Introdução: O hematoma subdural agudo não traumático é uma entidade rara em Pediatria. A presença de sintomas neurológicos de instalação aguda associada a anticoagulação obriga à exclusão desta entidade. Caso clínico: Apresentamos o caso de uma criança, do sexo masculino, de sete anos de idade, com prótese mitral mecânica, medicada com varfarina, que recorreu ao serviço de urgência por cefaleias intensas e prog...
Objective: The epilepsies associated with the tuberous sclerosis complex (TSC) are very often refractory to medical therapy. Surgery for epilepsy is an effective alternative when the critical link between the localization of seizure onset in the scalp and a particular cortical tuber can be established. In this study we perform analysis of ictal and interictal EEG to improve such link. Methods: The ictal and int...
A new technique is described for measuring the drift velocities and mobilities of noble gas ions in noble gases that makes use of a gaseous electron multiplier (GEM) and a UV flash lamp to produce the ions in a thin, well-defined, planar region. The drift velocities are determined from measurements of the transit time of the ions in crossing the drift space. We present experimental results for xenon ions in xen...
The neutron time-of-flight facility n_TOF at CERN, fully operational since 2002, combines a high instantaneous neutron flux with high energy resolution. The wide energy range and the high neutron flux per time-of-flight burst result in a much enhanced signal to background ratio for neutron capture of radioactive isotopes and makes this facility well suited for the measurement of high quality neutron-induced rea...
The [beta]-decay of 187Re represents a suited cosmo-chronometer for the age of the r-process abundances, since the radiogenic part of the daughter isotope 187Os is defined by the difference between the solar 187Os abundance and s-process contribution to 187Os. The latter component can be determined via the s-process systematics based on the stellar neutron capture cross sections of 186Os and 187Os. The laborato...
The effect of the presence of a drift electric field on the response of gaseous and semiconductor radiation detectors to energetic X-rays (energies from 20 to 200 keV) is investigated using the PENELOPE code to simulate the photo-absorption and the slow-down of the electrons produced in Si, Ge, and Xe gas at 1 atm. For typical drift fields, the energy deposited in the detection media is calculated taking into a...
RESUMO Introdução: A craniossinostose é uma condição patológica que resulta do encerramento precoce de uma ou várias suturas cranianas, podendo, para além da questão estética, levar ao aparecimento de complicações neurológicas, mais frequente quando existe envolvimento de mais de uma sutura. Descrição dos Casos: Os autores apresentam dois casos clínicos de craniossinostose, com diferentes tempos de seguimento, ...
A series of neutron capture cross section measurements of interest to nuclear astrophysics have been recently performed at n_TOF, the neutron spallation source operating at CERN. The low repetition frequency of the proton beam driver, the extremely high instantaneous neutron flux, and the low background conditions in the experimental area are optimal for capture cross section measurements on low-mass or radioac...
A small-mass system has been developed for monitoring the flux of neutrons with energy up to 1 MeV at the new time-of-flight facility at CERN, n_TOF. The monitor is based on a thin Mylar foil with a 6Li deposit, placed in the neutron beam, and an array of Silicon detectors, placed outside the beam, for detecting the products of the 6Li(n, alpha)³H reaction. The small amount of material on the beam ensures a min...
Compton scatter imaging (CSI) is well establish one-sided imaging approach, where the image is formed using photons that are singly scattered in a region of the object. However, the measured data includes also photons that are multiply scattered and is also affected by the fact that incoming and outgoing beams are attenuated. In this paper, the EGS4 code system is used to gain some insight into the physics that...
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