233 research outputs found

    STUDENTS' EVALUATIONS OF UNIVERSITY TEACHING: A STRUCTURAL EQUATION MODELING ANALYSIS

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    In this paper a Student Satisfaction survey was conducted. The used questionnaire was proposed by a very large Research Group in 2010. The collected data was elaborated by a full reflective Structural Equation Model using PLS path model estimation. The first results showed that the influence of the Organization and Infrastructure on the Student Satisfaction were not statistically significant. Therefore a more complex model was supposed, the end results showed that the influence of Organization and Infrastructure on the SS was indirect, that is the Organization and the Infrastructures exert an influence upon the SS through the Didactics

    Slow Diffeomorphisms of a Manifold with Two Dimensions Torus Action

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    The uniform norm of the differential of the n-th iteration of a diffeomorphism is called the growth sequence of the diffeomorphism. In this paper we show that there is no lower universal growth bound for volume preserving diffeomorphisms on manifolds with an effective two dimensions torus action by constructing a set of volume-preserving diffeomorphisms with arbitrarily slow growth.Comment: 12 p

    Radical antegrade modular pancreatosplenectomy: Myth or reality? A systematic review and trial sequential meta-analysis

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    Background: The superiority of radical antegrade modular pancreatosplenectomy versus standard distal pancreatectomy has never been demonstrated. Methods: A systematic review was performed to identify all comparative studies about radical antegrade modular pancreatosplenectomy versus standard distal pancreatectomy. Random-effects analysis was performed, and hazard ratios, odds ratios, and mean differences were calculated. Using trial sequential analysis, type I and II errors were evaluated by comparing the accrued sample size with the required sample size. When the required sample size is superior to the accrued sample size, type I or II errors can be hypothesized. The critical endpoint was overall survival. Secondary endpoints were disease-free survival, R0 resection rate, major morbidity and mortality rate, clinically relevant postoperative pancreatic fistula, delayed gastric emptying, postpancreatectomy hemorrhage, length of stay, and operative time. Results: The accrued sample size and required sample size were 1,172 and 176 for the primary endpoint, respectively. The overall survival was similar between the 2 groups, with a hazard ratio of 1.33 (95% confidence interval: 0.89-2.0 0). The required sample size reached, and false-negative equivalence can be excluded. Disease-free survival, R0 resection rate, major morbidity and mortality rate, clinically relevant postoperative pancreatic fistula, delayed gastric emptying, postpancreatectomy hemorrhage, and operative time are similar and reached required sample sizes, suggesting that false equivalence can be excluded. Length of stay was shorter in radical antegrade modular pancreatosplenectomy than in standard distal pancreatectomy (-3.48 days; -6.66 to -0.31 days). The accrued sample size was 826, and the required sample size was not reached. False-positive results cannot be excluded. Conclusion: Radical antegrade modular pancreatosplenectomy was not superior in guaranteeing a better overall survival and disease-free survival. The data are robust, and further retrospective comparative studies are unnecessary. (c) 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

    Alcune considerazioni sull’analisi multidimensionale dei dati nella valutazione dei servizi di day surgery

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    The evaluation of the quality on the Day Surgery service is an actual problem. The conceptual models proposed in literature allow to collected data of the different nature: ordinal, compositional, and so on. The multidimensional analysis of these data gives more problems and difficulties. Aim of this paper is to think about the mentioned problems as well as to suggest suitable multidimensional methods. Finally, the appropriateness of the inclusion the external information in a customers satisfaction framework is given

    Surgical and oncological implications of the presence of hepatic artery anatomical variations in patients undergoing pancreaticoduodenectomy: a single center experience

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    The presence of an aberrant right hepatic artery (a-RHA) could influence the oncological and postoperative outcomes after pancreaticoduodenectomy (PD). A comparative study was conducted, including patients who underwent PD with a-RHA or with normal RHA anatomy. The primary endpoints were R1 resection in all margins (pancreatic, anterior, posterior, superior mesenteric artery, and portal groove), overall survival (OS), and disease-free survival (DFS). The secondary endpoints were morbidity, mortality, biliary leak (BL), postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), post pancreatectomy hemorrhage (PPH), length of stay (LOS), and operative time (OT). The selection bias was measured using the d-value and limited using entropy balancing analysis. Patients with arterial variants were 84 (37.5%), 39 (17.4%) of whom had a-RHA from SMA. The patients with a-RHA were more frequently symptomatic (d = 0.652), often affected by PDAC (d = 0.369), and judged borderline resectable (d = 0.588). Neoadjuvant therapy was more frequently proposed for patients with a-RHA (d = 0.465). The patients with a-RHA often had the Wirsung dilated compared to those without a-RHA (d = 0.336). After bias correction, the R1 resection rate on the superior mesenteric artery (SMA) margin was higher in the a-RHA group than in patients with normal RHA anatomy (OR 2.3; 1.1-5.2; P = 0.045). OS, DFS, morbidity, mortality, biliary leak (BL), postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), post pancreatectomy hemorrhage (PPH), length of stay (LOS), and operative time (OT) were similar in unmatched and matched population. The presence of a-RHA seems to increase the risk of R1 resection in the SMA margin

    Finite-element-method (FEM) model generation of time-resolved 3D echocardiographic geometry data for mitral-valve volumetry

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    INTRODUCTION: Mitral Valve (MV) 3D structural data can be easily obtained using standard transesophageal echocardiography (TEE) devices but quantitative pre- and intraoperative volume analysis of the MV is presently not feasible in the cardiac operation room (OR). Finite element method (FEM) modelling is necessary to carry out precise and individual volume analysis and in the future will form the basis for simulation of cardiac interventions. METHOD: With the present retrospective pilot study we describe a method to transfer MV geometric data to 3D Slicer 2 software, an open-source medical visualization and analysis software package. A newly developed software program (ROIExtract) allowed selection of a region-of-interest (ROI) from the TEE data and data transformation for use in 3D Slicer. FEM models for quantitative volumetric studies were generated. RESULTS: ROI selection permitted the visualization and calculations required to create a sequence of volume rendered models of the MV allowing time-based visualization of regional deformation. Quantitation of tissue volume, especially important in myxomatous degeneration can be carried out. Rendered volumes are shown in 3D as well as in time-resolved 4D animations. CONCLUSION: The visualization of the segmented MV may significantly enhance clinical interpretation. This method provides an infrastructure for the study of image guided assessment of clinical findings and surgical planning. For complete pre- and intraoperative 3D MV FEM analysis, three input elements are necessary: 1. time-gated, reality-based structural information, 2. continuous MV pressure and 3. instantaneous tissue elastance. The present process makes the first of these elements available. Volume defect analysis is essential to fully understand functional and geometrical dysfunction of but not limited to the valve. 3D Slicer was used for semi-automatic valve border detection and volume-rendering of clinical 3D echocardiographic data. FEM based models were also calculated. METHOD: A Philips/HP Sonos 5500 ultrasound device stores volume data as time-resolved 4D volume data sets. Data sets for three subjects were used. Since 3D Slicer does not process time-resolved data sets, we employed a standard movie maker to animate the individual time-based models and visualizations. Calculation time and model size were minimized. Pressures were also easily available. We speculate that calculation of instantaneous elastance may be possible using instantaneous pressure values and tissue deformation data derived from the animated FEM

    The Italian Unitary Society of Colon-proctology (SIUCP: Società Italiana Unitaria di Colonproctologia) guidelines for the management of anal fissure

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    Introduction: The aim of these evidence-based guidelines is to present a consensus position from members of the Italian Unitary Society of Colon-Proctology (SIUCP: Società Italiana Unitaria di Colon-Proctologia) on the diagnosis and management of anal fissure, with the purpose to guide every physician in the choice of the best treatment option, according with the available literature. Methods: A panel of experts was designed and charged by the Board of the SIUCP to develop key-questions on the main topics covering the management of anal fissure and to performe an accurate search on each topic in different databanks, in order to provide evidence-based answers to the questions and to summarize them in statements. All the clinical questions were discussed by the expert panel in different rounds through the Delphi approach and, for each statement, a consensus among the experts was reached. The questions were created according to the PICO criteria, and the statements developed adopting the GRADE methodology. Conclusions: In patients with acute anal fissure the medical therapy with dietary and behavioral norms is indicated. In the chronic phase of disease, the conservative treatment with topical 0.3% nifedipine plus 1.5% lidocaine or nitrates may represent the first-line therapy, eventually associated with ointments with film-forming, anti-inflammatory and healing properties such as Propionibacterium extract gel. In case of first-line treatment failure, the surgical strategy (internal sphincterotomy or fissurectomy with flap), may be guided by the clinical findings, eventually supported by endoanal ultrasound and anal manometry

    The Italian Unitary Society of Colon-Proctology (Società Italiana Unitaria di Colonproctologia) guidelines for the management of acute and chronic hemorrhoidal disease

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    The aim of these evidence-based guidelines is to present a consensus position from members of the Italian Unitary Society of Colon-Proctology (Società Italiana Unitaria di Colon-Proctologia, SIUCP) on the diagnosis and management of hemorrhoidal disease, with the goal of guiding physicians in the choice of the best treatment option. A panel of experts was charged by the Board of the SIUCP to develop key questions on the main topics related to the management of hemorrhoidal disease and to perform an accurate and comprehensive literature search on each topic, in order to provide evidence-based answers to the questions and to summarize them in statements. All the clinical questions were discussed by the expert panel in multiple rounds through the Delphi approach and, for each statement, a consensus among the experts was reached. The questions were created according to PICO (patients, intervention, comparison, and outcomes) criteria, and the statements were developed adopting the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) methodology. In cases of grade 1 hemorrhoidal prolapse, outpatient procedures including hemorrhoidal laser procedure and sclerotherapy may be considered the preferred surgical options. For grade 2 prolapse, nonexcisional procedures including outpatient treatments, hemorrhoidal artery ligation and mucopexy, laser hemorrhoidoplasty, the Rafaelo procedure, and stapled hemorrhoidopexy may represent the first-line treatment options, whereas excisional surgery may be considered in selected cases. In cases of grades 3 and 4, stapled hemorrhoidopexy and hemorrhoidectomy may represent the most effective procedures, even if, in the expert panel opinion, stapled hemorrhoidopexy represents the gold-standard treatment for grade 3 hemorrhoidal prolapse
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