Experimental characterization of SLM and EBM cubic lattice structures for lightweight applications

This study carries out an experimental characterization of lattice structures that are based on cubic cells fabricated through selective laser melting (SLM) and electron beam melting (EBM). The lattice failure under compressive load is studied as a function of the process typology, material properties, and dimensional parameters of the unit cell. The bulk material is first characterized to evaluate the process stability. Three main failure modes of the lattice are identified, depending on the response of ductile/brittle material and the direction of crack propagation. The relationship between lattice geometrical parameters and mechanical strength is observed. The results of the modeling and experiments are suitable to validate the design of lightweight components built with AM processes. The structural performances related to geometrical features, material properties and technological constraints are well explained for further applications in structural design. The equivalent Young’s module of lattice samples with different cell size has been measured and compared with numerical simulations based on the homogenization method

Un-making childhood disability: the everyday practices of health and social workers, and the role of research

Nel presente lavoro di tesi si sostiene che la disabilità infantile si produce nelle pratiche lavorative di operatrici e operatori dei servizi il cui agire diviene dis-abilitante poiché fortemente vincolato alle forme istituzionali, materiali e simboliche, della relazione terapeutica ed educativa. Attraverso la relazione individuale con l'educatrice/ore, l'abitudine a tenere il ragazzo certificato fuori dalla classe, l'orientamento scolastico alle scuole professionali, l'impossibilità di costruire percorsi educativi continuativi e in contesti eterogenei, ma anche attraverso i numerosi documenti necessari per attivare i percorsi di integrazione scolastica e le normative emesse dal Ministero dell'Istruzione, la disabilità viene quotidianamente prodotta e riprodotta. Questa, infatti, non pre-esiste alle pratiche che vengono messe in atto ma è parte di esse. Allo stesso tempo tale riproduzione coesiste sempre con tentativi di trasformazione che il “lavoro vivo”, di relazione (di cura o educativa), necessariamente implica. Parallelamente, nel corso dell'elaborato, viene sviluppata una riflessione sul ruolo sociale della ricerca come dispositivo di trasformazione. La ricerca(trice) che riconosce questo spazio di tensione tra riproduzione e trasformazione nel lavoro di operatrici e operatori può infatti scegliere di sostenere , attraverso il metodo stesso di ricerca, l'una o l'altra tendenza. Nel caso in cui si opti per la seconda è prima di tutto la pratica di ricerca a divenire campo di partecipazione e terreno di negoziazione per le alternative possibili e percorribili. Un necessario passo verso il cambiamento parte dunque dal riconoscere che tra ricercatrici/ricercatori e soggetti della ricerca, così come tra operatrici/operatori e “utenti”, vi è un campo comune di bisogni e intenti a partire dal quale solamente si possono ri-costruire pratiche educative, di cura e di liberazione.The present thesis states that childhood disability is produced in the everyday practices of health and social workers. Their practices become dis-abling because are strongly tied to the institutionalized forms, material and symbolic, of the therapeutic and educational relation. Through the individualization of the relation with the educator, the habit of taking the “certified” child out of the class, the tendency to orient disable students to professional schools, the impossibility of creating continuous and heterogeneous educational paths, but also through the many documents needed to start school integration programs, disability is daily produced and reproduced, it is enacted. Disability does not pre-exist workers practices, but is part of them. At the same time reproduction always coexists with the possibility of difference and attempts to transformation. This tension is in fact constitutive of “live work in action” implicated in therapeutic and educational relation. Simultaneously in the thesis, the author develops a reflection on the social role of research as a tool for transformation. The research(er) who recognizes this “field of tension” between reproduction and transformation in the practices of health and social workers may choose to sustain, through the method of the research itself, the first or the second tendency. If we decide to choose the second, the practice of research first of all becomes a field of participation and negotiation for alternative possibilities. A necessary step towards change, thus, starts from recognizing that there are common needs and intents between researchers and subjects of research, and between social/health workers and “users”. Only from this common ground it is possible to re-build practices of care, education and liberation

When a Friend Becomes Your Enemy: Natural Killer Cells in Atherosclerosis and Atherosclerosis-Associated Risk Factors

Atherosclerosis (ATS), the change in structure and function of arteries with associated lesion formation and altered blood flow, is the leading cause of cardiovascular disease, the number one killer worldwide. Beyond dyslipidemia, chronic inflammation, together with aberrant phenotype and function of cells of both the innate and adaptive immune system, are now recognized as relevant contributors to atherosclerosis onset and progression. While the role of macrophages and T cells in atherosclerosis has been addressed in several studies, Natural Killer cells (NKs) represent a poorly explored immune cell type, that deserves attention, due to NKs’ emerging contribution to vascular homeostasis. Furthermore, the possibility to re-polarize the immune system has emerged as a relevant tool to design new therapies, with some succesfull exmples in the field of cancer immunotherapy. Thus, a deeper knowledge of NK cell pathophysiology in the context of atherosclerosis and atherosclerosis-associated risk factors could help developing new preventive and treatment strategies, and decipher the complex scenario/history from “the risk factors for atherosclerosis” Here, we review the current knowledge about NK cell phenotype and activities in atherosclerosis and selected atherosclerosis risk factors, namely type-2 diabetes and obesity, and discuss the related NK-cell oriented environmental signals

Effects of Curing on Photosensitive Resins in {SLA} Additive Manufacturing

Different mechanical properties characterise the materials of 3D printed components, depending on the specific additive manufacturing (AM) process, its parameters, and the post-treatment adopted. Specifically, stereolithography (SLA) uses a photopolymerisation technique that creates solid components through selective solidification. In this study, 72 specimens were 3D printed using 12 commercial-grade methacrylate resins and tested under uniaxial tensile loads. The resin specimens were evaluated before and after curing. The recommended cure temperature and time were followed for all materials. The stress-strain curves measured during the testing campaign were evaluated in terms of maximum tensile strength, Young’s modulus, ductility, resilience, and toughness. The results reveal that the curing process increases the material stiffness and resistance to tensile loads. However, it was found that the curing process generally reduces the plasticity of the resins, causing a more or less marked brittle behaviour. This represents a potential limitation to the use of SLA 3D printing for structural elements which require some plasticity to avoid dangerous sudden failures

Effects of Curing on Photosensitive Resins in {SLA} Additive Manufacturing

Different mechanical properties characterise the materials of 3D printed components, depending on the specific additive manufacturing (AM) process, its parameters, and the post-treatment adopted. Specifically, stereolithography (SLA) uses a photopolymerisation technique that creates solid components through selective solidification. In this study, 72 specimens were 3D printed using 12 commercial-grade methacrylate resins and tested under uniaxial tensile loads. The resin specimens were evaluated before and after curing. The recommended cure temperature and time were followed for all materials. The stress-strain curves measured during the testing campaign were evaluated in terms of maximum tensile strength, Young’s modulus, ductility, resilience, and toughness. The results reveal that the curing process increases the material stiffness and resistance to tensile loads. However, it was found that the curing process generally reduces the plasticity of the resins, causing a more or less marked brittle behaviour. This represents a potential limitation to the use of SLA 3D printing for structural elements which require some plasticity to avoid dangerous sudden failures

The transformative potential of health as a Commons

Italy was a participating country in the People’s Health Movement multi-centred action-research project (Civil Society Engagement for Health for All). The Italian team, a collective named Grup-pa, undertook several participatory action-research activities including, in a first phase, a mapping of groups active in fields linked to the social determination of health and health promotion, through individual and collective interviews. In a second phase, three public workshops, structured around the exchange of practices, focused on key themes emerged from phase one. A major construct originated from this work, centred around the co-construction of experiential knowledge on health as a commons, has been named ‘health commons practices’. The focus on practices is not merely strategic (producing synergies and alliances), but inherently political (conceiving participation as a value) and connected to health and staying healthy (as individuals; as a community). The construct of ‘health commons practices’ is meant to make visible an area of ongoing transformations in new spaces created by movements and in more traditional actions in defence of existing public services, addressing health as a socio-political issue. In this essay, we sketch the reflection around six keywords that are central to it: commons, care, technology, efficacy, sustainability, institution

Candidate biomarkers from the integration of methylation and gene expression in discordant autistic sibling pairs

While the genetics of autism spectrum disorders (ASD) has been intensively studied, resulting in the identification of over 100 putative risk genes, the epigenetics of ASD has received less attention, and results have been inconsistent across studies. We aimed to investigate the contribution of DNA methylation (DNAm) to the risk of ASD and identify candidate biomarkers arising from the interaction of epigenetic mechanisms with genotype, gene expression, and cellular proportions. We performed DNAm differential analysis using whole blood samples from 75 discordant sibling pairs of the Italian Autism Network collection and estimated their cellular composition. We studied the correlation between DNAm and gene expression accounting for the potential effects of different genotypes on DNAm. We showed that the proportion of NK cells was significantly reduced in ASD siblings suggesting an imbalance in their immune system. We identified differentially methylated regions (DMRs) involved in neurogenesis and synaptic organization. Among candidate loci for ASD, we detected a DMR mapping to CLEC11A (neighboring SHANK1) where DNAm and gene expression were significantly and negatively correlated, independently from genotype effects. As reported in previous studies, we confirmed the involvement of immune functions in the pathophysiology of ASD. Notwithstanding the complexity of the disorder, suitable biomarkers such as CLEC11A and its neighbor SHANK1 can be discovered using integrative analyses even with peripheral tissues

CRISIS AFAR: an international collaborative study of the impact of the COVID-19 pandemic on mental health and service access in youth with autism and neurodevelopmental conditions

BackgroundHeterogeneous mental health outcomes during the COVID-19 pandemic are documented in the general population. Such heterogeneity has not been systematically assessed in youth with autism spectrum disorder (ASD) and related neurodevelopmental disorders (NDD). To identify distinct patterns of the pandemic impact and their predictors in ASD/NDD youth, we focused on pandemic-related changes in symptoms and access to services.MethodsUsing a naturalistic observational design, we assessed parent responses on the Coronavirus Health and Impact Survey Initiative (CRISIS) Adapted For Autism and Related neurodevelopmental conditions (AFAR). Cross-sectional AFAR data were aggregated across 14 European and North American sites yielding a clinically well-characterized sample of N = 1275 individuals with ASD/NDD (age = 11.0 ± 3.6 years; n females = 277). To identify subgroups with differential outcomes, we applied hierarchical clustering across eleven variables measuring changes in symptoms and access to services. Then, random forest classification assessed the importance of socio-demographics, pre-pandemic service rates, clinical severity of ASD-associated symptoms, and COVID-19 pandemic experiences/environments in predicting the outcome subgroups.ResultsClustering revealed four subgroups. One subgroup-broad symptom worsening only (20%)-included youth with worsening across a range of symptoms but with service disruptions similar to the average of the aggregate sample. The other three subgroups were, relatively, clinically stable but differed in service access: primarily modified services (23%), primarily lost services (6%), and average services/symptom changes (53%). Distinct combinations of a set of pre-pandemic services, pandemic environment (e.g., COVID-19 new cases, restrictions), experiences (e.g., COVID-19 Worries), and age predicted each outcome subgroup.LimitationsNotable limitations of the study are its cross-sectional nature and focus on the first six months of the pandemic.ConclusionsConcomitantly assessing variation in changes of symptoms and service access during the first phase of the pandemic revealed differential outcome profiles in ASD/NDD youth. Subgroups were characterized by distinct prediction patterns across a set of pre- and pandemic-related experiences/contexts. Results may inform recovery efforts and preparedness in future crises; they also underscore the critical value of international data-sharing and collaborations to address the needs of those most vulnerable in times of crisis

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field