5 research outputs found
A General Platform for the Modeling and Optimization of Conventional and More Electric Aircrafts
The present study aims at the implementation of a Matlab/Simulink environment to assess the performance (thrust, specific fuel consumption, aircraft/engine mass, cost, etc.) and environmental impact (greenhouse and pollutant emissions) of conventional and more electric aircrafts. In particular, the benefits of adopting more electric solutions for either aircrafts at given missions specifications can be evaluated.
The software, named PLA.N.E.S, includes a design workflow for the input of aircraft specification, kind of architecture (e.g. series or parallel) and for the definition of each component including energy converter (piston engine, turboprop, turbojet, fuel cell, etc.), energy storage system (batteries, super-capacitors), auxiliaries and secondary power systems. It is also possible to setup different energy management strategies for the optimal control of the energy flows among engine, secondary equipment and storage systems during the mission.
The tool is designed to be integrated with a multi-objective optimization environment. In the present investigation the tools has been applied to a regional airliner (ATR 72-600) as a case study and two options for the propulsion system were considered: conventional and More Electric Aircraft.
In order to validate the proposed turboprop model, the results obtained with PLA.N.E.S. were compared to nominal literature data and numerical values obtained with the Gas Turbine Simulation Program (GSP)
Alterazione delle difese monocito-mediate nei confronti di Cryptococcus neoformans in presenza dell’Herpesvirus umano 6
Alterazione delle difese monocito-mediate nei confronti di Cryptococcus neoformans in presenza dell’Herpesvirus umano 6Introduzione: I casi clinici di infezioni miste sono in aumento, specialmente in ospiti immunocompromessi, ma gli eventi biomolecolari che caratterizzano la patogenesi delle malattie polimicrobiche sono ancora scarsamente conosciuti. In un modello in vitro di infezione mista da Cryptococcus neoformans ed herpesvirus umano 6 (HHV-6), entrambi altamente neurotropi e causa di gravi patologie a livello del sistema nervoso centrale nel paziente immunocompromesso, abbiamo valutato le alterazioni funzionali del macrofago esposto alla doppia infezione.Materiali e Metodi: Cellule monocitiche THP-1 sono state esposte ad HHV-6 variante A (U1102), attraverso la co-coltura con cellule linfocitarie (linea JJHAN) infettate produttivamente (THP-1/JJHANHHV-6) o con cellule di controllo (THP-1/JJHANMOCK) per tempi diversi; successivamente, le co-colture sono state esposte a C. neoformans (isolato clinico ottenuto dal liquor di un paziente con meningite) e quindi saggiate per risposta secretoria (test ELISA) ed attività antimicrobica mediante valutazione della fagocitosi (allestimento di citopreparati opportunamente colorati) e dell’attività anticriptococcica (test di inibizione delle unità formanti colonia). Risultati: Rispetto ai controlli THP-1/JJHANMOCK, le co-colture THP-1/JJHANHHV-6 mostrano a) significativa produzione di IL-12 e IFN- che aumentano ulteriormente dopo infezione con C. neoformans; b) aumentata fagocitosi nei riguardi C. neoformans; c) scarsa ed invariata attività di killing a tempi brevi e d) ridotta capacità di contenere la crescita fungina a tempi successivi.Conclusioni: La presenza di HHV-6 altera la funzionalità macrofagica a vantaggio di C. neoformans facilitandone la localizzazione intracellulare e promuovendone la replicazione.(Fondi PRIN-2003)
New insights on collagen structural organization and spatial distribution around dental implants: a comparison between machined and laser-treated surfaces
Abstract Background One of the main factors for the osseointegration of dental implants is the development of an adequate soft tissue barrier, mainly composed by collagen, which protects the implant from bacterial development. The structural features of the peri-implant collagen are influenced by the implant components and, in particular, by the type of the surface. In the clinical practice, healing abutments are characterized by smooth surfaces, named machined. Recently, a new laser technique, Synthegra, has been developed to obtain a topography-controlled surface with micrometric regular pores that seems reducing the risk of peri-implantitis. Based on this background, this study aims investigating the structural organization and spatial distribution of collagen surrounding healing abutments characterized by laser-treated and machined surfaces. Methods Gingiva portions surrounding custom-made healing abutments (HA), characterized by alternated laser-treated and machined surfaces, were collected and analyzed by combining Fourier Transform InfraRed Imaging (FTIRI) spectroscopy, a non-invasive and high-resolution bidimensional analytical technique, with histological and multivariate analyses. Results Masson’s trichrome staining, specific for collagen, highlighted a massive presence of collagen in all the analyzed samples, evidencing a surface-related spatial distribution. The nature of collagen, investigated by the FTIRI spectroscopy, appeared more abundant close to the laser-treated surface, with a perpendicular disposition of the bundles respect to the HA; conversely, a parallel distribution was observed around the machined surface. A different secondary structure was also found, with a higher amount of triple helices and a lower quantity of random coils in collagen close to the laser treated surfaces. Conclusions FTIRI spectroscopy demonstrates that the use of a laser treated transmucosal surface can improve the morphological organization of the peri-implant collagen, which presents a distribution more similar to that of natural teeth. Trial registration: This trial is registered with ClinicalTrials.gov Identifier: (Registration Number: NCT05754970). Registered 06/03/2023, retrospectively registered, https://clinicaltrials.gov/show/NCT05754970
Human herpesvirus-6 dysregulates monocyte-ediated anticryptococcal defences.
In order to investigate the interplay occurring between pathogens in the course of double infections, we set up an in vitro model in which the monocytic cell line, THP-1, is exposed to Cryptococcus neoformans (Cn) and Human Herpesvirus 6 (HHV-6). Cn and HHV-6, both highly neurotropic, can cause serious diseases of the central nervous system and have monocytes, among other cell types, as target cells, causing alteration of their secretion pattern. Here, we show that, unlike THP-1 cells exposed to cell-free virus inocula, THP-1 exposed to HHV-6 producing lymphocytes exhibit augmented phagocytosis against Cn. The phenomenon occurs after 24 hours of monocyte/lymphocyte co-culture and it is independent of direct cell-to-cell contact. Moreover, in the presence of HHV-6, THP-1 cells express enhanced secretory responses but reduced capability to counteract fungal infection: the better ingestion by monocytes is followed by facilitated fungal survival and replication. These data provide initial in vitro evidence that HHV-6 may dysregulate monocyte-mediated anticryptococcal defences with an overall pro-cryptococcus result
Second asymptomatic carotid surgery trial (ACST-2) : a randomised comparison of carotid artery stenting versus carotid endarterectomy
Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.
Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.
Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86-1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91-1·32; p=0·21).
Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable