65 research outputs found

    Quasi-elastic processes of the 48Ca + 120Sn system and the 48Ca nuclear matter density

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    Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al.We present the results of a high-precision quasi-elastic excitation function measurement for the 48Ca + 120Sn system at ΞLAB = 160 at near-barrier energies in steps of 1.0 MeV. The corresponding quasi-elastic barrier distribution is derived. A large-scale coupled-channel calculation was performed to investigate the role of several reaction channels in the reaction mechanism. An excellent agreement between theory and data was obtained for the barrier distribution. The first quadrupole vibrations of the 48Ca and 120Sn, the 2n, and the 4He transfers have a strong influence on the reaction mechanism and are responsible for the good agreement achieved. The 1n transfer has a minor importance in the result when compared with the 2n transfer, which suggests that the pairing correlation might play an important role in the 2n-neutron transfer process. However, if the octupole vibration of the projectile is included in the coupling scheme, the agreement with the data gets worse. The comparison of the coupled-channel calculations with experimental data leads to the conclusion that the nuclear matter diffuseness of the 48Ca nucleus is 0.56 fm in agreement with most of the double-magic nuclei. © 2013 American Physical Society.The authors acknowledge the financial support of Fundaçùo de Amparo Ă  Pesquisa do Estado de SĂąo Paulo (FAPESPBrazil), Fundaçùo de Amparo Ă  Pesquisa do Estado do Rio de Janeiro (FAPERJ-Brazil), Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPq-Brazil), The Pronex (Brazil), and the European Community FP7—Capacities-Integrated Infrastructure Initiative—Contract No. ENSAR 262010.Peer Reviewe

    FIRST experiment: Fragmentation of Ions Relevant for Space and Therapy

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    Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon targe

    Performance of upstream interaction region detectors for the FIRST experiment at GSI

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    The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at GSI has been designed to study carbon fragmentation, measuring 12C double differential cross sections (∂2σ/ ∂ξ∂E) for different beam energies between 100 and 1000 MeV/u. The experimental setup integrates newly designed detectors in the, so called, Interaction Region around the graphite target. The Interaction Region upstream detectors are a 250 ÎŒm thick scintillator and a drift chamber optimized for a precise measurement of the ions interaction time and position on the target. In this article we review the design of the upstream detectors along with the preliminary results of the data taking performed on August 2011 with 400 MeV/u fully stripped carbon ion beam at GSI. Detectors performances will be reviewed and compared to those obtained during preliminary tests, performed with 500 MeV electrons (at the BTF facility in the INFN Frascati Laboratories) and 80 MeV/u protons and carbon ions (at the INFN LNS Laboratories in Catania)

    Precise measurement of near-barrier He 8 + Pb 208 elastic scattering: Comparison with He 6

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    et al.Dramatic differences in the elastic scattering of the neutron rich nuclei He6 and He8 are found when new high quality data for the He8+Pb208 system are compared with previously published He6+Pb208 data at the same laboratory frame incident energy. The new He8 data are of the same level of detail as for stable beams. When comparing them with those previously obtained for He6+Pb208 at the same energy, it is possible to determine from the data alone that He6 has a much longer range absorption than He8. However, both nuclei show significant absorption beyond their strong absorption radii. While it has been known for a long time that elastic scattering at energies around the barrier only determines the optical potential over a small distance in radial space, typically ±0.5 fm or so, both the He6 and the He8 imaginary potentials obtained from various optical model fits to these data are the same over a much wider range of ±1.5 fm. ©2016 American Physical SocietyThis work was supported in part by Grant No. FPA2010-22131- C02-01 (FINURA) and Grant No. FPA2013-47327-C2-1-R from the Spanish Ministry of Economy and Competitiveness, UNAM-PAPIIT IA101616 (Mexico), Grant No. N202 033637 from the Ministry of Science and Higher Education of Poland, and Contract No. EUI2009-04163 (EUROGENESIS) from the European Science Foundation.Peer Reviewe

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Abstracts of presentations on plant protection issues at the fifth international Mango Symposium Abstracts of presentations on plant protection issues at the Xth international congress of Virology: September 1-6, 1996 Dan Panorama Hotel, Tel Aviv, Israel August 11-16, 1996 Binyanei haoma, Jerusalem, Israel

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    Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children

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    We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2

    Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

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    Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

    Silicon strip detector for a novel 2D dosimetric method for radiotherapy treatment verification

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    et al.Work supported by the EU Initial Training Marie Curie Network “DIagnostic TEchniques for future particle Accelerators NETwork” (DITANET) under contract PITN-GA-2008-215080; by the Spanish Research Project FPA2009-08848; by the Consolider-Ingenio project CSD2007-0042; and by the RADIA2 project, a collaboration between Instalaciones Inabensa S.A. and University of Seville under contracts 68/83 0214/0129 (EU-Spanish), IAP-560610-2008-8 (Spanish), and 08/221 and 841190 (Andalusian).Peer reviewe

    Output factor determination for dose measurements at axial and perpendicular planes using a silicon strip detector

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    7 páginas, 11 figuras, 4 tablas.-- Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License.-- et al.In this work we present the output factor measurements of a clinical linear accelerator using a silicon strip detector coupled to a new system for complex radiation therapy treatment verification. The objective of these measurements is to validate the system we built for treatment verification. The measurements were performed at the Virgin Macarena University Hospital in Seville. Irradiations were carried out with a Siemens ONCORℱ linac used to deliver radiotherapy treatment for cancer patients. The linac was operating in 6 MV photon mode; the different sizes of the fields were defined with the collimation system provided within the accelerator head. The output factor was measured with the silicon strip detector in two different layouts using two phantoms. In the first, the active area of the detector was placed perpendicular to the beam axis. In the second, the innovation consisted of a cylindrical phantom where the detector was placed in an axial plane with respect to the beam. The measured data were compared with data given by a commercial treatment planning system. Results were shown to be in a very good agreement between the compared set of data.This work is supported by the EU Initial Training Marie Curie Network: ‘‘Diagnostics and Techniques for future particles Accelerators NETwork’’—DITANET project under Contract No. PITN-GA-2008-215080, by the Spanish Research Projects No. FPA2009-08848 and No. FPA2008-04972-C03-02, the government of Andalusia Research Project No. PO7-FQM02894, the Consolider-Ingenio Project No. CSD2007-00042 and the RADIA2 project by Instalaciones Inabensa S. A. under Contract No. 68/83 0214/0129.Peer Reviewe
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