Effect of a New High-Pressure Heat Treatment on Additively Manufactured AlSi10Mg Alloy

Metallurgical and Materials Transactions A - The application of an innovative high-pressure T6 treatment (HPT6) to additively manufactured AlSi10Mg alloy is reported in this paper. The aim of this...     

MGMT and Whole-Genome DNA Methylation Impacts on Diagnosis,Prognosis and Therapy of Glioblastoma Multiforme

Epigenetic changes in DNA methylation contribute to the development of many diseases, including cancer. In glioblastoma multiforme, the most prevalent primary brain cancer and an incurable tumor with a median survival time of 15 months, a single epigenetic modification, the methylation of the O⁶-Methylguanine-DNA Methyltransferase (MGMT) gene, is a valid biomarker for predicting response to therapy with alkylating agents and also, independently, prognosis. More recently, the progress from single gene to whole-genome analysis of DNA methylation has allowed a better subclassification of glioblastomas. Here, we review the clinically relevant information that can be obtained by studying MGMT gene and whole-genome DNA methylation changes in glioblastomas, also highlighting benefits, including those of liquid biopsy, and pitfalls of the different detection methods. Finally, we discuss how changes in DNA methylation, especially in glioblastomas bearing mutations in the Isocitrate Dehydrogenase (IDH) 1 and 2 genes, can be exploited as targets for tailoring therapy.     

Preparation and properties of high performance gelatin-based hydrogels with chitosan or hydroxyethyl cellulose for tissue engineering applications

High performance gelatin-based biocompatible hybrid hydrogels are developed using functionalized polyethylene glycol as a cross-linker in presence of chitosan or hydroxyethyl cellulose. Tensile test shows robust and tunable mechanical properties and reveals non-linear and J-shaped stress-strain curves similar to those found for native extracellular matrix. Degradation study demonstrates that the mass loss and change in mechanical properties are dependent on hydrogel composition and cross-linking density. Structural features of the hydrogels are confirmed by infrared spectroscopy. A preliminary biological evaluation is carried out using rat myoblasts and human fibroblasts cell lines. The results show that all hydrogels allow cell adhesion and proliferation during four days culture, hence, they might have a great potential for use in the biomedical applications.     

Effect of the T6 heat treatment on corrosion behavior of additive manufactured and gravity cast AlSi10Mg alloy

This study investigates the corrosion behavior of AlSi10Mg alloy produced by additive manufacturing and gravity casting before and after T6 heat treatment. Electrochemical tests showed that the additive manufactured material in as‐produced condition exhibits high corrosion resistance, due to the very fine microstructure, while immersion test allowed to identify an exfoliation‐like corrosion phenomenon, which caused a significant mass loss. In this case, T6 heat treatment was beneficial for corrosion resistance since the related change in microstructure led to a less detrimental corrosion mechanism. Therefore, the T6 heat treatment resulted necessary to use additive manufactured AlSi10Mg components in aggressive chloride‐bearing environments.     

Round Robin Test for composite-to-brick shear bond characterization

The paper presents the experience of a working group within the RILEM Technical Committee 223-MSC ??Masonry Strengthening with Composite materials??, aimed at developing a standardized, reliable procedure for characterizing the bonding mechanism of masonry elements strengthened with composite materials under shear actions. Twelve laboratories from European universities and research centers were involved. Two different set-ups were compared, for single-lap and double-lap shear tests (the latter in two versions). Four kinds of fiber fabrics, i.e., glass, carbon, basalt and steel, were applied with epoxy resins (wet lay-up system) to clay brick units, for a total of 280 monotonic tests. The results provided information regarding the response of externally bonded-to-brick composites in terms of observed failure mechanisms, load capacity, effective transfer length, and bond shear stress?Cslip behavior. The test results of the 12 laboratories constitute a set of statistically representative data which may conveniently be used for setting appropriate design provisions and guidelines.     

Nanostructured bimetallic alloys prepared via mechanochemical synthesis as PEMFC electrocatalysts for automotive applications

Pt–Co alloys prepared by high energy ball milling synthesis were tested as electrocatalysts for hydrogen fueled Polymer Electrolyte Membrane Fuel Cells (PEMFC). In the present contribution we report on the first results regarding the electrochemical behaviour of two samples of Pt–Co alloys. One sample contains 20 wt.% alloy Pt:Co in the molar ratio 0.25:0.75 and C 80 wt.% and the second one Pt:Co in the molar ratio 0.75:0.25 and C 80 wt.%. The electrochemically active surface (EAS) was determined by cyclic voltammetry data while the electrocatalyst performance in a real cell was obtained by assembling Membrane Electrode Assemblies (MEAs) with the considered sample at the cathode. The results obtained, though indicating a lower performance than all-Pt catalysts, are quite interesting as they point out the importance of the C/Pt, Nafion/Pt and Pt/Co ratios that exert a deep influence onto the cell performance.