  The purpose of this review is to revisit recent results in the literature
where quantum plasmas with arbitrary degeneracy degree are considered. This is
different from a frequent approach, where completely degeneracy is assumed in
dense plasmas. The general reasoning in the reviewed works is to take a
numerical coefficient in from of the Bohm potential term in quantum fluids, in
order to fit the linear waves from quantum kinetic theory in the long
wavelength limit. Moreover, the equation of state for the ideal Fermi gas is
assumed, for arbitrary degeneracy degree. The quantum fluid equations allow the
expedite derivation of weakly nonlinear equations from reductive perturbation
theory. In this way, quantum Korteweg - de Vries and quantum Zakharov -
Kuznetsov equations are derived, together with the conditions for bright and
dark soliton propagation. Quantum ion-acoustic waves in unmagnetized and
magnetized plasmas, together with magnetosonic waves, have been obtained for
arbitrary degeneracy degree. The conditions for the application of the models,
and the physical situations where the mixed dense - dilute systems exist, have
been identified.
