43 research outputs found
New concept using Passive Infrared (PIR) technology for a contactless detection of breathing movement: a pilot study involving a cohort of 169 adult patients
Spallation reactions. A successful interplay between modeling and applications
The spallation reactions are a type of nuclear reaction which occur in space
by interaction of the cosmic rays with interstellar bodies. The first
spallation reactions induced with an accelerator took place in 1947 at the
Berkeley cyclotron (University of California) with 200 MeV deuterons and 400
MeV alpha beams. They highlighted the multiple emission of neutrons and charged
particles and the production of a large number of residual nuclei far different
from the target nuclei. The same year R. Serber describes the reaction in two
steps: a first and fast one with high-energy particle emission leading to an
excited remnant nucleus, and a second one, much slower, the de-excitation of
the remnant. In 2010 IAEA organized a worskhop to present the results of the
most widely used spallation codes within a benchmark of spallation models. If
one of the goals was to understand the deficiencies, if any, in each code, one
remarkable outcome points out the overall high-quality level of some models and
so the great improvements achieved since Serber. Particle transport codes can
then rely on such spallation models to treat the reactions between a light
particle and an atomic nucleus with energies spanning from few tens of MeV up
to some GeV. An overview of the spallation reactions modeling is presented in
order to point out the incomparable contribution of models based on basic
physics to numerous applications where such reactions occur. Validations or
benchmarks, which are necessary steps in the improvement process, are also
addressed, as well as the potential future domains of development. Spallation
reactions modeling is a representative case of continuous studies aiming at
understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie
Production of medically useful bromine isotopes via alpha-particle induced nuclear reactions
Two-dimensional plastic microlens arrays by deep lithography with protons: fabrication and characterization
IAEA coordinated research project on nuclear data for charged-particle monitor reactions and medical isotope production
An IAEA coordinated research project was launched in December 2012 to establish and improve the nuclear data required to characterise charged-particle monitor reactions and extend data for medical radionuclide production. An international team was assembled to undertake work addressing the requirements for more accurate cross-section data over a wide range of targets and projectiles, undertaken in conjunction with a limited number of measurements and more extensive evaluations of the decay data of specific radionuclides. These studies are nearing completion, and are briefly described below
Changing pattern of bacterial susceptibility to antibiotics in hematopoietic stem cell transplant recipients.
Adequate infection prophylaxis and empirical antibiotic therapy are of critical importance after hematopoietic stem cell transplantation (HSCT). We examined the evolution of bacterial susceptibility to antibiotics in 492 patients (198 allografts and 294 autografts) transplanted between 1982 and 1999 and evaluated whether ciprofloxacin prophylaxis and an empirical antibiotic regimen (glycopeptide + third-generation cephalosporin) were still valid. We collected all susceptibility tests performed during the initial hospitalization on blood cultures as well as routine surveillance cultures and analyzed susceptibility to ciprofloxacin and to major antibiotics used in our unit. Gram-positive cocci rapidly became resistant to ciprofloxacin (susceptibility around 70% in 1990 to less than 20% in 1998) but sensitivity to glycopeptides remained unaltered. There was a rapid decline in the number of patients colonized with Gram-negative bacilli in the early years of ciprofloxacin prophylaxis. However, susceptibility to ciprofloxacin fell sharply from around 90% in 1990 to around 30% in 1999. In parallel, susceptibility to ceftazidime also decreased to less than 80% in recent years. Piperacillin (+/- tazobactam) did not show any variation over time and its efficacy remained too low (about 60%). Imipenem as well as recently introduced cefepim and meropenem showed stable and excellent profiles (>90% susceptibility). In conclusion: (1) quinolone prophylaxis has now lost most of its value; (2) the choice of a third-generation cephalosporin for empirical antibiotic therapy may no longer be the best because of the emergence of Gram-negative strains resistant to beta-lactamases, such as Enterobacter sp. More appropriate regimens of empirical antibiotic therapy in HSCT recipients may be based on the use of a carbapenem or fourth-generation cephalosporin
Actualités thérapeutiques dans la thrombocytémie essentielle
Essential thrombocythemia is a myeloproliferative disorder affecting megakaryocyte and is characterized by frequent thrombotic or hemorrhagic complications. In young patients, the optimal management of thrombocythaemia is controversial. Since th relationship of thrombosis and hemorrhage to platelet counts is not demonstrated, ther is no clear inidcation for using drugs capable of lowering platelet counts in young asymptomatic subjects. However, treatment should be offered to patients with a definite high risk of major or life-threatening hemostatic complications. The present paper reviews the incidence and risk factors for thrombotic complications and the use of medications inhibiting platelet production
Intérêt de l'acide rétinoïque "tous trans" dans le traitement de la leucémie aiguë promyélocytaire
Clinical case of the month. The association of Hodgkin's disease and nephrotic syndrome
peer reviewedThe nephrotic syndrome is a rare complication of Hodgkin's disease. The majority of the cases do not respond to corticosteroids but are cured by the treatment of the lymphoma. We describe a patient with a nephrotic syndrome at the time of diagnosis of mixed cellularity Hodgkin's disease and the resolution of this nephrotic syndrome by MOPP-ABV chemotherapy