3,414 research outputs found

    Ultrasound-guided hook-wire localization for surgical excision of non-palpable superficial inguinal lymph nodes in dogs: A pilot study

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    The evaluation of loco-regional lymph nodes (LN) plays an important prognostic role and assists the clinical decision making in canine cancer patients. Excision of non-palpable LN can be challenging. The aim of the study was to evaluate surgical time, successful excision rate and surgical complications associated with the use of an ultrasound-guided hook-wire (UGHW) LN localization method for non-palpable superficial inguinal LN (SILN) in dogs. Dogs that presented for excision of non-palpable SILN, performed with the aid of an UGHW placement, were enrolled. Information including signalment, SILN width, UGHW placement and surgical procedure time, hook-wire position, successful excision and intra-and post-operative complications were reviewed. Seventeen dogs were enrolled. Median LN width was 3 mm (range 2–11). Median time of preoperative UGHW placement and surgical LN excision was 8 min and 15 min, respectively. Successful SILN excision was achieved in all cases. Two minor intra-operative (hook migration and wire fragmentation) and one minor post-operative complications (seroma) were observed. No major intraoperative or post-operative complications occurred. The UGHW LN localization method is safe and effective and may allow a high rate of successful SILN excisions in dogs. This method has the potential to facilitate LN excision for other superficial LN locations

    The CMS Micro-strip Gas Chamber Project: Development of a high resolution tracking detector for harsh radiation environments

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    Thirty-two large area Micro-Strip Gas Chambers were tested in a high intensity, 350~MeV pion beam at PSI to prove that we had reached a Milestone for the Compact Muon Solenoid (CMS) experiment. The particle rate was approximately 6 kHz/mm2, distributed over the whole active area of the detectors, and this rate was maintained for a total integrated time of 493 hours. All of the chambers were operated with signal-to-noise values at or above that corresponding to 98 % hit detection efficiency at CMS; the average S/N was 31. No indications of any gain instabilities or ageing effects were observed. In the official 3-week Milestone period, three strips from a total of 16384 were damaged, a result which is twenty times lower than the minimal requirement for CMS. The spark rate of the detectors was very low and decreased with time to an average of one spark per chamber per day. The cathode voltages of 24 of the chambers were increased over a one week period to investigate the behaviour of the detectors at higher gains; the maximum S/N value was 2.4 times that at the normal working point. No significant increase in spark rate or strip loss rate was detected and the chambers operated stably. The detector efficiencies and imaging capabilities were also investigated. The MSGC design features and the assembly and test methodologies that enabled us to achieve these results are reported

    Genome sequence analysis of the first human West Nile virus isolated in Italy in 2009.

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    In 2009, six new human cases of West Nile neuroinvasive disease (WNND) were identified in Veneto region, following the six cases already reported in 2008. A human West Nile virus (WNV) isolate was obtained for the first time from an asymptomatic blood donor. Whole genome sequence of the human WNV isolate showed close phylogenetic relatedness to the Italy-1998-WNV strain and to other WNV strains recently isolated in Europe, with the new acquisition of the NS3-Thr249Pro mutation, a trait associated with avian virulence, increased virus transmission, and the occurrence of outbreaks in humans

    prevalence of igm and igg antibodies to west nile virus among blood donors in an affected area of north eastern italy summer 2009

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    Following reports of West Nile neuroinvasive disease in the north-eastern area of Italy in 2009, all blood donations dating from the period between 1 August and 31 October 2009 in the Rovigo province of the Veneto region were routinely checked to exclude those with a positive nucleic acid test for West Nile virus (WNV). Only one of 5,726 blood donations was positive (17.5 per 100,000 donations; 95% confidence interval (CI): 0.4-97.3). In addition, a selection of 2,507 blood donations collected during the period from 20 July to 15 November 2009 were screened by ELISA for IgG and IgM antibodies against WNV. A positive result was received for 94 of them. The positive sera were further evaluated using immunofluorescence and plaque reduction neutralisation test (PRNT), in which only 17 sera were confirmed positive. This corresponds to a prevalence of 6.8 per 1,000 sera (95% CI: 4.0-10.9). In a case-control study that matched each of the 17 PRNT-positive sera with four negative sera with the same date of donation and same donation centre, we did not find a significant association with age and sex of the donor; donors who worked mainly outdoors were significantly more at risk to have a positive PRNT for WNV

    Human cases of West Nile Virus infection in north-eastern Italy, 15 June to 15 November 2010.

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    In 2010, for the third consecutive year, human cases of West Nile virus (WNV) infection, including three confirmed cases of neuroinvasive disease and three confirmed cases of West Nile fever, were identified in north-eastern Italy. While in 2008 and 2009 all human cases of WNV disease were recorded in the south of the Veneto region, cases of WNV disease in 2010 additionally occurred in two relatively small northern areas of Veneto, located outside those with WNV circulation in the previous years. WNV IgG antibody prevalence in blood donors resident in Veneto was estimated as ranging from 3.2 per 1,000 in areas not affected by cases of WNV disease to 33.3 per 1,000 in a highly affected area of the Rovigo province. No further autochthonous human cases of WNV disease were notified in Italy in 2010. The recurrence of human cases of WNV infection for the third consecutive year strongly suggests WNV has become endemic in north-eastern Italy

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

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    Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model
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