105 research outputs found

    Evaluation and optimization of the Sysmex UF1000i system for the screening of urinary tract infection in primary health care elderly patients

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    Objective Urinary tract infections (UTIs) are a common problem in the elderly population. Urine culture is still considered the "gold standard" to diagnose infection in this population. However, urine cultures are laborious and costly, and most samples will yield no growth. Methods An evaluation was made of the Sysmex UF-1000i flow cytometer as a screening tool for UTI in an elderly population older than 65 years who lived in the community, using 346 urine samples submitted for culture. Results The Receiver Operating Characteristic (ROC) analysis showed a significant difference (P < 0.01) between 0.98 bacteria area under the curve value and 0.82 of white blood cells (WBC). The combination of both counts for screening did not show any improvement in specificity or sensitivity. According to our data, the use of a single cut-off point of 200 bacteria/μL is suggested, in which the sensitivity and specificity were 99.11% and 91.59%, respectively, with a NPV of 99.49%. Moreover, this cut-off value could avoid 60.24% of the samples to be cultured, with a minimal false negative results rate of 0.87%. Conclusions The stratification of age groups stratification helps in selecting a more adjusted Sysmex UF1000i cut-off limit, leading to an improvement in the screening parameters that would imply a better management of these infections, as well as a high reduction in the workload and cost savings

    Time-of-flight and activation experiments on 147Pm and 171Tm for astrophysics

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    The neutron capture cross section of several key unstable isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n,γ) measurement, for which high neutron fluxes and effective background rejection capabilities are required. As part of a new program to measure some of these important branching points, radioactive targets of 147Pm and 171Tm have been produced by irradiation of stable isotopes at the ILL high flux reactor. Neutron capture on 146Nd and 170Er at the reactor was followed by beta decay and the resulting matrix was purified via radiochemical separation at PSI. The radioactive targets have been used for time-of-flight measurements at the CERN n-TOF facility using the 19 and 185 m beam lines during 2014 and 2015. The capture cascades were detected using a set of four C6D6 scintillators, allowing to observe the associated neutron capture resonances. The results presented in this work are the first ever determination of the resonance capture cross section of 147Pm and 171Tm. Activation experiments on the same 147Pm and 171Tm targets with a high-intensity 30 keV quasi-Maxwellian flux of neutrons will be performed using the SARAF accelerator and the Liquid-Lithium Target (LiLiT) in order to extract the corresponding Maxwellian Average Cross Section (MACS). The status of these experiments and preliminary results will be presented and discussed as well

    Characterization of the n-TOF EAR-2 neutron beam

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    The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n-TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam prole and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash

    Measurement of the 240Pu(n,f) cross-section at the CERN n-TOF facility : First results from experimental area II (EAR-2)

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    The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n-TOF facility relative to the well-known 235U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n-TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1). Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented

    New measurement of the 242Pu(n,γ) cross section at n-TOF-EAR1 for MOX fuels : Preliminary results in the RRR

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    The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with 238U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of 242Pu, the previous neutron capture cross section measurements were made in the 70's, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its "High Priority Request List" and its report WPEC-26 that the capture cross section of 242Pu should be measured with an accuracy of at least 7-12% in the neutron energy range between 500 eV and 500 keV. This work presents a brief description of the measurement performed at n-TOF-EAR1, the data reduction process and the first ToF capture measurement on this isotope in the last 40 years, providing preliminary individual resonance parameters beyond the current energy limits in the evaluations, as well as a preliminary set of average resonance parameters

    DEVELOPING TECHNICAL ENGLISH SKILLS FOR CIVIL ENGINEERING STUDENTS

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    Traditionally, Spanish schools of civil engineering provide their students a class on “Technical English” in order to develop their language skills. However, this class does not cover all the skills that the student would need in the labor market and mainly focuses in the reading and writing skills, and in a lower degree in the speaking and listening ones. This paper proposes a series of innovative and informal training activities, such as cine-forum on technical civil engineering topics and role playing on real professional situations, that allow Spanish civil engineering students to develop English skills, that can rarely be worked in the classroom (i.e. speaking, negotiating and conversing), which encourage debate, participation, and foster their self-confidence to speak about technical-English topics in public. Although the students’ level of English is much lower than expected, they all agree on the importance of technical English for their future career. The results also show the students’ lack in skills that are difficult to train in regular classes (speaking and talking). Consequently, this situation would require to provide complementary activities like the ones suggested in this project in order to develop these skills and increase the students’ demand for engineering classes taught in English

    The measurement programme at the neutron time-of-flight facility n-TOF at CERN

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    Neutron-induced reaction cross sections are important for a wide variety of research fields ranging from the study of nuclear level densities, nucleosynthesis to applications of nuclear technology like design, and criticality and safety assessment of existing and future nuclear reactors, radiation dosimetry, medical applications, nuclear waste transmutation, accelerator-driven systems and fuel cycle investigations. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. CERN's neutron time-of-flight facility n-TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at n-TOF will be presented

    Ruxolitinib in refractory acute and chronic graft-versus-host disease : a multicenter survey study

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    Graft-versus-host disease is the main cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. First-line treatment is based on the use of high doses of corticosteroids. Unfortunately, second-line treatment for both acute and chronic graft-versus-host disease, remains a challenge. Ruxolitinib has been shown as an effective and safe treatment option for these patients. Seventy-nine patients received ruxolitinib and were evaluated in this retrospective and multicenter study. Twenty-three patients received ruxolitinib for refractory acute graft-versus-host disease after a median of 3 (range 1-5) previous lines of therapy. Overall response rate was 69.5% (16/23) which was obtained after a median of 2 weeks of treatment, and 21.7% (5/23) reached complete remission. Fifty-six patients were evaluated for refractory chronic graft-versus-host disease. The median number of previous lines of therapy was 3 (range 1-10). Overall response rate was 57.1% (32/56) with 3.5% (2/56) obtaining complete remission after a median of 4 weeks. Tapering of corticosteroids was possible in both acute (17/23, 73%) and chronic graft-versus-host disease (32/56, 57.1%) groups. Overall survival was 47% (CI: 23-67%) at 6 months for patients with aGVHD (62 vs 28% in responders vs non-responders) and 81% (CI: 63-89%) at 1 year for patients with cGVHD (83 vs 76% in responders vs non-responders). Ruxolitinib in the real life setting is an effective and safe treatment option for GVHD, with an ORR of 69.5% and 57.1% for refractory acute and chronic graft-versus-host disease, respectively, in heavily pretreated patients

    Symptom-related screening programme for early detection of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: the SYSPPE study

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    Background Chronic thromboembolic pulmonary hypertension (CTEPH) is the most severe long-term complication of acute pulmonary embolism (PE). We aimed to evaluate the impact of a symptom screening programme to detect CTEPH in PE survivors.Methods This was a multicentre cohort study of patients diagnosed with acute symptomatic PE between January 2017 and December 2018 in 16 centres in Spain. Patients were contacted by phone 2 years after the index PE diagnosis. Those with dyspnoea corresponding to a New York Heart Association (NYHA)/WHO scale≥II, visited the outpatient clinic for echocardiography and further diagnostic tests including right heart catheterisation (RHC). The primary outcome was the new diagnosis of CTEPH confirmed by RHC.Results Out of 1077 patients with acute PE, 646 were included in the symptom screening. At 2 years, 21.8% (n=141) reported dyspnoea NYHA/WHO scale≥II. Before symptom screening protocol, five patients were diagnosed with CTEPH following routine care. In patients with NYHA/WHO scale≥II, after symptom screening protocol, the echocardiographic probability of pulmonary hypertension (PH) was low, intermediate and high in 76.6% (n=95), 21.8% (n=27) and 1.6% (n=2), respectively. After performing additional diagnostic test in the latter 2 groups, 12 additional CTEPH cases were confirmed.Conclusions The implementation of this simple strategy based on symptom evaluation by phone diagnosed more than doubled the number of CTEPH cases. Dedicated follow-up algorithms for PE survivors help diagnosing CTEPH earlier.Thrombosis and Hemostasi

    Measurement of the 72Ge(n,γ) cross section over a wide neutron energy range at the CERN n_TOF facility

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    The Ge72(n,γ) cross section was measured for neutron energies up to 300keV at the neutron time-of-flight facility n_TOF (CERN), Geneva, for the first time covering energies relevant to heavy-element synthesis in stars. The measurement was performed at the high-resolution beamline EAR-1, using an isotopically enriched GeO272 sample. The prompt capture γ rays were detected with four liquid scintillation detectors, optimized for low neutron sensitivity. We determined resonance capture kernels up to a neutron energy of 43keV, and averaged cross sections from 43 to 300keV. Maxwellian-averaged cross section values were calculated from kT=5 to 100keV, with uncertainties between 3.2% and 7.1%. The new results significantly reduce uncertainties of abundances produced in the slow neutron capture process in massive stars
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