715 research outputs found

    Coexisting multiple order parameters in single-layer LuMnO3 films

    Get PDF
    Magnetoelectric multiferroics hold great promise for electrical control of magnetism or magnetic control of ferroelectricity. However, single phase ferroelectric materials with a sizeable ferromagnetic magnetization are rare. Here, we demonstrate that a single- phase orthorhombic LuMnO3 thin film features coexisting magnetic and ferroelectric orders. The temperature dependence of the different order parameters are presented with ferromagnetic order appearing below 100 K and thus at much higher temperatures than ferroelectricity or antiferromagnetism (TN,TFE≤40K)

    Tuning the multiferroic mechanisms of TbMnO3 by epitaxial strain

    Full text link
    A current challenge in the field of magnetoelectric multiferroics is to identify systems that allow a controlled tuning of states displaying distinct magnetoelectric responses. Here we show that the multiferroic ground state of the archetypal multiferroic TbMnO3 is dramatically modified by epitaxial strain. Neutron diffraction reveals that in highly strained films the magnetic order changes from the bulk-like incommensurate bc-cycloidal structure to commensurate magnetic order. Concomitant with the modification of the magnetic ground state, optical second-harmonic generation (SHG) and electric measurements show an enormous increase of the ferroelectric polarization, and a change in its direction from along the c- to the a-axis. Our results suggest that the drastic change of multiferroic properties results from a switch of the spin-current magnetoelectric coupling in bulk TbMnO3 to symmetric magnetostriction in epitaxially-strained TbMnO3. These findings experimentally demonstrate that epitaxial strain can be used to control single-phase spin-driven multiferroic states

    Different strategies for using topical corticosteroids in people with eczema

    Get PDF
    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To establish the effectiveness and safety of different ways of using topical corticosteroids in people with eczema

    Investigating the Genetic Diversity of H5 Avian Influenza Viruses in the United Kingdom from 2020–2022

    Get PDF
    Publication history: Accepted - 27 April 2023; Published - 26 June 2023.Since 2020, the United Kingdom and Europe have experienced annual epizootics of high-pathogenicity avian influenza virus (HPAIV). The first epizootic, during the autumn/winter of 2020–2021, involved six H5Nx subtypes, although H5N8 HPAIV dominated in the United Kingdom. While genetic assessments of the H5N8 HPAIVs within the United Kingdom demonstrated relative homogeneity, there was a background of other genotypes circulating at a lower degree with different neuraminidase and internal genes. Following a small number of detections of H5N1 in wild birds over the summer of 2021, the autumn/winter of 2021–2022 saw another European H5 HPAIV epizootic that dwarfed the prior epizootic. This second epizootic was dominated almost exclusively by H5N1 HPAIV, although six distinct genotypes were defined. We have used genetic analysis to evaluate the emergence of different genotypes and proposed reassortment events that have been observed. The existing data suggest that the H5N1 viruses circulating in Europe during late 2020 continued to circulate in wild birds throughout 2021, with minimal adaptation, but then went on to reassort with AIVs in the wild bird population. We have undertaken an in-depth genetic assessment of H5 HPAIVs detected in the United Kingdom over two winter seasons and demonstrate the utility of in-depth genetic analyses in defining the diversity of H5 HPAIVs circulating in avian species, the potential for zoonotic risk, and whether incidents of lateral spread can be defined over independent incursions of infections from wild birds. This provides key supporting data for mitigation activities.This work was funded by the Department for Environment, Food, and Rural Affairs (Defra) (United Kingdom) and the Devolved Administrations of Scotland and Wales through the following programs of work: SV3400, SV3032, SV3006, and SE2213. Funding for diagnostic testing in Northern Ireland was provided by the Department for Agriculture, Environment, and Rural Affairs (DAERA). The writing and data analysis for the manuscript were also supported in part by the DELTA-FLU project funded by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 727922. A.C.B., J.J., and I.H.B. were also partly funded by the BBSRC/Defra-funded research initiative FluMAP (BB/X006204/1)

    Strategies for using topical corticosteroids in children and adults with eczema.

    Get PDF
    BACKGROUND: Eczema is a common skin condition. Although topical corticosteroids have been a first-line treatment for eczema for decades, there are uncertainties over their optimal use. OBJECTIVES: To establish the effectiveness and safety of different ways of using topical corticosteroids for treating eczema. SEARCH METHODS: We searched databases to January 2021 (Cochrane Skin Specialised Register; CENTRAL; MEDLINE; Embase; GREAT) and five clinical trials registers. We checked bibliographies from included trials to identify further trials. SELECTION CRITERIA: Randomised controlled trials in adults and children with eczema that compared at least two strategies of topical corticosteroid use. We excluded placebo comparisons, other than for trials that evaluated proactive versus reactive treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods, with GRADE certainty of evidence for key findings. Primary outcomes were changes in clinician-reported signs and relevant local adverse events. Secondary outcomes were patient-reported symptoms and relevant systemic adverse events. For local adverse events, we prioritised abnormal skin thinning as a key area of concern for healthcare professionals and patients. MAIN RESULTS: We included 104 trials (8443 participants). Most trials were conducted in high-income countries (81/104), most likely in outpatient or other hospital settings. We judged only one trial to be low risk of bias across all domains. Fifty-five trials had high risk of bias in at least one domain, mostly due to lack of blinding or missing outcome data. Stronger-potency versus weaker-potency topical corticosteroids Sixty-three trials compared different potencies of topical corticosteroids: 12 moderate versus mild, 22 potent versus mild, 25 potent versus moderate, and 6 very potent versus potent. Trials were usually in children with moderate or severe eczema, where specified, lasting one to five weeks. The most reported outcome was Investigator Global Assessment (IGA) of clinician-reported signs of eczema. We pooled four trials that compared moderate- versus mild-potency topical corticosteroids (420 participants). Moderate-potency topical corticosteroids probably result in more participants achieving treatment success, defined as cleared or marked improvement on IGA (52% versus 34%; odds ratio (OR) 2.07, 95% confidence interval (CI) 1.41 to 3.04; moderate-certainty evidence). We pooled nine trials that compared potent versus mild-potency topical corticosteroids (392 participants). Potent topical corticosteroids probably result in a large increase in number achieving treatment success (70% versus 39%; OR 3.71, 95% CI 2.04 to 6.72; moderate-certainty evidence). We pooled 15 trials that compared potent versus moderate-potency topical corticosteroids (1053 participants). There was insufficient evidence of a benefit of potent topical corticosteroids compared to moderate topical corticosteroids (OR 1.33, 95% CI 0.93 to 1.89; moderate-certainty evidence). We pooled three trials that compared very potent versus potent topical corticosteroids (216 participants). The evidence is uncertain with a wide confidence interval (OR 0.53, 95% CI 0.13 to 2.09; low-certainty evidence). Twice daily or more versus once daily application We pooled 15 of 25 trials in this comparison (1821 participants, all reported IGA). The trials usually assessed adults and children with moderate or severe eczema, where specified, using potent topical corticosteroids, lasting two to six weeks. Applying potent topical corticosteroids only once a day probably does not decrease the number achieving treatment success compared to twice daily application (OR 0.97, 95% CI 0.68 to 1.38; 15 trials, 1821 participants; moderate-certainty evidence). Local adverse events Within the trials that tested 'treating eczema flare-up' strategies, we identified only 26 cases of abnormal skin thinning from 2266 participants (1% across 22 trials). Most cases were from the use of higher-potency topical corticosteroids (16 with very potent, 6 with potent, 2 with moderate and 2 with mild). We assessed this evidence as low certainty, except for very potent versus potent topical corticosteroids, which was very low-certainty evidence.  Longer versus shorter-term duration of application for induction of remission No trials were identified. Twice weekly application (weekend, or 'proactive therapy') to prevent relapse (flare-ups) versus no topical corticosteroids/reactive application Nine trials assessed this comparison, generally lasting 16 to 20 weeks. We pooled seven trials that compared weekend (proactive) topical corticosteroids therapy versus no topical corticosteroids (1179 participants, children and adults with a range of eczema severities, though mainly moderate or severe). Weekend (proactive) therapy probably results in a large decrease in likelihood of a relapse from 58% to 25% (risk ratio (RR) 0.43, 95% CI 0.32 to 0.57; 7 trials, 1149 participants; moderate-certainty evidence). Local adverse events We did not identify any cases of abnormal skin thinning in seven trials that assessed skin thinning (1050 participants) at the end of treatment. We assessed this evidence as low certainty. Other comparisons  Other comparisons included newer versus older preparations of topical corticosteroids (15 trials), cream versus ointment (7 trials), topical corticosteroids with wet wrap versus no wet wrap (6 trials), number of days per week applied (4 trials), different concentrations of the same topical corticosteroids (2 trials), time of day applied (2 trials), topical corticosteroids alternating with topical calcineurin inhibitors versus topical corticosteroids alone (1 trial), application to wet versus dry skin (1 trial) and application before versus after emollient (1 trial). No trials compared branded versus generic topical corticosteroids and time between application of emollient and topical corticosteroids. AUTHORS' CONCLUSIONS: Potent and moderate topical corticosteroids are probably more effective than mild topical corticosteroids, primarily in moderate or severe eczema; however, there is uncertain evidence to support any advantage of very potent over potent topical corticosteroids. Effectiveness is similar between once daily and twice daily (or more) frequent use of potent topical corticosteroids to treat eczema flare-ups, and topical corticosteroids weekend (proactive) therapy is probably better than no topical corticosteroids/reactive use to prevent eczema relapse (flare-ups). Adverse events were not well reported and came largely from low- or very low-certainty, short-term trials. In trials that reported abnormal skin thinning, frequency was low overall and increased with increasing potency. We found no trials on the optimum duration of treatment of a flare, branded versus generic topical corticosteroids, and time to leave between application of topical corticosteroids and emollient. There is a need for longer-term trials, in people with mild eczema

    Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy

    Get PDF
    AbstractDevelopmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy.</jats:p

    Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation

    Get PDF
    The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5×1034^{34} cm2^{-2}s1^{-1}. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the first prototype module based on the final version of the CMS Binary Chip front-end ASIC before and after the module was irradiated with neutrons. Results demonstrate that the prototype module satisfies the requirements, providing efficient tracking information, after being irradiated with a total fluence comparable to the one expected through the lifetime of the experiment

    Selection of the silicon sensor thickness for the Phase-2 upgrade of the CMS Outer Tracker

    Get PDF
    During the operation of the CMS experiment at the High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker will be exposed to radiation levels that could potentially deteriorate their performance. Previous studies had determined that planar float zone silicon with n-doped strips on a p-doped substrate was preferred over p-doped strips on an n-doped substrate. The last step in evaluating the optimal design for the mass production of about 200 m2^{2} of silicon sensors was to compare sensors of baseline thickness (about 300 μm) to thinned sensors (about 240 μm), which promised several benefits at high radiation levels because of the higher electric fields at the same bias voltage. This study provides a direct comparison of these two thicknesses in terms of sensor characteristics as well as charge collection and hit efficiency for fluences up to 1.5 × 1015^{15} neq_{eq}/cm2^{2}. The measurement results demonstrate that sensors with about 300 μm thickness will ensure excellent tracking performance even at the highest considered fluence levels expected for the Phase-2 Outer Tracker
    corecore