Multicaloric effect in a multiferroic composite of Gd5(Si,Ge)4 microparticles embedded into a ferroelectric PVDF matrix.

The coupling between electric, magnetic and elastic features in multiferroic materials is an emerging field in materials science, with important applications on alternative solid-state cooling technologies, energy harvesting and sensors/actuators. In this direction, we developed a thorough investigation of a multiferroic composite, comprising magnetocaloric/magnetostrictive Gd[Formula: see text]Si[Formula: see text]Ge[Formula: see text] microparticles blended into a piezo- and pyroelectric poly(vinylidene) fluoride (PVDF) matrix. Using a simple solvent casting technique, the formation and stabilization of PVDF electroactive phases are improved when the filler content increases from 2 to 12 weight fraction (wt.%). This effect greatly contributes to the magnetoelectric (ME) coupling, with the ME coefficient [Formula: see text] increasing from 0.3 V/cm.Oe to 2.2 V/cm.Oe, by increasing the amount of magnetic material. In addition, magnetic measurements revealed that the ME-coupling has influenced the magnetocaloric effect via a contribution from the electroactive polymer and hence leading to a multicaloric effect. These results contribute to the development of multifunctional systems for novel technologies.

Tailoring the morphology of high molecular weight PLLA scaffolds through bioglass addition.

Thermally induced phase separation (TIPS) has proven to be a suitable method for the preparation of porous structures for tissue engineering applications, and particular attention has been paid to increasing the pore size without the use of possible toxic surfactants. Within this context, an alternative method to control the porosity of polymeric scaffolds via the combination with a bioglass is proposed in this work. The addition of a bioactive glass from the 3CaO x P2O5-MgO-SiO2 system enables the porous structure of high molecular weight poly(l-lactic) acid (PLLA) scaffolds prepared by TIPS to be tailored. Bioglass acts as a nucleating catalyst agent of the PLLA matrix, promoting its crystallization, and the glass solubility controls the pore size. A significant increase in the pore size is observed as the bioglass content increases and scaffolds with large pore size (approximately 150 microm) can be prepared. In addition, the bioactive character of the scaffolds is proved by in vitro tests in synthetic plasma. The importance of this approach resides on the combination of the ability to tailor the porosity of polymeric scaffolds via the tunable solubility of bioglasses, without the use of toxic surfactants, leading to a composite structure with suitable properties for bone tissue engineering applications.

Syntheses of beta-D-GalpNAc4SO3-(1-->4)-L-IdopA2SO3, a disaccharide fragment of dermatan sulfate, and of its methyl alpha-L-glycoside derivative.

The syntheses of sodium (sodium 2-acetamido-2-deoxy-4-O-sulfonato-beta-D-galactopyranosyl)-(1-->4)-(sodium 2-O-sulfonato-L-idopyran)uronate, a disaccharide fragment of dermatan sulfate, and of its methyl alpha-L-glycoside derivative are reported for the first time. The use of 4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-trichloroacetamido-1-O-trichloroacetimidoyl-alpha-D-galactopyranose, readily prepared from a D-gluco precursor, allowed the stereocontrolled and high yielding coupling with the low reactive 4-hydroxyl group of L-iduronic acid ester derivatives. Classical transformation of the disaccharide products into the target molecules was achieved in high yield.