the interaction between propranolol (prop) and human serum albumin (hsa) was studied in the presence of dimethyl methylphosphonate (dmmp). dmmp is usually considered as a simulant for chemical warfare agents (cwas). for this purpose fluorescence quenching, resonance light scattering (rls), synchronous, three-dimensional fluorescence spectroscopy and molecular dynamics (md) simulation were emplo...

Depth-dependent fluorescence quenching in membranes is playing an increasingly important role in the determination of the low resolution structure of membrane proteins. This paper presents a graphical way of visualizing membrane quenching caused by lipid-attached bromines or spin labels with the help of a depth-dependent fluorescence quenching profile. Two methods are presently available to ext...

A novel technique is described that uses either time-resolved or steady state prompt photosensitizer fluorescence to measure local oxygen concentration. Solution experiments conducted with Al(III) phthalocyanine chloride tetrasulfonic acid confirmed that the steady state fluorescence signal is dependent on the oxygen concentration and fluence rate. A relationship between prompt sensitizer fluor...

We characterized the dissociation of polymer/DNA polyplexes designed for gene delivery using water-soluble quantum dots (QDs). A pH-responsive pentablock copolymer was designed to form stable complexes with plasmid DNA via tertiary amine segments. Dissociation of the polyplex was induced using chloroquine where the efficiency of this process was sensed through changes in QD fluorescence. We fou...

Under excess illumination, the Photosystem II light-harvesting antenna of higher plants has the ability to switch into an efficient photoprotective mode, allowing safe dissipation of excitation energy into heat. In this study, we show induction of the energy dissipation state, monitored by chlorophyll fluorescence quenching, in the isolated major light-harvesting complex (LHCII) incorporated in...

The pathways of energy dissipation of excessive absorbed energy in cyanobacteria in comparison with that in higher plants are discussed. Two mechanisms of non-photochemical quenching in cyanobacteria are described. In one case this quenching occurs as light-induced decrease of the fluorescence yield of long-wavelength chlorophylls of the photosystem I trimers induced by inactive reaction center...

We prove that stimulated emission is by far the dominant quenching mechanism for providing super-resolution in fluorescence microscopy with a red-shifted depletion beam. Our evidences are based on simultaneously measuring fluorescence quenching and photon gain in the quenching beam. Measurements were performed for several fluorescent dyes including fluorescent proteins over a wide spectral rang...

KO E H N, A.C. (Alabama A&M University, Normal, AL 35762) AND R.L. DOUDRICK (Southern Institute of Forest Genetics, Saucier, MS 39574). Diurnal patterns of chlorophyll fluorescence and CO, fixation in orchard grown Torreya ta.n’jdiu (Am.). Bull. Torrey Bot. Sot. 126:93398. 1999.-Chlorophyll fluorescence and CO, fixation measurements were taken on sunny days in October, 1996, on three Torreyu ta...