Relative fluorescence intensities

Several methods were reported for the analysis of histamine, but the fluorimetric determination with o-phthaldialdehyde (OPA) the most widely used. It was shown that adducts, formed in the reaction of histamine with OPA in the presence of reducing agent, is more stable and gives high relative fluorescence intensity. The influences of different tiols on the fluorimeric determination histamine with OPA have been investigated. 

Table I. Relative Fluorescence Intensities Obtained from Various Types of Nucleic Acids...

Table II. Relative Fluorescence Intensities Obtained Using DNA s from Various Sources...

Csilibrsition. Quantitative binding analysis requires knowing the concentration of FLPEP, which can be determined for a stock solution of FLPEP by absorption spectroscopy. The quenching by the antibody is essentially quantitative, and the relative amounts of free and bound ligand are calculated from the relative fluorescence intensity. 

A study of the relative fluorescence intensities at 460 nm of PET and PET-4,4 -SD yarns after receiving identical irradiation intensities reveals an increase in the formation of the hydroxyterephthaloyl moiety with increasing amounts of 4,4 -SD. This indicates that a photooxidative mechanism involving the second monomer may be an explanation of the increasing degradation rates. 

Fig. 5 Combinatorial synthesis of triazolylcoumarin library using Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction. Each letter represents the relative fluorescence intensities H High, M Middle, L Low. The excitation and emission spectra were recorded in DMF. Reproduced with permission from reference [45]... 

Fluorescence intensity increases with the laser fluence, while its change was quite smooth even around the threshold. If a new process leading to ablation was involved in addition to the Si - Si annihilation, the relative fluorescence intensity of two excimers would not change furthermore above the threshold. Although the details are beyond our current knowledge, we conclude that the Si -Si annihilation is the origin of laser ablation in thiB fluence range. 

Fig. 13 (Left) Emission spectra of PMAA-Ag clusters in the presence of varying concentrations of cysteine from (a) 0 to (r) 60 x 10 6 M. The inset displays the relative fluorescence intensity of Ag clusters recorded at 615 nm vs. the concentration of cysteine. (Right) Fluorescence response of Ag clusters in the presence of various a-amino acids [70]...

Fig. 9.2. Variations in the relative fluorescence intensity as a function of the parameter y according to Eq. (9.31).

After extraction, the urethanated films were subjected to alkaline hydrolysis of urethanes to liberate the corresponding amines, while the adipoylated films were hydrolyzed after having reacted with 7-hydroxycoumarin. Amounts of the released amines and coumarin were determined by fluorescence spectroscopy as described in the Experimental section. Since aniline as well as butylamine has no appreciable fluorescence by themselves, their fluorescence assay was made after reacting with o-phthalaldehyde in the presence of mercaptoethanol. In Figure 3, where relative fluorescence intensities are plotted as a function of concentrations of amines and hydroxycoumarin, one can see that the fluorescence intensities vary linearly with their concentration to permit us the quantitative determination of extremely small amounts of amines and hydroxycoumarin. 

Figure 3. Relative fluorescence intensities of n-butylamine and aniline after reaction with o-phthalaldehyde, a-naphthylamine, and 7-hydroxycoumarin (O) aniline (O) n-butylaminej(A) a-naphthylamine (9) 7-hydroxycoumarin...

Fig. 7. Quenching of the fluorescence of the receptors 10 and 12 on binding the substrate 1, exc = 420 nm, em = 654 nm. Graph top, overlayed fluorescence emission spectra of host 12 with increasing added concentrations of p-carotene 1 graph bottom, relative fluorescence intensities of aqueous solutions of 12 as a function of added p-carotene concentration. was...

As expected [2-4], when the solid and liquid cement components were mixed, the anthracene-toluidine complex fluorescence increased in intensity over time as the cure proceeded and nonfluorescence pathways for energy disposal were blocked. Although the change in peak shape made it difficult to comment on the relative fluorescence intensity from the exciplex compared to that from independent molecules, it was clear that the exciplex... 

Figure 5. Relative fluorescence intensities at 11 K, plotted as ln(I/Io)f of ZnTPP excited at 555 nm vs. acceptor concentration. The acceptors solutions were (a) CBr in BuCl, and for (b), (c), (d),...

Another interesting and recent application of ACE is the fluorescence-enhanced competition assay for the detection of sugar-lectin interactions (77). Because glucose competes with the fluorescently labeled dextran for the lectin-binding sites, the relative fluorescent intensity due to the displaced dextran is proportional to the concentration of glucose. 

Fto. 17. Glancing angle dependence of relative fluorescence intensity of TXRF for each of the contamination situations. Here is the critical angle. (Courtesy of Charles Evans and Associates, Redwood City, CA.)... 

Fig. 5. Courses of predicted and off-line measured cell dry mass concentration and NAD(P)H-dependent relative fluorescence intensity during a high-cell-density cultivation of...

Fig. 12 Dependence of the relative fluorescence intensity fpL on the absorbed pump energy p at Ap = 355 nm for compound 11 in ACN...

Relative fluorescence intensities and spectra at a series of pH values are shown in Fig. 12, and some pertinent parameters are summarized in Table IX. At a specific pH the fluorescence intensity as a function of wavelength has been expressed as relative to the intensity at the maximum at the same pH. The maximum intensities were different at different PH values. Nevertheless, the ratio of intensities of dimer and monomer, ID//M, being independent of polymer concentration, may be compared for all the samples and pH values. 

Decay Time (t) and Relative Fluorescence Intensity (0) of 5Dq 1F2 Transitions at 6100 to 6200 A for EuD3 and its Solid Complexes with Lewis Bases... 

A relative fluorescence intensity scale will be defined in part 1 of the experiment. The cuvette holder should be provided with a water jacket to maintain the temperature within 0.5°. It is recommended that you use the same cuvette for all measurements unless a pair is available that is very well matched. Fluorescence measurements are temperature dependent. It is necessary to maintain all reagents, except the ribonuclease solution, at 37°C, the same as the setting for the cuvette holder in the fluorimeter. 

PTFE polytetrafluoroethylene PUFA polyunsaturated fatty acid PV peroxide value PVDF polyvinylidene difluoride PVP polyvinylpyrrolidone PVPP polyvinylpolypyrolidone RAS retronasal aroma stimulator RDA recommended dietary allowance RF radio frequency RFI relative fluorescence intensity RI retention index RNU relative nitrogen utilization ROESY rotational nuclear Overhauser enhancement spectroscopy RP-HPLC reversed-phase HPLC RPER relative protein efficiency ratio RS resistant starch RT retention time RVP relative vapor pressure S sieman (unit of conductance)... 

Figure 10. Excitation (left) and emission (right) spectra optimized for aleurone tissue showing intensity differences between aleurone, endosperm, and pericarp tissues. The emission monochromator was set at 445 nm for excitation spectral scans and the excitation monochromator was set at 350 nm for emission spectral scans. RFI = relative fluorescence intensity. (From [29])...

Figure 14 Distribution of natural fluorescence in an unstained oat kernel (a) Profile plot of distance (x-axis) Vs relative fluorescence intensity (y-axis) in scan through the mid-point of a kernel cross section, (b) Intensity profile showing fluorescence of phenolic constituents in an oat cross section.

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