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Abstract: Rapidly solidified LaNi4.25Al0.75 alloy was prepared by melt spinning and its hydrogen storage properties were examined. The hydrogen storage capacities and the equilibrium pressures of the unannealed melt-spun (UMS) LaNi4.25Al0.75 alloy were found to be nearly identical to those of the annealed induction-melt (AIM) alloy. However, the resistance to pulverization was greatly improved and the hysteresis was markedly decreased for the UMS alloy, while its activation became rather difficult. [Copyright &y& Elsevier]

Abstract: Multiferroic Bi0.95Sm0.05Fe1−x Co x O3 (x=0−0.1) ceramics were prepared by the rapid liquid phase sintering method. For all the samples studied, the dielectric constant and dielectric loss decrease with increasing frequency in the range from 1kHz to 1MHz. It shows that the dielectric constant of Bi0.95Sm0.05FeO3 at 10kHz is about forty times larger than that of pure BiFeO3. This dramatic change in the dielectric properties of Bi0.95Sm0.05Fe1−x Co x O3 (x=0−0.1) samples can be understood in terms of the space charge limited conduction associated with crystal defects, which was indicated by the increase of magnetoelectric effect with doping Co3+ under applied magnetic field from 1 to 8kOe. It was believed that the ferroelectric polarization enhancement comes from the exchange interaction between the Sm3+ and Fe3+ or Co3+ ions for Bi0.95Sm0.05Fe0.95Co0.05O3 at room temperature. [Copyright &y& Elsevier]

Abstract: Carbon thin films have been prepared on Si by plasma-based ion implantation (PBII) with H2 and C2H2 mixed gases with various H2/C2H2 ratios. The effect of the H2/C2H2 ratio on the structure and tribological properties of the thin films has been investigated. XPS composition depth profile shows that a H2/C2H2 ratio of about 1.0 corresponds to the just appearance of a carbon film growing on a C–Si transition layer showing gradually compositional and structural changes between the carbon film and the substrate, and above the ratio of 1.0 corresponds to no carbon film but a carbon-implanted layer. As the H2/C2H2 ratio increases, the carbon film shows the rapidly decreasing thickness. Raman spectra show that the carbon films are diamond-like carbon (DLC) films rich in Sp3 bonds carbons. A H2/C2H2 ratio of approximately 0.1 corresponds to the maximal Sp3/Sp2 ratio. The H2/C2H2 ratio in the range of 0–0.3 corresponds to larger Sp3/Sp2 ratio than the ratio of 0 (without H2 additive). AFM morphologies exhibit that the DLC films are smooth and compact, and the H2/C2H2 ratio of 0.08 corresponds to the smallest roughness. On the other hand, ball-on-disk sliding wear experiments show that the H2/C2H2 ratio of 0–0.15 exhibit more significant improvement in tribological properties of the DLC films than the ratio of 0. In particular, at low sliding load of below 0.5 N the DLC films present more than 3 h-wear life and near to zero-wear rate. It is found that the H2/C2H2 ratio of about 0.08 corresponds to the best tribological properties. The influences of sliding load, sliding frequency, film thickness and counter-ball materials on the tribological properties are also presented. [Copyright &y& Elsevier]

Background: Previous studies have suggested that a single dose of rifampin has protective effects against leprosy in close contacts of patients with the disease. Rifapentine was shown to have greater bactericidal activity against Mycobacterium leprae than rifampin in murine models of leprosy, but data regarding its effectiveness in preventing leprosy are lacking., Methods: We conducted a cluster-randomized, controlled trial to investigate whether single-dose rifapentine is effective in preventing leprosy in household contacts of patients with leprosy. The clusters (counties or districts in Southwest China) were assigned to one of three trial groups: single-dose rifapentine, single-dose rifampin, or control (no intervention). The primary outcome was the 4-year cumulative incidence of leprosy among household contacts., Results: A total of 207 clusters comprising 7450 household contacts underwent randomization; 68 clusters (2331 household contacts) were assigned to the rifapentine group, 71 (2760) to the rifampin group, and 68 (2359) to the control group. A total of 24 new cases of leprosy occurred over the 4-year follow-up, for a cumulative incidence of 0.09% (95% confidence interval [CI], 0.02 to 0.34) with rifapentine (2 cases), 0.33% (95% CI, 0.17 to 0.63) with rifampin (9 cases), and 0.55% (95% CI, 0.32 to 0.95) with no intervention (13 cases). In an intention-to-treat analysis, the cumulative incidence in the rifapentine group was 84% lower than that in the control group (cumulative incidence ratio, 0.16; multiplicity-adjusted 95% CI, 0.03 to 0.87; P = 0.02); the cumulative incidence did not differ significantly between the rifampin group and the control group (cumulative incidence ratio, 0.59; multiplicity-adjusted 95% CI, 0.22 to 1.57; P = 0.23). In a per-protocol analysis, the cumulative incidence was 0.05% with rifapentine, 0.19% with rifampin, and 0.63% with no intervention. No severe adverse events were observed., Conclusions: The incidence of leprosy among household contacts over 4 years was lower with single-dose rifapentine than with no intervention. (Funded by the Ministry of Health of China and the Chinese Academy of Medical Sciences; Chinese Clinical Trial Registry number, ChiCTR-IPR-15007075.)., (Copyright © 2023 Massachusetts Medical Society.)