143 research outputs found

    Radio emission from Supernova Remnants

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    The explosion of a supernova releases almost instantaneously about 10^51 ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from a SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critical discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analyzing the prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure

    Evaluation of DNA ploidy in relation with established prognostic factors in patients with locally advanced (unresectable) or metastatic pancreatic adenocarcinoma: a retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>Most patients with ductal pancreatic adenocarcinoma are diagnosed with locally advanced (unresectable) or metastatic disease. The aim of this study was to evaluate the prognostic significance of DNA ploidy in relation with established clinical and laboratory variables in such patients.</p> <p>Methods</p> <p>Two hundred and twenty six patients were studied retrospectively. Twenty two potential prognostic variables (demographics, clinical parameters, biochemical markers, treatment modality) were examined.</p> <p>Results</p> <p>Mean survival time was 38.41 weeks (95% c.i.: 33.17–43.65), median survival 27.00 weeks (95% c.i.: 23.18–30.82). On multivariate analysis, 10 factors had an independent effect on survival: performance status, local extension of tumor, distant metastases, ploidy score, anemia under epoetin therapy, weight loss, pain, steatorrhoea, CEA, and palliative surgery and chemotherapy. Patients managed with palliative surgery and chemotherapy had 6.7 times lower probability of death in comparison with patients without any treatment. Patients with ploidy score > 3.6 had 5.0 times higher probability of death in comparison with patients with ploidy score < 2.2 and these with ploidy score 2.2–3.6 had 6.3 times higher probability of death in comparison with patients with ploidy score < 2.2.</p> <p>Conclusion</p> <p>According to the significance of the examined factor, survival was improved mainly by the combination of surgery and chemotherapy, and the presence of low DNA ploidy score.</p

    GM-CSF drives dysregulated hematopoietic stem cell activity and pathogenic extramedullary myelopoiesis in experimental spondyloarthritis

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    Dysregulated hematopoiesis occurs in several chronic inflammatory diseases, but it remains unclear how hematopoietic stem cells (HSCs) in the bone marrow (BM) sense peripheral inflammation and contribute to tissue damage in arthritis. Here, we show the HSC gene expression program is biased toward myelopoiesis and differentiation skewed toward granulocyte-monocyte progenitors (GMP) during joint and intestinal inflammation in experimental spondyloarthritis (SpA). GM-CSF-receptor is increased on HSCs and multipotent progenitors, favoring a striking increase in myelopoiesis at the earliest hematopoietic stages. GMP accumulate in the BM in SpA and, unexpectedly, at extramedullary sites: in the inflamed joints and spleen. Furthermore, we show that GM-CSF promotes extramedullary myelopoiesis, tissue-toxic neutrophil accumulation in target organs, and GM-CSF prophylactic or therapeutic blockade substantially decreases SpA severity. Surprisingly, besides CD4+ T cells and innate lymphoid cells, mast cells are a source of GM-CSF in this model, and its pathogenic production is promoted by the alarmin IL-33

    Different strategies for mechanical VENTilation during CardioPulmonary Bypass (CPBVENT 2014): Study protocol for a randomized controlled trial

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    Background: There is no consensus on which lung-protective strategies should be used in cardiac surgery patients. Sparse and small randomized clinical and animal trials suggest that maintaining mechanical ventilation during cardiopulmonary bypass is protective on the lungs. Unfortunately, such evidence is weak as it comes from surrogate and minor clinical endpoints mainly limited to elective coronary surgery. According to the available data in the academic literature, an unquestionable standardized strategy of lung protection during cardiopulmonary bypass cannot be recommended. The purpose of the CPBVENT study is to investigate the effectiveness of different strategies of mechanical ventilation during cardiopulmonary bypass on postoperative pulmonary function and complications. Methods/design: The CPBVENT study is a single-blind, multicenter, randomized controlled trial. We are going to enroll 870 patients undergoing elective cardiac surgery with planned use of cardiopulmonary bypass. Patients will be randomized into three groups: (1) no mechanical ventilation during cardiopulmonary bypass, (2) continuous positive airway pressure of 5 cmH2O during cardiopulmonary bypass, (3) respiratory rate of 5 acts/min with a tidal volume of 2-3 ml/Kg of ideal body weight and positive end-expiratory pressure of 3-5 cmH2O during cardiopulmonary bypass. The primary endpoint will be the incidence of a PaO2/FiO2ratio <200 until the time of discharge from the intensive care unit. The secondary endpoints will be the incidence of postoperative pulmonary complications and 30-day mortality. Patients will be followed-up for 12 months after the date of randomization. Discussion: The CPBVENT trial will establish whether, and how, different ventilator strategies during cardiopulmonary bypass will have an impact on postoperative pulmonary complications and outcomes of patients undergoing cardiac surgery. Trial registration: ClinicalTrials.gov, ID: NCT02090205. Registered on 8 March 2014

    Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

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