A linear free-energy relationship for the prediction of metal ion complexing properties in hybrid carbon-based scavengers

The authors thank the Spanish Ministry of Science & Innovation, and the Junta de Andalucia for financial support (grants MAT2009-14185-C02-01, P09-FQM-4765 and a fellowship to A. Penas) and the CPL Carbon Link for the kind donation of carbon samples. The authors also thank CICT of University of Jaen for providing technical facilities.Supplementary information https://www.rsc.org/suppdata/d3/nj/d3nj01000g/d3nj01000g1.pdfA novel and straightforward approach to accurately predict, through direct potentiometric measurements, the complexing properties and adsorption capacity of novel carbon-based hybrid scavengers toward particular metal ions is described. This innovative approach establishes a linear free-energy relationship (LFER) between the complexing properties of the free-complexing function in solution and the complexing retention capacity of the functionalized carbon-based hybrid material (complexing function supported). In particular, we report the first detailed study concerning the metal ion complexing properties, as well as the complexing mechanisms involved in covalently-bonded carbon-supported hyperbranched polyethyleneimines, towards a series of metal ions of environmental and technical interest, such as Mn2+, Cd2+, Hg2+, Pd2+ and Cr3+. The study based on adsorption isotherm measurements and potentiometric studies of non-bonded hyperbranched polyethyleneimines (HBPEIs) (free in solution) and carbon-supported HBPEI (hybrid material, C-PEI) revealed that bonded HBPEI molecules fully define and control the metal ion complexing abilities of C-PEI, while the carbon structure acts only as a solid support. These results corroborate the prevalence of a reliable linear free-energy relationship (LFER) between the retention capacities of the hybrid material (C-PEI) and the complexing properties of free HBPEI in solution, which supposes a novel approach to easily predict the metal ion complexing properties of carbon-based hybrid materials, through a simple potentiometric titration analysis of the free complexing ligand in solution. This approach has the potential to predict retention capacities of solid materials (actual or proposed) exhibiting surfaces functionalized with HPBEI.Spanish Ministry of Science & InnovationJunta de Andalucia MAT2009-14185-C02-01, P09-FQM-476

Unveiling the structural transformations of the PW11Co@ZIF-67 nanocomposite induced by thermal treatment

A guest@host POM@ZIF nanocomposite—PW11Co@ZIF-67—has been synthesized using an in situ strategy. This new nanocomposite exhibits (i) individually ZIF-67-cage-confined POM units, (ii) structural defects in the ZIF-67 host induced by the POM, and (iii) charge transfer from the ZIF-67 to the confined POM. In addition, it has served as a template to produce a set of derived samples by applying thermal treatment at various temperatures (200, 400, 500, 600, and 950 °C) under a N2 flow. We have used multiple characterization techniques, ICP-OES, CHNS analysis, XPS, ATR-IR, PXRD, Raman spectroscopy, N2/ CO2 adsorption analysis, CV, and TEM/EDS, to fully assess the thermally-induced variation tendencies. The first two derivatives—D200 and D400—show the same nanoarrangement as the PW11Co@ZIF-67 precursor, although with incipient signs of both POM and ZIF-67 structural decompositions. The following samples—D500, D600, and D950—exhibit a carbonaceous nature consisting of C-embedded compositionally complex nanoparticles that involve Co and W present as diverse species, metallic/oxide/phosphate/ phosphide. D500 presents the best intrinsic electrochemistry, probably due to the high proportion of pyridinic N moieties doping its C matrix combined with small-sized and highly dispersed Co-enriched nanoparticles. This study focuses on the need for a thorough physicochemical characterization of this class of highly nanostructured materials with a view to exploring their application in electrocatalysis.Portuguese Foundation for Science and Technology POCI-01-0145-FEDER-016422European CommissionPortuguese Foundation for Science and TechnologyEuropean Commission UIDB/50006/2020 UIDP/50006/2020 2021.00771.CEECIND/CP1662/CT0007 CEECIND/03877/2018 CEECIND/00793/201

Carbon-supported statistically distributed polyethyleneimine/palladium (II) complexes as efficient and sustainable Sonogashira catalysts

We thank the Spanish Ministry of Science & Innovation, and the Junta de Andalucía for financial support (grants MAT2009-14185-C02-01, P09-FQM-4765 and a fellowship to A. Peñas). To CPL Carbon Link for kind donation of carbon samples. We also thank CICT of University of Jaén for technical facilities.A novel approach toward the obtaining of a Pd (II) carbon-supported catalyst based on a statistical distributed polymer (hyperbranched polyethyleneimine) and its use as a highly efficient and sustainable catalyst for Sonogashira-type coupling reactions is presented. The heterogenous Pd (II)/HBPEI catalyst fabricated through a facile, cost-effective and scalable procedure provides an innovative catalyst structure based on statistical distributed singular catalytic centers with well-defined Pd-Polymer chemical interactions, highly resistant to suffer leaching processes and extensively and homogenously distributed across the whole carbon surface. The catalyst exhibited excellent catalytic and recycling activity for several cross-coupling reactions between different aryl halides and terminal alkynes, free of any undesired by-product and in excellent yields, under air atmosphere, using water as solvent, at moderate temperatures (65 °C) and avoiding the use of phosphine derivatives, Cu(I) as co-catalyst and excess of any of the reactant. Therefore, the reported Pd(II)-HBPEI carbon-supported material can be considered a truly competitive heterogeneous Pd(II) catalyst for large-scale under green chemistry conditions.Spanish Ministry of Science & InnovationJunta de Andalucía MAT2009-14185-C02-01, P09-FQM-4765University of Jaén, CIC

Determination of biosorption mechanism in biomass of agave, using spectroscopic and microscopic techniques for the purification of contaminated water

[Abstract] Lead (Pb2+) and copper (Cu2+) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from Agave atrovirens) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a qmax of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper.[Resumen] El plomo (Pb2+) y el cobre (Cu2+) son metales contaminantes debido a su toxicidad; sin embargo, la extracción de estos metales es indispensable para el desarrollo económico, por lo que es importante buscar alternativas eficientes y de bajo costo que puedan remover metales pesados de los diversos cuerpos de agua. Una de las alternativas utilizadas en este trabajo es la biosorción, para la cual se utilizó un residuo agroindustrial (epidermis de Agave atrovirens), para evaluar la afinidad de remoción del plomo y cobre en soluciones acuosas; adicionalmente, se emplearon técnicas de espesctroscopía y microscopía que permitieron elucidar y corroborar la capacidad de remoción y afinidad que tuvo la epidermis de A. atrovirens para ambos metales estudiados. El valor óptimo de pH para la remoción de ambos metales fue 3. Las isotermas de adsorción arrojaron una qmax de 25.7 y 8.6 mg/g para el plomo y cobre, respectivamente. Ajustando al modelo de Langmuir-Freundlich, las cinéticas de adsorción resultaron de pseudo-segundo orden, se encontró que el tiempo de equilibrio es a los 140 min. El análisis espectroscópico y microscópico, corroboró la afinidad entre metales y grupos funcionales del agave, así como con el análisis elemental, el cual reportó 17.38% de plomo y 4.25% de cobre

Adsorptive Capacity, Inhibitory Activity and Processing Techniques for a Copper-MOF Based on the 3,4-Dihydroxybenzoate Ligand

Supplementary Materials: The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/molecules27228073/s1Acknowledgments: E.E. is grateful to the Government of the Basque Country for the predoctoral fellowship and R.F.M for the Junior Research Position CEECIND/ 00553/2017. S.R. acknowledges the Juan de la Cierva Incorporación Fellowship (grant agreement no. IJC2019-038894-I). The authors thank for technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) and also wish to acknowledge the terrific help of all reviewers of the present manuscript, whose comments helped to improve the quality of the work.Funding: This work was developed within the scope of the projects given by the University of the Basque Country (GIU 20/028 Junta de Andalucía (B-FQM-734-UGR20, ProyExcel_00386 and FQM-394), the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) (PGC2018-102052-B-C21) and the CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020).Due to the fast, emerging development of antibiotic-resistant bacteria, the need for novel, efficient routes to battle these pathogens is crucial; in this scenario, metal-organic frameworks (MOFs) are promising materials for combating them effectively. Herein, a novel Cu-MOF—namely 1—that displays the formula [Cu3L2(DMF)2]n (DMF = N,N-dimethylformamide) is described, synthesized by the combination of copper(II) and 3,4-dihydroxybenzoic acid (H3L)—both having well-known antibacterial properties. The resulting three-dimensional structure motivated us to study the antibacterial activity, adsorptive capacity and processability of the MOF in the form of pellets and membranes as a proof-of-concept to evaluate its future application in devices.Government of the Basque Country for the predoctoral fellowship and R.F.M for the Junior Research Position CEECIND/00553/2017Juan de la Cierva Incorporación Fellowship (grant agreement no. IJC2019-038894-I)SGIker of UPV/EHUEuropean funding (ERDF and ESF)University of the Basque Country (GIU 20/028 Junta de Andalucía (B-FQM-734-UGR20, ProyExcel_00386 and FQM-394)Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) (PGC2018-102052-B-C21)CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020

Sirena: Autonomous integrated system for naval recognition and exploration

Peer Reviewe

Evaluación agronómica preliminar de genotipos de arroz (Oryza sativa L.) en condiciones de suelo salino de Yaguachi, Ecuador

Soil salinity is considered one of the main abiotic stresses that affect rice cultivation throughout the world. The main objective of this study was to carry out the preliminary agronomic evaluation of five commercial rice varieties (INIAP11, INIAP14, SFL-011, INIAP-FL-Arenillas and Fedearroz-60) under saline soil conditions in Yaguachi, Guayas, Ecuador. A completely randomized block design was used to estimate the agronomic response of the materials by quantifying grain yield t.ha-1 (Yield), number of tillers.m-2 (TN), plant height at harvest (PH), number of panicles.m-2 (NPM), panicle length (PL), number of grains/panicle (NGP), number of filled grains/panicle (NFG), number of vain grains (NVG), weight of 1000 grain (P1000) and content of chlorophyll at 30 (C30D) and 60 (C60D) days. The analysis of variance reflected a high phenotypic diversity among the varieties studied, showing adequate adaptation to the level of salinity contained in the soil used for the study. The INIAP-FL-Arenillas, INIAP14, INIAP11 and FEDEARROZ-60 varieties were the genotypes with the best responses under the study conditions, expressed in higher productivity levels. The results also suggest the need to continue evaluating these varieties with and without saline stress conditions, to discriminate the effect of genotype by environment interaction and confirm the level of tolerance to saline stress present in these genotypes, optimizing the selection of the appropriate germplasm in breeding programs, aiming to obtaining genotypes tolerant to saline soils.La salinidad del suelo se considera uno de los principales estreses abióticos que afectan al cultivo del arroz en todo el mundo. El objetivo principal de este estudio fue realizar la evaluación agronómica preliminar de cinco variedades comerciales de arroz (INIAP11, INIAP14, SFL-011, INIAP-FL-Arenillas y Fedearroz-60) en condiciones de suelo salino en Yaguachi, Guayas, Ecuador. Se utilizó un diseño de bloques completamente al azar para estimar la respuesta agronómica de los materiales mediante la cuantificación del rendimiento de grano t.ha-1 (Rendimiento), número de macollos.m-2 (TN), altura de planta a la cosecha (PH), número de panojas.m-2 (NPM), longitud panícula (PL), número de granos/panícula (NGP), número de granos llenos/panícula (NFG), número de granos vanos (NVG), peso de 1000 granos (P1000) y contenido de clorofila a los 30 (C30D) y 60 (C60D) días.  El análisis de varianza reflejó una alta diversidad fenotípica entre las variedades estudiadas, mostrando una adecuada adaptación al nivel de salinidad contenido en el suelo utilizado para el estudio. Las variedades INIAP-FL-Arenillas, INIAP14, INIA-11 y FEDEARROZ-60 fueron los genotipos con mejores respuestas bajo las condiciones de estudio, expresadas en mayores niveles de productividad. Los resultados sugieren la necesidad de continuar evaluando estas variedades en condiciones con y sin estrés salino, para discriminar el efecto de la interacción genotipo por ambiente y confirmar el nivel de tolerancia al estrés salino presente en estos genotipos, optimizando la selección del germoplasma apropiado en programas de mejoramiento, con el objetivo de obtener genotipos tolerantes a suelos salinos

FOOD PRODUCT ACCEPTANCE AND PREFERENCE PREDECTION THROUGH AUTOMATED FACIAL EXPRESSION ANALYSIS (MEDICIÓN DE ACEPTACIÓN Y PREFERENCIA DE PRODUCTOS ALIMENTICIOS MEDIANTE ANÁLISIS AUTOMATIZADO DE EXPRESIONES FACIALES)

ResumenSe presenta un sistema para determinar la aceptación y las preferencias de usuarios en productos alimenticios a través del reconocimiento de emociones. Los cambios en expresiones faciales de 80 sujetos mientras probaban cinco distintos productos alimenticios fueron capturados con el sensor Microsoft Kinect. Las expresiones faciales se contrastaron con las evaluaciones sensoriales de los consumidores. Para el reconocimiento de expresiones faciales en cada cuadro del video, se entrenó una red neuronal y se utilizaron diferentes técnicas de aprendizaje supervisado (como máquinas de soporte vectorial, perceptrón multicapa y árboles de regresión) para determinar que sabores podrían ser aceptados y rechazados por el consumidor.  Se decidió utilizar la red neuronal, y al observar la matriz de confusión se obtiene un porcentaje de reconocimiento adecuado para las siguientes emociones: neutral 94%, sorpesa 98%, felicidad 99% y disgusto 94%. La aplicación industrial es relevante en el sector de Investigación y Desarrollo de la industria de alimentos.Palabras Claves: aceptación de consumidores, análisis sensorial, aprendizaje de máquina, expresiones faciales, Kinect, visualización.AbstractThis paper presents a system for determining consumer acceptance and preferences of food products through emotion recognition. Changes in facial expressions of 80 test subjects while tasting five different food samples were captured using the Microsoft Kinect sensor. The expressions were compared to the consumers’ sensory evaluations. To determine the facial expressions in every video frame, a neural network was trained and different supervised learning techniques (such as support vector machines, multilayer perceptron and regression trees) were used to predict which of the different tastes could be accepted or rejected. A neuronal net was used, when observing the confusion matrix a percentage of adequate recognition was obtained for the following emotions: neutral (94%), surprise (98%), happiness (99%) and disgust (94%). The industrial application of the proposed system is relevant for the Food Industry Research and Development (R&D) by allowing the sampling of a product by potential consumers and analyzing their emotions before launching into market.Keywords: consumer’s acceptance, sensory analysis, facial expressions, Kinect, machine learning, visualization

Análisis de los programas educativos del Parque Ecológico Chipinque, A.C.

La presente investigación tiene como objetivo evaluar los programas educativos del Parque Ecológico Chipinque (PECh), ubicado en Nuevo León, México. Utilizando un nivel de confianza de 90% para estimar el número de muestras necesarias. Se EDUARDO ALANÍS R., ESMERALDA MÉNDEZ V., LIBERTAD LEAL L. ENRIQUE JURADO Y., JAVIER JIMÉNEZ P., HORACIO VILLALÓN M., JOSÉ M. MATA B. 200 CIENCIA UANL / VOL. XII, No. 2, ABRIL - JUNIO 2009 analizó la percepción de los profesores responsables de grupos estudiantiles (de 6 a 24 años de edad) en relación a la duración y contenido del los programas, además del lenguaje y dominio del tema. Los resultados muestran una buena percepción de los programas impartidos en el PECh con una frecuencia de 85%. El 15% lo considera de calidad regular, y tan sólo 1% deficientes