155 resultados para Glaucoma primário de ângulo aberto
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This work reports the influence of the poly (ethylene terephthalate) textile and films surface modification by plasmas of O2 and mixtures (N2 + O2), on their physical and chemical properties. The plasma surface polymeric modification has been used for many researchs, because it does not affect the environment with toxic agents, the alterations remains only at nanometric layers and this technique shows expressive results. Then, due to its good acceptance, the treatment was carried out in a vacuum chamber. Some parameters remained constant during all treatment, such as: Voltage 470 V; Pressure 1,250 Mbar; Current: 0, 10 A and gas flow: 10 cm3/min, using oxygen plasma alternating the treatment time 10 to 60 min with an increase of 10 min to each subsequent treatment. Also, the samples were treated with a gas mixture (nitrogen + oxygen) which was varied only the gas composition from 0 to 100% leaving the treatment time remaining constant to all treatment (10 min). The plasma treatment was characterized in-situ with Optics Emission Spectroscopy (OES), and the samples was characterized by contact angle, surface tension, Through Capillary tests, Raman spectroscopy, Infrared attenuated total reflection (IR-ATR) and atomic force microscopy, scanning electronic Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The results showed that oxygen treated fabrics presented high wettability, due to the hydrophilic groups incorporation onto the surface formed through spputering of carbon atoms. For the nitrogen atmosphere, there is the a film deposition of amine groups. Treatment with small oxygen concentration in the mixture with nitrogen has a higher spputered species of the samples
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The titanium and titanium alloys are widely used as biomaterial in biomedical device and so research have been developed aiming to improve and/or better to understand interaction biomaterial/biological environment. The process for manufacturing of this titanium implants usually involves a series of thermal and mechanical processes which have consequence on the final product. The heat treatments are usually used to obtain different properties for each application. In order to understand the influence of these treatments on the biological response of the surface, it was done, in this work, different heat treatments in titanium and analyzed their influence on the morphology, adhesion and proliferation of the pre-osteoblastic cells (MC3T3-E1). For such heat-treated titanium disks were characterized by optical microscopy, contact angle, surface energy, roughness, microhardness, X-ray diffraction and scanning through the techniques (BSE, EDS and EBSD). For the analysis of biological response were tested by MTT proliferation, adhesion by crystal violet and β1 integrin expression by flow cytometry. It was found that the presence of a microstructure very orderly, defined by a chemical attack, cells tend to stretch in the same direction of orientation of the material microstructure. When this order does not happen, the most important factor influencing cell proliferation is the residual stress, indicated by the hardness of the material. This way the disks with the highest level state of residual stress also showed increased cell proliferation
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Metal-ceramic interfaces are present in tricone drill bits with hard ceramic inserts for oil well drilling operations. The combination of actions of cutting, crushing and breaking up of rocks results in the degradation of tricone drill bits by wear, total or partial rupture of the drill bit body or the ceramic inserts, thermal shock and corrosion. Also the improper pressfitting of the ceramic inserts on the bit body may cause its total detachment, and promote serious damages to the drill bit. The improvement on the production process of metal-ceramic interfaces can eliminate or minimize some of above-mentioned failures presented in tricone drill bits, optimizing their lifetime and so reducing drilling metric cost. Brazing is a widely established technique to join metal-ceramic materials, and may be an excellent alternative to the common mechanical press fitting process of hard ceramic inserts on the steel bit body for tricone drill bit. Wetting phenomena plays an essential role in the production of metal/ceramic interfaces when a liquid phase is present in the process. In this work, 72Silver-28Copper eutectic based brazing alloys were melted onto zirconia, silicon nitride and tungsten carbide/Co substrates under high vacuum. Contact angle evolution was measured and graphically plotted, and the interfaces produced were analysed by SEM-EDX. The AgCu eutectic alloy did not wet any ceramic substrates, showing high contact angles, and so without chemical interaction between the materials. Better results were found for the systemns containing 3%wt of titanium in the AgCu alloy. The presence os titanium as a solute in the alloy produces wettable cand termodinamically stable compounds, increasing the ceramics wetting beahviour
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In recent decades have seen a sharp growth in the study area of nanoscience and nanotechnology and is included in this area, the study of nanocomposites with self-cleaning properties. Since titanium dioxide (TiO2) has high photocatalytic activity and also antimicrobial, self-cleaning surfaces in your application has been explored. In this study a comparison was made between two synthesis routes to obtain TiO2 nanoparticles by hydrothermal method assisted by microwave. And after analysis of XRD and SEM was considered the best material for use in nanocomposites. It was deposited nanocomposite film of poly (dimethyl siloxane) (PDMS) with 0.5, 1, 1.5 and 2% by weight of nanoparticles of titanium dioxide (TiO2) by the spraying method. The nanocomposite was diluted with hexane and the suspension was deposited onto glass substrate, followed by curing in an oven with forced air circulation. The photocatalytic activity of the nanocomposite impregnated with methylene blue was evaluated by UV- vis spectroscopy from the intensity variation of absorption main peak at 660nm with time of exposure to the UV chamber. Changes in the contact angle and microhardness were analyzed before and after UV aging test. The effect of ultraviolet radiation on the chemical structure of the PDMS matrix was evaluated by spectrophotometry Fourier transform infrared (FTIR).The results indicated that the addition of TiO2 nanoparticles in the coating PDMS gave high photocatalytic activity in the decomposition of methylene blue, an important characteristic for the development of self-cleaning coatings
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Steel is an alloy EUROFER promising for use in nuclear reactors, or in applications where the material is subjected to temperatures up to 550 ° C due to their lower creep resistance under. One way to increase this property, so that the steel work at higher temperatures it is necessary to prevent sliding of its grain boundaries. Factors that influence this slip contours are the morphology of the grains, the angle and speed of the grain boundaries. This speed can be decreased in the presence of a dispersed phase in the material, provided it is fine and homogeneously distributed. In this context, this paper presents the development of a new material metal matrix composite (MMC) which has as starting materials as stainless steel EUROFER 97, and two different kinds of tantalum carbide - TaC, one with average crystallite sizes 13.78 nm synthesized in UFRN and another with 40.66 nm supplied by Aldrich. In order to improve the mechanical properties of metal matrix was added by powder metallurgy, nano-sized particles of the two types of TaC. This paper discusses the effect of dispersion of carbides in the microstructure of sintered parts. Pure steel powders with the addition of 3% TaC UFRN and 3% TaC commercial respectively, were ground in grinding times following: a) 5 hours in the planetary mill for all post b) 8 hours of grinding in the mill Planetary only for steel TaC powders of commercial and c) 24 hours in the conventional ball mill mixing the pure steel milled for 5 hours in the planetary mill with 3% TaC commercial. Each of the resulting particulate samples were cold compacted under a uniaxial pressure of 600MPa, on a cylindrical matrix of 5 mm diameter. Subsequently, the compressed were sintered in a vacuum furnace at temperatures of 1150 to 1250 ° C with an increment of 20 ° C and 10 ° C per minute and maintained at these isotherms for 30, 60 and 120 minutes and cooled to room temperature. The distribution, size and dispersion of steel and composite particles were determined by x-ray diffraction, scanning electron microscopy followed by chemical analysis (EDS). The structures of the sintered bodies were observed by optical microscopy and scanning electron accompanied by EDS beyond the x-ray diffraction. Initial studies sintering the obtained steel EUROFER 97 a positive reply in relation to improvement of the mechanical properties independent of the processing, because it is obtained with sintered microhardness values close to and even greater than 100% of the value obtained for the HV 333.2 pure steel as received in the form of a bar
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A polyester film has a vast application field, due some properties that are inherent of this kind of material such as, good mechanical resistance, chemical resistance to acids and bases and low production cost. However, this material has some limitations as low superficial tension, flat surface, low affinity to dyers, and poor adhesion which impede the use of the same ones for some finality as good wettability. Among the existent techniques to increase the superficial tension, plasma as energy source is the more promising technique, because of their versatility and for not polluting the environment. The plasma surface polymeric modification has been used for many researchers, because it does not affect the environment with toxic agents, the alterations remains only at nanometric layers and this technique shows expressive results. Then, due to its good acceptance, polyester films were treated with oxygen plasma varying the treatment time from 10 to 60 min with an increase of 10 min to each subsequent treatment. Also, the samples were treated with a gas mixture (nitrogen + oxygen) varying the percentage of each gas the mixture from 0 to 100%, the treatment time remaining constant to all treatments (10 min). After plasma treatment the samples were characterized by contact angle, surface tension, Raman spectroscopy, Infrared attenuated total reflection (IR-ATR) and atomic force microscopy, with the aim to study the wettability increase of treated polyester films as its variables. In the (O2/N2) plasma treatment of polyester films can be observed an increase of superficial roughness superior to those treated by O2 plasma. By the other hand, the chemical modification through the implantation of polar groups at the surface is obtained more easily using O2 plasma treatment
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In this study, it has been investigated the influence of silver film deposition onto 100% polyester woven and non-woven, on the survival of Escherichia coli and Staphylococcus aureus in contact with these surfaces. The treatment was performedin a chamber containing the working gas at low pressure (~ 10-2 mbar). Some process parameters such as as voltage: 470 V; pressure: 10-2 mbar; current : 0.40 A and gas flow: 6 and 10 cm3/min were kept constant. For the treatments with purêargon plasma using a flow of 6 and 10 cm3/min, different treatment times were evaluated, such as, 10 , 20, 30, 40, 50 and 60 minutes. Contact angle (sessile drop), measurements were used to determine the surface tension of the treated fabrics and its influence on the bacteria grow as weel as the possibilities of a biofilm formation. The formation of a silver film, as well as the amount of this element was verified byEDX technique. The topography was observed through scanning electron microscopy (SEM) to determine the size of silver grains formed on the surfaces of the fabric and assess homogeneity of treatment. The X-ray diffraction (XRD) was used to analyze the structure of silver film deposition. The woven fabric treatments enabled the formation of silver particulate films with particle size larger than the non-woven fabrics. With respect to bacterial growth, all fabrics were shown to be bactericidal for Staphylococcus aureus (S. aureus), while for the Escherichia coli (E. coli), the best results were found for the non-woven fabric (TNT) treated with a flow of 10 cm3/min to both bacteria
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The oily sludge is a complex mix of hydrocarbons, organic impurities, inorganic and water. One of the major problems currently found in petroleum industry is management (packaging, storage, transport and fate) of waste. The nanomaterials (catalysts) mesoporous and microporous are considered promising for refining and adsorbents process for environment protection. The aim of this work was to study the oily sludge from primary processing (raw and treated) and vacuum residue, with application of thermal analyses technique (pyrolysis), thermal and catalytic pyrolysis with nanomaterials, aiming at production petroleum derived. The sludge and vacuum residue were analyzed using a soxhlet extraction system, elemental analysis, thin layer chromatography, thermogravimetry and pyrolysis coupled in gas chromatography/mass spectrometry (Py GC MS). The catalysts AlMCM-41, AlSBA-15.1 e AlSBA-15.2 were synthesized with molar ratio silicon aluminum of 50 (Si/Al = 50), using tetraethylorthosilicante as source of silicon and pseudobuhemita (AlOOH) as source of aluminum. The analyzes of the catalysts indicate that materials showed hexagonal structure and surface area (783,6 m2/g for AlMCM-41, 600 m2/g for AlSBA-15.1, 377 m2/g for AlSBA-15.2). The extracted oily sludge showed a range 65 to 95% for organic components (oil), 5 to 35% for inorganic components (salts and oxides) and compositions different of derivatives. The AlSBA-15 catalysts showed better performance in analyzes for production petroleum derived, 20% increase in production of kerosene and light gas oil. The energy potential of sludge was high and it can be used as fuel in other cargo processed in refinery
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The people of Ceará state are descended from miscegenation between the Portuguese colonizers and the native population, resulting in a different facial pattern from other populations. It is important that this pattern be thoroughly understood, along with its minimum and maximum values so that they can be assessed and respected, allowing professionals who deal with the craniofacial complex to work more efficiently and scientifically. Aim: To characterize the morphological pattern of individuals from Ceará state, whose father and grandfather are also native from Ceará, in the 10-12 year age group, not submitted to previous orthodontic treatment, in order to determine: 1) the prevalence of occlusal pattern; 2) the prevalence of dental anomalies (DA) and, 3) the skeletal and dental cephalometric characteristics of individuals that present with normal occlusion and harmonious facial pattern. Methodology: A list of 10-12 year-olds was obtained from 515 schools containing 162,713 students (Education Secretariat of Ceará State), from which 234 individuals were examined (107 boys and 157 girls). The assessment criteria adopted were: 1) Angle s Classification System to determine occlusal pattern. The occlusal characteristics were measured through overbite, overjet, crowding and interincisal diastema. 2) DA are anomalies of number, shape, size, eruption and structure and, 3) in the group that presented with normal occlusion, we used cephalometric analysis measures proposed by Downs, Steiner, Tweed, Holdaway, Jacobson and McNamara. Results: 1) 25.8% of the schoolchildren had normal occlusion, 47.5% class I malocclusion, 22.3% class II malocclusion and 4.2% class III malocclusion. No statistically significant difference was found between the age group studied and sex. Thirty percent of the individuals had normal overbite, while 36.7% and 19.7% had increased and reduced overbite, respectively. Normal overjet was found in 33.7% of the individuals, increased overjet in 50% and reduced in 16.3%. Dental crowding was observed in 62.5% of the individuals and the presence of interincisal diastema in 14.8%. 2) The prevalence of DA was 56.1%, 6.8% in the number, 10.8% in shape, 4.1% in size, 34.5% in eruption, 26.4% in structure and 17.4% had more than one DA. No association was found between DA and sex, but DA was significantly associated to malocclusion (p<0.05); 3) there was no association between sex or facial type between the measures of nasal-labial angle, position and effective maxillary length, effective mandibular length and the sagittal relationship between the molars, overjet and overbite, position of upper incisors, lower incisors and between the incisors themselves. There was a difference between sex, on the VERT index and in lower anterior facial height, upper incisor inclination and line-H, between facial types for the occlusal plane angles, mandibular plane, facial axis, lower incisor inclination, mandibular position, upper incisor position, lower anterior facial height, ANB and line-H. It was concluded that: 1) the most prevalent occlusal type was class I malocclusion, with no distinction for sex or age group, and the assessment of occlusal characteristics showed that excessive overbite and overjet were the most predominant findings, along with a high occurrence of tooth crowding; 2) a high prevalence of DA was found, particularly eruption anomalies, not influenced by sex but significantly associated to malocclusion and 3) individuals from Ceará are predominantly brachyfacial, exhibiting a number of similarities inherent to their facial pattern, such as a convex profile, retracted jaw, reduced lower third and protruded lower incisors. This study was multidisciplinary, involving researchers from the areas of epidemiology, radiology and dentistry, thereby meeting the multidisciplinarity requirements of the Postgraduate Program in Health Sciences
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The aim of this work was to perform the extraction and characterization of xylan from corn cobs and prepare xylan-based microcapsules. For that purpose, an alkaline extraction of xylan was carried out followed by the polymer characterization regarding its technological properties, such as angle of repose, Hausner factor, density, compressibility and compactability. Also, a low-cost and rapid analytical procedure to identify xylan by means of infrared spectroscopy was studied. Xylan was characterized as a yellowish fine powder with low density and poor flow properties. After the extraction and characterization of the polymer, xylan-based microcapsules were prepared by means of interfacial crosslinking polymerization and their characterization was performed in order to obtain gastroresistant multiparticulate systems. This work involved the most suitable parameters of the preparation of microcapsules as well as the study of the process, scale-up methodology and biological analysis. Magnetic nanoparticles were used as a model system to be encapsulated by the xylan microcapsules. According to the results, xylan-based microcapsules were shown to be resistant to several conditions found along the gastrointestinal tract and they were able to avoid the early degradation of the magnetic nanoparticles
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Background: Malnutrition, inflammation and comorbidities are frequent in patients with chronic renal failure in hemodialysis (HD), contributing for morbidity and mortality. Aims: To evaluate the correlation between anthropometric, laboratory parameters, bioelectrical impedance (BIA) and inflammatory markers with the morbidity and mortality of patients in HD, as well as the impact of its alterations throughout 12 months. Methods: 143 patients of a dialysis facility in Northeast Brazil were evaluated throughout 18 months. Patients with more than 3 months on dialysis, older than 18 years, without amputation of hands and feet, were included in the study. We performed a clinical (subjective global assessment - SGA), anthropometric (BMI, percent of ideal weight, MAC, MAMC, MAMA, percent of fat mass and TSF), laboratory (albumin, creatinine, lymphocyte count as nutritional markers and CRP, IL-6 and TNF- as inflammatory markers) evaluation and BIA (reactance, phase angle and percent of body cell mass) at the beginning of study and after 3, 6 and 12 months of follow-up. The association between study variables and deaths and hospitalizations in 6 and 12 months was investigated. The variable with significance < 10% in the univariate analysis had been enclosed in a multivariate logistic regression analysis. We also investigated the risk of mortality and hospitalization associated with differences in measurements of the variables at baseline and six months later. Results: Patients were aged 52.2 ± 16.6 years on the average, 58% were male, and mean dialysis vintage was 5.27 ± 5.12 years. The prevalence of malnutrition varied from 7.7-63.6%, according to the nutritional marker. The variables associated with morbidity and mortality in 6 and 12 months had been creatinine ≤ 9.45 mg/dl, phase angle ≤ 4.57 degrees, BMI ≤ 23 kg/m2, age ≤ 64.9 years, reactance ≤ 51.7 ohms; Charlson´s index ≥ 4 and socioeconomic status ≤ 7. During six months of follow up, decrease in albumin was associated with significantly higher mortality risk. Conclusions: This study detected that the best predictors of morbidity and mortality between nutritional and inflammatory markers are phase angle, reactance, creatinine and BMI and that changes in albumin values over six 107 months provide additional prognostic information. The authors believe that parameters of BIA may detect early changes in nutritional status and emphasize that longitudinal studies with larger number of patients are necessary to confirm these data and to recommend BIA as a routine nutritional evaluation in HD patients
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According to the global framework regarding new cases of tuberculosis, Brazil appears at the 18th place. Thus, the Ministry of Health has defined this disease as a priority in the governmental policies. As a consequence, studies concerning treatment and prevention have increased. Fixed-dose combination formulations (FDC) are recognized as beneficial and are recommended by WHO, but they present instability and loss on rifampicin bioavailability. The main purpose of this work was to carry out a pre-formulation study with the schedule 1 tuberculosis treatment drugs: rifampicin, isoniazid, pyrazinamide and ethambutol and pharmaceutical excipients (lactose, cellulose, magnesium stearate and talc), in order to develop an FDC product (150 mg of rifampicin + 75 mg of isoniazid + 400 mg of pyrazinamide + 250 mg of ethambutol). The studies consisted of the determination of particle size and distribution (Ferret s diameter) and shape through optical microscopy, as well as rheological and technological properties (bulk and tapped densities, Hausner Factor, Carr s Index, repose angle and flux rate) and interactions among drugs and drug excipient through thermal analysis (DSC, DTA, TG and your derivate). The results showed that, except isoniazid, the other drugs presented poor rheological properties, determined by the physical characteristics of the particles: small size and rod like particles shape for rifampicin; rectangular shape for pyrazinamide and ethambutol, beyond its low density. The 4 drug mixture also not presented flowability, particularly that one containing drug quantity indicated for the formulation of FDC products. In this mixture, isoniazid, that has the best flowability, was added in a lower concentration. The addition of microcrystalline cellulose, magnesium stearate and talc to the drug mixtures improved flowability properties. In DSC analysis probable interactions among drugs were found, supporting the hypothesis of ethambutol and pyrazinamide catalysis of the rifampicin-isoniazid reaction resulting in 3- formylrifamycin isonicotinyl hydrazone (HYD) as a degradation product. In the mixtures containing lactose Supertab® DSC curves evidenced incompatibility among drugs and excipient. In the DSC curves of mixtures containing cellulose MC101®, magnesium stearate and talc, no alterations were observed comparing to the drug profiles. The TG/DTG of the binary and ternary mixtures curves showed different thermogravimetrics profiles relating that observed to the drug isolated, with the thermal decomposition early supporting the evidences of incompatibilities showed in the DSC and DTA curves
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This study aimed to establish patterns of dynamics of litter and redistribution of rainfall of Caatinga vegetation. Sampling was done monthly for twenty three months in four areas: degraded, successional primary stage, secondary stage and late stage. We installed 72 collectors of 1.0 mx 1.0 m, with nylon fabric background in three areas. Litter deposited was fractionated into leaves, twigs, reproductive structures and miscellaneous, dried and weighed. To assess the stock of accumulated litter we used metal frame with dimensions of 0.5 mx 0.5 m, thrown randomly and collected monthly, taken to the laboratory for oven drying and weighed. To evaluate the decomposition, 40g of litter were placed in nylon bags (litterbags) mesh 1 mm ², dimensions 20.0 x 20.0 cm, being distributed on the soil surface and removed monthly, cleaned, dried and weighed. To evaluate the contribution of rainfall we used interceptometers installed 1.0 m above the ground surface, distributed under the canopy of six species of the caatinga, which evaluated the stemflow through collecting system installed around the stems of these species. The deposition of litter in the primary stage was 2.631,26 kg ha-1; 3.144,89 kg ha-1 in the secondary stage; 3.144,89 kg ha-1 in the late stage. The fraction of leaves was the largest contributor to the formation of litter in three stages. The degraded area showed greater accumulation of litter and decomposition has been sluggish during the dry period. We conclude that occurred greater litterfall in later stages. The late successional stage showed faster decomposition of litter, the evidence that is a better use of litter in nutrient cycling processes and incorporation of organic matter to the soil. The time required to decompose 50 % of the litter in the later stages of succession was lower indicating greater speed of release and reuse of nutrients by the vegetation. The specie jurema preta with less leaf area and consists of leaflets, showed greater internal precipitation in rain events of greater magnitude. The stemflow was not influenced by DAP and basal area. The water lost by trapping represented the largest proportion of total rainfall in all species studied
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Se estudia el Movimiento de las Profesoras Primarias de la Red Estadual de Enseñanza, en Salvador/BA como un movimiento social responsable por la creación de la entidad representativa de la categoría la Sociedade Unificadora de Profesores Primários (SUPP). Se parte del presupuesto de que los intereses en la valorización profesional constituyen factores fundamentales para su eclosión. Se recurre a un referente teórico para sedimentar la investigación empírica realizada a través de las profesoras primarias que participaron del Movimiento; una vez que reúne recuerdos individuales y colectivos. Se abordan las condiciones sociales, políticas, económicas y educativas que viabilizaron el surgimiento de dicho movimiento y se delimita el intervalo temporal entre 1947 al 1951. Se destaca que fueron necesarios hacer recortes históricos, los cuales han antecedido y proseguido a ése período, en función al relieve del contexto histórico-social para la comprensión de lo que fue y dónde se ubicaba el objeto de la investigación. Se identificaron tres marcos: el primero se refiere a las motivaciones en defensa de la valorización profesional, situado en un contexto de reformas educativas y pensamiento democrático; el segundo vinculado a la creación de la entidad representativa, fomentando por la necesidad de creación de una institución representativa que pudiese resguardar la categoría. Por lo tanto, se delinea la construcción histórica del Movimiento de las Profesoras Primarias, utilizando las categorías de docencia y movimiento social, de forma interpretativa. Se articulan a los hechos y acontecimientos que marcaron ése movimiento y su importancia para la Historia de la Educación de Bahia. Aun que la lucha por la valoración salarial haya sido el possibilitador de la creación de la SUPP, se constato que fue una movilización política y social buscó el sentido y el significado de lo que sea docencia con acciones que intentaban la integración del profesorado primario baiano (del interior con los de la capital) y promover el desarrollo cultural aliado a la concientización de la categoría
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior