1,034 research outputs found

    The design and characterisation of sol–gel coatings for the controlled-release of active molecules

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    The controlled release of active agents from a matrix has become increasingly important for oral, transdermal or implantable therapeutic systems, due to the advantages of safety, efficacy and patient convenience. Controlled-release hybrid (organic-inorganic) sol-gel coating synthesis has been performed to create a sol with an active molecule included (procaine). Synthesis procedures included acid-catalysed hydrolysis, sol preparation, the addition of a procaine solution to the sol, and the subsequent gelation and drying. The alkoxide precursors used were triethoxyvinylsilane and tetraethyl-orthosilicate (TEOS) in molar ratios of 1:0, 9:1, 8:2 and 7:3. After the determination of the optimal synthesis parameters, the material was physicochemically characterised by silicon-29 nuclear magnetic resonance (²⁹Si-NMR) and Fourier transform infrared spectroscopy, contact angle analysis and electrochemical impedance spectroscopy tests. Finally, the materials were assayed in vitro for their ability to degrade by hydrolysis and to release procaine in a controlled manner. The sustained release of procaine over a 3-day period was demonstrated. A close correlation between release and degradation rates suggests that film degradation is the main mechanism underlying the control of release. Electrochemical analysis reveals the formation of pores and water uptake during the degradation. The quantity of TEOS is one of the principal parameters used to determine the kinetics of degradation and procaine release.The supports of the Spanish Ministry of Economy and Competitiveness through project IPT-010000-2010-004 and of the University of the Basque Country (UPV/EHU) through ‘‘UFI11/56’’ are kindly acknowledge

    The Bulgeless Seyfert/LINER Galaxy NGC 3367: Disk, Bar, Lopsidedness and Environment

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    NGC3367 is a nearby isolated active galaxy that shows a radio jet, a strong bar and evidence of lopsidedness. We present a quantitative analysis of the stellar and gaseous structure of the galaxy disk and a search for evidence of recent interaction based on new UBVRI Halpha and JHK images and on archival Halpha Fabry-Perot and HI VLA data. From a coupled 1D/2D GALFIT bulge/bar/disk decomposition an (B/D ~ 0.07-0.1) exponential pseudobulge is inferred in all the observed bands. A NIR estimate of the bar strength = 0.44 places NGC 3367 bar among the strongest ones. The asymmetry properties were studied using (1) optical and NIR CAS indexes (2) the stellar (NIR) and gaseous (Halpha, HI) A_1 Fourier mode amplitudes and (3) the HI integrated profile and HI mean intensity distribution. While the average stellar component shows asymmetry values close to the average found in the Local Universe for isolated galaxies, the young stellar component and gas values are largely decoupled showing significantly larger A_1 mode amplitudes suggesting that the gas has been recently perturbed. Our search for (1) faint stellar structures in the outer regions (up to u_R ~ 26 mag arcsec^{-2}), (2) (Halpha) star-forming satellite galaxies and (3) regions with different colors (stellar populations) along the disk all failed. Such an absence is interpreted using recent numerical simulations to constrain a tidal event with an LMC like galaxy to some dynamical times in the past or to a current very low mass, gas rich accretion. We conclude that a cold accretion mode (gas and small/dark galaxies) may be responsible of the nuclear activity and peculiar (young stars and gas) morphology regardless of the highly isolated environment. Black hole growth in bulgeless galaxies may be triggered by cosmic smooth mass accretion.Comment: 27 pages, 12 figures, accepted for publication in The Astronomical Journa

    Optical spectroscopic study of the growth dynamics of radio-frequency-sputtered YBa2Cu3O(7-x) thin films

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    An optical spectroscopic study of the plasma produced during rf sputtering of an YBa2Cu3O7-x target was performed to analyze two basic properties of the deposition process: resputtering effects and oxidation mechanisms. Strong emissions of all the species above a value of the target voltage were found. These observations are associated to a strong secondary electron emission of the target which originates a negative self-bias of the substrate and a subsequent resputtering by argon cations. The addition of different amounts of oxygen to the discharge reveals that preoxidation in the gas phase may decrease the oxygen content in the films: the oxidation of the films is dominated by atomic oxygen

    Las características del desayuno en alumnos de educación obligatoria

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    The aim of this study was to determine the breakfast of compulsory education students (time, type of food, company). The sample consisted of 345 subjects, 223 students of third cycle primary and 122 students of second cycle of ESO. The instrument used for data collection was a questionnaire on the characteristics breakfast. The results show that children / as primary graduate breakfast better than children / as second cycle of ESO. Following this line of breakfast children better than girls at the stage of compulsory education. The average time for breakfast is 9 minutes and 31 seconds to make it a favorite place is in the kitchen accompanied by parents and siblings.El objetivo del presente estudio fue conocer las características del desayuno de los alumnos de educación obligatoria (tiempo, tipo de alimentos, compañía). La muestra estuvo compuesta por 345 sujetos, 223 alumnos de tercer ciclo de primaria y 122 alumnos de segundo ciclo de la E.S.O. El instrumento utilizado para la recogida de datos fue un cuestionario sobre las características del desayuno. Los resultados muestran que los niños/as de tercer ciclo de primaria desayunan mejor que los niños/as de segundo ciclo de la E.S.O. Siguiendo esta línea los niños desayunan mejor que las niñas en la etapa de educación obligatoria. El tiempo medio dedicado al desayuno es de 9 minutos y 31 segundos. El sitio preferido para hacerlo es en la cocinaacompañados por los padres y hermanos

    Cambios morfométricos de lagunas aluviales del río Paraná y su incidencia en la diversidad íctica

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    Para comprender cuáles son las características ambientales que inciden en las comunidades acuáticas de una laguna, es necesario poseer conocimientos referidos a sus formas y dimensiones, ya que su morfometría interviene sobre variables relacionadas con la erosión, sedimentación, carga de nutrientes y características físico-químicas, entre otras. Sin embargo, la renovación del agua de las lagunas del valle aluvial se encuentra íntimamente ligada a los pulsos de inundación de este último, entendiéndose que es tanimportante la altura del nivel de agua, como su duración en el tiempo. Diferentes nivelestopográficos de la llanura aluvial, pueden generar distintas respuestas en las lagunas, al margen de encontrarse próximas entre ellas. En tal sentido, el objetivo de este trabajo fue aplicar modelos de anegamiento en la llanura aluvial del río Paraná, a fin de establecer las diferencias topográficas entre las lagunas Galloso y Melilla, para explicar sus respuestas frente a los pulsos de inundación y por consiguiente sus diferencias morfométricas y biológicas. Para ello se utilizó la herramienta Increase level water del software Global Mapper 15.1, teniendo como base un modelo de elevación digital generado a partir de una imagen SRTM de 30 m. Los resultados demostraron que la laguna Galloso se encuentra 2 m por debajo de la laguna Melilla, quedando más expuesta a los pulsos de inundación del río Paraná. Dicha situación se ve reflejada en sus variaciones morfométricas entre los años estudiados, en donde la laguna Galloso ha aumentado 19 veces su superficie mientras que la laguna Melilla se mantuvo estable. En conclusión, esta diferencia topográfica y la mayor conectividad con el río Paraná, sería el principal motivo por el cual la primera posee 80 especies de peces, mientras que lasegunda solo 49 especies

    Using radio astronomical receivers for molecular spectroscopic characterization in astrochemical laboratory simulations: A proof of concept

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    We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactorsand the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40\,cm long gas cell placed in the beam path of the Aries 40\,m radio telescope receivers operating in the 41-49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH3OH, CH3CH2OH, HCOOH, OCS,CS, SO2 (<1E-03 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O2 and CS2 was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.Comment: Accepted for publication in Astronomy and Astrophysics in September 21, 2017. 16 pages, 18 figure

    Stimulated Raman Scattering for All Optical Switches

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    We theoretically and experimentally investigate an all optical switch based on stimulated Raman scattering in optical fibers. The experimental setup consists of a Raman circuit of two stages connected in series through a bandpass filter. In the first stage, we have a saturated amplifier, in this stage the pump pulses are saturated when pump and signal are launched to the input or the pump pulses remain without saturation when pump only is launched at the input. The second stage works as the Raman amplifier; for this stage amplification is directly dependent on the pump power entering from the first stage. For the case when pump pulse only is launched at the input pass to the second stage without saturation and amplifies the signal entering in the second stage, very intense signal pulses appear at the output of this stage. For the case when both pump and signal pulses are launched to the input, the pump pulse is saturated in the first stage and the filter rejected the amplified signal, so that only low power pump enters the second stage and consequently no signal pulses appear at the output. We show that the contrast can be improved when using fibers with normal and anomalous dispersion connected in series in the first stage. The best contrast (the ratio of energies) obtained was 15 dB at 6 W pump peak power

    Huntington's disease-specific mis-splicing unveils key effector genes and altered splicing factors

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    Correction of mis-splicing events is a growing therapeutic approach for neurological diseases such as spinal muscular atrophy or neuronal ceroid lipofuscinosis 7, which are caused by splicing-affecting mutations. Mis-spliced effector genes that do not harbour mutations are also good candidate therapeutic targets in diseases with more complex aetiologies such as cancer, autism, muscular dystrophies or neurodegenerative diseases. Next-generation RNA sequencing (RNA-seq) has boosted investigation of global mis-splicing in diseased tissue to identify such key pathogenic mis-spliced genes. Nevertheless, while analysis of tumour or dystrophic muscle biopsies can be informative on early stage pathogenic mis-splicing, for neurodegenerative diseases, these analyses are intrinsically hampered by neuronal loss and neuroinflammation in post-mortem brains. To infer splicing alterations relevant to Huntington's disease pathogenesis, here we performed intersect-RNA-seq analyses of human post-mortem striatal tissue and of an early symptomatic mouse model in which neuronal loss and gliosis are not yet present. Together with a human/mouse parallel motif scan analysis, this approach allowed us to identify the shared mis-splicing signature triggered by the Huntington's disease-causing mutation in both species and to infer upstream deregulated splicing factors. Moreover, we identified a plethora of downstream neurodegeneration-linked mis-spliced effector genes that-together with the deregulated splicing factors-become new possible therapeutic targets. In summary, here we report pathogenic global mis-splicing in Huntington's disease striatum captured by our new intersect-RNA-seq approach that can be readily applied to other neurodegenerative diseases for which bona fide animal models are available.Extremadura Research Centre for Advanced Technologies (CETA-CIEMAT), funded by the European Regional Development Fund (ERDF). CETA-CIEMAT belongs to CIEMAT and the Government of Spai

    Optical properties of polycrystalline Cd(1-x)Mn(x)Te

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    Bulk polycrystalline cadmium manganese telluride, Cd(l-x)Mn(x)Te, was manufactured in several compositions by a synthesis process. The structure of the obtained compounds was the characteristic zinc-blende polycrystalline pattern being the grain size lOOj=20 nm. These materials are manufactured to replace single-crystal compounds in some magneto-optical devices. The cut-off wavelength and the Verdet constant are the same as the single-crystals with identical composition. A polarized laser beam, after having passed through a sample of 0.76 mm thickness, was depolarized less than 2.5%, and 90% of its energy was spread into a 2º cone. Scattering of light is produced because of the polycrystalline structure of these ompounds. Some scattering diagrams, due to the diffraction and Mie scattering in the polycrystalline grains are shown
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