Stroke epidemiology and COVID-19 pandemic

PURPOSE OF REVIEW: The aim of this study was to describe the impact of the COVID-19 outbreak on the epidemiology, cause and clinical characteristics of incident stroke in different settings and populations. RECENT FINDINGS: Several studies have shown that there are three main themes in the epidemiology of stroke during the COVID-19 pandemic: COVID-19 seems to be associated with stroke in a significant number of patients. This association has been reported in several clinical series, mainly from China. There is a consistent trend towards a decreased number of hospital admissions of stroke patients during the pandemic. There are no population-based data available on incident stroke in individuals with COVID-19. SUMMARY: In this review, we report on increased rates and severe prognosis of ischemic stroke among individuals with COVID-19, probably explained by hypercoagulability and inflammation, documented since the early phase of disease.We confirm the presence of falling rates of new ischemic stroke admissions in hospitals, probably due to social consequences of the pandemic: fear to be infected or not adequately treated in the hospital. This phenomenon is restricted to mild stroke and transient ischemic attacks.Short and long-term consequences of this trend of new strokes in the pandemic need to be evaluated

Coefficient of thermal expansion of nanostructured tungsten based coatings assessed by thermally induced substrate curvature method

The in plane coefficient of thermal expansion (CTE) and the residual stress of nanostructured W based coatings are extensively investigated. The CTE and the residual stresses are derived by means of an optimized ad-hoc developed experimental setup based on the detection of the substrate curvature by a laser system. The nanostructured coatings are deposited by Pulsed Laser Deposition. Thanks to its versatility, nanocrystalline W metallic coatings, ultra-nano-crystalline pure W and W-Tantalum coatings and amorphous-like W coatings are obtained. The correlation between the nanostructure, the residual stress and the CTE of the coatings are thus elucidated. We find that all the samples show a compressive state of stress that decreases as the structure goes from columnar nanocrystalline to amorphous-like. The CTE of all the coatings is higher than the one of the corresponding bulk W form. In particular, as the grain size shrinks, the CTE increases from 5.1 10$^{-6}$ K$^{-1}$ for nanocrystalline W to 6.6 10$^{-6}$ K$^{-1}$ in the ultra-nano-crystalline region. When dealing with amorphous W, the further increase of the CTE is attributed to a higher porosity degree of the samples. The CTE trend is also investigated as function of materials stiffness. In this case, as W coatings become softer, the easier they thermally expand.Comment: The research leading to these results has also received funding from the European Research Council Consolidator Grant ENSURE (ERC-2014-CoG No. 647554

Thermomechanical properties of amorphous metallic tungsten-oxygen and tungsten-oxide coatings

In this work, we investigate the correlation between morphology, composition, and the mechanical properties of metallic amorphous tungsten-oxygen and amorphous tungsten-oxide films deposited by Pulsed Laser Deposition. This correlation is investigated by the combined use of Brillouin Spectroscopy and the substrate curvature method. The stiffness of the films is strongly affected by both the oxygen content and the mass density. The elastic moduli show a decreasing trend as the mass density decreases and the oxygen-tungsten ratio increases. A plateaux region is detected in correspondence of the transition between metallic and oxide films. The compressive residual stresses, moderate stiffness and high local ductility that characterize compact amorphous tungsten-oxide films make them promising for applications involving thermal or mechanical loads. The coefficient of thermal expansion is quite high (i.e. 8.9 $\cdot$ 10$^{-6}$ K$^{-1}$), being strictly correlated to the amorphous structure and stoichiometry of the films. Under thermal treatments they show a quite low relaxation temperature (i.e. 450 K). They crystallize into the $\gamma$ monoclinic phase of WO$_3$ starting from 670 K, inducing an increase by about 70\% of material stiffness.Comment: The research leading to these results has also received funding from the European Research Council Consolidator Grant ENSURE (ERC-2014-CoG No. 647554). The views and opinions expressed herein do not necessarily reflect those of the European Commissio

Ultrasonic and Spectroscopic Techniques for the Measurement of the Elastic Properties of Nanoscale Materials

Materials at the nanoscale often have properties which differ from those they have in the bulk form. These properties significantly depend on the production process, and their measurement is not trivial. The elastic properties characterize the ability of materials to deform in a reversible way; they are of interest by themselves, and as indicators of the type of nanostructure. As for larger scale samples, the measurement of the elastic properties is more straightforward, and generally more precise, when it is performed by a deformation process which involves exclusively reversible strains. Vibrational and ultrasonic processes fulfill this requirement. Several measurement techniques have been developed, based on these processes. Some of them are suitable for an extension towards nanometric scales. Until truly supramolecular scales are reached, the elastic continuum paradigm remains appropriate for the description and the analysis of ultrasonic regimes. Some techniques are based on the oscillations of purpose-built testing structures, mechanically actuated. Other techniques are based on optical excitation and/or detection of ultrasonic waves, and operate either in the time domain or in the frequency domain. A comparative overview is given of these various techniques

Effects of lockdown on emergency room admissions for psychiatric evaluation: an observational study from the AUSL Romagna, Italy

Objectives: An observation of the admissions to the emergency room (ER) requiring psychiatric evaluation during the lockdown and investigation of the demographic and clinical variables. Methods: Retrospective longitudinal observational study of ER accesses for psychiatric evaluation was performed, comparing two periods (9 March–3 May 2020 vs. 9 March–3 May 2019). Data (number of admissions, key baseline demographic and clinical variables) were extracted from the ER databases of referral centres in a well-defined geographic area of North-Eastern Italy (Cesena, Ravenna, Forlì, and Rimini). Results: A 15% reduction of psychiatric referrals was observed, together with a 17% reduction in the total number of patients referring to the ER. This reduction was most evident in the first month of the lockdown period (almost 25% reduction of both referrals and patients). Female gender (OR: 1.52: 95%, CI: 1.12–2.06) and being a local resident (OR: 1.54: 95%CI: 1.02–2.34) were factors associated with the decrease. Conclusions: Lockdown changed dramatically health priorities in the local population, including people with mental health. We speculate that our observations do not only refer to the confinement due to the lockdown regime but also to fear of contagion and adoption of different coping strategies, especially in women.Key-points During lockdown 15% reduction of psychiatric visits and >17% reduction in the number of psychiatric patients referring to the ER was observed. in the first four weeks of the lockdown almost 25% reduction of both visits and patients was observed Female gender and being a local resident were factors associated with the decrease