  We study the global existence and uniform-in-time bounds of classical
solutions in all dimensions to reaction-diffusion systems dissipating mass. By
utilizing the duality method and the regularization of the heat operator, we
show that if the diffusion coefficients are close to each other, or if the
diffusion coefficients are large enough compared to initial data, then the
local classical solution exists globally and is bounded uniformly in time.
Applications of the results include the validity of the Global Attractor
Conjecture for complex balanced reaction systems with large diffusion.
