798 resultados para Broca gigante
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Objective: The aim of this study was to evaluate the pH of calcium hydroxide (CalenTM) when associated or not with chlorhexidine 0.4%, and when associated with chlorhexidine with the addition of 20% or 10% of alphatocopherol (AchéTM), assessed in several periods of time. Methods: Fourty dentine tubes 20 mm, properly standardized, were made from bovine anterior teeth roots. Following, a perforation was achieved in the roots distal face at 7 mm from the cervical radicular line by using a #1/2 carbide bur. After complete root sealing is made, except in the perforation local, the radicular canals were filled with one of the following associations: Group I – Calen®; Group II – Calen™ with chlorehxidine at 0.4%; Group III – Calen™ with chlorhexidine at 0.4% with the addition of 20% (weight) of alhatocopherol compound and Group IV – Calen™ with chlorhexidine at 0.4% with the addition of 10% (weight) alphatocopherol. After cervical sealing is accomplished, the roots were immersed in water MiliQ and the pH, assessed in 24h, 7, 14, 21, 28 and 45 days. Results and Conclusion: In all periods tested, the pH of the calcium hydroxide (Calen™) was similar to the pH of the calcium hydroxide (Calen™) associated with chlorhexidine 0.4% and 10% alphatocopherol (p > 0.05). The association of 20% alphatocopherol obtained the pH lower than the association with 10% (p < 0.05). The pH of the association with chlorhexidine was similar to the pure calcium hydrocide (Calen™) after the 14th day (p > 0.05) only. Therefore, on the 45th day, this difference was significant again (p < 0.05).
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The Portland cement has shown similar biological properties to calcium hydroxide, but its radiopacity is lower. Therefore, the addition of materials that minimize this deficiency should be considered. OBJECTIVE: To evaluate the apical sealing ability and pH of a white Portland cement added of several radiopacifying agents. MATERIAL AND METHODS: Forty bovine roots with incomplete apices were selected, and the foraminal openings were standardized to PM 720G bur. After the external root sealing, an apical intracanal barrier 10.0 mm thick was executed with the white Portland cement powder, pure or added of a radiopacifying agent (iodoform, zinc oxide or bismuth subnitrate), and distilled water (0.37 mL). The apical roots were immersed 24h in water in humid atmosphere, and after that they were immersed 24h in 2% Rhodamine B, under vacuum. In sequence, the roots were longitudinally sectioned, the root fragments were photographed, the images were digitalized and the apical infiltration was measured by the Image Tool program. The pH solutions were also evaluated, in 24h and 48h and 7 and 30 days. Data were submitted to Anova test. RESULTS: The zinc oxide solution has the lowest apical infiltration in relation to the other groups (p < 0.05). The pH behavior varied during the analysis, and in the period of 24h all groups showed the highest values (p < 0.05). CONCLUSION: The type of radiopacifying agent used interferes in the sealing ability of the apical barrier, and zinc oxide showed to be the most beneficial one. The pH varies according to the period of analysis, and the highest values were obtained in the first 24h (p < 0.05).
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The adhesiveness of six root canal sealers: Acroseal, Endo CPM, Epiphany, White MTA, Sealapex and Sealer 26 to dentin, was evaluated in a push-out test design. Methods: Twenty eight roots of freshly extracted teeth were gauged with a size 5 Largo drill. With a cutting machine slices of 2 mm were prepared, rinsed with 5.25% NaOCl and a final rinse with 17% EDTA, dried and filled with one of the sealers. After setting their bond strength was measured in a mechanical testing machine. The data were statistically analyzed by using a One Way ANOVA and post hoc Tukey test. Results: The mean and standard deviation from values of bond strength was: Sealapex 2.2±0.4; Endo CPM 3.8±1.3; White MTA 6.0±1.4; Epiphany 10.9±2.6; Sealer 26 12.3±2.3; and Acroseal 12.2±1.4. Acroseal, Sealer 26 and Epiphany presented a significantly (P<0.01) greater bond strength compared with the other sealers. Also White MTA showed higher adhesiveness compared with Endo CPM and Sealapex (P<0.01). Conclusion: The bond strength between endodontic sealers and root dentin was maximal when Acroseal, Sealer 26 and Epiphany were used; Sealapex e Endo CPM, in turn, presented the lowest bond strength mean values.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The aim of this study was to evaluate the fracture resistance of simulated immature teeth after different intra-radicular treatments. Crowns and roots of bovine incisors were cut transversally and removed to simulate immature teeth. Root canal preparation and flaring were performed using a bur in crown-apex and apex-crown direction. The samples were distributed into 5 groups (n=10): Positive control (PoC) - no root canal flaring or filling; Negative control (NeC) - teeth were sectioned and their root canals were flared; Direct anatomical glass fiber post (RaP) - #2 Reforpost main glass fiber post relined with composite resin; Double tapered conical glass fiber posts (ExP) - #3 Exacto glass fiber post; and #2 Reforpost main glass fiber + Reforpin accessory glass fiber posts (RrP). In RaP, ExP and RrP, 4.0-mm apical plugs were done with MTA Angelus. The specimens were embedded in polystyrene resin inside cylinders and the periodontal ligament was simulated with a polyether-based impression material. The specimens were submitted to compressive fracture strength test (0.5 mm/min at 135° relative to the long axis of the tooth) in a servo-hydraulic mechanical testing machine MTS 810. Data were subjected to one-way ANOVA and Dunnett's C or Tukey's tests (α=0.05). The control groups (PoC and NeC) showed lower fracture strength than the experimental groups. NeC presented the lowest resistance and ExP presented the highest resistance among the experimental groups. The flaring procedures produced a detrimental effect on the fracture resistance of the bovine teeth. Glass fiber intra-radicular posts increased significantly the fracture resistance of simulated immature teeth.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Agronomia (Horticultura) - FCA
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Ascia monuste orseis (Godart) (Lepidoptera: Pieridae) is a production limiting pest in collard greens, Brassica oleracea (L.) var. acephala, cultivation. Because of the overuse and harmful effects of synthetic insecticides on nontarget species, the use of insect-resistant cultivars can be a valuable strategy in pest control. In this study, newly hatched A. monuste orseis larvae were confined to the leaves of 29 collard greens cultivars under a controlled environment to investigate plant resistance. We evaluated the incubation period, duration of instars, total duration of the immature and pupal phases, the egg to adult life cycle duration, mortality per instar, total weight of fifth instar larvae and pupae (age = 24 h) and larval and pupal survival and eclosion. Antibiosis and/or antixenosis were observed in selected cultivars. The results show that Gigante I-915 (E) exhibited high larval mortality and that the Pires 1 de Campinas cultivar (P) prevented all pupae from proceeding to the adult stage. The Introdu double dagger es do municipio de Arthur Nogueira Z (Y), Cabocla (AA), Japonesa (R) and Manteiga de Mococa (M) cultivars prolonged the larval stage. Japonesa (R) and Introdu double dagger es do municipio de Arthur Nogueira Z (Y) increased the egg to adult developmental period, and the Japonesa (R) cultivar also prolonged the pupal stage. The Verde-escura (O), Crespa de Capo Bonito (I), Couve de folhas Manteiga 900 Legitima P, Alto (AB), Gigante I-915 (E) and Manteiga Ribeiro Pires I-2446 (H) cultivars reduced the larval weight of A. monuste orseis.
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The transgenic application of green fluorescent protein (GFP) as fetal cell marker on cattle cloned placenta could provide an exclusive model for studying the morphologic and immunologic maternal-fetal interactions, providing information about its mapping, distinguishing the fetal from maternal cells. This model will have direct application, mainly because these animals present problems during its development. With this model's support, we intend to verify the substances transport between mother and fetus during endocytosis, through the immunolocalization of protein named caveolae. For these, we used 06 cloned bovine and 30 cattle samples of artificial insemination (AI) with 90 days of pregnancy, which had been their development interrupted by humanitarian slaughter of the recipient and recovery of the pregnant uterus. We collected the placentome and the chorion. A part of the samples was cut and fixed, by immersion, on a solution containing 4% of parafomaldehyde or 10% of formaldehyde on a sodium phosphate buffer (PBS), at 0,1 M pH 7.4, Zamboni solution (4% of paraformaldehyde, 15% of picric acid, on sodium phosphate buffer 0,1 M pH 7.4), metacarn (60% of metanol, 30% of chloroform, and 10% glacial acetic acid), for morphologic and immunohistochemistry verification for caveolinas proteins -1 and -2 (CAV -1 and CAV-2). The caveolins -1 were found in fetal and maternal villi, but its strongest staining was observed in the endometrial stroma. The caveolins -2 had positive staining in trophoblast and chorioallantoic membrane, and specifically in giant trophoblastic binucleated cell. Therefore the results were compared between cloned cattle and from AI or natural mating, for assisting on detection of the reason of many placental alterations, embryonic losses, spontaneous abortion, post-natal mortality and large offspring syndrome on laboratory-manipulated animals. The result suggests that the proteins caveolins -1 and -2 (CAV-1 and CAV-2) are part of the caveolae composition and important structures related to the molecule transfer to the fetus, nourish it through endocytosis and pinocytosis.