3,905 research outputs found

    Torque-Controlled Stepping-Strategy Push Recovery: Design and Implementation on the iCub Humanoid Robot

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    One of the challenges for the robotics community is to deploy robots which can reliably operate in real world scenarios together with humans. A crucial requirement for legged robots is the capability to properly balance on their feet, rejecting external disturbances. iCub is a state-of-the-art humanoid robot which has only recently started to balance on its feet. While the current balancing controller has proved successful in various scenarios, it still misses the capability to properly react to strong pushes by taking steps. This paper goes in this direction. It proposes and implements a control strategy based on the Capture Point concept [1]. Instead of relying on position control, like most of Capture Point related approaches, the proposed strategy generates references for the momentum-based torque controller already implemented on the iCub, thus extending its capabilities to react to external disturbances, while retaining the advantages of torque control when interacting with the environment. Experiments in the Gazebo simulator and on the iCub humanoid robot validate the proposed strategy

    Direct Simulation Monte Carlo Method in Industrial Applications

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    In the present work three different applications of DSMC method to problems of industrial interest are revised and deepen by using both other methodologies and a more updated or advanced DSMC code, compared with those already used by other researchers to solve the same problems. For each problem, a preliminary rarefaction analysis verifies that the molecular approach, therefore the use of a DSMC code, is proper. More specifically, in this work the “sophisticated” DS2V (Ver.4.5) code has been used for the simulation of the flow fields in a deposition chamber and in a micro-channel as well as for the evaluation of viscosity of mixtures. The present work is an improvement of former works about the same topics because: 1) a method is proposed for the evaluation of the film distribution on the substrate. Furthermore, as the thin film deposition process is based on expanding thermal plasma from a torch, the influences of mass flow rate and of electrical power, supplied to the gas, and of the fluid-dynamic characteristics of the plasma jet, linked to geometry of different nozzles, are analyzed. 2) Some fluid-dynamic parameters in a micro-channel, such as load loss and impulse have been evaluated. 3) Computation of the exponent of the temperature viscosity law of a mixture of gases is proposed

    Long-term outcomes of direct acting antivirals in post-transplant advanced hepatitis C virus recurrence and fibrosing cholestatic hepatitis.

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    Long-term functional outcomes of sofosbuvir-based antiviral treatment were evaluated in a cohort study involving 16 Italian centres within the international compassionate use programme for post-transplant hepatitis C virus (HCV) recurrence. Seventy-three patients with cirrhosis (n=52) or fibrosing cholestatic hepatitis (FCH, n=21) received 24-week sofosbuvir with ribavirin\ub1pegylated interferon or interferon-free sofosbuvir-based regimen with daclatasvir/simeprevir+ribavirin. The patients were observed for a median time of 103 (82-112) weeks. Twelve of 73 (16.4%) died (10 non-FCH, 2 FCH) and two underwent re-LT. Sustained virological response was achieved in 46 of 66 (69.7%): 31 of 47 (66%) non-FCH and 15 of 19 (79%) FCH patients. All relapsers were successfully retreated. Comparing the data of baseline with last follow-up, MELD and Child-Turcotte-Pugh scores improved both in non-FCH (15.3\ub16.5 vs 10.5\ub13.8, P<.0001 and 8.4\ub12.1 vs 5.7\ub11.3, P<.0001, respectively) and FCH (17.3\ub15.9 vs 10.1\ub12.8, P=.001 and 8.2\ub11.6 vs 5.5\ub11, P=.001, respectively). Short-treatment mortality was higher in patients with baseline MELD 6525 than in those with MELD<25 (42.9% vs 4.8%, P=.011). Long-term mortality was 53.3% among patients with baseline MELD 6520 and 7.5% among those with MELD<20 (P<.0001). Among deceased patients 75% were Child-Turcotte-Pugh class C at baseline, while among survivors 83.9% were class A or B (P<.0001). Direct acting antivirals-based treatments for severe post-transplant hepatitis C recurrence, comprising fibrosing cholestatic hepatitis, significantly improve liver function, even without viral clearance and permit an excellent long-term survival. The setting of severe HCV recurrence may require the identification of "too-sick-to-treat patients" to avoid futile treatments

    Strumenti legimatici per la semplificazione e la valutazione della legislazione

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    Nel presente rapporto tecnico si verifica la possibilitĂ  di proporre alcuni strumenti automatici progettati nell'ambito dei progetti ITTIG al fini di incentivare la semplificazione e la valutzione della legislazione regional

    COVID-19 AdenoviralVector Vaccine and Central Retinal Vein Occlusion

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    Purpose: The purpose of this article is to report a case of sudden onset ischemic retinal central vein occlusion after a second dose of COVID-19 adenoviral vector vaccine.Case report/observations: A 54-year-old woman with systemic arterial hypertension developed ischemic central retinal vein occlusion in her right eye on day 2 after the second dose of COVID-19 adenoviral vector vaccine ChAdOx1 nCoV-19/AZD1222, Oxford-AstraZeneca.Conclusion: Adenoviral vector vaccine promotes both cellular and humoral immune responses, increasing the level of inflammatory cytokines. These cytokines are the same implied in the possible pathogenesis of central retinal vein occlusion. Subsequently, we recommend informing patients at risk of possible ocular adverse events, which require urgent evaluation
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