Fluorescence quenching is used to gain information on the exposure of tryptophan residues to lipid in membrane-bound proteins and peptides. A protocol is developed to calculate this exposure, based on a comparison of quenching efficiency and of a fluorescence lifetime (or quantum yield) measured for a protein and for a model tryptophan-containing compound. Various methods of analysis of depth-d...

Enhanced reductive fluorescence quenching of meso-tetrakis-5,10,15,20-pentafluorophenyl porphyrin (H2F20TPP) by two different phenols, 4-methoxy phenol (4-MeOPhOH) and 2,6-dimethoxy phenol (2,6-DiMeOPhOH) in the presence of various pyridine bases in dichloromethane solution is studied using steady state and time resolved fluorescence spectroscopic methods by employing time correlated single pho...

mechanical stress and maximum superconducting current have been calculated for a superconductor subjected to uniform plastic deformation. The training effect due to strain hardening o f the material is discussed. These results are compared with an analogous case when the normal transition is caused by the thermo-magnetomechanical instability. The quenching current is shown to depend on the hist...

The interaction of tetrandrine with human serum albumin (HSA) was studied by measuring fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. The fluorescence quenching spectra of HSA in the presence of tetrandrine showed that tetrandrine quenched the fluorescence of HSA. The quenching constants of tetrandrine on HSA were determined using the Stern-Volmer equ...

We consider grain growth and stagnation in polycrystalline microstructures. From the phase-field crystal modeling of the coarsening dynamics, we identify a transition from a grain-growth stagnation upon deep quenching below the melting temperature T(m) to a continuous coarsening at shallower quenching near T(m). The grain evolution is mediated by local grain rotations. In the deep quenching reg...

The nitrophenol derivatives have multiple biological effects and their behaviour in environment is of interest. The fluorescence quenching property can be taken into consideration to understand dinitrophenyl ether toxicity. This study employs fluorescence spectroscopy to characterize the interaction of a model compound for dinitrophenyl ethers, namely 1-allyoxy-2,4-dinitrobenzene with two fluor...

It has long been known that quinones quench chlorophyll fluorescence. This study reports the parameters of the fluorescence quenching of chlorophyll a by 1,4-benzoquinone, in ethanol, using the nonlinear analysis. The fluorescence intensity was measured at 670 nm for the blue and red excitation wavelengths: 430 nm and 650 nm, respectively. The quinone concentration in the samples ranged from 3....

we devote to investigate the quenching phenomenon for a reaction-diffusion system with coupled singular absorption terms, ut Δu − u−p1v−q1 , vt Δv − u−p2v−q2 . The solutions of the system quenches in finite time for any initial data are obtained, and the blow-up of time derivatives at the quenching point is verified. Moreover, under appropriate hypotheses, the criteria to identify the simultane...

Fluorescence quenching of 22 polycyclic aromatic hydrocarbons by nitromethane in toluene and acetonitrile solutions has been studied. Contrary to Sawicki's observations that the fluorescence of hydrocarbons with the fluoranthene skeleton is not quenched that of 11J2and 3.4-benzofluoranthene and fluoranthene itself is quenched. These compounds have a high energy of the fluorescence transition. T...

Luminescence quenching of [Ru(diphenyl-bpr)3]Cl2 and of [Ru(diphenyl-phen)3]Cl2 by 19 transition metal complexes is reported. These complexes have properties which permit them to supplement the widely used [Ru9bpy)3] 2+ and [Ru(phen)3] 2+ sensitizers. The excited state of these complexes can also be tuned significantly by solvent variation. Quenching is predominantly by diffusion. Decay times, ...