Fluoresence

Shera E B, Seitzinger N K, Davis L M, Keller R A and Soper S A 1990 Deteotion of single fluoreseent moleoules Chem. Phys. Lett. 174 553-7... 

Added eost is very important in this area sinee power faetor eorreetion is an unseen benefit to the eustomer who does not want to pay for anything he or she eannot direetly see. An example is PFC eorreeted, eleetronie fluoreseent light-... 

In X-ray fluoreseenee ineident radiation induees eleetronie fluoreseent emission in most atoms. The effeets ean be used both qualitatively and quantitatively for metals, alloys ete. 

Some commercial spectrophotometers have fluorescence attachments which allow the sample to be irradiated from an ancillary source and the resulting fluoresence to pass through the monochromator for spectral analysis. 

J R Lakowicz, Principles of Fluoresence Spectroscopy, Plenum, New York, 1983... 

Ellis DW (1979) Analysis of aromatic compounds in water using fluoresence and phosphorescence. PB report no. 212268. National Technical Information Service, Springfield, VA, USA... 

Sulfur oxyanions are similar to nitrate and nitrite in that they are mobile in soil and can be converted to many different forms (see Chapter 4, Figure 4.8). However, they are different from the other oxyanions in that they are the source of the essential nutrient, sulfur, and are deposited on soil from the atmosphere. Sulfate species can be determined by X-ray fluoresence (XRF), making their determination easier than the other oxyanions [21,22], Sulfur is discussed in more detail in Section 6.2.23. 

The fluoresence lifetimes calculated for TIN in low viscosity alcohols are approximately proportional to the solvent viscosity (12) which suggests that in these solvents there is a non-radiative process related to. the rotational diffusion mobility of the TIN molecule. The observed extent of the quenching, however, is significantly greater than that expected due to viscosity effects alone and cannot be explained by a collisionally-induced, Stern-Volmer type process involving methanol molecules (25.) as the appropriate plot is non-linear. 

Introduction of an additional phenyl ring in the SNAFL structure leads to carboxynaphthofluorescein (CNF), whose absorption and fluoresence spectra are further red-shifted. CNF has a pKa of 7.5 and can be used in either excitation or emission ratiometric measurements. 

Figure 1.5. Noninvasive sensing of glucose. Within the optical window (650 nm-1300 nm), lifetime-based sensing by fluoresence is possible through the human skin.

L. Bokobza, C. Pham-Van-Cang, C. Giordano, L. Monnerie, J. Vandendriessche, and F. C. De Schryver, Studies of the mobility of probes in polypropylene oxide) 2. Excimer fluoresence technique, Polymer 29, 251 (1988). 

E. Pajot-Augy, L. Bokobza, L. Monnerie, A. Castallan, and H. Bouas-Laurent, Mobility of macro-molecular chains as studied by means of excimer fluoresence, Macromolecules 17, 1490 (1984). 

B. Strehmel, V. Strehmel, H. J. Timpe, and K. Urban, Time-resolved fluoresence measurements for the characterization of epoxy systems, Eur. Polym. J. 28, 525-533 (1992). 

R. O. Loutfy, Fluoresence probes for polymer free-volume, Pure AppL Chem. 58, 1239 (1986). 

S. Tazuke, R. K. Guo, and T. Ikeda, Time-resolved fluoresence spectroscopy of a twisted intramolecular charge transfer compound bonded to polymers, /. Phys. Chem. 94, 1408(1990). 

Regarding the study of these complexes by various physical techniques, only IR spectroscopy has been widely used so far. Only a few X-ray structural, electronic absorption, and fluoresence emission spectral data are available. Other methods such as ESR (especially of Gd(III) complexes), NQR, and Mossbauer (especially of Eu-151) have not been seriously applied for the study of these complexes in the solid state. In solution, only conductance studies have attracted attention NMR, dipole moment, and electronic spectral studies are few in number. The lack of physical data limits our understanding of the structure and bonding in these complexes. In future, when more interest is evinced in applying various physical techniques to study these complexes, one may hope to come across more interesting and useful revelations. 

E.L. Wehry, Applications of Fluoresence and phosphoresence techniques in environmental analysis, in Practical Fluorescence, G.G. Guilbault (Ed), Marcel Dekker, New York, 1999. 

The long-term production of indole alkaloids by high-yielding strains of C. roseus has been examined by Deus-Neumann and Zenk 148). Serpentine (40), which exhibits a bright blue fluoresence, was chosen as the alkaloid to monitor, and the level of this compound was followed in six cell... 

Dividing cells in culture exposed to vinblastine or vincristine are arrested from further growth during mitosis (12,13). In fact, the antimitotic effects of this class of compounds is ubiquitous. These effects are observed at relatively low concentrations (<1 iM), and are reversible when drug is removed from the media prior to lysis of the arrested cells. The concentration of drug required to elicit an antimitotic effect is usually comparable to that required to produce a cytotoxic effect in the same cell type (14,15). Originally, this type of analysis was exceedingly laborious, but the introduction of laser- and computer-based fluoresence activated cell sorters (FACS) has rendered this type of analysis routine. Nevertheless, a cytotoxic, non-cell cycle-specific bisindole alkaloid has yet to be discovered. 

In-Situ-Fluoresence-Probes A Useful Tool for Non-invasive Bioprocess Monitoring... 

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