280 research outputs found

    Partial Regularity for Minimizers of Discontinuous Quasiconvex Integrals with general growth

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    We prove the partial Hölder continuity for minimizers of quasiconvex functionals F(u):=∫Ωf(x,u,Du)dx, where f satisfies a uniform VMO condition with respect to the x-variable and is continuous with respect to u. The growth condition with respect to the gradient variable is assumed a general one

    Poppies, Bloom

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    Risk factors for invasive aspergillosis in ICU patients with COVID-19: current insights and new key elements

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    Abstract Invasive pulmonary aspergillosis (IPA) has always been a challenging diagnosis and risk factors an important guide to investigate specific population, especially in Intensive Care Unit. Traditionally recognized risk factors for IPA have been haematological diseases or condition associated with severe immunosuppression, lately completed by chronic conditions (such as obstructive pulmonary disease, liver cirrhosis, chronic kidney disease and diabetes), influenza infection and Intensive Care Unit (ICU) admission. Recently, a new association with SARS-CoV2 infection, named COVID-19-associated pulmonary aspergillosis (CAPA), has been reported worldwide, even if its basic epidemiological characteristics have not been completely established yet. In this narrative review, we aimed to explore the potential risk factors for the development of CAPA and to evaluate whether previous host factors or therapeutic approaches used in the treatment of COVID-19 critically ill patients (such as mechanical ventilation, intensive care management, corticosteroids, broad-spectrum antibiotics, immunomodulatory agents) may impact this new diagnostic category. Reviewing all English-language articles published from December 2019 to December 2020, we identified 21 papers describing risk factors, concerning host comorbidities, ICU management, and COVID-19 therapies. Although limited by the quality of the available literature, data seem to confirm the role of previous host risk factors, especially respiratory diseases. However, the attention is shifting from patients’ related risk factors to factors characterizing the hospital and intensive care course, deeply influenced by specific features of COVID treatment itself. Prolonged invasive or non-invasive respiratory support, as well as the impact of corticosteroids and/or immunobiological therapies seem to play a pivotal role. ICU setting related factors, such as environmental factors, isolation conditions, ventilation systems, building renovation works, and temporal spread with respect to pandemic waves, need to be considered. Large, prospective studies based on new risk factors specific for CAPA are warranted to guide surveillance and decision of when and how to treat this particular population

    Power counting with one-pion exchange

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    Techniques developed for handing inverse-power-law potentials in atomic physics are applied to the tensor one-pion exchange potential to determine the regions in which it can be treated perturbatively. In S-, P- and D-waves the critical values of the relative momentum are less than or of the order of 400 MeV. The RG is then used to determine the power counting for short-range interaction in the presence of this potential. In the P-and D-waves, where there are no low-energy bound or virtual states, these interactions have half-integer RG eigenvalues and are substantially promoted relative to naive expectations. These results are independent of whether the tensor force is attractive or repulsive. In the 3S1 channel the leading term is relevant, but it is demoted by half an order compared to the counting for the effective-range expansion with only a short-range potential. The tensor force can be treated perturbatively in those F-waves and above that do not couple to P- or D-waves. The corresponding power counting is the usual one given by naive dimensional analysis.Comment: 18 pages, RevTeX (further details, explanation added

    Scattering from Singular Potentials in Quantum Mechanics

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    In non-relativistic quantum mechanics, singular potentials in problems with spherical symmetry lead to a Schrodinger equation for stationary states with non-Fuchsian singularities both as r tends to zero and as r tends to infinity. In the sixties, an analytic approach was developed for the investigation of scattering from such potentials, with emphasis on the polydromy of the wave function in the r variable. The present paper extends those early results to an arbitrary number of spatial dimensions. The Hill-type equation which leads, in principle, to the evaluation of the polydromy parameter, is obtained from the Hill equation for a two-dimensional problem by means of a simple change of variables. The asymptotic forms of the wave function as r tends to zero and as r tends to infinity are also derived. The Darboux technique of intertwining operators is then applied to obtain an algorithm that makes it possible to solve the Schrodinger equation with a singular potential containing many negative powers of r, if the exact solution with even just one term is already known.Comment: 19 pages, plain Tex. In this revised version, the analysis of Eq. (5.29) has been amended, and an appendix has been added for completenes

    Risk factors for liver decompensation and hcc in hcv-cirrhotic patients after daas: A multicenter prospective study

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    Background: Prospective studies on predictors of liver-related events in cirrhotic subjects achieving SVR after DAAs are lacking. Methods: We prospectively enrolled HCV cirrhotic patients in four Italian centers between November 2015 and October 2017. SVR and no-SVR cases were compared according to the presence or absence of liver-related events during a 24-month follow-up. Independent predictors of liver-related events were evaluated by Cox regression analysis. Results: A total of 706 subjects started DAAs therapy. SVR was confirmed in 687 (97.3%). A total of 61 subjects (8.9%) in the SVR group and 5 (26.3%) in the no-SVR group had liver-related events (p < 0.03). The incidence rate x 100 p/y was 1.6 for HCC, 1.7 for any liver decompensation, and 0.5 for hepatic death. Baseline liver stiffness (LSM) ≥ 20 kPa (HR 4.0; 95% CI 1.1–14.1) and genotype different from 1 (HR 7.5; 95% CI 2.1–27.3) were both independent predictors of liver decompensation. Baseline LSM > 20 KPa (HR 7.2; 95% CI 1.9–26.7) was the sole independent predictor of HCC. A decrease in liver stiffness (Delta LSM) by at least 20% at the end of follow-up was not associated with a decreased risk of liver-related events. Conclusion: Baseline LSM ≥ 20 kPa identifies HCV cirrhotic subjects at higher risk of liver-related events after SVR

    Interaction of alcohol intake and cofactors on the risk of cirrhosis.

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    OBJECTIVE: Evaluation of the interaction between alcohol intake and cofactors [hepatitis B virus (HBV), hepatitis C virus (HCV), body mass index] and coffee consumption on the risk of cirrhosis. DESIGN: Seven hundred and forty-nine consecutive patients with chronic liver disease referring to units for liver or alcohol diseases in Italy during a 6-months period. Teetotalers were excluded. The odds ratios (OR) for cirrhosis were evaluated using chronic hepatitis cases as the control group. RESULTS: An alcohol intake of more than 3 units/day resulted associated with the likelihood of cirrhosis both in males (OR 4.3; 95% CI=2.5-7.3) and in females (OR 5.7; 95% CI=2.3-14.5). A multiplicative interaction on the risk of cirrhosis between risky alcohol intake and HBsAg or HCV-Ab/HCV-RNA positivity was observed. A reduction of cirrhosis risk was observed in subjects consuming more than 3 alcohol units/day with increasing coffee intake. The OR for the association with cirrhosis decreased from 2.3 (95% CI=1.2-4.4) in subjects drinking 0-2 cups of coffee/day to 1.4 (95% CI=0.6-3.6) in those drinking more than 2 cups/day. CONCLUSIONS: In subjects with an alcohol intake >3 units/day the coexistence of HBV or HCV multiplies the risk of cirrhosis. Coffee represents a modulator of alcoholic cirrhosis risk
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