105 research outputs found

    Teste rápido de aglutinação utilizando partículas de látex para a detecção de anticorpos anti-cisticercos em amostras de líquido cefalorraquidiano (LCR)

    Get PDF
    Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.Testes diagnósticos simples e rápidos baseados na aglutinação de partículas de látex têm sido utilizados para a pequisa de antígenos ou anticorpos específicos em muitas doenças. No presente trabalho, é descrito um teste de aglutinação em lâmina para a pesquisa de anticorpos contra cisticercos de Taenia solium, utilizando partículas de látex revestidas com um extrato bruto do parasita. Anticorpos anti-cisticercos foram pesquisados em 19 amostras de LCR de pacientes com neurocisticercose e em 24 amostras de LCR de pacientes com outros problemas neurológicos (neurosífilis, n = 8; neurotoxoplasmose, n = 3; meningite viral, n = 4; cefaléia crônica, n = 9). O teste de aglutinação apresentou sensibilidade e especificidade de 89,5% e 75%, respectivamente. O teste de aglutinação para cisticercose idealizado é simples, rápido e barato. Essas características tornam o teste um meio promissor de expansão e simplificação do imunodiagnósico da neurocisticercose. Estudos futuros poderiam testar a sensibilização das partículas de látex com antígenos de cisticercos purificados e a pesquisa de anticorpos em amostras de soros

    Teste rápido de aglutinação utilizando partículas de látex para a detecção de anticorpos anti-cisticercos em amostras de líquido cefalorraquidiano (LCR)

    Get PDF
    Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.Testes diagnósticos simples e rápidos baseados na aglutinação de partículas de látex têm sido utilizados para a pequisa de antígenos ou anticorpos específicos em muitas doenças. No presente trabalho, é descrito um teste de aglutinação em lâmina para a pesquisa de anticorpos contra cisticercos de Taenia solium, utilizando partículas de látex revestidas com um extrato bruto do parasita. Anticorpos anti-cisticercos foram pesquisados em 19 amostras de LCR de pacientes com neurocisticercose e em 24 amostras de LCR de pacientes com outros problemas neurológicos (neurosífilis, n = 8; neurotoxoplasmose, n = 3; meningite viral, n = 4; cefaléia crônica, n = 9). O teste de aglutinação apresentou sensibilidade e especificidade de 89,5% e 75%, respectivamente. O teste de aglutinação para cisticercose idealizado é simples, rápido e barato. Essas características tornam o teste um meio promissor de expansão e simplificação do imunodiagnósico da neurocisticercose. Estudos futuros poderiam testar a sensibilização das partículas de látex com antígenos de cisticercos purificados e a pesquisa de anticorpos em amostras de soros.575

    Dimensionless cosmology

    Full text link
    Although it is well known that any consideration of the variations of fundamental constants should be restricted to their dimensionless combinations, the literature on variations of the gravitational constant GG is entirely dimensionful. To illustrate applications of this to cosmology, we explicitly give a dimensionless version of the parameters of the standard cosmological model, and describe the physics of Big Bang Neucleosynthesis and recombination in a dimensionless manner. The issue that appears to have been missed in many studies is that in cosmology the strength of gravity is bound up in the cosmological equations, and the epoch at which we live is a crucial part of the model. We argue that it is useful to consider the hypothetical situation of communicating with another civilization (with entirely different units), comparing only dimensionless constants, in order to decide if we live in a Universe governed by precisely the same physical laws. In this thought experiment, we would also have to compare epochs, which can be defined by giving the value of any {\it one} of the evolving cosmological parameters. By setting things up carefully in this way one can avoid inconsistent results when considering variable constants, caused by effectively fixing more than one parameter today. We show examples of this effect by considering microwave background anisotropies, being careful to maintain dimensionlessness throughout. We present Fisher matrix calculations to estimate how well the fine structure constants for electromagnetism and gravity can be determined with future microwave background experiments. We highlight how one can be misled by simply adding GG to the usual cosmological parameter set

    Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

    Get PDF
    The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388

    Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

    Get PDF
    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at sNN\sqrt{s_{_{\rm NN}}} = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in η<0.8|\eta|<0.8 and 0.3<pT<200.3 < p_T < 20 GeV/cc are compared to the expectation in pp collisions at the same sNN\sqrt{s_{\rm NN}}, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAAR_{\rm AA}. The result indicates only weak medium effects (RAAR_{\rm AA} \approx 0.7) in peripheral collisions. In central collisions, RAAR_{\rm AA} reaches a minimum of about 0.14 at pT=6p_{\rm T}=6-7GeV/cc and increases significantly at larger pTp_{\rm T}. The measured suppression of high-pTp_{\rm T} particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

    Get PDF
    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
    corecore