Modos e modas da doença e do corpo

O presente artigo busca compreender o processo da Construção Social da Saúde levando-se em consideração que a saúde, no decorrer da historia dos homens, foi sempre considerada um bem e, por isso, mereceu constante preocupação, no sentido de tornar-se geradora de modas, de modos de fazer e de existir, de conflitos, dualidades e controle social. No decorrer desse tempo, modelos de saúde foram sendo criados, interpretados e recriados, quando necessário, provocando igual processo de transformação nas maneiras de sentir, pensar e agir da população usuária dos mais variados recursos de saúde disponíveis, segundo as relações entre o mágico e o necessário , estabelecendo, entre os que serviam e os que eram servidos, uma relação também tão mágica quanto necessária, intermediada pelo corpo, destes sujeitos, depositário do estado de saúde ou de doença. Além do processo de transformação das mentalidades, são ainda levados em consideração os processos de construção, desconstrução e de evolução do imaginário e das representações sociais vivenciados pelos sujeitos e seus corpos. A evolução dos conhecimentos e o avanço científico-tecnológico são enfocados também como fontes modelares e comunicativas no sentido de ditar regras ao corpo que a humanidade porta socialmente neste século.

Structural studies of NaPO3-WO3 glasses by solid state NMR and Raman spectroscopy

Vitreous samples were prepared in the (100 2 x) NaPO3-x WO3 (0 <= x <= 70) glass forming system using conventional melting-quenching methods. The structural evolution of the vitreous network was monitored as a function of composition by thermal analysis, Raman spectroscopy and high resolution one- and two-dimensional P-31 solid state NMR. Addition of WO3 to the NaPO3 glass melt leads to a pronounced increase in the glass transition temperatures, suggesting a significant increase in network connectivity. At the same time Raman spectra indicate that up to about 30 mol% WO3 the tungsten atoms are linked to some non-bridging oxygen atoms (W-O- or W=O bonded species), suggesting that the network modifier sodium oxide is shared to some extent between both network formers. W-O- W bond formation occurs only at WO3 contents exceeding 30 mol%. P-31 magic angle spinning (MAS)-NMR spectra, supported by two-dimensional J-resolved spectroscopy, allow a clear distinction between species having two, one, and zero P-O-P linkages. The possible formation of some anionic tungsten sites suggested from the Raman data implies an average increase in the degree of polymerization for the phosphorus species, which would result in diminished P-31/Na-23 interactions. This prediction is indeed confirmed by P-31{Na-23} and Na-23{P-31} rotational echo double resonance (REDOR) NMR results, which indicate that successive addition of WO3 to NaPO3 glass significantly diminishes the strength of phosphorus-sodium dipole-dipole couplings.

Study of the effect of the peptide loading and solvent system in SPPS by HRMAS-NMR

The SPPS methodology has continuously been investigated as a valuable model to monitor the solvation properties of polymeric materials. In this connection, the present work applied HRMAS-NMR spectroscopy to examine the dynamics of an aggregating peptide sequence attached to a resin core with varying peptide loading (up to 80%) and solvent system. Low and high substituted BHAR were used for assembling the VQAAIDYING sequence and some of its minor fragments. The HRMAS-NMR results were in agreement with the swelling of each resin, i.e. there was an improved resolution of resonance peaks in the better solvated conditions. Moreover, the peptide loading and the attached peptide sequence also affected the spectra. Strong peptide chain aggregation was observed mainly in highly peptide loaded resins when solvated in CDCl3. Conversely, due to the better swelling of these highly loaded resins in DMSO, improved NMR spectra were acquired in this polar aprotic solvent, thus enabling the detection of relevant sequence-dependent conformational alterations. The more prominent aggregation was displayed by the VQAAIDYING segment and not by any of its intermediary fragments and these findings were also corroborated by EPR studies of these peptide-resins labelled properly with an amino acid-type spin probe. Copyright (c) 2005 European Peptide Society and John Wiley & Sons, Ltd.

Local structure and near-infrared emission features of neodymium-based amine functionalized organic/inorganic hybrids

Nd3+-based organic/inorganic hybrids have potential application in the field of integrated optics. Attractive sol-gel derived di-urea and di-urethane cross-linked poly (oxyethylene) (POE)/siloxane hybrids (di-ureasils and di-urethanesils, respectively) doped with neodymium triflate (Nd(CF3SO3)(3)) were examined by Fourier transform mid-infrared (FT-IR), Raman (FT-Raman), Si-29 magic-angle spinning (MAS) nuclear magnetic resonance (NMR) and photoluminescence spectroscopies, and small-angle X-ray scattering (SAXS). The goals of this work were to determine which cation coordinating site of the host matrix (ether oxygen atoms or carbonyl oxygen atoms) is active in each of the materials analyzed, its influence on the nanostructure of the samples and its relation with the photoluminescence properties. The main conclusion derived from this study is that the hydrogen-bonded associations formed throughout the materials play a major role in the hybrids nanostructure and photoluminescence properties.

Multi-scale structural description of siloxane-PPO hybrid ionic conductors doped by sodium salts

Alkaline metal doped organic - inorganic hybrids have potential applications in the field of portable energy sources. Attractive sol - gel derived urea cross-linked polyether, siloxane - PPO ( poly( propylene oxide)) hybrids doped with sodium salts ( NaClO4 and NaBF4) were examined by multi-spectroscopic approach that includes complex impedance, X-ray powder diffraction (XRPD), small angle X-ray scattering (SAXS), Si-29 and Na-23 magic-angle spinning nuclear magnetic resonance (NMR/MAS), Na K-edge X-ray absorption near edge structure (XANES) and Raman spectroscopies. The goals of this work were to determine which cation coordinating site of the host matrix ( ether oxygen atoms or carbonyl oxygen atoms) is active in each of the materials analyzed, its influence on the nanostructure of the samples and its relation with the thermal and electrical properties. The main conclusion derived from this study is that the NaBF4 salt has a much lower solubility in the hybrid matrix than the NaClO4 salt. Furthermore, the addition of a large amount of salt plays a major role in the hybrid nanostructure and electrical properties, modifying the PPO chain conformation, weakening or breaking the hydrogen bond of the polyether - urea associations and changing the polycondensation and aggregation processes involving the siloxane species.

Glasses in the SbPO4-WO3 system

Glasses in the binary system (100 - x)SbPO4-xWO3 (20 <= x <= 60, x in mol%) have been prepared and characterized. Differential thermal analysis (DTA) shows that the glass transition temperature, T-g increases from 412 degrees C, for samples containing 20 mol% of WO3 to 481 degrees C observed for glass containing 60 mol%. Sample containing 40 mol% in WO3 were observed to be the most stable against devitrification. The structural organization of the glasses has been studied by using Fourier transform infra-red (FTIR), Raman, P-31 Magic angle spinning (MAS) and spin echo nuclear magnetic resonance (NMR) spectroscopies. Results suggest two distinct networks comprising the glass structure, one with high SbPO4 content and the other characteristic of the highest WO3 content samples. The glasses present photochromic properties. Colour changes are observed for samples after exposure to ultraviolet or visible laser light. XANES, at L-1 absorption edge of tungsten, suggests partial reduction from W6+ to W5+ species during the laser irradiation. The photochromic effects and the colour changes, promoted by laser excitation, are reversible and easily removed by heat for during 1 h at 150 degrees C. Subsequent 'write/erase' cycles can be done without degradation of the glasses. (C) 2007 Elsevier B.V. All rights reserved.

Structural studies of NaPO3-MoO3 glasses by solid-state nuclear magnetic resonance and raman spectroscopy

Vitreous samples were prepared in the (100 - x)% NaPO3-x% MoO3 (0 <= x <= 70) glass-forming system by a modified melt method that allowed good optical quality samples to be obtained. The structural evolution of the vitreous network was monitored as a function of composition by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), Raman scattering, and solid-state nuclear magnetic resonance (NMR) for P-31, Na-23, and Mo-95 nuclei. Addition of MoO3 to the NaPO3 glass melt leads to a pronounced increase in the glass transition temperatures up to x = 45, suggesting a significant increase in network connectivity. For this same composition range, vibrational spectra suggest that the Mo6+ ions are bonded to some nonbridging oxygen atoms (Mo-O- or Mo=O bonded species). Mo-O-Mo bond formation occurs only at MoO3 contents exceeding x = 45. P-31 magic-angle spinning (MAS) NMR spectra, supported by two-dimensional J-resolved spectroscopy, allow a clear distinction between species having two, one, and zero P-O-P linkages. These sites are denoted as Q(2Mo)((2)), Q(1Mo)((2)), and Q(0Mo)((2)), respectively. For x < 0.45, the populations of these sites can be described along the lines of a binary model, according to which each unit of MoO3 converts two Q(nMo)((2)) sites into two Q((n+1)Mo)((2)) sites (n = 0, 1). This structural model is consistent with the presence of tetrahedral Mo(=O)(2)(O-1/2)(2) environments. Indeed, Mo-95 NMR data suggest that the majority of the molybdenum species are four-coordinated. However, the presence of additional six-coordinate molybdenum in the MAS NMR spectra indicates that the structure of these glasses may be more complicated and may additionally involve sharing of network modifier oxide between the network formers phosphorus and molybdenum. This latter hypothesis is further supported by Na-23{P-31} rotational echo double resonance (REDOR) data, which clearly reveal that the magnetic dipole-dipole interactions between P-31 and Na-23 are increasingly diminished with increasing molybdenum content. The partial transfer of modifier from the phosphate to the molybdate network former implies a partial repolymerization of the phosphate species, resulting in the formation of Q(nMo)((3)) species and accounting for the observed increase in the glass transition temperature with increasing MoO3 content that is observed in the composition range 0 <= x <= 45. Glasses with MoO3 contents beyond x = 45 show decreased thermal and crystallization stability. Their structure is characterized by isolated phosphate species [most likely of the P(OMo)(4) type] and molybdenum oxide clusters with a large extent of Mo-O-Mo connectivity.

Characterization of nanosized ZnAl2O4 spinel synthesized by the sol-gel method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Imigração e teorias antropólogicas no Brasil (1910-1920)

Brazil takes pride in its alleged lack of racial discrimination. These idealized racial relations are a construction of enlightened elites. This article analyzes one of the main cultural publications in the country in order to establish how European anthropological theories were interpreted by Brazilian intelectuals. In the reappraisal of the country proposed in the journal, the ethnic question was intensely discussed. A whitening of the population was generally perceived as a sort of magic solution to the contradictions in a multiracial, heterogeneous and rigidly hierarchic society. This natural process might be accelerated by an inflow of European immigration. The many expectations and tensions surrounding immigration were expressed in the construction of categories of desirable and undesirable immigrants. Thereof an ideal white country emerged, far away from the myth of racial democracy, which has not materialized in Brazilian society today.

Study of DNA damage induced by dental bleaching agents in vitro

Dental bleaching is a simple and conservative procedure for aesthetic restoration of vital and non-vital discolored teeth. Nevertheless, a number of studies have demonstrated the risk of tissue damage from the contact of these agents with the oral mucosa. In the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. Chinese hamster ovary (CHO) cells in vitro were exposed to six commercial dental bleaching agents (Clarigel Gold - Dentsply; Whitespeed - Discus Dental; Nite White - Discus Dental; Magic Bleaching - Vigodent; Whiteness HP - FGM and Lase Peroxide - DMC). The results pointed out that all dental bleaching agents tested contributed to DNA damage as depicted by the mean tail moment, being the strongest effect observed with the highest dose of hydrogen peroxide (Whiteness HP and Lase peroxide, at a 35% concentration). On the other hand, Magic Bleaching (Vigodent) induced the lowest level of DNA breakage. Negative and positive controls displayed absence and presence of DNA-damaging, respectively. Taken together, these results suggest that dental bleaching agents may be a factor that increases the level of DNA damage. A higher concentration of hydrogen peroxide produced higher noxious activities in the genome as detected by single cell gel (comet) assay.

Microhardness assessment of different commercial brands of resin composites with different degrees of translucence

Owing to improvements in its mechanical properties and to the availability of shade and translucence resources, resin composite has become one of the most widely used restorative materials in present day Dentistry. The aim of this study was to assess the relation between the surface hardness of seven different commercial brands of resin composites (Charisma, Fill Magic, Master Fill, Natural Look, Opallis, Tetric Ceram, and Z250) and the different degrees of translucence (translucid, enamel and dentin). Vickers microhardness testing revealed significant differences among the groups. Z250 was the commercial brand that showed the best performance in the hardness test. When comparing the three groups assessed within the same brand, only Master Fill and Fill Magic presented statistically significant differences among all of the different translucencies. Natural Look was the only one that showed no significant difference among any of the three groups. Charisma, Opallis, Tetric Ceram and Z250 showed significant differences among some of the tested groups. Based on the results found in this study, it was not possible to establish a relation between translucence and the microhardness of the resin composites assessed. Depending on the material assessed, however, translucence variation did affect the microhardness values of the resin composites.

Microhardness of glass ionomer cements indicated for the ART technique according to surface protection treatment and storage time

The aim of this study was to assess the microhardness of 5 glass ionomer cements (GIC) - Vidrion R (V, SS White), Fuji IX (F, GC Corp.), Magic Glass ART (MG, Vigodent), Maxxion R (MR, FGM) and ChemFlex (CF, Dentsply) - in the presence or absence of a surface protection treatment, and after different storage periods. For each GIC, 36 test specimens were made, divided into 3 groups according to the surface protection treatment applied - no protection, varnish or nail varnish. The specimens were stored in distilled water for 24 h, 7 and 30 days and the microhardness tests were performed at these times. The data obtained were submitted to the ANOVA for repeated measures and Tukey tests (α = 5%). The results revealed that the mean microhardness values of the GICs were, in decreasing order, as follows: F > CF = MR > MG > V; that surface protection was significant for MR, at 24 h, without protection (64.2 ± 3.6a), protected with GIC varnish (59.6 ± 3.4b) and protected with nail varnish (62.7 ± 2.8ab); for F, at 7 days, without protection (97.8 ± 3.7ab), protected with varnish (95.9 ± 3.2b) and protected with nail varnish (100.8 ± 3.4a); and at 30 days, for F, without protection (98.8 ± 2.6b), protected with varnish (103.3 ± 4.4a) and protected with nail varnish (101 ± 4.1ab) and, for V, without protection (46 ± 1.3b), protected with varnish (49.6 ± 1.7ab) and protected with nail varnish (51.1 ± 2.6a). The increase in storage time produced an increase in microhardness. It was concluded that the different GICs, surface protection treatments and storage times could alter the microhardness values.

Effects of five carbamide peroxide bleaching gels on composite resin microhardness.

The purpose of this study was to evaluate the effects of five home bleaching products containing 15-16% carbamide peroxide on the microhardness of microhybrid composite resin Z-250 (3M/Espe). A total of 72 specimens were fabricated in cylindrical acrylic matrices (4 x 2 mm), filled with composite resin and photo-activated for 40 seconds. They were divided in 6 study groups (n = 12), according to the bleaching product: Review (SS White), Magic Bleaching (Vigodent), Opalescence (Ultradent), Whiteness Perfect (FGM), Claridex (Biodinâmica), and a control group (not bleached). Specimens were exposed to 1 cc of bleaching gel for 6 hours daily for 2 weeks. The control group specimens were kept in artificial saliva throughout this time. All the specimens were then analyzed in a microhardness tester. Knoop hardness measurements were performed, and the results were submitted to parametric statistical analysis (analysis of variance and Tukey's test). Mean Knoop values and standard deviation were: baseline, 68.52a (4.28); control, 63.42b (7.16); Whiteness Perfect, 57.57c (1.81); Magic Bleaching, 57.22c (3.84); Opalescence, 57.03cd (4.00); Claridex, 53.64de (3.33); Review 51.45e (2.82). Identical letters mean statistical equality according to Tukey's test at the 5% significance level. The products significantly decreased Z-250 (3M/Espe) microhardness.

Síntese e caracterização de partículas esféricas de poli(álcool vinílico) e poli(acetato vinílico) para utilização em embolização

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pesquisa e desenvovimento de novos materiais microporosos e mesoporosos para uso em ressonância magnética nuclear por imagem como agentes de contraste

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)