Hunniford C A, Timson D J, Davies R J H, McCullough R W
Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK.
Phys Med Biol. 2007 Jul 7;52(13):3729-40. doi: 10.1088/0031-9155/52/13/005. Epub 2007 May 25.
The damage induced in supercoiled plasmid DNA molecules by 1-6 keV carbon ions has been investigated as a function of ion exposure, energy and charge state. The production of short linear fragments through multiple double strand breaks has been demonstrated and exponential exposure responses for each of the topoisomers have been found. The cross section for the loss of supercoiling was calculated to be (2.2 +/- 0.5) x 10(-14) cm(2) for 2 keV C(+) ions. For singly charged carbon ions, increased damage was observed with increasing ion energy. In the case of 2 keV doubly charged ions, the damage was greater than for singly charged ions of the same energy. These observations demonstrate that ion induced damage is a function of both the kinetic and potential energies of the ion.
已研究了1-6 keV碳离子对超螺旋质粒DNA分子造成的损伤与离子暴露、能量和电荷态之间的关系。通过多个双链断裂产生短线性片段的现象已得到证实，并且发现每种拓扑异构体的暴露响应呈指数关系。对于2 keV C(+)离子，超螺旋丧失的截面计算为(2.2 +/- 0.5) x 10(-14) cm(2)。对于单电荷碳离子，随着离子能量增加，观察到损伤增加。在2 keV双电荷离子的情况下，损伤大于相同能量的单电荷离子。这些观察结果表明，离子诱导的损伤是离子动能和势能的函数。
