  Non-reversing relaxation enthalpies (DHnr) at glass transitions Tg(x) in the
PxGexSe1-2x ternary display a wide, sharp and deep global minimum (~0) in the
0.09 < x < 0.145 range, within which Tg becomes thermally reversing. In the
reversibility window these glasses are found not to age, in contrast to aging
observed for fragile glass compositions outside the window. Thermal
reversibility and lack of aging are paradigms that molecular glasses in the
window share with proteins in transition states, which result from structural
self-organization in both systems. In proteins the self-organized structures
appear to be at places where life sustaining repeating foldings and unfoldings
occur.
