25 research outputs found

    Investigation of the role of 10^{10}Li resonances in the halo structure of 11^{11}Li through the 11^{11}Li(p, d)10^{10}Li transfer reaction

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    International audienceThe first measurement of the one-neutron transfer reaction 11Li(p,d)10Li performed using the IRIS facility at TRIUMF with a 5.7AMeV11Li beam interacting with a solid H2 target is reported. The 10Li residue was populated strongly as a resonance peak with energy Er=0.62 ±0.04MeV having a total width Γ\Gamma = 0.33 ±0.07MeV. The angular distribution of this resonance is characterized by neutron occupying the 1p1/2orbital. A DWBA analysis yields a spectroscopic factor of 0.67 ±0.12for p1/2 removal strength from the ground state of 11Li to the region of the peak

    Epidemiology and pathogenesis of primary biliary cirrhosis

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    Primary biliary cirrhosis is an autoimmune disease of unknown etiology leading to progressive destruction of small intrahepatic bile ducts and eventually to liver cirrhosis and failure. It is characterized by female predominance (with most cases observed between the ages of 40 and 60) and serum autoantibodies to mitochondrial antigens as highly specific hallmarks. Epidemiologic data indicate a variable incidence and prevalence of the disease. A number of genetic factors have been indicated as playing a role in determining disease susceptibility or progression, although no definitive conclusion has been reached so far. However, as suggested by some epidemiologic observations, a number of environmental factors, including molecular mimicry by either microorganisms or xenobiotics, have also been proposed. A hypothesis gaining support is that environmental factors may trigger disease in genetically predisposed individuals. In this review, the available data regarding the epidemiology and pathogenesis of primary biliary cirrhosis will be described and discussed

    Loss of enterocyte mass is accompanied by diminished turnover of enterocytes after myeloablative therapy in haematopoietic stem-cell transplant recipients.

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    Contains fulltext : 79933.pdf (publisher's version ) (Closed access)BACKGROUND: Intestinal mucosal barrier injury (MBI), resulting from myeloablative conditioning for haematopoietic stem-cell transplantation (HSCT), is an important cause of morbidity. Despite its frequency, recognition presents a challenge, while the aetiology needs still to be unravelled. The relationship between enterocyte mass and enterocyte loss was explored by examining citrulline serum levels and by assessing circulating intestinal fatty acid-binding protein (I-FABP) and ileal bile acid-binding protein (I-BABP), proteins released by dying mature enterocytes. PATIENTS AND METHODS: Thirty-four adult patients with haematological malignancy received allogeneic HSCT (HSCT day 0) 12 days after being given idarubicin, cyclophosphamide and total body irradiation as myeloablative conditioning, a regimen known to induce oral and intestinal MBI. Serum levels of citrulline, I-FABP and I-BABP were measured on HSCT days -12, -6, 0, +7, +14 and +21. Results : Myeloablative conditioning resulted in a significant decrease in serum citrulline with the nadir on HSCT day +7; thereafter, levels rose gradually. Simultaneously, a significant decrease in I-FABP and I-BABP levels occurred from the day of transplant until day +14. CONCLUSIONS: Simultaneous reduction and subsequent increase of citrulline and I-FABP and I-BABP levels following cytotoxic treatment show that enterocyte mass corresponds to lower rate of dying enterocytes, indicating reduced turnover of enterocytes. Assessment of enterocyte turnover and mass offers opportunities for evaluation of new MBI therapies

    The interaction of K--mesons with photographic emulsion nuclei - Part II. The emission of hyperons from K--interactions at rest

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    The emission of Σ-hyperons from 3 037 K- capture stars at rest in nuclear emulsion has been studied. The identification of the hyperons is discussed. Charged Σ-hyperons are emitted from (17.6±1.0)% of all K--stars while (9.6±0.6)% of them lead to the emission of both Σ-hyperons and π-mesons. The Σ-/Σ+ ratio for all stars is 0.86±0.12 while for stars in which a π-meson is also emitted it is 0.45±0.10. The difference between this latter value and the markedly different value (2.0) obtained for K--interactions at rest in a hydrogen bubble chamber is attributed to the Fermi motion of nucleons in the nucleus, and a dependence of the relative K- transition amplitudes on the energy of relative motion of the K--meson and nucleon. The branching ratio, R, of the number of Σ+ decays to π+ and proton respectively is 1.23±0.27. The stable prong distribution of the stars in which a hyperon is emitted, as well as the energy distribution of the Σ-hyperons at emission has been studied. About 16% of all identified charged Σ-hyperons had an emission energy above 60 MeV, and had to be attributed to multi-nucleon interactions of the K--meson. It is estimated that the proportion of all multi-nucleon primary capture prccesses may be as high as (30÷40)%. The interaction of a K--meson with a pair of neutrons seems to occur rarely, if at all. From the fraction of Σ+ emitting stars which also emit a π--meson it is concluded that only about 10% of the π--mesons fail to escape from the nucleus in which capture occurs. This could be understood if K--capture occurs predominantly in the peripheral region of the nucleus. From a similar study of Σ- emitting stars it is found however that the proportion of π+ or π0-mesons, or both, that are absorbed in the nucleus is much higher. Estimates are made of the mean free path in nuclear matter of Σ-hyperons and π0-mesons. Most of the one-nucleon interactions leading to Σ-hyperon production take place with protons and the transition amplitudes corresponding to the T=1 state of isotopic spin is smaller than the T=0 transition amplitude. © 1959 Nicola Zanichelli Editore.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    The interaction and decay of K- mesons in photographic emulsion - Part I. General characteristics of K--Interactions and analysis of events in which a charged π-meson is emitted

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    A total of 3 480 K--mesons has been observed. Of these 445 interact in flight, at a mean energy of 40 MeV and only their general characteristics have been studied. Little difference has been observed between the number of unstable charged particles (Σ±-hypersons and π±-mesons) in these interactions and those in the 3 035 interactions at rest. The 3 035 K--interactions at rest have been studied in detail. In this paper (Part I) are given the results on those interactions in which π-mesons are emitted. An estimate of the Σ-hyperon nuclear potential is based on the energy spectrum of π-mesons emitted in the K--interactions in which the only charged particles emitted are a π-meson and a Σ-hyperon. A detailed examination of the angular distribution of 2-pronged events, and of the sign ratio of the π-mesons, the prong distribution and energy release in all events has led to an estimate of the probabilities of absorption of positive and negative Σ-hyperons in the parent nucleus, and to a partition of the events between the various primary reactions. © 1959 Società Italiana di Fisica.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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