179 research outputs found

    Wireless aquatic navigator for detection and analysis (WANDA)

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    The cost of monitoring and detecting pollutants in natural waters is of major concern. Current and forthcoming bodies of legislation will continue to drive demand for spatial and selective monitoring of our environment, as the focus increasingly moves towards effective enforcement of legislation through detection of events, and unambiguous identification of perpetrators. However, these monitoring demands are not being met due to the infrastructure and maintenance costs of conventional sensing models. Advanced autonomous platforms capable of performing complex analytical measurements at remote locations still require individual power, wireless communication, processor and electronic transducer units, along with regular maintenance visits. Hence the cost base for these systems is prohibitively high, and the spatial density and frequency of measurements are insufficient to meet requirements. In this paper we present a more cost effective approach for water quality monitoring using a low cost mobile sensing/communications platform together with very low cost stand-alone ‘satellite’ indicator stations that have an integrated colorimetric sensing material. The mobile platform is equipped with a wireless video camera that is used to interrogate each station to harvest information about the water quality. In simulation experiments, the first cycle of measurements is carried out to identify a ‘normal’ condition followed by a second cycle during which the platform successfully detected and communicated the presence of a chemical contaminant that had been localised at one of the satellite stations

    249 TP53 mutation has high prevalence and is correlated with larger and poorly differentiated HCC in Brazilian patients

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    <p>Abstract</p> <p>Background</p> <p>Ser-249 TP53 mutation (249<sup>Ser</sup>) is a molecular evidence for aflatoxin-related carcinogenesis in Hepatocellular Carcinoma (HCC) and it is frequent in some African and Asian regions, but it is unusual in Western countries. HBV has been claimed to add a synergic effect on genesis of this particular mutation with aflatoxin. The aim of this study was to investigate the frequency of 249<sup>Ser </sup>mutation in HCC from patients in Brazil.</p> <p>Methods</p> <p>We studied 74 HCC formalin fixed paraffin blocks samples of patients whom underwent surgical resection in Brazil. 249<sup>Ser </sup>mutation was analyzed by RFLP and DNA sequencing. HBV DNA presence was determined by Real-Time PCR.</p> <p>Results</p> <p>249<sup>Ser </sup>mutation was found in 21/74 (28%) samples while HBV DNA was detected in 13/74 (16%). 249<sup>Ser </sup>mutation was detected in 21/74 samples by RFLP assay, of which 14 were confirmed by 249<sup>Ser </sup>mutant-specific PCR, and 12 by nucleic acid sequencing. All HCC cases with p53-249ser mutation displayed also wild-type p53 sequences. Poorly differentiated HCC was more likely to have 249<sup>Ser </sup>mutation (OR = 2.415, 95% CI = 1.001 – 5.824, p = 0.05). The mean size of 249<sup>Ser </sup>HCC tumor was 9.4 cm versus 5.5 cm on wild type HCC (p = 0.012). HBV DNA detection was not related to 249<sup>Ser </sup>mutation.</p> <p>Conclusion</p> <p>Our results indicate that 249<sup>Ser </sup>mutation is a HCC important factor of carcinogenesis in Brazil and it is associated to large and poorly differentiated tumors.</p

    Polymer actuators

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    A Microfabricated Movable Electrochromic “Pixel” Based on Polypyrrole

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    A Microfabricated Movable Electrochromic “Pixel” Based on Polypyrrole

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