2,914 research outputs found

    Measurements and tests on FBK silicon sensors with an optimized electronic design for a CTA camera

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    In October 2013, the Italian Ministry approved the funding of a Research & Development (R&D) study, within the "Progetto Premiale TElescopi CHErenkov made in Italy (TECHE)", devoted to the development of a demonstrator for a camera for the Cherenkov Telescope Array (CTA) consortium. The demonstrator consists of a sensor plane based on the Silicon Photomultiplier (SiPM) technology and on an electronics designed for signal sampling. Preliminary tests on a matrix of sensors produced by the Fondazione Bruno Kessler (FBK-Trento, Italy) and on electronic prototypes produced by SITAEL S.p.A. will be presented. In particular, we used different designs of the electronics in order to optimize the output signals in terms of tail cancellation. This is crucial for applications where a high background is expected, as for the CTA experiment.Comment: 5 pages, 6 figures; Proceedings of the 10th Workshop on Science with the New Generation of High-Energy Gamma-ray experiments (SciNeGHE) - PoS(Scineghe2014)00

    Fine-needle aspiration cytology in children with superficial lymphadenopathy.

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    Introduction: In pediatric population Fine-Needle Aspiration Citology (FNAC) is slowly gaining acceptance in clinical management of Superficial Lymphadenopathy (SL). Our experience adds some data about the usefulness of this technique in diagnosing the cause of a SL and therefore guiding further treatment. Patients and Methods: 238 FNAC were performed in 217 patients with SL, observed at our Institution from 2002 to 2006. The neck was the most frequent localization. The results were available within few hours. In cases of granulomatous findings, the samples were processed for microbiological and PCR test, in order to identify Mycobacteria. Results: 174 were reactive lesions, 38 granulomatous lymphadenopathies, 24 malignant lesions, 2 specimens inadequate for diagnosis. Among the 174 reactive SL, 22 required an incisional biopsy after 1 month follow-up. Among the granulomatous lymphadenopathies, 13 children with Cat-Scratch Disease recovered, 25 with Mycobacteria infection underwent surgical excision. For 24 malignant lesions, the diagnosis was confirmed by further biopsy. Two false negative and no false positive were detected (sensitivity 92%, specificity 100%). No complications were encountered. Conclusions: In our experience FNAC, performed by experienced cytopathologist, has revealed to be a fast, safe, non invasive and inexpensive method to achieve diagnosis in persistent SL. The use of FNAC gave us the possibility to select patients for further investigation and/or surgical treatment. Incisional biopsy remains necessary to confirm the diagnosis in case of malignancy or doubtful lesions

    Comparative Effectiveness of Gemcitabine plus Nab-Paclitaxel and FOLFIRINOX in the First-Line Setting of Metastatic Pancreatic Cancer: A Systematic Review and Meta-Analysis

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    Gemcitabine and nab-paclitaxel (GEM-NAB) and the combination of 5-fluorouracil, oxaliplatin, and irinotecan (FOLFIRINOX) are valid first-line options for advanced or metastatic pancreatic cancer (mPC). However, no randomized trials comparing the two schemes have been performed. This meta-analysis aims to compare GEM-NAB and FOLFIRINOX in terms of safety and effectiveness, taking into account data from real-life studies on mPC. We systematically searched PubMed, EMBASE and Cochrane library up to November 2018 to identify retrospective or cohort studies on mPC comparing GEM-NAB and FOLFIRINOX. We included 16 retrospective studies, including 3813 patients (2123 treated with GEM-NAB and 1690 treated with FOLFIRINOX). Despite a median weighted overall survival (OS) difference in favor of FOLFIRINOX (mean difference: 1.15, 95% confidence interval CI 0.08\u207b2.22, p = 0.03), in whole population OS was similar (hazard ratio (HR = 0.99, 95% CI 0.84\u207b1.16; p = 0.9). PFS was also not different between the two arms (HR = 0.88, 95% CI 0.71\u207b1.1; p = 0.26). The overall response rate was similar (25 vs. 24% with GEM-NAB and FOLFIRINOX). Among grade 3\u207b4 toxicities, neutropenia, febrile neutropenia, and nausea were lower with GEM-NAB, while neurotoxicity and anemia were lower with FOLFIRINOX. In conclusion, despite a numerically longer median OS with FOLFIRINOX as compared to GEM-NAB, the overall risk of death and progression were similar. Their toxicity was different with less nausea, neutropenia, and febrile neutropenia with GEM-NAB, as compared to less neurotoxicity and anemia with FOLFIRINOX. Therefore, analysis of non-randomized "real world" studies to date has not provided evidence of a major benefit of one regimen over the other

    Glassy Transition in the Vortex Lattice of Ba(Fe0.93Rh0.07)2As2 superconductor, probed by NMR and ac-susceptibility

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    By using Nuclear Magnetic Resonance and ac-susceptibility, the characteristic correlation times for the vortex dynamics, in an iron-based superconductor, have been derived. Upon cooling, the vortex dynamics displays a crossover consistent with a vortex glass transition. The correlation times, in the fast motions regime, merge onto a universal curve which is fit by the Vogel-Fulcher law, rather than by an Arrhenius law. Moreover, the pinning barrier shows a weak dependence on the magnetic field which can be heuristically justified within a fragile glass scenario. In addition, the glass freezing temperatures obtained by the two techniques merge onto the de Almeida-Thouless line. Finally the phase diagram for the mixed phase has been derived.Comment: 6 pages, 9 figure

    Percutaneous Trans-Thoracic Procedures in Children With Tumors of Thoracic Wall, Mediastinum and Lung. The Experience of a Single Institution

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    Background While percutaneous trans-thoracic procedures (PTTP) are commonly performed in adults with tumors of thoracic wall, mediastinum and lung, the experience is limited in children, in whom however less invasive methods should be the choice for the diagnosis or the identification of small pulmonary nodules that need to be removed, sparing lung tissue. The results of the PTTP performed by the interventional radiologists in our Pediatric Surgery Department are analyzed. Methods CT-guided biopsies, utilizing a 64-slice CTscanner, with low-radiation dose, were performed applying the coaxial technique with 16-18G needles with a single tissue path. For localization of lung nodules before surgery, two 20G-hook wires were positioned beyond the nodule. CT images after each manipulation of the needles were obtained. US-guided biopsies were performed either with or without coaxial technique through a needle bracket. Younger patients required sedation. All patients underwent a chest radiogram two hours after the procedure and remained under observation for 24 hours. Results From January 2015 to March 2019, 23 procedures were performed in 22 patients (Age:16M- 19Y): 6 patients underwent CT-guided biopsy (4 lung nodules, 2 mediastinal mass); 3 underwent 4 CT-guided hook-wire localization of pulmonary nodules, just before surgery; 13 underwent US-guided biopsy (posterior mediastinum 2; anterior mediastinum 5, thoracic/intrathoracic mass 5). Adequate core biopsies were obtained in all patients, except three, who underwent thoracoscopy/thoracotomy. The hook-wires were successfully positioned in all cases, as confirmed by histology. After the procedure, two patients presented perilesional hemorrhage and one pneumothorax, but they did not required treatment. Conclusion PTTP were successful in most patients, without significant complications. These techniques should be encouraged to avoid diagnostic aggressive surgical approaches in children with cancer. For all cases a multidisciplinary team is essential to discuss the indications and planning the procedures

    Design of a SiPM-based cluster for the Large Size Telescope camera of CTA

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    A Silicon Photomultiplier (SiPM)-based photodetector is being built to demonstrate its feasibility for an alternative silicon-based camera design for the Large Size Telescope (LST) of the Cherenkov Telescope Array. It has been designed to match the size of the standard Photomultiplier Tube (PMT) cluster unit and to be compatible with mechanics, electronics and focal plane optics of the first LST camera. Here, we describe the overall SiPM cluster design along with the main differences with respect to the currently used PMT cluster unit. The fast electronics of the SiPM pixel and its layout are also presented. In order to derive the best working condition for the final unit, we measured the SiPM performances in terms of gain, photo-detection efficiency and cross-talk. One pixel, a unit of 14 SiPMs, has been built. We will discuss also some preliminary results regarding this device and we will highlight the future steps of this project.Comment: submitted to NIM

    Stalking influenza by vaccination with pre-fusion headless HA mini-stem.

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    Inaccuracies in prediction of circulating viral strain genotypes and the possibility of novel reassortants causing a pandemic outbreak necessitate the development of an anti-influenza vaccine with increased breadth of protection and potential for rapid production and deployment. The hemagglutinin (HA) stem is a promising target for universal influenza vaccine as stem-specific antibodies have the potential to be broadly cross-reactive towards different HA subtypes. Here, we report the design of a bacterially expressed polypeptide that mimics a H5 HA stem by protein minimization to focus the antibody response towards the HA stem. The HA mini-stem folds as a trimer mimicking the HA prefusion conformation. It is resistant to thermal/chemical stress, and it binds to conformation-specific, HA stem-directed broadly neutralizing antibodies with high affinity. Mice vaccinated with the group 1 HA mini-stems are protected from morbidity and mortality against lethal challenge by both group 1 (H5 and H1) and group 2 (H3) influenza viruses, the first report of cross-group protection. Passive transfer of immune serum demonstrates the protection is mediated by stem-specific antibodies. Furthermore, antibodies indudced by these HA stems have broad HA reactivity, yet they do not have antibody-dependent enhancement activity

    Factors precipitating the risk of aspiration in hospitalized patients: findings from a multicentre critical incident technique study

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    Objective: To elucidate factors, other than those clinical, precipitating the risk of aspiration in hospitalized patients. Design: The Critical Incident Technique was adopted for this study in 2015. Setting: Three departments located in two academic hospitals in the northeast of Italy, equipped with 800 and 1500 beds, respectively. Participants: A purposeful sample of 12 registered nurses (RN), all of whom (i) had reported one or more episodes of aspiration during the longitudinal survey, (ii) had worked 653 years in the department, and (iii) were willing to participate, were included. Main Outcome Measure(s): Antecedent factors involved in episodes of aspiration as experienced by RNs were collected through an open-ended interview, and qualitatively analysed. Results: In addition to clinical factors, other factors interacting with each other may precipitate the risk of aspiration episodes during hospitalization: at the nursing care level (misclassifying patients, transferring tasks to other healthcare professionals and standardizing processes to remove potential threats); at the family level (misclassifying patients, dealing with the cultural relevance of eating) and at the environmental level (positioning the patient, managing time pressures, distracting patient while eating, dealing with food consistency and irritating oral medication). Conclusions: At the hospital level, an adequate nursing workforce and models of care delivery, as well as time for initial and continuing patient and family assessment are required. At the unit level, patient-centred models of care aimed at reducing care standardization are also recommended; in addition, nursing, family and environmental factors should be recorded in the incident reports documenting episodes of aspiratio
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