Self-perpetuating structures

Dislocations can occur within crystals as a result of stresses in crystal growth on seeds and around surface nuclei and inclusions. Spiral and other self-perpetuating growth can promote growth rate dispersion (different growth rates on different crystals of the same material) because each crystal is responding to the structure of its own unique dislocation(s). 

In this chapter, the consequences of the irregular structure and function of the tumor microcirculation and the self-perpetuating hostile pathophysiological microenvironment (via a vicious circle) will be described. This overview considers, inter alia, many metabolic, biophysical, and physico-biochemical parameters of the tumor microenvironment rather than focusing on the complex composition of the tumor stroma, the cells therein, and their factors secreted, the key components of the tumor stroma, and the interactions between tumor cells, the extracellular matrix, and stromal cells (for reviews see, e.g., Mueller and Fusenig 2004 Witz and Levy-Nissenbaum 2006 Weinberg 2008 Ariztia etal. 2006 Cunha etal. 2003 Park etal. 2000 Liotta and Kohn 2001 Fidler 2002 Unger and Weaver 2003 Denko et al. 2003). 

In liquid water, the thermal motions of molecules are perpetual, and the relative positions of the molecules are changing all the time. Although the structure of liquid water has no definite pattern, the hydrogen bonds between molecules still exist in large numbers. Thus liquid water is a dynamic system in which the H2O molecules self-assemble in perfect, imperfect, isolated, linked and fused polyhedra (Fig. 16.3.3), among which the pentagonal dodecahedron takes precedence. 

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