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Search Results: 1 - 10 of 24490 matches for " Igor Lima;Santana "
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Heat treatment of a direct composite resin: influence on flexural strength
Miyazaki, Caroline Lumi;Medeiros, Igor Studart;Santana, Ivone Lima;Matos, Jivaldo do Rosário;Rodrigues Filho, Leonardo Eloy;
Brazilian Oral Research , 2009, DOI: 10.1590/S1806-83242009000300004
Abstract: the purpose of this study was to evaluate the flexural strength of a direct composite, for indirect application, that received heat treatment, with or without investment. one indirect composite was used for comparison. for determination of the heat treatment temperature, thermogravimetric analysis (tga) and differential scanning calorimetry (dsc) were performed, considering the initial weight loss temperature and glass transition temperature (tg). then, after photoactivation (600 mw/cm2 - 40 s), the specimens (10 x 2 x 2 mm) were heat-treated following these conditions: 170oc for 5, 10 or 15 min, embedded or not embedded in investment. flexural strength was assessed as a means to evaluate the influence of different heat treatment periods and investment embedding on mechanical properties. the data were analyzed by anova and tukey's test (α = 0.05). tga showed an initial weight loss temperature of 180oc and dsc showed a tg value of 157°c. heat treatment was conducted in an oven (flli manfredi, italy), after 37°c storage for 48 h. flexural strength was evaluated after 120 h at 37°c storage. the results showed that different periods and investment embedding presented similar statistical values. nevertheless, the direct composite resin with treatments presented higher values (178.7 mpa) compared to the indirect composite resin (146.0 mpa) and the same direct composite submitted to photoactivation only (151.7 mpa). within the limitations of this study, it could be concluded that the heat treatment increased the flexural strength of the direct composite studied, leading to higher mechanical strength compared to the indirect composite.
Tratamento da doen?a hemorroidária com ligadura elástica: estudo prospectivo com 59 pacientes
Motta, Marcel Machado da;Silva Júnior, José Batista da;Santana, Larice Oliveira;Ferdandes, Igor Lima;Moura, Alex Rodrigues;Prudente, Ana Carolina Lisboa;Torres Neto, Juvenal da Rocha;
Revista Brasileira de Coloproctologia , 2011, DOI: 10.1590/S0101-98802011000200005
Abstract: rubber band ligation (rb) is considered a minimally invasive method for the treatment of hemorrhoidal disease (hd) and has advantages in relation to hemorrhoidectomy whereby: simplicity of execution, outpatient realization and no need of anesthesia. it is an effective method, especially in the hd grade ii. however, shows complications, and the most frequents are: anal pain, tenesmus, hematochezia and urinary retention. some studies have shown severe complications as major bleeding that needs blood transfusion. thus, this study evaluated the effectiveness and the morbidity of the treatment of hd by the method of rb. it was a prospective study with 59 patients. five (8,5%) patients had hd graded in the first degree, 33 (55,9%) in the second degree and 21 (35,6%) in the third. all patients were submitted to at least two sessions. in the 135 sessions performed, we found: hematochezia in 62 (45.9%), severe pain in 39 (28.9%), vagal symptoms in 10 (7.4%) and pseudostrangulation in 1 (0.7%) session. the cure rate of hemorrhoidal prolapse among patients with hd grade ii was 87.9% and among those with hd grade iii, 76.2%. the treatment of hd by the method of rb proved to be safe and with good cure rate.
Anus neoplasm: study of a case series
Fernandes, Igor Lima;Santana, Larice Oliveira;Silva Júnior, José Batista Da;Motta, Marcel Machado Da;Moura, Alex Rodrigues;Prudente, Ana Carolina Lisb?a;Torres Neto, Juvenal Da Rocha;
Journal of Coloproctology (Rio de Janeiro) , 2011, DOI: 10.1590/S2237-93632011000300009
Abstract: anus neoplasm accounts for 2 to 4% of colorectal tumors, being more prevalent around the seventh and the eighth decades. females are mostly affected, and the ratio is 3:1. its increased prevalence amongst the population in the past years is probably related to the higher number of people that are affected by sexually transmitted diseases, mainly human papillomavirus (types 16 and 18, mostly) and/or the human immunodeficiency virus. diagnosis is based on clinical findings and anatomopathological tests. the treatment of choice is radiochemotherapy, and the rescue surgery with abdominoperineal resection is used for recurrence and persistence cases. a retrospective and prospective longitudinal observational study was performed with 11 patients diagnosed with anal neoplasm from 2004 to 2010. six (54.5%) were females and five (45.5%) were males. the incidence was higher in the sixth decade, at the mean age of 54.45 years. the most frequent histological type observed was the epidermoid carcinoma, and the most frequent cell differentiation type was the moderately differentiated. chemotharapy associated with radiotherapy was used in 81.9% of the patients, and abdominoperineal resection was necessary as a rescue surgery in 18.2% of the patients.
Combining Geographic Information Systems for Transportation and Mixed Integer Linear Programming in Facility Location-Allocation Problems  [PDF]
Silvia Maria Santana Mapa, Renato da Silva Lima
Journal of Software Engineering and Applications (JSEA) , 2014, DOI: 10.4236/jsea.2014.710076
Abstract: In this study, we aimed to assess the solution quality for location-allocation problems from facilities generated by the software TransCAD® , a Geographic Information System for Transportation (GIS-T). Such facilities were obtained after using two routines together: Facility Location and Transportation Problem, when compared with optimal solutions from exact mathematical models, based on Mixed Integer Linear Programming (MILP), developed externally for the GIS. The models were applied to three simulations: the first one proposes opening factories and customer allocation in the state of Sao Paulo, Brazil; the second involves a wholesaler and a study of location and allocation of distribution centres for retail customers; and the third one involves the location of day-care centers and allocation of demand (0 - 3 years old children). The results showed that when considering facility capacity, the MILP optimising model presents results up to 37% better than the GIS and proposes different locations to open new facilities.
Effects of heat treatment on the microhardness of direct composites at different depths of restoration =Efeito do tratamento térmico na microdureza de resinas compostas diretas em diferentes profundidades de restaura o
Santana, Ivone Lima et al.
Revista Odonto Ciência , 2012,
Abstract: Objetivo: Este estudo procurou verificar se o tratamento térmico influencia na microdureza Knoop (KHN) de resinas compostas, e observar se existem diferen as entre áreas fotoativadas antes e depois da aplica o do calor. Metodologia: Oitenta e quatro amostras retangulares transversais (10×2 mm×2 mm) foram preparadas, 14 por resina composta. Após fotoativa o (600 mW/cm2- 40), sete espécimes por compósito foram tratados termicamente (170oC/10min), enquanto os demais permaneceram sem tratamento térmico (controle). Os dados de KHN foram obtidos em três áreas de cada amostra, de acordo com a distancia a partir da superfície irradiada (mais próxima, intermediária e mais distante). Os dados foram analisados por ANOVA a dois critérios e teste de Tukey a 5%. Resultados: O aumento da KHN foi dependente dos compósitos estudados. Os valores da KHN da TE-Econ mico, Natural Look e Prisma foram significativamente melhorados por tratamento térmico (P<0,05), enquanto que na FillMagic e Glacier permaneceram inalterados (P>0,05) após o aquecimento. A área mais distante irradiada influenciou significativamente a KHN para todos os compósitos, independentemente da aplica o de tratamento térmico (P<0,05). Quanto mais próximo da superfície irradiada, maior foi a KHN observada (P<0,05). Conclus o: A escolha do compósito é importante quando é proposta a melhora da KHN por aquecimento. Quanto mais próximo da fonte de irradia o, maior a dureza mesmo após tratamento térmico. Purpose: The mechanical properties of direct composites may be improved by heat treatment. This study aimed to verify whether heat treatment influences the Knoop microhardness (KHN) of direct composites and whether there are differences among photoactivated areas before and after the application of heat. Methods: A total of 84 rectangular cross-sectional specimens (10×2×2mm) was prepared, 14 per composite. After photoactivation (600mW/cm2-40s), seven specimens per composite were heat-treated (170oC/10 min), whereas the others remained unheated (control). KHN values were obtained for three sites on each specimen at specified distances from the irradiated surface (0. 2, 1. 0, and 2. 0mm). The data were analyzed by two-way ANOVA and Tukey’s test at with a significance level set to 5%. Results: The improvement in the KHN values depended on the composites studied. The KHN values of TE-Economic, Natural Look, and Prisma were significantly improved by heat treatment (P<0. 05), whereas FillMagic and Glacier remained unchanged (P>0. 05) after heating. The distance from the irradiated area significantly influenced the
Thermal behavior of direct resin composites: glass transition temperature and initial degradation analyses = Comportamento térmico de resinas compostas de uso direto: temperatura de transi o vítrea e temperatura de degrada o inicial
Santana, Ivone Lima et al.
Revista Odonto Ciência , 2011,
Abstract: Objetivo: A associa o de resinas compostas de uso direto com tratamentos térmicos pode melhorar as propriedades mecanicas destes materiais. No entanto, a temperatura ideal de aplica o está na dependência do comportamento térmico individual, como a temperatura de transi o vítrea (Tg) e a temperatura inicial de degrada o. Com o objetivo de propor uma metodologia de aplica o do tratamento térmico, o objetivo deste trabalho foi caracterizar cinco resinas compostas de uso direto usando calorimetria exploratória diferencial (DSC) e termogravimetria (TGA). Metodologia: Corpos-de-prova cilíndricos (3×2 mm) foram fotoirradiados utilizando um aparelho de fotopolimeriza o (600 mW/cm2 – 40s). As análises térmicas foram realizadas nas temperaturas de 25 oC a 900 oC. Resultados: Os valores de Tg após análise de DSC foram: 130,6 oC para FillMagic, 129 oC para Glacier, 143,5 oC para Te-Econom, 147,5 oC para Prisma APH e 143,7 oC para Natural Look. Para todos os materiais estudados a degrada o iniciou-se por volta de 270 oC. Conclus o: Considerando a aplica o do tratamento térmico em resinas compostas de uso direto, é possível sugerir que a temperatura efetiva é dependente do material em uso.
Dependência de jogos eletr?nicos: a possibilidade de um novo diagnóstico psiquiátrico
Lemos, Igor Lins;Santana, Suely de Melo;
Revista de Psiquiatria Clínica , 2012, DOI: 10.1590/S0101-60832012000100006
Abstract: background: the practice of electronic games has been disconnected from a merely playful character, as its excessive use may be considered as a new psychiatric disorder. objective: to accomplish a review of the scientific literature concerning this possible dependence, addressing its main characteristics, worldwide prevalence and the possibility of comorbidities, and to evaluate the existence of treatment procedures based on cognitive behavioral therapy. method: the research was conducted for articles published between 2001 and june 2011, using the pubmed, bvs, lilacs and scielo databases. results: there is no consensus whether the electronic game dependence is affiliated with the impulse control disorder group or chemical dependence. but it is known that the worldwide prevalence of this dependence has an average of 3%, with male predominance, and that there exist comorbidities of electronic game and chemical dependence. the cognitive behavioral therapy is already used as a possible treatment with effective short-term results. discussion: despite dependence on electronic games is not considered as a specific diagnosis, this new phenomenon should be discussed and deepened in the scientific literature, seeking, in parallel, an efficient model of psychotherapeutic and pharmacological treatment.
Capitalismo, cidade e política na perspectiva de David Harvey
Marco Aurélio Santana,Igor Peres
Sociologia & Antropologia , 2013,
Abstract: O texto discute alguns eixos conceituais relevantes para a compreens o da obra de David Harvey, concentrando-se especificamente nas formula es do autor acerca da ideia de rearranjo espacial (spatial fix), de novo imperialismo (new imperialism) e de acumula o mediante despossess o (acumulation by dispossession). Objetiva-se lidar também com o que se seriam os componentes da teoria critica de Harvey. Além disso, apresenta-se como tais ideias e formula es n o podem ser plenamente entendidas sem o seu enraizamento nas reflex es do autor acerca das cidades.
Shear bond strength of self-etch and total-etch adhesives to bovine enamel and dentin
Raposo, Carolina Carramilo;Santana, Ivone Lima;
Revista Odonto Ciência , 2012, DOI: 10.1590/S1980-65232012000200009
Abstract: purpose: to evaluate the shear bond strength of a self-etch adhesive and an etch-and-rinse adhesive when bonded to bovine enamel and dentin. methods: the labial surfaces of 28 bovine mandibular incisors were wet ground to achieve a flat enamel or dentin surface. a 1-step self-etch adhesive and a 3-step etch-and-rinse adhesive were bonded to enamel or dentin according to the manufacturer's instructions (adper easy one and adper scotchbond, respectively). a composite resin cylinder (filtek z350 xt) was built upon the adhesive layer using a silicon mold (2 mm in diameter × 3 mm high). the specimens were stored in 37°c distilled water for 24 h. the bond strength was measured by a universal testing machine at a crosshead speed of 1.0 mm/min. student's t-test was used to compare bond strength values between adhesives at the 95% confidence level. results: for the enamel specimens, adper scotchbond had significantly higher values of bond strength than adper easy one (p=0.007). for the dentin specimens, there were no statistically significant differences between adhesives (p=0.12). conclusion: adper easy one showed lower shear bond strength than adper scotchbond on enamel. for dentin, adper easy one showed bond strength similar to adper scotchbond.
Shear bond strength of self-etch and total-etch adhesives to bovine enamel and dentin =Resistência ao cisalhamento de adesivo autocondicionante e convencional ao esmalte e dentina bovinos
Raposo, Carolina Carramilo,Santana, Ivone Lima
Revista Odonto Ciência , 2012,
Abstract: Objetivo: Avaliar a resistência ao cisalhamento de adesivo autocondicionante e adesivo convencional ao esmalte e dentina bovinos. Metodologia: As superfícies vestibulares de 28 incisivos mandibulares bovinos foram lixadas, sob refrigera o, para obten o de superfícies de esmalte ou dentina planas. Um adesivo autocondicionante de passo único e um convencional de três passos foram utilizados de acordo com as instru es dos fabricantes (Adper Easy One and Adper Scotchbond, respectivamente). Um cilindro de resina composta foi confeccionado sobre a camada adesiva usando um molde de silicone (2 mm de diametro × 3 mm altura). Os espécimes foram armazenados a 37°C em água destilada por 24 h. A resistência de uni o foi mensurada através de máquina de ensaios universal à velocidade de 0. 1 mm/min. Teste t de Student comparou os resultados de resistência de uni o entre os adesivos com nível de confian a de 95%. Resultados: Para os espécimes de esmalte, Adper Scotchbond apresentou valores significativamente maiores que Adper Easy One (P=0. 007). Para espécimes de dentina, n o houve diferen as significativas entre os adesivos (P=0. 12). Conclus o: Adper Easy One mostrou menor resistência ao cisalhamento do que Adper Scotchbond no esmalte. Para dentina, Adper Easy One mostrou resistência de uni o similar ao Adper Scotchbond. Purpose: To evaluate the shear bond strength of a self-etch adhesive and an etch-and-rinse adhesive when bonded to bovine enamel and dentin. Methods: The labial surfaces of 28 bovine mandibular incisors were wet ground to achieve a flat enamel or dentin surface. A 1-step self-etch adhesive and a 3-step etch-and-rinse adhesive were bonded to enamel or dentin according to the manufacturer’s instructions (Adper Easy One and Adper Scotchbond, respectively). A composite resin cylinder (Filtek Z350 XT) was built upon the adhesive layer using a silicon mold (2 mm in diameter × 3 mm high). The specimens were stored in 37°C distilled water for 24 h. The bond strength was measured by a universal testing machine at a crosshead speed of 1. 0 mm/min. Student’s t-test was used to compare bond strength values between adhesives at the 95% confidence level. Results: For the enamel specimens, Adper Scotchbond had significantly higher values of bond strength than Adper Easy One (P=0. 007). For the dentin specimens, there were no statistically significant differences between adhesives (P=0. 12). Conclusion: Adper Easy One showed lower shear bond strength than Adper Scotchbond on enamel. For dentin, Adper Easy One showed bond strength similar to Adper Scotchbond.
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