901 resultados para immersion of manifold


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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We demonstrate the efficacy of propofol (2,6-diisopropylphenol) as an anesthetic when administered to fish in an immersion bath and show the absence of genetic side effects following short-term exposure to the drug. All tested fish were anesthetized (as indicated by loss of posture and lack of response to physical stimulation), and both the comet assay (tail intensity) and the micronucleus assay revealed that propofol does not induce primary DNA damage or chromosome damage in the fish Nile Tilapia Oreochromis niloticus. Our results should be considered in light of our particular test conditions, including the water temperature (similar to 25 degrees C), the life stage and size of the fish, and the single exposure to the anesthetic. We suggest that propofol is a promising anesthetic in terms of its lack of genotoxic effects, at least in low dosages in adult Nile Tilapia.Received June 25, 2013; accepted October 15, 2013

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

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Amorphous silicon carbonitride (a-SiCN:H) films were deposited from hexamethyldisilazane (HMDSN) organic compounds via radio-frequency (RF) glow discharges. Afterwards the films were bombarded, from 15 to 60 min, with nitrogen ions using Plasma Immersion Ion Implantation (PIII) technique. X-ray photoelectron spectroscopy (XPS) showed that O-containing groups increased, while C-C and/or C-H groups decreased with treatment time. This result indicates chemical alterations of the polymeric films with the introduction of polar groups on the surface, which changes the surface wettability. In fact, the hydrophobic nature of a-SiCN:H films (contact angle of 100 degrees) was changed by nitrogen ion implantation and, and after aging in atmosphere air, all samples preserved the hydrophilic character (contact angle <80 degrees) independently of treatment time. The exposure of the films to oxygen plasma was performed to evaluate the etching rate, which dropped from 24% to 6% while the implantation time increased from 15 to 60 min. This data suggests that Pill increased the film structure strength, probably due to crosslinking enhancement of polymeric chains. Therefore, the treatment with nitrogen ions via Pill process was effective to modify the wettability and oxidation resistance of a-SiCN:H films. (C) 2014 Elsevier Ltd. All rights reserved.

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We determine the relation amongst the global Lê cycles and the Milnor classes of analytic hypersurfaces defined by a section of a very ample line bundle over a compact complex manifold. The key point is finding appropriate expressions for the global Lê cycles and for the Milnor classes in terms of polar varieties. Our starting points are an interpretation of the Lê cycles given by T. Gaffney and R. Gassler, a formula by A. Parusinski and P. Pragacz for the Milnor classes via McPherson’s functor, and a conjecture of J.-P. Brasselet, that we prove, stating that Milnor classes can be expressed in terms of polar varieties. We then use the work by R. Piegne for Mather classes, by J. Schürmann and M. Tibăr for MacPherson’s classes for constructible functions, and by D. Massey for an extension of the local Lê cycles for constructible sheaves.

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Direct immersion SPME-GC-MS-MS was used for the analysis of steroids in water at part-per-trillion(ppt) and lower concentrations. The method was validated and extended to real sample analysis. The method were linear from 0.01 to 5 ng/ml with precision less than 10% relative standard deviation for a steroid mixture at 1 ng/ml. Limit of quantitation and limit of detection was found to be 200- 1200 pg/L and 30-200 pg/L respectively and recoveries ranged from 88-103 %. To understand the extraction efficiency of the fiber, a depletion study was performed. The fiber/ sample partition coefficients for the steroids were determined to be 1.0 x 104 to 1.5 x 104 . The extraction was performed without derivatization or the use of an internal standard. SPMEGC-MS-MS effectively demonstrated ultra-trace level detection of steroids in water.

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Parasitism constitutes one of the main problems that affect livestock. Commercial acaricides have been used to control tick, but these chemicals have been responsible for the development of drug resistance and residues in the environment. Changes in the concept of production determined the search for natural measures, which guarantees animal sanity along with safety of the produced food. This assay had as objective to evaluate the citronella oil and neem oil in the control of bovine ticks. By the technique of adult ticks immersion, 280 ticks were evaluated, distributed in equal number throughout four treatments: negative control group, positive control (ivermectin), neem oil and citronella oil. It was analyzed the mortality index, estimated reproduction, product efficiency, index of eggs production and the hatchability rate. The efficiency of the product was verified by the mortality index just for the positive control group (100%) and citronella oil (97.14%). Also, the citronella oil inhibited the eclosion of eggs in 100%. The other treatments did not presented the minimum eclosion inhibition level of 95%. Under the conditions of the present assay citronella oil was efficient against Rhipicephalus (Boophilus) microplus. This result was not observed in relation to the neem oil.

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

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This study analyzes the clot stabilization on root surfaces of teeth impregnated with cotinine and nicotine and the influence of the scaling in the adhesion of blood components, observing the influence of new exposition to nicotine and/or cotinine after scaling. Fifteen human teeth extracted due to periodontal disease of non-smokers patients were selected and manually scaled. Four dentin blocks were obtained from each tooth (n = 60). Samples received blood application or reimpregnation with nicotine and/or cotinine, depending on the groups. Group 1: PBS immersion + root scaling + blood; group 2: nicotine + root scaling + blood; group 3: nicotine + root scaling + nicotine reapplication + blood; group 4: cotinine + root scaling + blood; group 5: cotinine + root scaling + cotinine reapplication+ blood; group 6: nicotine and cotinine + root scaling + nicotine and cotinine + blood. Samples were kept in 2 ml of each substance for 24 hours. Each group received a blood drop and was analyzed by SEM. The higher amount of blood components was present in teeth exposed to cotinine and the groups submitted to scaling and blood application in comparison with groups that received reapplication of toxic substances after scaling. The greater toxic effect on root dentin surface was after the exposure to nicotine and cotinine. Results suggest that periodontal healing may be delayed in smokers due to the direct inhibition of clot stabilization on the root surface when nicotine and cotinine are present concomitantly.

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The purpose of this study is to verify the effect of three different types of dentifrices on the superficial microhardness of bovine enamel. Methods: Forty-eight 4x4mm dental fragments were polished and randomly divided into 4 groups: GI, conventional silica-based dentifrice; GII, hydrogen peroxide-based dentifrice; GIII, carbamide peroxide-based dentifrice; and GIV, immersion in artificial saliva. After polished, the specimens received five indentations of 25g static load, for 5 seconds. Subsequently, specimens from groups GI, GII and GIII were immersed in solution containing dentifrice and distilled water, in weight proportion of 1:2, for 15 minutes daily. After this period, fragments were rinsed in tap water and stored in artificial saliva at 37oC. This procedure was repeated for 21 days and then a new analysis of the microhardness was performed. Results and conclusion: The results were submitted to ANOVA and Fisher’s test at 5%. It was concluded that all samples treated with dentifrices showed hardness decrease, being most pronounced in dentifrices containing peroxide.

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Composite resins are materials that can present color changing when exposed to pigments. Objective: The aim of this study was to evaluate, in vitro, the color changing of composites after immersion in different substances for different periods. Material and methods: Two microhybrid composite resins: Charisma (Heraeus – Kulzer) and Opallis (FGM) were used. Red wine and acai pulp were also used as immersion medium. For this study, 32 specimens with 10 mm of diameter and 2 mm of thickness were used, divided into 4 groups: Group 1 – Opallis composite immersed in red wine solution; Group 2 – Opallis composite immersed in acai berry pulp solution; Group 3 – Charisma composite immersed in red wine solution; Group 4 – Charisma composite immersed in acai berry pulp solution. The specimens were evaluated in the following time periods: T0 – baseline, T1 – 24 hours, T2 – 48 hours, T3 – 72 hours and T4 – 96 hours. For the assessment of staining, a spectrophotometer for colorimetry was used (Color Guide 45 / 0, PCB 6807 BYK-Gardner Gerestsried GmBH, Germany), and the values obtained were transferred to a computer and recorded according to CIELAB system. Results: The data were evaluated using Kruskal- Wallis non-parametric tests with the following mean values for the immersion periods of 24, 48, 72 and 96 hours, respectively: G1 – 7.35, 7.84, 9.04,10.48; G2 – 2.92, 4.15, 4.30, 4.64; G3 – 3.14, 7.35, 8.13, 8.43, G4 – 4.49, 5.99, 6.92, 6.76. Conclusion: Red wine showed a higher tendency toward altering the composite color than acai berry pulp. In addition, no significant difference was found concerning to the behavior of the two composite resins. Concerning to the immersion time periods, significant differences were only observed among the groups in the 24 hour time period.