TY  - JOUR
A1  - Hahn, Marc Benjamin
A1  - Meyer, Susann
A1  - Kunte, Hans-Jorg
A1  - Solomun, Tihomir
A1  - Sturm, Heinz
T1  - Measurements and simulations of microscopic damage to DNA in water by 30 keV electrons: A general approach applicable to other radiation sources and biological targets
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - The determination of the microscopic dose-damage relationship for DNA in an aqueous environment is of a fundamental interest for dosimetry and applications in radiation therapy and protection. We combine GEANT4 particle-scattering simulations in water with calculations concerning the movement of biomolecules to obtain the energy deposit in the biologically relevant nanoscopic volume. We juxtaposition these results to the experimentally determined damage to obtain the dose-damage relationship at a molecular level. This approach is tested for an experimentally challenging system concerning the direct irradiation of plasmid DNA (pUC19) in water with electrons as primary particles. Here a microscopic target model for the plasmid DNA based on the relation of lineal energy and radiation quality is used to calculate the effective target volume. It was found that on average fewer than two ionizations within a 7.5-nm radius around the sugar-phosphate backbone are sufficient to cause a single strand break, with a corresponding median lethal energy deposit being E-1/2 = 6 +/- 4 eV. The presented method is applicable for ionizing radiation (e.g.,.gamma rays, x rays, and electrons) and a variety of targets, such as DNA, proteins, or cells.
Y1  - 2017
U6  - https://doi.org/10.1103/PhysRevE.95.052419
SN  - 2470-0045
SN  - 2470-0053
VL  - 95
PB  - American Physical Society
CY  - College Park
ER  -