13 research outputs found

    Enzyme-linked immunosorbent assay (ELISA) for measles antibody: a comparison with haemagglutination inhibition, immunofluorescence and plaque neutralization tests Reação imunoenzimática (ELISA) para detecção de anticorpos para o vírus do sarampo: comparação com reações de inibição da hema-glutinação, imunofluorescência indireta e neutralização de placas

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    An enzyme-linked immunosorbent assay (ELISA) for measles antibodies was compared with Plaque Neutralization (PRN), Haemagglutination inhibition (HI) and Fluorescent antibody (IFA) tests in 181 sera from vaccinated children and umbilical cord. Of 179 positive samples by the sensitive PRN, only two, with titers of 8, were negative by ELISA (copositivity of 98.9%). IFA and HI presented, respectively, copo-sitivities of 93.3% and 82.7%. The ELISA presented a high sensitivity as well as a good reproducibility and represents an alternative for the time consuming PRN for detection of low measles antibodies.<br>A reação imunoenzimática (ELISA) para determinação de anticorpos para o vírus do sarampo foi comparada com a reação de neutralização de placas (RNP), inibição da hemaglutinação (RIH) e imunofluorescência indireta (RIF). Das 179 amostras positivas pela RNP, somente 2, com títulos iguais a 8, se apresentaram negativas por ELISA (copositividade de 98.9%). A RIF e RIH apresentaram, respectivamente, copositividade de 93.3 e 82.7%. ELISA apresentou sensibilidade equivalente à complexa RNP, boa reprodutibilidade e representa uma alternativa para a detecção de baixos títulos de anticorpos contra o sarampo

    Calibration and Characterization of the Radiation Assessment Detector (RAD) on Curiosity

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    The Radiation Assessment Detector, RAD, is one of the ten instruments that make up the science payload of the Mars Science Laboratory Curiosity rover. RAD is an energetic particle detector, capable of measuring the charged and neutral particles that make significant contributions to the radiation dose that will be received by future human explorers when they visit Mars. Prior to the launch of MSL in November 2011, RAD and its nearidentical twin flight spare unit were calibrated using laboratory sources, charged particle beams, and neutron fields. The initial calibration parameters obtained in these tests were used for real-time data analysis by the instrument’s onboard software. These parameters have subsequently been refined using data obtained during the cruise to Mars and during Curiosity’s mission on the surface of Mars. The most critical use of calibration is in the dosimetry analysis performed onboard. Calibration is also used in onboard analysis to determine which events should be stored for telemetry to Earth. Accelerator data obtained with the flight spare unit after Curiosity was launched provide detailed information about the response of the organic and inorganic scintillators to ion beams over a wide range of charge and energy. Here we report on the methods used to determine calibration parameters, the results obtained, as well as providing an overview of the modifications to the instrument’s software and configuration that have been made over the course of the mission
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