Polymeric foams as the matrix of voltammetric sensors for the detection of catechol, hydroquinone, and their mixtures

Producción CientíficaPorous electrodes based on polymethylmethacrylate and graphite foams (PMMA_G_F) have been developed and characterized. Such devices have been successfully used as voltammetric sensors to analyze catechol, hydroquinone, and their mixtures. The presence of pores induces important changes in the oxidation/reduction mechanism of catechol and hydroquinone with respect to the sensing properties observed in nonfoamed PMMA_graphite electrodes (PMMA_G). The electropolymerization processes of catechol or hydroquinone at the electrode surface observed using PMMA_G do not occur at the surface of the foamed PMM_G_F. In addition, the limits of detection observed in foamed electrodes are one order of magnitude lower than the observed in the nonfoamed electrodes. Moreover, foamed electrodes can be used to detect simultaneously both isomers and a remarkable increase in the electrocatalytic properties shown by the foamed samples, produces a decrease in the oxidation potential peak of catechol in presence of hydroquinone, from +0.7 V to +0.3 V. Peak currents increased linearly with concentration of catechol in presence of hydroquinone over the range of 0.37·10−3 M to 1.69·10−3 M with a limit of detection (LOD) of 0.27 mM. These effects demonstrate the advantages obtained by increasing the active surface by means of porous structures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482-R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA-011U16

Estimation of comprehensive two-dimensional gas chromatographic response from one-dimensional gas chromatography data

Trabajo presentado a la XV Reunión Científica de la Sociedad Española de Cromatografía y Técnicas Afines (SECyTA) celebrada en Castellón de la Plana del 28 al 30 de octubre de 2015Optimization of a separation in comprehensive two-dimensional gas chromatography (GC×GC) requires the selection of an appropriate set column, and the optimisation of their respective dimensions, temperature programs and flow rates. Until not so long ago, a time consuming trial and error process was the only way to select the columns and chromatographic conditions for the two GC dimensions. During the last few years, several attempts have been proposed to estimate the chromatographic response in GC×GC [1-4]. Although most of these methods are helpful contributions, some of them focussed exclusively on the retention time estimation and do not consider the effect of peak width, also essential for a correct prediction of the chromatographic separation capability. Others are based on theoretical formulas not applicable to the extreme experimental conditions used in GC×GC, or are only valid for specific types of compounds or stationary phases: these models cannot be corrected for different separation problems. In this work, modelization of retention time and peak width has been carried out from experimental 1D GC data in order to estimate the response in GC×GC separation for different column sets operated under different flows and temperatures. Several theoretical and experimental models are proposed for estimation of 1D and 2D retention time and peak width; in experimental models, 1D GC data are required together with information on column characteristics and operation conditions. Models for hold-up time, retention factor and peak width were first validated in 1D GC from the fit between experimental and calculated data. Their validation in GC×GC was carried out by using n-alkanes and a mixture of disaccharides as their trimethylsilyl oxime derivatives. Comparison of experimental and estimated data showed good results for retention time in both first and second dimension. Peak widths presented, however, some errors, caused by the no consideration on estimation of the effect of the modulator or the rather unusual chromatographic conditions used. The developed programme is very versatile as it can be used for the calculation of the chromatographic response of compounds with different polarity and volatility, analysed under different pressures and temperature ramps, and with different sets of columns. [1] J.V. Seeley, E.M. Libby, K.A.H. Edwards, S.K. Seeley, J. Chromatogr. A 1216 (2009) 1650. [2] F.L. Dorman, P.D. Schettler, L.A. Vogt, J.W. Cochran, J. Chromatogr. A 1186 (2008) 196. [3] Y. Zhao, J. Zhang, B. Wang, S.H. Kim, A. Fang, B. Bogdanov, Z. Zhou, C. McClain, X. Zhang, J. Chromatogr. A 1218 (2011) 2577. [4] S. Zhu, S. He, D.R. Worton, A.H. Goldstein, J. Chromatogr. A 1233 (2012) 147. Acknowledgements: This work has been funded by Ministerio de Economía y Competitividad (project CTQ2012-32957), Comunidad Autónoma de Madrid (Spain) and European funding from FEDER program (AVANSECAL-CM S2013/ABI-3028) and Fundación Ramón Areces. ACS thanks Ministerio de Economía y Competitividad of Spain for a Ramón y Cajal contract.CTQ2012-32957Peer reviewe

Mortar with pet—Preliminary results

ICEER2019 - 6th International Conference on Energy and Environment Research: “Energy and environment: challenges towards circular economy”, 22 -25 July 2019, Aveiro, PortugalThe objective of this work is to evaluate the performance and feasibility of the use of coating mortars with the incorporation of ground polyethylene terephthalate (PET) waste. It was studied the performance of 1: 4 mortars in weight with partial replacement of the aggregate by PET residuals in different percentages (0%, 5% and 10%). Obtained results showed a decrease of the mechanical resistance of mortars in the inverse proportion of the use of PET residues of the mixture, an increase in resistance to water absorption by capillary action and a decrease in thermal conductivity. These results support the potential use of PET waste in coating mortars, thereby contributing to reduce the environmental impact caused by plastic waste. However, in order to be considered energy efficient, this new material needs further improvements.info:eu-repo/semantics/publishedVersio

Chemical modification of titanium precursor to obtain stable silica-titania sol: acetylacetone

[ES] La técnica Sol-Gel se ha utilizado para sintetizar una serie de sistemas multicomponentes, entre ellos SiO2 – TiO2. El mayor problema en la obtención de geles multicomponentes estables es la desigual velocidad de hidrólisis y condensación que presentan los alcóxidos precursores de los cationes de interés. En este trabajo se muestra cómo adicionando acetilacetona, acacH, al sistema TEOS – Ti(OBu)4 – H2O se puede obtener un sol estable. Se tomaron diferentes concentraciones de los precursores de silicio y titanio y una sola concentración de acacH. Se utilizó espectroscopia infrarroja, FTIR, para identificar los grupos funcionales presentes en el sistema y además se midió regularmente la viscosidad para determinar cualitativamente el avance de la policondensación del sistema.[EN] Sol-gel processing has become a well established technique for producing ceramic powders or glasses. This processing has been utilized to synthesize several interesting systems, e.g. the SiO2 – TiO2 system. A major concern in the stable multicomponent geles is that the hydrolysis and condensation velocities are diferent for each precursor, TEOS and Ti(OBu)4 in this work. The chemical control of these reactions is currently performed by adding complexing reagents that react with metal alkoxides at a molecular level, giving rise to new molecular precursors of different structure, reactivity and functionanality. This paper shows that stable TEOS – Ti(OBu)4 – H2O sol can be reproducibly prepared in the presence of acetylacetone. We shall then show that the acac behaves as a ligand, directly bonded to the titanium ion. Thus the formation of precipitate is avoided. Infra-red spectroscopy (FTIR) and viscosity measures were used to demostrated this behaviour of the system.Este trabajo fue financiado a través de los proyectos COLCIENCIAS N° 1103-05-605-93 y VRI-Universidad del Cauca N° 752. Agradecemos a Ecopetrol-ICP la colaboración prestada con los estudios de espectroscopia infrarroja y a la red CyTED VIII.E la ayuda económica y técnica gracias a la cual A. Mafla pudo realizar su pasantía en el ICVCSIC de Madrid-España.Peer reviewe

The use of muscle biomarkers for assessing physiological effects of heavy metal pollution in the greater white-toothed shrew (Crocidura russula)

The greater white-toothed shrew Crocidura russula has been used as a sentinel species for estimating environmental risks to human populations. Previous studies in mining areas have focused on the liver of shrews as the primary target of physiological and metabolic changes due to heavy metal pollution. However, populations persist even when detoxification by the liver seems to be compromised and damage is observed. These pollutant-adapted individuals inhabiting contaminated sites may exhibit altered biochemical parameters that confer increased tolerance in various tissues other than the liver. The skeletal muscle tissue of C. russula might be an alternative tissue that allows the survival of organisms inhabiting historically polluted sites due to the detoxification of redistributed metals. Organisms from two heavy metal mine populations and one population derived from an unpolluted site were used to determine the detoxification activities, antioxidant capacity, and oxidative damage, as well as cellular energy allocation parameters and acetylcholinesterase activity (a biomarker of neurotoxicity). Muscle biomarkers differ between shrews from polluted sites and shrews from the unpolluted location, with the mine animals showing: (1) a decreased energy consumption concomitant with increased energy reserves and total available energy; (2) reduced cholinergic activity, suggesting an impairment of neurotransmission at the neuromuscular junction; (3) an overall decrease in detoxification capacity and enzymatic antioxidant response and a higher level of lipid damage. Also, some of these markers differed between females and males. These changes may have resulted from a decreased detoxifying capacity of the liver and could potentially bring about significant ecological effects for this highly active species. Heavy metal pollution induced physiological changes in Crocidura russula showing that skeletal muscle may serve as a backup sink organ allowing rapid species adaptation and evolution.publishe

Evidência de acesso lexical não seletivo em crianças de uma escola bilíngue português-inglês

The issue of language selectivity regarding lexical access of bilingual adults has been thoroughly reported in the literature. However, studies with bilingual children are still limited, especially in the Brazilian context, where the number of bilingual schools has been increasing rapidly in the last few years. To fill this gap, the present study was conducted with the goal of investigating whether the same cognate facilitation effect reported for bilingual adults is also true for bilingual children. To do so, two experiments were carried out. In Experiment 1, 53 Portuguese-speaking (L1) children learning English as a second language (L2) from 3rdand 7thgrade completed lexical decision tasks, which included cognates, noncognates and pseudowords, in both Portuguese and English. In Experiment 2, 18 age-matched English monolinguals performed the English version of the lexical decision task. The results of Experiment 1 showed that the cognate effect was evident for both 3rdand 7thgraders, when the task was performed in the L2. However, no statistical difference between the two grades was found. When performing the task in the L1, the bilingual groups showed no cognate effect, which suggests that these participants had not reached a level of proficiency in which the L2 can influence L1 processing. The results of Experiment 2 showed no cognate facilitation effect for monolinguals, indicating that the results of the early L2 learners, in the English version of the lexical decision task, were indeed due to the cognate status of the words of the bilingual'stwo languages. In short, the present results favor the nonselective view of lexical access and the effect of proficiency in the perception of cross language similarity.A questão da seletividade da língua no acesso lexical de adultos bilíngues tem sido amplamenterelatada na literatura. No entanto, estudos com crianças bilíngues ainda são limitados, principalmente no contexto brasileiro, no qual o número de escolas bilíngues tem aumentado rapidamente nos últimos anos. Para preencher essa lacuna, o presente estudo teve com o objetivo investigar se o mesmo efeito de facilitação cognata relatado no caso de adultos bilíngues também é verdadeiro para crianças bilíngues. Para isso, dois experimentos foram conduzidos. No Experimento 1, um total de 53 crianças falantes nativas de português (L1) aprendendo o inglês como segunda língua (L2), de 3ª e 7ª série, realizaram uma tarefa de decisão lexical que continha cognatos, não-cognatos e pseudopalavras, tanto em português como em inglês. No Experimento 2, 18 monolíngues falantes de inglês realizaram a tarefa de decisão lexical na versão em inglês. Os resultados do Experimento 1 mostraram que o efeito cognato foi evidente para os dois grupos de bilíngues quando a tarefa foi realizada na L2-inglês, embora não tenha sido encontrada diferença estatística entre as séries. Ao realizar a tarefa na L1, os grupos bilíngues não apresentaram efeito cognato, o que indica que esses participantes não atingiram um nível de proficiência em que a L2 pode influenciar o processamento da L1. Os resultados do Experimento 2 mostraram que não houve efeito de facilitação cognata para os monolíngues, indicando que os resultados dos aprendizes precoces de L2, na versão em inglês da tarefa de decisão lexical foram, realmente, devido ao status de cognato das palavras das duas línguas dos bilíngues. Em suma, os presentes resultados favorecem a visão não seletiva do acesso lexical e o efeito da proficiência na percepção da similaridade entre línguas

Guidelines for diagnosis and treatment of Hunter Syndrome for clinicians in Latin America

This review aims to provide clinicians in Latin America with the most current information on the clinical aspects, diagnosis, and management of Hunter syndrome, a serious and progressive disease for which specific treatment is available. Hunter syndrome is a genetic disorder where iduronate-2-sulfatase (I2S), an enzyme that degrades glycosaminoglycans, is absent or deficient. Clinical manifestations vary widely in severity and involve multiple organs and tissues. An attenuated and a severe phenotype are recognized depending on the degree of cognitive impairment. Early diagnosis is vital for disease management. Clinical signs common to children with Hunter syndrome include inguinal hernia, frequent ear and respiratory infections, facial dysmorphisms, macrocephaly, bone dysplasia, short stature, sleep apnea, and behavior problems. Diagnosis is based on screening urinary glycosaminoglycans and confirmation by measuring I2S activity and analyzing I2S gene mutations. Idursulfase (recombinant I2S) (Elaprase®, Shire) enzyme replacement therapy (ERT), designed to address the underlying enzyme deficiency, is approved treatment and improves walking capacity and respiratory function, and reduces spleen and liver size and urinary glycosaminoglycan levels. Additional measures, responding to the multi-organ manifestations, such as abdominal/inguinal hernia repair, carpal tunnel surgery, and cardiac valve replacement, should also be considered. Investigational treatment options such as intrathecal ERT are active areas of research, and bone marrow transplantation is in clinical practice. Communication among care providers, social workers, patients and families is essential to inform and guide their decisions, establish realistic expectations, and assess patients' responses.Hospital de Clinicas de Porto Alegre Serviço de Génetica MédicaUniversidade Federal do Rio Grande do Sul Departamento de GéneticaInstituto Nacional de Genética Médica PopulacionalAsociación Colombiana de Neurología InfantilInstituto Mexicano del Seguro SocialInstituto de Estudios AvanzadosHospital de NiñosLa Misericordia University HospitalUniversidade Federal de São Paulo (UNIFESP) Centro de Referência em Erros Inatos do MetabolismoUniversidade Federal de BahiaUniversidad de Chile Instituto de Nutrición y Tecnología de los AlimentosHospital Italiano Instituto de Genética MédicaHospital Pequeno Príncipe Departamento de NeuropediatraHospital Universitario AustralUNIFESP, Centro de Referência em Erros Inatos do MetabolismoSciEL

Polymyxin-Resistant Acinetobacter spp. Isolates: What is Next?

Univ Fed Sao Paulo, Div Infect Dis, Lab Especial Microbiol Clin, BR-04025010 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Infect Dis, Lab Especial Microbiol Clin, BR-04025010 Sao Paulo, SP, BrazilWeb of Scienc

Analysis of milk using a portable potentiometric electronic tongue based on five polymeric membrane sensors

Producción CientíficaA portable potentiometric electronic tongue (PE-tongue) was developed and applied to evaluate the quality of milk with different fat content (skimmed, semi-skimmed, and whole) and with different nutritional content (classic, calcium-enriched, lactose-free, folic acid–enriched, and enriched in sterols of vegetal origin). The system consisted of a simplified array of five sensors based on PVC membranes, coupled to a data logger. The five sensors were selected from a larger set of 20 sensors by applying the genetic algorithm (GA) to the responses to compounds usually found in milk including salts (KCl, CaCl2, and NaCl), sugars (lactose, glucose, and galactose), and organic acids (citric acid and lactic acid). Principal component analysis (PCA) and support vector machine (SVM) results indicated that the PE-tongue consisting of a five-electrode array could successfully discriminate and classify milk samples according to their nutritional content. The PEtongue provided similar discrimination capability to that of a more complex system formed by a 20-sensor array. SVM regression models were used to predict the physicochemical parameters classically used in milk quality control (acidity, density, %proteins, %lactose, and %fat). The prediction results were excellent and similar to those obtained with a much more complex array consisting of 20 sensors. Moreover, the SVM method confirmed that spoilage of unsealed milk could be correctly identified with the simplified system and the increase in acidity could be accurately predicted. The results obtained demonstrate the possibility of using the simplified PE-tongue to predict milk quality and provide information on the chemical composition of milk using a simple and portable system.Ministerio de Asuntos Económicos y Transformación Digital y FEDER (grant RTI 2018-097990-B-100)Junta de Castilla y Leon-FEDER (grant VA275P18) and (Infraestructuras Red de Castilla y León (INFRARED UVA01

Sequence-aware multimodal page classification of Brazilian legal documents

The Brazilian Supreme Court receives tens of thousands of cases each semester. Court employees spend thousands of hours to execute the initial analysis and classification of those cases -- which takes effort away from posterior, more complex stages of the case management workflow. In this paper, we explore multimodal classification of documents from Brazil's Supreme Court. We train and evaluate our methods on a novel multimodal dataset of 6,510 lawsuits (339,478 pages) with manual annotation assigning each page to one of six classes. Each lawsuit is an ordered sequence of pages, which are stored both as an image and as a corresponding text extracted through optical character recognition. We first train two unimodal classifiers: a ResNet pre-trained on ImageNet is fine-tuned on the images, and a convolutional network with filters of multiple kernel sizes is trained from scratch on document texts. We use them as extractors of visual and textual features, which are then combined through our proposed Fusion Module. Our Fusion Module can handle missing textual or visual input by using learned embeddings for missing data. Moreover, we experiment with bi-directional Long Short-Term Memory (biLSTM) networks and linear-chain conditional random fields to model the sequential nature of the pages. The multimodal approaches outperform both textual and visual classifiers, especially when leveraging the sequential nature of the pages.Comment: 11 pages, 6 figures. This preprint, which was originally written on 8 April 2021, has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in the International Journal on Document Analysis and Recognition, and is available online at https://doi.org/10.1007/s10032-022-00406-7 and https://rdcu.be/cRvv