115 research outputs found

    Breast cancer in previously thyroidectomized patients: which thyroid disorders are a risk factor?

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    The aim of this study was to evaluate whether there are thyroid diseases in which breast cancer will appear later as well as the role of autoimmunity. This was a retrospective observational study. A total of 410 females (thyroid surgery and later breast cancer) and 524 females (thyroid surgery only) were compared with regard to pathological thyroid findings, thyroid hormones, thyroid autoimmunity and type of breast cancer. Thyroid autoimmunity, especially antithyroid peroxidase antibodies, significantly increased the risk of breast cancer (p < 0.01); however, this was not true for other thyroid diseases, including thyroid cancer. No variant of breast cancer was predominant, and only thyroid autoimmunity was associated with the risk of breast cancer. Further research is needed to explain the impacts of different antithyroid antibodies.Lay abstract: Several studies have long hypothesized a link between thyroid disease and breast cancer. The authors' study retrospectively examined a large cohort of patients who initially underwent thyroid surgery and subsequently had breast cancer compared with a control group consisting of patients with only breast cancer. This comparison showed that only autoimmune thyroid disease was a risk factor for subsequent breast cancer, whereas no significant association of thyroid cancer with breast cancer was found

    Uncommon localizations of hydatid cyst. Review of the literature

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    Introduction. Hydatid disease is an endemic anthropozoonosis with usual localization in liver and lungs. Rarely it localizes in uncommon sites as spleen, skeleton, kidney, brain, cardiac muscle, peritoneum, sub cutis. Complications of uncommon localizations are the same that for usual ones. Material and methods. Review of the literature on rare and atypical localization of hydatid cysts in soft tissues. Key-words used on Pub-Med [(echinococ OR hydatid) AND (soft tissue OR subcutaneous OR cutaneous)] without time limit. There were found 282 articles; 242 were excluded because of muscular or bone localizations. 40 were coherent. Results. Different variables are taken into account: age, sex, geographic area, anatomic localization of the cyst, dimension, symptoms, signs, mobility, blood exams and specific serological tests, imaging techniques for diagnosis, existing of septa in the structure, treatment, anaesthesia, spillage, neo-adjuvant and adjuvant treatment, follow-up period, recurrent lesions. Conclusion. It would be useful create an homogeneous and standardized collection of data of these rare and potentially life-threatening conditions in order to create guide-line of diagnostic and therapeutic process and create (or adopt) unique classification of the lesions

    Measurement of the branching ratio for beta-delayed alpha decay of 16N

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    While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics, the cross section at energies relevant to hydrostatic helium burning is too small to be directly measured in the laboratory. The beta-delayed alpha spectrum of 16N can be used to constrain the extrapolation of the E1 component of the S-factor; however, with this approach the resulting S-factor becomes strongly correlated with the assumed beta-alpha branching ratio. We have remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented Si detector and counting the number of beta-alpha decays relative to the number of implantations. Our result, 1.49(5)e-5, represents a 24% increase compared to the accepted value and implies an increase of 14% in the extrapolated S-factor

    Measuring total reaction cross-sections at energies near the coulomb barrier by the active target method

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    An experimental technique is described that is able to measure reaction cross-sections at energies around the Coulomb barrier by using low intensity beams and a Si detector as an active target. Set-up optimization was carefully investigated in terms of collimation, detector efficiency and pile-up rejection. The method has been tested by measuring the total reaction cross-section sigma(R)(E) for the (7)Li + (28)Si system in the energy range of E(lab) = 12-16 MeV. The deduced excitation function sigma(R)(E) agrees with the data obtained in a previous experiment. The presented technique can also be applied in order to determine total reaction cross-sections for low intensity radioactive beams at energies around the Coulomb barrier. (C) 2009 Elsevier B.V. All rights reserved. Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipmen

    Structure of 13^{13}Be probed via secondary beam reactions

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    The low-lying level structure of the unbound neutron-rich nucleus 13^{13}Be has been investigated via breakup on a carbon target of secondary beams of 14,15^{14,15}B at 35 MeV/nucleon. The coincident detection of the beam velocity 12^{12}Be fragments and neutrons permitted the invariant mass of the 12^{12}Be+nn and 12^{12}Be+nn+nn systems to be reconstructed. In the case of the breakup of 15^{15}B, a very narrow structure at threshold was observed in the 12^{12}Be+nn channel. Contrary to earlier stable beam fragmentation studies which identified this as a strongly interacting ss-wave virtual state in 13^{13}Be, analysis here of the 12^{12}Be+nn+nn events demonstrated that this was an artifact resulting from the sequential-decay of the 14^{14}Be(2+^+) state. Single-proton removal from 14^{14}B was found to populate a broad low-lying structure some 0.70 MeV above the neutron-decay threshold in addition to a less prominent feature at around 2.4 MeV. Based on the selectivity of the reaction and a comparison with (0-3)ω\hbar\omega shell-model calculations, the low-lying structure is concluded to most probably arise from closely spaced Jπ^\pi=1/2+^+ and 5/2+^+ resonances (Er_r=0.40±\pm0.03 and 0.850.11+0.15^{+0.15}_{-0.11} MeV), whilst the broad higher-lying feature is a second 5/2+^+ level (Er_r=2.35±\pm0.14 MeV). Taken in conjunction with earlier studies, it would appear that the lowest 1/2+^+ and 1/2^- levels lie relatively close together below 1 MeV.Comment: 14 pages, 13 figures, 2 tables. Accepted for publication in Physical Review

    Heavy residue excitation functions for the collisions 6, 7Li + 64Zn near the Coulomb barrier

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    Excitation functions for the production of heavy residues have been measured for the collisions 6, 7Li+64Zn at energies around and below the Coulomb barrier. The cross sections for heavy residue production have been measured using an activation technique, detecting off-line the characteristic atomic x-rays emitted in the electron capture decay of the reaction products. The experimental relative yields of the residues have been compared with statistical model calculations performed by using the code cascade. Such a comparison suggests that heavy residue production is dominated by complete fusion at above-barrier energies, whereas different processes like incomplete fusion and/or transfer become dominant in the sub-barrier energy region. The heavy residue excitation function ratio between the 6Li- and 7Li-induced collisions shows an increasing trend as the energy decreases below the barrier

    Experimental study of the collision 11Be + 64Zn around the Coulomb barrier

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    In this paper details of the experimental procedure and data analysis of the collision of 11Be+64Zn around the Coulomb barrier are described and discussed in the framework of different theoretical approaches. In a previous work [ A. Di Pietro et al. Phys. Rev. Lett. 105 022701 (2010)], the elastic scattering angular distribution of the collisions 9, 10Be+64Zn as well as the angular distribution for the quasielastic scattering and transfer/breakup cross sections for the 11Be+64Zn reaction were briefly reported. The suppression of the quasielastic angular distribution in the Coulomb-nuclear interference angular region observed in the collision of the 11Be halo nucleus with respect to the other two beryllium isotopes was interpreted as being caused by a long-range absorption owing to the long decay length of the 11Be wave function. In this paper, new continuum-discretized coupled-channel calculations of the 11Be+64Zn reaction are reported in the attempt to interpret the effect of coupling with the breakup channels on the measured cross sections. The calculations show that the observed suppression of the Coulomb-nuclear interference peak is caused by a combined effect of Coulomb and nuclear couplings to the breakup channels

    Evidence of strong effects of the 11Be halo structure on reaction processes at energies around the Coulomb barrier

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    The collision induced by the three Beryllium isotopes, 9, 10, 11Be, on 64Zn target were investigated at Ec.m. ≈ 1.4 the Coulomb barrier. Elastic scattering angular distributions were measured for the 9, 10Be collisions whereas, in the 11Be case the quasielastic scattering angular distribution was obtained. A strong damping of the quasielastic cross-section was observed in the 11Be case, especially in the angular range around the Coulomb-nuclear interference peak. In this latter case a large total-reaction cross-section is found, more than a factor of two larger than the ones extracted in the reactions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the 11Be case could be attributed to transfer and/or break-up events

    Elastic Scattering and Reaction Mechanisms of the Halo Nucleus 11Be around the Coulomb Barrier

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    Collisions induced by 9, 10, 11Be on a 64Zn target at the same c.m. energy were studied. For the first time, strong effects of the 11Be halo structure on elastic-scattering and reaction mechanisms at energies near the Coulomb barrier are evidenced experimentally. The elastic-scattering cross section of the 11Be halo nucleus shows unusual behavior in the Coulomb-nuclear interference peak angular region. The extracted total-reaction cross section for the 11Be collision is more than double the ones measured in the collisions induced by 9, 10Be. It is shown that such a strong enhancement of the total-reaction cross section with 11Be is due to transfer and breakup processes

    Elastic scattering and heavy residue production in the collisions 6,7Li+64 Zn around the Coulomb barrier

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    Elastic scattering angular distributions and heavy residue production cross sections have been measured at different energies around the Coulomb barrier for the systems 6,7 Li+ 64 Zn. Optical model fits of the elastic angular distributions were performed using a renormalized double folding potential and absence of usual threshold anomaly in the optical potential was found. Excitation functions for heavy residue production have been measured using an activation technique. Comparison of the data with the results of different calculations show that complete fusion is the dominant reaction mechanism above the barrier, whereas the heavy residue yield below the barrier is mainly due to incomplete fusion and transfer
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