  The two-dimensional Hubbard model is studied within the Composite Operator
Method (COM) with the residual self-energy computed in the Self-Consistent Born
Approximation (SCBA). COM describes interacting electrons in terms of the new
elementary excitations appearing in the system owing to strong correlations;
residual interactions among these excitations are treated within the SCBA. The
anomalous features appearing in the spectral function A(k,\omega), the momentum
distribution function n(k) and the Fermi surface are analyzed for various
values of the filling (from overdoped to underdoped region) in the intermediate
coupling regime at low temperatures. For low doping, in contrast with the
ordinary Fermi-liquid behavior of a weakly-correlated metal found at high
doping, we report the opening of a pseudogap and some non-Fermi-liquid features
as measured for cuprates superconductors. In addition, we show the presence of
kinks in the calculated electronic dispersion in agreement with ARPES data.
