2,598 research outputs found
Long-term prediction of adherence to continuous positive air pressure therapy for the treatment of moderate/severe obstructive sleep apnea syndrome
BACKGROUND: Continuous positive airway pressure (CPAP) therapy is a highly effective treatment for obstructive sleep apnea syndrome (OSAS). However, poor adherence is a limiting factor, and a significant proportion of patients are unable to tolerate CPAP. The aim of this study was to determine predictors of long-term non-compliance with CPAP.
METHODS: CPAP treatment was prescribed to all consecutive patients with moderate or severe OSAS (AHI ≥15 events/h) (n = 295) who underwent a full-night CPAP titration study at home between February 1, 2002 and December 1, 2016. Adherence was defined as CPAP use for at least 4 h per night and five days per week. Subjects had periodical follow-up visits including clinical and biochemical evaluation and assessment of adherence to CPAP.
RESULTS: Median follow-up observation was 74.8 (24.2/110.9) months. The percentage of OSAS patients adhering to CPAP was 41.4% (42.3% in males and 37.0% in females), and prevalence was significantly higher in severe OSAS than in moderate (51.8% vs. 22.1%; p < 0.001; respectively). At multivariate analysis, lower severity of OSAS (HR = 0.66; CI 95 0.46-0.94) p < 0.023), cigarette smoking (HR = 1.72; CI 95 1.13-2.61); p = 0.011), and previous cardiovascular events (HR = 1.95; CI 95 1.03-3.70; p = 0.04) were the only independent predictors of long-term non-adherence to CPAP after controlling for age, gender, and metabolic syndrome.
CONCLUSIONS: In our cohort of patients with moderate/severe OSAS who were prescribed CPAP therapy, long-term compliance to treatment was present in less than half of the patients. Adherence was positively associated with OSAS severity and negatively associated with cigarette smoking and previous cardiovascular events at baseline
Role of stochastic noise and generalization error in the time propagation of neural-network quantum states
Neural-network quantum states (NQS) have been shown to be a suitable variational ansatz to simulate out-of-equilibrium dynamics in two-dimensional systems using time-dependent variational Monte Carlo (t-VMC). In particular, stable and accurate time propagation over long time scales has been observed in the square-lattice Heisenberg model using the Restricted Boltzmann machine architecture. However, achieving similar performance in other systems has proven to be more challenging. In this article, we focus on the two-leg Heisenberg ladder driven out of equilibrium by a pulsed excitation as a benchmark system. We demonstrate that unmitigated noise is strongly amplified by the nonlinear equations of motion for the network parameters, which causes numerical instabilities in the time evolution. As a consequence, the achievable accuracy of the simulated dynamics is a result of the interplay between network expressiveness and measures required to remedy these instabilities. We show that stability can be greatly improved by appropriate choice of regularization. This is particularly useful as tuning of the regularization typically imposes no additional computational cost. Inspired by machine learning practice, we propose a validation-set based diagnostic tool to help determining optimal regularization hyperparameters for t-VMC based propagation schemes. For our benchmark, we show that stable and accurate time propagation can be achieved in regimes of sufficiently regularized variational dynamics
Development and Implementation of the AIDA International Registry for Patients with Non-Infectious Scleritis
Integrazione di rilievi batimetrici e laser scanner aereo nell'area dei Colli Albani
The Colli Albani are a Quaternary volcanic complex located about 15 km SE of Rome, comprised
in an area of latitudes 41.6-41.9 N and longitudes 12.5-12.9 E. It has recently developed particular
interest in the geophysical community for some peculiar characteristics imputable to a residual
volcanic activity.
In the framework of a project financed by the Department of the Civil Protection devoted to the
study of the Colli Albani deformations, we have recently realized a bathymetric survey of the
Albano lake and an airborne laser scanner survey of the Albano and Nemi craters.
The present work is composed by two phases. In a first phase the accuracy of the DEM achieved by
the laser scanner is verified through a comparison with a GPS kinematic survey. In particular, our
aim is to test if the use of DEM in different formats, TIN or Grid, could lead to meaningful
differences in terms of accuracy and precision. In a second phase of the work, we merged the
LIDAR and bathymetric data with the purpose to achieve a complete digital terrain model of the
area that could allow in the next future geo-morphological analyses of the whole volcanic structure
Evaluating visitor experiences with interactive art
The Music Room is an interactive installation that allows visitor to compose classical music by moving throughout a space. The distance between them and their average speed maps the emotionality of music: in particular, distance influences the pleasantness of the music, while speed influences its intensity. This paper focuses on the evaluation of visitors' experience with The Music Room by examining log-data, video footages, interviews, and questionnaires, as collected in two public exhibitions of the installation. We examined this data to the identify the factors that fostered the engagement and to understand how players appropriated the original design idea. Reconsidering our design assumptions against behavioural data, we noticed a number of unexpected behaviours, which induced us to make some considerations on design and evaluation of interactive art
PVDF/BaTiO3 composite foams with high content of β phase by thermally induced phase separation (TIPS)
Poly(vinylidene fluoride) (PVDF) displays ferroelectric, piezoelectric and pyroelectric behavior and it is widely used in high-tech applications including sensors, transducers, energy harvesting devices and actuators. The crystallization of this polymer into highly polar β phase is desirable but is hard to achieve without applying specific thermo-mechanical treatments. Indeed, fabrication processes directly affect PVDF molecular chain conformation, inducing distinct polymorphs. In this paper, we present the fabrication of PVDF/BaTiO3 composite foams by thermally induced phase separation method (TIPS). Different compositions are tested and characterized. The crystallinity, and in particular the development of electroactive β crystal phase is monitored by FTIR, DSC and XRD measurements. Dielectric properties are also evaluated. It turns out that TIPS is a straightforward method that clearly promotes the spontaneous growth of the β phase in PVDF and its composite foams, without the need to apply additional treatments, and also significantly improves the degree of crystallinity. BaTiO3 content gives additional value to the development of β phase and total crystallinity of the systems. The low permittivity values (between 2 and 3), combined with the cellular morphology makes these materials suitable as lightweight components of microelectronic circuits
The imaging properties of the Gas Pixel Detector as a focal plane polarimeter
X-rays are particularly suited to probe the physics of extreme objects.
However, despite the enormous improvements of X-ray Astronomy in imaging,
spectroscopy and timing, polarimetry remains largely unexplored. We propose the
photoelectric polarimeter Gas Pixel Detector (GPD) as an instrument candidate
to fill the gap of more than thirty years of lack of measurements. The GPD, in
the focus of a telescope, will increase the sensitivity of orders of magnitude.
Moreover, since it can measure the energy, the position, the arrival time and
the polarization angle of every single photon, allows to perform polarimetry of
subsets of data singled out from the spectrum, the light curve or the image of
source. The GPD has an intrinsic very fine imaging capability and in this work
we report on the calibration campaign carried out in 2012 at the PANTER X-ray
test facility of the Max-Planck-Institut f\"ur extraterrestrische Physik of
Garching (Germany) in which, for the first time, we coupled it to a JET-X
optics module with a focal length of 3.5 m and an angular resolution of 18
arcsec at 4.5 keV. This configuration was proposed in 2012 aboard the X-ray
Imaging Polarimetry Explorer (XIPE) in response to the ESA call for a small
mission. We derived the imaging and polarimetric performance for extended
sources like Pulsar Wind Nebulae and Supernova Remnants as case studies for the
XIPE configuration, discussing also possible improvements by coupling the
detector with advanced optics, having finer angular resolution and larger
effective area, to study with more details extended objects.Comment: Accepted for publication in The Astrophysical Journal Supplemen
Inquinamento microbiologico delle sale operatorie: analisi critica di due decenni di sorveglianza
Obiettivo dello studio è stato quello di analizzare i risultati delle campagne di monitoraggio microbiologico delle sale operatorie effettuate negli ultimi due decenni presso il Policlinico di Roma, al fine di descrivere l’andamento nel tempo dei livelli di contaminazione riscontrati e di valutare eventuali cambiamenti significativi. Sono stati presi in esame i campionamenti microbiologici dell’aria effettuati all’interno di 14 blocchi operatori tra il 1992 ed il 2010. I risultati dei campionamenti sono stati aggregati in quattro periodi di tempo (1992-1996; 1996-2000; 2001-2005; 2006-2010) ed è stato analizzata la distribuzione nel tempo dei risultati dei campionamenti rispetto al limite proposto all'ISPESL per le sale at-rest (≤35 UFC/mc). La stessa analisi è stata ripetuta dopo la stratificazione per livello di rischio delle sale operatorie (AR e BR). Al fine di verificare il livello di significatività delle variazioni temporali nelle distribuzioni dei risultati si è fatto ricorso al test del x2 per il trend. Si è osservato un significativo trend in diminuzione del numero di sale con livelli di contaminazione superiori a quello indicato (x2 per trend=8,94; p<0,025). Tale riduzione ha riguardato soprattutto le sale operatorie AR (x2 per trend=7,33; p<0,05). I risultati ottenuti fanno ritenere che le misure adottate nelle sale ad AR siano risultate efficaci. Una maggiore attenzione dovrà essere posta alle sale operatorie a BR
Absence of FGFR3–TACC3 rearrangement in hematological malignancies with numerical chromosomal alteration
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