New exact fronts for the nonlinear diffusion equation with quintic   nonlinearities
  We consider travelling wave solutions of the reaction diffusion equation with quintic nonlinearities $u_t = u_{xx} + \mu u (1 -u )   ( 1 +\alpha u + \beta u^2 +\gamma u^3)$. If the parameters $\alpha , \beta$ and $\gamma$ obey a special relation, then the criterion for the existence of a strong heteroclinic connection can be expressed in terms of two of these parameters. If an additional restriction is imposed, explicit front solutions can be obtained. The approach used can be extended to polynomials whose highest degree is odd. 
R. D. Benguria and M. C. Depassier (Facultad de Fisica, P. Universidad   Catolica de Chile, Santiago, Chile)