TY - GEN A1 - Hahn, Marc Benjamin T1 - Determination of the Microscopic Dose-Damage Relation for Radiation of different Linear Energy Transfer 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.[1] We juxtaposition these results to the experimentally determined damage to obtain the microscopic 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.[2] 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 E1/2=6±4 eV.[1] The presented method is applicable for ionizing radiation (e.g., γ rays, x rays, and electrons) and a variety of targets, such as DNA, proteins, or cells. [1] Hahn, M. B., Meyer, S., Kunte, H.-J., Solomun, T. & Sturm, H. 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. Phys. Rev. E 95, 052419 (2017). [2] Hahn, M. B. et al. Direct electron irradiation of DNA in a fully aqueous environment. Damage determination in combination with Monte Carlo simulations. Phys. Chem. Chem. Phys. 19, 1798–1805 (2017). T2 - DYSON 2018 CY - Potsdam, Germany DA - 08.10.2018 KW - DNA KW - Dosimetry KW - Electron irradiation KW - Geant4 KW - Hydroxyl radical KW - LET KW - Linear energy transfer KW - Low energy electrons KW - MCS KW - Microdosimetry KW - Monte-Carlo simulations KW - Radiation damage KW - Radiation therapy KW - SEM KW - Electron Microscope KW - LEE KW - Protein PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/46383 AN - OPUS4-46383 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany