271 research outputs found

    Un point de vue italien

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    Dynamics and evolution of Turbulent Taylor rolls

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    In many shear- and pressure-driven wall-bounded turbulent flows secondary motions spontaneously develop and their interaction with the main flow alters the overall large-scale features and transfer properties. Taylor-Couette flow, the fluid motion developing in the gap between two concentric cylinders rotating at different angular velocity, is not an exception, and toroidal Taylor rolls have been observed from the early development of the flow up to the fully turbulent regime. In this manuscript we show that under the generic name of ``Taylor rolls'' there is a wide variety of structures that differ for the vorticity distribution within the cores, the way they are driven and their effects on the mean flow. We relate the rolls at high Reynolds numbers not to centrifugal instabilities, but to a combination of shear and anti-cyclonic rotation, showing that they are preserved in the limit of vanishing curvature and can be better understood as a pinned cycle which shows similar characteristics as the self-sustained process of shear flows. By analyzing the effect of the computational domain size, we show that this pinning is not a product of numerics, and that the position of the rolls is governed by a random process with the space and time variations depending on domain size.Comment: Submitted to JF

    A finite point method for compressible flow

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    This is the accepted version of the following article: [Löhner, R. , Sacco, C. , Oñate, E. and Idelsohn, S. (2002), A finite point method for compressible flow. Int. J. Numer. Meth. Engng., 53: 1765-1779. doi:10.1002/nme.334], which has been published in final form at https://onlinelibrary.wiley.com/doi/abs/10.1002/nme.334A weighted least squares finite point method for compressible flow is formulated. Starting from a global cloud of points, local clouds are constructed using a Delaunay technique with a series of tests for the quality of the resulting approximations. The approximation factors for the gradient and the Laplacian of the resulting local clouds are used to derive an edge-based solver that works with approximate Riemann solvers. The results obtained show accuracy comparable to equivalent mesh-based finite volume or finite element techniques, making the present finite point method competitive.Peer ReviewedPostprint (author's final draft

    Il concetto di interpretazione del diritto / Rodolfo Sacco

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    Il concetto di interpretazione del diritto / Rodolfo Sacco Torino : G. Giappichelli, stampa 1947 176 p. ; 25 cm

    Introduzione al diritto privato somalo : un paese africano inizia l'edificazione del socialismo / Rodolfo Sacco

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    Introduzione al diritto privato somalo : un paese africano inizia l'edificazione del socialismo / Rodolfo Sacco Torino : G. Giappichelli, stampa 1973 191 p. ; 26 cm

    La buona fede nella teoria dei fatti giuridici di diritto privato / Rodolfo Sacco

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    La buona fede nella teoria dei fatti giuridici di diritto privato / Rodolfo Sacco Torino : G. Giappichelli, stampa 1949 XII, 293 p. ; 25 cm

    Il potere di procedere in via surrogatoria : parte generale / Rodolfo Sacco

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    Il potere di procedere in via surrogatoria : parte generale / Rodolfo Sacco Torino : Giappichelli, 1955 XII, 327 p. ; 26 cm

    Endocuff-assisted versus Cap-assisted Colonoscopy in Increasing Adenoma Detection Rate. A Meta-analysis.

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    Background and Aims: Several add-on devices have been developed to increase rates of colon adenoma detection. We aimed to compare the endocuff-assisted colonoscopy with cap-assisted colonoscopy through a pairwise meta-analysis of randomized trials. Methods: We searched the PubMed/Medline and Embase database through March 2020 and identified 6 randomized controlled trials (comprising 2,027 patients). The primary outcome was adenoma detection rate; secondary outcomes included sessile serrated adenoma detection rate, mean adenoma per colonoscopy, cecal intubation rate and time to reach cecum. Safety data were also analyzed. We performed pairwise meta-analysis through a random effects model and expressed data as risk ratio and 95% confidence interval. Results: Overall, pooled adenoma detection rate was 48.1% (39.3-56.8%) with endocuff and 40.5% (30.4- 50.6%; risk ratio 1.14, 0.96-1.35) with cap. Proximal adenoma detection rate was 45.7% (36.8-54.7%) and 24% (17-45.1%) with endocuff and cap, respectively (risk ratio 2.04, 0.93-4.49), whereas endocuff outperformed cap-assisted colonoscopy in detecting diminutive (≤ 5 mm) adenomas (risk ratio 2.74, 1.53-4.90) and in terms of mean adenoma per colonoscopy (mean difference 0.31, 0.05 -0.57; p=0.02). Sessile serrated adenoma detection rate (risk ratio 1.36, 0.72-2.59), cecal intubation rate (risk ratio 0.99, 0.98-1.00), and time to reach cecum (6.87 min versus 6.87 min) were similar between the two groups. No serious adverse event was observed. Conclusion: Endocuff-assisted colonoscopy seems to provide a higher adenoma detection rate as compared to cap-assisted colonoscopy, in particular concerning smaller diminutive polyps

    Bismuth-based quadruple therapy following H. Pylori eradication failures: A multicenter study in clinical practice

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    Background & Aims: Helicobacter pylori (H. pylori) eradication in patients who failed one or more therapeutic attempts remains challenging. This study aimed to assess the efficacy of three-in-one capsules bismuth-based quadruple therapy (Pylera®) in these patients managed in clinical practice. Methods: This was a prospective, open-label, multicenter study enrolling consecutive, adult patients with persistent H. pylori infection following at least one standard therapy. All patients received a rescue quadruple therapy with Pylera (3 capsules four times daily) and esomeprazole 20 mg (1 tablet twice daily) for 10 days. H. pylori eradication was assessed by using Urea Breath Test 4-6 weeks following therapy ending. H. pylori eradication rates, compliance, and side-effects were calculated. Results: A total of 208 patients in the 9 participating centres were enrolled. Overall, 180 patients were successfully cured from the infection, accounting for 86.5% (95% CI 81.9-91.2) and 92.3% (95% CI 88.6-96.1) eradication rates at intention-to-treat analysis and at per protocol analysis, respectively. Cure rates were similar across patients who failed one to three previous therapy attempts, but the success rate fell to 67% after 4 or more therapy failures. Compliance to therapy was good in 198 (95.2%) patients, whilst in 7 (5.3%) cases the therapy was interrupted within 5 days due to side effects. A total of 97 (46.6%) patients complained of at least one side effect; nausea, diarrhea and vomiting were the most frequently reported. Conclusions: Our study found that this bismuth-based quadruple therapy is highly effective as second-line and rescue therapy for H. pylori eradication in clinical practic

    Bismuth-based quadruple therapy following H. Pylori eradication failures: A multicenter study in clinical practice

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    Background & Aims: Helicobacter pylori (H. pylori) eradication in patients who failed one or more therapeutic attempts remains challenging. This study aimed to assess the efficacy of three-in-one capsules bismuth-based quadruple therapy (Pylera®) in these patients managed in clinical practice. Methods: This was a prospective, open-label, multicenter study enrolling consecutive, adult patients with persistent H. pylori infection following at least one standard therapy. All patients received a rescue quadruple therapy with Pylera (3 capsules four times daily) and esomeprazole 20 mg (1 tablet twice daily) for 10 days. H. pylori eradication was assessed by using Urea Breath Test 4-6 weeks following therapy ending. H. pylori eradication rates, compliance, and side-effects were calculated. Results: A total of 208 patients in the 9 participating centres were enrolled. Overall, 180 patients were successfully cured from the infection, accounting for 86.5% (95% CI 81.9-91.2) and 92.3% (95% CI 88.6-96.1) eradication rates at intention-to-treat analysis and at per protocol analysis, respectively. Cure rates were similar across patients who failed one to three previous therapy attempts, but the success rate fell to 67% after 4 or more therapy failures. Compliance to therapy was good in 198 (95.2%) patients, whilst in 7 (5.3%) cases the therapy was interrupted within 5 days due to side effects. A total of 97 (46.6%) patients complained of at least one side effect; nausea, diarrhea and vomiting were the most frequently reported. Conclusions: Our study found that this bismuth-based quadruple therapy is highly effective as second-line and rescue therapy for H. pylori eradication in clinical practic
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