Human plasma apolipoprotein A-I (apoA-I) and apolipoprotein C-I (apoC-I) were investigated by time-resolved fluorescence decay and depolarization. The tryptophyl fluorescence of apoAI undergoes a double-exponential decay with lifetimes of 1.07 and 3.43 ns which remain unchangcd over the range of apoA-I concentration studied. The time-resolved fluorescence of both native and denatured forms of a...

Hydrodynamic properties as well as structural dynamics of proteins can be investigated by the well-established experimental method of fluorescence anisotropy decay. Successful use of this method depends on determination of the correct kinetic model, the extent of cross-correlation between parameters in the fitting function, and differences between the timescales of the depolarizing motions and ...

Phase-sensitive flow cytometry (PSFC) is a technique in which fluorescence excited state decay times are measured as fluorescently labeled cells rapidly transit a finely focused, frequency-modulated laser beam. With PSFC the fluorescence lifetime is taken as a cytometric parameter to differentiate intracellular events that are challenging to distinguish with standard flow cytometry. For example...

a rapid and sensitive hplc method has been developed for the quantification of mirtazapine (mrz), a noradrenergic and specific serotonergic inhibitor antidepressant (nassa) and its two major metabolites n-desmethylmirtazapine (ndm) and 8-hydroxymirtazapine (8-ohm) in human plasma. the separation was achieved using chromolith c18 column and a mobile phase of acetonitrile: phosphate buffer (ph=3,...

the aggregation behavior of anionic cobalt(ii) 4,4′,4ʺ,4‴-tetrasulfonated phthalocyanine, [co(tspc)4-] was studied at its various concentrations and different ionic strengths using optical absorption and resonance light scattering (rls) spectroscopies in 5 mm phosphate buffer, ph 7.0 at 25 °c. the results show no aggregation behavior at concentration range of 5.1 × 10-6-7.5 × 10-5 m. also, the ...

The solvatochromic and electrochemical properties of electronic push-pull 2-aminobithiophenes consisting of an aldehyde and nitro withdrawing groups were examined. With the use of an integrating sphere, the absolute quantum yields of the bithiophenes were measured. They were found to be highly fluorescent (Φfl > 70%), provided the nitro group was not located in the 4'-position. High fluorescenc...

pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B)...

Solar-induced chlorophyll fluorescence (SIF) has been used as an indicator for the photosynthetic activity of vegetation at regional and global scales. Canopy structure affects radiative transfer process SIF within canopy causes angular-dependencies SIF. A common solution interpreting these effects is use physically-based models. As a first step, comprehensive evaluation three-dimensional (3D) ...

(1) Background: Biophysical techniques applied to serum samples characterization could promote the development of new diagnostic tools. Fluorescence spectroscopy has been previously biological from cancer patients and differences healthy individuals were observed. Dendronized hyperbranched polymers (DHP) based on bis(hydroxymethyl)propionic acid (bis-MPA) developed in our group their potential ...