Physics and Radiobiology of Nuclear Medicine

232 15. Radiation Biology

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Fig. 15.6. Illustration of radiation effects on DNA molecules:(A)Normal DNA
molecule;(B)hydrogen bond is broken without the loss of the base;(C)hydrogen
bond is broken with the loss of the base Τ;(D)single strand break that can repair;
(E)double strand breaks which are well separated and can repair;(F)double strand
breaks that are too close to repair.