0.2 MeV中子照射洋葱萌发种子后根尖细胞微核诱发率的研究

目的 了解单能中子的相对生物效应。方法 通过由Schenkel型加速器产生的0.2 MeV单能中子以及⁶⁰Co γ射线照射洋葱萌发种子,观察单位剂量的两种辐射在洋葱根尖细胞中微核诱发率的差异。结果 0.2 MeV单能中子单位剂量的微核诱发率为(133.0±6.4)% Gy^-1;⁶⁰Co γ射线单位剂量的微核诱发率为(3.59±0.19)% Gy^-1。以⁶⁰Co γ射线为参考辐射,0.2 MeV单能中子照射洋葱萌发种子后在根尖细胞中诱发微核的相对生物效应(RBE)值为37.0±2.7。结论 以⁶⁰Co γ射线为参考辐射,0.2 MeV单能中子照射洋葱萌发种子后在根尖细胞中诱发微核的RBE值高达37.0±2.7。因此,为更好地解明具有高线能传输(LET)的中子的生物效应机制,以及放射治疗的基础研究提供了一种较好的手段。

Study of the Frequencies of Micronuclei Induced in the Root - tip Cells of Onion Seedlings by 0.2 MeV Neutrons

Objective To best understand the relative biological effectiveness (RBE) of mono-energetic neutrons.Methods To observe the difference of the frequencies of micronuclei induced in the root-tip cells of onion seedlings irradiated by 0.2 MeV mono-energetic neutrons from a Schenkel type accelerator and γ rays from a ⁶⁰Co source.Results The frequencies of micronuclei induced by unit dose of 0.2 MeV mono-energetic neutrons and γ rays from a ⁶⁰Co source are (133.0 ±6.4) and (3.59±0.19)% Gy^-1, respectively.Thus, when a ⁶⁰Co γ-ray source is used as reference radiation, the RBE value for 0.2 MeV mono-energetic neutrons to induce micronuclei in the root-tip cells of onion seedlings is about 37.0±2.7.Conclusions Using a ⁶⁰Co γ-ray source as reference radiation, the RBE value of 0.2 MeV mono-energetic neutrons to induce micronuclei in the root-tip cells of Allium onion seedlings is as high as 37.0 ±2.7.It provides a good method to best understand the mechanism of the biological effectiveness of high LET neutrons, and for the basic study of radiation therapy.