Recently, a very interesting observation relating energy generation to the quenching of the fluorescence of the uncoupler atebrin in isolated chloroplasts has been described by Kraayenhof [ 11. It was shown that the required energy could be provided by electron transport, ATP hydrolysis or a pH gradient, and it was therefore suggested that the extent of quenching may be used to measure the ‘ene...

In the present work the effect of different concentration of halide quenchers (Cl, Br, I) on 4-methyl-5-ethoxy-7-methoxy coumarin (1) and 4-methyl-5,7-diethoxy coumarin (2) in aqueous solutions have been carried out at 20 temperature. It was observed that the fluorescence intensity of these coumarin derivatives decrease with increase in the concentration of the quenchers except Cl quencher. Fur...

The photosynthetic apparatus in plants is protected against oxidative damage by processes that dissipate excess absorbed light energy as heat within the light-harvesting complexes. This dissipation of excitation energy is measured as nonphotochemical quenching of chlorophyll fluorescence. Nonphotochemical quenching depends primarily on the [delta]pH that is generated by photosynthetic electron ...

With the emergence of antibiotic-resistant strains of bacteria, the available options for treating bacterial infections have become very limited, and the search for a novel general antibacterial therapy has received much greater attention. Quorum quenching can be used to control disease in a quorum sensing system by triggering the pathogenic phenotype. The interference with the quorum sensing s...

Recently, enzymatic quorum quenching has proven its potential as an innovative approach for biofouling control in the membrane bioreactor (MBR) for advanced wastewater treatment. However, practical issues on the cost and stability of enzymes are yet to be solved, which requires more effective quorum quenching methods. In this study, a novel quorum quenching strategy, interspecies quorum quenchi...

Spectroscopic investigations reveal the presence of a fast quenching process in erbium-doped aluminum oxide waveguides. We quantify the percentage of quenched ions and make predictions about the amplifier performance. Optical amplifiers; integrated optics materials; fast quenching processes; aluminum oxide

where 00, Z>0, and uq(x) >0, Vx G [—1, Z]. Without loss of generality, we may assume that uq(x) is smooth and bounded above by 1 such that uo(±Z) = 1. Since uo(x) is positive, the local (in time) existence and uniqueness of a classical solution of the problem (1.1)—(1.3) are trivial (see [8]). Many results in quenching, such as single point quenching and profiles, are similar to those b...

Tryptophan-induced quenching of fluorophores (TrIQ) uses intramolecular fluorescence quenching to assess distances in proteins too small (<15 Å) to be easily probed by traditional Forster resonance energy transfer methods. A powerful aspect of TrIQ is its ability to obtain an ultrafast snapshot of a protein conformation, by identifying "static quenching" (contact between the Trp and probe at th...

We have examined the quenching of pyrochlorophyll fluorescence by a series of substituted nitrobenzenes in ethanol-pyridine solution and the effect of fluorescence quenching on the quantum yield of sensitized photoreduction of three of the nitro compounds by hydrazobenzene. All nitro compounds examined are at least moderately good quenchers of fluorescence. There is a good correlation between t...