  Studies of mesoscopic structures have now become a leading and rapidly
evolving research field ranging from physics, chemistry, and mineralogy to life
sciences. The increasing miniaturization of devices with length scales of a few
nanometers is leading to radical changes not only in the realization of new
materials but also in shedding light on our understanding of the fundamental
laws of nature that govern the dynamics of systems at the mesoscopic scale. On
the basis of recent experimental results and previous theoretical research, we
investigate thermodynamic processes in small systems in Onsager's region. We
show that fundamental quantities such as the total entropy production, the
thermodynamic variables conjugate to the thermodynamic forces, and the
Glansdorff-Prigogine's dissipative variable may be discretized at the
mesoscopic scale. We establish the canonical commutation rules (ccr) valid at
the mesoscopic scale. The numerical value of the discretization constant is
estimated experimentally. The ultraviolet divergence problem is solved by
applying the correspondence principle with Einstein-Prigogine's fluctuations
theory in the limit of macroscopic sy
