115 research outputs found
Strong convergence of solutions to nonautonomous Kolmogorov equations
We study a class of nonautonomous, linear, parabolic equations with unbounded
coefficients on which admit an evolution system of measures. It
is shown that the solutions of these equations converge to constant functions
as . We further establish the uniqueness of the tight evolution
system of measures and treat the case of converging coefficients
Compactness and invariance properties of evolution operators associated with Kolmogorov operators with unbounded coefficients
In this paper we consider nonautonomous elliptic operators
with nontrivial potential term defined in , where is a
right-halfline (possibly ). We prove that we can associate an
evolution operator with in the space of all bounded
and continuous functions on . We also study the compactness
properties of the operator . Finally, we provide sufficient conditions
guaranteeing that each operator preserves the usual -spaces and
Focused ultrasound to diagnose HIV-associated tuberculosis (FASH) in the extremely resource-limited setting of South Sudan: a cross-sectional study
Our cross-sectional study aimed at evaluating the diagnostic performance of Focused Assessment with Sonography for HIV-associated tuberculosis (FASH) to detect extrapulmonary tuberculosis in extremely resource-limited settings, with visceral leishmaniasis as a differential diagnosis with overlapping sonographic feature
Cardiovascular Risk Prediction in Ankylosing Spondylitis: From Traditional Scores to Machine Learning Assessment
Abstract Introduction The performance of seven cardiovascular (CV) risk algorithms is evaluated in a multicentric cohort of ankylosing spondylitis (AS) patients. Performance and calibration of traditional CV predictors have been compared with the novel paradigm of machine learning (ML). Methods A retrospective analysis of prospectively collected data from an AS cohort has been performed. The primary outcome was the first CV event. The discriminatory ability of the algorithms was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC), which is like the concordance-statistic (c-statistic). Three ML techniques were considered to calculate the CV risk: support vector machine (SVM), random forest (RF), and k-nearest neighbor (KNN). Results Of 133 AS patients enrolled, 18 had a CV event. c-statistic scores of 0.71, 0.61, 0.66, 0.68, 0.66, 0.72, and 0.67 were found, respectively, for SCORE, CUORE, FRS, QRISK2, QRISK3, RRS, and ASSIGN. AUC values for the ML algorithms were: 0.70 for SVM, 0.73 for RF, and 0.64 for KNN. Feature analysis showed that C-reactive protein (CRP) has the highest importance, while SBP and hypertension treatment have lower importance. Conclusions All of the evaluated CV risk algorithms exhibit a poor discriminative ability, except for RRS and SCORE, which showed a fair performance. For the first time, we demonstrated that AS patients do not show the traditional ones used by CV scores and that the most important variable is CRP. The present study contributes to a deeper understanding of CV risk in AS, allowing the development of innovative CV risk patient-specific models
Mepolizumab for Eosinophilic Granulomatosis With Polyangiitis: A European Multicenter Observational Study.
OBJECTIVE: Mepolizumab proved to be an efficacious treatment for eosinophilic granulomatosis with polyangiitis (EGPA) at a dose of 300 mg every 4âweeks in the randomized, controlled MIRRA trial. In a few recently reported studies, successful real-life experiences with the approved dose for treating severe eosinophilic asthma (100 mg every 4âweeks) were observed. We undertook this study to assess the effectiveness and safety of mepolizumab 100 mg every 4âweeks and 300 mg every 4âweeks in a large European EGPA cohort. METHODS: We included all patients with EGPA treated with mepolizumab at the recruiting centers in 2015-2020. Treatment response was evaluated from 3 months to 24 months after initiation of mepolizumab. Complete response to treatment was defined as no disease activity (Birmingham Vasculitis Activity Score [BVAS] = 0) and a prednisolone or prednisone dose (or equivalent) of â€4 mg/day. Respiratory outcomes included asthma and ear, nose, and throat (ENT) exacerbations. RESULTS: Two hundred three patients, of whom 191 received a stable dose of mepolizumab (158 received 100 mg every 4âweeks and 33 received 300 mg every 4âweeks) were included. Twenty-five patients (12.3%) had a complete response to treatment at 3 months. Complete response rates increased to 30.4% and 35.7% at 12 months and 24 months, respectively, and rates were comparable between mepolizumab 100 mg every 4âweeks and 300 mg every 4âweeks. Mepolizumab led to a significant reduction in BVAS score, prednisone dose, and eosinophil counts from 3 months to 24 months, with no significant differences observed between 100 mg every 4âweeks and 300 mg every 4âweeks. Eighty-two patients (40.4%) experienced asthma exacerbations (57 of 158 [36%] who received 100 mg every 4âweeks; 17 of 33 [52%] who received 300 mg every 4âweeks), and 31 patients (15.3%) experienced ENT exacerbations. Forty-four patients (21.7%) experienced adverse events (AEs), most of which were nonserious AEs (38 of 44). CONCLUSION: Mepolizumab at both 100 mg every 4âweeks and 300 mg every 4âweeks is effective for the treatment of EGPA. The 2 doses should be compared in the setting of a controlled trial
Functional impairment of systemic scleroderma patients with digital ulcerations: Results from the DUO registry
Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry
Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase
Connessione di un impianto eolico off-shore alla rete di trasmissione nazionale: valutazione delle problematiche e simulazioni dinamiche
In questo elaborato si sono studiati i principali aspetti e problematiche per la connessione di un parco eolico off-shore alla rete di trasmissione nazionale. Il parco eolico Ăš composto da 35 aerogeneratori di grossa taglia (3,6 MW ciascuno) per un totale di 126 MW nominali. Tramite una stazione di trasformazione a mare la tensione Ăš portata a 150 kV, tensione con la quale si trasmette lâenergia elettrica attraverso un cavo lungo 47,3 km. Adottando una trasmissione in corrente alternata il cavo puĂČ essere fonte di criticitĂ . Gli aerogeneratori inoltre sono del tipo a velocitĂ variabile con un convertitore di frequenza che li interfaccia alla rete. Tale convertitore Ăš lâelemento elettrico chiave che implementa i controlli sia nel funzionamento normale che in funzionamento perturbato. Per verificare le condizioni di normale esercizio dapprima si Ăš impostata una rete e fatte simulazioni dei flussi di potenza con il programma di simulazione numerica per reti elettriche NeplanÂź. Queste simulazioni hanno permesso di avere unâidea delle grandezze in gioco e non hanno evidenziato problemi particolari. Successivamente, con un modello dellâaerogeneratore fornito dal costruttore, sono state eseguite simulazioni statiche e dinamiche con il programma DIgSILENT PowerFactoryÂź, analogo a Neplan. Nelle simulazioni statiche (flussi di potenza) sono stati considerati principalmente i modi di regolazione del convertitore di frequenza ed Ăš stata elaborata una proposta di compensazione reattiva. Nelle simulazioni dinamiche si Ăš considerata la stabilitĂ dellâaerogeneratore in caso di guasto e il comportamento del convertitore, che permette anche un supporto della rete in caso di corto circuiti. Si Ăš verificato cosĂŹ che lâimpianto puĂČ rispettare le principali prescrizioni richieste da Terna per la connessione alla rete di trasmission
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