103 research outputs found

    Highly Sensitive Fluorescence Probe Based on Functional SBA-15 for Selective Detection of Hg2+

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    An inorganic–organic hybrid fluorescence chemosensor (DA/SBA-15) was prepared by covalent immobilization of a dansylamide derivative into the channels of mesoporous silica material SBA-15 via (3-aminopropyl)triethoxysilane (APTES) groups. The primary hexagonally ordered mesoporous structure of SBA-15 was preserved after the grafting procedure. Fluorescence characterization shows that the obtained inorganic–organic hybrid composite is highly selective and sensitive to Hg2+ detection, suggesting the possibility for real-time qualitative or quantitative detection of Hg2+ and the convenience for potential application in toxicology and environmental science

    Surface Enhanced Raman Scattering and Gated Materials for Sensing Applications: The Ultrasensitive Detection of Mycoplasma and Cocaine

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    [EN] We present herein a novel combination of gated mesoporous silica nanoparticles (MSNs) and surface-enhanced Raman scattering (SERS) for sensing applications. As a proof-of-concept, we show the design of a system comprising MSNs loaded with crystal violet (CV), a molecule with high Raman cross section acting as SERS reporter, and capped with either a suitable DNA sequence for the detection of Mycoplasma genomic DNA or with an aptamer that selectively coordinates cocaine. In both cases the presence of the corresponding target analyte in solution (i.e., genomic DNA or cocaine) resulted in the release of CV. CV delivery was detected by SERS upon adsorption on gold nanotriangles (AuNTs), which display an efficient electromagnetic field enhancement and a high colloidal stability. By using this novel procedure a limit of detection of at least 30 copies DNA per mL was determined for the detection of Mycoplasma genomic DNA, whereas cocaine was detected at concentrations as low as 10 nm.M.C.-P. acknowledges an FPU Scholarship from the Spanish Ministry of Education, Culture and Sports. L.M.L.- M. acknowledges financial support from the European Research Council (ERC Advanced Grant #267867 Plasmaquo) and the European Union's Seventh Framework Programme (FP7/2007-2013 under Grant Agreement No 312184, SACS). M.O. is grateful to the Universitat Politecnica de Valencia for a FPI-UPV grant. Financial support from the Spanish Government (Project MAT2015-64139-C4-1-R MINECO/FEDER) and the Generalitat Valenciana (Project PROMETEOII/2014/047) is gratefully acknowledged.Oroval, M.; Coronado Puchau, M.; Langer, J.; Sanz-Ortiz, MN.; Ribes, À.; Aznar, E.; Coll Merino, MC.... (2016). Surface Enhanced Raman Scattering and Gated Materials for Sensing Applications: The Ultrasensitive Detection of Mycoplasma and Cocaine. Chemistry - A European Journal. 22(38):13488-13495. https://doi.org/10.1002/chem.201602457S1348813495223

    Multi-Centre, Multi-Vendor and Multi-Disease Cardiac Segmentation: The M&Ms Challenge

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    The emergence of deep learning has considerably advanced the state-of-the-art in cardiac magnetic resonance (CMR) segmentation. Many techniques have been proposed over the last few years, bringing the accuracy of automated segmentation close to human performance. However, these models have been all too often trained and validated using cardiac imaging samples from single clinical centres or homogeneous imaging protocols. This has prevented the development and validation of models that are generalizable across different clinical centres, imaging conditions or scanner vendors. To promote further research and scientific benchmarking in the field of generalizable deep learning for cardiac segmentation, this paper presents the results of the Multi-Centre, Multi-Vendor and Multi-Disease Cardiac Segmentation (M&Ms) Challenge, which was recently organized as part of the MICCAI 2020 Conference. A total of 14 teams submitted different solutions to the problem, combining various baseline models, data augmentation strategies, and domain adaptation techniques. The obtained results indicate the importance of intensity-driven data augmentation, as well as the need for further research to improve generalizability towards unseen scanner vendors or new imaging protocols. Furthermore, we present a new resource of 375 heterogeneous CMR datasets acquired by using four different scanner vendors in six hospitals and three different countries (Spain, Canada and Germany), which we provide as open-access for the community to enable future research in the field

    The Drosophila FoxA Ortholog Fork Head Regulates Growth and Gene Expression Downstream of Target of Rapamycin

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    Forkhead transcription factors of the FoxO subfamily regulate gene expression programs downstream of the insulin signaling network. It is less clear which proteins mediate transcriptional control exerted by Target of rapamycin (TOR) signaling, but recent studies in nematodes suggest a role for FoxA transcription factors downstream of TOR. In this study we present evidence that outlines a similar connection in Drosophila, in which the FoxA protein Fork head (FKH) regulates cellular and organismal size downstream of TOR. We find that ectopic expression and targeted knockdown of FKH in larval tissues elicits different size phenotypes depending on nutrient state and TOR signaling levels. FKH overexpression has a negative effect on growth under fed conditions, and this phenotype is not further exacerbated by inhibition of TOR via rapamycin feeding. Under conditions of starvation or low TOR signaling levels, knockdown of FKH attenuates the size reduction associated with these conditions. Subcellular localization of endogenous FKH protein is shifted from predominantly cytoplasmic on a high-protein diet to a pronounced nuclear accumulation in animals with reduced levels of TOR or fed with rapamycin. Two putative FKH target genes, CG6770 and cabut, are transcriptionally induced by rapamycin or FKH expression, and silenced by FKH knockdown. Induction of both target genes in heterozygous TOR mutant animals is suppressed by mutations in fkh. Furthermore, TOR signaling levels and FKH impact on transcription of the dFOXO target gene d4E-BP, implying a point of crosstalk with the insulin pathway. In summary, our observations show that an alteration of FKH levels has an effect on cellular and organismal size, and that FKH function is required for the growth inhibition and target gene induction caused by low TOR signaling levels

    Contrast Adaptation Contributes to Contrast-Invariance of Orientation Tuning of Primate V1 Cells

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    BACKGROUND: Studies in rodents and carnivores have shown that orientation tuning width of single neurons does not change when stimulus contrast is modified. However, in these studies, stimuli were presented for a relatively long duration (e. g., 4 seconds), making it possible that contrast adaptation contributed to contrast-invariance of orientation tuning. Our first purpose was to determine, in marmoset area V1, whether orientation tuning is still contrast-invariant with the stimulation duration is comparable to that of a visual fixation. METHODOLOGY/PRINCIPAL FINDINGS: We performed extracellular recordings and examined orientation tuning of single-units using static sine-wave gratings that were flashed for 200 msec. Sixteen orientations and three contrast levels, representing low, medium and high values in the range of effective contrasts for each neuron, were randomly intermixed. Contrast adaptation being a slow phenomenon, cells did not have enough time to adapt to each contrast individually. With this stimulation protocol, we found that the tuning width obtained at intermediate contrast was reduced to 89% (median), and that at low contrast to 76%, of that obtained at high contrast. Therefore, when probed with briefly flashed stimuli, orientation tuning is not contrast-invariant in marmoset V1. Our second purpose was to determine whether contrast adaptation contributes to contrast-invariance of orientation tuning. Stationary gratings were presented, as previously, for 200 msec with randomly varying orientations, but the contrast was kept constant within stimulation blocks lasting >20 sec, allowing for adaptation to the single contrast in use. In these conditions, tuning widths obtained at low contrast were still significantly less than at high contrast (median 85%). However, tuning widths obtained with medium and high contrast stimuli no longer differed significantly. CONCLUSIONS/SIGNIFICANCE: Orientation tuning does not appear to be contrast-invariant when briefly flashed stimuli vary in both contrast and orientation, but contrast adaptation partially restores contrast-invariance of orientation tuning

    Design of fluorescent materials for chemical sensing

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    Report from the first European Dermato-Epidemiology Network forum.

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    The first European Dermato-Epidemiology Network (EDEN) forum was held on 30-31 March 2017 in Madrid, Spain. Dermatoepidemiology describes the study of causes, prevention, health services research and evaluation of interventions of skin diseases. EDEN aims to promote high-quality research, share expertise and facilitate collaboration. These aims were achieved during the EDEN forum by including a preconference course on skin cancer epidemiology; having excellent world-leading guest speakers on causality, quality of care, pharmacoepidemiology and missing data analysis; and including delegates who presented and discussed innovative research findings. The meeting brought together delegates from 11 different countries. We welcome everyone with an interest in clinical research and epidemiology related to skin disease to attend next year's meeting in March 2018 in Berlin
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