330 research outputs found
Flow micro-calorimetry and diffuse reflectance Fourier transform infrared spectroscopy studies in filled polyurethane adhesives by using dimethyl adipate as a model compound
Interactions between nano-scale filler particles (precipitated calcium carbonate, carbon black and fumed silica) and model compounds (dimethyl adipate and butan-2-one) are quantified using flow micro-calorimetry (FMC) and diffuse reflectance Fourier transform infrared spectroscopy (DRFTIRS). Carbonyl groups of dimethyl adipate interact strongly with silanol groups on the fumed silica surface but weakly with the uncoated precipitated calcium carbonate. In general, higher surface area loading imparts high level of adsorption because of the nanofiller has more adsorption sites. Carbon black is an exception likely due to the less accessible surface groups and the presence of relatively important amount of micropores. © 2013 Elsevier Ltd
Dietary regulation of VEGFb gene expression is related to its promoter DNA methylation levels
Motivación: Recientemente se ha descrito la implicación del factor de crecimiento del endotelio vascular B (VEGFb) en la absorción de los ácidos grasos (AGs) en los tejidos y su relación con el desarrollo de diferentes enfermedades metabólicas tal como la obesidad y la diabetes tipo 2. El objetivo de este estudio es investigar el efecto de la composición de los AGs de la dieta en la regulación de la expresión génica del VEGFb en los tejidos adiposos de rata, y si este efecto está relacionado mediante modificación por metilación del DNA en el promotor del VEGFb. De esta forma la modificación de la dieta puede ser una nueva estrategia para modular la acumulación patológica de los lípidos en la obesidad o en la diabetes. Métodos: A cada grupo de ratas fue asignado una de tres diferentes dietas isoenergéticas, cada una con una concentración diferente de AGs saturados, mono y poliinsaturados (dieta de aceite de coco, aceite de oliva y de girasol). Los animales fueron alimentados durante un mes. Las muestras de tejido adiposo visceral (VAT) y subcutáneo (SAT) se tomaron inmediatamente para estudios de metilación y expresión génica. También de estos tejidos se tomaron mediciones de la composición de los AGs de los triglicéridos y la acumulación total de los tejidos adiposos. Resultados: Ni los pesos de los animales ni de los depósitos adiposos ni la acumulación lípidica del tejido cambiaban con las dietas. La composición en AGs de ambos tejidos fue significativamente diferente en función de la dieta consumida(p <0,0001 para todos los AGs estudiados). El nivel de expresión del gen VEGFb se correlaciona directamente con la acumulación de lípidos de cada tejido y con la composición de AGs del tejido. En ambos tejidos, los niveles de expresión génica del VEGFb y de metilación del promotor fueron diferentes con respecto a la dieta consumida, estando la expresión génica y los niveles de metilación del promotor del VEGFb inversamente correlacionados. Los valores más altos de expresión génica, y los más bajos de metilación del promotor, se encontraron en las ratas alimentadas con la dieta rica en aceite de coco. Conclusiones: La expresión del gen Vegfb en el tejido adiposo se asocia con el aumento en la acumulación de grasa. El estudio presentado muestra que la expresión génica del Vegfb está regulada por los AGs de la dieta, y esta regulación está relacionada con el nivel de metilación de la región promotora del Vegfb
The use of fluoroproline in MUC1 antigen enables efficient detection of antibodies in patients with prostate cancer
A structure-based design of a new gene22ration tumor-associated glycopeptides with improved affinity against two anti-MUC1 antibodies is described. These unique antigens feature a fluorinated proline residue, such as a (4S)-4-fluoro-L-proline or 4,4-difluoroproline, at the most immunogenic domain. Binding assays using bio-layer interferometry reveal 3-fold to 10-fold affinity improvement with respect to the natural (glyco)peptides. According to X-ray crystallography and MD simulations, the fluorinated residues stabilize the antigen-antibody complex by enhancing key CH/ interactions. Interestingly, a notable improvement in detection of cancer-associated anti-MUC1 antibodies from serum of patients with prostate cancer is achieved with the non-natural antigens, which proves that these derivatives can be considered better diagnostic tools than the natural antigen for this type of cancer.We thank the Ministerio de Economía y Competitividad (projects CTQ2015-67727-R, UNLR13-4E-1931, CTQ2013-44367-C2-2-P, CTQ2015-64597-C2-1P, and BFU2016-75633-P). I. A. B. thanks the Asociación Española Contra el Cancer en La Rioja for a grant. I. S. A. and G. J. L. B. thank FCT Portugal (PhD studentship and FCT Investigator, respectively) and the EPSRC for funding. G. J. L. B. holds a Royal Society URF and an ERC StG (TagIt). F.C. and G. J. L. B thank the EU (Marie-Sklodowska Curie ITN, Protein Conjugates). R.H-G. thanks Agencia Aragonesa para la Investigación y Desarrollo (ARAID) and the Diputación General de Aragón (DGA, B89) for financial support. The research leading to these results has also received funding from the FP7 (2007-2013) under BioStruct-X (grant agreement N°283570 and BIOSTRUCTX_5186). We thank synchrotron radiation source DIAMOND (Oxford) and beamline I04 (number of experiment mx10121-19). Hokkaido University group acknowledges to JSPS KAKENHI Grant Number 25220206 and JSPS Wakate B KAKENHI Grant Number 24710242. We also thank CESGA (Santiago de Compostela) for computer support
Mixed-method tutoring support improves learning outcomes of veterinary students in basic subjects
P. 1-10Tutoring is a useful tool in the university teaching-learning binomial, although its development is impaired
in large classes. Recent improvements in information and communication technologies have made tutoring possible via
the Internet. The aim of this study was to evaluate the efficacy of mixed-method academic tutoring in two basic subjects
in Veterinary Science studies at the University of León (Spain) to optimize the usefulness of tutoring support
in the college environment. This quasi-experimental study was firstly carried out as a pilot study in a small
group of tutored students of “Cytology and Histology” (CH) (47/186; 25.3%) and “Veterinary Pharmacology”
(VP) (33/141; 23.4%) subjects, and was implemented in a large class of CH the next academic year (150 students) while
comparing the results with those obtained in a previous tutorless course (162 students). Tutored students were given
access to online questionnaires with electronic feedback on each subject. In addition to traditional tutoring carried out
in both tutored and tutorless students, the pilot study included three sessions of face-to-face tutoring in order to monitor
the progress of students. Its efficacy was assessed by monitoring students’ examination scores and attendance as well as
a satisfaction survey.
Online tutoring support, together with conventional teaching methods, may be a useful method
to incorporate student-centered learning in basic subjects in Veterinary Science.S
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Demonstration of the event identification capabilities of the NEXT-White detector
In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies. [Figure not available: see fulltext.
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Radiogenic backgrounds in the NEXT double beta decay experiment
Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Qββ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events. [Figure not available: see fulltext.]
HARMONI- the Extremely Large Telescope first light integral field spectrograph: a novel control architecture to integrate the science instrument control system with that of adaptive optics
Pyrolysed almond shells used as electrodes in microbial electrolysis cell
9 p.The large cost of components used in microbial electrolysis cell (MEC) reactors represents an important limitation that is delaying
the commercial implementation of this technology. In this work, we explore the feasibility of using pyrolysed almond shells (PAS)
as a material for producing low-cost anodes for use in MEC systems. This was done by comparing the microbial populations that
developed on the surface of PAS bioanodes with those present on the carbon felt (CF) bioanodes traditionally used in MECs. Raw
almond shells were pyrolysed at three different temperatures, obtaining the best conductive material at the highest temperature
(1000 °C). The behaviour of this material was then verified using a single-chamber cell. Subsequently, the main test was carried out using two-chamber cells and the microbial populations extant on each of the bioanodes were analysed. High-throughput sequencing of the 16S rRNA gene for eubacterial populations was carried out in order to compare the microbial communities attached to each type of electrode. The microbial populations on each electrode were also quantified by real-time polymerase chain reaction (realtime PCR) to determine the amount of bacteria capable of growing on the electrodes’surface. The results indicated that the newly developed PAS bioanodes possess a biofilm similar to those found on the surface of traditional CF electrodes.
This research was possible thanks to the financial support of the Junta de Castilla y León, and was financed by European Regional Development Funds (LE320P18). C. B. thanks the Spanish Ministerio de Educación, Cultura y Deporte for support in the form of an FPI fellowship grant (Ref #: BES-2016-078329)
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Energy calibration of the NEXT-White detector with 1% resolution near Q ββ of 136Xe
Excellent energy resolution is one of the primary advantages of electroluminescent high-pressure xenon TPCs. These detectors are promising tools in searching for rare physics events, such as neutrinoless double-beta decay (ββ0ν), which require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for ββ0ν searches. [Figure not available: see fulltext.
Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and
Technology (CICYT), the
Spanish National Parks agency, the European Commission, the
Spanish Ministry of Science, and the European
Social Fund
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