  We present updated predictions of effective elastic nucleon-nucleon cross
sections intended for use in nucleus-nucleus reactions. A novel characteristic
of the present approach combines all microscopic medium effects included in the
Dirac-Brueckner-Hartree-Fock G-matrix with a Pauli blocking mechanism which is
more appropriate for applications in ion-ion reaction models as compared to a
previous approach. The effective in-medium cross section is found to be quite
sensitive to the description of Pauli blocking in the final configurations.
