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Electron-Impact Ionization and Dissociative Ionization of BiomoleculesIt is well recognized that secondary electrons play an important role in radiation damage to humans. Particularly important is the damage of DNA by electrons, potentially leading to mutagenesis. Molecular-level study of electron interaction with DNA provides information on the damage pathways and dominant mechanisms. Our study of electron-impact ionization of DNA fragments uses the improved binary-encounter dipole model and covers DNA bases, sugar phosphate backbone, and nucleotides. An additivity principle is observed. For example, the sum of the ionization cross sections of the separate deoxyribose and phosphate fragments is in close agreement with the C3(sup prime)- and C5 (sup prime)-deoxyribose-phospate cross sections, differing by less than 5%. Investigation of tandem double lesion initiated by electron-impact dissociative ionization of guanine, followed by proton reaction with the cytosine in the Watson-Crick pair, is currently being studied to see if tandem double lesion can be initiated by electron impact. Up to now only OH-induced tandem double lesion has been studied.
Document ID
20070002966
Document Type
Conference Paper
Authors
Huo, Winifred M. (NASA Ames Research Center Moffett Field, CA, United States)
Chaban, Galina M. (NASA Ames Research Center Moffett Field, CA, United States)
Dateo, Christopher E. (Eloret Corp. Mountain View, CA, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2006
Subject Category
Aerospace Medicine
Meeting Information
APS 37th DAMOP Meeting(Knoxville, TN)
Distribution Limits
Public
Copyright
Other