167 research outputs found

    Clonal Complex 258, the Most Frequently Found Multilocus Sequence Type Complex in KPC-2-Producing Klebsiella pneumoniae Isolated in Brazilian Hospitals

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    Universidade Federal de São Paulo, Lab Alerta, Div Infect Dis, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo, Cent Lab, Hosp São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Lab Alerta, Div Infect Dis, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo, Cent Lab, Hosp São Paulo, São Paulo, BrazilWeb of Scienc

    Unusual association of NDM-1 with KPC-2 and armA among Brazilian Enterobacteriaceae isolates

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    We report the microbiological characterization of four New Delhi metallo-beta-lactamase-1 (bla(NDM-1))-producing Enterobacteriaceae isolated in Rio de Janeiro, Brazil. bla(NDM-1) was located on a conjugative plasmid and was associated with Klebsiella pneumoniae carbapenemase-2 (bla(KPC-2)) or aminoglycoside-resistance methylase ( armA), a 16S rRNA methylase not previously reported in Brazil, in two distinct strains of Enterobacter cloacae. Our results suggested that the introduction of bla(NDM-1) in Brazil has been accompanied by rapid spread, since our isolates showed no genetic relationship.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Med, Lab Especial Microbiol Clin, São Paulo, SP, BrazilDASA, Lab Diagnost Amer, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Med, Lab Especial Microbiol Clin, São Paulo, SP, BrazilWeb of Scienc

    TSIL: a program for the calculation of two-loop self-energy integrals

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    TSIL is a library of utilities for the numerical calculation of dimensionally regularized two-loop self-energy integrals. A convenient basis for these functions is given by the integrals obtained at the end of O.V. Tarasov's recurrence relation algorithm. The program computes the values of all of these basis functions, for arbitrary input masses and external momentum. When analytical expressions in terms of polylogarithms are available, they are used. Otherwise, the evaluation proceeds by a Runge-Kutta integration of the coupled first-order differential equations for the basis integrals, using the external momentum invariant as the independent variable. The starting point of the integration is provided by known analytic expressions at (or near) zero external momentum. The code is written in C, and may be linked from C, C++, or Fortran. A Fortran interface is provided. We describe the structure and usage of the program, and provide a simple example application. We also compute two new cases analytically, and compare all of our notations and conventions for the two-loop self-energy integrals to those used by several other groups.Comment: 31 pages. Updated to reflect new functionality through v1.4 May 2016 and new information about use with C++. Source code and documentation are available at http://www.niu.edu/spmartin/TSIL or http://faculty.otterbein.edu/DRobertson/tsil

    Intraclonal Genome Stability of the Metallo-beta-lactamase SPM-1-producing Pseudomonas aeruginosa ST277, an Endemic Clone Disseminated in Brazilian Hospitals

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    Carbapenems represent the mainstay therapy for the treatment of serious P aeruginosa infections. However, the emergence of carbapenem resistance has jeopardized the clinical use of this important class of compounds. The production of SPM-1 metallo-beta-lactamase has been the most common mechanism of carbapenem resistance identified in P. aeruginosa isolated from Brazilian medical centers. Interestingly, a single SPM-1-producing P. aeruginosa clone belonging to the ST277 has been widely spread within the Brazilian territory. In the current study, we performed a next-generation sequencing of six SPM-1-producing P. aeruginosa ST277 isolates. The core genome contains 5899 coding genes relative to the reference strain P. aeruginosa PAO1. A total of 26 genomic islands were detected in these isolates. We identified remarkable elements inside these genomic islands, such as copies of the bla(spM-1) gene conferring resistance to carbapenems and a type I-C CRISPR-Cas system, which is involved in protection of the chromosome against foreign DNA. In addition, we identified single nucleotide polymorphisms causing amino acid changes in antimicrobial resistance and virulence-related genes. Together,these factors could contribute to the marked resistance and persistence of the SPM-1-producing P aeruginosa ST277 clone. A comparison of the SPM-1-producing P. aeruginosa ST277 genomes showed that their core genome has a high level nucleotide similarity and synteny conservation. The variability observed was mainly due to acquisition of genomic islands carrying several antibiotic resistance genes.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Lab Nacl Comp Cient, Lab Bioinformat, Petropolis, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Internal Med, Lab Alerta,Div Infect Dis, Sao Paulo, BrazilLaboratório Alerta, Division of Infectious Diseases, Department of Internal Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, BrazilCNPq: 305535/2014-5CNPq: 302768/2011-4CNPq: 312864/2015-9FAPERJ: E-26/202.903/2016Web of Scienc

    The influence of tumor- and treatment-related factors on the development of local recurrence in osteosarcoma after adequate surgery. An analysis of 1355 patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols

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    Background: Local recurrence (LR) in osteosarcoma is associated with very poor prognosis. We sought to evaluate which factors correlate with LR in patients who achieved complete surgical remission with adequate margins. Patients and methods: We analyzed 1355 patients with previously untreated high-grade central osteosarcoma of the extremities, the shoulder and the pelvis registered in neoadjuvant Cooperative Osteosarcoma Study Group trials between 1986 and 2005. Seventy-six patients developed LR. Results: Median follow-up was 5.56 years. No participation in a study, pelvic tumor site, limb-sparing surgery, soft tissue infiltration beyond the periosteum, poor response to neoadjuvant chemotherapy, failure to complete the planned chemotherapy protocol and biopsy at a center other than the one performing the tumor resection were significantly associated with a higher LR rate. No differences were found for varying surgical margin widths. Surgical treatment at centers with small patient volume and additional surgery in the primary tumor area, other than biopsy and tumor resection, were significantly associated with a higher rate of ablative surgery. Conclusions: Patient enrollment in clinical trials and performing the biopsy at experienced institutions capable of undertaking the tumor resection without compromising the oncological and functional outcome should be pursued in the futur

    Design and construction of the MicroBooNE Cosmic Ray Tagger system

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    The MicroBooNE detector utilizes a liquid argon time projection chamber (LArTPC) with an 85 t active mass to study neutrino interactions along the Booster Neutrino Beam (BNB) at Fermilab. With a deployment location near ground level, the detector records many cosmic muon tracks in each beam-related detector trigger that can be misidentified as signals of interest. To reduce these cosmogenic backgrounds, we have designed and constructed a TPC-external Cosmic Ray Tagger (CRT). This sub-system was developed by the Laboratory for High Energy Physics (LHEP), Albert Einstein center for fundamental physics, University of Bern. The system utilizes plastic scintillation modules to provide precise time and position information for TPC-traversing particles. Successful matching of TPC tracks and CRT data will allow us to reduce cosmogenic background and better characterize the light collection system and LArTPC data using cosmic muons. In this paper we describe the design and installation of the MicroBooNE CRT system and provide an overview of a series of tests done to verify the proper operation of the system and its components during installation, commissioning, and physics data-taking

    Ionization Electron Signal Processing in Single Phase LArTPCs II. Data/Simulation Comparison and Performance in MicroBooNE

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    The single-phase liquid argon time projection chamber (LArTPC) provides a large amount of detailed information in the form of fine-grained drifted ionization charge from particle traces. To fully utilize this information, the deposited charge must be accurately extracted from the raw digitized waveforms via a robust signal processing chain. Enabled by the ultra-low noise levels associated with cryogenic electronics in the MicroBooNE detector, the precise extraction of ionization charge from the induction wire planes in a single-phase LArTPC is qualitatively demonstrated on MicroBooNE data with event display images, and quantitatively demonstrated via waveform-level and track-level metrics. Improved performance of induction plane calorimetry is demonstrated through the agreement of extracted ionization charge measurements across different wire planes for various event topologies. In addition to the comprehensive waveform-level comparison of data and simulation, a calibration of the cryogenic electronics response is presented and solutions to various MicroBooNE-specific TPC issues are discussed. This work presents an important improvement in LArTPC signal processing, the foundation of reconstruction and therefore physics analyses in MicroBooNE.Comment: 54 pages, 36 figures; the first part of this work can be found at arXiv:1802.0870

    A Deep Neural Network for Pixel-Level Electromagnetic Particle Identification in the MicroBooNE Liquid Argon Time Projection Chamber

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    We have developed a convolutional neural network (CNN) that can make a pixel-level prediction of objects in image data recorded by a liquid argon time projection chamber (LArTPC) for the first time. We describe the network design, training techniques, and software tools developed to train this network. The goal of this work is to develop a complete deep neural network based data reconstruction chain for the MicroBooNE detector. We show the first demonstration of a network's validity on real LArTPC data using MicroBooNE collection plane images. The demonstration is performed for stopping muon and a νμ\nu_\mu charged current neutral pion data samples

    Ionization Electron Signal Processing in Single Phase LArTPCs I. Algorithm Description and Quantitative Evaluation with MicroBooNE Simulation

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    We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection anode wire planes will augment the 3D reconstruction, and is particularly important for tomographic reconstruction algorithms. A number of building blocks of the overall procedure are described. The performance of the signal processing is quantitatively evaluated by comparing extracted charge with the true charge through a detailed TPC detector simulation taking into account position-dependent induced current inside a single wire region and across multiple wires. Some areas for further improvement of the performance of the charge extraction procedure are also discussed.Comment: 60 pages, 36 figures. The second part of this work can be found at arXiv:1804.0258
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