Nanofibras de isolado proteico de bijupirá (rachycentron canadum): desenvolvimento, caracterização e avaliação toxicológica

As nanofibras produzidas através de biopolímeros oriundos de materiais biológicos têm tomado espaço no âmbito mundial, estes podem ter sua origem em compostos como a proteína animal, por exemplo, as proteínas de pescado. O presente trabalho teve como objetivo geral desenvolver nanofibras de isolado proteico de Bijupirá (Rachycentron canadum). O isolado proteico de bijupirá (IPB) foi obtido utilizando processo de variação de pH para solubilizar e isolar proteínas. O IPB obtido foi caracterizado quanto sua composição química proximal e suas propriedades físicoquímicas, estruturais e funcionais. O rendimento do IPB foi de 98,17% de proteína, em base seca. A maior solubilidade e a maior capacidade de retenção de água (CRA) do IPB foram obtidas em pH 11 e 21,9 mL.g-1 de proteína, respectivamente. Os perfis eletroforéticos revelaram massas moleculares características de proteínas miofibrilares (miosina e actina). Os principais picos identificados pelas análises de Espectroscopia na Região do Infravermelho (FTIR) são provenientes de ligações peptídicas (ligações amida), como Amida I e II. Os maiores pontos de fusão e de degradação do IPB foram de 259,1°C e 378°C, respectivamente, obtendo assim, um isolado proteico com elevada estabilidade térmica. As nanofibras foram desenvolvidas pela técnica de electrospinnig. Foram preparadas soluções poliméricas utilizando 1% (p/v) de óxido de polietileno (PEO) e 1, 2, 3, 4, 5 e 6% (p/v) de IPB. Os parâmetros utilizados no processo de electrospinning como: potencial elétrico, distância da ponta do coletor a agulha e a taxa de fluxo da solução foram fixados em 16,7 kV, 15 cm, e 150 µL.h-1 , respectivamente. Os efeitos do solvente e a adição de um biopolímero comercial na capacidade de formação e morfologia das nanofibras foram estudados. Em relação ao efeito do solvente na solubilização das proteínas, o processo de electrospinning foi favorecido quando utilizado o ácido fórmico 85% (v/v), como este solvente orgânico promove a formação de estruturas helicoidais aleatórias e, consequentemente, um aumento no emaranhado de biopolímeros. A adição do biopolímero PEO proporcionou melhor viscosidade às soluções de IPB e o desenvolvimento das nanofibras. A morfologia analisada por Microscopia eletrônica de Varredura (MEV) das nanofibras obtidas com 5 e 4% (p/v) de IPB e 1% (/v) de PEO foi de 205 ± 82 nm e 476 ± 107, respectivamente.

CD81 interacting proteins

Fertilization is a multistep and complex process culminating in the merge of gamete membranes, cytoplasmic unity and fusion of genome. CD81 is a tetraspanin protein that participates in sperm-oocyte interaction, being present at the oocyte surface. CD81 has also been implicated in other biological processes, however its specific function and molecular mechanisms of action remain to be elucidated. The interaction between CD81 and its binding partner proteins may underlie the CD81 involvement in a variety of cellular processes and modulate CD81/interactors specific functions. Interestingly, in a Yeast two Hybrid system previously performed in our lab, CD81 has emerged as a putative interactor of the Amyloid Precursor Protein (APP). In the work here described, bioinformatics analyses of CD81 interacting proteins were performed and the retrieved information used to construct a protein-protein interaction network, as well as to perform Gene Ontology enrichment analyses. CD81 expression was further evaluated in CHO, GC-1 and SH-SY5Y cell lines, and in human sperm cells. Additionally, its subcellular localization was analyzed in sperm cells and in the neuronal-like SH-SY5Y cell line. Subsequently, coimmunoprecipitation assays were performed in CHO and SH-SY5Y cells to attempt to prove the physical interaction between CD81 and APP. A functional interaction between these two proteins was accessed thought the analyses of the effects of CD81 overexpression on APP levels. A co-localization analysis of CD81 and some interactors proteins retrieved from the bioinformatics analyses, such as APP, AKT1 and cytoskeleton-related proteins, was also performed in sperm cells and in SH-SY5Y cells. The effects of CD81 in cytoskeleton remodeling was evaluated in SH-SY5Y cells through monitoring the effects of CD81 overexpression in actin and tubulin levels, and analyzing the colocalization between overexpressed CD81 and F-actin. Our results showed that CD81 is expressed in all cell lines tested, and also provided the first evidence of the presence of CD81 in human sperm cells. CD81 immunoreactivity was predominantly detected in the sperm head, including the acrosome membrane, and in the midpiece, where it co-localized with APP, as well as in the post-acrosomal region. Furthermore, CD81 co-localizes with APP in the plasma membrane and in cellular projections in SH-SY5Y cells, where CD81 overexpression has an influence on APP levels, also visible in CHO cells. The analysis of CD81 interacting proteins such as AKT1 and cytoskeletonrelated proteins showed that CD81 is involved in a variety of pathways that may underlie cytoskeleton remodeling events, related to processes such as sperm motility, cell migration and neuritogenesis. These results deepen our understanding on the functions of CD81 and some of its interactors in sperm and neuronal cells.

Bioatividade de Líquidos Iónicos Derivados do Valproato na Osteoclastogénese Humana e Estudo do Efeito Antomicrobiano dos Catiões Utilizados

Os Líquidos Iónicos (LIs) são compostos iónicos com pontos de fusão abaixo de 100°C, muitos deles são líquidos à temperatura ambiente. As numerosas combinações entre o catião e anião permitem modular as suas propriedades físico-químicas. A associação entre LIs e Ingredientes Farmacêuticos Ativos (IFAs) tem sido estudada e revelou que esta combinação reduz os efeitos secundários dos fármacos e aumenta a sua biodisponibilidade. A resistência bacteriana é um problema na sociedade moderna. Por esse motivo, é crucial pesquisar novos alvos terapêuticos para superar esta situação. O Ácido Valpróico (VPA) é um fármaco anti-epiléptico muito utilizado no tratamento de doenças neurológicas, mas que possui vários efeitos secundários associados, afetando principalmente a remodelação óssea. A combinação de LIs e IFAs – LIs-IFAs – tem demostrado que estes compostos podem ser úteis para ultrapassar a resistência bacteriana, bem como os problemas que os pacientes sujeitos ao tratamento com VPA experienciam. O objetivo deste estudo é determinar a bioatividade de LIs-IFAs, tanto em estirpes de bactérias, como em células do osso – osteoclastos (humanos). No estudo bacteriano, a Ampicilina de Sódio e vários catiões halogenados foram aplicados em estirpes bacterianas, nas quais estavam incluídas algumas estirpes resistentes, e foram determinadas as suas taxas de crescimento. No estudo osteoclastogénico, foram usados vários catiões associados com valproato que, posteriormente, foram aplicados em culturas de células osteoclásticas humanas para determinar o seu efeito nestas células. Os LIs-IFAs mostraram efeitos inibitórios em ambos os estudos. No estudo antimicrobiano o [C16Pyr] [Cl] associado à Ampicilina de Sódio revelou inibição das estirpes sensíveis e de bactérias resistentes. Na avaliação do processo osteoclastogénico, o [C2OHDMIM] [Valproato] e [C6,6,6,14P] [Valproato] demonstraram capacidade de modular negativamente este processo. Os resultados obtidos no presente trabalho destacam o potencial destes compostos como novos fármacos, e a importância de outros estudos para compreender os mecanismos pelos quais eles atuam, tanto em células como em bactérias.

A importância das redes de relacionamento para se formar uma parceria : um estudo de caso na ALESAT

This paper consists in a study case at the Alesat company, which aims at analyzing how the networks from the former companies Ale and Sat influence the formation of partnerships. The study was based on literature by Burt (1992), Granovetter (1973), Uzzi (1997), Contractor and Lorange (1988), Gulati (1998), Child and Faulkner (1998), and others, to verify how important the social relations were between the companies to the formation of a strategic alliance. The research method we adopted analyzed the first partnership between Ale and Sat and the last one that ended up with the merger of the companies resulting in a new company, Alesat. Semi-structured interviews were conducted in 2008 with the council board of the company. Secondary data were also collected from specific web sites from the area, such as ANP, Sindicom and Fecombustíveis, as well as from important newspapers in the market. The primary data were analyzed through the content analysis technique from Triviños (1987). The secondary data were analyzed through the documental analysis technique from Richardson (1985). This way, through the data collected, it can be concluded that the social ties between the companies were important in the partnership, and among the reasons that made the companies get together, the key one was the fact that the union would make possible to the companies act in regions in which they didn t have too much market share, making them a bigger player nationally wise

Fusões e aquisições no Brasil: Uma análise crítica do teatro de operações

Fusões e aquisições estão entre as mais relevantes e dramáticas formas de transformação organizacional. Porém, muitos destes processos falham, resultando em traumas e destruição de valor. Isto faz crer que as razões que contribuem para o seu sucesso não são bem entendidas ou não são praticadas. Este artigo apresenta uma pesquisa exploratória realizada sobre 53 casos de fusões e aquisições que ocorreram no Brasil entre 1996 e 2000. O estudo sugere que a forma como o processo de fusão ou aquisição é conduzido – incluindo medidas como foco na comunicação, redução de demissões ao mínimo e desenvolvimento de atitude de respeito aos funcionários – contribui de forma efetiva para melhores resultados. Este artigo também apresenta uma proposta de tipologia para abordagens reducionistas e discute prováveis razões para sua adoção em processos de fusão ou aquisição.

Das raízes

O objetivo deste projeto artístico foi desenvolver um conhecimento mais aprofundado relacionado com a execução e interpretação de técnicas de percussão tradicionais aliadas a técnicas contemporâneas. De entre as várias técnicas tradicionais de percussão optei por desenvolver as da percussão Africana (Guiné e Burkina Faso, e mais tarde Nigéria) e as da percussão Cubana. Criei assim um projeto artístico de fusão intitulado Das Raízes, no qual ao longo dos dois anos do curso de mestrado estive em contacto com a música Africana e Cubana aliada a técnicas contemporâneas e composições originais (minhas e de outros compositores). Para cada obra explorei primeiro as técnicas tradicionais e em seguida adaptei-as à percussão contemporânea, num processo onde as suas raízes africanas, cubanas ou até afro- cubanas são evidentes. Neste projeto salienta-se o papel preponderante das mãos. No século XXI o uso da baqueta predomina como a técnica mais forte para dominar os instrumentos nos conservatórios e nas escolas superiores de música. Após ter adquirido esta técnica resolvi aprofundar as técnicas tradicionais onde predominam o uso não só da baqueta mas também da mão, um mundo antigo na sua existência, mas novo para mim. Espero poder transportar o ouvinte para um mundo em que cor, movimento e som, antiguidade e contemporaneidade estão em constante vibração.

Production of biodiesel through esterification catalysed by Ionic liquids

Biodiesel is an alternative diesel fuel that is produced from vegetable oils and animal fats. Currently, most biodiesel is made from oils, methanol, and an alkaline catalyst. Conventional catalysts is commonly used for catalyzing esterification of fatty acid to produce biodiesel. However, a better and greener method was found. An ionic liquid (IL) is a molten salt consisting of a cation and an anion, with low melting temperature. It offers a better solution than sulfuric acid, because it can be recycled and reused in subsequent runs after recovery steps. In this study, a Brønsted acidic IL, 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM][HSO4]) was used as a catalyst in the esterification of oleic acid with methanol into biodiesel. The effect of different operation parameters such as methanol to oil molar ratio, amount of catalyst, reaction temperature, and reaction time were tested. The optimum conditions for esterification of oleic acid were identified as oleic acid/methanol molar ratio of 1/10, amount of catalyst 10 wt%, reaction time of 4 h, and reaction temperature of 90oC. FAME content of produced biodiesel was analyzed and confirmed using GC chromatography.

Studies on terpenes solubility in water and deep eutectic solvents diagrams for biomedical applications

The main objectives of this work are the measurement of terpenes solubility in water at different temperatures, and the formulation of Deep Eutectic Solvents based on choline chloride and polycarboxylic acids, that can be used as hydrotropes of aqueous solutions in terpenes, replacing conventional organic solvents. In this work a new experimental methodology was implemented, using dialysis membranes, for the measurement of terpenes solubility in water. Concerning the deep eutectic diagrams formulation, the determination of the melting points of the eutectic mixtures was performed using a visual method. The method used for determining solubilities was previously validated using a well-studied model compound, toluene. The experimental results of terpenes solubilities in water resulted in a very satisfactory coefficients of variation, always below 6%. The experimental solubility data were analysed and the temperature dependence is also studied in a thermodynamic perspective. The compound with the largest solubility dependence with the temperature is geraniol, while thymol presents the smallest. The phase diagrams of DES formulated were quite satisfactory, presenting always eutectic points below to 373.15 K. For some compositions, the systems composed by choline chloride and lactic, or malonic, or myristic acid were liquid at room temperature. In the case of monocarboxylic acids, eutectic is formed at 60% mol of the acid, to dicarboxylic acid is formed at 50% mol of the acid and for tricarboxylic acid these point is formed at 30% mol of the acid. In the future, it will be important to study the effect of DES as hydrotropes in aqueous solutions of terpenes. Furthermore, it would be interesting to study more terpenes in order to assess the effect of the size of the alkyl chain and the structures of the compounds.

Estudo da síntese e sinterização de pós compósitos do sistema Ta-Cu

Ta-Cu bulk composites combine high mechanical resistance of the Ta with high electrical and thermal conductivity of the Cu. These are important characteristics to electrical contacts, microwave absorber and heat skinks. However, the low wettability of Ta under Cu liquid and insolubility mutual these elements come hard sintering this composite. High-energy milling (HEM) produces composite powders with high homogeneity and refines the grain size. This work focus to study Ta-20wt%Cu composite powders prepared by mechanical mixture and HEM with two different conditions of milling in a planetary ball mill and then their sintering using hydrogen plasma furnace and a resistive vacuum furnace. After milling, the powders were pressed in a steel dye at a pressure of 200 MPa. The cylindrical samples pressed were sintered by resistive vacuum furnace at 10-4torr with a sintering temperature at 1100ºC / 60 minutes and with heat rate at 10ºC/min and were sintered by plasma furnace with sintering temperatures at 550, 660 and 800ºC without isotherm under hydrogen atmosphere with heat rate at 80ºC/min. The characterizations of the powders produced were analyzed by scanning electron microscopy (SEM), x-ray diffraction (XRD) and laser granulometry. After the sintering the samples were analyzed by SEM, XRD and density and mass loss tests. The results had shown that to high intense milling condition produced composite particles with shorter milling time and amorphization of both phases after 50 hours of milling. The composite particles can produce denser structure than mixed powders, if heated above the Cu melting point. After the Cu to arrive in the melting point, liquid copper leaves the composite particles and fills the pores

Estudo de sistemas vítreos para infiltração em alumina

The system in-Ceram Alumina, produced by VITA, consists in a technique of prepare of a substructure of ceramics to dental crowns. First burning is made in the alumina decanted by slip casting process under a stone die that reproduces the tooth prepared to receive a crown. In a second burning, alumina is infiltrated by vitreous system, giving to this set a high mechanic resistance. In this work, it s made a study of the composition of a new infiltrating material more used nowadays, giving to alumina desirable mechanics proprieties to its using like substructure of support to ceramic s crown used in the market today. The addition of Lanthanum oxide (frit A) and calcium oxide (frit B) was made in attempt to increase the viscosity of LZSA and to reduce fusion temperature. The frits were put over samples of alumina and took to the tubular oven to 1400ºC under vacuum for two groups (groups 1 and 2). For another two groups (groups 3 and 4) it was made a second infiltration, following the same parameters of the first. A fifth group was utilized like group of control where the samples of pure alumina were not submitted to any infiltrating process. Glasses manifested efficient both in quality and results of analysis of mechanic resistance, being perfectly compatible with oral environment in this technical requisite. The groups that made a second infiltration had he best results of fracture toughness, qualify the use in the oral cavity in this technical question. The average of results achieved for mechanic resistance to groups 1, 2, 3, 4 and 5 were respectively 98 MPa, 90 MPa, 144 MPa, 236 MPa and 23 MPa

Adição de vermiculita expandida mícron em pastas de baixa densidade para cimentação de poços de petróleo

The northeastern region of Brazil has a large number of wells producing oil using a method of secondary recovery steam injection, since the oil produced in this region is essentially viscous. This recovery method puts the cement / coating on thermal cycling, due to the difference in coefficient of thermal expansion between cement and metal coating causes the appearance of cracks at this interface, allowing the passage of the annular fluid, which is associated with serious risk socioeconomic and environmental. In view of these cracks, a correction operation is required, resulting in more costs and temporary halt of production of the well. Alternatively, the oil industry has developed technology for adding new materials in cement pastes, oil well, providing high ductility and low density in order to withstand the thermo-mechanical loads generated by the injection of water vapor. In this context, vermiculite, a clay mineral found in abundance in Brazil has been applied in its expanded form in the construction industry for the manufacture of lightweight concrete with excellent insulation and noise due to its high melting point and the presence of air in their layers lamellar. Therefore, the vermiculite is used for the purpose of providing low-density cement paste and withstand high temperatures caused by steam injection. Thus, the present study compared the default folder containing cement and water with the folders with 6%, 8% and 10% vermiculite micron conducting tests of free water, rheology and compressive strength where it obtained the concentration of 8 % with the best results. Subsequently, the selected concentration, was compared with the results recommended by the API standard tests of filtered and stability. And finally, analyzed the results from tests of specific gravity and time of thickening. Before the study we were able to make a folder with a low density that can be used in cementing oil well in order to withstand the thermo-mechanical loads generated by steam injection

Caracterização de compósitos Nb-20%cu obtidos por moagem de alta energia e sinterizados por fase líquida

In this work, was studied the formation of a composite of the refractory metal niobium with copper, through the process of high-energy milling and liquid phase sintering. The HEM can be used to synthesize composite powders with high homogeneity and fine size particle distribution. It may also produce the solid solubility in immiscible systems such as Nb-Cu, or extend the solubility of systems with limited solubility. Therefore, in the immiscible system Cu-Nb, the high-energy milling was successfully used to obtain the composite powder particles. Initially, the formation of composite particles during the HEM and the effect of preparation technique on the microstructure of the material was evaluated. Four loads of Nb and Cu powders containing 20%wt Cu were synthesized by MAE in a planetary type ball mill under different periods of grinding. The influence of grinding time on the metal particles is evaluated during the process by the withdrawal of samples at intermediate times of milling. After compaction under different forces, the samples were sintered in a vacuum furnace. The liquid phase sintering of these samples prepared by HEM produced a homogeneous and fine grained. The composite particles forming the sintered samples are the addition of a hard phase (Nb) with a high melting point, and a ductile phase (Cu) with low melting point and high thermal and electrical conductivities. Based on these properties, the Nb-Cu system is a potential material for many applications, such as electrical contacts, welding electrodes, coils for generating high magnetic fields, heat sinks and microwave absorbers, which are coupled to electronic devices. The characterization techniques used in this study, were laser granulometry, used to evaluate the homogeneity and particle size, and the X-ray diffraction, in the phase identification and to analyze the crystalline structure of the powders during milling. The morphology and dispersion of the phases in the composite powder particles, as well the microstructures of the sintered samples, were observed by scanning electron microscopy (SEM). Subsequently, the sintered samples are evaluated for density and densification. And finally, they were characterized by techniques of measuring the electrical conductivity and microhardness, whose properties are analyzed as a function of the parameters for obtaining the composite

Literatura para a infância no jardim de infância: contributos para o desenvolvimento da criança em idade pré-escolar

Pretende-se, no presente artigo, demonstrar que, nos livros para crianças, a relação dialogal e a fusão intersemiótica entre as linguagens verbal e icónica potenciam a instauração de uma atmosfera poética imprescindível na formação estético-literária da criança pré-leitora, que, no processo hermenêutico de apropriação e construção de sentidos, sozinha ou pela mão do adulto-mediador, se assume como um ser cognoscente e cocriador do universo textual, encetando um percurso enunciativo de intensa cooperação interpretativa. Pretende-se igualmente problematizar o lugar dos livros no jardim de infância e o seu contributo para o desenvolvimento cognitivo, social e emocional da criança em idade pré-escolar, atribuindo pedagogicamente ao adulto-mediador um papel determinante nesse processo de construção do ser em crescimento nomeadamente através do recurso ao livro de qualidade estética e literária.

A expressão da depressão e da psicose no desenho infantil na fase da latência

Dissertação de Mestrado apresentada ao Instituto Superior de Psicologia Aplicada para obtenção de grau de Mestre na especialidade de Psicologia Clínica.

Determinação de mercúrio total no material particulado atmosférico do Distrito Federal, Brasil

Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Tecnologia Química e Biológica, 2016.