title: Heavy-ion-induced free radical formation in solid DNA-constituents: quantitative and structural aspects.
abstract: Electron spin resonance (ESR) spectroscopy was used to study free radical formation in solid, polycrystalline pellets of DNA-constituents. Dose-yield curves were obtained at low (ca 90 K) and ambient temperatures, and were analyzed for initial G-values (radicals per 100 eV absorbed energy). At both temperatures, values of one or more orders of magnitude below the corresponding x-ray values were found. Combination of x-ray and heavy-ion irradiation indicated an enhanced radical destruction as probable cause of reduced G-values. Structural aspects as analyzed from the ESR-powder spectra revealed differences in initial, low-temperature radical population and in decay reactions upon annealing between heavy-ion bombardment and low-LET irradiation.
authors.affiliation: Fachrichtung Biophysik und Physik Grundlagen der Medizin, Universität des Saarlandes, Homburg/Saar, F.R.G.
authors.forename: J
authors.initials: J
authors.lastname: Hüttermann
authors.forename: A
authors.initials: A
authors.lastname: Schaefer
mesh_terms: D000241:Adenosine / Q000528:radiation effects; D003596:Cytosine / Q000528:radiation effects; D004247:DNA / Q000528:radiation effects*; D003841:Deoxycytidine / Q000528:radiation effects; D003857:Deoxyuridine / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004578:Electron Spin Resonance Spectroscopy; D004735:Energy Transfer; D005609:Free Radicals; D007477:Ions; D010315:Particle Accelerators; D013941:Thymine / Q000528:radiation effects
chemical_list: D005609:Free Radicals; D007477:Ions; D003841:Deoxycytidine; D003596:Cytosine; D004247:DNA; D000241:Adenosine; D013941:Thymine; D003857:Deoxyuridine