# Negative absolute pressure with positive absolute temperature

Could I ask if the derivative defining pressure $dU \over dV$ or ${∂S \over ∂V}|_{E,N}$can be negative in processes occuring in system not cosmological but statistical(gases or solids or liquids-I mean the statistical study of systems). Altough I have read about negative temperatures and negative pressures, could we have for a system at positive temperature, a negative price of pressure(absolute)?

Thank you.