Molecular engineering of the glass transition: glass-forming ability across a homologous series of cyclic stilbenes.

We report on the glass-forming abilities of the homologous series 1,2-diphenylcyclo-butene, pentene, hexene and heptene-a series that retains the cis-phenyl configuration characteristic of the well-studied glass former, o-terphenyl. We find that the glass-forming ability shows a sharp maximum for the six-membered ring and demonstrate that this trend in glass-forming ability is a consequence of a maximum, for the 1,2-diphenylcyclohexene, of the reduced glass transition temperature T(g)/T(m). Since the nonmonotonic trend in T(g)/T(m) is entirely due to variations in T(m), we conclude that the design target for maximizing the glass-forming ability across an homologous series should focus on the crystal stability and the factors that determine it.

[Hydrodynamic criteria in the choice of surgical tactics in implanting pulmonary artery trunk prosthesis].

The paper is concerned with the present-day problem of modern medicine, namely with surgical correction of the diseases of the initial part of the pulmonary circulation. The authors suggest hemohydrodynamic simulation of the right heart complicated by extracardial conduit. The simulation was performed at the high theoretical, practical and methodological level to obtain highly significant information which is likely to have paramount importance for clinical practice.