128 research outputs found

    Fiber-Optic-Based System for High-Resolution Monitoring of Stretch in Excised Tissues

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    Cardiovascular diseases cause a high number of deaths nowadays. To improve these statistics, new strategies to better understand the electrical and mechanical abnormalities underlying them are urgently required. This study focuses on the development of a sensor to measure tissue stretch in excised tissues, enabling improved knowledge of biomechanical properties and allowing greater control in real time. A system made of biocompatible materials is described, which is based on two cantilevered platforms that integrate an optical fiber inside them to quantify the amount of stretch the tissues are exposed to with a precision of μm. The operating principle of the sensor is based on the variation of the optical path with the movement of the platforms onto which the samples are fixed. The conducted tests highlight that this system, based on a simple topology and technology, is capable of achieving the desired purpose (a resolution of ∼1 μm), enabling the tissue to be bathed in any medium within the system

    Diseño y simulación para la automatización de los procesos de sellado y lacado, en la línea de fabricación de dormitorios de la empresa Carpintería y Tapicería Internacional CTIN. CIA. LTDA.

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    Este documento detalla sobre la automatización de los procesos de sellado y lacado para la empresa Carpintería y Tapicería Internacional, donde se realiza pruebas de laboratorios y una investigación de las tecnologías en función de los muebles que se producen en la línea de dormitorios, con el fin de obtener el mejor sistema que se adapte a la planta actual, el cual es el sistema con robot de configuración cartesiana de cinco grados de libertad.This document is about the automation of sealing and lacquering process of the "Carpintería y Tapicería Internacional" company, where you can find laboratory tests and a research about technology in function of the furniture which is produced in the bedroom line, with the final purpose of get the best system that adapts to the current production, which is the cartesian robot with five degree of freedom

    Solid Multiresponsive Materials Based on Nitrospiropyran-Doped Ionogels

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    Altres ajuts: Acord transformatiu CRUE-CSICThe application of molecular switches for the fabrication of multistimuli-responsive chromic materials and devices still remains a challenge because of the restrictions imposed by the supporting solid matrices where these compounds must be incorporated: they often critically affect the chromic response as well as limit the type and nature of external stimuli that can be applied. In this work, we propose the use of ionogels to overcome these constraints, as they provide a soft, fluidic, transparent, thermally stable, and ionic-conductive environment where molecular switches preserve their solution-like properties and can be exposed to a number of different stimuli. By exploiting this strategy, we herein pioneer the preparation of nitrospiropyran-based materials using a single solid platform that exhibit optimal photo-, halo-, thermo-, and electrochromic switching behaviors

    Solid Multiresponsive Materials Based on Nitrospiropyran-Doped Ionogels

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    Altres ajuts: acords transformatius de la UABThe application of molecular switches for the fabrication of multistimuli-responsive chromic materials and devices still remains a challenge because of the restrictions imposed by the supporting solid matrices where these compounds must be incorporated: they often critically affect the chromic response as well as limit the type and nature of external stimuli that can be applied. In this work, we propose the use of ionogels to overcome these constraints, as they provide a soft, fluidic, transparent, thermally stable, and ionic-conductive environment where molecular switches preserve their solution-like properties and can be exposed to a number of different stimuli. By exploiting this strategy, we herein pioneer the preparation of nitrospiropyran-based materials using a single solid platform that exhibit optimal photo-, halo-, thermo-, and electrochromic switching behaviors

    A rapid and versatile microfluidic method for the simultaneous extraction of polar and non-polar basic pharmaceuticals from human urine

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    In sample preparation, simultaneous extraction of analytes of very different polarity from biological matrixes represents a challenge. In this work, verapamil hydrochloride (VRP), amitriptyline (AMP), tyramine (TYR), atenolol (ATN), metopropol (MTP) and nortriptyline (NRP) were used as basic model analytes and simultaneously extracted from urine samples by liquid-phase microextraction (LPME) in a microfluidic device. The model analytes (target compounds) were pharmaceuticals with 0.4 < log P < 5. Different organic solvents and mixtures of them were investigated as supported liquid membrane (SLM), and a mixture of 2:1 (v/v) tributyl phosphate (TBP) and dihexyl ether (DHE) was found to be highly efficient for the simultaneous extraction of the non-polar and polar model analytes. TBP reduced the intrinsic hydrophobicity of the SLM and facilitated extraction of polar analytes, while DHE served to minimize trapping of non-polar analytes. Sample and acceptor phase composition were adjusted to pH 12 and pH 1.5, respectively. Urine samples were pumped into the microfluidic system at 1 μL min-1 and the extraction was completed in 7 min. Recoveries exceeded 78% for the target analytes, and the relative standard deviation (n = 4) was below 7% in all cases. Using five microliters of SLM, the microfluidic extraction system showed good long-term stability, and the same SLM was used for more than 18 consecutive extractions.Agencia de Gestió d'Ajusts Universitaris i the Recerca 2017-SGR-329Ministerio de Ciencia e Innovación PGC2018-096608-B-C2

    Oxidative dissolution mechanism of both undoped and Gd2O3-doped UO2(s) at alkaline to hyperalkaline pH†

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    The dissolution rates of unirradiated UO2 and unirradiated UO2 doped with Gd2O3 were determined as a function of pH using flow-through experiments in the presence of O2(g) and bicarbonate. The dissolution rate of non-doped UO2 was very low under hyperalkaline conditions (pH 12–13) whereas it increased drastically as the pH decreased to 9. The dissolution of non-doped UO2 in the pH range of 9–13 was consistent with the oxidative dissolution mechanism already described for UO2 dissolution in the presence of bicarbonate and oxygen. XPS analysis performed on the solid after dissolution experiments at pH 10 and 13 supported the bicarbonate effect to complex UO22+ and accelerate dissolution. Moreover, UO2 doped with Gd2O3 (5 wt% and 10 wt%) showed dissolution rates as low as non-doped UO2 under hyperalkaline conditions, which were maintained throughout the pH range studied (9–13). No substantial differences in the dissolution rates between these two doping levels were found. XPS analysis evidenced a similar surface composition both at pH 10 and 13, with U(V) being the dominant oxidation state. The low dissolution rates were assumed to be a consequence of the gadolinium capacity to retard the oxidation of U(V) to U(VI). The slight increase in dissolution rates observed in the hyperalkaline region was attributed to a shift in the oxidative dissolution mechanism, in which the presence of OH- promotes the formation of soluble uranyl hydroxo complexes.Peer ReviewedPostprint (published version

    Portable Electronic Tongue Based on Microsensors for the Analysis of Cava Wines

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    Cava is a quality sparkling wine produced in Spain. As a product with a designation of origin, Cava wine has to meet certain quality requirements throughout its production process; therefore, the analysis of several parameters is of great interest. In this work, a portable electronic tongue for the analysis of Cava wine is described. The system is comprised of compact and low-power-consumption electronic equipment and an array of microsensors formed by six ion-selective field effect transistors sensitive to pH, Na+, K+, Ca2+, Cl−, and CO32−, one conductivity sensor, one redox potential sensor, and two amperometric gold microelectrodes. This system, combined with chemometric tools, has been applied to the analysis of 78 Cava wine samples. Results demonstrate that the electronic tongue is able to classify the samples according to the aging time, with a percentage of correct prediction between 80% and 96%, by using linear discriminant analysis, as well as to quantify the total acidity, pH, volumetric alcoholic degree, potassium, conductivity, glycerol, and methanol parameters, with mean relative errors between 2.3% and 6.0%, by using partial least squares regressions.We acknowledge funding from the Spanish R & D National Program (MINECO, Projects TEC2011-29045-C04-01 and TEC2014-54449-C3-1-R). P.G.-G. is grateful to MINECO, Spain, for the financial support through a research studentship of the FPI Program. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)

    Compact analytical flow system for the simultaneous determination of L-lactic and L-malic in red wines

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    During the malolactic fermentation of red wines, L-malic acid is mainly converted to L-lactic acid. Both acids should be precisely measured during the entire process to guarantee the quality of the final wine, thus making real-time monitoring approaches of great importance in the winemaking industry. Traditional analytical methods based on laboratory procedures are currently applied and cannot be deployed on-site. In this work, we report on the design and development of a bi-parametric compact analytical flow system integrating two electrochemical biosensors that could be potentially applied in this scenario. The developed flow-system will allow for the first time the simultaneous measurement of both acids in real scenarios at the real-time and in remote way. Miniaturized thin-film platinum four-electrode chips are fabricated on silicon substrates by standard photolithographic techniques and further implemented in a polymeric fluidic structure. This includes a 15 µL flow cell together with the required fluidic channels for sample and reagent fluid management. The four-electrode chip includes counter and pseudo-reference electrodes together with two working electrodes. These are sequentially modified with electropolymerized polypyrrole membranes that entrap the specific receptors for selectively detecting both target analytes. The analytical performance of both biosensors is studied by chronoamperometry, showing a linear range from 5 × 10−6 to 1 × 10−4 M (LOD of 3.2 ± 0.3 × 10−6 M) and from 1 × 10−7 to 1 × 10−6 M (LOD of 6.7 ± 0.2 × 10−8 M) for the L-lactate and the L-malate, respectively. Both biosensors show long-term stability, retaining more than the 90% of their initial sensitivity after more than 30 days, this being a prerequisite for monitoring the whole process of the malolactic fermentation of the red wines (time between 20 and 40 days). The flow system performance is assessed with several wine samples collected during the malolactic fermentation process of three red wines, showing an excellent agreement with the results obtained with the standard method.info:eu-repo/semantics/publishedVersio

    A novel integrated platform enabling simultaneous microextraction and chemical analysis on-chip

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    Altres ajuts: acords transformatius de la UABThe nature and size of biological, pharmaceutical or environmental analytes complicates their extraction and detection outside of laboratories and near the site of interest by the current chromatographic methods because they require the combination of bulky extraction and detection methods. In order to solve this inefficient centralized control, a ground-breaking and miniaturized proof of concept platform is developed in this work. The platform integrates for the very first time an electro-membrane extraction process and an accurate analyte quantification method in the same device, by using electrochemical impedance spectroscopy (EIS) as analytical technique. The microfluidic flow cell, including the microfluidic components, is fabricated in polymeric materials by rapid prototyping techniques. It comprises a four-electrode platinum thin-film chip that enables the control of the microextraction and the full characterization of the process, i.e., extraction efficiency determination, at the same time. The microfluidic system has been simulated by using computational tools, enabling an accurate prediction of the effect of the different experimental conditions in the microextraction efficiency. The platform has been validated in the microextraction of the nonsteroidal anti-inflammatory drug ketoprofen in a range from 0.5 ppm to 6 ppm. The predicted microextraction efficiency values obtained by EIS were compared with those calculated from the high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), showing an excellent agreement. This validates the high potential of this integrated and miniaturized platform for the simultaneous extraction by electro-membrane and also the analysis within the platform, solving one of the of most important limitations of current systems

    Spectroelectrochemical studies of electrochromic diarylethene ionic Liquids : From solution to ionogel based devices

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    Acord transformatiu CRUE-CSICThis study establishes the photoelectrochromic properties of four diarylethene ionic liquids (DAE-ILs) composed of a diarylethene dicarboxylate (DAE) moiety, as counter-anion, and different organic cations ([Cmim], [CPyr] , [N], [P]). The synthetized ILs viscous fluids maintain the photochemical and electrochemical properties of this well-known family of photoswitches, as well as the typical features of ILs (e.g., low melting point, and high thermal and electrochemical stability). Our strategy of making multi-stimuli-responsive ionic liquids by ionic exchange opens the door to easily tune the physicochemical properties of smart DAE-ILs in function of the selected cation. Finally, those DAE-ILs are used to formulate smart ionogels (IGs), a type of materials that, by showing good conductive properties and retaining the stimuli-responsive behavior of the embedded DAE molecules, allow the fabrication of photoelectrochemical devices
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