Search

Biodegradable cardiovascular stents in magnesium (Mg) alloys constitute a promising option for a less intrusive treatment, due to their high compatibility with the body tissue and intrinsic dissolution in body fluids. The design and fabrication aspects of this medical device require an integrated approach considering different aspects such as mechanical properties, corrosion behaviour and biocompatibility. This work gathers and summarises a multidisciplinary work carried out by three different research teams for the design and fabrication of Mg stents. In particular, the paper discusses the design of the novel stent mesh, the deformability study of the Mg alloys for tubular raw material and laser microcutting for the realisation of the stent mesh. Although, the results are not fully validated as the device has not been fully tested, they show the feasibility of the used approaches, as the first prototype stents in Mg alloy were produced successfully. [ABSTRACT FROM AUTHOR]

Abstract: It was investigated the feasibility of decolorization of an azo dye (DG 26) using a large scale nanotubular TiO2 structured electrode in a laboratory photoelectrochemical reactor (0.8L). Catalyst was grown by anodic oxidation directly on Ti surface and its microstructure and crystalline structure were characterized with SEM and XRD. TiO2/Ti photoactivity under different anodic polarization values was evaluated via photoelectrochemical tests. The nanostructured TiO2 was used in a reactor as photo-anode under UV monochromatic irradiation (254nm) and it was subjected to bias (+1.5V vs. SCE). A comparison with photolysis and photocatalysis processes was carried out under the same operating conditions to evaluate the synergistic action of photocatalysis and TiO2/Ti electrochemical polarization. Electrophotocatalysis was proven to be more effective than photocatalysis in DG 26 decolorization. Catalyst polarization resulted in synergistic effect on process yields. The complete decolorization of a 40mg/L solution of DG 26 was achieved in 24h, without adding chemical reagents, and catalyst durability was demonstrated over 360h tests. Therefore, the work done is challenging to prove that the process (irradiation+catalyst+polarization) is feasible and effectively up-grading to pilot and demonstrative scale applications after a fluid dynamics optimization of the photoreactor. [Copyright &y& Elsevier]