RESUMEN
In 2002, an innovative neutron time-of-flight facility started operation at CERN: n_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n_TOF is presented, together with plans for new measurements related to nuclear industry.
Asunto(s)
Terapia por Captura de Neutrón/instrumentación , Terapia por Captura de Neutrón/métodos , Reactores Nucleares , Diseño de Equipo , Análisis de Falla de Equipo , Neutrones , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Congenital heart disease is often severe and outcome remains uncertain. In some cases, early intervention at birth can improve the prognosis. Prenatal detection of congenital heart disease by ultrasound may improve outcome for foetuses with congenital heart disease but today, results are not convincing. The purpose of this review was to describe the detection of congenital heart disease in a non selected population. METHODS: A retrospective study was undertaken to evaluate the prenatal detection of congenital heart disease in our department from 1984 to 2003. RESULTS: Incidence of congenital heart disease was 4.9. Sensitivity of detection was 60%, specificity was 99.9%. Most cases were severe heart diseases. In 57 fetuses (40%), congenital heart disease was not detected. Thirty-seven fetuses (65%) presented minor disease; in 20 fetuses (35%), congenital heart disease was found to be severe. Effectiveness of detection of major congenital heart diseases has increased since 2000. CONCLUSION: Large-scale fetal heart screening is necessary for early detection of congenital heart disease and improved outcome.
Asunto(s)
Cardiopatías Congénitas/diagnóstico , Femenino , Humanos , Recién Nacido , Valor Predictivo de las Pruebas , Embarazo , Diagnóstico Prenatal , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.
Asunto(s)
Enfermedades del Recién Nacido/prevención & control , Juego de Reactivos para Diagnóstico , Infecciones Estreptocócicas/diagnóstico , Streptococcus agalactiae/aislamiento & purificación , Vaginitis/microbiología , Adulto , Femenino , Humanos , Recién Nacido , Embarazo , Infecciones Estreptocócicas/prevención & control , Factores de TiempoRESUMEN
This report describes a prenatal diagnosis of intraspinal lipoma. This pathology, not well known by obstetricians, forms a part of neural tube defects. Echographic aspect, embryologic origin, differential diagnosis, neurosurgical prognosis and treatment are reviewed and discussed.