6 research outputs found

    Kondo engineering : from single Kondo impurity to the Kondo lattice

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    In the first step, experiments on a single cerium or ytterbium Kondo impurity reveal the importance of the Kondo temperature by comparison to other type of couplings like the hyperfine interaction, the crystal field and the intersite coupling. The extension to a lattice is discussed. Emphasis is given on the fact that the occupation number nfn_f of the trivalent configuration may be the implicit key variable even for the Kondo lattice. Three (P,H,T)(P, H, T) phase diagrams are discussed: CeRu2_2Si2_2, CeRhIn5_5 and SmS

    The density dependence of the transition temperature in a homogenous Bose flui

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    Transition temperature data obtained as a function of particle density in the 4^4He-Vycor system are compared with recent theoretical calculations for 3D Bose condensed systems. In the low density dilute Bose gas regime we find, in agreement with theory, a positive shift in the transition temperature of the form ΔT/T0=γ(na3)1/3\Delta T/T_0 = \gamma(na^{3})^{1/3}. At higher densities a maximum is found in the ratio of Tc/T0T_c /T_0 for a value of the interaction parameter, na3^3, that is in agreement with path-integral Monte Carlo calculations.Comment: 4 pages, 3 figure

    Preparation and enhancement of critical current density in MgB2 wires and tapes

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    We have successfully prepared monofilamentary MgB2 wires and tapes with different sheathed metals such as Cu, Ta/Cu and Fe by the powder-in-tube method. The phase composition, superconducting properties and microstructure features are investigated by x-ray diffractometer, the standard four-probe technique, SQUID magnetometer, SEM and TEM. The results indicate that Jc in MgB2/Ta/Cu wires is higher than 105 A cm−2 at 5 K in 0.1 T and 104 A cm−2 at 20 K in 1 T. By Ti-doping, Jc can be significantly improved. MgB2/Fe wires show very high transport critical current densities of 1.43 × 105 A cm−2 (4.2 K, 4 T), 3.72 × 104 A cm−2 (15 K, 4 T) and 2.34 × 104 A cm−2 (25 K, 3 T). Also the results indicated that small grain size should respond to the large Jc in Ti-doped MgB2 tape and MgB2/Fe wire

    Preparation and enhancement of critical current density in MgB2 wires and tapes

    No full text
    We have successfully prepared monofilamentary MgB2 wires and tapes with different sheathed metals such as Cu, Ta/Cu and Fe by the powder-in-tube method. The phase composition, superconducting properties and microstructure features are investigated by x-ray diffractometer, the standard four-probe technique, SQUID magnetometer, SEM and TEM. The results indicate that Jc in MgB2/Ta/Cu wires is higher than 105 A cm−2 at 5 K in 0.1 T and 104 A cm−2 at 20 K in 1 T. By Ti-doping, Jc can be significantly improved. MgB2/Fe wires show very high transport critical current densities of 1.43 × 105 A cm−2 (4.2 K, 4 T), 3.72 × 104 A cm−2 (15 K, 4 T) and 2.34 × 104 A cm−2 (25 K, 3 T). Also the results indicated that small grain size should respond to the large Jc in Ti-doped MgB2 tape and MgB2/Fe wire

    Rituximab for minimal-change nephrotic syndrome in adulthood: predictive factors for response, long-term outcomes and tolerance

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    BACKGROUND: Minimal-change nephrotic syndrome (MCNS) is a common cause of steroid sensitive nephrotic syndrome (NS) with frequent relapse. Although steroids and calcineurin inhibitors (CNIs) are the cornerstone treatments, the use of rituximab (RTX), a monoclonal antibody targeting B cells, is an efficient and safe alternative in childhood. METHODS: Because data from adults remain sparse, we conducted a large retrospective and multicentric study that included 41 adults with MCNS and receiving RTX. RESULTS: Complete (NS remission and withdrawal of all immunosuppressants) and partial (NS remission and withdrawal of at least one immunosuppressants) clinical responses were obtained for 25 and 7 patients, respectively (overall response 78%), including 3 patients that only received RTX and had a complete clinical response. After a follow-up time of 39 months (6-71), relapses occurred in 18 responder patients [56%, median time 18 months (3-36)]. Seventeen of these received a second course of RTX and then had a complete (n = 13) or partial (n = 4) clinical response. From multivariate analysis, on-going mycophenolate mofetil (MMF) therapy at the time of RTX was the only predictive factor for RTX failure [HR = 0.07 95% CI (0.01-0.04), P = 0.003]. Interestingly, nine patients were still in remission at 14 months (3-36) after B-cell recovery. No significant early or late adverse event occurred after RTX therapy. CONCLUSIONS: RTX is safe and effective in adult patients with MCNS and could be an alternative to steroids or CNIs in patients with a long history of relapsing MCNS
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