Uma revisão sobre a resina uréia-formadeído (RUF) empregada na produção de painéis de madeira reconstituída

According to ABIPA (2009), Brazil is currently among the major producers of reconstituted wood panels, with one of the main factors for this condition, its climate and its large land area, which allows the cultivation of forests, which provide raw materials for these industries. To establish that market as power, Brazil has invested about R$ 1.3 billion in the last 10 years, yet designed an investment of 0.8 billion dollars over the next three years (BNDES, 2008). With the new investments in this segment, we expect a growth of about 66% in the resin consumption of urea-formaldehyde (GPC, 2009) which should also result in major investments by the companies producing this polymer. Currently employees are mainly three types of resins in the production industry panels, as follows: Urea-Formaldehyde Resin (R-UF), melamine-formaldehyde resin (R-MF) and Phenol-Formaldehyde Resin (R-FF). Especially the cost factor, the urea-formaldehyde resin is the most used by companies producing reconstituted wood panels. The UF-R is a polymer obtained by condensation of urea and formaldehyde reactors (usually batch type), characterized by being a thermosetting polymer which makes it very efficient for bonding wood composites. The urea-formaldehyde polymer, to present a quite complex, it becomes very difficult to predict the exact chain resulting in the process of condensation of urea with formaldehyde, so that a greater knowledge of its characteristics and methods for their characterization can result in greater control in industrial processes and subsequent decrease cost and improve the quality of reconstituted wood panels produced in Brazil

Infiltração coronária microbiana em canais radiculares obturados pela técnica do cone único com diferentes cimentos endodônticos

With the emergence of new filling materials with different properties and behaviors, the approach of endodontic treatment must be readjusted so that the appropriate result can be achieved. New endodontic sealers include methacrylate resin-based, plant resin-based and the evolution of epoxy-based sealers. This study verified the behavior of new materials that presents controversial results in the literature, about coronal bacterial leakage. That for, 56 single-rooted human teeth were prepared in the direction crown-apex and filled with gutta-percha points with taper of 4% using the single cone technique. Roots were divided randomly into 4 groups according to the sealer (Apexit Plus, AH Plus, EndoREZ and Polifil). After filling, the roots were incorporated in a leakage model, which upper chamber contained a suspension of Streptococcus mutans, and lower chamber a broth, leaving 3 mm of root apical portion immersed. Leakage was assessed for turbidity in lower chamber every day for 60 days. Survival analysis was performed using the nonparametric Kaplan- Meier method (p<0,05). All experimental groups presented leakage during the study’s period, however the maximum time achieve was 22 days. The medium time of leakage was: Apexit Plus 6,3 days, AH Plus 6,3 days and Polifil 5,1 days, but in EndoREZ all specimens infiltrated in the first day, presenting shorter capacity of impermeabilization compared to the other groups. Concluding that none of the sealers tested was able to prevent coronal bacterial leakage

Plano de iluminação externa da UNESP Campus Itapeva com base em LED e energia solar

This work presents the development of the External Lighting Plan UNESP in the Itapeva Campus based LED and Solar Energy. Firstly it was made a collection of data from measurements of the local transit through the Google Earth 6 software and divide the local in sectors, and then perform an analysis of characteristics and age of the site. With these data it was possible to determine the average luminance the place, in30 lux. After these procedures was possible to determine the type of sets that would perform the role of bridge lighting the kit chosen was the 20/20 Sun LED manufacturer, since it contains the luminaire with the solar panel to the pole. Therefore we determined the number of poles for each sector, whichwas72in total and. After the determination of the location of each point lighting

Estudo sobre a tradução de marcadores culturais em três obras de Milton Hatoum com base em corpus paralelo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Educação e Hegemonia: A Formação de Intelectuais na Itália dos Anos 20, a Organização da Industrialização em São Paulo e a Construção da Hegemonia Burguesa no Brasil

The formation of intellectuals, in Gramscian terms (GRAMSCI, 2000), was addressed throughout our academic career, for example, Villela (2003; 2008; 2009; 2010-2012; 2011; 2012; 2014). This article aims to resume some relationships between education of intellectuals in Italy for years 1920, the organization of industrialization in São Paulo and the construction of bourgeois hegemony in Brazil. In this paper I review my dissertation, Villela (2003), whose aim was to understand the rationalization of work processes in architectural offices. This dissertation possible to trace, among other things, another story of the relationship between architecture and state in Brazil from industrialization in São Paulo. Based on the notion of intellectuals Gramsci, we discuss the extended state design and envision a particular kind of state, which in our case is the State industrialist. And relate interested in public policy of that State for industrialization industries office designed by Rino Levi Architects Associate SC Ltda. (ERLAA) that has developed over the decades its activities from 1920 to 1990, many projects in the city of São Paulo. The relationship proposed here is unprecedented. Grounded in this relationship, put in another scene about the formation of intellectuals and hegemony, a Gramscian point of view.

Análise da frequência de micronúcleos frente á utilização de colutório bucal com base alcoólica em indivíduos fumantes e não fumantes

Micronuclei (MN) originate from chromosome fragments or whole chromosomes that lag behind at anaphase during cell division can occur due to excessive exposure to harmful agents, defects in mitosis and / or DNA repair process. The study evaluated the frequency of micronuclei in cytological samples after daily use of alcohol -based mouthwash mouth in smokers and non-smokers. We assessed 30 subjects, aged between 17-42 years and established as exclusion criteria: alcohol consumption; periodontal disease; systemic diseases that may interfere with the integrity of the oral mucosa; individuals with medical or pharmacological history that affect the performance of the study, family history of malignancies. For smokers the inclusion criterion was a minimum consumption of 20 cigarettes / day, and the contrast required for non-smokers. The sample was divided into 02 experimental groups: Group 1 Smokers and Group 2 Non-Smokers, both groups performed mouthwash (alcohol 21,6%) with Listerine® Defense of Teeth and Gums for 04 weeks cytological collection were performed on buccal mucosa and portion median border of the tongue, one for initial, week 0 control, and subsequent three weeks with continued use of mouthwash. The collected material was stained by specific staining Feulgen / Fast Green. The analysis of 3000 cells / individual was performed by light microscopy statistics used Kruskal- Wallis and Mann-Whitney tests for frequency MN. The frequency of micronuclei in buccal mucosa was 1.6 ± 1.75 and 1.46 ± 2.06 for the site language to Group 1 Smokers of showing a slight increase compared with Group 2 Non-smoking, which showed a variation of 1.2 ± 1.53 for the buccal mucosa site and 0.86 ± 1.41 for the site language. However, this difference was not statistically significant. The results suggest that alcohol-based mouthwash tested is not an inducer of genotoxic changes, thus not changing the frequency...

Efeito de protocolos de cimentação na carga de fratura para uma cerâmica de dissilicato de lítio

Pós-graduação em Odontologia Restauradora - ICT

Influência de três tratamentos de superfície para cerâmicas a base de zircônia na resistência adesiva e no comportamento à fadiga do material

Pós-graduação em Odontologia Restauradora - ICT

Análise do crescimento das empresas de base tecnológica no Brasil

Technology-Based Firms (TBFs) are companies with intensive innovation dynamics based on technical competences, and for which high growth rates are expected. Nevertheless, even in developed countries, the evidence suggests that significantly high growth rates are more the exception than the rule. In Brazil, most studies on TBFs focus on factors that limit their success, such as managerial experience and capital availability. Based on extensive field research and on a reliable enterprise growth rate indicator, this article aims to evaluate the expansion of those firms, analyzing its relation to key elements such as degree of consolidation, market insertion, and public policy support. We found a growth rate which, although widely varied amongst firms, was significant and was not directly related to the amount of public policy support.

Desgaste e rugosidade superficial de um cimento de ionômero de vidro nanoparticulado

To compare the abrasion wear resistance and superficial roughness of different glass ionomer cements used as restorative materials, focusing on a new nanoparticulate material. Material and Method: Three glass ionomer cements were evaluated: Ketac Molar, Ketac N100 and Vitremer (3M ESPE, St. Paul, MN, USA), as well as the Filtek Z350 (3M ESPE, St. Paul, MN, USA). For each material were fabricated circular specimens (n=12), respecting the handling mode specified by the manufacturer, which were polished with sandpaper disks of decreasing grit. The wear was determined by the amount of mass (M) lost after brushing (10,000 cycles) and the roughness (Ra) using a surface roughness tester. The difference between the Minitial and Mfinal (ΔM) as well as beroughness of aesthetic restorative materials: an in vitro comparison. SADJ. 2001; 56(7): 316-20. 11. Yip HK, Peng D, Smales RJ. Effects of APF gel on the physical structure of compomers and glass ionomer cements. Oper. Dent. 2001; 26(3): 231-8. 12. Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on the surface characteristics and color of denture resins. J Prosthet Dent 1997; 77(2): 197-204. 13. International organization for standardization. Technical specification 14569-1. Dental Materials – guidance on testing of wear resistance – PART I: wear by tooth brushing. Switzerland: ISO; 1999. 14. Bollen CML, Lambrechts P, Quirynen M. Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater.1997; 13(4): 258-9. 15. Kielbassa AM, Gillmann C, Zantner H, Meyer-Lueckel H, Hellwig E, Schulte-Mönting J. Profilometric and microradiographic studies on the effects of toothpaste and acidic gel abrasivity on sound and demineralized bovine dental enamel. Caries Res. 2005; 39(5): 380-6. 16. Tanoue N, Matsumara H, Atsuta M. Wear and surface roughness of current prosthetic composites after toothbrush/dentifrice abrasion. J Prosthet Dent. 2000; 84(1): 93-7. 17. Heath JR, Wilson HJ. Abrasion of restorative materials by toothpaste. J Oral Rehabil. 1976; 3(2): 121-38. 18. Frazier KB, Rueggeberg FA, Mettenburg DJ. Comparasion of wearresistance of class V restorative materials. J Esthet Dent. 1998; 10(6): 309-14. 19. Momoi Y, Hirosakil K, Kohmol A, McCabe JF. In vitro toothebrushdentifrrice abrasion of resin-modified glass ionomers. Dent Mater. 1997; 13(2): 82-8. 20. Turssi CP, Magalhães CS, Serra MC, Rodrigues Jr.AL. Surface roughness assessment of resin-based materials during brushing preceded by pHcycling simulations. Oper Dent. 2001; 26(6): 576-84. 21. Wang L, Cefaly DF, Dos Santos JL, Dos Santos JR, Lauris JR, Mondelli RF, et al. In vitro interactions between lactic acid solution and art glassionomer cements. J Appl Oral Sci. 2009; 17(4): 274-9. 22. Carvalho FG, Fucio SB, Paula AB, Correr GM, Sinhoreti MA, PuppinRontani RM. Child toothbrush abrasion effect on ionomeric materials. J Dent Child (Chic). 2008; 75(2): 112-6. 23. Coutinho E, Cardoso MV, De Munck J, Neves AA, Van Landuyt KL, Poitevin A, et al. Bonding effectiveness and interfacial characterization of a nano-filled resin-modified glass-ionomer. Dent Mater. 2009; 25(11): 1347-57. tween Rainitial and Rafinal (ΔRa) were also used for statistical analysis (α=0.05). Results: Except for the composite, significant loss of mass was observed for all glass ionomer cements and the ΔM was comparable for all of them. Significant increase in roughness was observed only for Vitremer and Ketac N100. At the end of the brushing cycle, just Vitremer presented surface roughness greater than the composite resin. Conclusion: All glass ionomer cements showed significant weight loss after 10,000 cycles of brushing. However, only Vitremer showed an increase of roughness greater than the Z350 resin, while the nanoparticulate cement Ketac N100 showed a smooth surface comparable to the composite.

Effect of time between adhesive application and photoactivation on adhesion and collagen exposure

Fundacao de Amparo a Pesquisa do Estado de sao Paulo (FAPESP)

Air abrasion before and/or after zirconia sintering: surface characterization, flexural strength, and resin cement bond strength

The purpose of this in vitro study was to evaluate the effect of air-abrasion/zirconia sintering order on the yttria partially stabilized tetragonal zirconia polycrystal (Y-TZP) surface characterization (roughness, morphology, and phase transformation), flexural strength (FS), and shear bond strength (SBS) to a resin cement. Y-TZP specimens were air abraded with 50-μm Al2O3 particles after (AS), before (BS), or before and after zirconia sintering (BAS). For roughness (Ra), 30 block specimens (12×12×3.0 mm; n=10) had their surfaces analyzed by a profilometer. Next, on the air-abraded surfaces of these specimens, composite resin discs (n=30) were bonded with RelyX ARC. The bonded specimens were stored for 24 hours in distilled water at 37°C before shear testing. Failure mode was determined with a stereomicroscope (20×). The surface morphology (n=2) was evaluated by SEM (500×). For the four-point flexural strength test (EMIC DL2000), 39 bar-shaped specimens (20×4.0×1.2 mm; n=13) were air abraded according to the three conditions proposed, and an additional group (nonabraded) was evaluated (n=13). The quantitative analysis of phase transformation (n=1) was completed with Rietveld refinement with X-ray diffraction data. Ra (μm) and SBS (MPa) data were analyzed by one-way analysis of variance (ANOVA) and the Tukey test (α=0.05). Pearson correlation analysis was used to determine if there was a correlation between roughness and SBS. For FS (MPa) data, one-way ANOVA and the Dunnett C-test (α=0.05) were used. The air-abrasion/zirconia sintering order influenced significantly (p<0.001) Ra, SBS, and FS. The BS and AS groups presented the highest (1.3 μm) and the lowest (0.7 μm) Ra. The highest SBS (7.0 MPa) was exhibited by the BAS group, followed by the AS group (5.4 MPa) and finally by the BS group (2.6 MPa). All groups presented 100% adhesive failure. A weak correlation (r=−0.45, p<0.05) was found between roughness and SBS. The air-abrasion/zirconia sintering order provided differences in the surface morphology. The nonabraded (926.8 MPa) and BS (816.3 MPa) groups exhibited statistically similar FS values but lower values than the AS (1249.1 MPa) and BAS (1181.4 MPa) groups, with no significant difference between them. The nonabraded, AS, BS, and BAS groups exhibited, respectively, percentages of monoclinic phase of 0.0 wt%, 12.2 wt%, 0.0 wt%, and 8.6 wt%. The rougher surface provided by the air-abrasion before zirconia sintering may have impaired the bonding with the resin cement. The morphological patterns were consistent with the surface roughness. Considering the short-term SBS and FS, the BAS group exhibited the best performance. Air abrasion, regardless of its performance order, provides tetragonal to monoclinic transformation, while sintering tends to zero the monoclinic phase content.

Masticatory performance of complete denture wearers after using two adhesives: a crossover randomized clinical trial

Statement of problem Masticatory performance analysis of conventional complete denture wearers who use denture adhesives is scarce in the dental literature. Purpose The purpose of this study was to assess the effect of the use of 2 denture adhesives on the masticatory performance of conventional complete denture wearers by means of a crossover study. Material and methods Forty individuals who were edentulous received new maxillary and mandibular complete dentures, and, after an adaptation period, were submitted to masticatory performance analysis without denture adhesive (control). The participants were randomly divided and assigned to 2 protocols: protocol 1, denture adhesive 1 (Ultra Corega cream tasteless) use during the first 15 days, followed by no use of denture adhesive over the next 15 days (washout), and then use of denture adhesive 2 (Ultra Corega powder tasteless) for 15 days; protocol 2, denture adhesive 2 (Ultra Corega powder tasteless) use during the first 15 days, followed by no use of denture adhesive during the next 15 days (washout), and then use of denture adhesive 1 (Ultra Corega cream tasteless) for 15 days. The masticatory performance was assessed immediately after the use of denture adhesive by means of the sieve method, in which participants were instructed to deliberately chew 5 almonds for 20 chewing strokes. Masticatory performance was calculated by the weight of comminuted material that passed through the sieves. Data were analyzed by a 1-way ANOVA for paired samples and the multiple comparison of means by using the Bonferroni test (α=.05). Results A significant increase in masticatory performance was noted after using the Ultra Corega cream (mean, 32.6%) and Ultra Corega powder (mean, 31.2%) when compared with the control group (mean, 19.8%) (P<.001). No significant difference was found between the 2 denture adhesives evaluated. Conclusion The use of denture adhesive improved the masticatory performance of conventional complete denture wearers. No difference was found in masticatory performance with the use of cream or powder denture adhesive.

Effect of different light-curing techniques on hardness of a microhybrid dental composite resin

Coordenação de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)