774 research outputs found

    Third trimester intrauterine fetal death: proposal for the assessment of the chronology of umbilical cord and placental thrombosis

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    : The timing of umbilical cord and placental thrombosis in the third trimester intrauterine fetal death (TT-IUFD) may be fundamental for medico-legal purposes, when it undergoes medical litigation due to the absence of risk factors. Authors apply to human TT-IUFD cases a protocol, which includes histochemistry and immunohistochemistry (IHC) for the assessment of thrombi's chronology. A total of 35 thrombi of umbilical cord and/or placenta were assessed: 2 in umbilical artery, 6 in umbilical vein, 15 in insertion, 10 in chorionic vessels, 1 in fetal renal vein, 1 in fetal brachiocephalic vein. Thrombi's features were evaluated with hematoxylin-eosin, Picro-Mallory, Von Kossa, Perls, and immunohistochemistry for CD15, CD68, CD31, CD61, and Smooth Muscle Actin. The estimation of the age of the thrombi was established by applying neutrophils/macrophages ratio taking into consideration, according to literature, the presence of hemosiderophagi, calcium deposition, and angiogenesis. To estimate an approximate age of fresh thrombi (< 1 day), a non-linear regression model was tested. Results were compared to maternal risk factors, fetal time of death estimated at autopsy, mechanism, and cause of death. Our study confirms that the maternal risk factors for fetal intrauterine death and the pathologies of the cord, followed by those of the placental parenchyma, are the conditions that are most frequently associated with the presence of thrombi. Results obtained with histological stainings document that the neutrophile/macrophage ratio is a useful tool for determining placental thrombi's age. Age estimation of thrombi on the first day is very challenging; therefore, the study presented suggests the N/M ratio as a parameter to be used, together with others, i.e., hemosiderophagi, calcium deposition, and angiogenesis, for thrombi's age determination, and hypothesizes that its usefulness regards particularly the first days when all other parameters are negative

    Are mast cells implicated in asphyxia?

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    In a previous immunohistochemical (IHC) study, we documented the reaction of lung tissue vessels to hypoxia through the immunodetection of HIF1-α protein, a key regulator of cellular response to hypoxic conditions. Findings showing that asphyxia deaths are associated with an increase in the number of mast cell (MC)-derived tryptase enzymes in the blood suggests that HIF1-α production may be correlated with MC activation in hypoxic conditions. This hypothesis prompted us to investigate the possible role of pulmonary MC in acute asphyxia deaths. Lung of 47 medico-legal autopsy cases (35 asphyxia/hypoxia deaths, 11 controls, and 1 anaphylactic death) were processed by IHC analysis using anti-CD117 (c-Kit) antibody to investigate peri-airway and perivascular MC together with their counts and features. Results showed a significant increase in peri-vascular c-kit+ MC in some asphyxia deaths, such as hanging, strangulation, and aspiration deaths. A strong activation of MC in peri-airway and peri-vascular areas was also observed in lung samples from the anaphylaxis case, which was used as a positive control. Our study points to the potential role of MC in hypoxia and suggests that an evaluation of MC in the lungs may be a useful parameter when forensic pathologists are required to make a differential diagnosis between acute asphyxia deaths and other kinds of death

    Search for spontaneous muon emission from lead nuclei

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    We describe a possible search for muonic radioactivity from lead nuclei using the base elements ("bricks" composed by lead and nuclear emulsion sheets) of the long-baseline OPERA neutrino experiment. We present the results of a Monte Carlo simulation concerning the expected event topologies and estimates of the background events. Using few bricks, we could reach a good sensitivity level.Comment: 12 pages, 4 figure

    Planck LFI: Comparison Between Galaxy Straylight Contamination and other Systematic Effects

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    The straylight contamination due to the Galactic emission (GSC, Galaxy Straylight Contamination) entering at large angles from the antenna centre direction may be one of the most critical sources of systematic effects in observations of the cosmic microwave background (CMB) anisotropies by future satellite missions like {\sc Planck} and MAP. We describe here different methods to evaluate the impact of this effect and compare it with other systematics of instrumental and astrophysical origin. The contributions within few degrees from the beam centre dominate the GSC near the Galaxy plane. The antenna sidelobes at intermediate and large angles from the beam centre dominate the GSC at medium and high Galactic latitudes. We find a GSC peak at 15μ\sim 15\muK and a GSC angular power spectrum above that of the white noise for multipoles \ell \lsim 10 albeit smaller than that of CMB anisotropies by a factor larger than 10\sim 10. Although the GSC is largest at low Galactic latitudes, the contamination produced by far pattern features at medium and high Galactic latitudes, peaking at 4μ\sim 4\muK, has to be carefully investigated, because the combination of low amplitude of Galaxy emission in those regions with the extremely good nominal {\sc Planck} sensitivity naturally makes high Galactic latitude areas the targets for unprecedentedly precise estimation of cosmological CMB anisotropy.Comment: 15 pages, submitted to A&

    Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster

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    Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle θ13\theta_{13} in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small L/EL/E, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current νμ\nu_{\mu} disappearance tension with νe\nu_e appearance and disappearance at the eV mass scale. Instead, a new CERN neutrino beam would allow a further span in the parameter space together with a refined control of systematics and, more relevant, the measurement of the antineutrino sector, by upgrading the spectrometer with detectors currently under R&D study.Comment: 76 pages, 52 figure

    Procedure for short-lived particle detection in the OPERA experiment and its application to charm decays

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    The OPERA experiment, designed to perform the first observation of νμντ\nu_\mu \rightarrow \nu_\tau oscillations in appearance mode through the detection of the τ\tau leptons produced in ντ\nu_\tau charged current interactions, has collected data from 2008 to 2012. In the present paper, the procedure developed to detect τ\tau particle decays, occurring over distances of the order of 1 mm from the neutrino interaction point, is described in detail. The results of its application to the search for charmed hadrons are then presented as a validation of the methods for ντ\nu_\tau appearance detection

    Determination of the muon charge sign with the dipolar spectrometers of the OPERA experiment

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    The OPERA long-baseline neutrino-oscillation experiment has observed the direct appearance of ντ\nu_\tau in the CNGS νμ\nu_\mu beam. Two large muon magnetic spectrometers are used to identify muons produced in the τ\tau leptonic decay and in νμCC\nu_\mu^{CC} interactions by measuring their charge and momentum. Besides the kinematic analysis of the τ\tau decays, background resulting from the decay of charmed particles produced in νμCC\nu_\mu^{CC} interactions is reduced by efficiently identifying the muon track. A new method for the charge sign determination has been applied, via a weighted angular matching of the straight track-segments reconstructed in the different parts of the dipole magnets. Results obtained for Monte Carlo and real data are presented. Comparison with a method where no matching is used shows a significant reduction of up to 40\% of the fraction of wrongly determined charges.Comment: 10 pages. Improvements in the tex
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