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Title: Note: Transient negative ions as initiators of oxygen fixation in <20 eV electron-irradiated DNA

This note represents a significant addition to our previous manuscript [N. Mirsaleh-Kohan, A. D. Bass, P. Cloutier, S. Massey, and L. Sanche, J. Chem. Phys. 136, 235104 (2012)] where we demonstrated that enhancements in the electron stimulated desorption yields of O{sup −} and OH{sup −} from O{sub 2} exposed DNA samples were due to the reactions of O{sub 2} with electron-induced damage sites within the DNA. Here, we investigate the attachment of O{sub 2} to electron-irradiated DNA as a function of electron energy and find a local maximum for O{sub 2} attachment to DNA at ∼11.4 eV. This reaction is likely initiated by the production of transient negative ions that dissociate to form RCH{sub x−1}{sup •} radicals. This work is thus relevant to our understanding of how O{sub 2} modulates radiation induced damage in cellular DNA and upon the question of the radio-sensitization of cells during, for example, radiotherapy.
Authors:
; ;  [1]
  1. Groupe en sciences des radiations, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4 (Canada)
Publication Date:
OSTI Identifier:
22220241
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 18; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 60 APPLIED LIFE SCIENCES; 62 RADIOLOGY AND NUCLEAR MEDICINE; BIOLOGICAL EFFECTS; DESORPTION; DISSOCIATION; DNA; ELECTRONS; IRRADIATION