Replicating Nanostructures on Silicon by Low Energy Ion Beams

We report on a nanoscale patterning method on Si substrates using self-assembled metal islands and low-energy ion-beam irradiation. The Si nanostructures produced on the Si substrate have a one-to-one correspondence with the self-assembled metal (Ag, Au, Pt) nanoislands initially grown on the substrate. The surface morphology and the structure of the irradiated surface were studied by high-resolution transmission electron microscopy (HRTEM). TEM images of ion-beam irradiated samples show the formation of sawtooth-like structures on Si. Removing metal islands and the ion-beam induced amorphous Si by etching, we obtain a crystalline nanostructure of Si. The smallest structures emit red light when exposed to a UV light. The size of the nanostructures on Si is governed by the size of the self-assembled metal nanoparticles grown on the substrate for this replica nanopatterning. The method can easily be extended for tuning the size of the Si nanostructures by the proper choice of the metal nanoparticles and the ion energy in ion-irradiation. It is suggested that off-normal irradiation can also be used for tuning the size of the nanostructures.Comment: 12 pages, 7 figures, regular paper submitted to Nanotechnolog

Safety profile of enhanced thromboprophylaxis strategies for critically ill COVID-19 patients during the first wave of the pandemic: observational report from 28 European intensive care units

Introduction: Critical illness from SARS-CoV-2 infection (COVID-19) is associated with a high burden of pulmonary embolism (PE) and thromboembolic events despite standard thromboprophylaxis. Available guidance is discordant, ranging from standard care to the use of therapeutic anticoagulation for enhanced thromboprophylaxis (ET). Local ET protocols have been empirically determined and are generally intermediate between standard prophylaxis and full anticoagulation. Concerns have been raised in regard to the potential risk of haemorrhage associated with therapeutic anticoagulation. This report describes the prevalence and safety of ET strategies in European Intensive Care Unit (ICUs) and their association with outcomes during the first wave of the COVID pandemic, with particular focus on haemorrhagic complications and ICU mortality. Methods: Retrospective, observational, multi-centre study including adult critically ill COVID-19 patients. Anonymised data included demographics, clinical characteristics, thromboprophylaxis and/or anticoagulation treatment. Critical haemorrhage was defined as intracranial haemorrhage or bleeding requiring red blood cells transfusion. Survival was collected at ICU discharge. A multivariable mixed effects generalised linear model analysis matched for the propensity for receiving ET was constructed for both ICU mortality and critical haemorrhage. Results: A total of 852 (79% male, age 66 [37\u201385] years) patients were included from 28 ICUs. Median body mass index and ICU length of stay were 27.7 (25.1\u201330.7) Kg/m2 and 13 (7\u201322) days, respectively. Thromboembolic events were reported in 146 patients (17.1%), of those 78 (9.2%) were PE. ICU mortality occurred in 335/852 (39.3%) patients. ET was used in 274 (32.1%) patients, and it was independently associated with significant reduction in ICU mortality (log odds = 0.64 [95% CIs 0.18\u20131.1; p = 0.0069]) but not an increased risk of critical haemorrhage (log odds = 0.187 [95%CI 12 0.591 to 12 0.964; p = 0.64]). Conclusions: In a cohort of critically ill patients with a high prevalence of thromboembolic events, ET was associated with reduced ICU mortality without an increased burden of haemorrhagic complications. This study suggests ET strategies are safe and associated with favourable outcomes. Whilst full anticoagulation has been questioned for prophylaxis in these patients, our results suggest that there may nevertheless be a role for enhanced / intermediate levels of prophylaxis. Clinical trials investigating causal relationship between intermediate thromboprophylaxis and clinical outcomes are urgently needed

Riflessioni sulla matematica di C.S. Peirce

Dopo un breve inquadramento di Peirce nella storia della matematica e della logica, l'articolo analizza la posizione del filosofo americano sulla natura della matematica e della logica e sul ruolo che queste discipline giocano nel sistema enciclopedico delle scienze

Medicina e classificazione delle scienze

Nell'articolo si esamina il problema della collocazione della medicina nella classificazione delle scienze tra Seicento e Ottocento. Sono prese in considerazione le proposte di organizzazione del sapere, e del posto in esse assegnato alla medicina, da parte dei filosofi F. Bacon, R. Descartes, Chr. Wolff, dello scienziato A.-M. Amp\ue8re, del medico H. Boerhaave con riferimento alla classificazione della medicina, e dalle sistemazioni presentate nell'Encyclopaedia di J.H. Alsted e nell'Encyclop\ue9die curata da D. Diderot e J. D'Alembert. Si precisa che sono stati scritti da A. Moretto l'Introduzione e i \ua7\ua7 3, 4

Teachers\u2019 attitudes towards students with disabilities: the role of the type of information provided in the students\u2019 profiles of children with disabilities

Teachers\u2019 attitudes towards students with disabilities have a crucial role in the effective implementation of the school inclusion process. This study examined the relationship of relevant teachers\u2019 personal variables (gender, age, length of professional experience, and the grade of the school in which they teach), characteristics of the students with disabilities (type of disability, gender), and contextual factors (type of information provided in the students\u2019 profiles of children with disabilities) with teachers\u2019 attitudes towards students with disabilities. A sample of 336 mainstream Italian primary and secondary teachers was involved. Results showed that teachers\u2019 gender, age, and length of professional experience were not related to their attitudes. Secondary school teachers hold more negative attitudes related to the social acceptability of students with disabilities. More negative attitudes related to school performance towards boys and students with intellectual disability, and more negative attitudes related to social acceptability towards students with behaviour problems were found. Lastly, the type of information provided in the students\u2019 profiles of children with disabilities positively impacted teachers\u2019 attitudes towards the students when the descriptions focused on their strengths. Implications of the results are discussed in terms of promoting teachers\u2019 positive attitudes towards students with disabilities

Prassi e conoscenza in medicina.

Il volume prende in esame il rapporto tra la cura e i concetti di salute, benessere, dolore, comunicazione, alleanza con particolare riferimento agli aspetti etici e al mind/body problem. Fa parte dei prodotti della ricerca del PRIN 2010-11 "La riflessione morale di fronte al mind/body problem. Problemi storici e prospettive teoriche" (Cofinanziamento MIUR - Dipartimento di Filosofia, Pedagogia e Psicologia dell'Universit\ue0 degli Studi di Verona), coordinatore nazionale: Franco Biasutti; responsabile locale: Giorgio Erle