RT Journal Article ID 0392af0f0bd32877 A1 Boissiere, Arnaud A1 Eschenbrenner, Anne A1 Gobert, Francois A1 du Penhoat, Marie-Anne Herve A1 Abel, Francois A1 Lamoureux, Michele A1 Martins, Luis A1 Politis, Marie-Francoise A1 Ricoul, Michele A1 Touati, Alain A1 Sage, Evelyne A1 Sabatier, Laure A1 Chetioui, Annie T1 Cellular Inactivation and Chromosomal Aberrations: Initial Damage JF Journal of Environmental Pathology, Toxicology and Oncology JO JEP(T) YR 2004 FD 2004-06-08 VO 23 IS 2 OP 10 AB It has been proposed that unrepaired or misrepaired complex lesions of DNA are responsible for cell inactivation and chromosomal aberrations. The detailed features of the critical damage and the nature of initiating physical events are actively investigated. We studied the role of inner-shell (core) ionizations in DNA atoms is studied. Ultrasoft X-rays from LURE synchrotron radiation have been used to mimic core events induced by ionizing radiations. For biological matter, inner-shell photoionization is indeed the main interaction channel of these radiations. Moreover, by tuning the X-ray energy below and above the carbon K-threshold, it is possible to achieve a two-fold increase in the number of core-ionizations in DNA for a same dose. Cell survival and chromosome aberrations have thus been studied at three iso-attenuated energies: 250,350, and 810 eV. Relative biological efficiencies (RBEs) for cell inactivation and chromosome aberrations were found to be strongly correlated with the yields of core events in DNA. PB Begell House LK https://www.dl.begellhouse.com/journals/0ff459a57a4c08d0,69988c136ea159a9,0392af0f0bd32877.html