On the pooling and subgrouping of data from percutaneous coronary intervention versus coronary artery bypass grafting trials: a call to circumspection

In the modern era, treatment choice is guided by scientific evidence, usually gathered from well-conducted clinical trials, and often followed by the pooling of their data. In this article, we review the most recent pooled evidence regarding myocardial revascularization strategies and discuss how these meta-analyses have inherent shortcomings that should be better understood, prior to their purported conclusions potentially influencing clinical decisions. Properly conducted randomized trials comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) can provide unbiased estimates of treatment effects. However, the design of such trials has often involved a primary outcome that is a composite measure and thus open to challenges with regard to the appropriate interpretation of each individual components. Quantitative synthesis of such data from multiple trials can enable estimates of individual components of the composite outcomes (e.g. all-cause mortality). Where individual patient data are available, a full investigation of mediating effects, or subgroups analyses, may also be undertaken. Relevant to this article, we now have multiple meta-analyses of trials available, which provide an opportunity to assess the appropriateness of criteria for patient selection between PCI and CABG. Consequently, we will appraise the robustness of these meta-analytic methods in answering the question at stake: does PCI provide equivalent results to CABG for the treatment of unprotected left main coronary artery stenosis and multivessel coronary artery disease

Ring closing reaction in diarylethene captured by femtosecond electron crystallography

The photoinduced ring-closing reaction in diarylethene, which serves as a model system for understanding reactive crossings through conical intersections, was directly observed with atomic resolution using femtosecond electron diffraction. Complementary ab initio calculations were also performed. Immediately following photoexcitation, subpicosecond structural changes associated with the formation of an open-ring excited-state intermediate were resolved. The key motion is the rotation of the thiophene rings, which significantly decreases the distance between the reactive carbon atoms prior to ring closing. Subsequently, on the few picosecond time scale, localized torsional motions of the carbon atoms lead to the formation of the closed-ring photoproduct. These direct observations of the molecular motions driving an organic chemical reaction were only made possible through the development of an ultrabright electron source to capture the atomic motions within the limited number of sampling frames and the low data acquisition rate dictated by the intrinsically poor thermal conductivity and limited photoreversibility of organic materials

Human Resource Information Systems in Healthcare: a Systematic Review (Protocol)

Background: Compared with the eHealth literature as a whole, there has been relatively little published research on the use and impacts of Information and Communication Technologies (ICT) designed to support business functions within health organizations. Human Resource Information Systems (HRIS) have the potential to improve organizational efficiency and effectiveness through facilitating workforce planning, financial and operational administration, staff training, and management analytics. However the evidence-base on HRIS in healthcare is widely distributed across disciplinary boundaries and previous reviews have been somewhat limited in scope. This rigorous systematic review will identify, appraise and synthesize existing international research on the implementation and impacts of HRIS in health organizations, in order to provide insights and recommendations that may guide future purchasers, commissioners, implementers, evaluators and users of such systems. Objective: 1. To determine the prevalence and scope of existing research and evaluation pertaining to HRIS in health organisations. 2. To analyse, classify and synthesise existing evidence on the processes and impacts of HRIS development, implementation and adoption. 3. To generate recommendations for HRIS research, practice and policy, with reference to the needs of different stakeholders and communities of practice. Methods: A high level scoping review was first undertaken to inform a draft search strategy, which was refined through several cycles of piloting and iteration in order to optimize its sensitivity and specificity. This is currently being used by the first author, with the help of a medical librarian, to interrogate international electronic databases indexing Medical, Business, ICT and Multi-disciplinary research. Sources of grey literature and reference lists of included studies will also be searched. There will be no restrictions on language or publication year. Two reviewers will screen and code titles and abstracts for potentially eligible studies, for which full text articles will be retrieved. Reasons for exclusion will be noted for the remaining articles. A structured form will be used to summarise and classify the articles. Any disagreements between the reviewers will be resolved through consensus or arbitration by a third reviewer. A PRISMA flow diagram will illustrate the study selection process and ensure transparency of the review. Finally, content experts will be consulted to ensure that important articles have not been missed. Results: A comprehensive search strategy has been piloted and the initial database searches are underway. The review is expected to be complete and published by the end of 2015. Conclusions: By synthesising the existing evidence-base, identifying areas where knowledge is currently lacking and generating recommendations for research and practice, the review will provide a useful resource for decision makers and managers considering or already implementing HRIS, as well as encouraging new research in this area

Stem cell-derived pancreatic Islet encapsulation technologies for immobilized culture and transplantation

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Optical followup of galaxy clusters detected by the South Pole Telescope

The South Pole Telescope (SPT) is a 10 meter telescope operating at mm wavelengths. It has recently completed a three-band survey covering 2500 sq. degrees. One of the survey's main goals is to detect galaxy clusters using Sunyaev-Zeldovich effect and use these clusters for a variety of cosmological and astrophysical studies such as the dark energy equation of state, the primordial non-gaussianity and the evolution of galaxy populations. Since 2005, we have been engaged in a comprehensive optical and near-infrared followup program (at wavelengths between 0.4 and 5 {\mu}m) to image high-significance SPT clusters, to measure their photometric redshifts, and to estimate the contamination rate of the candidate lists. These clusters are then used for various cosmological and astrophysical studies.Comment: For TAUP 2011 proceeding

Cosmological Constraints from Galaxy Clusters in the 2500 square-degree SPT-SZ Survey

(abridged) We present cosmological constraints obtained from galaxy clusters identified by their Sunyaev-Zel'dovich effect signature in the 2500 square degree South Pole Telescope Sunyaev Zel'dovich survey. We consider the 377 cluster candidates identified at z>0.25 with a detection significance greater than five, corresponding to the 95% purity threshold for the survey. We compute constraints on cosmological models using the measured cluster abundance as a function of mass and redshift. We include additional constraints from multi-wavelength observations, including Chandra X-ray data for 82 clusters and a weak lensing-based prior on the normalization of the mass-observable scaling relations. Assuming a LCDM cosmology, where the species-summed neutrino mass has the minimum allowed value (mnu = 0.06 eV) from neutrino oscillation experiments, we combine the cluster data with a prior on H0 and find sigma_8 = 0.797+-0.031 and Omega_m = 0.289+-0.042, with the parameter combination sigma_8(Omega_m/0.27)^0.3 = 0.784+-0.039. These results are in good agreement with constraints from the CMB from SPT, WMAP, and Planck, as well as with constraints from other cluster datasets. Adding mnu as a free parameter, we find mnu = 0.14+-0.08 eV when combining the SPT cluster data with Planck CMB data and BAO data, consistent with the minimum allowed value. Finally, we consider a cosmology where mnu and N_eff are fixed to the LCDM values, but the dark energy equation of state parameter w is free. Using the SPT cluster data in combination with an H0 prior, we measure w = -1.28+-0.31, a constraint consistent with the LCDM cosmological model and derived from the combination of growth of structure and geometry. When combined with primarily geometrical constraints from Planck CMB, H0, BAO and SNe, adding the SPT cluster data improves the w constraint from the geometrical data alone by 14%, to w = -1.023+-0.042