737 research outputs found
Difficult patients or difficult encounters?
Universidade Federal de São Paulo, Dept Psychiat, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychiat, São Paulo, BrazilWeb of Scienc
Molecular Evaluation of exons 8 and 22 of the SHANK3 gene in Autism Spectrum Disorders
Autism spectrum disorders are a group of neurodevelopmental disorders with a complex and heterogeneous etiology. Studies have shown that genetic factors play an important role in the aetiology of these diseases. Recently, de novo mutations, frameshifts and deletions have been described in the SHANK3 gene, also known as ProSAP2 gene, which encodes a synaptic scaffolding protein. All the participants of this study had normal karyotypes and underwent screening for Fragile-X syndrome. Subsequently, they were analyzed by direct sequencing of different points of exons 8 and 22 of the SHANK3 gene. None of the study participants presented with changes in these regions. These findings may be due to the fact that mutations, deletions and duplications of the SHANK3 gene are rare
Towards implementation of a benthic microbial fuel cell in lake Furnas (Azores) : phylogenetic affiliation and electrochemical activity of sediment bacteria
This work was conducted to examine the composition and electrochemical activity of the bacterial community inhabiting lake Furnas sediments (Azores). Fingerprinting analysis of the bacterial 16S rRNA gene fragment was done by denaturing gradient gel electrophoresis. The sequences retrieved from lake Furnas sediments were affiliated to Bacteroidetes/Chlorobi group, Chloroflexi, Alfa-, Delta-, and Gamma-subclasses of Proteobacteria, Cyanobacteria, and Gemmatimonadetes. A cyclic voltammetric study was carried out with an enriched sediment bacterial suspension in a standard two chamber electrochemical cell using a carbon paper anode. Cyclic voltammograms (scan rate of 50 mV/s) showed the occurrence of oxidation–reduction reactions at the carbon anode surface. The benthic microbial fuel cell operated with lake Furnas sediments presented a low power density (1 mW/m2) indicating that further work is required to optimise its power generation. These results suggested that sediment bacteria, probably from the Delta- and Gamma-subclasses of Proteobacteria, were electroactive under tested conditions.Fundação para a Ciência e a Tecnologia (FCT) - bolsa SFRH/BD/25639/2005, SFRH/BD/38331/2007Regional Department of Water Resources and Land Planning, Geosciences Department, University of Azores; Foundation for Science and Technology/F.C.T., PortugalUniversity Azore
Células de combustÃvel microbianas : um processo inovador para produção de energia e tratamento de águas residuais em sistemas descentralizados
A produção de energia constitui uma base essencial para o desenvolvimento humano. Neste quadro, a capacidade de determinados microrganismos oxidarem matéria orgânica e transferirem eletrões para um ânodo e, por essa via, permitirem a produção direta de eletricidade representa uma efetiva oportunidade tecnológica. Este novo processo, designado por célula de combustÃvel microbiana, constitui uma abordagem de produção de energia elétrica com
capacidade para ser acoplada ao tratamento de águas residuais, apresentando elevado potencial para integrar fluxos de eletricidade e tratamento de águas residuais em sistemas descentralizados. No presente trabalho efetuaram-se ensaios eletroquÃmicos de voltametria cÃclica, os quais permitiram reforçar a importância da transferência direta de eletrões e da formação de biofilme eletroactivo na superfÃcie do eléctrodo. O desempenho da MFC para produção de bioeletricidade e tratamento de águas residuais foi efectuado com comunidades microbianas anódicas mista e pura (Geobacter sulfurreducens). As densidades de potência instantânea atingiram máximos de 710 W/m3 com uma cultura pura e 823 W/m3 com a mista, sendo que a remoção de carbono da água residual atingiu
valores médios de 83%
Impact of an external electron acceptor on phosphorus mobility between water and sediments
The present work assessed the impact of an external electron acceptor on phosphorus fluxes between water-sediment interface. Microcosm experiments simulating a sediment microbial fuel cell (SMFC) were carried out and phosphorus was extracted by an optimized combination of three methods. Despite the low voltage recorded, ∼96 mV (SMFC with carbon paper anode) and ∼146 mV (SMFC with stainless steel scourer anode), corresponding to a power density of 1.15 mW/m2 and 0.13 mW/m2, it was enough to produce an increase in the amounts of metal bound phosphorus (14% vs 11%), Ca-bound phosphorus (26% vs 23%) and refractory phosphorus (33% vs 28%). These results indicate an important role of electroactive bacteria in the phosphorus cycling and open a new perspective for preventing metal bound phosphorus dissolution from sediments.The authors are indebted and grateful to the Regional Department of Water Resources and Land Planning (Azores) and its staff. The authors also acknowledge the Grant SFRH/BPD/8052812011 from the Foundation for Science and Technology, Portugal, awarded to Gilberto Martins
Brain Abcess due to Cladophialophora bantiana: first case in Portugal
Clinical case reporting a brain abscess caused by Cladophialophora bantiana in an male patient with 56 years old. This is a rare case of a brain abscess caused by this species. Few cases have been reported in the literature world-wide, being this one the first reported in Portugal. The fungal isoltate was identified by morphological and molecular methods. After 16 months of the first brain abscess excision and after 5 months under therapy with voriconazol, the patient improved clinical and imagiologicaly, maintaining only minimal neurological deficits
Dendrimer Stabilized Nanoalloys for Ink-Jet Printing of Surface-Enhanced Raman Scattering Substrates
Research on paper substrates prepared by inkjet deposition of metal nanoparticles for sensing applications has become a hot topic in recent years; however, the design of such substrates based on the deposition of alloy nanoparticles remains less explored. Herein, we report for the first time the inkjet printing of dendrimer-stabilized colloidal metal nanoalloys for the preparation of paper substrates for surface-enhanced Raman scattering (SERS) spectroscopy. To this end, nanoassemblies containing variable molar ratios of Au:Ag were prepared in the presence of poly(amidoamine) dendrimer (PAMAM), resulting in plasmonic properties that depend on the chemical composition of the final materials. The dendrimer-stabilized Au:Ag:PAMAM colloids exhibit high colloidal stability, making them suitable for the preparation of inks for long-term use in inkjet printing of paper substrates. Moreover, the pre-treatment of paper with a polystyrene (PS) aqueous emulsion resulted in hydrophobic substrates with improved SERS sensitivity, as illustrated in the analytical detection of tetramethylthiuram disulfide (thiram pesticide) dissolved in aqueous solutions. We suggest that the interactions established between the two polymers (PAMAM and PS) in an interface region over the cellulosic fibres, resulted in more exposed metallic surfaces for the adsorption of the analyte molecules. The resulting hydrophobic substrates show long-term plasmonic stability with high SERS signal retention for at least ninety days.publishe
Assessing the performance of a plastic optical fibre turbidity sensor for measuring post-fire erosion from plot to catchment scale
This study is the first comprehensive testing of a novel plastic optical fibre turbidity sensor with runoff samples collected in the field and, more specifically, with a total of 158 streamflow samples and 925 overland flow samples from a recently burnt forest area in north-central Portugal, collected mainly during the first year after the wildfire, as well as with 56 overland flow samples from a nearby long-unburnt study site. Sediment concentrations differed less between overland flow and streamflow samples than between study sites and, at one study site, between plots with and without effective erosion mitigation treatments. Maximum concentrations ranged from 0.91 to 8.19 g L−1 for the micro-plot overland flow samples from the six burnt sites, from 1.74 to 8.99 g L−1 for the slope-scale overland flow samples from these same sites, and amounted to 4.55 g L−1 for the streamflow samples. Power functions provided (reasonably) good fits to the – expected – relationships of increasing normalized light loss with increasing sediment concentrations for the different sample types from individual study sites. The corresponding adjusted R2 values ranged from 0.64 to 0.81 in the case of the micro-plot samples from the six burnt sites, from 0.72 to 0.89 in the case of the slope-scale samples from these same sites, and was 0.85 in the case of the streamflow samples. While the overall performance of the sensor was thus rather satisfactory, the results pointed to the need for scale of site-specific calibrations to maximize the reliability of the predictions of sediment concentration by the POF (plastic optical fibre) sensor. This especially applied to the cases in which sediment concentrations were comparatively low, for example following mulching with forest residues.publishe
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