  We study the existence and nonexistence of positive solutions in the whole
Euclidean space of coercive quasi-linear elliptic equations such as \[ \Delta_p
u = f(u)\pm g(\left|\nabla u\right|) \] where $f\in C([0,\infty))$ and $g\in
C^{0,1}([0,\infty)) $ are strictly increasing with $ f(0)=g(0)=0$.
  Among other things we obtain generalized integral conditions of
Keller-Osserman type. In the particular case of plus sign on the right-hand
side we obtain that different conditions are needed when $p\geq 2$ or $p\leq
2$, due to the degeneracy of the operator.
