【摘要】 为了解决低传能线密度辐射诱发的染色体畸变存在剂量率效应的问题,以便较为准确地估算不同剂量率受照人员的吸收剂量。用3种不同照射剂量率的低剂量X线照射离体人外周血,CA诱导染色体早熟,收获早熟凝集染色体,采用盲法阅片,计数染色体断片数和畸变细胞数,分析畸变率与照射剂量之间的关系,分别拟合不同剂量率的剂量效应曲线和数学模型。结果表明,在剂量率一定的情况下,各剂量点的染色体断片率随吸收剂量增加而增加。同一剂量点不同剂量率射线诱发的染色体断片率随剂量率的增加而增加,剂量率效应明显。因此在估算低传能线密度辐射的吸收剂量时,应该考虑剂量率效应,根据受照情况尽量选择剂量率相近的剂量-效应关系曲线进行估算,从而使结果更为准确。更多还原

【Abstract】 There is a dose-rate effect between the chromosome aberrations and ionizing radiation in the low Linear Energy Transfer. To better estimate the biological dose absorbed under different dose rates,human peripheral blood was irradiated by X-rays in three different irradiation dose rates. CA was used to induce premature chromosome condensation,and then counted the chromosome fragments rate of the specimens by blind reading. To analyze the relationship between chromosome aberration rate and irradiation,we established the dose- response curves and mathematical model in different dose rates.Results show the aberration frequency increases with the absorbed dose when the dose rate is constant;and the aberration frequency increased with dose rate wthen the absorbed doses are the same. There is a notable dose-rate effect observed. Considering the dose-rate effect,approximate dose-rate dose- response curve should be chosen to estimate the absorbed dose in low linear energy transfer.更多还原