The modifications of the PVA-TiO2 membranes exposed to gamma radiations were investigated by ESR and XRD methods. The ESR spectra show the appearance of a strong signal associated with the breaking of the polymeric chain and the appearance of the unpaired electrons. The mechanism is influenced by the concentration of TiO2. The modification of local order of the polymeric chains after irradiation is confirmed by XRD method

A systematic IR, Raman and ESR study of the P2O5-CdO-Li2O glass system--a possible dosimeter material, is reported. The proportion of P2O5 remains constant at 0.5 mol% and those of CdO and Li2O are changed from 0 to 0.5 mol%. IR and Raman spectra allowed us to identify the structural units which appear in the structural network of these phosphate glasses and also the network modifier role of Cd2+ and Li+ ions. Generally, a local network structure

Reported here are the production, purification and characterization of a laccase from the phytophathogenic fungus Sclerotinia sclerotiorum. This laccase is identified by mass spectrometry with a sequence coverage of 74.9% (458/577 AA) revealing that the protein is identical or highly homologous to a predicted oxidoreductase from this species (A7EM18 in the Uniprot database); the closest homologous protein previously isolated from a fungus is the

Chemical reduction of an iron(III) substituted Dawson 5-molybdo-12-tungsto-2-phosphate a2-K7[Fe(H2O)P2Mo5W12O61]·17H2O complex, with dithionite in aqueous solution is reported alongside with similar data for the monolacunary Dawson molybdo-tungsto diphosphates a2-[P2Mo5W12O61]10-. UV-vis absorption and lowtemperature EPR (electron paramagnetic resonance) spectra indicate several distinct species and an unprecedented change of spin state at the ferric

Copper porphyrinates are generally known to display a less diverse reactivity compared to their iron counterparts. Here, we examine a water-soluble copper porphyrinate for its ability to engage in reactions involving axial ligation to the copper or possible redox cycling. Although UV-vis spectra indicate an expected lack of reactivity, electron paramagnetic resonance spectra (EPR) reveal an unexpected wealth of changes in electronic structures at

Electron Paramagnetic Resonance (EPR) spectroscopy and the spin trapping technique were employed in order to monitor the superoxide radical liberated from potassium superoxide in aqueous alkaline solutions; DEPMPO (5-diethoxyphosphoryl-5-methyl- 1-pyrroline-N-oxide) was used as a trapping agent. Three reaction systems were prepared, varying the ratios between KO2, superoxide and DEPMPO. The data indicate distinct mechanisms leading to DEPMPO/spin

Authenticity has probably always been a major concern of many consumers and it is still gaining more and more importance. In our study we used two analytical methods to characterize antioxidant activity and to evaluate the authenticity of juices; isotope ratio mass spectrometer(IRMS) and Electron Paramagnetic resonance (EPR). Isotope ratio mass spectrometry is a promising tool for origin assignation of food, thus 13C, 18O and 2H measurements are

During polymerization of dimethacrylate monomers employed in dental materials, the gel effect leads to entrapment of radicals and unreacted monomers in the crosslinked network, affecting physico-mechanical properties and the biocompatibility. Reported here is a study of the effect of the resin composition, irradiation time and storage time of some new light-cured dental composites upon the free propagating radical concentration, using Electron Spin

Antioxidant status of foods, plant, or fruit products is generally characterized by means of spectroscopic methods. Methods like HPLC, UV-VIS, or MS spectroscopy are used to understand the chemical and physical properties of different samples, and also EPR spectroscopy seems to be a valuable tool to characterize antioxidant activity of juice beverages. In this technique, certain antioxidants present in fruit juices interact with free radicals interrupting

We have previously reported that derivatization of hemoglobin with periodate-modified sugar derivatives such as oxidized adenosine triphosphate (oATP) leads to an increase in prooxidant reactivity at the heme. Here, we report that copolymerization of hemoglobin with serum albumin alleviates this problem completely, to the extent where the copolymer even has a slightly lower autooxidation rate compared to native hemoglobin. A similar, although not