5,929 research outputs found

    Probing cosmological parameters with GRBs

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    In light of the recent finding of the narrow clustering of the geometrically-corrected gamma-ray energies emitted by Gamma Ray Bursts (GRBs), we investigate the possibility to use these sources as standard candles to probe cosmological parameters such as the matter density Omega_m and the cosmological constant energy density Omega_Lambda. By simulating different samples of gamma-ray bursts, based on recent observational results, we find that Omega_m (with the prior Omega_m + Omega_Lambda = 1) can be determined with accuracy ~7% with data from 300 GRBs, provided a local calibration of the standard candles be achieved.Comment: 4 pages, 2 figures, to appear in the Proceedings of the Conference "30 Years of GRB Discovery", Santa Fe, New Mexico, USA, September 8-12, 200

    Nellix endovascular aortic sealing endoprosthesis late explantation for concomitant type I endoleak and stent frames proximal caudal migration

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    Endovascular aneurysm sealing (EVAS) using the Nellix™ System was introduced in clinical practice with the aim of reducing the incidence of complications such as migration, endoleaks, and reinterventions after conventional endovascular aneurysm repair (EVAR). Although, initial efficacy data on this device have been encouraging, EVAS has also demonstrated to undergo adverse events. Herein, we report a case of Nellix graft explant due to endobags shrinkage after air bubble reabsorption leading to proximal type I A endoleak and stent migration. The focus of this article is on the importance of a more assiduous surveillance of this new device, in particular in those cases with air into the endobags immediately after the procedure; this surveillance should be aimed to timely identify complications which can otherwise lead to consequences that require open conversion

    Lidar in Space Technology Experiment correlative measurements by lidar in Potenza, southern Italy.

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    An intensive lidar measurement campaign was carried out in Potenza (40°36′N-15°44′E, 820 m above sea level (asl)) in conjunction with the Lidar in Space Technology Experiment (LITE) mission and primarily aimed at the validation of LITE stratospheric aerosol measurements. Potenza lidar measurements in coincidence with all five nighttime overpasses near southern Italy (September 11, 12, 17, and 18, 1994) are compared with simultaneous LITE data. Potenza lidar data appear to be highly correlated with LITE data both at 355 and 532 nm. Potenza lidar versus LITE measurements of the aerosol-scattering ratio show a correlation coefficient of 0.72–0.81 at 355 nm and 0.88–0.93 at 532 nm, with an average calibration coefficient of 0.92 ± 0.19 at 355 nm and 1.02 ± 0.07 at 532 nm. Comparisons are also made in terms of the average Angstrom coefficient, whose values are consistent with submicrometer aerosol particles. Finally, Potenza lidar measurements of the aerosol layer base and top heights, the peak aerosol-scattering ratio and peak height, as well as of the aerosol scattering ratio at the cloud base appear to be consistent with measurements performed by other ground lidar stations in Europe during the LITE campaign as well as with the LITE data

    In silico analysis of TTR gene (coding and non-coding regions, and interactive network) and its implications in transthyretin-related amyloidosis.

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    Introduction: Transthyretin (TTR)-related amyloidosis is a life-threatening disease. Currently, several questions about the pathogenic mechanisms of TTR-related amyloidosis remain unanswered. Methods: We have investigated various TTR-related issues using different in silico approaches. Results: Using an amino acid similarity-based analysis, we have indicated the most relevant TTR secondary structures in determining mutation impact. Our amyloidogenic propensity analysis of TTR missense substitutions has highlighted a similar pattern for wild-type and mutated TTR amino b acid sequences. However, some mutations present differences with respect to the general distribution. We have identified non-coding variants in cis-regulatory elements of the TTR gene, and our analysis on V122I-related haplotypes has indicated differences in non-coding regulatory variants, suggesting differences among V122I carriers. The analysis of methylation status indicated CpG sites that may affect TTR expression. Finally, our interactive network analysis revealed functional partners of TTR that may play a modifier role in the pathogenesis of TTR-related amyloidosis. Discussion and conclusion: Our data provided new insights into the pathogenesis of TTR-related amyloidosis that, if they were to be confirmed through experimental investigations, could significantly improve our understanding of the disease

    Surgical management of rhinosinusitis in onco-hematological patients

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    ObjectivesIn onco-hematological diseases, the incidence of paranasal sinuses infection dramatically increase and requires a combination of medical and surgical therapy. Balloon dilatation surgery (DS) is a minimally invasive, tissue preserving procedure. The study evaluates the results of DS for rhinosinusitis in immunocompromised patients.MethodsA retrospective chart review was conducted in 110 hematologic patients with rhinosinusitis. Twenty-five patients were treated with DS technique and 85 patients with endoscopic sinus surgery (ESS). We considered the type of anesthesia and the extent of intra- and postoperative bleeding. Patients underwent Sino-Nasal Outcome Test (SNOT-20) to evaluate changes in subjective symptoms and global patient assessment (GPA) questionnaire to value patient satisfaction.ResultsLocal anesthesia was employed in 8 cases of DS and in 15 of ESS. In 50 ESS patients, an anterior nasal packing was placed and in 12 cases a repacking was necessary. In the DS group, nasal packing was required in 8 cases and in 2 cases a repacking was placed (P=0.019 and P=0.422, respectively). The SNOT-20 change score showed significant improvement of health status in both groups. However the DS group showed a major improvement in 3 voices: need to blow nose, runny nose, and facial pain/pressure. The 3-month follow-up GPA questionnaire showed an higher satisfaction of DS group.ConclusionBalloon DS represents a potentially low aggressive treatment and appears to be relatively safe and effective in onco-hematologic patients. All these remarks may lead the surgeon to consider a larger number of candidates for surgical procedure

    A general estimator of the primary cosmic ray energy with the ARGO-YBJ experiment

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    The determination of the primary cosmic ray all-particle spectrum with ground-based air shower experiments usually depends on the assumed elemental composition and hadronic interaction model. Here we show that an energy estimator independent of the primary mass composition can be defined by means of shower parameters measured in the core region, as carried out in the ARGO-YBJ experiment. The energy resolution is <10% above 100 TeV and gets better with energy increasing. Being insensitive to the number of muons, this energy determination has only a weak dependence on the hadronic interaction model. The features of this energy estimator have been validated by extensive MC simulations and used in the analysis of the ARGO-YBJ data

    Atmospheric Thermodynamic Profiling through the Use of a Micro-Pulse Raman Lidar System: Introducing the Compact Raman Lidar MARCO

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    It was for a long time believed that lidar systems based on the use of high-repetition micro-pulse lasers could be effectively used to only stimulate atmospheric elastic backscatter echoes, and thus were only exploited in elastic backscatter lidar systems. Their application to stimulate rotational and roto-vibrational Raman echoes, and consequently, their exploitation in atmospheric thermodynamic profiling, was considered not feasible based on the technical specifications possessed by these laser sources until a few years ago. However, recent technological advances in the design and development of micro-pulse lasers, presently achieving high UV average powers (1–5 W) and small divergences (0.3–0.5 mrad), in combination with the use of large aperture telescopes (0.3–0.4 m diameter primary mirrors), allow one to presently develop micro-pulse laser-based Raman lidars capable of measuring the vertical profiles of atmospheric thermodynamic parameters, namely water vapor and temperature, both in the daytime and night-time. This paper is aimed at demonstrating the feasibility of these measurements and at illustrating and discussing the high achievable performance level, with a specific focus on water vapor profile measurements. The technical solutions identified in the design of the lidar system and their technological implementation within the experimental setup of the lidar prototype are also carefully illustrated and discussed

    An incidental diagnosis of SARS-CoV-2 pneumonia with magnetic resonance imaging

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    The Coronavirus disease 2019 (COVID-19) is caused by the human severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. The most common clinical findings related to COVID-19 are fever and cough, with the proportion of patients developing interstitial pneumonia. Other symptoms include dyspnea, expectoration, headache, anosmia, ageusia, myalgia and malaise. To date, the diagnostic criteria for COVID-19 include nasopharyngeal and oropharyngeal swabs. Computed tomography (CT) scans of the thorax showing signs of interstitial pneumonia are important in the management of respiratory disease and in the evaluation of lung involvement. hi the literature, there are few cases of COVID-19 pneumonia diagnosis made using magnetic resonance imaging (MRI). In our report, we describe a case of accidental detection of findings related to interstitial pneumonia in a patient who underwent abdominal MRI for other clinical reasons. A 71-year-old woman was referred to our department for an MRI scan of the abdomen as her oncological follow-up. She was asymptomatic at the time of the examination and had passed the triage carried out on all the patients prior to diagnostic tests during the COVID-19 pandemic. The images acquired in the upper abdomen showed the presence of areas of altered signal intensity involving asymmetrically both pulmonary lower lobes, with a patchy appearance and a preferential peripheral subpleural distribution. We considered these features as highly suspicious for COVID-19 pneumonia. The nasopharyngeal swab later confirmed the diagnosis of SARS-CoV-2 infection. There are limited reports about MRI features of COVID-19 pneumonia, considering that high-resolution chest CT is the imaging technique of choice to diagnose pneumonia. Nevertheless, this clinical case confirmed that it is possible to detect MRI signs suggestive of COVID-19 pneumonia. The imaging features described could help in the evaluation of the lung parenchyma to assess the presence of signs suggestive of COVID-19 pneumonia, especially in asymptomatic patients during the pandemic phase of the disease

    Characterization of the planetary boundary layer height and structure by Raman lidar: comparison of different approaches

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    Abstract. The planetary boundary layer (PBL) includes the portion of the atmosphere which is directly influenced by the presence of the earth's surface. Aerosol particles trapped within the PBL can be used as tracers to study the boundary-layer vertical structure and time variability. As a result of this, elastic backscatter signals collected by lidar systems can be used to determine the height and the internal structure of the PBL. The present analysis considers three different methods to estimate the PBL height. The first method is based on the determination of the first-order derivative of the logarithm of the range-corrected elastic lidar signals. Estimates of the PBL height for specific case studies obtained through this approach are compared with simultaneous estimates from the potential temperature profiles measured by radiosondes launched simultaneously to lidar operation. Additional estimates of the boundary layer height are based on the determination of the first-order derivative of the range-corrected rotational Raman lidar signals. This latter approach results to be successfully applicable also in the afternoon–evening decaying phase of the PBL, when the effectiveness of the approach based on the elastic lidar signals may be compromised or altered by the presence of the residual layer. Results from these different approaches are compared and discussed in the paper, with a specific focus on selected case studies collected by the University of Basilicata Raman lidar system BASIL during the Convective and Orographically-induced Precipitation Study (COPS)
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