452 research outputs found

    Photocurrent study of all-printed photodetectors on paper made of different transition metal dichalcogenide nanosheets

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    We have inkjet-printed in-plane 'metal-semiconductor-metal' type photodetectors on paper, one of the cheapest flexible substrates, which is also recyclable and foldable, in contrast to traditional plastic substrates. The photodetectors are made by using graphene as electrodes and various transition metal dichalcogenides (TMDs) as photoactive component. In particular, we have tested MoS2, WS2, MoSe2 and MoTe2. Large differences in responsivity and sensitivity were observed for all of the TMDs measured, with MoS2 showing the highest sensitivity and MoTe2 producing the largest response. However, photodetectors made of MoTe2 show large decreases in responsivity after one week of exposure to air. The wavelength dependence of the responsivity in MoS2 based devices was further analyzed using a supercontinuum photocurrent spectroscopy setup, with the results suggesting a bolometric or photoelectric origin of the signal. We also report some simple approaches to enhance the device performance and tune the energy range at which the maximum in responsivity or sensitivity is observed

    Search for magnetic monopoles and stable particles with high electric charges in √s = 13 TeV pp collisions with the ATLAS detector

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    We present a search for magnetic monopoles and high-electric-charge objects using LHC Run 2 √s = 13 TeV proton-proton collisions recorded by the ATLAS detector. A total integrated luminosity of 138 fb−1 was collected by a specialized trigger. No highly ionizing particle candidate was observed. Considering the Drell-Yan and photon-fusion pair production mechanisms as benchmark models, cross-section upper limits are presented for spin-0 and spin-1/2 magnetic monopoles of magnetic charge 1gD and 2gD and for high-electric-charge objects of electric charge 20 ≤ |z| ≤ 100, for masses between 200 GeV and 4000 GeV. The search improves by approximately a factor of three the previous cross-section limits on the Drell-Yan production of magnetic monopoles and high-electric charge objects. Also, the first ATLAS limits on the photon-fusion pair production mechanism of magnetic monopoles and high-electric-charge objects are obtained

    Search for vector-boson resonances decaying into a top quark and a bottom quark using pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for a new massive charged gauge boson, W′, is performed with the ATLAS detector at the LHC. The dataset used in this analysis was collected from proton-proton collisions at a centre-of-mass energy of √s = 13 TeV, and corresponds to an integrated luminosity of 139 fb−1. The reconstructed tb invariant mass is used to search for a W′ boson decaying into a top quark and a bottom quark. The result is interpreted in terms of a W′ boson with purely right-handed or left-handed chirality in a mass range of 0.5–6 TeV. Different values for the coupling of the W′ boson to the top and bottom quarks are considered, taking into account interference with single-top-quark production in the s-channel. No significant deviation from the background prediction is observed. The results are expressed as upper limits on the W′ → tb production cross-section times branching ratio as a function of the W′-boson mass and in the plane of the coupling vs the W′-boson mass

    Silica “SHB”chiral Pc-L* Cu(I) complexes for continuous flow cyclopropanation reactions with carbon dioxide as a carrier

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    We have recently reported that copper(I) complexes of the new C1-symmetric pyridine-based 12-membered tetraaza macrocycles, Pyridine Containing Ligands (Pc-L*), are competent catalysts in the asymmetric cyclopropanation. In order to improve our catalytic system Cu(I) complexes based on Pc-L* ligands were heterogeneised on mesoporous ordered and non-ordered silicas (Davisil B, MCM-41, etc.) by the Supported by HydrogenBond (SHB) method. Supported catalysts C were tested in enantioselective cyclopropanation in batch conditions showing good catalytic activities employing ethyl diazoacetate (EDA) as carbene precursor in n-hexane. The silica support has a strong influence on the diastereoselective outcome of the reaction, favoring the formation of the more challenging cis-isomer. Then, C were tested as catalyst for the cyclopropanation reaction under flow conditions focusing our attention on the use of supercritical CO2. Under optimised conditions, the catalyst was stable over at least 10 h of continuous flow, without drop in activity or selectivity

    Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight

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    Indexación: Web of Science; PubMedBackground Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages. Results A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. Conclusions We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.http://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-016-0789-

    Grapevine field experiments reveal the contribution of genotype, the influence of environment and the effect of their interaction (GXE) on the berry transcriptome

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    Changes in the performance of genotypes in different environments are defined as genotype x environment (G x E) interactions. In grapevine (Vitis vinifera), complex interactions between different genotypes and cli- mate, soil and farming practices yield unique berry qualities. However, the molecular basis of this phe- nomenon remains unclear. To dissect the basis of grapevine G x E interactions we characterized berry transcriptome plasticity, the genome methylation landscape and within-genotype allelic diversity in two genotypes cultivated in three different environments over two vintages. We identified, through a novel data-mining pipeline, genes with expression profiles that were: unaffected by genotype or environment, genotype-dependent but unaffected by the environment, environmentally-dependent regardless of geno- type, and GxE-related. The GxE-related genes showed different degrees of within-cultivar allelic diversity in the two genotypes and were enriched for stress responses, signal transduction and secondary metabo- lism categories. Our study unraveled the mutual relationships between genotypic and environmental vari- ables during GxE interaction in a woody perennial species, providing a reference model to explore how cultivated fruit crops respond to diverse environments. Also, the pivotal role of vineyard location in deter- mining the performance of different varieties, by enhancing berry quality traits, was unraveled

    Addition of capsaicin in the mdiet of turkeys: effects on growth performance and antioxidant and oxidant status in serum and in meat.

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    Abstract: The objective of this study was to evaluate whether the addition of different levels of capsaicin in the diet of female turkeys has beneficial effects on growth performance and the antioxidant and oxidant status in serum and meat. A total of 150 female turkeys were distributed in a completely randomized design with three treatments with five replicates per treatment and ten birds per experimental unit. Treatments were identified as control (without additive); T400 – basal diet containing 400 mg/kg of pepper extract per kg of feed; and T800 – basal diet supplemented with 800 mg/kg of pepper extract per kg of feed. Growth performance was measured on days 1 and 20 of the experiment. Blood samples were collected at 20 days of the experiment for analysis of the oxidant and antioxidant status, and at 20 days, five birds were euthanized per treatment for the analysis of the oxidant and antioxidant status of the meat. The turkeys fed diet supplemented with capsaicin had lower feed intake and better feed:gain ratio. Turkeys in the T800 treatment showed a reduction in serum levels of reactive oxygen species (ROS) and thiobarbituric acid, and this same effect was observed for ROS in their breast meat. Capsaicin supplementation improves feed conversion and reduces feed intake without altering weight gain in female turkeys. Furthermore, the addition of 800 g/ton reduces lipid peroxidation and protein oxidation in the serum and reduces protein oxidation in broiler turkey meat. Resumo:O objetivo deste estudo foi avaliar se a adição de diferentes níveis de capsaicina na dieta de perus fêmeas têm efeitos benéficos no desempenho e no status antioxidante e oxidante no soro e na carne. Foram utilizadas 150 perus fêmeas distribuídas em delineamento inteiramente casualizado com três tratamentos com cinco repetições por tratamento e dez aves por unidade experimental. Os tratamentos foram identificados como controle (sem aditivo); T400 – dieta basal contendo 400 mg/kg de extrato de pimenta por kg de ração; e T800 – dieta basal suplementada com 800 mg/kg de extrato de pimenta por kg de ração. O desempenho foi medido nos dias 1 e 20 do experimento. Amostras de sangue foram coletadas aos 20 dias de experimento para análise do estado oxidante e antioxidante, e aos 20 dias cinco aves foram eutanasiadas por tratamento para análise do estado oxidante e antioxidante da carne. Os perus alimentados com dieta suplementada com capsaicina apresentaram menor consumo de ração e melhor conversão alimentar. Os perus no tratamento T800 apresentaram redução nos níveis séricos de espécies reativas de oxigênio (ROS) e ácido tiobarbitúrico, e esse mesmo efeito foi observado para ROS na carne do peito. A suplementação de capsaicina melhora a conversão alimentar e reduz o consumo de ração sem alterar o ganho de peso em perus fêmeas. Além disso, a adição de 800 g/ton reduz a peroxidação lipídica e a oxidação de proteínas no soro e reduz a oxidação de proteínas na carne de peru de corte
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