242 research outputs found

    Superconductivity in the Correlated Pyrochlore Cd_2Re_2O_7

    Full text link
    We report the observation of superconductivity in high-quality Cd2_2Re2_2O7_7 single crystals with room-temperature pyrochlore structure. Resistivity and ac susceptibility measurements establish an onset transition temperature Tconset_c^{onset} = 1.47 K with transition width Δ\DeltaTc_c = 0.25 K. In applied magnetic field, the resistive transition shows a type-II character, with an approximately linear temperature-dependence of the upper critical field Hc2_{c2}. The bulk nature of the superconductivity is confirmed by the specific heat jump with Δ\DeltaC = 37.9 mJ/mol-K. Using the γ\gamma value extracted from normal-state specific heat data, we obtain Δ\DeltaC/γ\gammaTc_c = 1.29, close to the weak coupling BCS value. In the normal state, a negative Hall coefficient below 100 K suggests electron-like conduction in this material. The resistivity exhibits a quadratic T-dependence between 2 and 60 K, i.e., ρ=ρ0\rho =\rho_0+AT2^2, indicative of Fermi-liquid behavior. The values of the Kadowaki-Woods ratio A/γ2\gamma^2 and the Wilson ratio are comparable to that for strongly correlated materials.Comment: 4 pages, 5 figure

    Design and development of the Australian and New Zealand (ANZ) myeloma and related diseases registry

    Get PDF
    © 2016 The Author(s). Background: Plasma cell dyscrasias (PCD) are a spectrum of disorders resulting from the clonal expansion of plasma cells, ranging from the pre-malignant condition monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM). MM generates a significant burden of disease on the community and it is predicted that it will increase in both incidence and prevalence owing to an ageing population and longer survival secondary to new therapeutic options. Robust and comprehensive clinical data are currently lacking but are required to define current diagnostic, investigational and management patterns in Australia and New Zealand (ANZ) for comparison to both local and international guidelines for standards of care. A clinical registry can provide this information and subsequently support development of strategies to address any differences, including providing a platform for clinical trials. The Myeloma and Related Diseases Registry (MRDR) was developed to monitor and explore variations in practices, processes and outcomes in ANZ and provide benchmark outcomes nationally and internationally for PCD. This paper describes the MRDR aims, development and implementation and discusses challenges encountered in the process. Methods: The MRDR was established in 2012 as an online database for a multi-centre collaboration across ANZ, collecting prospective data on patients with a diagnosis of MGUS, MM, solitary plasmacytoma or plasma cell leukaemia. Development of the MRDR required multi-disciplinary team participation, IT and biostatistical support as well as financial resources. Results: More than 1250 patients have been enrolled at 23 sites to date. Here we describe how database development, data entry and securing ethics approval have been major challenges for participating sites and the coordinating centre, and our approaches to resolving them. Now established, the MRDR will provide clinically relevant and credible monitoring, therapy and 'real world' outcome data, to support the conduction of high quality studies. In addition, the Myeloma 1000 sub-study is establishing a repository of paired peripheral blood specimens from registry patients to study mechanisms underlying disease progression. Conclusion: Establishment of the MRDR has been challenging, but it is a valuable investment that will provide a platform for coordinated national and international collaboration for clinical research in PCD in ANZ

    Superconductivity at 1 K in Cd2Re2O7

    Full text link
    We report the first pyrochlore oxide superconductor Cd2Re2O7. Resistivity,magnetic susceptibility,and specific heat measurements on single crystals evidence a bulk superconductivity at 1 K. Another phase transition found at 200 K suggests that a peculiar electronic structure lies behind the superconductivity.Comment: 4 pages, 4 figures, PRL, in pres

    Cluster randomised control trial protocol for estimating the effectiveness and cost-effectiveness of a complex intervention to increase care home staff influenza vaccination rates compared to usual practice (FLUCARE)

    Get PDF
    The care home staff influenza vaccination rate in England is significantly lower than the 75% World Health Organisation recommendation. This represents a substantial potential for resident harm. Barriers to staff vaccination stem from individual and organisational levels. Existing interventions address some but not all barriers and are not underpinned by behavioural science theory. This study aims to estimate the effectiveness and cost-effectiveness of a theory-informed intervention to improve care home staff vaccination rates compared to routine practice. Set in care homes with both nursing and residential focus, and a range of ownership status, only homes providing long stay care to older people with a staff vaccination rate below 40% are eligible to participate. Participation expressions of interest will be sought using a variety of approaches prior to seeking consent. The primary outcome measure is the proportion of staff vaccinated at 6 months, with secondary outcome measures being proportion vaccinated at 3 months, numbers of staff sick days, general practitioner and nurse visits to care home, care home resident hospitalisations and mortality. Based on the assumptions that the mean cluster (care home) size is 54 staff, a coefficient of variation of 0.48, control vaccination rate is 55%, intervention 75%, intra-cluster correlation coefficient of 0.2 and with 90% power, and 20% attrition, we require 39 care homes per arm. Blocked randomisation will be at the level of care home, stratified by the proportion of non-white care home staff, and implemented by Norwich Clinical Trials Unit. The intervention comprises co-designed information videos and posters, provision of in-house staff vaccination clinics, and incentive scheme and monthly data collection on trial outcomes. Beyond usual practice, the control arm will additionally contribute monthly data. Data will be collected at the start, monthly and at 6 months, and analysis will be blind to allocation. Statistical analysis will use the intention-to-treat principle with the difference in vaccination rates between groups compared using a random effect logistic regression model at the staff-level. This will be the first study to use a theory-informed intervention designed to comprehensively address identified barriers to care home staff influenza vaccination

    Coexistence of metallic and nonmetallic properties in the pyrochlore Lu2Rh2O7

    Get PDF
    Transition metal oxides of the 4d4d and 5d5d block have recently become the targets of materials discovery, largely due to their strong spin-orbit coupling that can generate exotic magnetic and electronic states. Here we report the high pressure synthesis of Lu2_2Rh2_2O7_7, a new cubic pyrochlore oxide based on 4d54d^5 Rh4+^{4+} and characterizations via thermodynamic, electrical transport, and muon spin relaxation measurements. Magnetic susceptibility measurements reveal a large temperature-independent Pauli paramagnetic contribution, while heat capacity shows an enhanced Sommerfeld coefficient, γ\gamma = 21.8(1) mJ/mol-Rh K2^2. Muon spin relaxation measurements confirm that Lu2_2Rh2_2O7_7 remains paramagnetic down to 2 K. Taken in combination, these three measurements suggest that Lu2_2Rh2_2O7_7 is a correlated paramagnetic metal with a Wilson ratio of RW=2.5R_W = 2.5. However, electric transport measurements present a striking contradiction as the resistivity of Lu2_2Rh2_2O7_7 is observed to monotonically increase with decreasing temperature, indicative of a nonmetallic state. Furthermore, although the magnitude of the resistivity is that of a semiconductor, the temperature dependence does not obey any conventional form. Thus, we propose that Lu2_2Rh2_2O7_7 may belong to the same novel class of non-Fermi liquids as the nonmetallic metal FeCrAs.Comment: 11 pages, 5 figure

    Carfilzomib and dexamethasone versus bortezomib and dexamethasone for patients with relapsed or refractory multiple myeloma (ENDEAVOR): And randomised, phase 3, open-label, multicentre study

    Get PDF
    Background: Bortezomib with dexamethasone is a standard treatment option for relapsed or refractory multiple myeloma. Carfilzomib with dexamethasone has shown promising activity in patients in this disease setting. The aim of this study was to compare the combination of carfilzomib and dexamethasone with bortezomib and dexamethasone in patients with relapsed or refractory multiple myeloma. Methods: In this randomised, phase 3, open-label, multicentre study, patients with relapsed or refractory multiple myeloma who had one to three previous treatments were randomly assigned (1:1) using a blocked randomisation scheme (block size of four) to receive carfilzomib with dexamethasone (carfilzomib group) or bortezomib with dexamethasone (bortezomib group). Randomisation was stratified by previous proteasome inhibitor therapy, previous lines of treatment, International Staging System stage, and planned route of bortezomib administration if randomly assigned to bortezomib with dexamethasone. Patients received treatment until progression with carfilzomib (20 mg/m2 on days 1 and 2 of cycle 1; 56 mg/m2 thereafter; 30 min intravenous infusion) and dexamethasone (20 mg oral or intravenous infusion) or bortezomib (1·3 mg/m2; intravenous bolus or subcutaneous injection) and dexamethasone (20 mg oral or intravenous infusion). The primary endpoint was progression-free survival in the intention-to-treat population. All participants who received at least one dose of study drug were included in the safety analyses. The study is ongoing but not enrolling participants; results for the interim analysis of the primary endpoint are presented. The trial is registered at ClinicalTrials.gov, number NCT01568866. Findings: Between June 20, 2012, and June 30, 2014, 929 patients were randomly assigned (464 to the carfilzomib group; 465 to the bortezomib group). Median follow-up was 11·9 months (IQR 9·3-16·1) in the carfilzomib group and 11·1 months (8·2-14·3) in the bortezomib group. Median progression-free survival was 18·7 months (95% CI 15·6-not estimable) in the carfilzomib group versus 9·4 months (8·4-10·4) in the bortezomib group at a preplanned interim analysis (hazard ratio [HR] 0·53 [95% CI 0·44-0·65]; p<0·0001). On-study death due to adverse events occurred in 18 (4%) of 464 patients in the carfilzomib group and in 16 (3%) of 465 patients in the bortezomib group. Serious adverse events were reported in 224 (48%) of 463 patients in the carfilzomib group and in 162 (36%) of 456 patients in the bortezomib group. The most frequent grade 3 or higher adverse events were anaemia (67 [14%] of 463 patients in the carfilzomib group vs 45 [10%] of 456 patients in the bortezomib group), hypertension (41 [9%] vs 12 [3%]), thrombocytopenia (39 [8%] vs 43 [9%]), and pneumonia (32 [7%] vs 36 [8%]). Interpretation: For patients with relapsed or refractory multiple myeloma, carfilzomib with dexamethasone could be considered in cases in which bortezomib with dexamethasone is a potential treatment option. Funding: Onyx Pharmaceuticals, Inc., an Amgen subsidiary

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

    Get PDF
    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio
    corecore