An investigation on the radiation sensitivity of DNA conformations to ⁶⁰Co gamma rays by using Geant4 toolkit

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• 作者：F. Semsarha^a ; B. Goliaei^a ; ^{goliaei@ibb.ut.ac.ir" class="auth_mail} ; G. Raisali^b ; H. Khalafi^b ; L. Mirzakhanian^c
• 关键词：Geant4 ; DNA conformation ; DNA damage ; Microdosimetric quantities ; Radiation sensitivity
• 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 出版年：15 March, 2014
• 年：2014
• 卷：323
• 期：Complete
• 页码：75-81
• 全文大小：768 K

文摘

To investigate the impact of conformational properties of genetic material of living cells on radiation-induced DNA damage, single strand breaks (SSB), double strand breaks (DSB) and some microdosimetric quantities of A, B and Z-DNA conformations caused by ⁶⁰Co gamma rays, have been calculated. Based on a previous B-DNA geometrical model, models of A and Z forms have been developed. Simple 34 base pairs segments of each model repeated in high number and secondary electron spectrum of ⁶⁰Co gamma rays have been simulated in a volume of a typical animal cell nucleus. All simulations in this study have been performed by using the Geant4 (GEometry ANd Tracking 4)-DNA extension of the Geant4 toolkit. The results showed that, B-DNA has the lowest yield of simple strand breaks with 2.23 脳 10^鈭?0 Gy^鈭? Da^鈭? and 1.0 脳 10^鈭?1 Gy^鈭? Da^鈭? for the SSB and DSB damage yield, respectively. The A-DNA has the highest SSB yield with 3.59 脳 10^鈭?0 Gy^鈭? Da^鈭? and the Z-DNA has the highest DSB yields with 1.8 脳 10^鈭?1 Gy^鈭? Da^鈭?. It has been concluded that there is a direct correlation between the hit probability, mean specific imparted energy and SSB yield in each model of DNA. Moreover, there is a direct correlation between the DSB yield and both the mean lineal energy and topological characteristics of each model.