373 research outputs found
Anomalous pressure effect on the magnetic ordering in multiferroic BiMnO3
We report the magnetic field dependent dc magnetization and the
pressure-dependent (pmax ~ 16 kbar) ac susceptibilities Xp(T) on both powder
and bulk multiferroic BiMnO3 samples, synthesized in different batches under
high pressure. A clear ferromagnetic (FM) transition is observed at TC ~ 100 K,
and increases with magnetic field. The magnetic hysteresis behavior is similar
to that of a soft ferromagnet. Ac susceptibility data indicate that both the FM
peak and its temperature (TC) decrease simultaneously with increasing pressure.
Interestingly, above a certain pressure (9 ~ 11 kbar), another peak appears at
Tp ~ 93 K, which also decreases with increasing pressure, with both these peaks
persisting over some intermediate pressure range (9 ~ 13 kbar). The FM peak
disappears with further application of pressure; however, the second peak
survives until present pressure limit (pmax ~ 16 kbar). These features are
considered to originate from the complex interplay of the magnetic and orbital
structure of BiMnO3 being affected by pressure.Comment: 4 pages,4 figures, publised in Physical Review B 78, 092404/200
Incidence and time course of everolimus-related adverse events in postmenopausal women with hormone receptor-positive advanced breast cancer: insights from BOLERO-2.
BackgroundIn the BOLERO-2 trial, everolimus (EVE), an inhibitor of mammalian target of rapamycin, demonstrated significant clinical benefit with an acceptable safety profile when administered with exemestane (EXE) in postmenopausal women with hormone receptor-positive (HR(+)) advanced breast cancer. We report on the incidence, time course, severity, and resolution of treatment-emergent adverse events (AEs) as well as incidence of dose modifications during the extended follow-up of this study.Patients and methodsPatients were randomized (2:1) to receive EVE 10 mg/day or placebo (PBO), with open-label EXE 25 mg/day (n = 724). The primary end point was progression-free survival. Secondary end points included overall survival, objective response rate, and safety. Safety evaluations included recording of AEs, laboratory values, dose interruptions/adjustments, and study drug discontinuations.ResultsThe safety population comprised 720 patients (EVE + EXE, 482; PBO + EXE, 238). The median follow-up was 18 months. Class-effect toxicities, including stomatitis, pneumonitis, and hyperglycemia, were generally of mild or moderate severity and occurred relatively early after treatment initiation (except pneumonitis); incidence tapered off thereafter. EVE dose reduction and interruption (360 and 705 events, respectively) required for AE management were independent of patient age. The median duration of dose interruption was 7 days. Discontinuation of both study drugs because of AEs was higher with EVE + EXE (9%) versus PBO + EXE (3%).ConclusionsMost EVE-associated AEs occur soon after initiation of therapy, are typically of mild or moderate severity, and are generally manageable with dose reduction and interruption. Discontinuation due to toxicity was uncommon. Understanding the time course of class-effect AEs will help inform preventive and monitoring strategies as well as patient education.Trial registration numberNCT00863655
Physical properties and magnetic structure of the intermetallic CeCuBi2 compound
In this work we combine magnetization, pressure dependent electrical resistivity, heat capacity, Cu63 nuclear magnetic resonance (NMR), and x-ray resonant magnetic scattering experiments to investigate the physical properties of the intermetallic CeCuBi2 compound. Our single crystals show an antiferromagnetic ordering at TN≃16 K and the magnetic properties indicate that this compound is an Ising antiferromagnet. In particular, the low temperature magnetization data revealed a spin-flop transition at T=5 K when magnetic fields of about 5.5 T are applied along the c axis. Moreover, the x-ray magnetic diffraction data below TN revealed a commensurate antiferromagnetic structure with propagation wave vector (0012) with the Ce3+ moments oriented along the c axis. Furthermore, our heat capacity, pressure dependent resistivity, and temperature dependent Cu63 NMR data suggest that CeCuBi2 exhibits a weak heavy fermion behavior with strongly localized Ce3+ 4f electrons. We thus discuss a scenario in which both the anisotropic magnetic interactions between the Ce3+ ions and the tetragonal crystalline electric field effects are taking into account in CeCuBi2.Fil: Adriano, C.. Universidade Estadual de Campinas; BrasilFil: Rosa, P.F.S.. Universidade Estadual de Campinas; Brasil. University of California at Irvine; Estados UnidosFil: Jesus, Camilo B. R.. Universidade Estadual de Campinas; BrasilFil: Mardegan, J. R. L.. Universidade Estadual de Campinas; BrasilFil: Garitezi, T. M.. Universidade Estadual de Campinas; BrasilFil: Grant, Taran. California State University; Estados UnidosFil: Fisk, Z.. California State University; Estados UnidosFil: Garcia, Daniel Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Reyes, A. P.. National High Magnetic Field Laboratory; Estados UnidosFil: Kuhns, P. L.. National High Magnetic Field Laboratory; Estados UnidosFil: Urbano, R. R.. Universidade Estadual de Campinas; BrasilFil: Giles, C.. Universidade Estadual de Campinas; BrasilFil: Pagliuso, P. G.. Universidade Estadual de Campinas; Brasi
Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars
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