105 research outputs found

    Using plant-based preparations to protect common bean against halo blight disease: the potential of nettle to trigger the immune system

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    Halo blight disease of beans (Phaseolus vulgaris L.), caused by the bacterium Pseudomonas syringae pv. phaseolicola (Pph), is responsible for severe losses in crop production worldwide. As the current agronomic techniques used are not effective, it is necessary to search for new ones which may prevent disease in common bean. In this study, we challenged four plant-based preparations (PBPs), with no other agronomic uses, as they come from industrial waste (grapevine pomace (R-G) and hop residue (R-H)) or wild plants (Urtica dioica (U) and Equisetum sp. (E)), to be used as immune defense elicitors against Pph in common bean. After studying their inhibitory effect against Pph growth by bioassays, the two most effective PBPs (R-G and U) were applied in common bean plants. By measuring the total H2O2, lipid peroxidation, and antioxidant enzymatic activities, as well as the expression of six defense-related genes-PR1, WRKY33, MAPKK, RIN4, and PAL1-, it was observed that U-PBP application involved a signaling redox process and the overexpression of all genes, mostly PR1. First infection trials in vitro suggested that the application of U-PBP involved protection against Pph. The elicitation of bean defense with U-PBP involved a decrease in some yield parameters, but without affecting the final production. All these findings suggest a future use of U-PBP to diminish halo blight disease

    Cu-Catalyzed Silylation of Alkynes: A Traceless 2-Pyridylsulfonyl Controller Allows Access to either Regioisomer on Demand

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/jacs.5b02667The Cu-catalyzed silylation of terminal and internal alkynes bearing a 2-pyridyl sulfonyl group (SO2Py) at the propar-gylic position affords a breadth of vinyl silanes in good yields and excellent regio- and stereocontrol under mild conditions. The directing SO2Py group is essential in terms of reaction efficiency and chemoselectivity. Importantly, this group also provides the ability to reverse the regiochemical outcome of the reaction, opening the access to either regioisomer without modification of the starting substrate by virtue of an in situ base-promoted alkyne to allene equilibration which takes place prior to the silylcupration process. Furthermore, removal of the directing SO2Py allows for further elaboration of the silylation products. In particular, a one-pot tandem alkyne silylation/allylic substitution sequence, in which both steps are catalyzed by the same Cu species, opens up a new approach for the access to either formal hydrosilylation regioisomer of unsymmetrical aliphatic-substituted internal alkynes from propargyl sulfonesThis work was supported by the Ministerio de Economía y Com-petitividad (MINECO, CTQ2012-35790) and the European Union for a Marie Curie Career Integration Grant (to P.M). J. R. and P.M. thank MINECO for a FPI predoctoral fellowship and a Ramón y Cajal contract, respectivel

    System size resonance in an attractor neural network

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    We study the response of an attractor neural network, in the ferromagnetic phase, to an external, time-dependent stimulus, which drives the system periodically two different attractors. We demonstrate a non-trivial dependance of the system via a system size resonance, by showing a signal amplification maximum at a certain finite size.Comment: 7 pages, 9 figures, submitted to Europhys. Let

    Deciphering the enzymatic target of a new family of antischistosomal agents bearing a quinazoline scaffold using complementary computational tools.

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    A previous phenotypic screening campaign led to the identification of a quinazoline derivative with promising in vitro activity against Schistosoma mansoni. Follow-up studies of the antischistosomal potential of this candidate are presented here. The in vivo studies in a S. mansoni mouse model show a significant reduction of total worms and a complete disappearance of immature eggs when administered concomitantly with praziquantel in comparison with the administration of praziquantel alone. This fact is of utmost importance because eggs are responsible for the pathology and transmission of the disease. Subsequently, the chemical optimisation of the structure in order to improve the metabolic stability of the parent compound was carried out leading to derivatives with improved drug-like properties. Additionally, the putative target of this new class of antischistosomal compounds was envisaged by using computational tools and the binding mode to the target enzyme, aldose reductase, was proposed

    Dielectric behaviour of Hf-doped CaCu₃Ti₄O₁₂ ceramics obtained by conventional synthesis and reactive sintering

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    CaCu₃ (Ti₄₋ₓ Hfₓ )O₁₂ ceramics ( x  = 0.04, 0.1 and 0.2) were prepared by conventional synthesis (CS) and through reactive sintering (RS), in which synthesis and sintering of the material take place in one single step. The microstructure and the dielectric properties of Hf-doped CCTO (CCTOHf) have been studied by XRD, FE-SEM, AFM, Raman and impedance spectroscopy (IS) in order to correlate the structure, microstructure and the electrical properties. Samples prepared by reactive sintering show slightly higher dielectric constant than those prepared by conventional synthesis in the same way than the pure CCTO. Dielectric constant and dielectric losses decrease slightly increasing Hf content. For CCTOHf ceramics with x  > 0.04 for CS and x  > 0.1 for RS, a secondary phase HfTiO₄ appears. As expected, the reactive sintering processing method allows a higher incorporation of Hf in the CCTO lattice than the conventional synthesis one.Facultad de Ciencias Exacta

    Prediction of peripheral neuropathy in multiple myeloma patients receiving bortezomib and thalidomide: a genetic study based on a single nucleotide polymorphism array

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    GEM (Grupo Español de MM)/PETHEMA (Programa para el Estudio de la Terapéutica en Hemopatías Malignas) cooperative study group.Bortezomib- and thalidomide-based therapies have significantly contributed to improved survival of multiple myeloma (MM) patients. However, treatment-induced peripheral neuropathy (TiPN) is a common adverse event associated with them. Risk factors for TiPN in MM patients include advanced age, prior neuropathy, and other drugs, but there are conflicting results about the role of genetics in predicting the risk of TiPN. Thus, we carried out a genome-wide association study based on more than 300 000 exome single nucleotide polymorphisms in 172 MM patients receiving therapy involving bortezomib and thalidomide. We compared patients developing and not developing TiPN under similar treatment conditions (GEM05MAS65, NCT00443235). The highest-ranking single nucleotide polymorphism was rs45443101, located in the PLCG2 gene, but no significant differences were found after multiple comparison correction (adjusted P =.1708). Prediction analyses, cytoband enrichment, and pathway analyses were also performed, but none yielded any significant findings. A copy number approach was also explored, but this gave no significant results either. In summary, our study did not find a consistent genetic component associated with TiPN under bortezomib and thalidomide therapies that could be used for prediction, which makes clinical judgment essential in the practical management of MM treatment.This work has been partially supported by grants of the Instituto de Salud Carlos III (ISCIII) (CP13/00080), ISCIII (PI12/02311), Red Temática de Investigación Cooperativa en Cáncer (RD12/0036/0069) (RD12/0036/0061), Ministerio de Economía y Competitividad/ Fondo Europeo de Desarrollo Regional (FEDER) “Una manera de hacer Europa” (Innocampus; CEI‐2010‐1‐0010), Asociación Española Contra el Cancer (GCB120981SAN), and Joan Rodes (JR 14/00016). M.E.S. is supported by the Miguel Servet program (CP13/00080) of the ISCIII (Ministerio de Economía y Competitividad).Peer Reviewe

    Quinine doped hybrid sol-gel coatings for wave guiding and optical applications

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    Pure and quinine doped silica coatings have been prepared over sodalime glasses. The coatings were consolidated at low temperature (range 60-180 A degrees C) preserving optical activity of quinine molecule. We designed a device to test the guiding properties of the coatings. We confirmed with this device that light injected in pure silica coatings is guided over distances of meters while quinine presence induces isotropic photoluminescence. With the combined use of both type of coatings, it is possible to design light guiding devices and illuminate regions in glass elements without electronic circuits

    Resolución estructural en 3D de electrocerámicas mediante microscopía Raman confocal

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    Las propiedades de los materiales cerámicos son una combinación entre las propiedades intrínsecas, definidas por los granos cristalinos, y las propiedades extrínsecas, como son bordes de grano y fases secundarias. La relación entre estos dos elementos produce en muchas ocasiones, la presencia de propiedades inusuales que son la base de muchos materiales electrocerámicos. Sirvan como ejemplo algunos materiales tipo como son: varistores cerámicos, termistores, materiales con coeficiente de resistividad positivo, sensores de borde de grano, etc. En un material electrocerámico con respuesta funcional la correlación entre estructura-microestructura -propiedades es una constante, tanto en la etapa de diseño en laboratorio como en la etapa de producción industrial. El empleo de Microscopía Raman Confocal (MRC) se propone como una metodología relevante para el estudio de los factores que afectan a dichas correlaciones en materiales electrocerámicos. La técnica de MRC constituye una potente herramienta que permite determinar no solo la estructura sino las interacciones entre los elementos microestructurales. La correlación entre estas variables con las propiedades funcionales y la posibilidad de determinar las mismas en condiciones de operación, abren unas posibilidades que hasta la fecha solo estaban en la imaginación de los científicos. En esta presentación se resumen brevemente algunos de los principios relacionados con la técnica de Microscopía Raman Confocal, que junto con ejemplos seleccionados permiten visualizar aspectos relacionados con: la orientación de cristales, identificación fases cristalinas; resolución de nanoestructuras e interfases; determinación y dinámica de dominios ferroeléctricos; presencia de tensiones mecánicas; fenómenos de conducción,... sobre diferentes materiales cerámicos. Los trabajos mostrados son ejemplos de alta resolución en 3D de materiales funcionales como son los materiales electrocerámicos

    Screening of a PDE-focused library identifies imidazoles with in vitro and in vivo antischistosomal activity

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    We report the evaluation of 265 compounds from a PDE-focused library for their antischistosomal activity, assessed in vitro using Schistosoma mansoni. Of the tested compounds, 171 (64%) displayed selective in vitro activity, with 16 causing worm hypermotility/spastic contractions and 41 inducing various degrees of worm killing at 100 μM, with the surviving worms displaying sluggish movement, worm unpairing and complete absence of eggs. The compounds that did not affect worm viability (n = 72) induced a complete cessation of ovipositing. 82% of the compounds had an impact on male worms whereas female worms were barely affected. In vivo evaluation in S. mansoni-infected mice with the in vitro ‘hit’ NPD-0274 at 20 mg/kg/day orally for 5 days resulted in worm burden reductions of 29% and intestinal tissue egg load reduction of 35% at 10 days post-treatment. Combination of praziquantel (PZQ) at 10 mg/kg/day for 5 days with NPD-0274 or NPD-0298 resulted in significantly higher worm killing than PZQ alone, as well as a reduction in intestinal tissue egg load, disappearance of immature eggs and an increase in the number of dead eggs
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