  Radiative losses from optically thin plasma are an important ingredient for
modeling plasma confined in the solar corona. Spectral models are continuously
updated to include the emission from more spectral lines, with significant
effects on radiative losses, especially around 1 MK. We investigate the effect
of changing the radiative losses temperature dependence due to upgrading of
spectral codes on predictions obtained from modeling plasma confined in the
solar corona. The hydrodynamic simulation of a pulse-heated loop strand is
revisited comparing results using an old and a recent radiative losses
function. We find significant changes in the plasma evolution during the late
phases of plasma cooling: when the recent radiative loss curve is used, the
plasma cooling rate increases significantly when temperatures reach 1-2 MK.
Such more rapid cooling occurs when the plasma density is larger than a
threshold value, and therefore in impulsive heating models that cause the loop
plasma to become overdense. The fast cooling has the effect of steepening the
slope of the emission measure distribution of coronal plasmas with temperature
at temperatures lower than ~2 MK. The effects of changes in the radiative
losses curves can be important for modeling the late phases of the evolution of
pulse-heated coronal loops, and, more in general, of thermally unstable
optically thin plasmas.
