Self-Healing Polymer Nanocomposite Materials by Joule Effect

Nowadays, the self-healing approach in materials science mainly relies on functionalized polymers used as matrices in nanocomposites. Through different physicochemical pathways and stimuli, these materials can undergo self-repairing mechanisms that represent a great advantage to prolonging materials service-life, thus avoiding early disposal. Particularly, the use of the Joule effect as an external stimulus for self-healing in conductive nanocomposites is under-reported in the literature. However, it is of particular importance because it incorporates nanofillers with tunable features thus producing multifunctional materials. The aim of this review is the comprehensive analysis of conductive polymer nanocomposites presenting reversible dynamic bonds and their energetical activation to perform self-healing through the Joule effect

Dietary patterns in Mexican preschool children are associated with stunting and overweight

OBJECTIVE To evaluate the association between dietary patterns, stunting, and overweight among Mexican preschoolers. METHODS This study was conducted with anthropometric (weight, height/length), sociodemographic (age, gender, education level of household head, socioeconomic status, country region and area, ethnicity, and beneficiary of social programs), and dietary data (Semiquantitative-food frequency questionnaire) on children aged from 1 to 4 years collected from the Mexican National Health and Nutrition Survey-2012. Dietary patterns were derived by principal components analysis. The association between dietary patterns, stunting, and overweight was assessed by prevalence ratios (PR), estimated by Poisson regression. RESULTS In total, 1,112 preschoolers (mean age 3.06 years, SD = 1.08 years; 48.8% females) were included in the study; 11.9% of whom presented stunting, and 6.7% overweight. We identified four dietary patterns: Fruits and Vegetables [F&V], Western [W], Traditional [T], and Milk and Liquids [M&L]. Considering the lowest tertile of each dietary pattern as reference, the prevalence of stunting was 2.04 times higher [95%CI: 1.17–3.56] among children in the highest tertile of the “F&V” pattern. The prevalence of stunting was lower among children in the highest tertile of the “W” pattern [PR = 0.48; 95%CI: 0.27–0.85]. Overweight was negatively associated with the “F&V” dietary pattern [PR = 0.37; 95%CI: 0.16–0.85 for its highest tertile], and children whose consumption was mostly equivalent to the “T” pattern showed higher prevalence of stunting [PR = 1.74; 95%CI: 1.01–3.00]. CONCLUSIONS The prevalence of stunting and overweight in a nationwide sample of Mexican preschoolers was associated with dietary patterns

Ler no ecrã: contributo para uma reflexão sobre estratégias de ensino da leitura na aula de Português

Resumo: A Escola assume, hoje, um papel cada vez mais ativo na formação dos (ciber)leitores, sendo chamada a reconfigurar um conjunto pré-existente de práticas em literacia onde predomina o texto impresso para um universo digital complexo, no qual o ecrã tem primazia. Assim, neste artigo procuraremos: (1) reforçar o modo como novas práticas em literacia emergem em permanência na nossa sociedade, repercutindo-se no percurso dos leitores em formação; (2) apontar para o modo como a leitura no ecrã de textos diversificados influencia a compreensão leitora, daí retirando ilações no que concerne à construção do percurso do leitor; (3) caracterizar a forma como a leitura online requer o desenvolvimento de um conjunto amplo de estratégias por parte do leitor, para que possa usufruir plenamente do prazer de ler em contexto escolar e extra-escolar. Finalmente, reflectimos criticamente sobre os desafios colocados hoje à Escola, relativamente à implementação e consolidação de percursos de leitura que estejam na base do exercício hodierno da cidadania

Advanced hydrogels for treatment of diabetes

Diabetes mellitus is a chronic disease characterized by high levels of glucose in the blood, which leads to metabolic disorders with severe consequences. Today, there is no cure for diabetes. The current management for diabetes and derived medical conditions, such as hyperglycemia, cardiovascular diseases or diabetic foot ulcer, includes life style changes and hypoglycemia based therapy, which do not fully restore euglycemia or the functionality of damaged tissues in patients. This encourages scientists to work outside their boundaries to develop routes that can potentially tackle such metabolic disorders. In this regard, acellular and cellular approaches have represented an alternative for diabetics, although such treatments still face shortcomings related to limited effectiveness and immunogenicity. The advent of biomaterials has brought significant improvements for such approaches, and three-dimensional extracellular matrix analogous, such as hydrogels, have played a key role in this regard. Advanced hydrogels are being developed to monitor high blood glucose levels and release insulin, as well as serve as a therapeutic technology. Herein, the state of the art in advanced hydrogels for improving treatment of diabetes, from laboratory technology to commercial products approved by drug safety regulatory authorities, will be concisely summarized and discussed. [Abstract copyright: This article is protected by copyright. All rights reserved.

pH-Responsive Polyketone/5,10,15,20-Tetrakis-(Sulfonatophenyl)Porphyrin Supramolecular Submicron Colloidal Structures

In this work, we prepared color-changing colloids by using the electrostatic self-assembly approach. The supramolecular structures are composed of a pH-responsive polymeric surfactant and the water-soluble porphyrin 5,10,15,20-tetrakis-(sulfonatophenyl)porphyrin (TPPS). The pH-responsive surfactant polymer was achieved by the chemical modification of an alternating aliphatic polyketone (PK) via the Paal-Knorr reaction with N-(2-hydroxyethyl)ethylenediamine (HEDA). The resulting polymer/dye supramolecular systems form colloids at the submicron level displaying negative zeta potential at neutral and basic pH, and, at acidic pH, flocculation is observed. Remarkably, the colloids showed a gradual color change from green to pinky-red due to the protonation/deprotonation process of TPPS from pH 2 to pH 12, revealing different aggregation behavior

Mercados municipales de Zapopan

Documento final del Proyecto de Aplicación Profesional en el que se presenta una investigación realizada en tres mercados del ayuntamiento de Zapopan: San Isidro, Francisco Sarabia y Tesistán. El objetivo de la investigación fue identificar las problemáticas, hacer propuestas y colaborar en la planeación de estrategias para mejorar las condiciones de los mercados y lograr un impacto positivo que se vea reflejado en las ventas. Para la investigación, se visitaron los mercados y se aplicaron encuestas a los locatarios, consumidores y administradores. La muestra que se usó para sacar el número de encuestas fue infinita con un nivel de confianza del 90 por ciento y un índice de error del 5 por ciento. En este proyecto trabajaron alumnos de las licenciaturas en Mercadotecnia, Administración de Empresas y Administración Financiera.ITESO, A.C

Volcanic Emissions and Atmospheric Pollution: A Study of Nanoparticles

The influence of emissions of an active volcano on the composition of nanoparticles and ultrafine road dust was identified in an urban area of the Andes. Although many cities are close to active volcanoes, few studies have evaluated their influence in road dust composition. Air quality in urban areas is significantly affected by non-exhaust emissions (e.g. road dust, brake wear, tire wear), however, natural sources such as volcanoes also impact the chemical composition of the particles. In this study, elements from volcanic emissions such as Si \u3e Al \u3e Fe \u3e Ca \u3e K \u3e Mg, and Si—Al with K were identified as complex hydrates. Similarly, As, Hg, Cd, Pb, As, H, Cd, Pb, V, and salammoniac were observed in nanoparticles and ultrafine material. Mineral composition was detected in the order of quartz\u3e mullite\u3e calcite\u3e kaolinite\u3e illite\u3e goethite\u3e magnetite\u3e zircon\u3e monazite, in addition to salammoniac, a tracer of volcanic sources. The foregoing analysis reflects the importance of carrying out more studies relating the influence of volcanic emissions in road dust in order to protect human health. The road dust load (RD10) ranged between 0.8 and 26.8 mg m−2 in the city

Volcanic emissions and atmospheric pollution: a study of nanoparticles

The influence of emissions of an active volcano on the composition of nanoparticles and ultrafine road dust was identified in an urban area of the Andes. Although many cities are close to active volcanoes, few studies have evaluated their influence in road dust composition. Air quality in urban areas is significantly affected by non-exhaust emissions (e.g. road dust, brake wear, tire wear), however, natural sources such as volcanoes also impact the chemical composition of the particles. In this study, elements from volcanic emissions such as Si > Al > Fe > Ca > K > Mg, and Si Al with K were identified as complex hydrates. Similarly, As, Hg, Cd, Pb, As, H, Cd, Pb, V, and salammoniac were observed in nanoparticles and ultrafine material. Mineral composition was detected in the order of quartz> mullite> calcite> kaolinite> illite> goethite> magnetite> zircon> monazite, in addition to salammoniac, a tracer of volcanic sources. The foregoing analysis reflects the importance of carrying out more studies relating the influence of volcanic emissions in road dust in order to protect human health. The road dust load (RD10) ranged between 0.8 and 26.8 mg m−2 in the city

Prebiotics, Probiotics, Synbiotics and Functional Foods in Control and Treatment of Type II Diabetes Mellitus and Colorectal Cancer

Prebiotics, probiotics and synbiotics are components that enhance human health by several mechanisms. Patients suffering from type II diabetes mellitus (T2DM) and colorectal cancer have seen benefits when treated with a prebiotic, probiotic or synbiotic therapy. These benefits include the improvement of their lipid profile, oxidative stress status, as well as the modulation of the inflammatory and immune responses. The associated benefits of prebiotic, probiotic or synbiotic functional foods have been studied, showing promising results into the prevention or control of diabetes and colorectal cancer. This novelty research provides new evidence that the use of functional foods along with medical therapy could be used to further enhance patient’s health

Using a Floating-Gate MOS Transistor as a Transducer in a MEMS Gas Sensing System

Floating-gate MOS transistors have been widely used in diverse analog and digital applications. One of these is as a charge sensitive device in sensors for pH measurement in solutions or using gates with metals like Pd or Pt for hydrogen sensing. Efforts are being made to monolithically integrate sensors together with controlling and signal processing electronics using standard technologies. This can be achieved with the demonstrated compatibility between available CMOS technology and MEMS technology. In this paper an in-depth analysis is done regarding the reliability of floating-gate MOS transistors when charge produced by a chemical reaction between metallic oxide thin films with either reducing or oxidizing gases is present. These chemical reactions need temperatures around 200 °C or higher to take place, so thermal insulation of the sensing area must be assured for appropriate operation of the electronics at room temperature. The operation principle of the proposal here presented is confirmed by connecting the gate of a conventional MOS transistor in series with a Fe2O3 layer. It is shown that an electrochemical potential is present on the ferrite layer when reacting with propane