Estudo da imobilização de proteases para a síntese de oligolisinas

Enzymatic synthesis of peptides using proteases has attracted a great deal of attention in recent years. One key challenge in peptide synthesis is to find supports for protease immobilization capable of working in aqueous medium at high performance, producing watersoluble oligopeptides. At present, few reports have been described using this strategy. Therefore, the aim of this thesis was to immobilize proteases applying different methods (Immobilization by covalent bound, entrapment onto polymeric gels of PVA and immobilization on glycidil metacrylate magnetic nanoparticles) in order to produce water-soluble oligopeptides derived from lysine. Three different proteases were used: trypsin, α-chymotrypsin and bromelain. According to immobilization strategies associated to the type of protease employed, trypsin-resin systems showed the best performance in terms of hydrolytic activity and oligopeptides synthesis. Hydrolytic activities of the free and immobilized enzymes were determined spectrophotometrically based on the absorbance change at 660 nm at 25 °C (Casein method). Calculations of oligolysine yield and average degree of polymerization (DPavg) were monitored by 1H-NMR analysis. Trypsin was covalently immobilized onto four different resins (Amberzyme, Eupergit C, Eupergit CM and Grace 192). Maximum yield of bound protein was 92 mg/g, 82 mg/g and 60 mg/g support for each resin respectively. The effectiveness of these systems (Trypsin-resins) was evaluated by hydrolysis of casein and synthesis of water-soluble oligolysine. Most systems were capable of catalyzing oligopeptide synthesis in aqueous medium, albeit at different efficiencies, namely: 40, 37 and 35% for Amberzyme, Eupergit C and Eupergit CM, respectively, in comparison with free enzyme. These systems produced oligomers in only 1 hour with DPavg higher than free enzyme. Among these systems, the Eupergit C-Trypsin system showed greater efficiency than others in terms of hydrolytic activity and thermal stability. However, this did not occur for oligolysine synthesis. Trypsin-Amberzyme proved to be more successful in oligopeptide synthesis, and exhibited excellent reusability, since it retained 90% of its initial hydrolytic and synthetic activity after 7 reuses. Trypsin hydrophobic interactions with Amberzyme support are responsible for protecting against strong enzyme conformational changes in the medium. In addition, the high concentration of oxirane groups on the surface promoted multi-covalent linking and, consequently, prevented the immobilized enzyme from leaching. The aforementioned results suggest that immobilized Trypsin on the supports evaluated can be efficiently used for oligopeptides synthesis in aqueous media

Desenvolvimento de nanocompósito (hidroxiapatita/ poliuretano) pela gelação (gelling) de poli ( álcool vinílico) (PVA) para remoção de metais pesados

Removing microcontaminants from effluents is a challenge today, because of its high cost and low efficiency, especially in the treatment of effluents containing heavy metals. An alternative that has emerged is the use of biodegradable nanocomposites, which exhibit good removal and recovery performances, in addition to its low cost. With this in mind, the present study aimed to develop and characterize a nanocomposite based on hydroxyapatite (HAP), polyurethane (PU) and polyvinyl alcohol (PVA) for removing heavy metals. Thus, the research was conducted in several steps: i)- Physico-chemical and microbiological hospital effluent characterization; ii)- Production of hydroxyapatite by aqueous precipitation technique, and their characterization; iii)- Production of the nanocomposite in which the hydroxyapatite was added to the polyurethane prepolymers and then the polyvinyl alcohol/hydroxyapatite film was produced; iv)- Polyvinyl composite without film PU/HAp was also produced in the proportions of 20 and 40% HAp; v)- The composites was characterized by the techniques of XRD, FTIR, SEM / EDS, BET, Zeta Potential and TGA; vi)- The sisal and coconut fibres were washed and dried for comparative tests of adsorption; vii)- Adsorption tests for evaluating the removal of heavy metals (nickel and cadmium). Initial screening adsorption capacity (HAp; PU/HAp - 20 and 40%; PU / HAp / PVA), kinetic studies of adsorption of Cd (II) by HAp; multifactorial design analysis (factorial design) for identifying the most important variables in the adsorption of Cd (II) by composite PU/HAp. Also comparative analysis of adsorption of Cd and Ni by composite PU/HAp were conducted, as well as comparative tests of adsorption of Cd (coconut fibre) and Ni (sisal fibre). It was possible to verify that the composite PU/HAp 40% showed better effectiveness for the removal of Cd (II) and Ni (II), above 80%, equivalent to the lignocellulosic fibre used and HAp produced. As main conclusion, it can be referred that the composite PU/HAp 40% is an effective adsorvent to wastewater treatment for heavy metal removal, with low cost and high efficiency

Da acusação às professoras pelo aprisionamento do sujeito em um diagnóstico a uma interrogação acerca da posição do analista

This study arises with two questionings: what is the usefulness of a diagnosis in school? And what moves that demand for diagnosis? Such questions were drawn up in answer to a diagnostic demand produced in the context of our internship in Scholar/Educational Psychology. On the perspective of working these issues, we conducted a literature research on diagnosis, with regard to its history, as a review of the psychoanalytic literature about the subject. This venture led us to a new interrogation: what are the elaborations that teachers produce from the child diagnosis, which place her as having special educational needs? The need of deciding the method that would lead us to answer such question, taking as reference the psychoanalytic theory, led us to an incursion to the subject research in psychoanalysis. This tracking points us that, according to Freud, on what comes to psychoanalysis, theory and research go together and that psychoanalysis is not a totalitarian world vision. On Lacan, the research is from the analysand, research that always implies the analyst and its praxis. Such path forced us to position a change to question the positions we occupy, in this experience, guided by an analytical listening. To discuss our position, we started from two cases and submitted them to construction and analysis. As a result, we found out that there is no way to know in advance what will be done from a diagnosis, which will be its uses. Point we used to considerate devastating to a child. So, to us, all children that received a diagnosis would be destined to a tragedy and what the research has shown us is that not always, not all of them. Thus, more than knowing what moves the demand, the important is the subject uses and our position towards it so they can generate a work

Aplicação de géis de goma guar no processo de clarificação de salmouras e águas produzidas

Produced water is considered the main effluent of the oil industry, due to their increased volume in mature fields and its varied composition. The oil and grease content (TOG) is the main parameter for the final disposal of produced water. In this context, it is of great significance to develop an alternative method based on guar gum gel for the treatment of synthetic produced water, and using as the differential a polymer having high hydrophilicity for clarifying waters contaminated with oil. Thus, this study aims to evaluate the efficiency of guar gum gels in the remotion of oil from produced water. Guar gum is a natural polymer that, under specific conditions, forms three-dimensional structures, with important physical and chemical properties. By crosslinking the polymer chains by borate ions in the presence of salts, the effect salting out occurs, reducing the solubility of the polymer gel in water. As a result, there is phase separation with the oil trapped in the collapsed gel. The TOG was quantified from the spectroscopy in the ultraviolet and visible region. The system was proven to be highly efficient in the removal of dispersed oil from water produced synthetically, reaching removal percentages above 90%.

Cloud query manager: uso de web semântica para evitar o problema de aprisionamento em IaaS

Cloud computing can be defined as a distributed computational model by through resources (hardware, storage, development platforms and communication) are shared, as paid services accessible with minimal management effort and interaction. A great benefit of this model is to enable the use of various providers (e.g a multi-cloud architecture) to compose a set of services in order to obtain an optimal configuration for performance and cost. However, the multi-cloud use is precluded by the problem of cloud lock-in. The cloud lock-in is the dependency between an application and a cloud platform. It is commonly addressed by three strategies: (i) use of intermediate layer that stands to consumers of cloud services and the provider, (ii) use of standardized interfaces to access the cloud, or (iii) use of models with open specifications. This paper outlines an approach to evaluate these strategies. This approach was performed and it was found that despite the advances made by these strategies, none of them actually solves the problem of lock-in cloud. In this sense, this work proposes the use of Semantic Web to avoid cloud lock-in, where RDF models are used to specify the features of a cloud, which are managed by SPARQL queries. In this direction, this work: (i) presents an evaluation model that quantifies the problem of cloud lock-in, (ii) evaluates the cloud lock-in from three multi-cloud solutions and three cloud platforms, (iii) proposes using RDF and SPARQL on management of cloud resources, (iv) presents the cloud Query Manager (CQM), an SPARQL server that implements the proposal, and (v) comparing three multi-cloud solutions in relation to CQM on the response time and the effectiveness in the resolution of cloud lock-in.