Three novel narrowly distributed rod-coil diblock copolymers, poly (styrene-block-(2,5-bis-[4-methoxyphenyl]oxycarbonyl)styrene) (PS-b-PMPCS), with same PS block length and different PMPCS lengths, were synthesized by 2,2,6,6-tetramethyl-1-piperidinyloxy-(TEMPO-) mediated living free radical polymerization. The self-assembly behavior of the block copolymers in p-xylene, which is a good solvent for the PS coils and a selective solvent for the PMPCS rods, was studied by dynamic and static laser light scattering (LLS) and transmission electron microscopy (TEM). The critical association concentration (CAC) for each copolymer was determined and was found to decrease as the molecular weight of the rods increases. We found that the molar mass of the self-assembled nanostructures increased very fast near CAC, while this slows at concentrations much higher than CAC. Dynamic and static LLS revealed that the block copolymers formed core-shell nanostructure in the concentrations we observed, and the radius of the core was calculated. The core-shell nanostructure was also confirmed by TEM images. The calculated radius of the core was compared to the TEM results, and it was found to be compatible.

A 53 year old man with a large mesenchymal hamartoma is reported. Only a few bile ducts could be found in the periphery of the lesion and no hepatocytes were identified within the lesion. As far as is known, this is the only adult male patient reported to date. On the basis of the reported findings of mesenchymal hamartoma in other adults, it is suggested that there could be changes in the morphology of this lesion with age: progressive loss of hepatocytes; degeneration of bile duct epithelium; and cystic change of the mesenchymal component. The haematopoietic element is considered to be part of the fetal hepatic haematopoiesis that occurs in the hamartoma.