title: Calculation on spectrum of direct DNA damage induced by low-energy electrons including dissociative electron attachment.
abstract: In this work, direct DNA damage induced by low-energy electrons (sub-keV) is simulated using a Monte Carlo method. The characteristics of the present simulation are to consider the new mechanism of DNA damage due to dissociative electron attachment (DEA) and to allow determining damage to specific bases (i.e., adenine, thymine, guanine, or cytosine). The electron track structure in liquid water is generated, based on the dielectric response model for describing electron inelastic scattering and on a free-parameter theoretical model and the NIST database for calculating electron elastic scattering. Ionization cross sections of DNA bases are used to generate base radicals, and available DEA cross sections of DNA components are applied for determining DNA-strand breaks and base damage induced by sub-ionization electrons. The electron elastic scattering from DNA components is simulated using cross sections from different theoretical calculations. The resulting yields of various strand breaks and base damage in cellular environment are given. Especially, the contributions of sub-ionization electrons to various strand breaks and base damage are quantitatively presented, and the correlation between complex clustered DNA damage and the corresponding damaged bases is explored. This work shows that the contribution of sub-ionization electrons to strand breaks is substantial, up to about 40-70%, and this contribution is mainly focused on single-strand break. In addition, the base damage induced by sub-ionization electrons contributes to about 20-40% of the total base damage, and there is an evident correlation between single-strand break and damaged base pair A-T.
authors.affiliation: School of Electrical Engineering, Shandong University, Jinan, 250061, Shandong, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: School of Electrical Engineering, Shandong University, Jinan, 250061, Shandong, People's Republic of China. tzy@sdu.edu.cn.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Tan
authors.affiliation: School of Electrical Engineering, Shandong University, Jinan, 250061, Shandong, People's Republic of China.|Electric Power Research Institute of Tianjin Electric Power Corporation, Tianjin, 300384, People's Republic of China.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Centre d'Etudes Nucléaires de Bordeaux Gradignan, Université de Bordeaux, CNRS/IN2P3, BP 120, 33175, Gradignan, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Champion
mesh_terms: D004249:DNA Damage; D004277:DNA, Single-Stranded / Q000528:radiation effects; D004583:Electrons / Q000009:adverse effects*; D009010:Monte Carlo Method
chemical_list: D004277:DNA, Single-Stranded
keywords: DNA damage spectrum; Direct DNA damage; Dissociative electron attachment; Sub-ionization electron