1,122 research outputs found

    Commentary: Coordinated infraslow neural and cardiac oscillations mark fragility and offline periods in mammalian sleep.

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    We read with interest the paper by Lecci et al. (2017), who showed oscillations of the electroencephalographic (EEG) spectral power in the sigma band (10\u201315 Hz) during non-rapid-eye-movement (NREM) sleep at frequencies in the infra-slow range (ISO = 0.001\u20130.1 Hz). The occurrence of this rhythm (sigma-ISO) in human subjects and mice, and its correlation with autonomic and behavioral components suggest that it reflects a fundamental physiological mechanism

    Contribution of pulsars to cosmic-ray positrons in light of recent observation of inverse-Compton halos

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    The hypothesis that pulsar wind nebulae (PWNe) can significantly contribute to the excess of the positron (e+e^+) cosmic-ray flux has been consolidated after the observation of a γ\gamma-ray emission at TeV energies of a few degree size around Geminga and Monogem PWNe, and at GeV energies for Geminga at a much larger extension. The γ\gamma-ray halos around these PWNe are interpreted as due to electrons (e−e^-) and e+e^+ accelerated and escaped by their PWNe, and inverse Compton scattering low-energy photons of the interstellar radiation fields. The extension of these halos suggests that the diffusion around these PWNe is suppressed by two orders of magnitude with respect to the average in the Galaxy. We implement a two-zone diffusion model for the propagation of e+e^+ accelerated by the Galactic population of PWNe. We consider pulsars from the ATNF catalog and build up simulations of the PWN Galactic population. In both scenarios, we find that within a two-zone diffusion model, the total contribution from PWNe and secondary e+e^+ is at the level of AMS-02 data, for an efficiency of conversion of the pulsar spin down energy in e±e^\pm of η∼0.1\eta\sim0.1. For the simulated PWNe, a 1σ1\sigma uncertainty band is determined, which is of at least one order of magnitude from 10 GeV up to few TeV. The hint for a decreasing e+e^+ flux at TeV energies is found, even if it is strongly connected to the chosen value of the radius of the low diffusion bubble around each source.Comment: 10 pages, 7 figures. Figures 2, 3 and 5 updated. Results unchange

    Raltegravir, tenofovir, and emtricitabine in an HIV-Infected patient with HCV chronic hepatitis, NNRTI intolerance and protease inhibitors-induced severe liver toxicity

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    <p>Abstract</p> <p>Background</p> <p>in HIV-infected patients with HCV-related chronic hepatitis, liver impairment and drug toxicity may substantially reduce the number of possible therapeutic options.</p> <p>Case Description</p> <p>we here describe the case of an HCV-HIV coinfected woman who had repeated severe episodes of drug-related liver toxicity with indinavir, saquinavir, fosamprenavir, and darunavir, with minimal further therapeutic options left in this class. Previous treatment-limiting side effects with efavirenz and nevirapine also precluded use of non-nucleoside reverse transcriptase inhibitors. Introduction of an integrase-inhibitor regimen based on raltegravir, tenofovir, and emtricitabine allowed a prompt achievement of undetectable viral load and a substantial rise of CD4 count to high levels, with no subsequent episodes of hepatic toxicity, and no other side effects.</p> <p>Conclusions</p> <p>given the relatively common prevalence of HCV-related chronic hepatitis among people with HIV, raltegravir might represent an important alternative option for a substantial number of patients who cannot be treated with protease inhibitors or NNRTI because of drug-related hepatic toxicity.</p

    A Soft-Voting Ensemble Classifier for Detecting Patients Affected by COVID-19

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    COVID-19 is an ongoing global pandemic of coronavirus disease 2019, which may cause severe acute respiratory syndrome. This disease highlighted the limitations of health systems worldwide regarding managing the pandemic. In particular, the lack of diagnostic tests that can quickly and reliably detect infected patients has contributed to the spread of the virus. Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and antigen tests, which are the main diagnostic tests for COVID-19, showed their limitations during the pandemic. In fact, RT-PCR requires several hours to provide a diagnosis and is not properly accurate, thus generating a high number of false negatives. Unlike RT-PCR, antigen tests provide rapid diagnosis but are less accurate in detecting COVID-19 positive patients. Medical imaging is an alternative diagnostic test for COVID-19. In particular, chest computed tomography allows detecting lung infections related to the disease with high accuracy. However, visual analysis of a chest scan generated by computed tomography is a demanding activity for radiologists, making widespread use of this test unfeasible. Therefore, it is essential to lighten their work with automated tools able to provide accurate diagnosis in a short time. To deal with this challenge, in this work, an approach based on 3D Inception CNNs is proposed. Specifically, 3D Inception-V1 and Inception-V3 models have been built and compared. Then, soft-voting ensemble classifier models have been separately built on these models to boost the performance. As for the individual models, results showed that Inception-V1 outperformed Inception-V3 according to different measures. As for the ensemble classifier models, the outcome of experiments pointed out that the adopted voting strategy boosted the performance of individual models. The best results have been achieved enforcing soft voting on Inception-V1 models

    Sleep/wake rhythm modifications in the Italian population during SARS-CoV2 pandemic: a web-based cross-sectional survey.

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    Abstract. – OBJECTIVE: The study aims to investigate in a representative sample of the Italian population whether the SARS-CoV2 pandemic and the subsequent home isolation had repercussion on the daily sleep/wake cycling and habits. MATERIALS AND METHODS: A web-based cross-sectional survey consisted of various multiple-choice questions concerning demographic characteristics, sleep habits, and sleep-related problems was broadcast through mainstream social-media. Individuals were randomly allowed to participate from April 29th to May 17th, namely 50 days after the lockdown imposition and the day before its abrogation. RESULTS: 58.84% of respondents experienced a change in their sleep habits. 71% of those whose sleep changed showed a delayed sleep pattern. Overall, a two-fold risk of delayed sleep pattern without any change in total sleep time emerged during the investigation period. Females emerged almost 2 times more likely to modify their sleep habits than males. Youths were also more likely to experience modifications than old people, who conversely appeared protected. A significant improvement in daytime sleepiness occurred during the home isolation which additionally correlated with delayed bedtime and less sleep time. CONCLUSIONS: A high rate of change in sleep habits, especially among youths and females, occurred in Italian population during the home isolation to limit the SARS-CoV2 pandemic. Moreover, self-reported daytime sleepiness decreased in severity

    Free and forced wave motion in a two-dimensional plate with radial periodicity

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    In many practical engineering situations, a source of vibrations may excite a large and flexible structure such as a ship’s deck, an aeroplane fuselage, a satellite antenna, a wall panel. To avoid transmission of the vibration and structure-borne sound, radial or polar periodicity may be used. In these cases, numerical approaches to study free and forced wave propagation close to the excitation source in polar coordinates are desirable. This is the paper’s aim, where a numerical method based on Floquet-theory and the FE discretision of a finite slice of the radial periodic structure is presented and verified. Only a small slice of the structure is analysed, which is approximated using piecewise Cartesian segments. Wave characteristics in each segment are obtained by the theory of wave propagation in periodic Cartesian structures and Finite Element analysis, while wave amplitude change due to the changes in the geometry of the slice is accommodated in the model assuming that the energy flow through the segments is the same. Forced response of the structure is then evaluated in the wave domain. Results are verified for an infinite isotropic thin plate excited by a point harmonic force. A plate with a periodic radial change of thickness is then studied. Free waves propagation are shown, and the forced response in the nearfield is evaluated, showing the validity of the method and the computational advantage compared to FE harmonic analysis for infinite structures

    Cognitive Impairment and Age-Related Vision Disorders: Their Possible Relationship and the Evaluation of the Use of Aspirin and Statins in a 65 Years-and-Over Sardinian Population

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    Neurological disorders (Alzheimer’s disease, vascular and mixed dementia) and visual loss (cataract, age-related macular degeneration, glaucoma, and diabetic retinopathy) are among the most common conditions that afflict people of at least 65 years of age. An increasing body of evidence is emerging, which demonstrates that memory and vision impairment are closely, significantly, and positively linked and that statins and aspirin may lessen the risk of developing age-related visual and neurological problems. However, clinical studies have produced contradictory results. Thus, the intent of the present study was to reliably establish whether a relationship exist between various types of dementia and age-related vision disorders, and to establish whether statins and aspirin may or may not have beneficial effects on these two types of disorders. We found that participants with dementia and/or vision problems were more likely to be depressed and displayed worse functional ability in basic and instrumental activities of daily living than controls. Mini mental state examination scores were significantly lower in patients with vision disorders compared to subjects without vision disorders. A closer association with macular degeneration was found in subjects with Alzheimer’s disease than in subjects without dementia or with vascular dementia, mixed dementia, or other types of age-related vision disorders. When we considered the associations between different types of dementia and vision disorders and the use of statins and aspirin, we found a significant positive association between Alzheimer’s disease and statins on their own or in combination with aspirin, indicating that these two drugs do not appear to reduce the risk of Alzheimer’s disease or improve its clinical evolution and may, on the contrary, favor its development. No significant association in statin use alone, aspirin use alone, or the combination of these was found in subjects without vision disorders but with dementia, and, similarly, none in subjects with vision disorders but without dementia. Overall, these results confirm the general impression so far; namely, that macular degeneration may contribute to cognitive disorders (Alzheimer’s disease in particular). In addition, they also suggest that, while statin and aspirin use may undoubtedly have some protective effects, they do not appear to be magic pills against the development of cognitive impairment or vision disorders in the elderly
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