866 research outputs found

    Nuclear level densities and gamma-ray strength functions in 44,45Sc

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    The scandium isotopes 44,45Sc have been studied with the 45Sc(3He,alpha gamma)44Sc and 45Sc(3He,3He' gamma)45Sc reactions, respectively. The nuclear level densities and gamma-ray strength functions have been extracted using the Oslo method. The experimental level densities are compared to calculated level densities obtained from a microscopic model based on BCS quasiparticles within the Nilsson level scheme. This model also gives information about the parity distribution and the number of broken Cooper pairs as a function of excitation energy. The experimental gamma-ray strength functions are compared to theoretical models of the E1, M1, and E2 strength, and to data from (gamma,n) and (gamma,p) experiments. The strength functions show an enhancement at low gamma energies that cannot be explained by the present, standard models.Comment: 21 pages, 13 figures. Published versio

    Microcanonical entropies and radiative strength functions of 50,51^{50,51}V

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    The level densities and radiative strength functions (RSFs) of 50,51^{50,51}V have been extracted using the (3^3He,αγ\alpha \gamma) and (3^3He,3^3He′γ^{\prime} \gamma) reactions, respectively. From the level densities, microcanonical entropies are deduced. The high γ\gamma-energy part of the RSF is described by the giant electric dipole resonance. A significant enhancement over the predicted strength in the region of Eγ≲3E_{\gamma} \lesssim 3 MeV is seen, which at present has no theoretical explanation.Comment: 16 pages including 9 figure

    Observation of Thermodynamical Properties in the 162^{162}Dy, 166^{166}Er and 172^{172}Yb Nuclei

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    The density of accessible levels in the (3^3He,αγ\alpha \gamma) reaction has been extracted for the 162^{162}Dy, 166^{166}Er and 172^{172}Yb nuclei. The nuclear temperature is measured as a function of excitation energy in the region of 0 -- 6 MeV. The temperature curves reveal structures indicating new degrees of freedom. The heat capacity of the nuclear system is discussed within the framework of a canonical ensemble.Comment: 12 pages, 4 figures include

    Critical temperature for quenching of pair correlations

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    The level density at low spin in the 161,162-Dy and 171,172-Yb nuclei has been extracted from primary gamma rays. The nuclear heat capacity is deduced within the framework of the canonical ensemble. The heat capacity exhibits an S-formed shape as a function of temperature, which is interpreted as a fingerprint of the phase transition from a strongly correlated to an uncorrelated phase. The critical temperature for the quenching of pair correlations is found at Tc=0.50(4) MeV.Comment: 8 pages including 4 figures, different method to extract Tc, different figures, text partly rewritte

    a pilot study, 2013

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    Introduction After recognition of European outbreaks of Clostridium difficile infections (CDIs) associated with the emergence of PCR ribotype 027/NAP1 in 2005, CDI surveillance at country level was encouraged by the European Centre for Disease Prevention and Control (ECDC) [1]. In 2008, an ECDC-supported European CDI survey (ECDIS) identified large intercountry variations in incidence rates and distribution of prevalent PCR ribotypes, with the outbreak-related PCR ribotype 027 being detected in 5% (range: 0–26) of the characterised isolates [2]. The surveillance period was limited to one month and the representation of European hospitals was incomplete; however, this has been the only European (comprising European Union (EU)/European Economic Area (EEA) and EU candidate countries) CDI surveillance study. The authors highlighted the need for national and European surveillance to control CDI. Yet, European countries were found to have limited capacity for diagnostic testing, particularly in terms of standard use of optimal methods and absence of surveillance protocols and a fully validated, standardised and exchangeable typing system for surveillance and/or outbreak investigation. As of 2011, 14 European countries had implemented national CDI surveillance, with various methodologies [3]. National surveillance systems have since reported a decrease in CDI incidence rate and/or prevalence of PCR ribotype 027 in some European countries [4-8]. However, CDI generally remains poorly controlled in Europe [9], and PCR ribotype 027 continues to spread in eastern Europe [10-12] and globally [13]. In 2010, ECDC launched a new project, the European C. difficile Infection Surveillance Network (ECDIS-Net), to enhance surveillance of CDI and laboratory capacity to test for CDI in Europe. The goal of ECDIS- Net was to establish a standardised CDI surveillance protocol suitable for application all over Europe in order to: (i) estimate the incidence rate and total infection rate of CDI (including recurrent CDI cases) in European acute care hospitals; (ii) provide participating hospitals with a standardised tool to measure and compare their own incidence rates with those observed in other participating hospitals; (iii) assess adverse outcomes of CDI such as complications and death; and (iv) describe the epidemiology of CDI concerning antibiotic susceptibility, PCR ribotypes, presence of tcdA, tcdB and binary toxins and detect new emerging types at local, national and European level. The primary objectives of the present study were to: (i) test the pilot protocol for the surveillance of CDI in European acute care hospitals developed by ECDIS-Net (methodology, variables and indicators); (ii) assess the feasibility and workload of collecting the required hospital data, case- based epidemiological and microbiological data; and (iii) evaluate the quality of data collected, whether in the presence or absence of existing national CDI surveillance activities. A secondary aim was to assess the relationship between patient and microbiological characteristics and in-hospital outcome of CDI to confirm the added value of collecting detailed epidemiological and microbiological data on CDI at European level

    Standardised surveillance of Clostridium Difficile Infection in European acute care hospitals: A pilot study, 2013

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    Clostridium difficile infection (CDI) remains poorly controlled in many European countries, of which several have not yet implemented national CDI surveillance. In 2013, experts from the European CDI Surveillance Network project and from the European Centre for Disease Prevention and Control developed a protocol with three options of CDI surveillance for acute care hospitals: a ‘minimal’ option (aggregated hospital data), a ‘light’ option (including patient data for CDI cases) and an ‘enhanced’ option (including microbiological data on the first 10 CDI episodes per hospital). A total of 37 hospitals in 14 European countries tested these options for a three-month period (between 13 May and 1 November 2013). All 37 hospitals successfully completed the minimal surveillance option (for 1,152 patients). Clinical data were submitted for 94% (1,078/1,152) of the patients in the light option; information on CDI origin and outcome was complete for 94% (1,016/1,078) and 98% (294/300) of the patients in the light and enhanced options, respectively. The workload of the options was 1.1, 2.0 and 3.0 person-days per 10,000 hospital discharges, respectively. Enhanced surveillance was tested and was successful in 32 of the hospitals, showing that C. difficile PCR ribotype 027 was predominant (30% (79/267)). This study showed that standardised multicountry surveillance, with the option of integrating clinical and molecular data, is a feasible strategy for monitoring CDI in Europe

    Immune cell subpopulations and serum neurofilament light chain are associated with increased risk of disease worsening in multiple sclerosis

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    Changes is lymphocyte subpopulations in peripheral blood have been proposed as biomarkers for evaluation of disease activity in multiple sclerosis (MS). Serum neurofilament light chain (sNfL) is a biomarker reflecting neuro-axonal injury in MS that could be used to monitor disease activity, response to drugs and to prognosticate disease course. Here we show a moderate correlation between sNfL and lymphocyte cell subpopulations, and our data furthermore suggest that sNfL and specific immune cell subpopulations together could predict future disease worsening in MS
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