Copolymerization of β-Butyrolactones into Functionalized Polyhydroxyalkanoates Using Aluminum Catalysts: Influence of the Initiator in the Ring-Opening Polymerization Mechanism.

Within bioplastics, natural poly(3-hydroxybutyrate) (PHB) stands out as fully biocompatible and biodegradable, even in marine environments; however, its high isotacticity and crystallinity limits its mechanical properties and hence its applications. PHB can also be synthesized with different tacticities via a catalytic ring-opening polymerization (ROP) of rac-β-butyrolactone (BBL), paving the way to PHB with better thermomechanical and processability properties. In this work, the catalyst family is extended based on aluminum phenoxy-imine methyl catalyst [AlMeL], that reveals efficient in the ROP of BBL, to the halogeno analogous complex [AlClL].

Cardiac troponin I serum concentrations in newborns: a study and review of the literature.

Background: Serum cardiac troponin I (cTnI) is a specific marker of cardiac injury. The use of cTnI in neonates, especially in relation to perinatal asphyxia has not been extensively examined. We defined the range of normal values of cTnI in newborns, and study factors that may influence these concentrations.