408 research outputs found

    Hoffa’s fat pad thickness: a measurement method with sagittal MRI sequences

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    Background: Hoffa’s fat pad is a structure located within the fibrous joint capsule of the knee joint, but outside the synovial cavity. It plays an important biomechanical and metabolic role in knee joint, reducing the impact of forces generated by loading and producing cytokines. Changes in its size can induce modifications in the knee homeostasis. However, a great variability exists regarding its measurements. This work aims to evaluate the reliability of a measurement method of Hoffa’s fat pad dimensions through MRI. Methods: 3T sagittal IW 2D TSE fat-suppressed MRI sequences, taken from the OAI (Osteoarthritis initiative) database, of 191 male and female patients, aged between 40 and 80 years, were analysed; a manual measurement of the thickness of Hoffa’s fat pad of each subject was then performed by two different readers. The interobserver reliability and intraobserver reliability of the measurements were described by coefficient of variation (CV), Pearson correlation and Bland–Altman plots. Results: All statistical analyses have shown that not significant intra- or interobservers differences were evident (intraobserver CV % for the first observer was 2.17% for the right knee and 2.24% for the left knee, while for the second observer 2.31% for the right knee and 2.24% for the left knee; linear correlation was for the first observer r = 0.96 for the right knee and r = 0.96 for the left knee, while for the second observer r = 0.97 for the right knee and r = 0.96 for the left knee; in addition, the interobserver CV % was 1.25% for the right knee and 1.21% for the left knee and a high interobserver linear correlation was found: r = 0.97 for the right knee and r = 0.96 for the left knee). All results suggest that this manual measurement method of Hoffa’s fat pad thickness can be performed with satisfactory intra- and interobserver reliability. Conclusions: Hoffa’s fat pad thickness can be measured, using sagittal MRI images, with this manual method that represents, for his high reliability, an effective means for the study of this anatomical structure

    Adherence and Constancy in LIME-RS Explanations for Recommendation

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    Explainable Recommendation has attracted a lot of attention due to a renewed interest in explainable artificial intelligence. In particular, post-hoc approaches have proved to be the most easily applicable ones to increasingly complex recommendation models, which are then treated as black boxes. The most recent literature has shown that for post-hoc explanations based on local surrogate models, there are problems related to the robustness of the approach itself. This consideration becomes even more relevant in human-related tasks like recommendation. The explanation also has the arduous task of enhancing increasingly relevant aspects of user experience such as transparency or trustworthiness. This paper aims to show how the characteristics of a classical post-hoc model based on surrogates is strongly model-dependent and does not prove to be accountable for the explanations generatedThe authors acknowledge partial support of PID2019-108965GB-I00, PONARS01_00876BIO-D,CasadelleTecnologie mergenti della Cittàdi Matera, PONARS01_00821FLET4.0, PIAServiziLocali2.0,H2020Passapartout-Grantn. 101016956, PIAERP4.0,andIPZS-PRJ4_IA_NORMATIV

    What every doctor should know about drug safety in patients with chronic kidney disease

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    Drug safety is a very relevant issue when dealing with patients with chronic kidney disease (CKD) who need vascular access procedures and interventions. Drug dosage adjustments are needed for patients with acute or chronic kidney disease. In CKD patients, the estimated glomerular filtration rate is used to guide dose adjustments. Determining the influence of renal replacement therapies on drug dosage adjustment is also very important. Safety issues for the following drugs used for situations related to vascular access are reported: anticoagulants and antiplatelet agents, antibiotics, antimicrobials for catheter lock therapy, thrombolytics, local anesthetics, and painkillers. General principles of the interactions of drugs in CKD are also reported

    Two-pass two-way acceleration in a superconducting continuous wave linac to drive low jitter x-ray free electron lasers

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    We present a design study of an innovative scheme to generate high rep rate (MHz-class) GeV electron beams by adopting a two-pass two-way acceleration in a Superconducting (SC) linac operated in Continuous Wave (CW) mode. The electron beam is accelerated twice by being re-injected in opposite direction of propagation into the linac after the first passage. Acceleration in opposite directions is accomplished thanks to standing waves supported in RF cavities. The task of recirculating the electron beam when it leaves the linac after first pass is performed by a Bubble-shaped Arc Compressor composed by a sequence of Double Bend Achromat. In this paper we address the main issues inherent to the two-pass acceleration process and the preservation of the electron beam quality parameters (emittance, energy spread, peak current) required to operate X-ray Free Electron Lasers with low jitters in the amplitude, spectral and temporal domain, as achieved by operating in seeding and/or oscillator mode a CW FEL up to 1 MHz rep rate. Detailed start-to-end simulations are shown to assess the capability of this new scheme to double the electron beam energy as well as to compress the electron bunch length from picoseconds down to tens of femtoseconds. The advantage of such a scheme is to halve the requested linac length for the same final electron beam energy, which is typically in the few GeV range, as needed to drive an X-ray FEL. The AC power to supply the cryogenic plant is also significantly reduced with respect to a conventional single-pass SC linac for the same final energy. We are reporting also X-ray FEL simulations for typical values of wavelengths of interest (in the 200 eV \u2013 8 keV photon energy range) to better illustrate the potentiality of this new scheme

    A facility to Search for Hidden Particles (SHiP) at the CERN SPS

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    A new general purpose fixed target facility is proposed at the CERN SPS accelerator which is aimed at exploring the domain of hidden particles and make measurements with tau neutrinos. Hidden particles are predicted by a large number of models beyond the Standard Model. The high intensity of the SPS 400~GeV beam allows probing a wide variety of models containing light long-lived exotic particles with masses below O{\cal O}(10)~GeV/c2^2, including very weakly interacting low-energy SUSY states. The experimental programme of the proposed facility is capable of being extended in the future, e.g. to include direct searches for Dark Matter and Lepton Flavour Violation.Comment: Technical Proposa

    Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster

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    Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle θ13\theta_{13} in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small L/EL/E, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current νμ\nu_{\mu} disappearance tension with νe\nu_e appearance and disappearance at the eV mass scale. Instead, a new CERN neutrino beam would allow a further span in the parameter space together with a refined control of systematics and, more relevant, the measurement of the antineutrino sector, by upgrading the spectrometer with detectors currently under R&D study.Comment: 76 pages, 52 figure

    Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam

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    The OPERA experiment, exposed to the CERN to Gran Sasso νμ\nu_\mu beam, collected data from 2008 to 2012. Four oscillated ντ\nu_\tau Charged Current interaction candidates have been detected in appearance mode, which are consistent with νμντ\nu_\mu \to \nu_\tau oscillations at the atmospheric Δm2\Delta m^2 within the "standard" three-neutrino framework. In this paper, the OPERA ντ\nu_\tau appearance results are used to derive limits on the mixing parameters of a massive sterile neutrino.Comment: 11 pages, 4 figures; reference to Planck result updated in the Introduction. Submitted to JHE
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