379 research outputs found

    Brain Iron and Metabolic Abnormalities in C19orf12 Mutation Carriers: A 7.0 Tesla MRI Study in Mitochondrial Membrane Protein–Associated Neurodegeneration

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    Background Mitochondrial membrane protein‐associated neurodegeneration is an autosomal‐recessive disorder caused by C19orf12 mutations and characterized by iron deposits in the basal ganglia. Objectives The aim of this study was to quantify iron concentrations in deep gray matter structures using quantitative susceptibility mapping MRI and to characterize metabolic abnormalities in the pyramidal pathway using 1H MR spectroscopy in clinically manifesting membrane protein‐associated neurodegeneration patients and asymptomatic C19orf12 gene mutation heterozygous carriers. Methods We present data of 4 clinically affected membrane protein‐associated neurodegeneration patients (mean age: 21.0 ± 2.9 years) and 9 heterozygous gene mutation carriers (mean age: 50.4 ± 9.8 years), compared to age‐matched healthy controls. MRI assessments were performed on a 7.0 Tesla whole‐body system, consisting of whole‐brain gradient‐echo scans and short echo time, single‐volume MR spectroscopy in the white matter of the precentral/postcentral gyrus. Quantitative susceptibility mapping, a surrogate marker for iron concentration, was performed using a state‐of‐the‐art multiscale dipole inversion approach with focus on the globus pallidus, thalamus, putamen, caudate nucleus, and SN. Results and Conclusion In membrane protein‐associated neurodegeneration patients, magnetic susceptibilities were 2 to 3 times higher in the globus pallidus (P = 0.02) and SN (P = 0.02) compared to controls. In addition, significantly higher magnetic susceptibility was observed in the caudate nucleus (P = 0.02). Non‐manifesting heterozygous mutation carriers exhibited significantly increased magnetic susceptibility (relative to controls) in the putamen (P = 0.003) and caudate nucleus (P = 0.001), which may be an endophenotypic marker of genetic heterozygosity. MR spectroscopy revealed significantly increased levels of glutamate, taurine, and the combined concentration of glutamate and glutamine in membrane protein‐associated neurodegeneration, which may be a correlate of corticospinal pathway dysfunction frequently observed in membrane protein‐associated neurodegeneration patients

    All-In-One: Advanced preparation of Human Parenchymal and Non-Parenchymal Liver Cells

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    BACKGROUND & AIMS: Liver cells are key players in innate immunity. Thus, studying primary isolated liver cells is necessary for determining their role in liver physiology and pathophysiology. In particular, the quantity and quality of isolated cells are crucial to their function. Our aim was to isolate a large quantity of high-quality human parenchymal and non-parenchymal cells from a single liver specimen. METHODS: Hepatocytes, Kupffer cells, liver sinusoidal endothelial cells, and stellate cells were isolated from liver tissues by collagenase perfusion in combination with low-speed centrifugation, density gradient centrifugation, and magnetic-activated cell sorting. The purity and functionality of cultured cell populations were controlled by determining their morphology, discriminative cell marker expression, and functional activity. RESULTS: Cell preparation yielded the following cell counts per gram of liver tissue: 2.0+/-0.4x107 hepatocytes, 1.8+/-0.5x106 Kupffer cells, 4.3+/-1.9x105 liver sinusoidal endothelial cells, and 3.2+/-0.5x105 stellate cells. Hepatocytes were identified by albumin (95.5+/-1.7%) and exhibited time-dependent activity of cytochrome P450 enzymes. Kupffer cells expressed CD68 (94.5+/-1.2%) and exhibited phagocytic activity, as determined with 1mum latex beads. Endothelial cells were CD146+ (97.8+/-1.1%) and exhibited efficient uptake of acetylated low-density lipoprotein. Hepatic stellate cells were identified by the expression of alpha-smooth muscle actin (97.1+/-1.5%). These cells further exhibited retinol (vitamin A)-mediated autofluorescence. CONCLUSIONS: Our isolation procedure for primary parenchymal and non-parenchymal liver cells resulted in cell populations of high purity and quality, with retained physiological functionality in vitro. Thus, this system may provide a valuable tool for determining liver function and disease

    How is the economic crisis socially assessed?

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    Based on the Social Representation Theory, the purpose of this article is to explore how lay-people consider both the economic crisis and risk, and to link these social representations to behavior. The article offers an original approach with the articulation of two studies about the social construction of risk and crises. It also contributes to the development of research methods for studying the connections between representations and practical implications. Based on this, the impact of the social representation of the crisis on the perceived ability to act is approached. The first study focuses on free-association tasks, with two distinct target terms: ‘risk’ and ‘crisis’. The structural approach, with a prototypical analysis, allowed the identification of two different representations: (1) for risk, ‘danger’ is the central element; (2) for crisis, ‘economy’ and ‘money’ constitute the main components of the representation. The second study investigates the links between the two previously detected structures and their relations with the perceived ability to act in a financial crisis context. Some aspects of social knowledge were found to have an impact on perceived ability to act

    Observation of the decays B(s)0Ds1(2536)K±B_{(s)}^{0}\to D_{s1}(2536)^{\mp}K^{\pm}

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    This paper reports the observation of the decays B(s)0Ds1(2536)K±B_{(s)}^{0}\to D_{s1}(2536)^{\mp}K^{\pm} using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9fb19\,\mathrm{fb}^{-1}. The branching fractions of these decays are measured relative to the normalisation channel B0D0K+KB^{0}\to \overline{D}^{0}K^{+}K^{-}. The Ds1(2536)D_{s1}(2536)^{-} meson is reconstructed in the D(2007)0K\overline{D}^{*}(2007)^{0}K^{-} decay channel and the products of branching fractions are measured to be B(Bs0Ds1(2536)K±)×B(Ds1(2536)D(2007)0K)=(2.49±0.11±0.12±0.25±0.06)×105,\mathcal{B}(B_{s}^{0}\to D_{s1}(2536)^{\mp}K^{\pm})\times\mathcal{B}(D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-})=(2.49\pm0.11\pm0.12\pm0.25\pm0.06)\times 10^{-5}, B(B0Ds1(2536)K±)×B(Ds1(2536)D(2007)0K)=(0.510±0.021±0.036±0.050)×105.\mathcal{B}(B^{0}\to D_{s1}(2536)^{\mp}K^{\pm})\times\mathcal{B}(D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-}) = (0.510\pm0.021\pm0.036\pm0.050)\times 10^{-5}. The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the B0D0K+KB^{0}\to \overline{D}^{0}K^{+}K^{-} normalisation channel. The last uncertainty in the Bs0B_{s}^{0} result is due to the limited knowledge of the fragmentation fraction ratio, fs/fdf_{s}/f_{d}. The significance for the Bs0B_{s}^{0} and B0B^{0} signals is larger than 10σ10\,\sigma. The ratio of the helicity amplitudes which governs the angular distribution of the Ds1(2536)D(2007)0KD_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-} decay is determined from the data. The ratio of the SS- and DD-wave amplitudes is found to be 1.11±0.15±0.061.11\pm0.15\pm 0.06 and its phase 0.70±0.09±0.040.70\pm0.09\pm 0.04 rad, where the first uncertainty is statistical and the second systematic.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-014.html (LHCb public pages

    Measurement of antiproton production from antihyperon decays in pHe collisions at √sNN=110GeV

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    The interpretation of cosmic antiproton flux measurements from space-borne experiments is currently limited by the knowledge of the antiproton production cross-section in collisions between primary cosmic rays and the interstellar medium. Using collisions of protons with an energy of 6.5 TeV incident on helium nuclei at rest in the proximity of the interaction region of the LHCb experiment, the ratio of antiprotons originating from antihyperon decays to prompt production is measured for antiproton momenta between 12 and 110GeV\!/c . The dominant antihyperon contribution, namely Λ¯ → p¯ π+ decays from promptly produced Λ¯ particles, is also exclusively measured. The results complement the measurement of prompt antiproton production obtained from the same data sample. At the energy scale of this measurement, the antihyperon contributions to antiproton production are observed to be significantly larger than predictions of commonly used hadronic production models

    Measurement of τL using the Bs0 →J/ψη decay mode

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    Using a proton–proton collision data sample collected by the LHCb detector and corresponding to an integrated luminosity of 5.7fb-1 , the lifetime of the light Bs0 mass eigenstate, τL , is measured using the Bs0→J/ψη decay mode to be τL=1.445±0.016(stat)±0.008(syst)ps. A combination of this result with a previous LHCb analysis using an independent dataset corresponding to 3 fb - 1 of integrated luminosity gives τL=1.452±0.014±0.007±0.002ps, where the first uncertainty is statistical, the second due to the uncorrelated part of the systematic uncertainty and the third due to the correlated part of the systematic uncertainty

    Fraction of χc\chi_c decays in prompt J/ψJ/\psi production measured in pPb collisions at sNN=8.16\sqrt{s_{NN}}=8.16 TeV

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    The fraction of χc1\chi_{c1} and χc2\chi_{c2} decays in the prompt J/ψJ/\psi yield, Fχc=σχcJ/ψ/σJ/ψF_{\chi c}=\sigma_{\chi_c \to J/\psi}/\sigma_{J/\psi}, is measured by the LHCb detector in pPb collisions at sNN=8.16\sqrt{s_{NN}}=8.16 TeV. The study covers the forward (1.5<y<4.01.5<y^*<4.0) and backward (5.0<y<2.5-5.0<y^*<-2.5) rapidity regions, where yy^* is the J/ψJ/\psi rapidity in the nucleon-nucleon center-of-mass system. Forward and backward rapidity samples correspond to integrated luminosities of 13.6 ±\pm 0.3 nb1^{-1} and 20.8 ±\pm 0.5 nb1^{-1}, respectively. The result is presented as a function of the J/ψJ/\psi transverse momentum pT,J/ψp_{T,J/\psi} in the range 1<pT,J/ψ<20<p_{T, J/\psi}<20 GeV/cc. The FχcF_{\chi c} fraction at forward rapidity is compatible with the LHCb measurement performed in pppp collisions at s=7\sqrt{s}=7 TeV, whereas the result at backward rapidity is 2.4 σ\sigma larger than in the forward region for 1<pT,J/ψ<31<p_{T, J/\psi}<3 GeV/cc. The increase of FχcF_{\chi c} at low pT,J/ψp_{T, J/\psi} at backward rapidity is compatible with the suppression of the ψ\psi(2S) contribution to the prompt J/ψJ/\psi yield. The lack of in-medium dissociation of χc\chi_c states observed in this study sets an upper limit of 180 MeV on the free energy available in these pPb collisions to dissociate or inhibit charmonium state formation.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-028.html (LHCb public pages
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