128 research outputs found

    Quali-quantitative differences of adipose tissuederived stromal cells from superficial and deep subcutaneous lipoaspirates: a matter of fat

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    Subcutaneous fat (or hypoderm) represents a valuable reservoir of adiposederived stem cells (ASCs), residing in the stromal vascular fraction (SVF), widely exploited in regenerative medicine applications, being easily harvested through lipoaspiration. The lack for standardized procedures for autologous fat grafting, guided research efforts aimed at identifying possible differences related to the harvesting site, that may affect cell isolation yield, cell growth properties and clinical outcomes. The hypoderm features a complex architecture: the superficial fascia separates the superficial adipose tissue (SAT) from the deep layer (DAT). Aim of this study was to unravel the differences between SAT and DAT, considering morphological structure, SVF composition and ASCs’ properties. SAT and DAT specimens were collected from three distinct anatomical regions (abdomen, thigh and knee) of female individuals and comparatively analyzed through histology, flow citometry, and qPCR. ASCs were isolated in primary culture and used for in vitro differentiation assays. Our results indicated that liposucted SAT contains a higher stromal tissue compound, along with a higher proportion of CD105-positive cells, compared to DAT from the same anatomical region. Also, cells isolated from SAT displayed increased multipotency and stemness features. All differences were mainly evidenced in specimens harvested from the abdominal region. According to our results, SAT features overall increased stem properties. Given that subcutaneous adipose tissue is currently exploited as the gold standard source for high yield isolation of somatic stem cells, these results may provide precious hints toward defining a prioritization of tissue harvesting site for regenerative medicine applications

    Long-term mortality in HIV patients virally suppressed for more than three years with incomplete CD4 recovery: A cohort study

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    <p>Abstract</p> <p>Background</p> <p>The mortality in patients with persistent low CD4 count despite several years of HAART with sustained viral suppression is poorly documented. We aimed to identify predictors for inadequate CD4 cell recovery and estimate mortality in patients with low CD4 count but otherwise successful HAART.</p> <p>Method</p> <p>In a nationwide cohort of HIV patients we identified all individuals who started HAART before 1 January 2005 with CD4 cell count ≤ 200 cells/μL and experienced three years with sustained viral suppression. Patients were categorized according to CD4 cell count after the three years suppressed period (≤ 200 cells/μL; immunological non-responders (INRs), >200 cells/μL; immunological responders (IRs)). We used logistic regression and Kaplan-Meier analysis to estimated risk factors and mortality for INRs compared to IRs.</p> <p>Results</p> <p>We identified 55 INRs and 236 IRs. In adjusted analysis age > 40 years and > one year from first CD4 cell count ≤ 200 cells/μL to start of the virologically suppressed period were associated with increased risk of INR. INRs had substantially higher mortality compared to IRs. The excess mortality was mainly seen in the INR group with > one year of immunological suppression prior to viral suppression and injection drug users (IDUs).</p> <p>Conclusion</p> <p>Age and prolonged periods of immune deficiency prior to successful HAART are risk factors for incomplete CD4 cell recovery. INRs have substantially increased long-term mortality mainly associated with prolonged immunological suppression prior to viral suppression and IDU.</p

    Measurement of the charge asymmetry of electrons from the decays of W bosons produced in pp\overline{pp} collisions at s\sqrt{s} =1.96 TeV

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    At the Fermilab Tevatron proton-antiproton (pp\overline{pp}) collider, high-mass electron-neutrino (eν) pairs are produced predominantly in the process pp\overline{pp}→W(→eν)+X. The asymmetry of the electron and positron yield as a function of their pseudorapidity constrain the slope of the ratio of the u- to d-quark parton distributions versus the fraction of the proton momentum carried by the quarks. This paper reports on the measurement of the electron-charge asymmetry using the full data set recorded by the Collider Detector at Fermilab in 2001–2011 and corresponding to 9.1 fb1^{-1} of integrated luminosity. The measurement significantly improves the precision of the Tevatron constraints on the parton-distribution functions of the proton. Numerical tables of the measurement are provided

    EUSO-SPB2 Telescope Optics and Testing

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    The Extreme Universe Space Observatory - Super Pressure Balloon (EUSO-SPB2) mission will fly two custom telescopes that feature Schmidt optics to measure Cherenkov- and fluorescence emission of extensive air showers from cosmic rays at the PeV and EeV-scale, and search for τ-neutrinos. Both telescopes have 1-meter diameter apertures and UV/UV-visible sensitivity. The Cherenkov telescope uses a bifocal mirror segment alignment, to distinguish between a direct cosmic ray that hits the camera versus the Cherenkov light from outside the telescope. Telescope integration and laboratory calibration will be performed in Colorado. To estimate the point spread function and efficiency of the integrated telescopes, a test beam system that delivers a 1-meter diameter parallel beam of light is being fabricated. End-to-end tests of the fully integrated instruments will be carried out in a field campaign at dark sites in the Utah desert using cosmic rays, stars, and artificial light sources. Laser tracks have long been used to characterize the performance of fluorescence detectors in the field. For EUSO-SPB2 an improvement in the method that includes a correction for aerosol attenuation is anticipated by using a bi-dynamic Lidar configuration in which both the laser and the telescope are steerable. We plan to conduct these field tests in Fall 2021 and Spring 2022 to accommodate the scheduled launch of EUSO-SPB2 in 2023 from Wanaka, New Zealand

    EUSO-SPB1 mission and science

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    The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of ⪆ 3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search

    Expected Performance of the EUSO-SPB2 Fluorescence Telescope

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    The Extreme Universe Space Observatory Super Pressure Balloon 2 (EUSO-SPB2) is under development, and will prototype instrumentation for future satellite-based missions, including the Probe of Extreme Multi-Messenger Astrophysics (POEMMA). EUSO-SPB2 will consist of two telescopes. The first is a Cherenkov telescope (CT) being developed to identify and estimate the background sources for future below-the-limb very high energy (E>10 PeV) astrophysical neutrino observations, as well as above-the-limb cosmic ray induced signals (E>1 PeV). The second is a fluorescence telescope (FT) being developed for detection of Ultra High Energy Cosmic Rays (UHECRs). In preparation for the expected launch in 2023, extensive simulations tuned by preliminary laboratory measurements have been performed to understand the FT capabilities. The energy threshold has been estimated at 1018.2^{18.2} eV, and results in a maximum detection rate at 1018.6^{18.6} eV when taking into account the shape of the UHECR spectrum. In addition, onboard software has been developed based on the simulations as well as experience with previous EUSO missions. This includes a level 1 trigger to be run on the computationally limited flight hardware, as well as a deep learning based prioritization algorithm in order to accommodate the balloon’s telemetry budget. These techniques could also be used later for future, space-based missions

    EUSO@TurLab project in view of Mini-EUSO and EUSO-SPB2 missions

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    The TurLab facility is a laboratory, equipped with a 5 m diameter and 1 m depth rotating tank, located in the fourth basement level of the Physics Department of the University of Turin. In the past years, we have used the facility to perform experiments related to the observations of Extreme Energy Cosmic Rays (EECRs) from space using the fluorescence technique for JEM-EUSO missions with the main objective to test the response of the trigger logic. In the missions, the diffuse night brightness and artificial and natural light sources can vary significantly in time and space in the Field of View (FoV) of the telescope. Therefore, it is essential to verify the detector performance and test the trigger logic under such an environment. By means of the tank rotation, a various terrestrial surface with the different optical characteristics such as ocean, land, forest, desert and clouds, as well as artificial and natural light sources such as city lights, lightnings and meteors passing by the detector FoV one after the other is reproduced. The fact that the tank is located in a very dark place enables the tests under an optically controlled environment. Using the Mini-EUSO data taken since 2019 onboard the ISS, we will report on the comparison between TurLab and ISS measurements in view of future experiments at TurLab. Moreover, in the forthcoming months we will start testing the trigger logic of the EUSO-SPB2 mission. We report also on the plans and status for this purpose
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