1,774 research outputs found

    The momentum distribution of J/psi in B decays

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    The discrepancy between theory and data in the momentum distribution of slow J/psi in B decays has been several times addressed as a puzzle. Using the most recent results on exclusive B decays into J/psi and heavy kaons or exotic mesons and reconsidering the non-relativistic-QCD calculation of the color octet fragmentation component, we show that an improvement in the comparison between data and theory can be obtained. There is still room for a better fit to data and this may imply that new exotic mesons of the XYZ kind have yet to be discovered.Comment: 4 pages, 2 figures, 2 tables. To appear in Physical Review

    DAMPening Inflammation by Modulating TLR Signalling

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    Damage-associated molecular patterns (DAMPs) include endogenous intracellular molecules released by activated or necrotic cells and extracellular matrix (ECM) molecules that are upregulated upon injury or degraded following tissue damage. DAMPs are vital danger signals that alert our immune system to tissue damage upon both infectious and sterile insult. DAMP activation of Toll-like receptors (TLRs) induces inflammatory gene expression to mediate tissue repair. However, DAMPs have also been implicated in diseases where excessive inflammation plays a key role in pathogenesis, including rheumatoid arthritis (RA), cancer, and atherosclerosis. TLR activation by DAMPs may initiate positive feedback loops where increasing tissue damage perpetuates pro-inflammatory responses leading to chronic inflammation. Here we explore the current knowledge about distinct signalling cascades resulting from self TLR activation. We also discuss the involvement of endogenous TLR activators in disease and highlight how specifically targeting DAMPs may yield therapies that do not globally suppress the immune system

    A complete one-loop calculation of electroweak supersymmetric effects in tt-channel single top production at LHC

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    We have computed the complete one-loop electroweak effects in the MSSM for single top (and single antitop) production in the tt-channel at hadron colliders, generalizing a previous analysis performed for the dominant dtdt final state and fully including QED effects. The results are quite similar for all processes. The overall Standard Model one-loop effect is small, of the few percent size. This is due to a compensation of weak and QED contributions that are of opposite sign. The genuine SUSY contribution is generally quite modest in the mSUGRA scenario. The experimental observables would therefore only practically depend, in this framework, on the CKM WtbWtb coupling.Comment: 25 pages, several eps figures. Update corresponding to published versio

    A quantitative metric for the comparative evaluation of optical clearing protocols for 3D multicellular spheroids

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    3D multicellular spheroids quickly emerged as in vitro models because they represent the in vivo tumor environment better than standard 2D cell cultures. However, with current microscopy technologies, it is difficult to visualize individual cells in the deeper layers of 3D samples mainly because of limited light penetration and scattering. To overcome this problem several optical clearing methods have been proposed but defining the most appropriate clearing approach is an open issue due to the lack of a gold standard metric. Here, we propose a guideline for 3D light microscopy imaging to achieve single-cell resolution. The guideline includes a validation experiment focusing on five optical clearing protocols. We review and compare seven quality metrics which quantitatively characterize the imaging quality of spheroids. As a test environment, we have created and shared a large 3D dataset including approximately hundred fluorescently stained and optically cleared spheroids. Based on the results we introduce the use of a novel quality metric as a promising method to serve as a gold standard, applicable to compare optical clearing protocols, and decide on the most suitable one for a particular experiment

    Massive Spin 3/2 Electrodynamics

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    We study the general non-minimally coupled charged massive spin 3/2 model both for its low energy phenomenological properties and for its unitarity, causality and degrees of freedom behaviour. When the model is viewed as an effective theory, its parameters (after ensuring the correct excitation count) are related to physical characteristics, such as the magnetic moment g factor, by means of low energy theorems. We also provide the corresponding higher spin generalisation. Separately, we consider both low and high energy unitarity, as well as the causality aspects of our models. None (including truncated N=2 supergravity) is free of the minimal model's acausality.Comment: 23 pages, 1 figure, LaTeX and axodraw.sty, novel Majorana-type term included; results unaltere

    Mesenchymal Stem Cell-Derived Extracellular Vesicles Reduce Disease Severity and Immune Responses in Inflammatory Arthritis

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    Abstract Background Novel biological therapies have revolutionised the management of Rheumatoid Arthritis (RA) but no cure currently exists. Mesenchymal stem cells (MSCs) immunomodulate inflammatory responses through paracrine signalling via growth factors, cytokines, chemokines and extracellular vesicles (EVs) in the cell secretome; however, MSCs are still not available in the clinic. We evaluated the therapeutic potential of MSCs-derived EVs in an antigen-induced model of arthritis (AIA). Methods EVs isolated from MSCs in normal (21% O 2 , 5% CO 2 ) or hypoxic (2% O 2 , 5% CO 2 ) culture or from MSCs pre-conditioned with a pro-inflammatory cytokine cocktail were applied into the AIA model. Disease pathology was assessed 3 days post arthritis induction through histopathological analysis of knee joints. Spleens and lymph nodes were collected and assessed for T cell polarisation within the immune response to AIA. Activated naïve CD4+ T cells from spleens of healthy mice were cultured with EVs or MSCs to assess deactivation capabilities. Results All EV treatments significantly reduced knee-joint swelling and histopathological signs of AIA with enhanced responses to normoxic and pro-inflammatory primed EVs. Polarisation of T cells towards CD4+ helper cells expressing IL17a (Th17) was reduced when EV treatments from MSCs cultured in hypoxia or pro-inflammatory priming conditions were applied. Conclusions Hypoxically cultured EVs present a priming methodology that is as effective in reducing swelling, IL-17a expression, Th17 polarisation and T cell proliferation as pro-inflammatory priming. EVs present an effective novel technology for cell-free therapeutic translation in treating inflammatory arthritis and autoimmune disorders such as RA

    State of the Art and New Trends from the 2022 Gism Annual Meeting

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    The 2022 Italian Mesenchymal Stem Cell Group (Gruppo Italiano Staminali Mesenchimali, GISM) Annual Meeting took place on 20–21 October 2022 in Turin (Italy), with the support of the University of Turin and the City of Health and Science of Turin. The novelty of this year’s meeting was its articulation, reflecting the new structure of GISM based on six sections: (1) Bringing advanced therapies to the clinic: trends and strategies, (2) GISM Next Generation, (3) New technologies for 3D culture systems, (4) Therapeutic applications of MSC-EVs in veterinary and human medicine, (5) Advancing MSC therapies in veterinary medicine: present challenges and future perspectives, (6) MSCs: a double-edged sword: friend or foe in oncology. National and international speakers presented their scientific works with the aim of promoting an interactive discussion and training for all attendees. The atmosphere was interactive, where ideas and questions between younger researchers and senior mentors were shared in all moments of the congress

    A Monte-Carlo generator for statistical hadronization in high energy e+e- collisions

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    We present a Monte-Carlo implementation of the Statistical Hadronization Model in e+e- collisions. The physical scheme is based on the statistical hadronization of massive clusters produced by the event generator Herwig within the microcanonical ensemble. We present a preliminary comparison of several observables with measurements in e+e- collisions at the Z peak. Although a fine tuning of the model parameters is not carried out, a general good agreement between its predictions and data is found.Comment: 19 pages, 28 figures, 6 tables. v2: added sections on comparison between the Statistical Hadronization Model and the Cluster Model and on the interplay between Herwig cluster splitting algorithm and Statistical Hadronization Model predictions. Fixed typos and references added. Version accepted for publication in EPJ

    Monte Carlo studies of the jet activity in Higgs + 2 jet events

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    Tree-level studies have shown in the past that kinematical correlations between the two jets in Higgs+2-jet events are direct probes of the Higgs couplings, e.g. of their CP nature. In this paper we explore the impact of higher-order corrections on the azimuthal angle correlation of the two leading jets and on the rapidity distribution of extra jets. Our study includes matrix-element and shower MC effects, for the two leading sources of Higgs plus two jet events at the CERN LHC, namely vector-boson and gluon fusion. We show that the discriminating features present in the previous leading-order matrix element studies survive.Comment: 12 pages, 10 figures. Version to appear on JHEP. Figs. 5-8 replaced with colour version
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