199 research outputs found

    MethCORR modelling of methylomes from formalin-fixed paraffin-embedded tissue enables characterization and prognostication of colorectal cancer

    Get PDF
    Transcriptional characterization and classification has potential to resolve the inter-tumor heterogeneity of colorectal cancer and improve patient management. Yet, robust transcriptional profiling is difficult using formalin-fixed, paraffin-embedded (FFPE) samples, which complicates testing in clinical and archival material. We present MethCORR, an approach that allows uniform molecular characterization and classification of fresh-frozen and FFPE samples. MethCORR identifies genome-wide correlations between RNA expression and DNA methylation in fresh-frozen samples. This information is used to infer gene expression information in FFPE samples from their methylation profiles. MethCORR is here applied to methylation profiles from 877 fresh-frozen/FFPE samples and comparative analysis identifies the same two subtypes in four independent cohorts. Furthermore, subtype-specific prognostic biomarkers that better predicts relapse-free survival (HR = 2.66, 95%CI [1.67-4.22], P value < 0.001 (log-rank test)) than UICC tumor, node, metastasis (TNM) staging and microsatellite instability status are identified and validated using DNA methylation-specific PCR. The MethCORR approach is general, and may be similarly successful for other cancer types

    Equation of state and phonon frequency calculations of diamond at high pressures

    Full text link
    The pressure-volume relationship and the zone-center optical phonon frequency of cubic diamond at pressures up to 600 GPa have been calculated based on Density Functional Theory within the Local Density Approximation and the Generalized Gradient Approximation. Three different approaches, viz. a pseudopotential method applied in the basis of plane waves, an all-electron method relying on Augmented Plane Waves plus Local Orbitals, and an intermediate approach implemented in the basis of Projector Augmented Waves have been used. All these methods and approximations yield consistent results for the pressure derivative of the bulk modulus and the volume dependence of the mode Grueneisen parameter of diamond. The results are at variance with recent precise measurements up to 140 GPa. Possible implications for the experimental pressure determination based on the ruby luminescence method are discussed.Comment: 10 pages, 6 figure

    Modal mineralogy of CI and CI-like chondrites by X-ray diffraction

    Get PDF
    The CI chondrites are some of the most hydrated meteorites available to study, making them ideal samples with which to investigate aqueous processes in the early Solar System. Here, we have used position-sensitive-detector X-ray diffraction (PSD-XRD) to quantify the abundance of minerals in bulk samples of the CI chondrite falls Alais, Orgueil and Ivuna, and the Antarctic CI-like chondrites Y-82162 and Y-980115. We find that Alais, Orgueil and Ivuna are dominated by a mixed serpentine/saponite phyllosilicate (81–84 vol%), plus minor magnetite (6–10%), sulphides (4–7%) and carbonates (<3%). This reflects an extended period of aqueous alteration and the near-complete transformation of anhydrous phases into a secondary mineral assemblage. The similarity in total abundance of phyllosilicate suggests that the CI chondrites all experienced the same degree of aqueous alteration on the parent body. In contrast, Y-82162 contains a highly disordered serpentine/saponite phyllosilicate (68 vol%), sulphide (19%), olivine (11%) and magnetite (2%). This mineralogy is distinct from that of the CI chondrites, attesting to both a different starting mineralogy and alteration history. The structure and relatively low abundance of the phyllosilicate, and the high abundance of olivine, are consistent with previous observations that Y-82162 represents CI-like material that following aqueous alteration suffered thermal metamorphism at temperatures >500 °C. Similarly, Y-980115 contains disordered serpentine/saponite (71 vol%), sulphide (19%), olivine (8%) and magnetite (2%), confirming that it too is a thermally metamorphosed CI-like chondrite. We suggest that the CI-like chondrites are derived from a different parent body than the CI chondrites, which underwent short-lived thermal metamorphism due to impacts and/or solar radiation

    Pulsar-wind nebulae and magnetar outflows: observations at radio, X-ray, and gamma-ray wavelengths

    Get PDF
    We review observations of several classes of neutron-star-powered outflows: pulsar-wind nebulae (PWNe) inside shell supernova remnants (SNRs), PWNe interacting directly with interstellar medium (ISM), and magnetar-powered outflows. We describe radio, X-ray, and gamma-ray observations of PWNe, focusing first on integrated spectral-energy distributions (SEDs) and global spectral properties. High-resolution X-ray imaging of PWNe shows a bewildering array of morphologies, with jets, trails, and other structures. Several of the 23 so far identified magnetars show evidence for continuous or sporadic emission of material, sometimes associated with giant flares, and a few possible "magnetar-wind nebulae" have been recently identified.Comment: 61 pages, 44 figures (reduced in quality for size reasons). Published in Space Science Reviews, "Jets and Winds in Pulsar Wind Nebulae, Gamma-ray Bursts and Blazars: Physics of Extreme Energy Release

    Clonal Hematopoiesis Is Associated with Higher Risk of Stroke

    Get PDF
    Background and Purpose: Clonal hematopoiesis of indeterminate potential (CHIP) is a novel age-related risk factor for cardiovascular disease-related morbidity and mortality. The association of CHIP with risk of incident ischemic stroke was reported previously in an exploratory analysis including a small number of incident stroke cases without replication and lack of stroke subphenotyping. The purpose of this study was to discover whether CHIP is a risk factor for ischemic or hemorrhagic stroke. Methods: We utilized plasma genome sequence data of blood DNA to identify CHIP in 78 752 individuals from 8 prospective cohorts and biobanks. We then assessed the association of CHIP and commonly mutated individual CHIP driver genes (DNMT3A, TET2, and ASXL1) with any stroke, ischemic stroke, and hemorrhagic stroke. Results: CHIP was associated with an increased risk of total stroke (hazard ratio, 1.14 [95% CI, 1.03-1.27]; P=0.01) after adjustment for age, sex, and race. We observed associations with CHIP with risk of hemorrhagic stroke (hazard ratio, 1.24 [95% CI, 1.01-1.51]; P=0.04) and with small vessel ischemic stroke subtypes. In gene-specific association results, TET2 showed the strongest association with total stroke and ischemic stroke, whereas DMNT3A and TET2 were each associated with increased risk of hemorrhagic stroke. Conclusions: CHIP is associated with an increased risk of stroke, particularly with hemorrhagic and small vessel ischemic stroke. Future studies clarifying the relationship between CHIP and subtypes of stroke are needed

    Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

    Search for strong gravity in multijet final states produced in pp collisions at √s=13 TeV using the ATLAS detector at the LHC

    Get PDF
    A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. Limits are also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions
    corecore