电子对生物分子DNA损伤可能性的分析

目的研究电子在人体组织等效材料中形成的“簇点”能量分布情况，以及簇点的产生对生物效应发生的意义。方法针对电子与人体组织等效介质作用的物理机理，利用蒙特卡罗(MC)方法，按一个个相互作用事件(电离、激发、弹性散射、Auger电子发射)方式真实模拟电子在介质中的径迹，通过对这些事件进行统计分析，得到相关结论。结果电子在穿过介质过程中，主要以簇点(大于30％)形式沉积能量，并且80％以上的簇点中的能量沉积在50eV以上；簇点的密集程度与电子能量、簇点直径密切相关，簇点中能量沉积也取决于辐射类型和能量。结论簇点中的能量沉积是诱发组织细胞核内DNA分子各种损伤的最主要因素。

The analysis for energy distribution and biological effects of the clusters from electrons in the tissue equivalent material

Objective To study energy distribution of the clusters from electrons in the tissue equivalent material,and discuss the important aspects of these clusters on inducing biological effects. Methods Based on the physical mechanism for electrons interacting with tissue equivalent material,the Monte Carlo(MC) method was used. The electron tracks were lively simulated on an event-by-event (ionization,excitation,elastic scattering,Auger electron emission) basis in the material. The relevant conclusions were drawn from the statistic analysis of these events. Results The electrons will deposit their energy in the form(30%) of cluster in passing through tissue equivalent material,and most clusters (80%) have the energy amount of more than 50 eV. The cluster density depends on its diameter and energy of electrons,and the deposited energy in the cluster depends on the type and energy of radiation. Conclusion The deposited energy in cluster is the most important factor in inducing all sort of lesions on DNA molecules in tissue cells.