83 research outputs found

    The Scientific program with RIBRAS (Radioactive Ion Beams in Brasil)

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    The Radioactive Ion Beams Facility (RIBRAS) is in operation since 2004 at the Pelletron Accelerator Laboratory of the University of São Paulo and consists of two superconducting solenoids capable of producing low energy secondary beams of light exotic nuclei. Measurements of the elastic scattering, breakup and transfer reactions with radioactive projectiles such as 6He, 8Li, 7Be on several targets have been performed. A review of the research program carried on along the last four years using the RIBRAS facility is presented

    Fibroids not encroaching the endometrial cavity and IVF success rate : a prospective study

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    BACKGROUND The impact of fibroids, not encroaching the endometrial cavity, have on the rate of success of IVF is still controversial. Recent meta-analyses suggest a detrimental effect of intramural lesions but not subserosal lesions. However, they also emphasize the need for further evidence. In order to elucidate this, we designed a prospective cohort study to compare the rate of success of IVF in women with and without fibroids. METHODS Exposed women were those with asymptomatic intramural or subserosal fibroids with a diameter below 50 mm and who were selected for IVF. Unexposed women were those free of fibroids, who were matched to cases by age and number of previous IVF cycles. All recruited patients underwent hystero-sonography to rule out intra-cavitary lesions. RESULTS There were 119 cases and 119 controls recruited. The number of clinical pregnancies in women with and without fibroids was 28 (24%) and 22 (19%), respectively (P= 0.43). The adjusted odds ratio (OR) for pregnancy in affected women was 1.38 [95% confidence interval (CI): 0.73-2.60]. The number of deliveries was 22 (18%) and 16 (13%), respectively (P= 0.38). The adjusted OR was 1.45 (95% CI: 0.71-2.94). Similar results emerged when focusing exclusively on women carrying intramural lesions (n= 80 couples). There was no significant relationship between clinical outcome and either the number or size of the fibroids. CONCLUSIONS In asymptomatic patients selected for IVF, small fibroids not encroaching the endometrial cavity did not impact on the rate of success of the procedure

    Understanding the mechanisms of nuclear collisions: A complete study of the B 10 + Sn 120 reaction

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    Background: Reactions involving exotic and stable weakly bound nuclei have been extensively studied in recent years. Although several models have been successfully used to explain particular reaction outcomes, the answers to many questions remain elusive. In previous works, we presented elastic, inelastic, and transfer angular distributions for the B10+Sn120 system measured at ELab=31.5, 33.0, 35.0, and 37.5 MeV. The data set was analyzed through coupled reaction channels calculations in the context of the double-folding São Paulo potential. Purpose: We investigate nuclear reaction mechanisms for systems involving weakly bound projectiles. Method: Angular distributions for several nuclear reaction processes were measured for the B10+Sn120 system at ELab=39.70 MeV. Results: The new data set involves angular distributions for elastic scattering, projectile and target inelastic excitations, one-neutron pickup transfer, one-proton stripping transfer, deuteron pickup transfer, and He3,4 stripping transfer. We have also observed Be10 nuclei. The effect of the couplings to some nonelastic states on the angular distributions is discussed. Conclusion: The theoretical calculations within the coupled reaction channels formalism provide an overall good agreement with the corresponding inelastic, one-neutron stripping, one-proton pickup, one-deuteron pickup, and He3 stripping transfer data. However, to improve the description of the elastic scattering angular distribution, the inclusion of additional channels in the coupling scheme might be necessary.Fil: Gasques, L. R.. Universidade de Sao Paulo; BrasilFil: Alvarez, M. A. G.. Universidad de Sevilla; EspañaFil: Arazi, Andres. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carlson, B. V.. Instituto Tecnológico de Aeronáutica; BrasilFil: Chamon, L. C.. Universidade de Sao Paulo; BrasilFil: Fernández García, J. P.. Universidad de Sevilla; EspañaFil: Lépine Szily, A.. Universidade de Sao Paulo; BrasilFil: Lubian, J.. Universidade Federal Fluminense; BrasilFil: Rangel, J.. Universidade Federal Fluminense; BrasilFil: Rodríguez Gallardo, M.. Universidad de Sevilla; EspañaFil: Scarduelli, V.. Universidade de Sao Paulo; BrasilFil: Zagatto, V. A. B.. Universidade Federal Fluminense; Brasi

    Systematic study of optical potential strengths in reactions on Sn 120 involving strongly bound, weakly bound, and exotic nuclei

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    We present new experimental angular distributions for the elastic scattering of Li6+Sn120 at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of He4,6,Li7, Be9,B10, and O16,18 projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding São Paulo potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths.Fil: Alvarez, M. A. G.. Universidad de Sevilla; EspañaFil: Fernández García, J. P.. Universidad de Sevilla; EspañaFil: León García, J. L.. Universidad de Sevilla; EspañaFil: Rodríguez Gallardo, M.. Universidad de Sevilla; EspañaFil: Gasques, L. R.. Universidade de Sao Paulo; BrasilFil: Chamon, L. C.. Universidade de Sao Paulo; BrasilFil: Zagatto, V. A. B.. Universidade de Sao Paulo; BrasilFil: Lépine Szily, A.. Universidade de Sao Paulo; BrasilFil: Oliveira, J. R. B.. Universidade de Sao Paulo; BrasilFil: Scarduelli, V.. Universidade Federal Fluminense; BrasilFil: Carlson, B. V.. Instituto Tecnologico de Aeronautica.; BrasilFil: Casal, J.. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Arazi, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Torres, D. A.. Universidad Nacional de Colombia; ColombiaFil: Ramirez, F.. Universidad Nacional de Colombia; Colombi

    Prevention of congenital malformations and other adverse pregnancy outcomes with 4.0 mg of folic acid : community-based randomized clinical trial in Italy and the Netherlands

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    Background: In 2010 a Cochrane review confirmed that folic acid (FA) supplementation prevents the first- and second-time occurrence of neural tube defects (NTDs). At present some evidence from observational studies supports the hypothesis that FA supplementation can reduce the risk of all congenital malformations (CMs) or the risk of a specific and selected group of them, namely cardiac defects and oral clefts. Furthermore, the effects on the prevention of prematurity, foetal growth retardation and pre-eclampsia are unclear.Although the most common recommendation is to take 0.4 mg/day, the problem of the most appropriate dose of FA is still open.The aim of this project is to assess the effect a higher dose of peri-conceptional FA supplementation on reducing the occurrence of all CMs. Other aims include the promotion of pre-conceptional counselling, comparing rates of selected CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age, abruptio placentae.Methods/Design: This project is a joint effort by research groups in Italy and the Netherlands. Women of childbearing age, who intend to become pregnant within 12 months are eligible for the studies. Women are randomly assigned to receive 4 mg of FA (treatment in study) or 0.4 mg of FA (referent treatment) daily. Information on pregnancy outcomes are derived from women-and-physician information.We foresee to analyze the data considering all the adverse outcomes of pregnancy taken together in a global end point (e.g.: CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age). A total of about 1,000 pregnancies need to be evaluated to detect an absolute reduction of the frequency of 8%. Since the sample size needed for studying outcomes separately is large, this project also promotes an international prospective meta-analysis.Discussion: The rationale of these randomized clinical trials (RCTs) is the hypothesis that a higher intake of FA is related to a higher risk reduction of NTDs, other CMs and other adverse pregnancy outcomes. Our hope is that these trials will act as catalysers, and lead to other large RCTs studying the effects of this supplementation on CMs and other infant and maternal outcomes.Trial registration: Italian trial: ClinicalTrials.gov Identifier: NCT01244347.Dutch trial: Dutch Trial Register ID: NTR3161

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