Novel functionalized calcium phosphates: structures, morphologies and potential applications.

The stable increase in average life expectancy and the consecutive increase in the number of cases of bone related diseases has led to a growing interest in the development of materials that can promote bone repair and/or replacement. Among the best candidates are those materials that have a high similarity to bones, in terms of composition, structure, morphology and functionality. Biomineralized tissue, and thus also bones, have three main components: water, an organic matrix and an inorganic deposit. In vertebrates, the inorganic deposit consists of what is called biological apatite, which slightly differ from stoichiometric hydroxyapatite (HA) both in crystallographic terms and in the presence of foreign atoms and species. This justifies the great attention towards calcium phosphates, which show excellent biocompatibility and bioactivity. The performances of the material and the response of the biological tissue can be further improved through their functionalization with ions, biologically active molecules and nanostructures. This thesis focuses on several possible functionalizations of calcium phosphates, and their effects on chemical properties and biological performances. In particular, the functionalizing agents include several biologically relevant ions, such as Cobalt (Co), Manganese (Mn), Strontium (Sr) and Zinc (Zn); two organic molecules, a flavonoid (Quercetin) and a polyphenol (Curcumin); and nanoparticles, namely tungsten oxide (WO3) NPs. Functionalization was carried out on various calcium phosphates: dicalcium phosphate dihydrate (DCPD), dicalcium phosphate anhydrous (DCPA) and hydroxyapatite (HA). Two different strategies of functionalization were applied: direct synthesis and adsorption from solution. Finally, a chapter is devoted to a preliminary study on the development of cements based on some of the functionalized phosphates obtained.

Obesità infantile: abitudini alimentari e stili di vita delle famiglie. Un'analisi sociologica sul territorio riminese

L'obesità infantile può essere considerata una delle maggiori sfide sanitarie del XXI secolo. In Italia, la fascia d'età più colpita è quella tra i 6 e gli 11 anni. L'infanzia e l'adolescenza non solo influenzano lo sviluppo fisico, cognitivo e sociale dell'adulto, ma anche l'aspettativa di vita. Inoltre, l'interruzione dell'insegnamento in classe e le misure di contenimento di Covid-19 hanno aumentato il comfort food, la sedentarietà e la vulnerabilità socio-economica delle famiglie. Lo scopo del lavoro di ricerca è stato quello di studiare i fattori sociali che hanno influenzato le abitudini alimentari e gli stili di vita delle famiglie con bambini di età compresa tra i 6 e gli 11 anni, all'interno dell'ambiente di socializzazione primario (famiglia) e secondario (scuola e altre istituzioni) anche durante la pandemia di COVID-19. La ricerca è stata condotta in Emilia-Romagna nella città di Rimini e poi estesa al contesto europeo contemporaneo. Per indagare questo punto, è stata utilizzata una metodologia in parte qualitativa e in parte quantitativa. L'approccio mosaico composto da 15 interviste semi-strutturate; 8 focus group e 5 etnografie ha permesso di costruire un questionario, online e cartaceo, somministrato a 361 genitori. I principali risultati rivelano che (1) i bambini sono ingrassati durante il periodo di Covid; (2) esiste una correlazione tra il peso della madre e il peso del bambino; (3) le madri sottovalutano l'obesità dei figli.

“Study of Electro-thermal Effects on PLA Materials Fed with AC Currents”

Given the rise in the emergence of new composite materials, their multifunctional properties, and possible applications in simple and complex structural components, there has been a need to unravel the characterization of these materials. The possibility of printing these conductive composite materials has opened a new area in the design of structural components which can conduct, transmit, and modulate electric signals with no limitation from complex geometry. Although several works have researched the behaviour of polymeric composites due to the immediate growth, however, the electrothermal behaviour of the material when subjected to varying AC applied voltage (Joule’s effect) has not been thoroughly researched. This study presents the characterization of the electrothermal behaviour of conductive composites of a polylactic acid matrix reinforced with conductive carbon black particles (CB-PLA). An understanding of this behaviour would contribute to the improved work in additive manufacturing of functional electro-mechanical conductive materials with potential application in energy systems, bioelectronics, etc. In this study, the electrothermal interplay is monitored under applied AC voltage, varying lengths, and filament printing orientations (longitudinal, oblique, and transverse). Each sample was printed using the fused deposition modeling technique such that each specimen has three different lengths (1L, 2L, 2.75L). To this end, deductions were made on properties that affect composite’s efficiency and life expectancy. The result of this study shows a great influence of printing orientation on material properties of 3D printed conductive composites of CB-PLA. The result also identifies the contribution of AC applied voltage to composites' stabilization time. This knowledge is important to provide experimental background for components' electrothermal interplay, estimate possible degradation and operating limits of composite structures when used in applications.