64 research outputs found

    Finding the Additives Incorporation Moment in Hybrid Natural Pigments Synthesis to Improve Bioresin Properties

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    [EN] Interest in applications of natural dye applications has increased because of their antibacterial properties and the possibility of extracting them from nature and residues. Using nanoclays as hosts to reinforce natural dye properties has been successfully demonstrated. However, no one has attempted to optimize the polymer matrix and hybrid pigment properties at the same time to ensure the best final properties for bio-composite applications. Using a statistical design for experiments, we propose the best combination of modifiers with the best nanoclay as the host of three natural dyes: chlorophyll, ß-carotene, and betanine. Using the L9 Taguchi designs, we learned both the influence of the nanoclay structure, and the addition moment of surfactant, mordant salt, and silane modifiers. FTIR, XRD, DTG, integration sphere spectrophotometer, and UV-aging tests were used to characterize the hybrid pigments and epoxy bioresin composites. The degradation temperatures of the three natural dyes rose and the reinforcement of the stability of three natural dyes to UV¿Vis radiation exposure was demonstrated, which avoided the migration of these dyes from bioresin to wet ribbing. Optimal results were obtained with hydrotalcite clay (calcined or not) by using surfactant and mordant before the natural dye, and before or after silane. View Full-TextThis research was funded by Spanish Agencia Estatal de Investigacion (AEI) and the European Union (FEDER funds) (contract MAT2016-77742-C2-1-P) and Spanish Ministry of Economy and Competitiveness (project DPI2015-65814-R).Micó-Vicent, B.; Jordán Núñez, J.; Perales Romero, E.; Martínez-Verdú, FM.; Cases, F. (2019). Finding the Additives Incorporation Moment in Hybrid Natural Pigments Synthesis to Improve Bioresin Properties. Coatings. 9(1):1-17. https://doi.org/10.3390/coatings9010034S11791Rather, L. J., Shahid-ul-Islam, Shabbir, M., Bukhari, M. N., Shahid, M., Khan, M. A., & Mohammad, F. (2016). Ecological dyeing of Woolen yarn with Adhatoda vasica natural dye in the presence of biomordants as an alternative copartner to metal mordants. Journal of Environmental Chemical Engineering, 4(3), 3041-3049. doi:10.1016/j.jece.2016.06.019Kilinc, M., Canbolat, S., Merdan, N., Dayioglu, H., & Akin, F. (2015). Investigation of the Color, Fastness and Antimicrobial Properties of Wool Fabrics Dyed with the Natural Dye Extracted from the Cone of Chamaecyparis Lawsoniana. Procedia - Social and Behavioral Sciences, 195, 2152-2159. doi:10.1016/j.sbspro.2015.06.281Chiari, G., Giustetto, R., Druzik, J., Doehne, E., & Ricchiardi, G. (2007). Pre-columbian nanotechnology: reconciling the mysteries of the maya blue pigment. Applied Physics A, 90(1), 3-7. doi:10.1007/s00339-007-4287-zMicó-Vicent, B., Martínez-Verdú, F. M., Novikov, A., Stavitskaya, A., Vinokurov, V., Rozhina, E., … Lvov, Y. (2017). Stabilized Dye-Pigment Formulations with Platy and Tubular Nanoclays. Advanced Functional Materials, 28(27), 1703553. doi:10.1002/adfm.201703553Kohno, Y., Inagawa, M., Ikoma, S., Shibata, M., Matsushima, R., Fukuhara, C., … Kobayashi, K. (2011). Stabilization of a hydrophobic natural dye by intercalation into organo-montmorillonite. Applied Clay Science, 54(3-4), 202-205. doi:10.1016/j.clay.2011.09.001Kohno, Y., Asai, S., Shibata, M., Fukuhara, C., Maeda, Y., Tomita, Y., & Kobayashi, K. (2014). Improved photostability of hydrophobic natural dye incorporated in organo-modified hydrotalcite. Journal of Physics and Chemistry of Solids, 75(8), 945-950. doi:10.1016/j.jpcs.2014.04.010Sanchez-Garcia, M. D., Lopez-Rubio, A., & Lagaron, J. M. (2010). Natural micro and nanobiocomposites with enhanced barrier properties and novel functionalities for food biopackaging applications. Trends in Food Science & Technology, 21(11), 528-536. doi:10.1016/j.tifs.2010.07.008Micó-Vicent, B., Jordán, J., Martínez-Verdú, F., & Balart, R. (2016). A combination of three surface modifiers for the optimal generation and application of natural hybrid nanopigments in a biodegradable resin. Journal of Materials Science, 52(2), 889-898. doi:10.1007/s10853-016-0384-8Pérez-Ramírez, J., Abelló, S., & van der Pers, N. M. (2007). Memory Effect of Activated Mg–Al Hydrotalcite: In Situ XRD Studies during Decomposition and Gas-Phase Reconstruction. Chemistry - A European Journal, 13(3), 870-878. doi:10.1002/chem.200600767Sommer, A., Romero, A., Fetter, G., Palomares, E., & Bosch, P. (2013). Exploring and tuning the anchorage of chlorophyllin molecules on anionic clays. Catalysis Today, 212, 186-193. doi:10.1016/j.cattod.2013.03.014Ma, Y., Zhu, J., He, H., Yuan, P., Shen, W., & Liu, D. (2010). Infrared investigation of organo-montmorillonites prepared from different surfactants. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 76(2), 122-129. doi:10.1016/j.saa.2010.02.038Liu, D., Yuan, P., Liu, H., Cai, J., Tan, D., He, H., … Chen, T. (2013). Quantitative characterization of the solid acidity of montmorillonite using combined FTIR and TPD based on the NH3 adsorption system. Applied Clay Science, 80-81, 407-412. doi:10.1016/j.clay.2013.07.006Serratos, I. N., Rojas-González, F., Sosa-Fonseca, R., Esparza-Schulz, J. M., Campos-Peña, V., Tello-Solís, S. R., & García-Sánchez, M. A. (2013). Fluorescence optimization of chlorophyll covalently bonded to mesoporous silica synthesized by the sol–gel method. Journal of Photochemistry and Photobiology A: Chemistry, 272, 28-40. doi:10.1016/j.jphotochem.2013.08.014İnanç Horuz, T., & Belibağlı, K. B. (2018). Nanoencapsulation by electrospinning to improve stability and water solubility of carotenoids extracted from tomato peels. Food Chemistry, 268, 86-93. doi:10.1016/j.foodchem.2018.06.017Selvi, J. A., Rajendran, S., Sri, V. G., Amalraj, A. J., & Narayanasamy, B. (2009). Corrosion Inhibition by Beet Root Extract. Portugaliae Electrochimica Acta, 27(1), 1-11. doi:10.4152/pea.200901001Xie, W., Gao, Z., Pan, W.-P., Hunter, D., Singh, A., & Vaia, R. (2001). Thermal Degradation Chemistry of Alkyl Quaternary Ammonium Montmorillonite. Chemistry of Materials, 13(9), 2979-2990. doi:10.1021/cm010305

    Validação intercultural em português de um questionário para avaliar a síndrome visual do computador em trabalhadores expostos a dispositivos digitais

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    Purpose: As digital devices are increasingly used at work, valid and reliable tools are needed to assess their effect on visual health. This study aimed to translate, cross-culturally adapt, and validate the Computer Vision Syndrome Questionnaire (CVS-Q©) into Portuguese. Methods: A 5-phase process was followed: direct translation, synthesis of translation, back-translation, consolidation by an expert committee, and pretest. To run the pretest, a cross-sectional pilot study was conducted with 26 participants who completed the prefinal Portuguese version of the CVS-Q© and were asked about difficulties, comprehensibility, and suggestions to improve the questionnaire. To evaluate the reliability and validity of the Portuguese version of the CVS-Q©, a cross-sectional validation study was performed in a different sample (280 workers). Results: In the pretest, 96.2% had no difficulty in completing it, and 84.0% valued it as clear and understandable. CVS-Q© in Portuguese (Questionário da Síndrome Visual do Computador, CVS-Q PT©) was then obtained. Validation revealed the scale’s good internal consistency (Cronbach’s alpha=0.793), good temporal stability (intraclass correlation coefficient=0.847; 95% CI 0.764-0.902, kappa=0.839), adequate sensitivity and specificity (78.5% and 70.7%, respectively), good discriminant capacity (area under the curve=0.832; 95% CI 0.784-0.879), and adequate convergent validity with the ocular surface disease index (Spearman correlation coefficient=0.728, p<0.001). The factor analysis provided a single factor accounting for 37.7% of the explained common variance. A worker who scored ≥7 points would have computer vision syndrome. Conclusions: CVS-Q PT© can be considered an intuitive and easy-to-understand tool with good psychometric properties to measure computer vision syndrome in Portuguese workers exposed to digital devices. This questionnaire will assist in making decisions on preventive measures, interventions, and treatment and comparing exposed populations in different Portuguese-speaking countries.Objetivos: À medida que a utilização de equipamentos digitais no emprego aumenta, a avaliação do seu efeito na saúde visual necessita de ferramentas válidas e robustas. Este estudo teve como objetivo traduzir, adaptar culturalmente e validar para português o Questionário da Síndrome Visual do Computador (CVS-Q©). Métodos: O procedimento foi realizado em 5 fases: tradução direta, síntese da tradução, tradução inversa, consolidação por um painel de especialistas, e pré-teste. Para fazer o pré-teste foi realizado um estudo piloto transversal aplicado a uma amostra de 26 participantes que completaram a versão pré-final da versão portuguesa do CVS-Q©, questionando por dificuldades, compreensão e sugestões de melhoria do questionário. Para avaliar a confiança e validade da versão portuguesa do CVS-Q© foi realizado um estudo transversal de validação em uma amostra diferente (280 funcionários). Resultados: No préteste, 96.2% dos participantes não apresentaram dificuldades no preenchimento do questionário, enquanto 84.0% indicaram que era claro e compreensível. Obteve-se, então, o CVS-Q© em português (Questionário da Síndrome Visual do Computador, CVS-Q PT©). A sua validação revelou uma boa consistência interna da sua escala (Cronbach’s alpha=0.793), boa estabilidade tem poral (coeficiente de correlação interclasse=0.847; 95% CI 0.764-0.902, kappa=0.839), sensibilidades e especificidades adequadas (78.5% e 70.7%, respetivamente), boa capacidade de discriminação (área abaixo da curva=0.832; 95% CI 0.784-0.879), e uma adequada validade da convergência com o índice de doença da superfície ocular (ocular surface disease index - OSDI; coeficiente de correlação de Spearman=0.728, p<0.001). A análise fatorial revelou um único fator responsável por explicar a variância comum em 37.7%. Um funcionário com uma pontuação ≥7 pontos sofria de síndrome visual do computador. Conclusão: O CVS-Q PT© pode ser considerada uma ferramenta intuitiva, de fácil interpretação e com boas pro priedades psicométricas para avaliar a síndrome visual do computador em funcionários portugueses expostos a ecrãs digitais. Este questionário facilitará as decisões sobre medidas preventivas, intervenções e tratamento, e a comparação entre as populações expostas em diferentes países de língua portuguesa.This work was supported by the Portuguese Foundation for Science and Technology in the framework of the Strategic Funding UIDB/04650/2020. The authors thank the Vice-Rectorate of Research of the University of Alicante for the pre-doctoral training contract for the first author (UAFPU2019-08). This article will form part of the first author’s doctoral thesis

    Assessment of the colorimetric behaviour of different spectrophotometers

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    Comunicación presentada en 36th IARIGAI International Research Conference, Stockholm, September 2009.Colour reproduction is based on the ability to communicate colour information accurately. The different instrument manufacturers, models and conditions result in difficult colour communication due to the loose or inexistent inter-instrumental agreement between them. With this study we have tried to develop an application to correct colour instruments by software by applying multidimensional polynomial transformations between pairs of instruments. This application will filter one spectrophotometer measurement, and apply a correcting factor to emulate the colorimetric response of any other spectrophotometer

    Global color estimation of special-effect coatings from measurements by commercially available portable multiangle spectrophotometers

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    Colors of special-effect coatings have strong dependence on illumination/viewing geometry and an appealing appearance. An open question is to ask about the minimum number of measurement geometries required to completely characterize their observed color shift. A recently published principal components analysis (PCA)-based procedure to estimate the color of special-effect coatings at any geometry from measurements at a reduced set of geometries was tested in this work by using the measurement geometries of commercial portable multiangle spectrophotometers X-Rite MA98, Datacolor FX10, and BYK-mac as reduced sets. The performance of the proposed PCA procedure for the color-shift estimation for these commercial geometries has been examined for 15 special-effect coatings. Our results suggest that for rendering the color appearance of 3D objects covered with special-effect coatings, the color accuracy obtained with this procedure may be sufficient. This is the case especially if geometries of X-Rite MA98 or Datacolor FX10 are used.The authors are grateful to EMRP for funding the project “Multidimensional Reflectometry for Industry.” The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. This study was also supported by the Spanish Ministry of Economy and Competitiveness under grant no. DPI2011-30090-C02-02 and the European Union

    Influencia del tono de los pigmentos de absorción en la percepción de sparkle

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    Para poder garantizar un buen control de calidad de los productos es necesario disponer de medidas instrumentales válidas y trazables de todos los atributos visuales que caracterizan la apariencia de un material (color, brillo, textura y translucidez). El objetivo de este trabajo es por tanto evaluar el atributo visual de textura asociado a los pigmentos de efecto especial con el fin de poder establecer una escala de medida. En particular, este estudio evalúa la influencia del tono de los pigmentos de absorción en la percepción del sparkle. Para tal fin, se usaron 9 muestras con una variación sistemática de tono alrededor del diagrama cromático. Se diseñó un experimento visual basado en la comparación de tripletes para posteriormente aplicar un algoritmo de escalado multidimensional y obtener así un valor relativo de sparkle percibido. Los resultados obtenidos confirman que el tono del pigmento de absorción no influye en la percepción del sparkle.Al Ministerio de Economía y Competitividad por el proyecto RTI2018-096000-BI00. Además, los autores agradecen la participación de todos los observadores en el experimento visual

    Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings

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    A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description of the spectral bidirectional reflectance distribution function (BRDF). The analysis of experimental spectral BRDF was carried out by means of principal component analysis. From this analysis, a set of nine measurement geometries was proposed to characterize special effect coatings. It was shown that, for two different special effect coatings, these geometries provide a good prediction of their complete color shift.The authors are grateful to “Plan Nacional de Física” for funding this work (FIS2010-19756-E), to CSIC’s JAE Program, and the “European Social Fund” for awarding us a research trainee. This study was also supported by the Spanish Ministry of Economy and Competitiveness under the grant DPI2011-30090-C02-02 and the European Union

    Fear Detection in Multimodal affective computing: Physiological Signals versus Catecholamine Concentration

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    Affective computing through physiological signals monitoring is currently a hot topic in the scientific literature, but also in the industry. Many wearable devices are being developed for health or wellness tracking during daily life or sports activity. Likewise, other applications are being proposed for the early detection of risk situations involving sexual or violent aggressions, with the identification of panic or fear emotions. The use of other sources of information, such as video or audio signals will make multimodal affective computing a more powerful tool for emotion classification, improving the detection capability. There are other biological elements that have not been explored yet and that could provide additional information to better disentangle negative emotions, such as fear or panic. Catecholamines are hormones produced by the adrenal glands, two small glands located above the kidneys. These hormones are released in the body in response to physical or emotional stress. The main catecholamines, namely adrenaline, noradrenaline and dopamine have been analysed, as well as four physiological variables: skin temperature, electrodermal activity, blood volume pulse (to calculate heart rate activity. i.e., beats per minute) and respiration rate. This work presents a comparison of the results provided by the analysis of physiological signals in reference to catecholamine, from an experimental task with 21 female volunteers receiving audiovisual stimuli through an immersive environment in virtual reality. Artificial intelligence algorithms for fear classification with physiological variables and plasma catecholamine concentration levels have been proposed and tested. The best results have been obtained with the features extracted from the physiological variables. Adding catecholamine’s maximum variation during the five minutes after the video clip visualization, as well as adding the five measurements (1-min interval) of these levels, are not providing better performance in the classifiers.This research has been supported by the Madrid Governement (Comunidad de Madrid, Spain) under the ARTEMISA-UC3M-CM research project (reference 2020/00048/001), the EMPATIACM research project (reference Y2018/TCS-5046) and the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M26), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation)

    Role of the Transforming Growth Factor-β in regulating hepatocellular carcinoma oxidative metabolism.

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    Transforming Growth Factor beta (TGF-β) induces tumor cell migration and invasion. However, its role in inducing metabolic reprogramming is poorly understood. Here we analyzed the metabolic profle of hepatocellular carcinoma (HCC) cells that show diferences in TGF-β expression. Oxygen consumption rate (OCR), extracellular acidifcation rate (ECAR), metabolomics and transcriptomics were performed. Results indicated that the switch from an epithelial to a mesenchymal/migratory phenotype in HCC cells is characterized by reduced mitochondrial respiration, without signifcant diferences in glycolytic activity. Concomitantly, enhanced glutamine anaplerosis and biosynthetic use of TCA metabolites were proved through analysis of metabolite levels, as well as metabolic fuxes from U-13C6-Glucose and U-13C5-Glutamine. This correlated with increase in glutaminase 1 (GLS1) expression, whose inhibition reduced cell migration. Experiments where TGF-β function was activated with extracellular TGF-β1 or inhibited through TGF-β receptor I silencing showed that TGF-β induces a switch from oxidative metabolism, coincident with a decrease in OCR and the upregulation of glutamine transporter Solute Carrier Family 7 Member 5 (SLC7A5) and GLS1. TGF-β also regulated the expression of key genes involved in the fux of glycolytic intermediates and fatty acid metabolism. Together, these results indicate that autocrine activation of the TGF-β pathway regulates oxidative metabolism in HCC cells

    Visual and Instrumental Assessments of Color Differences in Automotive Coatings

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    The interest in gonioapparent pigments (metallic, pearlescent, interference, or diffractive) has increased in the last few years, especially for applications in the automotive industry. To assure a proper characterization of colors with gonioapparent pigments, commercial devices have appeared to characterize the color in different geometries, which are called multiangle spectrophotometers. As the gonioapparent pigments and multiangle instruments are relatively new, no studies exist regarding the instrumental-based procedure followed in the industry, and if the results provided are in agreement with the observer perception. Consequently, the main objective of this study was to examine the correlation of the instrumental color differences with visual assessments. The instrumental color difference was calculated with the color difference formula AUDI2000 (specific for this sector) between the pairs of similar samples of three types of coated panels (solid, metallic, and pearlescent). The values measured by a telespectroradiometer in a directional lighting booth and the colorimetric values obtained by means of a multiangle spectrophotometer BYK-mac were considered for this purpose. Additionally, a visual experiment was conducted to quantify the color difference by using the gray-scale method. The results revealed that an acceptable instrumental correlation existed despite the visual and the instrumental correlation being worse. In particular, it was checked that observers accepted a larger number of color pairs, that is, the visual color difference was smaller than the tolerance demanded by the industry (derived from AUDI2000).Preprin

    Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)

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    This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe
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