Nsurviv/N0 is the part of cells surviving after getting P1, P2, P3, P4 injuries;
• τ2, τ3, τ4 are the average times for reparation of easily and heavily destroyed intracellular components
and DNA (it is assumed that typical exposure time under NTP sterilization is shorter
compared with reparation time of the membrane(s) structures and cell wall