title: DNA strand breaks induced by electrons simulated with Nanodosimetry Monte Carlo Simulation Code: NASIC.
abstract: The method of Monte Carlo simulation is a powerful tool to investigate the details of radiation biological damage at the molecular level. In this paper, a Monte Carlo code called NASIC (Nanodosimetry Monte Carlo Simulation Code) was developed. It includes physical module, pre-chemical module, chemical module, geometric module and DNA damage module. The physical module can simulate physical tracks of low-energy electrons in the liquid water event-by-event. More than one set of inelastic cross sections were calculated by applying the dielectric function method of Emfietzoglou's optical-data treatments, with different optical data sets and dispersion models. In the pre-chemical module, the ionised and excited water molecules undergo dissociation processes. In the chemical module, the produced radiolytic chemical species diffuse and react. In the geometric module, an atomic model of 46 chromatin fibres in a spherical nucleus of human lymphocyte was established. In the DNA damage module, the direct damages induced by the energy depositions of the electrons and the indirect damages induced by the radiolytic chemical species were calculated. The parameters should be adjusted to make the simulation results be agreed with the experimental results. In this paper, the influence study of the inelastic cross sections and vibrational excitation reaction on the parameters and the DNA strand break yields were studied. Further work of NASIC is underway.
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China.
authors.forename: Junli
authors.initials: J
authors.lastname: Li
authors.affiliation: Joint Institute of Tsinghua University and Nuctech Company Limited, Beijing, China lichunyan-06@tsinghua.org.cn.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Qiu
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China.
authors.forename: Congchong
authors.initials: C
authors.lastname: Yan
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China.
authors.forename: Wenzhang
authors.initials: W
authors.lastname: Xie
authors.affiliation: Joint Institute of Tsinghua University and Nuctech Company Limited, Beijing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taipei, Taiwan.
authors.forename: Chuanjong
authors.initials: C
authors.lastname: Tung
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D006801:Humans; D008956:Models, Chemical; D009010:Monte Carlo Method; D036103:Nanotechnology / Q000379:methods*; D011874:Radiometry / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D004247:DNA