INVESTIGADORES
RIVAROLA Roberto Daniel
artículos
Título:
Theoretical predictions for ionization cross sections of DNA nucleobases impacted by light ions
Autor/es:
C. CHAMPION, H. LEKADIR, M.E. GALASSI, O. FO`&1800ON RRDD RIVAROLA Y JJ HANSSEN
Revista:
PHYSICS IN MEDICINE AND BIOLOGY
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Bristol (Inglaterra); Año: 2010 vol. 55 p. 6053 - 6067
ISSN:
0031-9155
Resumen:
Induction of DNA double strand breaks after irradiation is considered of prime
importance for producing radio-induced cellular death or injury. However, up
to now ion-induced collisions on DNA bases remain essentially experimentally
approached and a theoretical model for cross section calculation is still lacking.
Under these conditions, we here propose a quantum mechanical description of
the ionization process induced by light bare ions on DNA bases. Theoretical
predictions in terms of differential and total cross sections for proton, á-
particle and bare ion carbon beams impacting on adenine, cytosine, thymine
and guanine bases are then reported in the 10 keV amu−110 MeV amu−1
energy range. The calculations are performed within the first-order Born
approximation (FBA) with biological targets described at the restrictedHartree
Fock level with geometry optimization. Comparisons to recent theoretical data
for collisions between protons and cytosine point out huge discrepancies in
terms of differential aswell as total cross sections whereas very good agreement
is shown with our previous classical predictions, especially at high impact
energies (Ei _ 100 keV amu−1). Finally, in comparison to the rare existing
experimental data a systematic underestimation is observed in particular for
adenine and thymine whereas a good agreement is reported for cytosine. Thus,
further improvements appear as necessary, in particular by using higher order
theories like the continuum-distorted-wave one in order to obtain a better
understanding of the underlying physics involved in such ion-DNA reactions.