1,277 research outputs found

    Quantifying phase transformation during the manufacturing process of AISI 430 ferritic stainless steel

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    The effect of ferrite to austenite transformation phenomenon on microstructure and annealing performance of AISI 430 (EN 1.4016) ferritic stainless steel 16%Cr-0.04%C and 17%Cr-0.02%C was studied by electron backscatter diffraction and X-ray diffraction. Hot-rolled and annealed specimens of each ferritic stainless steel were collected from manufacturing route, where different states were analysed. Chemical composition shift of AISI 430 is correlated to microstructural behaviour of each material, while annealing temperature impact over grain growth phenomena is discussed

    Dendrimers-modified solid supports: towards nanostructures materials for clinical diagnostic

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    Conferencia Invitada al XXXIV Reunion Bienal de la Real Sociedad Española de Quimica. Santander, 2013The design and synthesis of new materials for biomedical applications is a high-priority research topic in a number of biomedical areas. The rapid development of nanotechnology over the past few decades has created wide prospects for using nano- and micro-scale materials in such areas, where careful control of interactions between particles and biosystems is essential for effective use of these materials in biomedicine. Worth special note in this respect is the use of nanoparticles in diagnostic assays, where chemists are playing an increasingly role in designing and producing new materials for manufacturing sensors affording increased sensitivity and selectivity relative to conventional diagnostic systems. The three-dimensional architecture of dendrimeric systems confers them some intrinsic features such as structural homogeneity, integrity, controlled composition and high-density multidentate homogeneous ends ready for (bio)conjugation. These properties make dendrimeric systems unique and stable enough for a variety of applications. This has boosted the use of dendrimers for biosensing purposes in recent years. We describe here recent progress in the preparation of new materials for biosensor applications. Specifically, we report on the use of zeolites and silica particles as a solid support for RadioAllergoSorbent Test (RAST) with a view to its use as a complementary diagnostic method for identifying allergic responses to drugs. To this end, we prepared nanoconjugated Dendrimeric Antigens (DeAn) peripherally decorated with the suspected amoxicillin hapten. Zeolites and Silica particles were modified with these novel synthetic Dendrimeric Antigens to obtain DeAn@Zeolite or SiO2NP which constitutes an effective, innovative nano system for biosensing

    Oxygen reduction using a metal-free naphthalene diimide-based covalent organic framework electrocatalyst

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    A novel naphthalene diimide-based covalent organic framework (NDI-COF) has been synthesized and successfully exfoliated into COF nanosheets (CONs). Electrochemical measurements reveal that the naphthalene diimide units incorporated into NDI-CONs act as efficient electrocatalyst for oxygen reduction in alkaline media, showing its potential for the development of metal-free fuel cellsFinancial support from the Spanish Government (projects MAT2016-77608-C3-1-P, MAT2016-77608-C3-2-P, CTQ2017-84309-C2-1-R, MAT2017-85089-C2-1-R, FJCI-2017-33536 and RYC-2015-17730), the UCM (INV.GR.00.1819.10759) and the Madrid Regional Government (TRANSNANOAVANSENS-CM (S2018/NMT-4349)) is acknowledge

    Programmed cell senescence during mammalian embryonic development

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    Cellular senescence disables proliferation in damaged cells, and it is relevant for cancer and aging. Here, we show that senescence occurs during mammalian embryonic development at multiple locations, including the mesonephros and the endolymphatic sac of the inner ear, which we have analyzed in detail. Mechanistically, senescence in both structures is strictly dependent on p21, but independent of DNA damage, p53, or other cell-cycle inhibitors, and it is regulated by the TGF-beta/SMAD and PI3K/FOXO pathways. Developmentally programmed senescence is followed by macrophage infiltration, clearance of senescent cells, and tissue remodeling. Loss of senescence due to the absence of p21 is partially compensated by apoptosis but still results in detectable developmental abnormalities. Importantly, the mesonephros and endolymphatic sac of human embryos also show evidence of senescence. We conclude that the role of developmentally programmed senescence is to promote tissue remodeling and propose that this is the evolutionary origin of damage-induced senescence

    Solution-Processed Ni-Based Nanocomposite Electrocatalysts: An Approach to Highly Efficient Electrochemical Water Splitting

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    In this study, we report an up-scalable and low-cost solution-processed method to in situ synthesize an earth-abundant non-stoichiometric NiOx-based electrocatalytic film for water oxidation. The catalytic activity was found to be inversely proportional to the baking temperature, which varied from 50 to 500 °C. We found the formation of a hybrid nanocomposite thin film of NiOx nanocrystals (<2 nm size) inside an acetate-based organic matrix at low temperatures (<200 °C). The defective and short-range structural order of the NiOx-based nanocomposite electrocatalysts, compatible with lattice stress, low electrical conductivity, and high density of catalytically active surface species, and higher Fe incorporation were responsible for the enhanced electrocatalytic activity. Our champion NiOx catalyst features a 358 mV overpotential at 10 mA cm–2 and more than 60 h of continuous operation without significant losses, which is a remarkable milestone for undoped NiOx electrocatalysts synthesized at nearly room temperature by a solution-processed up-scalable method.Funding for open access charge: CRUE-Universitat Jaume IThe authors acknowledge the financial support from the Ministerio de Ciencia, Innovación y Universidades of Spain through funded projects ENE2017-85087-C3-1-R, RYC-2015-18349, and TEC2017-86102-C2-1-R and Agencia Valenciana de la Innovacion (AVI) INNVAL10/18/032. The authors thank the Central Support Service for Experimental Research (SCSIE) (XRD and SEM facilities) and the Institute of Materials Science (TGA and DTA equipment) of the University of Valencia and the Central Service of Scientific Instrumentation (SCIC) at University Jaume I. The authors also thank Prof. Juan P. Martinez-Pastor for his constructive suggestions and scientific discussions

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Dimorfismo sexual en Microtus cabrerae en base a los caracteres de su pelvis.Notas sobre la distribución y ecología de Microtus cabreae, Thomas, 1906.Alimentación de la culebra bastarda (Malpolon monspessulanus, Ophidia, Colubridae) en el S. O. de España.Selectividad en la predación de la lechuza común (Tyto alba) sobre Rano ridibunda.Variations in the food habits of the european Eagle Owl. (Bubo bubo)Contaminación en huevos de aves silvestres de lSuroeste de España por residuos organoclorados (Insecticidas y bifenilos policlorados)Sobre el status taxonómico del águila imperial ibéricaEstudio filogenético y comparativo de Microtus cabrerae y Microtus brecciensisDescripción de una nueva especie de liebre (Lepus castroviejoi), endémica de la Cordillera CantábricaPeer reviewe

    EcoCyc: A comprehensive view of Escherichia coli biology

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    EcoCyc (http://EcoCyc.org) provides a comprehensive encyclopedia of Escherichia coli biology. EcoCyc integrates information about the genome, genes and gene products; the metabolic network; and the regulatory network of E. coli. Recent EcoCyc developments include a new initiative to represent and curate all types of E. coli regulatory processes such as attenuation and regulation by small RNAs. EcoCyc has started to curate Gene Ontology (GO) terms for E. coli and has made a dataset of E. coli GO terms available through the GO Web site. The curation and visualization of electron transfer processes has been significantly improved. Other software and Web site enhancements include the addition of tracks to the EcoCyc genome browser, in particular a type of track designed for the display of ChIP-chip datasets, and the development of a comparative genome browser. A new Genome Omics Viewer enables users to paint omics datasets onto the full E. coli genome for analysis. A new advanced query page guides users in interactively constructing complex database queries against EcoCyc. A Macintosh version of EcoCyc is now available. A series of Webinars is available to instruct users in the use of EcoCyc

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Datos sobre la fauna de anfibios del Bajo GuadalquivirDiet of the Black Vulture (Aegypius monachus) in the Iberian PeninsulaBiología de reproducción de una pareja de Hieraetus fasciatus en España central.Sobre la migraclon de la focha común (Fulica atra) en el Mediterráneo Occidental en base a la información de la Estación Biológica de laTour du Valat (Camargue, Francia)Problemática y medidas de conservación de la Foca fraile (Monachus monachus, Hermann 1779) en el Sahara OccidentaNuevas citas de sifonápteros parásitos de mamíferos en España.Contribución al estudio de Lacerta monticola en la Sierra de Gredos (Avila. España)A melanistic Spanish smooth snake (Coranella a. austriaca)Nueva localidad para Vipera b. berus en el. Norte de EspañaSegunda cita en España de Porphyrula alleni (Thomson, 1842)Peer reviewe

    Development of the preterm gut microbiome in twins at risk of necrotising enterocolitis and sepsis

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    The preterm gut microbiome is a complex dynamic community influenced by genetic and environmental factors and is implicated in the pathogenesis of necrotising enterocolitis (NEC) and sepsis. We aimed to explore the longitudinal development of the gut microbiome in preterm twins to determine how shared environmental and genetic factors may influence temporal changes and compared this to the expressed breast milk (EBM) microbiome. Stool samples (n = 173) from 27 infants (12 twin pairs and 1 triplet set) and EBM (n = 18) from 4 mothers were collected longitudinally. All samples underwent PCR-DGGE (denaturing gradient gel electrophoresis) analysis and a selected subset underwent 454 pyrosequencing. Stool and EBM shared a core microbiome dominated by Enterobacteriaceae, Enterococcaceae, and Staphylococcaceae. The gut microbiome showed greater similarity between siblings compared to unrelated individuals. Pyrosequencing revealed a reduction in diversity and increasing dominance of Escherichia sp. preceding NEC that was not observed in the healthy twin. Antibiotic treatment had a substantial effect on the gut microbiome, reducing Escherichia sp. and increasing other Enterobacteriaceae. This study demonstrates related preterm twins share similar gut microbiome development, even within the complex environment of neonatal intensive care. This is likely a result of shared genetic and immunomodulatory factors as well as exposure to the same maternal microbiome during birth, skin contact and exposure to EBM. Environmental factors including antibiotic exposure and feeding are additional significant determinants of community structure, regardless of host genetics
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