Concluding Notes

Abstract

In various fields of research, scientists are finding that heterogeneity is everywhere: the heterogeneous conditions prevail in numerous physical, chemical, physiological, and biochemical processes. Indeed, many reactions and processes take place under dimensional or topological constraints that introduce structural heterogeneity. In parallel, drug molecules can differ in their kinetic behavior because of inherent variability in their characteristics such as molecular weight, chemical composition, or hepatic clearance involving a large number of metabolites. All these features introduce functional heterogeneity. Structural and functional heterogeneities can be described and understood with the concept of fractals.