412 research outputs found

    Classical and quantum Big Brake cosmology for scalar field and tachyonic models

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    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical - quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong Big Bang and Big Crunch singularities are not traversable.Comment: final version, to appear in Phys. Rev.

    Immunomodulation in pediatric asthma

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    Childhood asthma is actually defined as a heterogeneous disease, including different clinical variants and partially sharing similar immune mechanisms. Asthma management is mainly focused on maintaining the control of the disease and reducing the risk of adverse outcomes. Most children achieve good control with standard therapies, such as low doses of inhaled corticosteroids (ICS) and/or one or more controller. These medications are targeted to suppress bronchial inflammation and to restore airway responsiveness. However, they are not disease-modifying and do not specifically target inflammatory pathways of asthma; in addition, they are not significantly effective in patients with severe uncontrolled asthma. The aim of this review is to update knowledge on current and novel therapeutic options targeted to immunomodulate inflammatory pathways underlying pediatric asthma, with particular reference on biologic therapies

    Food allergies: Current and future treatments

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    Food allergies are an increasingly public health problem, affecting up to 10% of children and causing a significant burden on affected patients, resulting in dietary restrictions, fear of accidental ingestion and related risk of severe reactions, as well as a reduced quality of life. Currently, there is no specific cure for a food allergy, so the only available management is limited to strict dietary avoidance, education on prompt recognition of symptoms, and emergency treatment of adverse reactions. Several allergen specific-and nonspecific-therapies, aiming to acquire a persistent food tolerance, are under investigation as potential treatments; however, to date, only immunotherapy has been identified as the most promising therapeutic approach for food allergy treatment. The aim of this review is to provide an updated overview on changes in the treatment landscape for food allergies

    A wearable heart rate measurement device for children with autism spectrum disorder

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    Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by early impairment in social and communication domains and autonomic nervous system unbalance. This study evaluated heart rate (HR) as a possible indicator of stress response in children with ASD as compared to children with language disorder (LD). Twenty-four patients [mean age = 42.62 months; SD = 8.14 months,12 with ASD (10 M/2F) and 12 with LD (8 M/4F)] underwent clinical [Leiter International Performance Scale-Revised, Autism Diagnostic Observation Schedule, second edition (ADOS-2)] and physiological evaluation (HR monitoring) during five interactive activities, while wearing an HR measurement device. IQ (ASD:IQ = 103.33 ± 12.85 vs. LD:IQ = 111.00 ± 8.88, p = 0.103) and fluid reasoning on the Leiter-R Scale were within the normal range in all subjects. Increased HR during the third activity (ADOS-2 bubble play) significantly correlated with autistic symptoms (r = 0.415; p = 0.044), while correlations between ADOS-2 total score and HR during the first activity (ADOS-2 free play; r = 0.368; p = 0.077), second activity (Leiter-R figure ground subscale; r = 0.373, p = 0.073), and fifth activity (ADOS-2 anticipation of a routine with objects; r = 0.368; p = 0.076) did not quite reach statistical significance. Applying a linear regression model, we found that the ADOS-2 total score significantly influenced HR variations (p = 0.023). HR monitoring may provide a better understanding of the stress-provoking situations for children with ASD. Furthermore, it could help clinicians detect the impact of the stressful condition on the autistic core and adress treatment strategy

    Soft Robotics. Bio-inspired Antagonistic Stiffening

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    Soft robotic structures might play a major role in the 4th industrial revolution. Researchers have demonstrated advantages of soft robotics over traditional robots made of rigid links and joints in several application areas including manufacturing, healthcare, and surgical interventions. However, soft robots have limited ability to exert larger forces and change their stiffness on demand over a wide range. Stiffness can be achieved as a result of the equilibrium of an active and a passive reaction force or of two active forces antagonistically collaborating. This paper presents a novel design paradigm for a fabric-based Variable Stiffness System including potential applications

    Towards Growing Robots: A Piecewise Morphology-Controller Co-adaptation Strategy for Legged Locomotion

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    Control of robots has largely been based on the assumption of a fixed morphology. Accordingly, robot designs have been stationary in time, except for the case of modular robots. Any drastic change in morphology, hence, requires a remodelling of the controller. This work takes inspiration from developmental robotics to present a piecewise morphology-controller growth/adaptation strategy that facilitates fast and reliable control adaptation to growing robots. We demonstrate our methodology on a simple 3 degree of freedom walking robot with adjustable foot lengths and with varying inertial conditions. Our results show not only the effectiveness and reliability of the piecewise morphology controller co-adaptation (PMCCA) strategy, but also highlight the need for morphological adaptation as a robot design strategy

    Use of remdesivir in children with covid-19 infection: A quick narrative review

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    SARS-CoV-2 infection has a severe course in a small percentage of children. Remdesivir has shown promising results in reducing hospitalisation time in adults, but data on mortality rate are conflicting and few studies are available on its use use in antivirals in children. We performed a quick narrative review of the available literature data regarding the usage of remdesivir in children and neonates. In children, remdesivir showed good safety profile, however bradicardia events have been reported in children. Remdesivir is cur-rently recommended by several guidelines in some subgroups of children with severe COVID-19, and should also be considered in critically ill patients, always in the context of the overall clinical picture and drug avail-ability. (www.actabiomedica.it)

    Biologic drugs in chronic spontaneous urticaria

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    Chronic spontaneous urticaria (CSU) is a condition defined by the presence of recurrent urticaria, angioedema, or both, which persist for more than six weeks in duration and occurs in the absence of an identifiable trigger. Both children and adults can develop CSU, although it is more common in adults and in women than in men, with a peak occurrence in the third to fifth decades of life. It imposes a significant burden on patients, families and healthcare systems. The goal of therapy in patients with CSU is to achieve a level of symptom control and improvement in quality of life that is acceptable to the patient, while minimizing therapy-related side effects. The recent introduction of biologic drugs has changed the management of the disease. This work aims to provide a narrative review of the current state of biological therapy and the promising drugs under development for CSU

    SPADA: A project to study the effectiveness of shielding materials in space

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    The SPADA (SPAce Dosimetry for Astronauts) project is a part of an extensive teamwork that aims to optimize shielding solutions against space radiation. Shielding is indeed an irreplaceable tool to reduce exposure of crews of future Moon and Mars missions. We concentrated our studies on two flexible materials, Kevlar R� and Nextel R,� because of their ability to protect human space infrastructures from micrometeoroids. We measured radiation hardness of these shielding materials and compared to polyethylene, generally acknowledged as the most effective space radiation shield with practical applications in spacecraft. Both flight test (on the International Space Station and on the Russian FOTON M3 rocket), with passive dosimeters and accelerator-based experiments have been performed. Accelerator tests using high-energy Fe ions have demonstrated that Kevlar is almost as effective as polyethylene in shielding heavy ions, while Nextel is a poor shield against high-charge and -energy particles. Preliminary results from spaceflight, however, show that for the radiation environment in low-Earth orbit, dominated by trapped protons, thin shields of Kevlar and Nextel provide limited reduction
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