143 research outputs found

    An ongoing case-control study to evaluate the NHS Bowel Cancer Screening Programme

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    © 2014 Massat et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    Spin-echo and quantum versus classical critical fluctuations in TmVO4_4

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    Using spin-echo Nuclear Magnetic Resonance in the model Transverse-Field Ising system TmVO4_4, we show that low frequency quantum fluctuations at the quantum critical point have a very different effect on 51^{51}V nuclear-spins than classical low-frequency noise or fluctuations that arise at a finite temperature critical point. Spin-echos filter out the low frequency classical noise but not the quantum fluctuations. This allows us to directly visualize the quantum critical fan and demonstrate the persistence of quantum fluctuations at the critical coupling strength in TmVO4_4 to high temperatures in an experiment that remains transparent to finite temperature classical phase transitions. These results show that while dynamical decoupling schemes can be quite effective in eliminating classical noise in a qubit, a quantum critical environment may lead to rapid entanglement and decoherence.Comment: 10 pages, 5 figure

    Second order Zeeman interaction and ferroquadrupolar order in TmVO4_4

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    TmVO4_{4} exhibits ferroquadrupolar order of the Tm 4f electronic orbitals at low temperatures, and is a model system for Ising nematicity that can be tuned continuously to a quantum phase transition via magnetic fields along the cc-axis. Here we present 51^{51}V nuclear magnetic resonance data in magnetic fields perpendicular to the cc-axis in a single crystal that has been carefully cut by a plasma focused ion beam to an ellipsoidal shape to minimize the inhomogeneity of the internal demagnetization field. The resulting dramatic increase in spectral resolution enabled us to resolve the anisotropy of the electric field gradient and to measure the magnetic and quadrupolar relaxation channels separately. Perpendicular magnetic fields nominally do not couple to the low energy degrees of freedom, but we find a significant nonlinear contribution for sufficiently large fields that give rise to a rich phase diagram. The in-plane magnetic field can act either as an effective transverse or longitudinal field to the Ising nematic order, depending on the orientation relative to the principle axes of the quadrupole order, and leads to a marked in-plane anisotropy in both relaxation channels. We find that the small in-plane transverse fields initially enhance the ferroquadrupolar ordering temperature but eventually suppress the long-range order. We tentatively ascribe this behavior to the competing effects of field-induced mixing of higher energy crystal field states and the destabilizing effects of field-induced quantum fluctuations.Comment: 15 pages, 13 figure

    Lattice-shifted nematic quantum critical point in FeSe1xSxFeSe_{1−x}S_{x}

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    We report the evolution of nematic fluctuations in FeSe1xSxFeSe_{1−x}S_{x} single crystals as a function of Sulfur content x across the nematic quantum critical point (QCP) xcx_{c} ~ 0.17 via Raman scattering. The Raman spectra in the B1gB_{1g} nematic channel consist of two components, but only the low energy one displays clear fingerprints of critical behavior and is attributed to itinerant carriers. Curie–Weiss analysis of the associated nematic susceptibility indicates a substantial effect of nemato-elastic coupling, which shifts the location of the nematic QCP. We argue that this lattice-induced shift likely explains the absence of any enhancement of the superconducting transition temperature at the QCP. The presence of two components in the nematic fluctuations spectrum is attributed to the dual aspect of electronic degrees of freedom in Hund’s metals, with both itinerant carriers and local moments contributing to the nematic susceptibility

    Lattice-Shifted Nematic Quantum Critical Point in FeSe1x_{1-x}Sx_x

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    We report the evolution of nematic fluctuations in FeSe1x_{1-x}Sx_x single crystals as a function of Sulfur content xx across the nematic quantum critical point (QCP) xcx_c\sim 0.17 via Raman scattering. The Raman spectra in the B1gB_{1g} nematic channel consist of two components, but only the low energy one displays clear fingerprints of critical behavior and is attributed to itinerant carriers. Curie-Weiss analysis of the associated nematic susceptibility indicates a substantial effect of nemato-elastic coupling which shifts the location of the nematic QCP. We argue that this lattice-induced shift likely explains the absence of any enhancement of the superconducting transition temperature at the QCP. The presence of two components in the nematic fluctuations spectrum is attributed to the dual aspect of electronic degrees of freedom in Hund's metals, with both itinerant carriers and local moments contributing to the nematic susceptibility.Comment: 10 pages, 5 figure

    Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

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    Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

    Evaluation of a service intervention to improve awareness and uptake of bowel cancer screening in ethnically-diverse areas

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    The Policy Research Unit in Cancer Awareness, Screening and Early Diagnosis receives funding for a research programme from the UK Department of Health Policy Research Programme (grant no. 106/0001). It is a collaboration between researchers from seven institutions (the Queen Mary University of London, the UCL, the King’s College London, the London School of Hygiene and Tropical Medicine, the Hull York Medical School, the Durham University and the Peninsula Medical School)

    Modular hybrid total hip arthroplasty. Experimental study in dogs

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    Background: This prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs.Methods: Ten skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation.Results: Excellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis.Conclusions: The canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb

    Quantitative trait locus analysis identifies Gabra3 as a regulator of behavioral despair in mice

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    The Tail Suspension Test (TST), which measures behavioral despair, is widely used as an animal model of human depressive disorders and antidepressant efficacy. In order to identify novel genes involved in the regulation of TST performance, we crossed an inbred strain exhibiting low immobility in the TST (RIIIS/J) with two high-immobility strains (C57BL/6J and NZB/BlNJ) to create two distinct F2 hybrid populations. All F2 offspring (n = 655) were genotyped at high density with a panel of SNP markers. Whole-genome interval mapping of the F2 populations identified statistically significant quantitative trait loci (QTLs) on mouse chromosomes (MMU) 4, 6, and X. Microarray analysis of hippocampal gene expression in the three parental strains was used to identify potential candidate genes within the MMUX QTLs identified in the NZB/BlNJ × RIIIS/J cross. Expression of Gabra3, which encodes the GABAA receptor α3 subunit, was robust in the hippocampus of B6 and RIIIS mice but absent from NZB hippocampal tissue. To verify the role of Gabra3 in regulating TST behavior in vivo, mice were treated with SB-205384, a positive modulator of the α3 subunit. SB-205384 significantly reduced TST immobility in B6 mice without affecting general activity, but it had no effect on behavior in NZB mice. This work suggests that GABRA3 regulates a behavioral endophenotype of depression and establishes this gene as a viable new target for the study and treatment of human depression
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