57 research outputs found

    Impact of a dry granular flow against a rigid wall: MPM simulations with a new constitutive approach

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    The dynamic interaction between granular flowing masses and obstacles is a very complex phenomenon involving large displacements and high strain rates. To simulate the event in a continuum-based framework both advanced numerical tools and constitutive relationships are required. In this work, the impact of a dry granular mass against a rigid wall is numerically simulated using the open-source Material Point Method code ANURA3D, while the constitutive model proposed by Marveggio et al., 2021 is adopted for the granular mass. The model accounts for rate and grain packing dependence, which have been shown to be crucial to reproduce the propagation of compression and rarefaction waves inside the mass. The model is capable of reproducing “solidification” and “liquefaction” phenomena observed in the DEM impact tests results already available in the literature

    Characterisation of the immune-related transcriptome in resected biliary tract cancers

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    Although biliary tract cancers (BTCs) are known to have an inflammatory component, a detailed characterisation of immune-related transcripts has never been performed. In these studies, nCounter PanCancer Immune Profiling Panel was used to assess the expression of 770 immune-related transcripts in the tumour tissues (TTs) and matched adjacent tissues (ATs) of resected BTCs. Cox regression analysis and Kaplan-Meier methods were used to correlate findings with relapse-free survival (RFS). The first analysis in the TT and AT of an exploratory set (n = 22) showed deregulation of 39 transcripts associated with T-cell activation. Risk of recurrence was associated with a greater number of genes deregulated in AT in comparison to TT. Analysis in the whole set (n = 53) showed a correlation between AT cytotoxic T-lymphocyte antigen-4 (CTLA4) expression and RFS, which maintained statistical significance at multivariate analysis. CTLA4 expression correlated with forkhead box P3 (FOXP3) expression, suggesting enrichment in T regulatory cells. CTLA4 is known to act by binding to the cluster of differentiation 80 (CD80). No association was seen between AT CD80 expression and RFS. However, CD80 expression differentiated prognosis in patients who received adjuvant chemotherapy. We showed that the immunomodulatory transcriptome is deregulated in resected BTCs. Our study includes a small number of patients and does not enable to draw definitive conclusions; however, it provides useful insights into potential transcripts that may deserve further investigation in larger cohorts of patients. TRANSCRIPT PROFILING: Nanostring data have been submitted to GEO repository: GSE90698 and GSE906

    Fibrosis progression in paired liver biopsies from HIV/HCV co-infected patients

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    BACKGROUND: Chronic hepatitis C is more aggressive during HIV infection. Available data about risk factors of liver fibrosis in HIV/HCV co-infected patients derive from studies based on a single liver biopsy. OBJECTIVES: To evaluate the risk factors of liver fibrosis progression (LFP) and to investigate the role of antiretroviral therapy (ARV) in HIV/HCV patients who underwent paired liver biopsy. PATIENTS AND METHODS: We retrospectively studied 58 patients followed at two Infectious Diseases Departments in Northern Italy during the period 1988-2005. All specimens were double-blinded and centrally examined by two pathologists. LFP was defined when an increase of at least one stage occurred in the second biopsy, according to the Ishak-Knodell classification. RESULTS: In a univariate analysis, serum levels of alanine aminotransferase (ALT) > 150 IU/L at the first biopsy (P = 0.02), and a > 20% decrease in CD4+ cell count between the two biopsies (P = 0.007), were significantly associated with LFP. In multivariate analysis, a > 20% decrease in CD4+ cell count remained independently associated to LFP (Odds Ratio, 3.99; 95% confidence interval, 1.25-12.76; P < 0.02). Analysis of life survival curves confirmed the correlation between CD4+ cell count and LFP. CONCLUSIONS: Our findings highlight that in HIV/HCV coinfected patients, an effective antiretroviral therapy that assures a good immune-virological profile contributes to reducing the risk of LF

    Electromagnetic modelling of the SKA-LOW AAVS2 prototype

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    The computational electromagnetic modelling of a large radio telescope prototype array for the Square Kilometer Array is described. The numerical models, using the Method of Moments, are characterised by a very large number of unknowns, requiring the use of fast solution methods and high performance computing platforms. Good agreement has been obtained between results obtained on two different commercial codes. Results for both embedded element patterns and the station beam are shown. The use of the computed embedded element patterns for array calibration is briefly addressed

    Management of Asymptomatic Sporadic Nonfunctioning Pancreatic Neuroendocrine Neoplasms (ASPEN) <= 2 cm: Study Protocol for a Prospective Observational Study

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    Introduction: The optimal treatment for small, asymptomatic, nonfunctioning pancreatic neuroendocrine neoplasms (NF-PanNEN) is still controversial. European Neuroendocrine Tumor Society (ENETS) guidelines recommend a watchful strategy for asymptomatic NF-PanNEN <2 cm of diameter. Several retrospective series demonstrated that a non-operative management is safe and feasible, but no prospective studies are available. Aim of the ASPEN study is to evaluate the optimal management of asymptomatic NF-PanNEN ≤2 cm comparing active surveillance and surgery. Methods: ASPEN is a prospective international observational multicentric cohort study supported by ENETS. The study is registered in ClinicalTrials.gov with the identification code NCT03084770. Based on the incidence of NF-PanNEN the number of expected patients to be enrolled in the ASPEN study is 1,000 during the study period (2017–2022). Primary endpoint is disease/progression-free survival, defined as the time from study enrolment to the first evidence of progression (active surveillance group) or recurrence of disease (surgery group) or death from disease. Inclusion criteria are: age >18 years, the presence of asymptomatic sporadic NF-PanNEN ≤2 cm proven by a positive fine-needle aspiration (FNA) or by the presence of a measurable nodule on high-quality imaging techniques that is positive at 68Gallium DOTATOC-PET scan. Conclusion: The ASPEN study is designed to investigate if an active surveillance of asymptomatic NF-PanNEN ≤2 cm is safe as compared to surgical approach

    The Brescia Internationally Validated European Guidelines on Minimally Invasive Pancreatic Surgery (EGUMIPS)

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    Objective: To develop and update evidence-based and consensus-based guidelines on laparoscopic and robotic pancreatic surgery. Summary Background Data: Minimally invasive pancreatic surgery (MIPS), including laparoscopic and robotic surgery, is complex and technically demanding. Minimizing the risk for patients requires stringent, evidence-based guidelines. Since the International Miami Guidelines on MIPS in 2019, new developments and key publications have been reported, necessitating an update. Methods: Evidence-based guidelines on 22 topics in 8 domains were proposed: terminology, indications, patients, procedures, surgical techniques and instrumentation, assessment tools, implementation and training, and artificial intelligence. The Brescia Internationally Validated European Guidelines on Minimally Invasive Pancreatic Surgery (EGUMIPS, September 2022) used the Scottish Intercollegiate Guidelines Network (SIGN) methodology to assess the evidence and develop guideline recommendations, the Delphi method to establish consensus on the recommendations among the Expert Committee, and the AGREE II-GRS tool for guideline quality assessment and external validation by a Validation Committee. Results: Overall, 27 European experts, 6 international experts, 22 international Validation Committee members, 11 Jury Committee members, 18 Research Committee members, and 121 registered attendees of the 2-day meeting were involved in the development and validation of the guidelines. In total, 98 recommendations were developed, including 33 on laparoscopic, 34 on robotic, and 31 on general MIPS, covering 22 topics in 8 domains. Out of 98 recommendations, 97 reached at least 80% consensus among the experts and congress attendees, and all recommendations were externally validated by the Validation Committee. Conclusions: The EGUMIPS evidence-based guidelines on laparoscopic and robotic MIPS can be applied in current clinical practice to provide guidance to patients, surgeons, policy-makers, and medical societies.</p

    T-REX OU4 HIRES: the high resolution spectrograph for the E-ELT

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    The goal of this unit was to consolidate the project for the construction of the high resolution spectrometer of the E-ELT (HIRES). The task included the development of scientific cases and tools to predict the instrumental performances. From the technical point of view it included several R&D activities in collaboration with highly specialized Italian companies; it culminated with the detailed design of a highly modular instrument based on well established technologies. From the management point of view it lead to the consolidation of a large international consortium that spans over 12 countries and includes most of the European and ESO-related institutes interested in high resolution spectroscopy. This consortium is led by INAF; its formal creation is awaiting the official call by ESO for the phase-A study for the HIRES instrument of the E-ELT
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