1,339 research outputs found

    Photosensor test station for theMu2e electromagnetic calorimeter

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    The Mu2e experiment searches for coherent, neutrinoless conversion of muons into electrons in the field of a nucleus. The Mu2e measurement will have a sensitivity of fews parts in 10−17, with an improvement of a factor of 103–104 with respect to the existing limits. The Mu2e apparatus takes advantage of the high intensity muon beam which hits muon stopping targets, and uses a detector composed of a low-mass straw tubes tracker and an electromagnetic calorimeter. The calorimeter is made of 1860 hexagonal crystals read out by two large area photosensors, for a total of 3720 channels. Two options of photosensors are currently under study: large-area Avalanche Photo Diodes (APDs) and Silicon Photo Multipliers (SiPMs). A photosensor test station has been developed in Pisa, in collaboration with the LNF Mu2e group, in order to validate the photosensors performance. In particular the following characteristics are carefully studied: gain vs. bias voltage, gain vs. temperature, gain vs. light source position and dark current characterization

    The Mu2e experiment at Fermilab: μ N→ e N

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    Lepton flavor violation in the neutrino mixing is so far a fact. This means that also charged-lepton-flavor-violation (cLFV) must exists. Mu2e searches for a particular process, the neutrino-less conversion of muons into electrons in the field of an aluminum nucleus. The sensitivity expected for Mu2eis ∼ 10−17, which represents an improvement of a factor of 103-104 over existing limits. If no conversion events will be seen, it will set an upper limit on the conversion rate of Rμe < 6 × 10−17 90% C.L. Mu2e collaboration has received CD1 approval in 2012 and will start data taking in 2019

    Components Qualification for a Possible use in the Mu2e Calorimeter Waveform Digitizers

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    The Mu2e experiment at Fermilab searches for the charged flavor violating conversion of a muon into an electron in the Coulomb field of a nucleus. The detector consists of a straw tube tracker and a CSI crystal electromagnetic calorimeter, both housed in a superconducting solenoid. Both the front-end and the digital electronics, located inside the cryostat, will be operated in vacuum under a 1 T magnetic field, having to sustain the high flux of neutrons and ionizing particles coming from the muons stopping target. These harsh experimental conditions make the design of the calorimeter waveform digitizer quite challenging. All the selected commercial devices must be tested individually and qualified for radiation hardness and operation in high magnetic field. At the moment the expected particles flux and spectra at the digitizers location are not completely simulated and we are using initial rough estimates to select the components for the first prototype. We are gaining experience in the qualification procedures using the selected components but the choice will be frozen only when dose and neutron flux simulations will be completed. The experimental results of the first qualification campaign are presented.Comment: TWEPP 2016 - Topical Workshop on Electronics for Particle Physics, 26-30 September 2016, Karlsruhe Institute of Technology (KIT

    A decrease of calcitonin serum concentrations less than 50 percent 30 minutes after thyroid surgery suggests incomplete C-cell tumor tissue removal

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    The prognosis of medullary thyroid carcinoma (MTC) depends on the completeness of the first surgical treatment. To date, it is not possible to predict whether the tumor has been completely removed after surgery. The aim of this study was to evaluate the reliability of an intraoperative calcitonin monitoring as a predictor of the final outcome after surgery in patients with MTC

    Liver nodular regenerative hyperplasia after bone marrow transplant.

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    We report an unusual liver disease which may occur after bone marrow transplantation, i.e. the collapse of hepatic lobuli followed by regenerative islets: the resulting clinical picture may mimic GvHD or a viral disease, but histology is diagnostic, showing nodular regeneration in the absence of inflammation or fibrosis

    Post-transplant cerebral toxoplasmosis diagnosed by magnetic resonance imaging.

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    Cerebral toxoplasmosis is a rare late complication in allogeneic bone marrow transplanted patients. Neuroradiological findings may suggest the correct diagnosis. We report a patient in whom cerebral magnetic resonance imaging (MRI) showed a lesion characteristic of toxoplasmosis. Anti- toxoplasma treatment led to clinical and radiological improvement. MRI seems to be a valid tool for detection and follow-up of cerebral toxoplasmosis

    Low-dose interleukin-2 for treating postautologous transplant cytogenetic abnormality recurrency in a case of acute myeloid leukemia with hyperdiploidy.

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    Adoptive immunotherapy and/or immunostimulation may be effective in treating early phases of leukemia relapsing after allogeneic transplant. Donor lymphocyte infusion (DLI) is an established treatment for cytogenetic relapse of chronic myeloid leukemia (CML) after unmanipulated or T-cell–depleted bone marrow transplant (BMT)1; favorable results have also been reported in a few cases of initial posttransplant relapse of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).2 A graft-versus-leukemia (GVL) effect as part of a manifest or occult DLI-elicited graft-versus-host disease (GVHD) is thought to be the reason for these favorable results. For patients who had received autologous transplant, attempts to elicit an antineoplastic effect by immunostimulation have been made using in vitro interleukin-2 (IL-2)–activated autologous lymphocytes and/or IL-2 in vivo administration.34 We report on the successful use of subcutaneous (sc) low-dose IL-2 in a patient suffering from AML with recurrence of cytogenetic abnormalities after autografting

    CD34+ enriched donor lymphocyte infusions in a case of pure red cell aplasia and late graft failure after major ABO-incompatible bone marrow transplantation

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    A variety of immunohematological complications may occur after ABO-incompatible BMT. We report a CML patient (blood group O) who received a BMT from an HLA-identical sibling (blood group AB). The transplant was followed by normal myeloid and megakaryocytic engraftment, but erythroblastopenia persisted for more than 200 days after BMT. By bone marrow culture studies, a complement-dependent serum inhibitor of hemopoiesis was detected, suggesting immunological inhibition of erythropoiesis. The patient was resistant to a number of treatments such as intravenous gamma-globulins, prednisolone and high-dose erythropoietin. Full engraftment with normal blood counts and marrow cellularity was achieved after two dose-escalating CD34+-enriched donor lymphocyte infusions (DLI). This experience suggests that CD34+-enriched DLI may be an effective treatment for patients with delayed engraftment or late graft failure due to major ABO-incompatibility
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