Department of Physics, Shiraz University, Shiraz, Iran.
Department of Physics, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran.
Int J Radiat Biol. 2020 Jun;96(6):767-778. doi: 10.1080/09553002.2020.1730015. Epub 2020 Feb 25.
Interaction of ionizing radiations with cells leads to single- and double-strand breaks (SSBs and DSBs) as well as base lesions of DNA. Employing the Geant4-DNA toolkit, we simulated the transportation of primary alphas and secondary particles in liquid water to study the damage in the form of SSBs and DSBs. Simulations were performed in a spherical water medium, where we used a B-DNA model and classified the DNA damage and its complexity. We assumed that in a certain vicinity of the DNA volume, energy depositions of more than 17.5 eV or hydroxyl radicals with a chemical-reaction probability of 0.13 would lead to strand breaks. The results of 2 to 20 MeV alpha particles showed that more than 65% of the energy-deposition cases within the DNA volume would result in a form of break. The frequency pattern of higher-complexity damage types appeared to peak at higher deposited energies. We observed a reasonable agreement in terms of trend and value between our DSB yield results and experimental data. The yield results, as function of LET, suggested independence from particle type and converge to some extent at large LET. This manifests the dominant contribution of secondary electrons.
电离辐射与细胞相互作用会导致单链和双链断裂（SSBs 和 DSBs）以及 DNA 的碱基损伤。我们使用 Geant4-DNA 工具包模拟了初级阿尔法粒子和次级粒子在液态水中的输运，以研究 SSBs 和 DSBs 形式的损伤。模拟在球形水介质中进行，我们使用 B-DNA 模型并对 DNA 损伤及其复杂性进行分类。我们假设在 DNA 体积的某个附近，如果能量沉积超过 17.5 eV 或具有 0.13 的化学反应概率的羟基自由基，则会导致链断裂。2 至 20 MeV 阿尔法粒子的结果表明，在 DNA 体积内超过 65%的能量沉积情况将导致某种形式的断裂。较高复杂性损伤类型的频率模式似乎在较高沉积能量处达到峰值。我们观察到我们的 DSB 产额结果与实验数据在趋势和数值上具有合理的一致性。作为 LET 函数的产额结果表明，粒子类型的独立性以及在较大 LET 下的某种程度的收敛。这表明二次电子的主要贡献。
