ce has become one of the most powerful methods for assessing photosynthetic performance in plant physiological experiments (Horton and Bowyer, 1990; Krause and Weis, 1991). This has resulted almost entirely from the development of methods to distinguish photochemical and nonphotochemical quenching of fluorescence. Moreover, it is now clear that the process of nonphotochemical quenching itself i...

Solid-state self-quenching processes of highly efficient Ir(III) phosphorescent emitters are investigated by the measurement of thin film photoluminescence quantum efficiency and transient lifetime as a function of doping concentration in a host matrix. The radiative decay rate constant is found to be independent from the average distance between dopant molecules (R), and the concentration-quen...

Background Metabolomics, aiming at the quantification of all extracellular and intracellular metabolites, is a valuable tool for characterizing, understanding and manipulating the physiology of mammalian cells. While extracellular metabolite analysis is well established, required quenching and extraction procedures for intracellular metabolite analysis in mammalian suspension cells are not yet ...

     Resonance light scattering (RLS) intensity of silver nanoparticles in the presence of sodium dodecylsulphate was quenched on addition of sulfasalzine. The quenching extent was shown to be proportional to the sulfasalazine concentration. Effect of different parameters such as pH, volume and kind of buffer, silver nanoparticles concentration, sodium dodecylsulphate (SDS) concentration, and w...

N,β-D-glucopyranosyl vincosamide (GPV), a major alkaloid of Psychotria leiocarpa, constitutes up to 2.5% of the dry weight in leaves. Alkaloid content was not elicited by mechanical wounding or jasmonate. At concentrations found in natural conditions or 2.5 fold higher, GPV did not inhibit herbivory in two unrelated generalist models (Helix aspersa and Spodoptera frugiperda) or in a specific in...

The inÛuence of interstitial hydro gen concentration and structural defects caused by quenching of pallad iu m, b egun at di ̃erent temp eratures up to the temp erature of liqui d nitrogen or by stretching by external forces, on spectra of lif etimes of positrons in this metal w as investigated . I t w as found that the spectra of p ositron lif etimes in the examined systems are b est describ ed...

We introduce the first integrated active quenching circuit (I-AQC) that drives an avalanche photodiode (APD) above its breakdown voltage, in order to detect single photons. Based on the I-AQC, we developed a compact and versatile photon-counting module suitable for applications in which very weak optical signals have to be detected, as for instance, photon correlation spectroscopy, luminescence...

Concentration quenching is a major impediment to efficient organic light-emitting devices. We herein report on Organic Light-Emitting Diodes (OLEDs) based on a fluorescent amorphous red-emitting starbust triarylamine molecule (4-di(4’-tert-butylbiphenyl-4-yl)amino4’-dicyanovinylbenzene, named FVIN), exhibiting a very small sensitivity to concentration quenching. OLEDs are fabricated with variou...

Two-dimensional (2D) materials have attracted tremendous interest as fluorescence quenchers of dye-labeled biomolecules for application in biosensing. Metal-organic framework (MOF) nanosheets, as a new type of 2D material, have rarely been studied as bioanalytical platforms. Herein, we synthesize a series of ultrathin lanthanide-based MOF (MOF-Ln) nanosheets as a dye-labeled aptamer platform. T...

Less than 5% of the total pool of free amino acids in plants under stress-free conditions is provided by proline. In many plants under various forms of stress, the concentration increases up to 80% of the amino acid pool. This observation raises the question about the molecular mechanisms, making a high proline concentration favourable under stress conditions. Therefore, the literature about th...