545 research outputs found
¿Es útil la disuria para el diagnóstico de la infección del tracto urinario?
ObjetivoDeterminar la validez de criterio y el valor predictivo del síntoma disuria para el diagnóstico de infección del tracto urinario (ITU).DiseñoEstudio transversal para evaluación de un síntoma.EmplazamientoSeis consultas de atención primaria (4 de zona urbana y 2 rurales) del Área 11 de Salud de Madrid.ParticipantesSe incluyeron 232 pacientes mayores de 14 años que acudieron a consulta durante 6 meses consecutivos (116 consultaron por disuria y 116 asintomáticos para el síntoma disuria). A todos se les solicitó sedimento y urocultivo.Mediciones y resultadosSe estableció diagnóstico de ITU con urocultivo positivo o sedimento con leucocituria y bacteriuria. Se estudio la sensibilidad (S), especificidad (E), el valor predictivo positivo (VPP), el valor predictivo negativo (VPN), el cociente de probabilidades positivo (CPP) y el cociente de probabilidades negativo (CPN) de la disuria para el diagnóstico de ITU. La edad media fue de 54 años (rango, 19–82), siendo un 73% mujeres. No había diferencias significativas de edad y sexo entre casos y no casos (p > 0,1). La disuria mostró una S del 96% (IC del 95%, 86–98%), una E del 69% (IC del 95%, 61–76%) y un CPP de 3,1 (IC del 95%, 2,7–3,5) para el diagnóstico de ITU. En el subgrupo de mujeres la S fue del 95% (IC del 95%, 84–99%) y la E del 67% (IC del 95%, 58–75%). Se calculó para este síntoma un VPP del 30% (IC del 95%, 22–40%) y un VPN del 99% (IC del 95%, 95–100%).ConclusionesEs poco probable el diagnóstico de ITU sin el síntoma disuria. La mayoría de los pacientes con ITU presentan disuria; sin embargo, este síntoma aislado no nos permite establecer el diagnostico de infección urinaria.ObjectiveTo assess the validity of criterion and predictive value of dysuria for the diagnosis of UTI.DesignCross-sectional study to assess a symptom.SettingSix general medicine clinics (four urban clinics and two rural clinics) in the 11th Health Area in Madrid.PatientsThe sample consists of 232 patients aged above fourteen who consulted during six consecutive months (116 of them reported having dysuria and 116 were asymptomatic).Measurements and main resultsThe diagnosis of urinary tract infections (UTI) was achieved through positive urine cultures or bacteriuria and leukocyturia in the centrifuged urine sediment. The sensitivity (S) of dysuria analysis for the diagnosis of UTI, its specifity (E), its predictive value (VP), and its probability coeficient (CP) were considered. Average age of the sample was 54 years old (range 19–82); 73% of the patients were female. No statistically significative difference of sex and age was found between cases and non-cases (p > 0.1). Dysuria showed a 96% of sensitivity (95% CI, 86–98%), a 69% of E (95% CI, 61–76%) and 3.1 of CPP (95% CI, 2.7–3.5) for UTI diagnosis. In the women subgroup there was 95% of sensitivity (95% CI, 84–99%) and 67% of E (95% CI, 58–75%). A positive predictive value of 30% (95% CI, 22–40) and a negative predictive value of 99% (95% CI, 95–100) were estimated for this symptom.ConclusionsThe diagnosis of urinary tract infections is unlikely in the absence of dysuria, but to treat all dysuria patients as UTI entails a high rate of overtreatment
No evidence that wild red deer (Cervus elaphus) on the Iberian Peninsula are a reservoir of Mycobacterium avium subspecies paratuberculosis infection
The potential role of red deer (Cervus elaphus) as a reservoir of Mycobacterium avium subspecies paratuberculosis (MAP) infection is largely unknown. A total of 332 wild red deer were investigated using post-mortem examination, bacteriology and serology. Only three animals (1.12%) were found to have lesions on histopathological examination and no MAP bacteria were recovered on culture. The results suggest it is unlikely that wild red deer make a significant contribution to the maintenance of MAP infection in the region. The cross-reactivity of the ELISAs used indicates this diagnostic modality is ineffective in the detection of MAP infection in this species. The implications of these results for the control of this important pathogen in both livestock and wildlife are discussed
Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar
Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4-6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tetheredballoon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2-3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds
NEXT-100 Technical Design Report (TDR). Executive Summary
In this Technical Design Report (TDR) we describe the NEXT-100 detector that
will search for neutrinoless double beta decay (bbonu) in Xe-136 at the
Laboratorio Subterraneo de Canfranc (LSC), in Spain. The document formalizes
the design presented in our Conceptual Design Report (CDR): an
electroluminescence time projection chamber, with separate readout planes for
calorimetry and tracking, located, respectively, behind cathode and anode. The
detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or
100 kg at 10 bar. This option builds in the capability to increase the total
isotope mass by 50% while keeping the operating pressure at a manageable level.
The readout plane performing the energy measurement is composed of Hamamatsu
R11410-10 photomultipliers, specially designed for operation in low-background,
xenon-based detectors. Each individual PMT will be isolated from the gas by an
individual, pressure resistant enclosure and will be coupled to the sensitive
volume through a sapphire window. The tracking plane consists in an array of
Hamamatsu S10362-11-050P MPPCs used as tracking pixels. They will be arranged
in square boards holding 64 sensors (8 times8) with a 1-cm pitch. The inner
walls of the TPC, the sapphire windows and the boards holding the MPPCs will be
coated with tetraphenyl butadiene (TPB), a wavelength shifter, to improve the
light collection.Comment: 32 pages, 22 figures, 5 table
Radon and material radiopurity assessment for the NEXT double beta decay experiment
The Neutrino Experiment with a Xenon TPC (NEXT), intended to investigate the
neutrinoless double beta decay using a high-pressure xenon gas TPC filled with
Xe enriched in 136Xe at the Canfranc Underground Laboratory in Spain, requires
ultra-low background conditions demanding an exhaustive control of material
radiopurity and environmental radon levels. An extensive material screening
process is underway for several years based mainly on gamma-ray spectroscopy
using ultra-low background germanium detectors in Canfranc but also on mass
spectrometry techniques like GDMS and ICPMS. Components from shielding,
pressure vessel, electroluminescence and high voltage elements and energy and
tracking readout planes have been analyzed, helping in the final design of the
experiment and in the construction of the background model. The latest
measurements carried out will be presented and the implication on NEXT of their
results will be discussed. The commissioning of the NEW detector, as a first
step towards NEXT, has started in Canfranc; in-situ measurements of airborne
radon levels were taken there to optimize the system for radon mitigation and
will be shown too.Comment: Proceedings of the Low Radioactivity Techniques 2015 workshop
(LRT2015), Seattle, March 201
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Demonstration of the event identification capabilities of the NEXT-White detector
In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies. [Figure not available: see fulltext.
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