K-ionization and biological effect.
Experimental inactivation cross sections are compared to vacancy production in inner shell (K-shell) of so-called strategic C, N, O atoms of the DNA: in a trial calculation, atoms on the DNA backbone or just contiguous to it are considered as strategic.  Various processes are considered: ionization and electron capture by the primary particle, ionization by secondary electrons.  The last phenomenon is shown to be important for highly charged and medium velocity ions.  A strong similarity is observed between variations versus LET of inactivation and K-vacancy cross sections, especially with regards to LET values for which they maximize: for K-ionization these maxima occur when the ion impact velocity roughly matches the K electron velocity.  It is shown that the "K-hypothesis" allows a quantitative fit of experimental inactivation cross sections if a 4% mean lethal efficiency is attributed to ion-induced K-vacancies in strategic C, N, O atoms.
Chetioui
A
A
Université Paris 7, France.
Guiraud
L
L
Despiney
I
I
Sabatier
L
L
D000818:Animals; D001412:Bacillus subtilis; D002244:Carbon; D016923:Cell Death; D002460:Cell Line; D006224:Cricetinae; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D007477:Ions; D018499:Linear Energy Transfer; D008954:Models, Biological; D009584:Nitrogen; D009686:Nuclear Physics; D010100:Oxygen; D011853:Radiobiology / Q000379:methods*; D012441:Saccharomyces cerevisiae
D007477:Ions; D002244:Carbon; D004247:DNA; D009584:Nitrogen; D010100:Oxygen