53 research outputs found

    Alkaloids in Erythrina

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    Erythrina species are used in popular medicine as sedative, anxiolytic, anti-inflammatory, and antihypertensive. In this work, we investigated the chemical composition of extracts obtained from leaves of E. falcata and E. crista-galli. The hypotensive potential of E. falcata and the mechanism of action were also studied. The extracts were obtained by maceration and infusion. The total content of phenolic compounds and flavonoids was estimated by spectrophotometric methods. The chemical constituents were studied performing a chromatographic analysis by UPLC-ESI-MS. For in vivo protocols, blood pressure and heart rate were measured by the invasive hemodynamic monitoring method. Different concentrations of extracts and drugs such as L-NAME, losartan, hexamethonium, and propranolol were administrated i.v. The results of total phenolic contents for E. falcata and E. crista-galli were 1.3193–1.4989 mgGAE/mL for maceration and 0.8771–0.9506 mgGAE/mL for infusion. In total flavonoids, the content was 7.7829–8.1976 mg RE/g for maceration and 9.3471–10.4765 RE mg/g for infusion. The chemical composition was based on alkaloids, suggesting the presence of erythristemine, 11β-methoxyglucoerysodine, erysothiopine, 11β-hydroxyerysodine-glucose, and 11-hydroxyerysotinone-rhamnoside. A potent dose-dependent hypotensive effect was observed for E. falcata, which may be related to the route of β-adrenergic receptors

    Radon and material radiopurity assessment for the NEXT double beta decay experiment

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    The Neutrino Experiment with a Xenon TPC (NEXT), intended to investigate the neutrinoless double beta decay using a high-pressure xenon gas TPC filled with Xe enriched in 136Xe at the Canfranc Underground Laboratory in Spain, requires ultra-low background conditions demanding an exhaustive control of material radiopurity and environmental radon levels. An extensive material screening process is underway for several years based mainly on gamma-ray spectroscopy using ultra-low background germanium detectors in Canfranc but also on mass spectrometry techniques like GDMS and ICPMS. Components from shielding, pressure vessel, electroluminescence and high voltage elements and energy and tracking readout planes have been analyzed, helping in the final design of the experiment and in the construction of the background model. The latest measurements carried out will be presented and the implication on NEXT of their results will be discussed. The commissioning of the NEW detector, as a first step towards NEXT, has started in Canfranc; in-situ measurements of airborne radon levels were taken there to optimize the system for radon mitigation and will be shown too.Comment: Proceedings of the Low Radioactivity Techniques 2015 workshop (LRT2015), Seattle, March 201

    NEXT-100 Technical Design Report (TDR). Executive Summary

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    In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (bbonu) in Xe-136 at the Laboratorio Subterraneo de Canfranc (LSC), in Spain. The document formalizes the design presented in our Conceptual Design Report (CDR): an electroluminescence time projection chamber, with separate readout planes for calorimetry and tracking, located, respectively, behind cathode and anode. The detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or 100 kg at 10 bar. This option builds in the capability to increase the total isotope mass by 50% while keeping the operating pressure at a manageable level. The readout plane performing the energy measurement is composed of Hamamatsu R11410-10 photomultipliers, specially designed for operation in low-background, xenon-based detectors. Each individual PMT will be isolated from the gas by an individual, pressure resistant enclosure and will be coupled to the sensitive volume through a sapphire window. The tracking plane consists in an array of Hamamatsu S10362-11-050P MPPCs used as tracking pixels. They will be arranged in square boards holding 64 sensors (8 times8) with a 1-cm pitch. The inner walls of the TPC, the sapphire windows and the boards holding the MPPCs will be coated with tetraphenyl butadiene (TPB), a wavelength shifter, to improve the light collection.Comment: 32 pages, 22 figures, 5 table

    Trophic niche partitioning of five skate species of genus Bathyraja in northern and central Patagonia, Argentina

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    Overexploitation of marine communities can lead to modifications in the structure of the food web and can force organisms like elasmobranchs to change their feeding habits. To evaluate the impact that fisheries have on food webs and on the interactions between species, it is necessary to describe and quantify the diet of the species involved and follow it through time. This study compares the diet of five skate species using the data obtained from the by-catch of the Argentine hake (Merluccius hubbsi) fishery in north and central Patagonia, Argentina. Diet composition was assessed by analysing the digestive tract contents and trophic overlapping between species of the genus Bathyraja: Bathyraja albomaculata, Bathyraja brachyurops, Bathyraja macloviana, Bathyraja magellanica and Bathyraja multispinis. A total of 184 stomachs were analysed. The diets of B. albomaculata and B. macloviana mainly comprised annelids, whereas that of B. brachyurops primarily comprised fish, including hake heads discarded by the fishery. The diets of B. magellanica and B. multispinis were largely based on crustaceans. Despite the morphological similarities and their shared preference for benthic habitats, no complete diet overlaps were found between the different species. These results suggest that these skate species have undergone a process of diet specialisation. This is a common feeding strategy that occurs to successfully eliminate competition when resources are limited, which corresponds to the conditions found in an environment being affected by the pressures of overfishing.Fil: Tschopp, Ayelen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Cristiani, Franco. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Garcia, Nestor Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Coscarella, Mariano Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; Argentin

    Evidence of association of the NLRP1 gene with giant cell arteritis

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    Recent studies have focused attention on the involvement of NLRP1 to confer susceptibility for extended autoimmune/inflammatory disorders, being considered a common risk factor in autoimmunity. NLRP1 provides a scaffold for the assembly of the inflammasome that activates caspases 1 and 5, required for processing and activation of the proinflammatory cytokines interleukin 1β (IL-1β), IL-18 and IL-33 and promoting inflammation

    Identification of the PTPN22 functional variant R620W as susceptibility genetic factor for giant cell arteritis

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    Objective: To analyse the role of the PTPN22 and CSK genes, previously associated with autoimmunity, in the predisposition and clinical phenotypes of giant cell arteritis (GCA). Methods: Our study population was composed of 911 patients diagnosed with biopsy-proven GCA and 8136 unaffected controls from a Spanish discovery cohort and three additional independent replication cohorts from Germany, Norway and the UK. Two functional PTPN22 polymorphisms (rs2476601/R620W and rs33996649/R263Q) and two variants of the CSK gene (rs1378942 and rs34933034) were genotyped using predesigned TaqMan assays. Results: The analysis of the discovery cohort provided evidence of association of PTPN22 rs2476601/R620W with GCA (PFDR=1.06E-04, OR=1.62, CI 95% 1.29 to 2.04). The association did not appear to follow a specific GCA subphenotype. No statistically significant differences between allele frequencies for the other PTPN22 and CSK genetic variants were evident either in the case/control or in stratified case analysis. To confirm the detected PTPN22 association, three replication cohorts were genotyped, and a consistent association between the PTPN22 rs2476601/R620W variant and GCA was evident in the overall meta-analysis (PMH=2.00E-06, OR=1.51, CI 95% 1.28 to 1.79). Conclusions: Our results suggest that the PTPN22 polymorphism rs2476601/R620W plays an important role in the genetic risk to GCA

    Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment

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    NEXT-DEMO is a large scale prototype and demonstrator of the NEXT-100 High Pressure Xenon Gas TPC, which will search for the neutrinoless double beta decay of Xe-136 using 100-150 kg of enriched xenon gas. The apparatus was built to prove the expected performance of NEXT-100, namely, energy resolution better than 1% FWHM at 2.5 MeV and event topological reconstruction. In this paper we describe the operation and initial results of the detector. A resolution of 1.7% FWHM at 511 keV (0.77% FWHM at 2.5 MeV) is obtained in the full fiducial volume of the detector. A topological analysis shows that electrons are identified by the characteristic blob energy deposit associated to the Bragg peak in 98.5% of the cases, with a rate of misidentification (two blobs) of 0.14%

    Present Status and Future Perspectives of the NEXT Experiment

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    NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector is a TPC, holding 100 kg of high-pressure xenon enriched in the 136Xe isotope. It is under construction in the Laboratorio Subterráneo de Canfranc in Spain, and it will begin operations in 2015. The NEXT detector concept provides an energy resolutionbetter than 1% FWHM and a topological signal that can be used to reduce the background. Furthermore, the NEXT technology can be extrapolated to a 1 ton-scale experiment
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