (2003). Fluorescence spectroscopic studies of natural organic matter fractions. Chemosphere 50, 639-647. 

D-Fluorescence spectroscopic analysis has also been used for analysis of terrestrial and aquatic HS. Figure 16.40 shows an example of topographic and contour plot of 3D-fluorescence spectrum. In this case, the Fluorescence spectroscopy involved scanning and recording 17 individual emission spectra (260-700 nm) at sequential 10-nm increments of excitation wavelength between 250 and 410 nm (Parlanti et al., 2002). The authors used this technique to obtain structural information about HS and also used it in studies concerning their transformation processes. They reported that there were five major fluorescent components in bulk seawater based on 3D-fluorescence spectroscopy. They defined a and a (excitation at 330-350 nm and emission at 420-480 nm excitation at 250-260 nm and emission at... 

Lang, K., Rieder, R., and Micura, R. (2007). Ligand-induced folding of the thiM TPP riboswitch investigated by a structure-based fluorescence spectroscopic approach. Nucleic Acids Res. 35, 5370-5378. 

Kim, H., Ueno, K., Chiba, M., Kogi, O., Nobom, K., Spatially-resolved fluorescence spectroscopic study on tiquid/tiquid extraction processes in polymer microchannels. Anal. Sci. 2000, 16, 871. 

Khan, M.J., Joginadha Swamy, M., Krishna Sastry, M.V., Umadevi Sajjan, S., Patanjali, S.R., Rao, P., Swarnalatha, G.V., Banerjee, P. and Surolia, A. (1988). Saccharide binding to three Gal/GalNac specific lectins Fluorescence, spectroscopic and stopped-flow kinetic studies. Glycoconjugate Journal, 5, 75-84. 

Simenov, A. et al. 2008. Fluorescence spectroscopic profiling of compound libraries. J. Med. Chem. 51, 2363-2371. 

Deepa, S., Mishra, A.K. (2005). Fluorescence spectroscopic study of serum albumin-bromadiolone interaction fluorimeteric determination of bromadiolone. J. Pharm. Biomed. Anal. 38(3) 556-63. 

Matayosi, E. D. and Kleinfeld, A. M. Emission wavelength-dejjendent decay of the 9-anthroyloxy-fatty acids membrane probes. Biophys. J. 55 215-235, 1981. Garrison, L. M. Doh, L. A. R. M. Pechtold, R. O. Potts, and W. Abraham. Fluorescence spectroscopic evaluation of stratum comeum lipids and related model systems. In K. R. Brain, V. J. James, and K. A. Walters (eds.), Predictions of Percutaneous Penetration, I.B.C. Technical Services Ltd., London, 1993, pp. 1-7. 

Kindzelskii, A. and Petty, H. R. (2004). Fluorescence spectroscopic detection of mitochondrial flavoprotein redox oscillations and transient reduction of the NADPH oxidase-associated flavoprotein in leukocytes European Biophysics Journal with Biophysics Letters 33 291-299. 

Simeonov A, Jadhav A, Thomas CJ, Wang Y, Huang R, Southall NT, Shinn P, Smith J, Austin CP, Auld DS, Inglese J. Fluorescence spectroscopic profiling of compound libraries. J. Med. Chem. 2008 51 2363-2371. 

Doppler-free and Doppler-limited fluorescence spectroscopic studies of the He Is2p-ls3d transitions Calculation of electron excitation rate constants for formation of He(ls2s, - S) and He(ls2p, - p ) using evaluated experimental and theoretical data... 

Photocycloreversions have been reported in 1,2,3,4-tetraphenylcyclo-butane and in the endoperoxide of 1,4,9,10-tetraphenylanthracene, and fluorescence spectroscopic studies have shown that cycloreversion of cis- and trtms-acenaphthylene dimers (178) to acenaphthylene proceeds by way of the excited singlet state. 

---