458 research outputs found

    Progettazione e sviluppo di una piattaforma per l'integrazione di software di simulazione in ambito nucleare

    Get PDF
    La tesi da noi proposta riguarda lo studio di fattibilità, la progettazione ed un primo prototipo di sviluppo di una piattaforma che permetta la semplificazione del processo di analisi in ambito nucleare. Il goal del nostro sistema consiste nel permettere agli utenti di poter gestire l’esecuzione delle simulazioni in maniera efficiente ed efficace tramite un’interfaccia user-friendly. Il sistema è in grado di integrarsi con i software pre-esistenti di calcolo e di simulazione utilizzati, interfacciandosi con essi al fine di completare il servizio

    On the thermal and thermodynamic (In)stability of methylammonium lead halide perovskites

    Get PDF
    The interest of the scientific community on methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) for hybrid organic-inorganic solar cells has grown exponentially since the first report in 2009. This fact is clearly justified by the very high efficiencies attainable (reaching 20% in lab scale devices) at a fraction of the cost of conventional photovoltaics. However, many problems must be solved before a market introduction of these devices can be envisaged. Perhaps the most important to be addressed is the lack of information regarding the thermal and thermodynamic stability of the materials towards decomposition, which are intrinsic properties of them and which can seriously limit or even exclude their use in real devices. In this work we present and discuss the results we obtained using non-ambient X-ray diffraction, Knudsen effusion-mass spectrometry (KEMS) and Knudsen effusion mass loss (KEML) techniques on MAPbCl3, MAPbBr3 and MAPbI3. The measurements demonstrate that all the materials decompose to the corresponding solid lead (II) halide and gaseous methylamine and hydrogen halide, and the decomposition is well detectable even at moderate temperatures (~60 °C). Our results suggest that these materials may be problematic for long term operation of solar devices

    Switch to maraviroc with darunavir/r, both QD, in patients with suppressed HIV-1 was well tolerated but virologically inferior to standard antiretroviral therapy: 48-Week results of a randomized trial

    Get PDF
    Objectives Primary study outcome was absence of treatment failure (virological failure, VF, or treatment interruption) per protocol at week 48. Methods Patients on 3-drug ART with stable HIV-1 RNA <50 copies/mL and CCR5-tropic virus were randomized 1:1 to maraviroc with darunavir/ritonavir qd (study arm) or continue current ART (continuation arm).Results In June 2015, 115 patients were evaluable for the primary outcome (56 study, 59 continuation arm). The study was discontinued due to excess of VF in the study arm (7 cases, 12.5%, vs 0 in the continuation arm, p = 0.005). The proportion free of treatment failure was 73.2% in the study and 59.3% in the continuation arm. Two participants in the study and 10 in the continuation arm discontinued therapy due to adverse events (p = 0.030). At VF, no emergent drug resistance was detected. Co-receptor tropism switched to non-R5 in one patient. Patients with VF reported lower adherence and had lower plasma drug levels. Femoral bone mineral density was significantly improved in the study arm. Conclusion Switching to maraviroc with darunavir/ritonavir qd in virologically suppressed patients was associated with improved tolerability but was virologically inferior to 3-drug therap

    4,4′,4′′-(Benzene-1,3,5-triyltris(ethyne-2,1-diyl))tris(1-methylpyridin-1-ium) Iodide

    Get PDF
    Despite having been known for a long time, quaternary 4,40-bipyridinium salts, or viologens, are still a highly inspiring class of compounds, thanks to their peculiar redox and charge transfer properties. However, more complex structures containing multiple pyridinium rings, also interspaced by conjugated moieties, allow an even wider synthetic variability and tunability of their characteristics. The compound described herein is a star-shaped, fully conjugated molecule with three methylated pyridinium rings connected by a triple bond spacer to a central benzene core, which was synthesized from readily available building blocks, representing a quite simple model of multi-pyridyl extended viologen; its UV–visible absorption and fluorescence spectra have also been investigated

    ANMCO/ELAS/SIBioC Consensus Document: Biomarkers in heart failure

    Get PDF
    Biomarkers have dramatically impacted the way heart failure (HF) patients are evaluated and managed. A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biological or pathogenic processes, or pharmacological responses to a therapeutic intervention. Natriuretic peptides [B-type natriuretic peptide (BNP) and N-terminal proBNP] are the gold standard biomarkers in determining the diagnosis and prognosis of HF, and a natriuretic peptide-guided HF management looks promising. In the last few years, an array of additional biomarkers has emerged, each reflecting different pathophysiological processes in the development and progression of HF: myocardial insult, inflammation, fibrosis, and remodelling, but their role in the clinical care of the patient is still partially defined and more studies are needed before to be well validated. Moreover, several new biomarkers have the potential to identify patients with early renal dysfunction and appear to have promise to help the management cardio-renal syndrome. With different biomarkers reflecting HF presence, the various pathways involved in its progression, as well as identifying unique treatment options for HF management, a closer cardiologist-laboratory link, with a multi-biomarker approach to the HF patient, is not far ahead, allowing the unique opportunity for specifically tailoring care to the individual pathological phenotype

    Thromboembolic event rate in paroxysmal and persistent atrial fibrillation: Data from the GISSI-AF trial

    Get PDF
    BACKGROUND: Few data on the thromboembolic (TE) risk of paroxysmal and persistent atrial fibrillation (AF) are available. This study aimed to assess the incidence of TE events in paroxysmal and persistent AF. METHODS: We performed a subset post hoc analysis of 771 patients with paroxysmal and 463 with persistent AF enrolled in the multicenter, prospective, randomized, double-blind, placebo-controlled GISSI-AF trial - comparing the efficacy of valsartan versus placebo in preventing AF recurrences – where the choice of antithrombotic treatment was left to the judgment of the referring physician. TE and major outcome events were centrally validated. AF recurrences were detected by frequent clinic visits and a transtelephonic monitoring device with weekly and symptomatic transmissions. RESULTS: Eighty-five percent of patients had a history of hypertension, and the 7.7% had heart failure, left ventricular dysfunction, or both. The mean CHADS(2) score was 1.41±0.84. TE and major bleeding events were observed at a low incidence among the overall population at 1-year follow-up (0.97% and 0.81%, respectively). The univariate and multivariable analyses revealed no statistically significant differences in the incidence of TE, major bleeding events or mortality in paroxysmal and persistent AF patients. TE events were more common among women than men (p=0.02). The follow-up examination showed under- or overtreatment with warfarin in many patients, according to guideline suggestions. Warfarin was more frequently prescribed to patients with persistent AF (p<0.0001) and patients with AF recurrences (p<0.0001). AF recurrences were noninvasively detected in 632 (51.2%) patients. In patients without AF recurrences, the TE event rate was 0.5% versus 1.74%, 1.28%, and 1.18% for those with only symptomatic, only asymptomatic or both symptomatic and asymptomatic AF recurrences, respectively, but the difference was not statistically significant, even after adjusting for warfarin treatment and the CHADS(2) score (HR 2.93; CI 95%; 0.8-10.9; p=0.11). CONCLUSIONS: TE and major bleeding events showed a very low incidence in the GISSI-AF trial population, despite under- or overtreatment with warfarin in many patients. TE events had a similar rate in paroxysmal and persistent AF. TRIAL REGISTRATION: Trial registration number: NCT0037627

    The free license codes as decision support system (DSS) for the emergency planning to simulate radioactive releases in case of accidents in the new generation energy plants

    Get PDF
    The radiological risk is related to a wide range of activities, beginning with the medical and military ones and including those connected to the industrial and research activities such as nuclear fusion. A valid tool to predict the consequences of the accidents and reduce the risk is represented by computing systems that allow modeling the evolution of a possible release of radioactive materials over time and space. In addition to proprietary codes there are free license codes, like Hot-Spot, that allow providing a set of tools to simulate diffusion in case of accidents involving radioactive materials and analyze the safety and security of the facilities in which the radioactive material is manipulated. The case studies scenario’s consists in two simulations accidents scenario the first to biomass plant and the second at nuclear fission plant. The simulation of the radioactive contamination have been conducted with the code HOT SPOT, a free license code. The results of the simulation and data discussion will be presented in this work by the authors

    An Evolutionary Algorithm for Automatic Recommendation of Clustering Methods and its Parameters

    Get PDF
    One of the main problems being faced at the time of performing data clustering consists in the deteremination of the best clustering method together with defining the ideal amount (k) of groups in which these data should be separated. In this paper, a preliminary approximation of a clustering recommender method is presented which, starting from a set of standardized data, suggests the best clustering strategy and also proposes an advisable k value. For this aim, the algorithm considers four indices for evaluating the final structure of clusters: Dunn, Silhouette, Widest Gap and Entropy. The prototype is implemented as a Genetic Algorithm in which individuals are possible configurations of the methods and their parameters. In this first prototype, the algorithm suggests between four partitioning methods namely K-means, PAM, CLARA and, Fanny. Also, the best set of parameters to execute the suggested method is obtained. The prototype was developed in an R environment, and its findings could be corroborated as consistent when compared with a combination of results provided by other methods with similar objectives. The idea of this prototype is to serve as the initial basis for a more complex framework that also incorporates the reduction of matrices with vast numbers of rows.Fil: Carballido, Jessica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Latini, Macarena Anahí. Universidad Nacional del Sur; ArgentinaFil: Ponzoni, Ignacio. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cecchini, Rocío Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentin
    corecore