1,486 research outputs found
Theoretical treatments of fusion processes in collisions of weakly bound nuclei
We review the theoretical methods to evaluate fusion cross sections in
collisions of weakly bound nuclei. We piont out that in such collisions the
coupling to the breakup channel leads to the appearance of different fusion
processes. The extentsion of the coupled-channel method to coupling with the
continuum is the most successful treatment for these collisions. However,
evaluating separate cross section for each fusion process remains a very hard
task.Comment: 8 pages, 3 figures. Invited talk (LFC) at the IX International
Conference on Nucleus-Nucleus Collisions, Rio de Janeiro, August 28-
September 1, 2006. Nuclear Physics A, in pres
6Li direct breakup lifetimes
alpha-d coincidence data were studied for the 6Li + 59Co reaction at E(lab) =
29.6 MeV. By using a kinematic analysis, it was possible to identify which
process, leading to the same final state, has the major contribution for each
of the selected angular regions. Contributions of the 6Li sequential and direct
breakup to the incomplete fusion/transfer process were discussed by considering
the lifetimes obtained by using a semiclassical approach, for both breakup
components.Comment: 5 pages, 4 figures, Invited Talk (Parrallel Sessions) of A. Szanto de
Toledo, prepared for the Proccedings of the 10th International Conference on
Nucleus-Nucleus Collisions, August 16-21, 2009, Beijing, China; submitted to
Nucl. Phys. A (Proceedings of NN2009
Elastic Scattering and Total Reaction Cross Section for the 6He + 27Al System
The elastic scattering of the radioactive halo nucleus 6He on 27Al target was
measured at four energies close to the Coulomb barrier using the RIBRAS
(Radioactive Ion Beams in Brazil) facility. The Sao Paulo Potential(SPP) was
used and its diffuseness and imaginary strength were adjusted to fit the
elastic scattering angular distributions. Reaction cross-sections were
extracted from the optical model fits. The reduced reaction cross-sections of
6He on 27Al are similar to those for stable, weakly bound projectiles as
{6,7}Li, 9Be and larger than stable, tightly bound projectile as 16O on 27Al.Comment: 7 pages, 1 table, 3 figure
Projectile breakup dynamics for Li + Co: kinematical analysis of - coincidences
A study of the kinematics of the - coincidences in the Li +
Co system at a bombarding energy of MeV is presented.
With exclusive measurements performed over different angular intervals it is
possible to identify the respective contributions of the sequential projectile
breakup and direct projectile breakup components. A careful analysis using a
semiclassical approach of these processes provides information on both their
lifetime and their distance of occurrence with respect to the target. Breakup
to the low-lying (near-threshold) continuum is delayed, and happens at large
internuclear distances. This suggests that the influence of the projectile
breakup on the complete fusion process can be related essentially to direct
breakup to the Li high-lying continuum spectrum. %Comment: Revised version including new Fig.3 and Fig.4 with new CDCC
calculations. Accepted for publication at Eur. Phys. Jour. A. 11 pages, 6
figure
Allergic Reactions to Metamizole: Immediate and Delayed Responses
[EN] Background: Pyrazolones are the most common causes of
selective nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity.
We studied a large group of patients with immediate
and delayed selective responses to metamizole.
Methods: Patients with suspicion of hypersensitivity to metamizole
were evaluated. We verified acetylsalicylic acid tolerance
and classified patients as immediate or delayed responders
if they showed symptoms less or more than 24 h
after metamizole administration. Skin tests were performed
and if negative, a basophil activation test (BAT) was performed
on immediate responders. If it was negative, we performed
a drug provocation test (DPT) with metamizole. Results:
A total of 137 patients were included: 132 reacted
within 24 h (single NSAID-induced urticaria/angioedema/
anaphylaxis; SNIUAA) and 5 after 24 h (single NSAID-induced
delayed hypersensitivity reaction; SNIDHR). Most SNIUAA
patients developed anaphylaxis (60.60%); for SNIDHR, maculopapular
exanthema was the most frequent entity (60%).
Skin testing was positive in 62.04% of all cases and BAT in 28% of the SNIUAA patients with negative skin tests. In 5.1%
of the cases, DPT with metamizole was needed to establish
the diagnosis. In 22.62% of the cases, diagnosis was established
by consistent and unequivocal history of repeated allergic
episodes in spite of a negative skin test and BAT. Conclusions:
SNIUAA to metamizole is the most frequent type of
selective NSAID hypersensitivity, with anaphylaxis being the
most common clinical entity. It may occur within 1 h after
drug intake. SNIDHR occurs in a very low percentage of cases.
The low sensitivity of diagnostic tests may be due to incomplete
characterization of the chemical structures of metamizole
and its metabolites.The present study has been supported by the Institute of Health ‘Carlos III’ of the Ministry of Economy and Competitiveness [grants cofounded by European Regional Development Fund (ERDF), Red de Reacciones Adversas a Alergenos y Farmacos (RD12/0013/0001 and PI15/01317)] and by Consejeria de Salud de la Junta de Andalucía (PI-0463-2013).Blanca-López, N.; Pérez-Sanchez, N.; Agúndez, JA.; García-Martín, E.; Torres, MJ.; Cornejo-Garcia, JA.; Perkins, JR.... (2016). Allergic Reactions to Metamizole: Immediate and Delayed Responses. International Archives of Allergy and Immunology. 169(4):223-230. https://doi.org/10.1159/000444798S223230169
Reaction mechanisms in the 6Li+59Co system
The reactions induced by the weakly bound 6Li projectile interacting with the
intermediate mass target 59Co were investigated. Light charged particles
singles and - coincidence measurements were performed at the near
barrier energies E_lab = 17.4, 21.5, 25.5 and 29.6 MeV. The main contributions
of the different competing mechanisms are discussed. A statistical model
analysis, Continuum-Discretized Coupled-Channels calculations and two-body
kinematics were used as tools to provide information to disentangle the main
components of these mechanisms. A significant contribution of the direct
breakup was observed through the difference between the experimental sequential
breakup cross section and the CDCC prediction for the non-capture breakup cross
section.Comment: 30 pages, 8 figure
About Low DFR for QC-MDPC Decoding
International audienceMcEliece-like code-based key exchange mechanisms using QC-MDPC codes can reach IND-CPA security under hardness assumptions from coding theory, namely quasi-cyclic syndrome decoding and quasi-cyclic codeword finding. To reach higher security requirements, like IND-CCA security, it is necessary in addition to prove that the decoding failure rate (DFR) is negligible, for some decoding algorithm and a proper choice of parameters. Getting a formal proof of a low DFR is a difficult task. Instead, we propose to ensure this low DFR under some additional security assumption on the decoder. This assumption relates to the asymptotic behavior of the decoder and is supported by several other works. We define a new decoder, Backflip, which features a low DFR. We evaluate the Backflip decoder by simulation and extrapolate its DFR under the decoder security assumption. We also measure the accuracy of our simulation data, in the form of confidence intervals, using standard techniques from communication systems
Hypersensitivity to Nonsteroidal Anti-inflammatory Drugs in Children and Adolescents: Cross-Intolerance Reactions.
Journal Article; Research Support, Non-U.S. Gov't; Review;Nonsteroidal anti-inflammatory drugs (NSAIDs) are used worldwide and are responsible for several types of drug hypersensitivity reactions (DHRs) in all age groups. The 2 major groups of DHRs to NSAIDs are those induced by immunological mechanisms (selective reactions) and those where inflammatory mediators are released through activation of the prostaglandin-leukotriene pathway without specific immunological recognition (cross-intolerance). In the present review, we focus on cross-intolerance reactions, which are the most frequent DHRs and are becoming a topic of major interest in children and adolescents. Paracetamol and ibuprofen are the drugs that most frequently cause DHRs in children; other NSAIDs are responsible for reactions in adolescents. In vivo and in vitro tests are of limited diagnostic value, with some exceptions for the less common selective reactions. In cross-intolerance, the clinical history and controlled administration are in many instances the only way to establish a diagnosis and look for alternatives. The clinical history is diagnostic when consistent symptoms occur repeatedly after exposure to NSAIDs with different chemical structures. Cutaneous and respiratory symptoms often co-occur in young children. The natural history of these reactions in children is unknown, and some patients can develop tolerance over time. Atopy remains a major risk factor for cross-intolerant reactions. The increasing interest in hypersensitivity to NSAIDs with improvements in patient phenotyping and the information provided by pharmacogenetics will improve our understanding and management of these reactions in the near future.The present study was supported by grants from the Carlos III National Health Institute RD12/0013 (RIRAAF Network), FIS PI12/02247,
and FIS PI13/02598. It was also supported by Marie Curie (IAPP 7th Framework Program Mr. SymBioMath, no. 324554) and the Andalusian Public Health Service (PI-0279-2012 and
PI-0463-2013).YesLos antiinflamatorios no esteroideos (AINEs) son ampliamente utilizados en todo el mundo y en todos los tramos de edad. Son responsables de un número importante de reacciones de hipersensibilidad a fármacos (RHFs), que no sólo afectan a adultos sino también a niños y adolescentes. Existen dos grandes grupos: reacciones selectivas, inducidas por mecanismos inmunológicos específicos, y de intolerancia cruzada (IC), donde se liberan mediadores inflamatorios en ausencia de reconocimiento inmunológico específico. En esta revisión nos ocuparemos de la IC, que es la causa más frecuente de RHFs y resulta de gran interés en niños y adolescentes. El paracetamol y el ibuprofeno son los medicamentos más frecuentemente implicados en las RHFs en niños. El uso diagnóstico de los tests in vivo e in vitro es muy limitado, con algunas excepciones en las reacciones selectivas. En las de IC, la historia clínica y la administración controlada son en ocasiones la única vía para confirmar el diagnóstico y determinar las alternativas terapéuticas más adecuadas. La historia clínica tiene valor diagnóstico cuando se reproducen síntomas consistentes repetidamente tras la exposición a AINEs no relacionados estructuralmente. En niños de corta edad es especialmente frecuente la combinación de síntomas cutáneos y respiratorios. Aunque se desconoce la historia natural de la IC en niños, es probable que se desarrolle tolerancia a lo largo de la vida. El fenotipado detallado junto con la información proporcionada por la fármaco-genética no sólo proporcionarán un conocimiento más preciso de la IC sino que también facilitará el manejo clínico de estos pacientes
Soft drink intake is associated with weight gain, regardless of physical activity levels: The health workers cohort study
Background: While soft drink intake is positively associated with weight gain, no previous study has investigated whether leisure-time physical activity modifies this association. We estimated the association between soft drink intake and body weight, and explored if this association differed by levels of leisure-time physical activity. Methods: We used data from the health workers cohort study, a prospective study of Mexican adults (20 to 85y old), including 1268 health workers and their families, who were assessed at baseline (2004-2006) and follow-up (2010-2012). We assessed soft drink intake (cola and flavored soda) using a validated food frequency questionnaire. We measured leisure-time physical activity using a self-report questionnaire, and categorized according to the 2010 World Health Organization (WHO) recommendations. Body weight was measured by trained personnel. The association between changes in soft drink intake and weight change, and if such association varied by levels of physical activity was estimated through fixed-effect models. Results: An increase in one serving per day of soft drink was associated with 0.10 kg (95% CI 0.00, 0.19) increase in weight per year. This association was not modified by leisure-time physical activity, as demonstrated by the magnitude of the coefficient of the interaction between soft drink, leisure-time physical activity, and time (-0.03 kg, 95% CI-0.27 to 0.21); people who complied with the WHO physical activity recommendations gained 0.36 kg/year per serving of soft drink, compared to 0.48 kg/year for people without sufficient physical activity. Conclusions: Soft drink intake was associated with weight gain. Leisure-time physical activity did not modify the association between soft drink intake and weight gain. This finding challenges the idea that leisure-time physical activity is sufficient to counterbalance weight gain associated to soft drink intake
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