“…Though several gradient estimate results have been obtained in different cases (see, e.g., [2,5,8,9,13,14,16,17,[23][24][25][26][27][28]), we provide here a general framework dealing, at once, with various nonlinearities of interest (as a matter of fact, a number of classical and recent results can be re-obtained as special cases of our general approach). Also, we will provide "global" (rather than "local") estimates that take into account the parabolic boundary behavior, thus improving the estimates when the data of the equation are particularly favorable.…”