35 research outputs found

    Hyperhomocysteinemia is detrimental to pregnancy in mice and is associated with preterm birth

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    AbstractElevated levels of homocysteine produce detrimental effects in humans but its role in preterm birth is not known. Here we used a mouse model of hyperhomocysteinemia to examine the relevance of homocysteine to preterm birth. The mouse carries a heterozygous deletion of cystathionine β-synthase (Cbs+/−). Gestational period was monitored in wild type and Cbs+/− female mice. Mouse uterine and placental tissues, human primary trophoblast cells, and human myometrial and placental cell lines were used to determine the influence of homocysteine on expression of specific genes in vitro. The activity of BKCa channel in the myometrial cell line was monitored using the patch-clamp technique. We found that hyperhomocysteinemia had detrimental effects on pregnancy and induced preterm birth in mice. Homocysteine increased the expression of oxytocin receptor and Cox-2 as well as PGE2 production in uterus and placenta, and initiated premature uterine contraction. A Cox-2 inhibitor reversed these effects. Gpr109a, a receptor for niacin, induced Cox-2 in uterus. Homocysteine upregulated GPR109A and suppressed BKCa channel activity in human myometrial cells. Deletion of Gpr109a in Cbs+/− mice reversed premature birth. We conclude that hyperhomocysteinemia causes preterm birth in mice through upregulation of the Gpr109a/Cox-2/PGE2 axis and that pharmacological blockade of Gpr109a may have potential in prevention of preterm birth

    Spin and charge ordering in self-doped Mott insulators

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    We have investigated possible spin and charge ordered states in 3d transition-metal oxides with small or negative charge-transfer energy, which can be regarded as self-doped Mott insulators, using Hartree-Fock calculations on d-p-type lattice models. It was found that an antiferromagnetic state with charge ordering in oxygen 2p orbitals is favored for relatively large charge-transfer energy and may be relevant for PrNiO3_3 and NdNiO3_3. On the other hand, an antiferromagnetic state with charge ordering in transition-metal 3dd orbitals tends to be stable for highly negative charge-transfer energy and can be stabilized by the breathing-type lattice distortion; this is probably realized in YNiO3_3.Comment: 4 pages, 4 figure

    Electronic structure of NiS_{1-x}Se_x

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    We investigate the electronic structure of the metallic NiS1x_{1-x}Sex_x system using various electron spectroscopic techniques. The band structure results do not describe the details of the spectral features in the experimental spectrum, even for this paramagnetic metallic phase. However, a parameterized many-body multi-band model is found to be successful in describing the Ni~2pp core level and valence band, within the same model. The asymmetric line shape as well as the weak intensity feature in the Ni~2pp core level spectrum has been ascribed to extrinsic loss processes in the system. The presence of satellite features in the valence band spectrum shows the existence of the lower Hubbard band, deep inside the pdpd metallic regime, consistent with the predictions of the dynamical mean field theory.Comment: To be published in Physical Review B, 18 pages and 5 figure

    The forward physics facility at the high-luminosity LHC

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    High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF's physics potential

    Large-scale phenotyping of patients with long COVID post-hospitalization reveals mechanistic subtypes of disease

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    One in ten severe acute respiratory syndrome coronavirus 2 infections result in prolonged symptoms termed long coronavirus disease (COVID), yet disease phenotypes and mechanisms are poorly understood1. Here we profiled 368 plasma proteins in 657 participants ≥3 months following hospitalization. Of these, 426 had at least one long COVID symptom and 233 had fully recovered. Elevated markers of myeloid inflammation and complement activation were associated with long COVID. IL-1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue and anxiety/depression; MATN2, CSF3 and C1QA were elevated in gastrointestinal symptoms and C1QA was elevated in cognitive impairment. Additional markers of alterations in nerve tissue repair (SPON-1 and NFASC) were elevated in those with cognitive impairment and SCG3, suggestive of brain–gut axis disturbance, was elevated in gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2-specific immunoglobulin G (IgG) was persistently elevated in some individuals with long COVID, but virus was not detected in sputum. Analysis of inflammatory markers in nasal fluids showed no association with symptoms. Our study aimed to understand inflammatory processes that underlie long COVID and was not designed for biomarker discovery. Our findings suggest that specific inflammatory pathways related to tissue damage are implicated in subtypes of long COVID, which might be targeted in future therapeutic trials

    SARS-CoV-2-specific nasal IgA wanes 9 months after hospitalisation with COVID-19 and is not induced by subsequent vaccination

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    BACKGROUND: Most studies of immunity to SARS-CoV-2 focus on circulating antibody, giving limited insights into mucosal defences that prevent viral replication and onward transmission. We studied nasal and plasma antibody responses one year after hospitalisation for COVID-19, including a period when SARS-CoV-2 vaccination was introduced. METHODS: In this follow up study, plasma and nasosorption samples were prospectively collected from 446 adults hospitalised for COVID-19 between February 2020 and March 2021 via the ISARIC4C and PHOSP-COVID consortia. IgA and IgG responses to NP and S of ancestral SARS-CoV-2, Delta and Omicron (BA.1) variants were measured by electrochemiluminescence and compared with plasma neutralisation data. FINDINGS: Strong and consistent nasal anti-NP and anti-S IgA responses were demonstrated, which remained elevated for nine months (p < 0.0001). Nasal and plasma anti-S IgG remained elevated for at least 12 months (p < 0.0001) with plasma neutralising titres that were raised against all variants compared to controls (p < 0.0001). Of 323 with complete data, 307 were vaccinated between 6 and 12 months; coinciding with rises in nasal and plasma IgA and IgG anti-S titres for all SARS-CoV-2 variants, although the change in nasal IgA was minimal (1.46-fold change after 10 months, p = 0.011) and the median remained below the positive threshold determined by pre-pandemic controls. Samples 12 months after admission showed no association between nasal IgA and plasma IgG anti-S responses (R = 0.05, p = 0.18), indicating that nasal IgA responses are distinct from those in plasma and minimally boosted by vaccination. INTERPRETATION: The decline in nasal IgA responses 9 months after infection and minimal impact of subsequent vaccination may explain the lack of long-lasting nasal defence against reinfection and the limited effects of vaccination on transmission. These findings highlight the need to develop vaccines that enhance nasal immunity. FUNDING: This study has been supported by ISARIC4C and PHOSP-COVID consortia. ISARIC4C is supported by grants from the National Institute for Health and Care Research and the Medical Research Council. Liverpool Experimental Cancer Medicine Centre provided infrastructure support for this research. The PHOSP-COVD study is jointly funded by UK Research and Innovation and National Institute of Health and Care Research. The funders were not involved in the study design, interpretation of data or the writing of this manuscript

    Photoemission study of electronic excitations at clean metal surfaces and thin metal films

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