11 research outputs found

    A family of methods with arbitrary meshes for DFN flow simulations

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    A new approach for the simulation of the steady-state flow in discrete fracture networks is presented, along with new numerical results on complex configurations. The networks considered may have an arbitrary number of planar polygonal fractures with random spatial orientation, size and hydrological properties. The method is based on the minimization of a proper functional to enforce matching conditions at fracture intersections; the solution of the flow equations on each fracture of the network is carried on independently from the solution on the other fractures. Non-conforming Finite Element meshes on the fractures are allowed. Different discretization strategies can be used and mixed in order to improve approximation properties and provide high levels of accuracy. Extended Finite Elements and Virtual Elements have been successfully explored, thus a great flexibility is ensured when dealing with complex DFN configurations. The process for generating a suitable mesh is independently performed for each fracture, without requiring conformity at intersections, thus being extremely reliable and computationally inexpensive. The overall method is parallel oriented, thus providing an efficient handling of problem size and complexity. This is of paramount importance for massive simulations for uncertainty quantification in stochastically generated networks, or in the resolution of networks at very large scale and/or composed of even millions of fractures. The modular structure of the algorithm can easily embody other physical models for the description of flow regimes of increasing complexit

    A Parallel Solver for Large Scale DFN Flow Simulations

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    Cerebrospinal fluid lipoproteins inhibit α-synuclein aggregation by interacting with oligomeric species in seed amplification assays

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    Abstract Background Aggregation of α-synuclein (α-syn) is a prominent feature of Parkinson’s disease (PD) and other synucleinopathies. Currently, α-syn seed amplification assays (SAAs) using cerebrospinal fluid (CSF) represent the most promising diagnostic tools for synucleinopathies. However, CSF itself contains several compounds that can modulate the aggregation of α-syn in a patient-dependent manner, potentially undermining unoptimized α-syn SAAs and preventing seed quantification. Methods In this study, we characterized the inhibitory effect of CSF milieu on detection of α-syn aggregates by means of CSF fractionation, mass spectrometry, immunoassays, transmission electron microscopy, solution nuclear magnetic resonance spectroscopy, a highly accurate and standardized diagnostic SAA, and different in vitro aggregation conditions to evaluate spontaneous aggregation of α-syn. Results We found the high-molecular weight fraction of CSF (> 100,000 Da) to be highly inhibitory on α-syn aggregation and identified lipoproteins to be the main drivers of this effect. Direct interaction between lipoproteins and monomeric α-syn was not detected by solution nuclear magnetic resonance spectroscopy, on the other hand we observed lipoprotein-α-syn complexes by transmission electron microscopy. These observations are compatible with hypothesizing an interaction between lipoproteins and oligomeric/proto-fibrillary α-syn intermediates. We observed significantly slower amplification of α-syn seeds in PD CSF when lipoproteins were added to the reaction mix of diagnostic SAA. Additionally, we observed a decreased inhibition capacity of CSF on α-syn aggregation after immunodepleting ApoA1 and ApoE. Finally, we observed that CSF ApoA1 and ApoE levels significantly correlated with SAA kinetic parameters in n = 31 SAA-negative control CSF samples spiked with preformed α-syn aggregates. Conclusions Our results describe a novel interaction between lipoproteins and α-syn aggregates that inhibits the formation of α-syn fibrils and could have relevant implications. Indeed, the donor-specific inhibition of CSF on α-syn aggregation explains the lack of quantitative results from analysis of SAA-derived kinetic parameters to date. Furthermore, our data show that lipoproteins are the main inhibitory components of CSF, suggesting that lipoprotein concentration measurements could be incorporated into data analysis models to eliminate the confounding effects of CSF milieu on α-syn quantification efforts

    Blockage of interleukin-1β with canakinumab in patients with Covid-19

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    There is the urgent need to study the effects of immunomodulating agents as therapy for Covid-19. An observational, cohort, prospective study with 30 days of observation was carried out to assess clinical outcomes in 88 patients hospitalized for Covid-19 pneumonia and treated with canakinumab (300 mg sc). Median time from diagnosis of Covid-19 by viral swab to administration of canakinumab was 7.5 days (range 0–30, IQR 4–11). Median PaO2/FiO2 increased from 160 (range 53–409, IQR 122–210) at baseline to 237 (range 72–533, IQR 158–331) at day 7 after treatment with canakinumab (p < 0.0001). Improvement of oxygen support category was observed in 61.4% of cases. Median duration of hospitalization following administration of canakinumab was 6 days (range 0–30, IQR 4–11). At 7 days, 58% of patients had been discharged and 12 (13.6%) had died. Significant differences between baseline and 7 days were observed for absolute lymphocyte counts (mean 0.60 vs 1.11 × 109/L, respectively, p < 0.0001) and C-reactive protein (mean 31.5 vs 5.8 mg/L, respectively, p < 0.0001).Overall survival at 1 month was 79.5% (95% CI 68.7–90.3). Oxygen-support requirements improved and overall mortality was 13.6%. Confirmation of the efficacy of canakinumab for Covid-19 warrants further study in randomized controlled trials

    Prevalence, Pathogenesis and Management of Anemia in Inflammatory Bowel Disease: An IG-IBD Multicenter, Prospective, and Observational Study

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    Background: Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD), with a 6% to 74% prevalence and a negative impact on patient survival and quality of life, although the prevalence is apparently declining due to improved disease treatment. We aimed to investigate the prevalence, pathogenesis, and clinical correlates of anemia in Italian patients with IBD. Methods: A multicenter, prospective, observational study, involving 28 Italian gastroenterology centers, was conducted to investigate the epidemiology and consequences of IBD-associated anemia. Clinical and laboratory data of anemic patients were obtained at study enrolment. Results: Anemia was diagnosed in 737 of 5416 adult IBD outpatients (prevalence 13.6%); females were more commonly affected than males (odds ratio, 1.5; 95% confidence interval [CI], 1.2-1.7) and had more severe anemia. In the majority of cases, anemia was due to iron deficiency (62.5% of cases; 95% CI, 58.3%-66.6%), either isolated or in association with inflammation and/or vitamin deficiencies; anemia of inflammation accounted for only 8.3% of cases. More severe anemia was associated with increasing fatigue and worse quality of life. Only 68.9% of anemic patients with iron deficiency (95% CI, 63.4%-73.8%) and 34.6% of those with vitamin deficiencies (95% CI, 26.2%-44.2%) were properly treated with supplementation therapy. Conclusions: In Italy, the prevalence of IBD-associated anemia is lower than previously reported. Anemia of IBD is most commonly due to iron deficiency and contributes to fatigue and poor quality of life, but remains untreated in a large proportion of patients with iron and/or vitamin deficiencies. This study is registered at clinicaltrials.gov as NCT02872376

    The Imaging X-ray Polarimetry Explorer (IXPE): technical overview

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    Oncoplastic and reconstructive surgery in SENONETWORK Italian breast centers: lights and shadows

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    Metis: the Solar Orbiter visible light and ultraviolet coronal imager

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    Aims. Metis is the first solar coronagraph designed for a space mission and is capable of performing simultaneous imaging of the off-limb solar corona in both visible and UV light. The observations obtained with Metis aboard the Solar Orbiter ESA-NASA observatory will enable us to diagnose, with unprecedented temporal coverage and spatial resolution, the structures and dynamics of the full corona in a square field of view (FoV) of ±2.9° in width, with an inner circular FoV at 1.6°, thus spanning the solar atmosphere from 1.7 R⊙ to about 9 R⊙, owing to the eccentricity of the spacecraft orbit. Due to the uniqueness of the Solar Orbiter mission profile, Metis will be able to observe the solar corona from a close (0.28 AU, at the closest perihelion) vantage point, achieving increasing out-of-ecliptic views with the increase of the orbit inclination over time. Moreover, observations near perihelion, during the phase of lower rotational velocity of the solar surface relative to the spacecraft, allow longer-term studies of the off-limb coronal features, thus finally disentangling their intrinsic evolution from effects due to solar rotation. Methods. Thanks to a novel occultation design and a combination of a UV interference coating of the mirrors and a spectral bandpass filter, Metis images the solar corona simultaneously in the visible light band, between 580 and 640 nm, and in the UV H 
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