253 research outputs found

    A Twisted Ladder: relating the Fe superconductors to the high TcT_c cuprates

    Full text link
    We construct a 2-leg ladder model of an Fe-pnictide superconductor and discuss its properties and relationship with the familiar 2-leg cuprate model. Our results suggest that the underlying pairing mechanism for the Fe-pnictide superconductors is similar to that for the cuprates.Comment: 5 pages, 4 figure

    Status of COLDDIAG: A Cold Vacuum Chamber for Diagnostics

    Full text link
    One of the still open issues for the development of superconducting insertion devices is the understanding of the beam heat load. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the beam heat load mechanisms, a cold vacuum chamber for diagnostics is under construction. The following diagnostics will be implemented: i) retarding field analyzers to measure the electron energy and flux, ii) temperature sensors to measure the total heat load, iii) pressure gauges, iv) and mass spectrometers to measure the gas content. The inner vacuum chamber will be removable in order to test different geometries and materials. This will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG will be built to fit in a short straight section at ANKA. A first installation at the synchrotron light source Diamond is foreseen in June 2011. Here we describe the technical design report of this device and the planned measurements with beam.Comment: Presented at First International Particle Accelerator Conference, IPAC'10, Kyoto, Japan, from 23 to 28 May 201

    Changes in Peri-procedural Bleeding Complications Following Percutaneous Coronary Intervention in The United Kingdom Between 2006-2013 (From the British Cardiovascular Interventional Society)

    Get PDF
    Major bleeding is a common complication after percutaneous coronary intervention (PCI), although little is known about how bleeding rates have changed over time and what has driven this. We analyzed all patients who underwent PCI in England and Wales from 2006 to 2013. Multivariate analyses using logistic regression models were performed to identify predictors of bleeding to identify potential factors influencing bleeding trends over time. 545,604 participants who had PCI in England and Wales between 2006 and 2013 were included in the analyses. Overall bleeding rates decreased from 7.0 (CI 6.2 to 7.8) per 1,000 procedures in 2006 to 5.5 (CI 4.7 to 6.2) per 1,000 in 2013. Increasing age, female sex, GPIIb/IIIa inhibitors use, and circulatory support were independently associated with increased risk of bleeding complications whereas radial access and vascular closure device use were independently associated with decreases in risk. Decreases in bleeding rates over time were associated with radial access site, and changes in pharmacology, but this was offset by greater proportion of ACS cases and the adverse patient clinical demographics. In conclusion, major bleeding complications after PCI have decreased due to changes in access site practice and decreased usage of GPIIb/IIIa inhibitors, but this is offset by the increase of patients with higher propensity to bleed. Changes in access site practice nationally have the potential to significantly reduce major bleeding after PCI

    Challenges and opportunities in the design and construction of a GIS-based emission inventory infrastructure for the Niger Delta region of Nigeria

    Get PDF
    © 2017, Springer-Verlag Berlin Heidelberg. Environmental monitoring in middle- and low-income countries is hampered by many factors which include enactment and enforcement of legislations; deficiencies in environmental data reporting and documentation; inconsistent, incomplete and unverifiable data; a lack of access to data; and technical expertise. This paper describes the processes undertaken and the major challenges encountered in the construction of the first Niger Delta Emission Inventory (NDEI) for criteria air pollutants and CO2 released from the anthropogenic activities in the region. This study focused on using publicly available government and research data. The NDEI has been designed to provide a Geographic Information System-based component of an air quality and carbon management framework. The NDEI infrastructure was designed and constructed at 1-, 10- and 20-km grid resolutions for point, line and area sources using industry standard processes and emission factors derived from activities similar to those in the Niger Delta. Due to inadequate, incomplete, potentially inaccurate and unavailable data, the infrastructure was populated with data based on a series of best possible assumptions for key emission sources. This produces outputs with variable levels of certainty, which also highlights the critical challenges in the estimation of emissions from a developing country. However, the infrastructure is functional and has the ability to produce spatially resolved emission estimates

    The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package

    Get PDF
    The Astropy project supports and fosters the development of open-source and openly-developed Python packages that provide commonly-needed functionality to the astronomical community. A key element of the Astropy project is the core package Astropy, which serves as the foundation for more specialized projects and packages. In this article, we provide an overview of the organization of the Astropy project and summarize key features in the core package as of the recent major release, version 2.0. We then describe the project infrastructure designed to facilitate and support development for a broader ecosystem of inter-operable packages. We conclude with a future outlook of planned new features and directions for the broader Astropy project

    Predicting In Vivo Efficacy of Potential Restenosis Therapies by Cell Culture Studies: Species-Dependent Susceptibility of Vascular Smooth Muscle Cells

    Get PDF
    Although drug-eluting stents (DES) are successfully utilized for restenosis therapy, the development of local and systemic therapeutic means including nanoparticles (NP) continues. Lack of correlation between in vitro and in vivo studies is one of the major drawbacks in developing new drug delivery systems. The present study was designed to examine the applicability of the arterial explant outgrowth model, and of smooth muscle cells (SMC) cultures for prescreening of possible drugs. Elucidation of different species sensitivity (rat, rabbit, porcine and human) to diverse drugs (tyrphostins, heparin and bisphsophonates) and a delivery system (nanoparticles) could provide a valuable screening tool for further in vivo studies. The anticipated sensitivity ranking from the explant outgrowth model and SMC mitotic rates (porcine>rat>>rabbit>human) do not correlate with the observed relative sensitivity of those animals to antiproliferative therapy in restenosis models (rat≥rabbit>porcine>human). Similarly, the inhibitory profile of the various antirestenotic drugs in SMC cultures (rabbit>porcine>rat>>human) do not correlate with animal studies, the rabbit- and porcine-derived SMC being highly sensitive. The validity of in vitro culture studies for the screening of controlled release delivery systems such as nanoparticles is limited. It is suggested that prescreening studies of possible drug candidates for restenosis therapy should include both SMC cell cultures of rat and human, appropriately designed with a suitable serum
    • …
    corecore