Preparation, characterization, thermal studies, photochemical behaviours and antimicrobial activity of complexes derived from 5-methyl-3-furaldehyde thiosemicarbazone and HG[II] salts of hallo acids

Complexes from of 5-methyl-3-furaldehydethiosemicarbazone [5M3HFTSC] and Hg[II] salts derived from inorganic [HCl] and organic hallo acids [CHCl2COOH or CF3COOH] have been prepared. There chemical structures were characterized using elemental analyses, conductivity spectral measurements, thermogravimetric methods and photochemical behaviours. The thermal studies of such complexes using thermogravimetric analysis [TGA], derivatives thermogravimetry [DrTG] from ambient temperature to 750°C showed three decomposition steps. These studies indicated that the thermal decompositions are not simples. The photolysis of the studied compounds has been carried out in the presence of H2O2. It was found that, the photolysis was enhanced in the presence of H2O2 due to the generation of .OH radicals which are very strong oxidizing agent. Biological activity of theses compounds was tested and screened for their in-vitro antibacterial and antifungal activity. The mixed ligand complexes generally are more active than the binary and free thiosemicarbazne ligand

Phenylthiourea derivatives as organic stabilizer for polystyrene against photodegradation

N-phenylthiourea derivatives have been prepared and investigated as photostabilizers for polystyrene by measuring the extent of weight loss [%], the amount of formed gel as well as the average molecular weights of the soluble fractions [M[v]] of the degraded polymers. The results indicated a reasonable stabilizing effect of these derivatives compared with phenyl salicylate UV-absorber. A synergistic effect is achieved when the investigated stabilizers are mixed with the phenyl salicylate in a weight ratio of 25% of the thiourea derivative and 75% of the reference stabilizer. A probable radical mechanism is proposed to account for the stabilizing action of the organic investigated materials

Photo-onycholysis induced by doxycycline: a new clinical feature

Photo-onycholysis is a rare complication of tetracyclines. Three clinical subtypes are usually reported. In type I, several nails are often involved and the separated portion of the nail is half-moon-shaped with proximal convexity. In type II, only one nail is involved and there is a proximal notch due to the concentration of ultraviolet rays. Type III is medio-ungueal, away from distal end and lateral folds of the nail. We report a new form of photo-onycholysis induced by doxycycline resembling the latter subtype. In fact there is no involvement of the distal or disto-lateral end of the nail but the separation of the nail starts from the proximal fold. As far as we know, such a clinical feature has not been reported before