The aim of this study was to quantify the hydroxyl radicals (*OH) produced when aqueous solutions are decomposed by high-linear energy transfer (LET) 290 MeV/nucleon carbon-ion beams using an electron spin resonance (ESR) spectrometer. Aerated cell culture medium containing 200 mM 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was irradiated with doses of 0 to 20 Gy with an LET of 20 to 90 keV/ micro ...

The major radiation-induced degradation products of 5.6-dihy dro thymine (1) in aqueous solutions saturated either with O2 or N2O/O2 (75/25 v/v) were identified as thymine (10), the transand cis-isomers of 6-hydroperoxy-5,6-dihydrothymine (5, 7), 5-hydroperoxy-5,6-dihydrothymine (9), and their corresponding hydroxy derivatives (4, 6, 8). The formation of these compounds is explained in terms of...

The study of the reaction of the hydrated electron with adenosine by optical and dc-conductivity pulse radiolysis on nano- and microsecond timescales has been carried out in an attempt to answer the question whether the electron adduct radical becomes protonated or not. The following conclusions have been reached: (1) the reaction of the hydrated electron with adenosine is followed by a water-m...

Absolute rate constants for the reaction of NADH with thiyl free radicals derived from various sulphur-containing compounds of biological significance were measured by using the technique of pulse radiolysis. These and related reactions with phenoxyl free radicals are believed to occur through one-electron-transfer processes. Further evidence comes from studies with deuterated NADH. The results...

Ionization damage (radiolysis) and knock-on displacement are compared in terms of scattering cross section and stopping power, for thin organic specimens exposed to the electrons in a TEM. Based on stopping power, which includes secondary processes, radiolysis is found to be predominant for all incident energies (10-300 keV), even in materials containing hydrogen. For conducting inorganic speci...