Diatoms microalgae produce biosilica nanoporous rigid outershells called frustules that exhibit an intricate nanostructured pore pattern. In this paper two specific Thalassiosira weissflogii culture conditions and size control procedures during the diatoms growth are described. Data from white field and fluorescence microscopy, evaluation of cell densities and cell parameters (k value and R val...

In this paper we proposed to research the biochemical mechanisms of the biocompounds with indolic structure, by investigating their biochemical effects on one very important physico-chemical parameter of the cell membrane, namely the (trans)membrane potential. The aim of the study was the assessment of the membrane depolarizationrepolarization processes induced by some bio-indoles, namely melat...

A spectrofluorimetric method for the determination of paracetamol is presented, based on the oxidation of the analyte to give the fluorophore 2,2'-dihydroxy-5,5'-diacetyldiaminebiphenyl. Sodium hypochlorite was used as an oxidizing reagent and the optimum pH was found to be 10.0 (sodium carbonate-boric acid buffer solution). The linear concentration range of application was 0.1-100.0 micrograms...

An automated assay suitable for estimating urinary oestrogens in pregnant women has been investigated. Fluorimetry was found to have considerable advantages over colorimetry. The fluorimetric assay was simpler, more precise, more sensitive, and eliminated the need for correction for non-specific chromogens; in the assay of oestriol in pregnant women there was no need for correction for non-spec...

Di-2-pyridyl ketone 2-furoylhydrazone (DPFH) has been examined as a sensitive spectrofluorimetric reagent for the determination of gallium. 4 rapid procedure for the fluorimetric determination of th i s ion at the 2-800 ng ml-1 level at pH 3.S4.1 (Aex 395 nm, he, 473 nm) has been established. The detection limit is 2 ng ml-1 and the relative standard deviation is 2.4% (40 p.p.b. of gallium). In...

For the estimation of fenoverine in pure and pharmaceutical preparation a sensitive spectrofluorimetric method was developed. This wass based on the oxidation of fenoverine with cerric ammonium sulphate to produce cerrous ion, whose fluorescence was observed at 376 nm while excited at 261 nm. The calibration graph was linear over the range of 1-10 μg/ml. This is applied successfully for the ass...