848 research outputs found

    Lossy Multi/Hyperspectral Compression HW Implementation at high data rate

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    Image compression is becoming more and more important, as new multispectral and hyperspectral instruments are going to generate very high data rates due to the increased spatial and spectral resolutions. Transmitting all the acquired data to the ground segment is a serious bottleneck, and compression techniques are a feasible solution to this problem. The CCSDS has established a working group (WG) on multispectral and Hyperspectral Data Compression (MHDC), which has the purpose of standardizing compression techniques to be used onboard. The WG has already standardized a lossless compression algorithm for multispectral and hyperspectral images, and has started working on a lossy compression algorithm. The complexity of lossless compression algorithms is typically larger than that of lossy ones, leading to potentially lower throughputs. Therefore, a careful assessment is required in order to identify techniques that are able to sustain very high data rates. The increased complexity can also lead to increased resource occupancy on a hardware device such as an FPGA. Lossy compression introduces information losses in the images, and these losses must be accurately characterized, and their effect on the applications investigated. For these reasons, developing a lossy algorithm requires a more elaborate process. Under an ESA contract primed by Politecnico of Torino, TSD is currently designing an IP core for FPGA and/or ASIC implementation of a lossy compression algorithm that is being proposed for CCSDS standardization. In addition to the IP core, TSD is developing a HW platform based on the Xilinx Virtex-5 XQR5VFX130, the industry's first high performance rad-hard reconfigurable FPGA for processing-intensive for space systems. Advanced results along with details of electronic platform design will be presented in this paper

    Multiplex staining depicts the immune infiltrate in colitis-induced colon cancer model

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    Assessment of the host immune response pattern is of increasing importance as highly prognostic and diagnostic, in immune-related diseases and in some types of cancer. Chronic inflammation is a major hallmark in colon cancer formation, but, despite the extent of local inflammatory infiltrate has been demonstrated to be extremely informative, its evaluation is not routinely assessed due to the complexity and limitations of classical immunohistochemistry (IHC). In the last years, technological advance helped in bypassing technical limits, setting up multiplex IHC (mIHC) based on tyramide signal amplification (TSA) method and designing software suited to aid pathologists in cell scoring analysis. Several studies verified the efficacy of this method, but they were restricted to the analysis of human samples. In the era of translational medicine the use of animal models to depict human pathologies, in a more complete and complex approach, is really crucial. Nevertheless, the optimization and validation of this method to species other than human is still poor. We took advantage of Multispectral Imaging System to identify the immunoprofile of Dextran Sulphate Sodium (DSS)-treated mouse colon. We optimized a protocol to sequentially stain formalin fixed paraffin embedded murine colon samples for CD3, CD8a, CD4, and CD4R5B0 antigens. With this approach we obtained a detailed lymphocyte profile, while preserving the morphological tissue context, generally lost with techniques like gene expression profiling or flow cytometry. This study, comparing the results obtained by mIHC with immunophenotyping performed with cytofluorimetric and standard IHC methods validates the potentiality and the applicability of this innovative approach

    Preliminary evidence of blunted humoral response to SARS-CoV-2 mRNA vaccine in multiple sclerosis patients treated with ocrelizumab

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    Objectives: Several concerns regard the immunogenicity of SARS-CoV-2 vaccines in people with multiple sclerosis (pwMS), since the majority of them is treated with immunomodulating/immunosuppressive disease modifying therapies. Here we report the first data on the humoral response to mRNA SARS-CoV-2 vaccine in a case series of 4 pwMS treated with ocrelizumab (OCR) as compared to a group of healthy subjects (HS). Methods: We collected serum samples at 0, 14, 21 days after the first dose and 7 days after the second dose of BNT162b2-mRNA-Covid-19 vaccine from 55 health-care workers and 4 relapsing pwMS on OCR, with no history of Covid-19 infection. Sera were tested using the LIAISON®SARS-CoV-2 TrimericS-IgG assay (DiaSorin-S.p.A.) for the detection of IgG antibodies to SARS-CoV-2 spike protein. The anti-spike IgGtiters were expressed in Binding Antibody Units (BAU), an international standard unit. Results: At baseline all subjects were negative for anti-spike IgG. Seven days after the second dose of vaccine all HS mounted a significant humoral response (geometric mean 2010.4 BAU/mL C.I. 95% 1512.7-2672) while the 4 pwMS showed a lower response (range <4.81-175 BAU/mL). Discussion: Humoral response to BNT162b2-mRNA-vaccine in pwMS treated with OCR was clearly blunted. Further data are urgently needed to confirm and expand these preliminary results and to develop strategies to optimize the response to SARSCoV-2 vaccines in pwMS on OCR

    Neapolitan volcanic area Tide Gauge Network (Southern Italy): Ground Displacements and Sea-Level Oscillations

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    Abstract. In this study, we investigate the oscillations of relative sea level through the analysis of tide gauge records about 10-year long collected in the Gulfs of Pozzuoli and Napoli (Southern Italy). The main goal of this study is to provide a suitable resolution model of the sea tides including low frequency (seiches), tidal bands and non-linear tides. The spectral analyses of the tide gauge records lead us to identify a number of seiche periods some of them already known from the literature and some other unknown. Furthermore, we target a non-conventional purpose of the tidal analysis, namely extracting from the tide gauge records the volcano-tectonic signal (vertical ground displacement) in the resurgent Campi Flegrei caldera. We suggest a method to filter out the volcano-tectonic signal (bradyseism) from the tide gauge records by deconvolving it from two records, one collected in the active volcanic area (Pozzuoli) and the other one collected in a tectonically stable station (Napoli), located beyond the caldera rim. Finally, we retrieve the relative mean sea level change in the Gulf of Naples and compare it with the trend found in five tide gauges spread along the Italian coast

    Slow wind belt in the quiet solar corona

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    The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 R⊙R_\odot to 7.0 R⊙R_\odot, is formed by a slow and dense wind stream running along the coronal current sheet, accelerating in the radial direction and reaching at 6.8 R⊙R_\odot a speed within 150 km s−1^{-1} and 190 km s−1^{-1}, depending on the assumptions on the velocity distribution of the neutral hydrogen atoms in the coronal plasma. The slow stream is separated by thin regions of high velocity shear from faster streams, almost symmetric relative to the current sheet, with peak velocity within 175 km s−1^{-1} and 230 km s−1^{-1} at the same coronal level. The density-velocity structure of the slow wind zone is discussed in terms of the expansion factor of the open magnetic field lines that is known to be related to the speed of the quasi-steady solar wind, and in relation to the presence of a web of quasi separatrix layers, S-web, the potential sites of reconnection that release coronal plasma into the wind. The parameters characterizing the coronal magnetic field lines are derived from 3D MHD model calculations. The S-web is found to coincide with the latitudinal region where the slow wind is observed in the outer corona and is surrounded by thin layers of open field lines expanding in a non-monotonic way

    PLGA-g-PVP -based nanocapsules for the controlled delivery of antimalarials

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    Amphiphilic PLGA-g-PVP copolymers with different PLGA and PVP content were recently obtained by the radical polymerization of 1-vinylpyrrolidin-2-one in liquid poly(lactic-co-glycolic acid) (PLGA) (50:50) at 100\ub0C. Saponification of the PLGA portion allowed isolating the PVP side chains and measuring their molecular weight, which turned to be lower than the threshold for glomerular filtration. The orthogonal solvent pair ethyl acetate-methanol gave PLGA-g-PVP fractions with different PLGA and PVP content. Following the same procedure, PLGA/PVP blends gave the two homopolymers. PLGA-g-PVP and PLGA/PLGA-g-PVP blends, but not PLGA/PVP blends, gave long-term stable nanodispersions in water. In this work, PLGA-g-PVP copolymers were employed to obtain novel artemisinin and curcumin formulations. Both drugs are endowed with potential and pitfalls for malaria treatment. Artemisinin is a potent Plasmodium falciparum malaria parasite inhibitor (IC50 = 10-8 - 10-7 M) but with low bioavailability, poor pharmacokinetic properties and high cost. Curcumin inhibits the growth of P. falciparum with a dose dependent trend and IC50 = 5 \u3bcM. Despite the absence of secondary effects in humans, the use of curcumin is limited by the low solubility in water, the high chemical instability and photosensitivity, resulting in low bioavailability. To increase bioavailability, artemisinin and curcumin were loaded into nanocapsules consisting of a biocompatible oily core acting as drug solvents, and a PLGA-g-PVP shell. Loaded nanocapsules were characterized in terms of morphology, physico-chemical properties and release tests. In particular, transmission electron microscopy (TEM) showed spherical morphologies and dynamic scattering measurements (DLS) revealed size in the range 50 - 100 nm. The encapsulation efficiency was very high with both drugs and in the case of artemisinin it approached 100%. All formulations showed long-term shelf stability in aqueous solution. In vitro activity tests as P. falciparum inhibitors are currently in progress
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