1,258 research outputs found

    Production of micropropagated melon plantlets adapted to saline environment

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    An experiment was carried out to evaluate the behaviour on salt stress induced by sodium chloride of two melon clones obtained from micropropagation. Since arbuscular mycorrhizal (AM) fungi seem to increase salt tolerance in some crops, at acclimatisation melon plantlets were mycorrhizal with an AM fungus. The root systems of both mycorrhizal and non mycorrhizal plants were exposed to increasing salt concentrations and then placed in distilled water to study the wilting response and the recovery of plants. Observations were made on several morphological parameters, in particular to verify the modification of root system morphology caused by AM fungus, as demonstrated already by several studies. The analysis of infected roots was carried out following Phillips and Hayman's protocol (1970). Afterwards, the specimen was read using an optical microscope

    Experimental Implementation of a Concatenated Quantum Error-Correcting Code

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    Concatenated coding provides a general strategy to achieve the desired level of noise protection in quantum information storage and transmission. We report the implementation of a concatenated quantum error-correcting code able to correct against phase errors with a strong correlated component. The experiment was performed using liquid-state nuclear magnetic resonance techniques on a four spin subsystem of labeled crotonic acid. Our results show that concatenation between active and passive quantum error-correcting codes offers a practical tool to handle realistic noise contributed by both independent and correlated errors.Comment: 4 pages, 2 encapsulated eps figures. REVTeX4 styl

    The LH/hCG Axis in Endometrial Cancer: A New Target in the Treatment of Recurrent or Metastatic Disease

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    Endometrial cancer (EC) is a hormone-dependent cancer that currently represents the most frequent malignancy of the female reproductive tract. The involvement of steroid hormones in EC etiology and progression has been reported. More recently, gonadotropins, and, in particular LH/hCG, are emerging as novel regulators of tumor progression. In the present review, we discuss the role of the LH/hCG axis (i.e. LH/hCG and its receptors, LH/hCG-R) in both gonadal and nongonadal tissues, in physiological and neoplastic conditions. In cancer cells, LH/hCG mainly controls cell proliferation and apoptosis. In particular, in EC LH/hCG improves cell invasiveness, through a mechanism which involves the LH/hCG-R, which in turn activate protein kinase A and modulate integrin adhesion receptors. Indeed, the LH/hCG-R mRNA is expressed in primary ECs and this expression correlates with LH/hCG-induced cell invasiveness in vitro. These results lead to hypothesize that recurrent and metastatic ECs, which express LH/hCG-R, could benefit from therapies aimed at decreasing LH levels, through Gn-RH analogues. Hence, the LH/hCG axis could represent a prognostic factor and a new therapeutic target in EC

    Flexible ecoflex®/graphene nanoplatelet foams for highly sensitive low-pressure sensors

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    The high demand for multifunctional devices for smart clothing applications, human motion detection, soft robotics, and artificial electronic skins has encouraged researchers to develop new high-performance flexible sensors. In this work, we fabricated and tested new 3D squeezable Ecoflex® open cell foams loaded with different concentrations of graphene nanoplatelets (GNPs) in order to obtain lightweight, soft, and cost-effective piezoresistive sensors with high sensitivity in a low-pressure regime. We analyzed the morphology of the produced materials and characterized both the mechanical and piezoresistive response of samples through quasi-static cyclic compression tests. Results indicated that sensors infiltrated with 1 mg of ethanol/GNP solution with a GNP concentration of 3 mg/mL were more sensitive and stable compared to those infiltrated with the same amount of ethanol/GNP solution but with a lower GNP concentration. The electromechanical response of the sensors showed a negative piezoresistive behavior up to ~10 kPa and an opposite trend for the 10–40 kPa range. The sensors were particularly sensitive at very low deformations, thus obtaining a maximum sensitivity of 0.28 kPa−1 for pressures lower than 10 kPa

    Opinion dynamics: rise and fall of political parties

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    We analyze the evolution of political organizations using a model in which agents change their opinions via two competing mechanisms. Two agents may interact and reach consensus, and additionally, individual agents may spontaneously change their opinions by a random, diffusive process. We find three distinct possibilities. For strong diffusion, the distribution of opinions is uniform and no political organizations (parties) are formed. For weak diffusion, parties do form and furthermore, the political landscape continually evolves as small parties merge into larger ones. Without diffusion, a pattern develops: parties have the same size and they possess equal niches. These phenomena are analyzed using pattern formation and scaling techniques.Comment: 5 pages, 5 figure

    Microfabricated and multilayered PLGA structure for the development of co-cultured in vitro liver models

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    One of the main advantages of having an in vitro model is the possibility of reducing toxic effects of drugs on human body and evaluate their response to pharmacological treatments to improve the efficacy of a patient-specific therapy. The limitation of such in vitro model is the use of monolayer hepatocytes cultures that show some problems of protein secretion and hepatic functionality. In order to overcome these drawbacks, we present two innovative multilayer structures based on micro-stamped poly(lactic-co-glycolic acid) (PLGA) structures and hepatocytes and fibroblast co-cultures. In particular, the first model consisted of 1 up to 5 layers of PLGA seeded with the previously cited co-culture, while the second model consisted of various sandwich structures of PLGA functionalised (or not) with collagen and seeded with hepatocytes and/or fibroblasts. A mechanical analysis, contact angle and surface charge density measurements were carried out. After these preliminary tests, a metabolic analysis was performed evaluating glucose consumption and urea and albumin production over a culture period of 11 days. Results showed promising application of these in vitro liver models, in particular considering the field of cirrhotic liver treatment

    Spatially distinct, temporally stable microbial populations mediate biogeochemical cycling at and below the seafloor in hydrothermal vent fluids

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    © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Microbiology 20 (2018): 769–784, doi:10.1111/1462-2920.14011.At deep-sea hydrothermal vents, microbial communities thrive across geochemical gradients above, at, and below the seafloor. In this study, we determined the gene content and transcription patterns of microbial communities and specific populations to understand the taxonomy and metabolism both spatially and temporally across geochemically different diffuse fluid hydrothermal vents. Vent fluids were examined via metagenomic, metatranscriptomic, genomic binning, and geochemical analyses from Axial Seamount, an active submarine volcano on the Juan de Fuca Ridge in the NE Pacific Ocean, from 2013 to 2015 at three different vents: Anemone, Marker 33, and Marker 113. Results showed that individual vent sites maintained microbial communities and specific populations over time, but with spatially distinct taxonomic, metabolic potential, and gene transcription profiles. The geochemistry and physical structure of each vent both played important roles in shaping the dominant organisms and metabolisms present at each site. Genomic binning identified key populations of SUP05, Aquificales and methanogenic archaea carrying out important transformations of carbon, sulfur, hydrogen, and nitrogen, with groups that appear unique to individual sites. This work highlights the connection between microbial metabolic processes, fluid chemistry, and microbial population dynamics at and below the seafloor and increases understanding of the role of hydrothermal vent microbial communities in deep ocean biogeochemical cycles.Gordon and Betty Moore Foundation Grant Number: GBMF3297; NSF Center for Dark Energy Biosphere Investigations Grant Number: OCE—0939564; Schmidt Ocean Institut

    Cardiopatias Congénitas Complexas: Influência do Diagnóstico Pré-Natal

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    INTRODUCTION: Complex congenital heart disease is a group of severe conditions. Prenatal diagnosis has implications on morbidity and mortality for most severe conditions. The purpose of this work was to evaluate the influence of prenatal diagnosis and distance of residence and birth place to a reference center, on immediate morbidity and early mortality of complex congenital heart disease. MATERIAL AND METHODS: Retrospective study of complex congenital heart disease patients of our Hospital, born between 2007 and 2012. RESULTS: There were 126 patients born with complex congenital heart disease. In 95%, pregnancy was followed since the first trimester, with prenatal diagnosis in 42%. There was a statistically significant relation between birth place and prenatal diagnosis. Transposition of great arteries was the most frequent complex congenital heart disease (45.2%), followed by pulmonary atresia with ventricular septal defect (17.5%) and hypoplastic left ventricle (9.5%). Eighty-two patients (65.1%) had prostaglandin infusion and 38 (30.2%)were ventilated before an intervention. Surgery took place in the neonatal period in 73%. Actuarial survival rate at 30 days, 12 and 24 months was 85%, 80% and 75%, respectively. There was no statistically significant relation between prenatal diagnosis and mortality. DISCUSSION: Most patients with complex congenital heart disease did not have prenatal diagnosis. All cases with prenatal diagnosis were born in a tertiary center. Prenatal diagnosis did not influence significantly neonatal mortality, as already described in other studies with heterogeneous complex heart disease. CONCLUSION: prenatal diagnosis of complex congenital heart disease allowed an adequate referral. Most patients with complex congenital heart disease were not diagnosed prenatally. This data should be considered when planning prenatal diagnosis of congenital heart disease

    Solid-state electrochromic devices based on poly(trimethylene carbonate) and lithium salts

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    The application of solid polymer electrolytes as dual-function electrolyte/adhesive components in electrochromic devices and the preliminary characterization of the resulting prototype displays is described in this paper. An asymmetric device configuration, represented schematically as glass/ZnO:Ga2O3/WO3/polymer electrolyte/ZnO:Ga2O3/glass, was chosen. Electrolytes with compositions of n between 3 and 10, where n represents the molar ratio of poly(trimethylene carbonate), p(TMC), ((CO)OCH2CH2CH2O), units per guest lithium ion, were prepared by solvent casting. The electrochromic switching performance was characterized as a function of salt type and salt concentration. The average transmittance in the visible region of the spectrum was above 63% for all the bleached samples characterized. After coloration the structures assembled with both p(TMC)nLiClO4 and p(TMC)nLiBF4 presented an average transmittance in the visible wavelength region above 39%.Fundação para a Ciência e Tecnologia (FCT
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