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O artigo apresenta estudo do benefício assistencial de prestação continuada ao idoso e deficiente no que concerne ao critério de renda legalmente estabelecido para sua concessão. Inicia-se por um breve escorço histórico do instituto, com destaque para as principais alterações jurisprudenciais sobre a matéria, em especial no que concerne à interpretação do §3º do art. 20 da lei 8742/1993 e oscilação referente à classificação como presunção juris et de juri ou juris tantum. Passa-se, então, à análise do IRDR 5013036-79.2017.4.04.0000/ RS, julgado pelo TRF da 4ª Região, que fixa a tese da presunção absoluta de miserabilidade nas hipóteses de enquadramento da renda per capita ao critério estabelecido na Lei Orgânica de Assistência Social.

This paper describes the formation of polymeric films derived from 3-hydroxyphenylacetic acid electropolymerized onto graphite electrodes through cyclic voltammetry. We observed the formation of an electroactive material over the electrode surface. The modified electrode showed significant blocking behavior to electron transfer reaction of the pair redox ferricyanide/ferrocyanide, indicating repulsion electrostatic with the negatively charged carboxylate groups of the polymer. The quasi-reversible behavior to Ru(NH3)6Cl2 suggests electrostatic attraction, facilitating the charge transfer. The modified electrode was studied through electrochemical quartz crystal microbalance, electrochemical impedance spectroscopy, and atomic force microscopy. These analyses indicate modification of the graphite electrode. Surface analysis by AFM showed that the morphology of the modified electrode surface presents globular form, randomly distributed, and formed by lower globules with diameter near 100 nm. Immobilization and hybridization of oligonucleotide onto the modified electrode were successfully carried out by using both direct electrochemical oxidation of nitrogenated bases and the redox electroactive indicator methylene blue.

This work describes the immobilization of purine and pyrimidine bases and immobilization/hybridization of synthetic oligonucleotides on graphite electrodes modified with poly(4-methoxyphenethylamine) produced in acid medium. The immobilization of adenine, guanine, cytosine and thymine on these modified electrodes was efficient, producing characteristic peaks. Another relevant observation is that, according to the literature, pyrimidine bases, cytosine and thymine are more difficult to detect. However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained. The observation of the hybridization between the poly(GA) probe and its complementary, poly(CT) target, was possible by monitoring the guanosine and adenosine peaks or through methylene blue indicator, using differential pulse voltammetry. Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface. The hybridization with the complementary target was also investigated by electrochemical impedance spectroscopy. The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance.

This paper reports the formation of electropolymerized films derived from 3-aminophenol on graphite electrode by cyclic voltammetry, prepared in different pH conditions. With increase of pH values, a shift of the oxidation potential of 3-aminophenol to more cathodic potentials was observed. 3-Aminophenol electrooxidation, in acid and basic media, yielded polymeric films onto graphite surface. In ferrocyanide/ferricyanide solution, the polymer produced in acid medium showed higher electron transfer efficiency. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and FT-IR were used to investigate some properties of the graphite electrode modified with poly(3-aminophenol). Scanning electron microscopy showed that the morphology of the films is strongly dependent on the pH of the electropolymerization medium. FT-IR spectra of polymer films produced for either acid or basic media suggest that the monomer is polymerized by NH 2 group.

Electrodes modified with electropolymerized films have received considerable attention in the development of catalysts and sensors, and their use is rapidly increasing. This work reports modification of the surface of graphite electrodes by electrochemical polymerization of tyramine. These modified electrodes were used to nickel incorporation and hydrogen evolution. Tyramine electrooxidation, in acid and basic media, yielded polymeric films onto graphite surface. In ferrocyanide/ferricyanide solution, the electrodes modified in acid medium showed higher electron transfer efficiency. Impedance studies indicated higher charge transfer resistance to electrodes modified with Ptyr prepared in basic pH. Scanning electron microscopy showed that the formed films present different morphology for the several pH values studied. Interferometry and scanning electron microscopy analysis showed higher coverage to films formed in acid medium. Polymers produced in more alkaline medium present growth self-limited. Nickel was incorporated in the films through immersion of the modified electrodes in solution of potassium hexafluoronickelate, followed of electrochemical reduction of the metal. The electrocatalytic activity of the modified electrodes with nickel incorporated was tested for hydrogen evolution reaction. The amount of nickel mass incorporated as well as the current density of hydrogen evolution reaction was higher in electrodes modified with polytyramine produced in acid medium.

Conducting polymers or semi-conductors have various features that make them excellent materials for the immobilization of biomolecules and the rapid transfer of electrons necessary for the production of biosensors. Conducting electroactive polymers of poly-4-aminophenol have been developed as sensors to detect the purine bases (adenosine triphosphate, ATP and guanosine triphosphate, GTP) of DNA. The electrooxidation of 4-aminophenol onto a graphite electrode in the presence of perchloric acid yielded thin polymer films. The conductivity was studied by cyclic voltammetry and surface morphology by optical microscopy and interferometry. The immobilization and detection of ATP and GTP on a graphite electrode or modified electrode coated with poly-4-aminophenol was studied by cyclic voltammetry. Systematic variation of the experimental conditions that influenced the electrode reaction, particularly the pH of the electrolytic solution, showed that the oxidation potentials of the immobilized ATP or GTP in the modified electrodes decreased with increasing pH of the electrolyte. When these conditions were optimized based on voltammetric measurements, modified electrodes coated with poly-4-aminophenol were found to be efficient in immobilizing purine bases, and increased the amplitude of the ATP and GTP signals by ∼1.5 and ∼24 times, respectively, when compared with non-coated graphite surfaces.

It was observed the formation of polymeric films derived from 4-aminophenol on the graphite electrode in aqueous medium (pH 0.5, 8.0 and 12.0). The electrochemical behavior of formed films was studied by voltammetry cyclic and impedance. These analyses indicate that the preparation in acid medium favors the charge transfer rate of the polymer. Polymers formed at pH 8.0 present higher coverage of the electrode surface and impedance increase. Scanning electron microscopy showed that the formed polymer present globular morphology.