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DNA组分损伤研究是低能离子辐照机理研究的一个重要领域。研究发现,受离子束辐照的胸腺嘧啶(T)样品的紫外差光谱具有两个正的吸收峰,分析认为这是由于嘧啶环π电子共扼结构变化的结果;而其残余紫外活性几乎不受酸、碱处理的影响。另外,测量了脱氧胸腺嘧啶核苷(dTR)及其核苷酸(5′-dTMP)在强酸、强碱处理前后的残余活性,应用紫外分光光度法研究了受辐照靶分子残余浓度的剂量效应。发现dTR、5′-dTMP辐解产生的T的产率因热处理而增大,但酸、碱的处理将导致辐射产生的T~*-S或T~*-S-P中的T~*裂解,从而使得T的产率减小,如0.1mol/L NaOH处理离子注入后的5′-dTMP可使碱基T的释放量减少一半。另一方面,碱处理离子注入后的5′-dTMP样品可使其无机磷的释放量大大增加,并且增加的程度与碱处理的时间有关,但G(Pi)则随剂量的增加而非线性地减小。
DNA component damage research is an important field of low-energy ion irradiation mechanism. It was found that the UV spectrum of thymine (T) samples irradiated by ion beam had two positive absorption peaks, which was analyzed as a result of the change of the π electron conjugated structure of the pyrimidine ring. However, the residual ultraviolet activity almost did not By the acid and alkali treatment. In addition, the residual activity of dTR and its nucleotide (5’-dTMP) before and after treatment with strong acid and alkali was measured. The dosage of residual concentration of irradiated target molecule was studied by ultraviolet spectrophotometry effect. The dTR was found that the yield of T produced by 5’-dTMP radiolysis increased due to heat treatment, but the treatment of acid and base would result in the cleavage of T * in T ~ * -S or T ~ * -SP by irradiation, As a result, the yield of T is reduced. For example, 0.1 mol / L NaOH treatment of 5’-dTMP after ion implantation can reduce the base T release by half. On the other hand, alkali-treated 5’-dTMP samples significantly increased the release of inorganic phosphorus, and the degree of increase was related to the time of alkali treatment, but G (Pi) was non-linear To reduce.