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Protocol for performing angiogenic and tumorigenic assays using the in ovo chick embryo chorioallantoic membrane model
Full text linkThe role of high recycled content and heat treatments on microstructure, mechanical properties, and sustainability for an AlSi10MnMg structural automotive component
No full textSecondary aluminum alloys are produced with end-of-life scraps and are gaining importance for environmental sustainability, thanks to their low intrinsic carbon footprint and energy saving compared to the primary ones. They are increasingly used in the automotive sector for large and complex cast components. However, recycled alloys contaminants like Fe promote the formation of brittle intermetallic compounds, which negatively affect tensile strength and ductility. This study compares the mechanical performance and environmental impact of primary and recycled high pressure die casting AlSi10MnMg (EN AB 43500) alloy under as-produced and heat-treated conditions. Samples were extracted from a die-cast automotive component and subjected to annealing and an optimized T6 heat treatment to balance strength and ductility. Microstructural analysis using field emission scanning electron microscopy revealed a similar pores area fraction, as well as shape, size, and distribution of brittle acicular β-Al5FeSi and polygonal α-Al15(Fe,Mn)3Si2 Fe-rich phases in the primary and recycled alloys under different heat treatment conditions. This similarity justifies the comparable mechanical behavior of the primary and recycled alloy, characterized by limited ductility in the as-produced condition, often insufficient for safety-critical structural components. Heat treatments significantly improved ductility, increasing it by 40–50 % after annealing and nearly doubling it after T6 due to the fragmentation, spheroidization, and coarsening of the eutectic Si. However, the microstructure change reduces strength by a third after annealing and by 20 % after T6, ultimately influencing the final fracture mechanisms. Moreover, heat treatments increase energy consumption, with annealing and T6 leading to about 25 % and 30 % rises, respectively, making them justified only for elongation enhancement
Prognostic value of NT-proBNP in patients with primary mitral regurgitation undergoing transcatheter edge-to-edge repair
No full textAims The prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients undergoing mitral valve transcatheter edge-to-edge repair (M-TEER) for primary mitral regurgitation (PMR) is unclear. This study assessed the association between NT-proBNP and outcomes and explored its additive value to the Mitral Regurgitation International Database (MIDA) score. Methods and results PRIME-MR, a retrospective, international, multicentre registry, includes 3083 consecutive PMR patients treated with M-TEER. This analysis focused on 1382 patients (median age 81 years, 47% female, 82% New York Heart Association [NYHA] functional class III/IV, median EuroSCORE II 4.1%) with available NT-proBNP levels and follow-up. The primary endpoint was death or heart failure hospitalization within 3 years. Median NT-proBNP level was 1991 pg/ml (T1: 578, T3: 6285), and 384 patients reached the primary endpoint (Kaplan-Meier estimate: 48.5%). Log-transformed NT-proBNP levels independently predicted the primary endpoint (adjusted hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.07-1.28; p < 0.001) after adjusting for NYHA class, haemoglobin, creatinine, and atrial fibrillation. In 1041 patients with a modified MIDA score (median 9), the score was initially associated with the primary endpoint (HR 1.10, 95% CI 1.04-1.17; p = 0.002), but lost significance when adjusting for NT-proBNP levels, which remained independently predictive (adjusted HR 1.20, 95% CI 1.07-1.34; p = 0.002). Conclusions NT-proBNP, but not the MIDA score, was independently associated with death or heart failure hospitalizations within 3 years in M-TEER-treated PMR patients. Incorporating NT-proBNP levels into clinical assessment may improve risk stratification and potentially supports earlier intervention at lower NT-proBNP levels to optimize outcomes
Imparare servendo, agire trasformando: Service Learning e pratiche educative per la sostenibilità
No full textStopper vs. Singular Controller Games With Degenerate Diffusions
No full textWe study zero-sum stochastic games between a singular controller and a stopper when the (state-dependent) diffusion matrix of the underlying controlled diffusion process is degenerate. In particular, we show the existence of a value for the game and determine an optimal strategy for the stopper. The degeneracy of the dynamics prevents the use of analytical methods based on solution in Sobolev spaces of suitable variational problems. Therefore we adopt a probabilistic approach based on a perturbation of the underlying diffusion modulated by a parameter γ>0. For each γ>0 the approximating game is non-degenerate and admits a value uγ and an optimal strategy τ∗γ for the stopper. Letting γ→0 we prove convergence of uγ to a function v, which identifies the value of the original game. We also construct explicitly optimal stopping times θ∗γ for uγ, related but not equal to τ∗γ, which converge almost surely to an optimal stopping time θ∗ for the game with degenerate dynamics
Exploring mental health of Italian college students: a systematic review and meta-analysis
Full text linkIntroductionThe transition from adolescence to adulthood is characterized by changes and challenges for students, that can affect their mental well-being. Furthermore, mental disorders often emerge before the age of 24, underscoring the significance of addressing mental health during the college years. The study's objective is to conduct a systematic review of the mental health of Italian university students, exploring the prevalence of psychopathological dimensions, identifying risk and protective factors, and investigating the impact on academic performance.MethodsThe initial search yielded 842 papers. After the screening process, a total of 27 studies were included (22,928 participants).ResultsThe prevalence of mental distress is notable: stress affects 72.6%, anxiety 61.8%, depression 41.6%, sleep disorders 63.9%, and suicide risk 6.1%.DiscussionBiological factors like chronic illness and family history increase the risk of psychological disorders. Psychological factors, including sexual orientation, play a role. Dysfunctional personality traits, adverse events, financial concerns, and the pandemic amplify distress. Resilience, coping strategies, peer support, inclusive environments, physical activity, and balanced lifestyles act as protective factors. Mental distress impacts academic performance and often is exacerbated by the pressure to excel. Interventions encompass targeted support, cognitive-behavioral therapy, and the promotion of inclusive and supportive environments
Efficacy of mechanochemically prepared ceria–zirconia catalysts in ketonisation of acetic acid
Full text linkThis work presents a comprehensive study on the catalytic and kinetic aspects of the ketonisation of acetic acid, a model volatile fatty acid, using Ce1−xZrxO2 as catalysts. Volatile fatty acids are promising biomass derived feedstock for production of drop-in sustainable aviation fuels through a series of cascade reactions, with ketonisation as the first step followed by aldol condensation and subsequent hydrogenation. A series of Ce1−xZrxO2 catalysts for ketonisation were prepared using a mechanochemical technique of ball milling, and their performance was evaluated for varying Ce/Zr mole ratios. Among the catalysts tested, Ce0.75Zr0.25O2 exhibited the highest conversion and selectivity towards the desired product, acetone. The catalyst characterisation showed the formation of nano-aggregates with an average particle size of 340.8 nm and a specific surface area of 66.2 m2 g−1. The kinetics of the reaction indicated a second-order dependence on acetic acid, while the products (acetone, water, and CO2) exhibited negative orders, suggesting competitive adsorption on the active sites of the catalyst. The activation energy for the reaction was determined to be 103.4 kJ mol−1 suggesting the surface reaction as the rate controlling step. These findings provide valuable insights into the catalytic behaviour and kinetics of the ketonisation reaction
