Percepção de pais e professores sobre crianças e adolescentes com transtorno de déficit de atenção e hiperatividade / Perception of parents and teachers about children and adolescents with attention deficit disorder with hyperactivity

O Transtorno de Déficit de Atenção e Hiperatividade (TDAH) é um dos temas mais estudados em crianças em idade escolar. Sendo basicamente neurológico, o TDAH é caracterizado pela desatenção, agitação (hiperatividade) e impulsividade.O objetivo deste estudo foi analisar a percepção dos pais e professores frente ao TDAH. Trata-se de um estudo transversal, de campo, com abordagem quantitativa e qualitativa.A pesquisa foi desenvolvido com dez pais ou responsável legal de crianças e adolescentes com diagnóstico de TDAH e dez professores da rede de ensino que lesionam para o grupo de crianças e adolescentes com o referido transtorno. Os resultados do estudo indicam a existencia de barreiras para a compreensão do TDAH tanto no ambiente familiar quanto escolar. Abordar os limites no entendimeno do TDAH e fortalecer o elo, nucleo familiar, educacional e de saúde pode permitir não apenas a redução dos sintomas mas o aumento de competências individuais na infância e na adolescência.Reconhecer a percepção dos pais e professores, permite delinear estratégias multidisciplinares e multisetoriais, de modo a ampliar a sua atuação no processo de reabilitação. O estudo permite ainda ampliar co-participação da enfermagem e dos demais profissionais de saúde, na atenção integral e humanizado a saúde do indivíduo, família e comunidade.

Preparação e caracterização de filmes finos de 'BA''BI IND.2''TA IND.2''O IND.9(BBT)' e 'BA''BI IND.2''NB IND.2''O IND.9(BBN)'

Nos últimos anos, filmes finos dos óxidos ferroelétricos de camadas de bismuto, também conhecidos como compostos pertencentes à família do Aurivillius, têm sido extensivamente estudados para aplicações em memórias ferroelétricas de acesso aleatório (FERAM). No entanto, muito pouco se sabe a respeito da preparação e propriedades dielétricas de filmes de BaBi2Ta2O9 (BBT) e BaBi2Nb2O9 (BBN), bem como a respeito da estrutura do BBT. Por isso, numa primeira etapa deste trabalho, pós de BBT foram preparados pelo método Pechini, para a determinação da estrutura. A formação de fases foi acompanhada por DRX. O pó calcinado a 800 oC por 2 horas e sinterizado a 850 oC por 4 horas apresentou 100% da fase BBT. A estrutura do BBT foi determinada pelo Método de Rietveld. Verificou-se que o BBT tem estrutura tetragonal com grupo espacial I4/mm, os cátions Ba e Bi compartilham ambos os sítios 2b e 4e. A fórmula (Ba0,70Bi0,30)(Bi1,64Ba0,36)Ta2O9 pode ser usada para escrever sua fórmula unitária. Numa segunda etapa, filmes finos de BBT e BBN foram preparados pelo método químico de Pechini. As soluções foram depositadas por “spin-coanting” em substratos de Pt/TiO2/SiO2/Si e rotacionados a 3000 rpm durante 30 segundos. Após a deposição os filmes foram tratados termicamente entre 600 e 800 oC sob atmosfera de oxigênio. Os filmes foram analisados por DRX, MEV, MFA, MET e propriedades elétricas. Os filmes preparados por este processamento apresentaram microestrutura heterogênea e piores propriedades dielétricas. Visando controlar a microestrutura e obter melhores propriedades dielétricas, foram feitas algumas modificações no processamento, tais como, adição de excesso de bismuto e adição de uma camada intermediária de tungstênio entre as camadas dos filmes de BBT ou BBN. Tanto a adição de excesso de bismuto como a utilização do dopante tungstênio...In recent years the layered-structure perovskites, also known as Aurivillius compounds have attracted considerable attention for use in ferroelectric random access memories (FeRAM). However, there is little information available about the preparation and dielectric properties of BaBi2Ta2O9 (BBT) and BaBi2Nb2O9 (BBN) thin films, as well as, about the structure of BBT. Therefore, firstly BBT powders were prepared by Pechini method and the phase formation was verified by XRD. The powder calcined at 800 oC / 2 hours and sintered at 850 oC / 4h showed 100% of BBT phase. The structure of BBT was determined by the Rietveld method. BBT shows tetragonal structure (I4/mmm), and Ba and Bi share both the 2b and 4e sites. The (Ba0,70Bi0,30)(Bi1,64Ba0,36)Ta2O9 can be used to describe its unit formula. Secondly, thin films of BBT and BBN were prepared by Pechini method. They were deposited by spin coating over Pt/TiO2/SiO2/Si substrates followed by annealing under oxygen flux at different temperature. The thin films were analyzed by XRD, SEM, AFM, TEM and electric properties. The thin films showed heterogeneous microstructure and worst dielectric properties. Aiming to control the microstructure, it was done some modification during the process of preparation of BBT and BBN thin films. The use of Bi excess as well as the use of W6+ as dopant was favorable to control the microstructure and to obtain better dielectric properties. The best values to dielectric constant and dissipation factor were obtained for BBT thin films with addition of 5 wt% Bi excess heat annealed at 750 oC for 1 hour and BBN thin films with addition of 2 wt% Bi excess heat annealed at 700 oC for 1 hour The typical measured small signal dielectric constant and dissipation factor at 100 kHz were 210 and 0,025 for BBT and 356 and 0,023 for BBN, respectively...(Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Obtenção de niobato de chumbo e zinco (PZN) com fase e microestrutura controladas

O método de Pechini bem como o uso da adição simultânea de partículas sementes (BaTiO3 ou PbTiO3) e de solução dopante contendo íons Ba2+ e Ti4+ ou Pb2+ e Ti4+ foram usados para preparar o niobato de zinco e chumbo (PZN). Com a finalidade de se estudar a influência do tamanho das partículas sementes na obtenção da fase PZN perovskita estável e na microestrutura da cerâmica, trabalhou-se com dois intervalos de tamanhos das partículas sementes: 1- entre 40 nm < φ < 100 nm, denominadas sementes de menor tamanho (frequência de 1015 partículas por cm3); 2- entre 100 nm< φ < 900 nm, denominadas sementes de maior tamanho (frequência de 1013 partículas por cm3). Os difratogramas de raios X obtidos para as amostras calcinadas a 800 oC ou a 900 oC permitiram identificar a formação das fases perovskita e pirocloro, sendo que a 900 oC predomina a fase perovskita. As amostras preparadas com as sementes de maior tamanho, menor frequência de núcleos cristalinos, apresentaram maior porcentagem de fase pirocloro que as preparadas com as sementes de menor tamanho após a calcinação. Os pós foram compactados isostaticamente e sinterizados entre 950 a 1100 oC. Para a sinterização utilizou-se um sistema fechado contendo atmosfera de pó de PbZnO3 + 5% PbO para controlar a evaporação do chumbo estequiométrico, durante a sinterização. A forma na qual os aditivos foram adicionados ao polímero (se como íons ou como sementes), assim como a frequência de núcleos cristalinos influeciaram no processo de sinterização e na microestrutura desenvolvida. As amostras preparadas com as sementes de maior tamanho exigiram uma temperatura mais elevada para a sinterização e apresentaram uma microestrutura mais heterogênea que as amostras preparadas com as sementes de menor tamanho. A microestrutura dos compactos obtidos a partir de pós contendo 50% dos aditivos na forma...Pechini method as well as the simultaneous addition of seeds particles (BaTiO3 or PbTiO3) and dopant solutions containing Ba2+ and Ti4+ or Pb2+ and Ti4+ were used to prepare the perovskite phase of lead zinc niobate (PZN). To study the influence of seed particle size in the formation of stable PZN phase and in the ceramic microstructure, two range of seed particle size were considered: a) in the range of 30 to 100 nm, named small seed particles (frequency of 1015 particles/cm3); and b) in the range of 50 to 900 nm, named large seed particles (frequency of 1013 particles/cm3). The perovskite and pyroclore phases were identified for powder calcined at 800 oC and at 900 oC with predominance of perovskite phase for powder calcined at 900 oC. Powders prepared with large seed particles, smaller crystalline nuclei frequency, showed large amount of pyroclore phase after calcining, compared with the powder prepared with small size seeds. Calcined powders were isostaticaly pressed and sintered at temperatures ranging from 900 to 1100 oC. A close system containing powder with PbZnO3 + 5 PbO, to control the lead evaporation from the compacted samples, was used during sintering. Both, the way in which the additives were added to the polymer (seeds or ions) as well as the crystalline nuclei frequency influenced in the sintering process and in the microstructure. Samples prepared with large seeds need higher temperatures for sintering and showed a more heterogeneous microstructure compared with samples prepared with small seed particles. The microstructure of ceramics prepared for powder containing 50% of additives as seed and 50% of additives as ions is more homogeneous. The microstructure of ceramics obtained from powders containing 80% of additives as seeds and 20% as ions showed grains with well-defined crystalline planes. All the sintered samples showed a second phase segregated to the grain boundary...(Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

ZnO nanostructures directly grown on paper and bacterial cellulose substrates without any surface modification layer

In this report, hierarchical ZnO nano- and microstructures were directly grown for the first time on a bacterial cellulose substrate and on two additional different papers by hydrothermal synthesis without any surface modification layer. Compactness and smoothness of the substrates are two important parameters that allow the growth of oriented structures. © 2013 The Royal Society of Chemistry

Reoxidation of graphene oxide: Impact on the structure, chemical composition, morphology and dye adsorption properties

The chemical composition, oxidation degree, and sheet size strongly affect the properties of graphene oxide (GO). Therefore, much effort has been directed to improve the synthesis of GO and control its structure. Herein, we report the reoxidation of GO using milder conditions of a modified Hummers’ method, including shorter reaction times and a reduced proportion of chemicals to obtain the reoxidized GO (Ox-GO). The reoxidation impact was evaluated by studying the materials’ adsorption performance towards methylene blue (MB) and rhodamine B (RB). Compared to GO, Ox-GO presents a similar C/O ratio, increased interlayer spacing, smaller sheets with holes, a higher exfoliation degree, and slight differences in each oxygenated functional group. Our measurements evidence that Ox-GO has an MB adsorption capacity more than 30% higher than GO under different conditions of dye concentration and pH. Moreover, Ox-GO also shows a notable improvement in the RB removal for a high dye concentration, where the removal capacity is almost 40% higher than that of GO. The enhancements in the dyes’ removal are attributed to the increased accessible surface area of Ox-GO, which provides more sites for dyes’ adsorption

Gas sensor properties of zno nanorods grown by chemical bath deposition

The present work shows a study about the growing of ZnO nanorods by chemical bath deposition (CBD) and its application as gas sensor. It was prepared ZnO nanorods and Au decorated ZnO nanorods and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas sensing response measurements. The results obtained by XRD show the growth of ZnO phase. It was possible to observe the formation of uniform dense well-aligned ZnO nanorods. The results obtained also revealed that Ag nanoparticles have decorated the surface of ZnO nanorods successfully. Au nanoparticles with diameter of a few nanometers were distributed over the ZnO surface nanorods. The gas sensing response measurements showed a behavior of n type semiconductor. Furthermore, the Au-functionalized ZnO nanorods gas sensors showed a considerably enhanced response at 250 and 300 °C

Understanding the Formation of the Self-Assembly of Colloidal Copper Nanoparticles by Surfactant: A Molecular Velcro

Self-assembly procedure is employed to synthesize colloidal copper nanoparticles (ccNPs) with cationic surfactant in an environmentally friendly method. Scanning electron microscopy images provide a clear view of the ccNPs formed having an approximate size of 15 nm. The X-ray diffraction reveals that the ccNPs have the two types of copper oxide as well as the metallic copper. The new procedure shows that the cationic surfactant CTAB plays an important role in the understanding and development of self-assembly. There is a strong relationship between the ccNPs formation with the critical micelle concentration of the CTAB which influences both shape and size. The outcomes allowed the development of a molecular model for the ccNPs synthesis showing that the CTAB monomer on the surface has the function of a molecular velcro making the linkage of ccNPs to form an agglomerate with size around 600 nm. Finally, with the emerging new technologies, the synthesis of copper oxide takes a new perspective for their applicability in diverse integrated areas such as the flexible electronics and energy

Interfacial Characterization of Polypyrrole/AuNP Composites towards Electrocatalysis of Ascorbic Acid Oxidation

Polypyrrole (PPy) is an interesting conducting polymer due to its good environmental stability, high conductivity, and biocompatibility. The association between PPy and metallic nanoparticles has been widely studied since it enhances electrochemical properties. In this context, gold ions are reduced to gold nanoparticles (AuNPs) directly on the polymer surface as PPy can be oxidized to an overoxidized state. This work proposes the PPy electrochemical synthesis followed by the direct reduction of gold on its surface in a fast reaction. The modified electrodes were characterized by electronic microscopic and infrared spectroscopy. The effect of reduction time on the electrochemical properties was evaluated by the electrocatalytic properties of the obtained material from the oxidation of ascorbic acid (AA) and electrochemical impedance spectroscopy studies. The presence of AuNPs improved the AA electrocatalysis by reducing oxidation potential and lowering charge transfer resistance. EIS data were fitted using a transmission line model. The results indicated an increase in the electronic transport of the polymeric film in the presence of AuNPs. However, PPy overoxidation occurs when the AuNPs&rsquo; deposition is higher than 30 s. In PPy/AuNPs 15 s, smaller and less agglomerated particles were formed with fewer PPy overoxidized, confirming the observed electrocatalytic behavior

Crystal structure of BaBi2Ta2O9

The crystal structure of the Aurivillius compound Bi2BaTa2O9 prepared via the chemical route was determined by direct methods using EXPO97, and refined using the Rietveld method with conventional X-ray diffraction data. The structure was found to be tetragonal (space group I4/mmm, number 139) and Z = 2, isomorphic of the Bi2BaNb2O9 reported by Blake and co-workers in the literature (1997). Two refinements were performed using the two asymmetry functions of DBWS-9807 (release 20/May/99). The unit cell for each case are: a = 3.932 22(6) Å, c = 25.5053(6) Å (RA) and a = 3.93250(7) Å, c = 25.5069(6) Å (RCF). The differences for atom positions, interatomic distances and angles are in the range of one standard deviation. Final agreements factors are: Rwp = 7.97%, S = 1.84, RBragg = 4.28%(RA), Rwp = 7.98%, S = 1.84, RBragg = 4.30% (RCF). The occupancies of Ba and Bi in site 2b were refined but constrained to have their summation equal to 1.00. The same constraints were applied to the Ba and Bi of the 4e site. The results show that on site 2b there are 70% of Ba and 30% of Bi and on the site 4e there are 82% of Bi and 18% of Ba. The charge equilibrium is maintained for one standard deviation of the site occupancies. © 2000 International Centre for Diffraction Data