Microstructures, mechanical and corrosion properties and biocompatibility of as extruded Mg-Mn-Zn-Nd alloys for biomedical applications

Extruded Mg-1Mn-2Zn-xNd alloys (x=0.5, 1.0, 1.5 mass %) have been developed for their potential use as biomaterials. The extrusion on the alloys was performed at temperature of 623K with an extrusion ratio of 14.7 under an average extrusion speed of 4mm/s. The microstructure, mechanical property, corrosion behavior and biocompatibility of the extruded Mg-Mn-Zn-Nd alloys have been investigated in this study. The microstructure was examined using X-ray diffraction analysis and optical microscopy. The mechanical properties were determined from uniaxial tensile and compressive tests. The corrosion behavior was investigated using electrochemical measurement. The biocompatibility was evaluated using osteoblast-like SaOS2 cells. The experimental results indicate that all extruded Mg-1Mn-2Zn-xNd alloys are composed of both α phase of Mg and a compound of Mg7Zn3 with very fine microstructures, and show good ductility and much higher mechanical strength than that of cast pure Mg and natural bone. The tensile strength and elongation of the extruded alloys increase with an increase in neodymium content. Their compressive strength does not change significantly with an increase in neodymium content. The extruded alloys show good biocompatibility and much higher corrosion resistance than that of cast pure Mg. The extruded Mg-1Mn-2Zn-1.0Nd alloy shows a great potential for biomedical applications due to the combination of enhanced mechanical properties, high corrosion resistance and good biocompatibility.

Análise da dentina de dentes decíduos submetidos ao capeamento pulpar indireto

O objetivo do estudo foi avaliar as características da dentina cariada remanescente de molares decíduos quanto à coloração, consistência e microdureza, após um período médio de 3 anos e 8 meses da realização do capeamento pulpar indireto. O estudo clínico constou de 27 dentes que apresentavam lesões cariosas ativas com expressão radiográfica em metade interna de dentina. Aleatoriamente, foi realizado o capeamento pulpar indireto e utilizado como material capeador o hidróxido de cálcio (HC) e o cimento de ionômero de vidro resinoso modificado (CIVRM). As crianças foram acompanhadas através de exames clínicos e radiográficos, e ao longo de um período médio de 3 anos e 8 meses, observou-se um índice de sucesso de 89% para o grupo do HC e de 93% para o CIVRM, não havendo diferença estatisticamente significante entre os dois grupos (p=0,62). Os dentes considerados como sucesso no estudo clínico foram agrupados em um único grupo (grupo teste), que constou de 13 dentes que sofreram esfoliação natural ou exodontia por motivos ortodônticos. Além disso, foram selecionados 15 molares decíduos hígidos (grupo controle positivo) e 15, portadores de lesões cariosas ativas em metade interna de dentina (grupo controle negativo). As amostras do grupo teste tiveram suas respectivas restaurações removidas, a profundidade medida e a dentina remanescente avaliada por um operador calibrado, seguindo critérios descritivos, quanto à consistência e a coloração. Nos dentes do grupo controle positivo, foram realizados preparos cavitários oclusais em até 4 mm de profundidade, enquanto que, no grupo controle negativo, o mesmo operador do estudo clínico realizou a remoção parcial de tecido cariado in vitro. A partir daí, todos os dentes foram preparados para análise de microdureza, que foi realizada por um examinador calibrado, que empregou o princípio de cegamento. Na análise da consistência, todos os dentes do grupo teste (n=13) apresentaram-se endurecidos, enquanto que 9, apresentaram coloração amarela-clara (8 do CIVRM e 1 do HC) e 4, castanho-escura (1 do CIVRM e 3 do HC). Para o teste de microdureza no grupo teste, obteve-se uma média KHN de 40,81 (±16,28) MPa, enquanto que nos grupos controles positivo e negativo, foram alcançados valores médios de 62,73 (±11,24) MPa e 19,15 (±6,99) MPa, respectivamente. A análise estatística mediante o teste ANOVA indicou que houve diferença significativa entre os 3 grupos. Foi constatada a remineralização da dentina de dentes decíduos em que foi realizada a técnica do capeamento pulpar indireto após um período médio de 3 anos e 8 meses, através de critérios clínico (consistência) e laboratorial (análise da microdureza).

Influência do teor de calcário no comportamento físico, mecânico e microestrutural de cerâmicas estruturais

There are ores of clay in Piauí State that are used for red structural ceramics, which are naturally contaminated with calcareous vein. This is one thing that impedes its exploration in an adequate way, especially for tile production. The present work aims at verifying the influence of the calcareous contents in the technological structural ceramics area, seeking to determine a maximum permissible calcareous proportion/contents in the ceramic mass using the patterns of the local industry production. For the consecution of this paper, it was characterized the clay and calcareous material by FRX, DRX, TGA and DTA. It was also configurated by extrusion and burnt in the temperatures of 850°C, 900°C, 950°C and 1000°C pieces of the corpus with 0, 5, 10, 15 e 20% of calcareous proportion. After that, it was carried out technological samples of linear retraction, water absortion, apparent porosity, specific apparent mass and mechanic resistance. The results showed the possibility of using calcareous in the ceramic mass and in some cases the technological properties got better

Desevolvimento de nanocompósitos de poli(metacrilato de metila)/argila processados por mistura no estado fundido

Poly(methyl methacrylate)/clay nanocomposites were prepared by melt mixing using a montmorillonite-rich clay (MMT). The clay in natura was treated with acrylic acid to facilitate the dispersion in the polymer matrix. A masterbatch of PMMA/clay was prepared and combined with the pure PMMA and then subjected to extrusion process using singlescrew and twin-screw extruders followed by injection. Nanocomposites were processed with clay contents of 1, 3, 5 and 8 wt.%. The effect of shear processing on the morphology of the nanocomposites was evaluated by XRD, SEM and TEM. Thermal and mechanical properties of the nanocomposites were investigated through TGA, DSC, HDT, VICAT, tensile and impact tests, to evaluate the effect of the addition of clay to the PMMA matrix. Flammability tests were also conducted to investigate the effect of the addition of clay on the flame retardation properties. SEM images of the nanocomposites indicated the presence of clay agglomerates, which resulted in the reduction of properties such as thermal stability, mechanical strength and impact resistance, and increased the rate of burning for materials processed by both extrusion routes

Efeito da adição dos azocorantes DR73 e DB79 nas propriedades do poli(metacrilato de metila)

Currently new polymeric materials have been developed to replace other of traditionally materials classes. The use of dyes allows to expand and to diversify the applications in the polymeric materials development. In this work the behavior and ability of azo dyes Disperse Blue 79 (DB79) and Disperse Red 73 (DR73) on poly(methyl methacrylate) (PMMA) were studied. Two types of mixtures were used in the production of masterbatches: 1) rheometer 2) solution. Processing by extrusion-blow molding of PMMA was carried out in order to evaluate the applications of polymeric films. Thermal analysis were performed by thermogravimetry to evaluate polymer and azo dyes thermal stability. Colorimetric analysis were obtained through monitoring the spectral variations associated with sys/trans/anti azo dyes isomerization process Colorimetric data were treated and evaluated in accordance to the color system RGB and CIEL*ab, by monitoring the color change as function of time. Mechanical properties, characterized by tensile tests, were evaluated and correlated with the presence and content of azo dyes in the samples. Analyses by scanning electronic microscopy (SEM) were performed on the surfaces of samples to check the azo dye dispersion after the mixing process. It was concluded that the production of PMMA/azo dyes is possible and feasible, and the mixtures produced had synergy of properties for use in various applications

Processamento e caracterização de compósitos Poli(METACRILATO DE METILA)/Sílica (PMMA/SiO2)

Currently the search for new materials with properties suitable for specific applications has increased the number of researches that aim to address market needs. The poly (methyl methacrylate) (PMMA) is one of the most important polymers of the family of polyacrylates and polymethacrylates, especially for its unique optical properties and weathering resistance, and exceptional hardness and gloss. The development of polymer composites by the addition of inorganic fillers to the PMMA matrix increases the potential use of this polymer in various fields of application. The most commonly used inorganic fillers are particles of silica (SiO2), modified clays, graphite and carbon nanotubes. The main objective of this work is the development of PMMA/SiO2 composites at different concentrations of SiO2, for new applications as engineering plastics. The composites were produced by extrusion of tubular film, and obtained via solution for application to commercial PMMA plates, and also by injection molding, for improved the abrasion and scratch resistance of PMMA without compromising transparency. The effects of the addition of silica particles in the polymer matrix properties were evaluated by the maximum tensile strength, hardness, abrasion and scratch resistance, in addition to preliminary characterization by torque rheometry and melt flow rate. The results indicated that it is possible to use silica particles in a PMMA matrix, and a higher silica concentration produced an increase of the abrasion and scratch resistance, hardness, and reduced tensile strength

Desenvolvimento de bioblendas poliméricas a partir de gelatina bovina e de tilápia com amido de milho

The natural raw materials acquired special importance beside the mineral raw materials with the need for using alternative sources to oil, because they can be used to produce biopolymers. Gelatin, produced from the denaturation of collagen, and starch, an abundant polysaccharide in various plants, are examples of biopolymers which have several technological applications, especially in films. The objective of this work is to produce polymeric bioblends with gelatin and corn starch using two types of gelatin: commercial bovine gelatin and gelatin produced from mechanically separated flesh of tilapia (Oreochromis niloticus). For the extraction of tilapia gelatin 3 distinct pretreatments, followed by extraction in distilled water under heating were performed. The properties of gelatin extracted were similar to bovine gelatin, and the differences can be explained by the difference in extraction processes and sources. Blends of commercial gelatin and starch were produced in an internal mixer from a Haake torque rheometer, to study the behavior of the gelatin mixture with starch, thus, the same compositions were processed by twin screw extrusion, to define the mixing parameters. Subsequently, the extrusion of blends of tilapia gelatin and corn starch was carried out in the same twin screw extruder. The physico-chemical, rheological and morphological properties of the blends with thermoplastic starch and gelatin were studied. It was found that various properties vary linearly with increasing concentration of the components. The blends produced are immiscible, and among the two gelatins, tilapia gelatin showed a better interfacial adhesion with the corn starch. Regarding the morphology, gelatins formed the dispersed phase in all compositions studied, even in compositions rich in starch. Can be concluded that the procedure for tilapia gelatin extraction is feasible and advantageous, and the increasing in its scale to a reactor of 30 liters is possible, with a satisfactory yield. The bioblends of bovine gelatin/corn starch and tilapia gelatin/corn starch were successfully produced, and the processing conditions were appropriate

Efeito da velocidade de aquecimento nas propriedades de produtos da cerâmica estrutural

Heating rate is one of the main variables that determine a fire cycle. In industrial processes that use high temperatures, greater fire great can reduce the cost of production and increase productivity. The use of faster and more efficient fire cycles has been little investigated by the structural ceramic industry in Brazil. However, one of the possibilities that aims at modernizing the sector is the use of roller kilns and the inclusion of natural gas as fuel. Thus, the purpose of this study is to investigate the effect of heating rate on the technological properties of structural ceramic products. Clay raw materials from the main ceramic industries in the state of Rio Grande do Norte were characterized. Some of the raw materials characterized were formulated to obtain the best physical and mechanical properties. Next, raw materials and formulations were selected to study the influence of heating rate on the final properties of the ceramic materials. The samples were shaped by pressing and extrusion and submitted to rates of 1 °C/min, 10 °C/min and 20 °C/min, with final temperatures of 850 °C, 950 °C and 1050 °C. Discontinuous cycles with rates of 10 °C/min or 15 °C/min up to 600 °C and a rate of 20 °C/min up to final temperature were also investigated. Technological properties were determined for all the samples and microstructural analysis was carried out under a number of fire conditions. Results indicate that faster and more efficient fire cycles than those currently in practice could be used, limiting only some clay doughs to certain fire conditions. The best results were obtained for the samples submitted to slow cycles up to 600 °C and fast fire sinterization up to 950 °C. This paper presents for the first time the use of a fast fire rate for raw materials and clay formulations and seeks to determine ideal dough and processing conditions for using shorter fire times, thus enabling the use of roller kilns and natural gas in structural ceramic industries

Prevalência de oclusopatias e caracteríticas cefalométricas e dentais de escolares cearense da cidade de Fortaleza

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

Efetividade do clareamento dentário com peróxido de carbamida a 10% e avaliação dos efeitos adversos sobre o esmalte dentário

The aim of the present study was to assess the effectiveness and adverse effects on dental enamel caused by nightguard vital bleaching with 10% carbamide peroxide. This was accomplished through the interaction of researchers from different areas such as dentistry, materials engineering and physics. Fifty volunteers took part in the doubleblind randomized controlled clinical trial. They were allocated to an experimental group that used Opalescence PF 10% (OPA) and a control group that used a placebo gel (PLA). Fragments of human dental enamel from the vestibular surface of healthy premolars, extracted for orthodontic reasons, were fixed to the vestibular surface of the first upper molars of the volunteers for in situ observation. Bleaching was performed at night for 21 days. The observation periods included Baseline (BL), T0 (21 days), T30 (30 days after treatment) and T180 (180 days after treatment, only for the OPA group). Tooth color was assessed by comparing it with the Vita® scale and by the degree of satisfaction expressed by the volunteer. We also assessed adverse clinical effects, dental sensitivity and gingival bleeding. The study of adverse effects on enamel was conducted in vivo and in situ, using the DIAGNOdent® laser fluorescence device to detect mineral loss. Scanning electron microscopy (SEM) was used to check for superficial morphological alterations, energy dispersive spectrophotometry (EDS) to semiquantitatively assess chemical composition using the Ca/P ratio, and the x-ray diffraction (XRD) technique to observe alterations in enamel microstructure. The results showed that nightguard vital bleaching with 10% carbamide peroxide was effective in 96% of the cases, versus 8% for the PLA group. Dental sensitivity was present in 36% (9/25) of the cases. There was no significant association between gingival bleeding and the type of gel used (p = 1.00). In vivo laser fluorescence analysis showed no difference in values for the control group, whereas in the OPA group there was a statistically significant difference between baseline values in relation to the subsequent periods (p<0.01), with lower mean values for post-bleaching times. There was a significant difference between the groups for times T0 and T30. Micrographic analysis showed no enamel surface alterations related to the treatment performed. No significant alteration in Ca/P ratio was observed in the OPA group (p = 0.624) or in the PLA group (p = 0.462) for each of the observation periods, nor between the groups studied (p=0.102). The XRD pattern for both groups showed the presence of three-phase Hydroxyapatite according to JCPDS files (9-0432[Ca5(PO4)3(OH)], 18-0303[Ca3(PO4)2.xH2O] and 25-0166[Ca5(PO4)3(OH, Cl, F)]). No other peak associated to other phases was found, independent of the group analyzed, which reveals there was no disappearance, nucleation or phase transformation. Neither was there any alteration in peak pattern location. With the methodology and protocol used in this study, nightguard vital bleaching with 10% carbamide peroxide proved to be an effective and safe procedure for dental enamel

Efetividade do flúor e da escovação e eficácia dos materiais de colagem ionômero de vidro e resina composta na reversão das microporosidades criadas pelo condicionamento ácido no esmalte dentário

The objectives of this clinical study was to evaluate the use of the toothpaste with fluoride and without fluoride and the daily tooth brushing are effective in the reversion of the dental enamel conditioned by acid. Another objective of this clinical study was to evaluate if the positioning of orthodontic accessories with glass ionomer cement helps in the reversion of the dental enamel conditioned by acid, when compared to composed resin. One hundred and twenty teeth were selected with indication of extraction by orthodontic reasons. The 30 volunteers were divided, randomly, in two groups. A group used toothpaste without fluoride and the other with it. The teeth of the sample were shuffled, in each volunteer. The teeth were conditioned by the 37% orthophosphoric acid. One of the conditioned teeth stayed in the mouth and suffered action of the abrasion for the tooth brushing, in another teeth a stainless steel mesh protection was positioned with glass ionomer cement, in another tooth the screen was glued with composed resin, in a fourth tooth (the control) was only conditioned after the extractions, 60 days later. All the teeth were appraised through DIAGNOdent, MEVA and EDS. In the obtained data it was possible to observe that there were not statistic significant differences in any comparison, even in the group that did not have access to the fluoride in the toothpaste as in the other that had. According with the used methodology, it was possible to observe too that there was not statistic significant differences in any comparison, even in the group that had the stainless steel mesh positioned with glass ionomer cement as in the group that the stainless steel mesh was positioned with composed resin. However, it was observed that there was an improvement in the topography of the enamel in all the teeth. The accomplishment of this study was facilitated due to the participation of the researchers' of the health area (dentistry), materials engineer, physics and chemistry. The researchers were originating from the Federal University of Rio Grande do Norte and of the University of Queensland, in Australia. This interdisciplinary group was decisive in the accomplishment of the study. It can be concluded that the enamel tends to return to its initial aspect, even if the patient does not have access to fluoride. That is probably due the action of the abrasion for the tooth brushing and mastication. In spite of it not being significant, it is suggested that the conditioned enamel was more resistant to the abrasion in the group that had access to fluoride. It was also possible to conclude that the fluoride liberated by the glass ionomer was not enough to provide a significant difference in the enamel conditioned by the acid, when compared with the composed resin, even in the group that did not use fluoride in the toothpaste as in the group that used

Efetividade do uso tópico de fluoreto e da escovação no controle de cáries produzidas "in vivo"

The objective of this clinical study was to evaluate the effectiveness of the toothbrushing with and without fluoride and the daily fluoride rinse (NaF 0.05%) on produced white spot, in vivo. This was a clinical study, controlled, randomized and triple blind. Thirty patients were selected for orthodontics reasons from Orthodontics Specialization Course at the Brazilian Dental Association - Section of Rio Grande do Norte. In this study it was used 4 bicuspid upper and lower. They had orthodontic reason for extractions, in 35 days, at least. The sample had one hundred and twenty teeth that received orthodontic bands. The bands were fixed with polycarboxylate cement, and there was a space standardized between bands and one surface of teeth. The four bicuspid of each patients were randomized and nominated as A, B, C and D. These nominations determinated the sequence of the extractions and what was done in each tooth. All the patients had been submitted to the toothbrushing with or without fluoride for 35 days. After this period, the A tooth of each patient was extracted to serve as control. The others teeth (B, C and D) were extracted one by each week. The entire sample was analyzed through the clinical examination and by laser fluorescence (DIAGNOdent®) in three different times: before orthodontic bands, 28 days after fixed and then removed the bands and, the last one, 07 days after one of the three treatments (toothbrushing with or without fluoride, tooth paste with fluoride and mouth rinse with fluoride). At the beginning all groups (A, B, C and D) had the same conditions, no significant difference was found. The same situation was found in a clinical examination. The results of the DIAGNOdent® for the groups that used tooth paste without fluoride, with fluoride and mouth rinse with fluoride, after 28 days, there was no significant difference. Clinically, the white spot was formed in all teeth after 28 days. When it was compared the three treated groups, the group without fluoride in tooth paste had worst result than the others groups. But there was no significant association between the number of active and inactive white spots and the type of treatment that the teeth had received. The demineralization of the enamel surface, under the orthodontic bands, it happened in a few weeks. The exposition of the white spots in oral environmental resulted in an improvement, but it was not enough to return to the values from the base line, either for the toothbrushing and/or the use of fluorite mouth rinse. Mouth rinse and toothpaste with fluoride have showed to reduce the incidence of demineralization in the enamel, but none seems to be superior to another one in an in vivo study

O tratamento ortodôntico em uma perspectiva a longo prazo: avaliação da estabilidade oclusal e do grau de satisfação dos pacientes

This study aimed to evaluate factors associated to orthodontic treatment stability and patient satisfaction in the long-term. A total of 209 patients (88 class I and 121 class II) treated with straight wire fixed appliance were selected at least 5 years post treatment. Six hundred twenty seven dental casts were examined with the PAR Index at pretreatment (T1), end of treatment (T2), and at long-term follow up (T3, mean 8.5 years post treatment). At T3, a Dental Impact on Daily Living questionnaire was used to assess patient satisfaction with the dentition in the long-term. Friedman test and multiple regression analysis were used to evaluate changes among the time points and factors associated with stability and patient satisfaction. Predictive factors used to exam the occlusion were: PAR Index at T1 and T2, age at T1, the amount of time without retainer, length of Hawley retainer wear, length of follow-up, sex, extraction and third molar status. To assess patient satisfaction were considered: changes produced by the orthodontic treatment (PAR T2-T1), post treatment stability (PAR T3), age at the start of treatment (T1), length of treatment (T2-T1), gender, and extraction. Orthodontic treatment produced a significant improvement of 94.2% in the PAR Index (T2-T1), but this change was not associated with the level of satisfaction when the patient was questioned at T3. No significant change was observed between T2 and T3. However, when the sample was divided according to the level of finalization (PAR T2), it was observed that well-finished patients experienced some deterioration (P<.001), whereas the less well-finished ones showed some improvement (P<.05). Even with the deterioration, the well-finished patients still had a better PAR Index at T3 compared to the less well-finished ones (PAR T2- T3). Regression analysis showed that PAR Index at T1 and T2, age at T1, and length of retainer wear had a slight association with occlusal stability (R2 = 0.27). Patient satisfaction was significantly associated only with PAR Index at T3 (r2=0.125, P<.0001). We can conclude that, even thought orthodontic treatment is quite stable, not so well-finished treatments tend to show some improvement and well-finished ones deteriorate some in the long-term. Despite of that, well-finished patients still have better occlusal characteristics. Patient satisfaction is not related to the result of orthodontic treatment; nevertheless, there is a slight association with dentition in the long-term

Changes in physical properties of extruded sour cassava starch and quinoa flour blend snacks

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

Produção de snacks funcionais à base de farinha de soja e polvilho azedo

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