32 research outputs found

    Lymphoplasmacyte-rich meningioma with hematologic signs and PD-L1 over-expression

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    Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of grade I meningiomas. It can be clinically associated with prominent peripheral blood abnormalities, anemia, and/or various gammopathy, which usually disappear after surgical removal of the tumor. We document a case of right frontal LPRM in a 72-year-old male who presented general cognitive decadence. The patient suffered from mild anemia. The LPRM is a rare variant of meningioma, with only a few cases globally reported in the literature. It has been categorized as a grade I tumor in the 2021 World Health Organization (WHO) classification central nervous system. Due to the rarity, this meningioma variant origin and biological behavior are still not clear. Immunohistochemistry profile showed prominent PD-L1 expression, leading to additional interrogation on LPRM immunomorphological characteristics, the significance of the inflammatory tumoral microenvironment and its correlation with the immune-checkpoints

    Characterization of the NNVT capillary plate collimators

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    In this paper, we report the results of the characterization campaign of two prototypes of Micro-Channel Plates (MCPs), designed as the X-ray collimators for the Large Area Detector on board the eXTP mission. The devices were developed ad-hoc by North Night Vision Technology Co., Ltd. (Nanjing, China). Measurements involved the study of the angular response (rocking curve) of each device to X-rays of different energies. The study evidenced how the angular response of a collimator changes with the energy of the incoming photons, with the onset of side lobes at high energy, which enlarge the effective field of view of the device, causing a potential contamination of the on-axis signal. Nevertheless, the magnitude of this effect is proven to be acceptable in most situations of astrophysical interest. On the lower hand of the energy spectrum, photons may also modify the angular response due to grazing reflection on the inner walls of the collimator, a phenomenon strongly dependent on the degree of roughness of the surfaces involved. The whole campaign took place at the INAF/IAPS laboratories in Rome

    Sensitivity Projections for Dark Matter Searches with the Fermi Large Area Telescope

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    The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of the γ\gamma-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the bbˉb\bar{b} annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the bbˉb\bar{b} (τ+τ\tau^+ \tau^-) annihilation channels.Comment: Updated with a few additional and corrected references; otherwise, text is identical to previous version. Submitted on behalf of the Fermi-LAT collaboration. Accepted for publication in Physics Reports, 59 pages, 34 figures; corresponding author: Eric Charles ([email protected]

    PixDD: a multi-pixel silicon drift detector for high-throughput spectral-timing studies

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    The Pixelated silicon Drift Detector (PixDD) is a two-dimensional multi-pixel X-ray sensor based on the technology of Silicon Drift Detectors, designed to solve the dead time and pile-up issues of photon-integrating imaging detectors. Read out by a two-dimensional self-triggering Application-Specific Integrated Circuit named RIGEL, to which the sensor is bump-bonded, it operates in the 0:5 — 15 keV energy range and is designed to achieve single-photon sensitivity and good spectroscopic capabilities even at room temperature or with mild cooling (< 150 eV resolution at 6 keV at 0 °C). The paper reports on the design and performance tests of the 128-pixel prototype of the fully integrated system

    The large area detector onboard the eXTP mission

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    The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a flagship mission of the Chinese Academy of Sciences and the China National Space Administration, with a large European participation coordinated by Italy and Spain. The eXTP mission is currently performing its phase B study, with a target launch at the end-2027. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. The LAD instrument is based on the design originally proposed for the LOFT mission. It envisages a deployed 3.2 m2 effective area in the 2-30 keV energy range, achieved through the technology of the large-area Silicon Drift Detectors - offering a spectral resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators - limiting the field of view to about 1 degree. In this paper we will provide an overview of the LAD instrument design, its current status of development and anticipated performance

    The enhanced X-ray Timing and Polarimetry mission – eXTP: an update on its scientific cases, mission profile and development status

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    The enhanced X-ray Timing and Polarimetry mission (eXTP) is a flagship observatory for X-ray timing, spectroscopy and polarimetry developed by an International Consortium. Thanks to its very large collecting area, good spectral resolution and unprecedented polarimetry capabilities, eXTP will explore the properties of matter and the propagation of light in the most extreme conditions found in the Universe. eXTP will, in addition, be a powerful X-ray observatory. The mission will continuously monitor the X-ray sky, and will enable multiwavelength and multi-messenger studies. The mission is currently in phase B, which will be completed in the middle of 2022

    Posterior interosseous nerve entrapments: review of the literature. Is the entrapment distal to the arcade of Frohse a really rare condition?

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    Introduction: Spontaneous posterior interosseous nerve palsy is a rare condition. Entrapment is mostly at level of the arcade of Frohse, and a few cases of distal entrapment have been described. Methods: A case of entrapment distal to the arcade of Frohse is described here. Cases of distal entrapment have been reviewed from the published literature in order to evaluate the frequency of atraumatic mechanical palsy. Results: Seven cases of distal entrapment have been identified. Lesion is the cause of palsy in 58.7% of the cases and entrapment in 20.65%. The pathology is at the elbow in 33.7% of the cases, at the arcade of Frohse in 28.26%, and at the supinator canal in 10.33%. Entrapment is at the arcade of Frohse in 64.45%, proximal in 20%, and distal in 15.55%. Conclusion: Posterior interosseous nerve distal entrapment is a rare condition; therefore, further investigation is needed when radiological images at the arcade of Frohse do not show any entrapment

    Traumatic subarachnoid hemorrhage related to ophthalmic artery avulsion: a case report

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    We present a case of ophthalmic artery (OA) traumatic avulsion, leading to a post-traumatic subarachnoid hemorrhage (SAH) with ventricular blood invasion and hydrocephalus, mimicking an internal carotid aneurysm rupture. This is the third case of such an event reported in literature and the first without orbital fractures and optic nerve avulsion. Conservative treatment was sufficient for the avulsion, but surgery was needed for the coexisting eye luxation. Traumatic OA avulsion is a rare but possible event and should be suspected in case of basal cisterns SAH, evidence of orbital trauma and CT angiogram or angiographic absence of opacification of the OA

    Turning tables: a war-like approach to neurosurgical emergencies in the Covid-19

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    BACKGROUND: During the Coronavirus-disease-2019 (COVID-19) pandemic emergency, neurosurgeons may have to decide to prioritize treatments to patients with the best chance of survival, as in a war setting triage. We discuss factors that should be taken into account in the perioperative period and neurocritical care management of neurosurgical patients during a pandemic emergency; in particular, we will focus on the decision on whether to operate or not a patient during the COVID-19 pandemic and where and how to provide neurointensive care treatment.METHODS: A multidisciplinary expert panel composed by specialists with direct experience in COVID-19 management discussed and reviewed the criteria that should be taken into account in the decision to operate or not a patient during the COVID-19 pandemic.RESULTS: Disease-related factors should be first taken into account in order to precisely know the enemy we are facing. Patient-related factors should be then evaluated to understand the battleground on which we are facing the enemy. After these considerations, we must ascertain costs and expected outcomes of our surgical intervention by evaluation of surgery-related factors. Finally, the last factor that need to be evaluated before surgery is the availability of resources, staff and ward availability for perioperative care in particular. All these considerations will lead to the optimal organization and management of neurosurgical emergencies during pandemic times, taking into account the community and not only the single patient.CONCLUSIONS: We provided schematic preoperative considerations that we hope will help neurosurgeons to guide their decisions in these challenging times
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