Experimental and computational study of the effect of temperature on the electro-polymerization process of Thiophene

Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte Carlo algorithm. It reproduced key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. Electrochemical synthesis conditions at temperatures between 263 and 303 K were optimized. The deconvolution of the i-t transients reflected two contributions: a progressive nucleation with three-dimensional growth controlled by diffusion and the other by charge transfer, PN3Ddif and PN3Dct, respectively. As temperature decreased, a diminution of the charge associated to each contribution was observed and the nucleation induction time increased. Experimental and computational evidence indicated that temperature does not change the nucleation and growth mechanism (NGM). This effect was ascribed to kinetic factors rather than to film conductivity. This work contrasts simulation and experimental evidence and demonstrates how computational simulations can help to understand the electrochemical process of conducting polymers formation.Fil: Camarada, María Belén. Pontificia Universidad Católica de Chile; Chile. Universidad de Talca; ChileFil: Romero, M.. Pontificia Universidad Católica de Chile; ChileFil: Gimenez, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Schmickler, Wolfgang. Universitat Ulm; AlemaniaFil: del Valle, M. A.. Pontificia Universidad Católica de Chile; Chil

Comparación in vitro de la resistencia adhesiva microtraccional en dentina entre resina fluida auto adherente fusio liquid Dentin ®, un sistema adhesivo de grabado total y un sistema adhesivo auto grabante.

Tesis (Magíster en Odontología. Especialización en Biomateriales)INTRODUCCIÓN: La odontología estética ha tenido un gran avance en los últimos años, esto, gracias al desarrollo .constante de nuevos materiales y técnicas de adhesión que día a día van mejorando. El tratamiento restaurador de los dientes, en la actualidad se lleva a cabo, gracias a la interacción entre el material restaurador y la estructura dentaria, mediante el uso de un sistema adhesivo, lo que permite que tanto mecánica, biológica y funcionalmente el diente y su material restaurador, funcionen como una unidad (Camps Alemany 1, 2004). Durante los últimos 10 años las resinas compuestas y los agentes adhesivos para dentina y esmalte han tenido una notable evolución. En la actualidad se describen 5 categorías de agentes adhesivos, 4ta, 5ta, 6ta (tipo 1y 11) Y 7ma generación. En el· caso de los agentes de 6ta y 7ma generación, la necesidad de un grabado ácido de la estructura dentaria está suprimida y por lo tanto comparados con las generaciones anteriores estos serian menos sensibles a la técnica. A lo largo de la evolución de las resinas compuestas, estos materiales siempre han tenido que contar con agentes adhesivos que permita su unión con la estructura dentaria, esto hace poco, ya que actualmente se encuentra disponible la primera resina fluida auto adherente. Este avance conlleva a un material restaurador que requiere menos pasos en su aplicación y por lo tanto ser menos sensible a la técnica que las resinas compuestas disponibles hoy en día

Relação entre dopagem no futebol e indicadores socioeconómicos globais

Em 1960 foram implementadas várias medidas no combate ao doping no desporto, designadamente a introdução de procedimentos para controlos antidopagem e a criação de uma lista por parte da World Anti-Doping Agency (WADA). Esta entidade revolucionou toda a estratégia na luta contra a dopagem (Ljungqvist, 2017). Atualmente, o consumo de substâncias dopantes é um dos grandes problemas da realidade desportiva. O objetivo deste estudo é compreender a relação entre diversos indicadores socioeconómicos globais e os casos positivos de doping no futebol em todos os países do mundo. Metodologicamente, recorremos a métodos quantitativos. Através de fontes oficiais, recolhemos os dados de todos os indicadores socioeconómico previamente definidos e dos casos positivos de doping. Realizámos vários procedimentos estatísticos, designadamente estatística descritiva, testes de hipóteses, correlações e análise de Variância (One-Way ANOVA). Nos resultados, através dos procedimentos estatísticos, aferimos que os indicadores com maiores médias são o índice capital humano (65,05) e o índice de corrupção (41,93), significando que estes indicadores são os mais importantes para os países. Verificamos, também, que existem mais países sem casos positivos (n=126) do que países com casos positivos de doping (n=58). O Sig (2 extremidades) apresenta um p < 0.05, logo, o teste de t de Student mostra diferenças estatisticamente significativas entre todas as variáveis analisadas e o número de casos de doping,à exceção da taxa de desemprego e do coeficiente de Gini para um intervalo de confiança de 95%. Concluímos que quanto maior o capital o humano e a perceção da corrupção menor o consumo de doping. Aferimos também que quanto maior o índice de desenvolvimento humano e o índice de felicidade, maior o consumo de doping. A taxa de desemprego e o coeficiente de Gini não mostraram qualquer diferença estatística; The relationship between doping in football and global socioeconomic indicators ABSTRACT: In 1960 were implemented several measures to combat doping in sport, namely in the introduction of anti-doping procedures and the creation of a list of parts of the World Anti-Doping Agency (WADA). This entity there was a revolution in anti-doping strategy (Ljungqvist, 2017). Currently, the consumption of doping substances is one of the major problems of the sports reality. This study has the goal to understand the relationship between several global socio-economic indicators and positive cases of doping in football in all countries of the world. Methodologically, we use quantitative method. Through official sources, we collect data for all socio-economic indicators defined above and positive cases of doping. Various statistical procedures were performed, such as descriptive statistics, hypothesis tests, correlations and analysis of variance (One-Way ANOVA). In the results, through statistical procedures, we found that the indicators with the highest averages are the human capital index (65.05) and the corruption index (41.93), meaning that these indicators are the most important for countries. We also found that there are more countries without positive cases (n=126) than countries with positive cases of doping (n=58). The Sig (2 extremities) presents a p < 0.05, so the Student's t test shows statistically significant differences between all variables analyzed and the number of doping cases, except for the unemployment rate and Gini coefficient for a 95% confidence interval. We conclude that the greater the human capital and the perception of corruption, the lower the consumption of doping. We also measured that the higher the Human development index and happiness index, the higher the doping consumption. The unemployment rate and Gini coefficient did not show any statistical difference; Relación entre el dopaje en el fútbol y los indicadores socioeconómicos mundiales. RESUMEN: En 1960 fueron implementado varias medidas para combatir el dopaje en el deporte, a saber, la introducción de procedimientos para los controles de dopaje y la creación de una lista por la Agencia Mundial Antidopaje (AMA). Esta entidad a revolucionado toda la estrategia de la lucha contra el dopaje (Ljungqvist, 2017). Actualmente, el consumo de sustancias dopantes es uno de los principales problemas de la realidad deportiva. El objetivo de este estudio es comprender la relación entre los varios indicadores socioeconómicos globales y los casos positivos de dopaje en el fútbol en todos los países del mundo. Metodológicamente, utilizamos métodos cuantitativos. Mediante de fuentes oficiales, recopilamos datos para todos los indicadores socioeconómicos previamente definidos y casos positivos de dopaje. Realizamos varios procedimientos estadísticos, en particular, estadística descriptiva, pruebas de hipótesis, correlaciones y análisis de varianza (ANOVA de una vía). En los resultados, los indicadores con los promedios más altos son el índice de capital humano (65.05) y el índice de corrupción (41.93), lo que significa que estos indicadores son los más importantes para los países. También constatamos que hay más países sin casos positivos (n=126) que países con casos positivos de dopaje (n=58). El Sig (2 extremidades) presenta una p < 0.05, por lo que la prueba t del Estudiante muestra diferencias estadísticamente significativas entre todas las variables analizadas y el número de casos de dopaje, excepto para la tasa de desempleo y el coeficiente de gini para un intervalo de confianza del 95%. Concluimos que cuanto mayor sea el capital humano y la percepción de la corrupción, menor será el consumo de dopaje. También medimos que cuanto mayor sea el índice de Indice de desarrollo humano y felicidad, mayor será el consumo de dopaje. La tasa de desempleo y el coeficiente de gini no mostraron ninguna diferencia estadístic

Estudo da microbiota láctica em leites fermentados artesanalmente consumidos no sul de Angola

Tese de Doutoramento em Ciências Veterinárias. Especialidade Segurança AlimentarO omavele é um leite fermentado artesanalmente produzido pelas populações pastoris do sul e sudoeste de Angola. Os leites fermentados artesanalmente constituem uma parte importante da dieta das populações africanas e, para além de fornecerem nutrientes, têm a vantagem de se conservarem por longos períodos de tempo devido ao baixo pH e à presença de compostos que inibem o desenvolvimento tanto de microrganismos patogénicos como dos de decomposição. O processo de fabrico do omavele consiste em colocar o leite de vaca, imediatamente depois da ordenha, numa cabaça contendo ou não raízes ou cascas de plantas para acelerar a sua coagulação e a formação do “ngundi”. A fermentação decorre em cerca de 9 horas à temperatura ambiente. O objetivo do nosso estudo foi caracterizar a microbiota láctica presente no omavele de produção artesanal, para se poderem produzir fermentos que serão utilizados na produção industrial do omavele. Analisou-se a composição química e a qualidade higio-sanitária do omavele tradicional. Nas 57 amostras de omavele colhidas em diferentes localidades da província da Huíla os teores médios microbianos foram: Lactobacilos (6,8 log10 ufc/mL), Lactococos (6,24 log10 ufc/mL), Leveduras (5,82 log10 ufc/mL), Enterococos (4,48 log10 ufc/mL), Micrococos (3,74 log10 ufc/mL), Enterobactérias (3,26 log10 ufc/mL) e Aeróbios totais a 30ºC (6,31 log10 ufc/mL). A identificação genética de 141 isolados, por técnicas de biologia molecular, revelou que as espécies mais identificadas foram Lb. plantarum/Lb. pentosus (31,20%), Lb. casei/Lb. paracasei (7,09%), Lb. plantarum (4,34%), Kazachstania unispora (9,92%), Saccharomyces cerevisiae (8,51%) e Issatchenkia orientalis (8,51%). Foram selecionadas estirpes para se constituírem três fermentos (FO1, FO2 e FO3) que foram usados para a produção industrial de três leites fermentados (O1, O2 e O3), cuja avaliação microbiológica 30 dias pós-produção revelou teores de microrganismos viáveis ≥ 7 log10 ufc/mL, demonstrando uma boa capacidade de sobrevivência ao processamento industrial. Após avaliação sensorial o omavele O1 foi o eleito entre os 3 leites produzidos.ABSTRACT - Study of lactic microbiota in fermented milk consumed in the south of Angola - The omavele is a fermented milk produced by artisan shepherd populations of the south and southwest Angola. The handmade fermented milks are an important part of the diet of African populations. In addition to providing nutrients they have the advantage of long shelf life due to the low pH and the presence of compounds that inhibit the growth of both pathogenic and spoilage microorganisms. The manufacturing process of omavele involves placing the cow’s milk, immediately after milking, in a gourd containing or not roots or bark of a plant to accelerate the coagulation and the formation of “ngundi”. Fermentation takes place in about 9 hours at room temperature. The aim of our study was to characterize the lactic microbiota present in handmade omavele, to be able to produce yeasts that will be used in the industrial production of omavele. We analyzed the chemical composition and the hygienic quality of traditional handmade omavele. In 57 omavele samples collected in different localities of Huíla province the microbial average counts were: Lactobacillus (6,8 log10 cfu/mL), Lactococci (6,24 log10 cfu/mL), Yeast (5,82 log10 cfu/mL), Enterococci (4,48 log10 cfu/mL) Micrococci (3,74 log10 cfu/mL), Enterobacteriaceae (3,26 log10 cfu /mL) and Total Aerobes at 30 ° C (6,31 log10 cfu/mL). The genetic identification of 141 isolates by techniques of molecular biology has shown that most species were Lb. plantarum / Lb. pentosus (31,20%), Lb. casei / Lb. paracasei (7,09%), Lb. plantarum (4,34%), Kazachstania unispora (9,92%), Saccharomyces cerevisiae (8,51%) and Issatchenkia orientalis (8,51%). Strains were selected to constitute three yeasts (FO1, FO2 and FO3) that were used for the industrial production of three fermented milks (O1, O2 and O3), whose microbiological evaluation 30 days after production revealed levels of viable microorganisms ≥ 7 log10 cfu/mL, demonstrating a good ability for industrial processing. After the sensory evaluation omavele O1 has been selected among the 3 milks produced

A first approximation to simulate the electro-polymerization process

With the aim of understanding the nucleation and growth mechanism of thiophene, a new computational simulation method based on a kinetic Monte Carlo algorithm was designed. It reproduces key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. This paper describes all simulation details, reports the first computational results and contrasts them with previously published electro-polymerization evidence. The results agree well with experimental studies and demonstrate how computational simulations can help to understand the electrochemical process of conducting polymers formation.Fil: Camarada, María Belén. Pontificia Universidad Católica de Chile. Facultad de Física; Chile. Universidad Católica de Chile; ChileFil: Gimenez, Maria Cecilia. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Schmickler, Wolfgang. Universitat Ulm; AlemaniaFil: del Valle, M. A.. Pontificia Universidad Católica de Chile. Facultad de Física; Chil

Synthesis and characterization of graphene/polythiophene (GR/PT) nanocomposites:Evaluation as high-performance supercapacitor electrodes

Composites of polythiophene (PT) and graphene (GR) with different mass proportions were studied for their application as supercapacitors. Fourier transform infrared spectroscopy (FTIR) along with High Resolution Scanning electron microscopy (HR-SEM) were employed in order to characterize the morphology and composition of the resulting composites. The electrochemical behaviour of these composites was studied by means of cyclic voltammetry and specific capacitance curves were derived from these measurements. The Faradaic impedance spectroscopy response of the different composites, along with that of GR, was also studied. From these measurements it was found that a 1:1 in mass composite of GR and PT showed a higher specific capacitance, even when compared with GR alone. The introduction of the GR in that proportion also showed an enhanced cyclic stability in comparison with the sole polymer. The high specific capacitance (365 F g-1 at 1 A g-1) of this composite material indicates its potential for use as an electrode material for supercapacitors.Fil: Melo, J. P.. Universidad Bernardo OHiggins; ChileFil: Schulz, Eduardo Nicolás. Universidad Nacional del Sur. Departamento de Ingeniería Química. Instituto de Ingeniería Electroquímica y Corrosión; Argentina. University of Birmingham; Reino UnidoFil: Morales Verdejo, C.. Universidad Bernardo OHiggins; ChileFil: Horswell, S. L.. University of Birmingham; Reino UnidoFil: Camarada, M. B.. Universidad Bernardo OHiggins; Chil

Synthesis, Characterization, Morphology and Photovoltaic Properties of Aniline-Tiophene Based Polymers

Monomers composed of thiophene and aniline rings, 4-(2-thiophen)aniline and 4-(3-thiophen)aniline, were successfully synthetized through the Suzuki-Miyaura cross coupling reaction and then polymerized. The polymers poly 4-(2-tiophen)aniline and poly 4-(3-tiophen)aniline (P4,2TA and P4,3TA) were characterized via spectroscopycal NMR, optical and electrochemical methodologies. Subsequently the morphology of deposits were characterized using atomic force microscopy (AFM) and X-ray diffraction (XRD). The photovoltaic devices were constructed under the same conditions, observing differences in the photovoltaic yield of each polymer. P4,2TA exhibited higher photovoltaic yield in comparison with P4,3TA, indicating that the molecular geometry affects the crystallinity and surface morphology of the polymeric deposits, and the photovoltaic propertie

Self-Assembly of Amphiphilic Dendrimers: The Role of Generation and Alkyl Chain Length in siRNA Interaction

Citation: Marquez-Miranda, V., Araya-Duran, I., Camarada, M. B., Comer, J., Valencia-Gallegos, J. A., & Gonzalez-Nilo, F. D. (2016). Self-Assembly of Amphiphilic Dendrimers: The Role of Generation and Alkyl Chain Length in siRNA Interaction. Scientific Reports, 6, 15. https://doi.org/10.1038/srep29436An ideal nucleic-acid transfection system should combine the physical and chemical characteristics of cationic lipids and linear polymers to decrease cytotoxicity and uptake limitations. Previous research described new types of carriers termed amphiphilic dendrimers (ADs), which are based on polyamidoamine dendrimers (PAMAM). These ADs display the cell membrane affinity advantage of lipids and preserve the high affinity for DNA possessed by cationic dendrimers. These lipid/dendrimer hybrids consist of a low-generation, hydrophilic dendron (G2, G1, or G0) bonded to a hydrophobic tail. The G2-18C AD was reported to be an efficient siRNA vector with significant gene silencing. However, shorter tail ADs (G2-15C and G2-13C) and lower generation (G0 and G1) dendrimers failed as transfection carriers. To date, the self-assembly phenomenon of this class of amphiphilic dendrimers has not been molecularly explored using molecular simulation methods. To gain insight into these systems, the present study used coarse-grained molecular dynamics simulations to describe how ADs are able to self-assemble into an aggregate, and, specifically, how tail length and generation play a key role in this event. Finally, explanations are given for the better efficiency of G2/18-C as gene carrier in terms of binding of siRNA. This knowledge could be relevant for the design of novel, safer ADs with well-optimized affinity for siRNA

Highly modulated supported triazolium-based ionic liquids: direct control of the electronic environment on Cu nanoparticles

A series of new triazolium-based supported ionic liquids (SILPs), decorated with Cu NPs, were successfully prepared and applied to the N-arylation of aryl halides with anilines. The triazoles moieties were functionalised using copper-catalysed azide–alkyne cycloaddition. SILP surface characterisation showed a strong correlation between the triazolium cation volume and textural properties. STEM images showed well-dispersed Cu NPs on SILPs with a mean diameter varying from 3.6 to 4.6 nm depending on the triazolium cation used. Besides, XPS results suggest that the Cu(0)/Cu(I) ratio can be modulated by the electronic density of triazolium substituents. XPS and computational analysis gave mechanistic insights into the Cu NP stabilisation pathways, where the presence of electron-rich groups attached to a triazolium ring plays a critical role in leading to a cation adsorption pathway (Eads = 72 kcal mol−1). In contrast, less electron-rich groups favour the anion adsorption pathway (Eads = 63 kcal mol−1). The Cu@SILP composite with electron-rich groups showed the highest activity for the C–N Ullmann coupling reaction, which suggests that electron-rich groups might act as an electron-like reservoir to facilitate oxidative addition for N-arylation. This strategy firmly suggests the strong dependence of the nature of triazolium-based SILPs on the Cu NP surface active sites, which may provide a new environment to confine and stabilise MNPs for catalytic applications

Motivação para a prática de futebol em quatro divisões portuguesas

O objetivo do presente estudo foi comparar a motivação para a prática de futebol em jogadores seniores de diferentes divisões de campeonatos em Portugal. Partici param no estudo 80 Jogadores de futebol do sexo masculino entre os 18 e os 40 anos de idade (média 28.6 anos), preenchendo o questionário de Orientação Moti vacional no Desporto (QOMD), específico para atletas, uma versão do Task and Ego Orientation in Sport Questionnaire (TEOSQ). O questionário é constituído por 13 questões, 7 das quais com motivação assente na tarefa e 6 no ego. Conclu iu-se que no futebol, os jogadores atribuem particular grau de concordância à motivação com base na tarefa. Verificou-se nos jogadores do clube a disputar a divisão superior de futebol (2.ª liga), os maiores valores de concordância relativa mente a motivação com base no ego, um aspeto que consideramos preocupante ao nível da autodeterminação, situação que coloca em causa a médio-longo prazo a manutenção de envolvimento em prática desportiva. Futuramente, será fundamen tal pocurar compreender as motivações para a prática desportiva no sentido de procurar “guiar” os praticantes para o correto envolvimento para a prática.The aim of the present study was to compare the motivation for the practice of soccer in senior players of different divisions in Portugal leagues. 80 male soccer players between 18 and 40 years of age (average 28.6) participated in the study, completing the questionnaire on Motivation in Sport (QOMD), specific for ath letes, a version of Task and Ego Orientation in Sport Questionnaire (TEOSQ). The questionnaire consists of 13 questions, 7 of which are motivated by the task and 6 are in the ego. It was concluded that in soccer in Portugal, the players attribute a particular degree of agreement to the motivation based on the task. Club players compete in the top division of football (2nd league), presented the highest values of agreement on ego-based motivation, an aspect that is attributed to notoriety and visibility, and we consider it disturbing at the level of self-determination, a situa tion that puts in question in the medium-long term the maintenance of involvement in sports practice. Seeking to understand the motivations for sports practice is a fundamental aspect in the sense of seeking to "guide" the practitioners in the sense of the correct involvement for the practice.info:eu-repo/semantics/publishedVersio