8 resultados para “Magic Glasses” video
em Scielo Saúde Pública - SP
Resumo:
OBJECTIVE: To assess, in a prospective way, the experience with video-assisted pericardioscopy obtained in patients with pericardial effusion of unclear etiology in the preoperative period. METHODS: From January 1998 to June 2000, 20 patients were operated upon with the aid of video-assisted pericardioscopy. On echocardiography, 17 of these patients had significant pericardial effusion, and 3 had moderate pericardial effusion. Video-assisted pericardioscopy was performed through a small incision of the Marfan type. RESULTS: The diagnosis of pericardial effusion was established as follows: idiopathic in 9 (45%) patients, neoplastic in 4 (20%), resulting from hypothyroidism in 3 (15%), tuberculous in 2 (10%), due to cholesterol in 1 (5%), and chylopericardial in 1 (5%). The biopsy was positive in 30% of the patients, and the etiology could not be defined in 45% of the patients. CONCLUSION: Video-assisted pericardioscopy proved to be a method with low morbidity and a high index of diagnostic positivity. A high percentage of pericardial effusions are caused by viral infections, which are not diagnosed through current methods, being, therefore, classified as idiopathic.
Resumo:
Their extended transparency in the IR makes them attractive for use as optical fibers for CO laser power delivery and optical amplification. This paper firstly describes the spectacular stabilizing effect of MgF2 on the binary system InF3-BaF2. The investigation of the InF3-BaF2-MgF2 system led to samples up to 5mm in thickness. Further optimization of this system was achieved by incorporation of limited amounts of other fluorides and resulted in increased resistence to devitrification. The second approach of this work was concerned to the investigation of the pseudo-ternary system InF3-GdF3-GaF3 at constant concentrations of ZnF2-SrF2-BaF2-NaF. Several compositions were studied in this system. The samples presented a better thermal stability when compared to other families of fluoride glasses. Therefore, these glasses seem to be very promising for the fabrication of special optical fibers. Thermal data are reported.
Resumo:
In this paper, glasses in the systems In-Ba-Mg and In-Ba-Zn-Sr-Mg were water leachead at 80ºC showing surface degradation after 72 hours of leaching. The extent of such degradation is determined by the solubility and the concentration of the elemental fluorides that constitute the glasses. The formation of a layer of crystallized phases on the surface of the samples was observed. Small weight losses were registered and the absence of water on the glass matrix after the attack suggested that the use of MgF2 in the systems studied can lead to better results against moisture corrosion when compared to other fluoride glasses such as the fluorozirconates.
Resumo:
Fabrication of new optical devices based upon the incorporation of rare earth ions via sol-gel methods depends on elimination of dopant ion clusters and residual hydroxyl groups from the final material. The optical absorption and/or luminescence properties of luminescent rare earth ions are influenced by the local bonding environment and the distribution of the rare-earth dopants in the matrix. Typically, dopants are incorporated into gel via dissolution of soluble species into the initial precursor sol. In this work, Eu3+ is used as optical probe, to assess changes in the local environment. Results of emission, excitation, fluorescence line narrowing and lifetimes studies of Eu3+-doped gels derived from Si(OCH3)4 and fluorinated/chelate Eu3+ precursors are presented. The precursors used in the sol-gel synthesis were: tris (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) Eu(III), Eu (III) trifluoromethanesulfonate, Eu(III) acetylacetonate hydrate, Eu (III) trifluoroacetate trihidrate, tris (2,2,6,6-tetramethyl-3,5- heptanedionate) Eu(III) and Eu(NO3)3.6H2O. The results were interpreted in terms of the evolution of the Eu3+ fluorescence in systems varying from solution to the gels densified to 800ºC. The lifetimes studies indicate that the fluorinated precursors are effective at reducing the water content in densified gels.
Resumo:
In this work it is carried out a review on structural parameters related to the evaluation of pore connectivity of nanostructures. The work describes parameters and methods of evaluation of geometric parameters. The concepts of connectivity are applied to silica gels and glasses obtained from sol-gel process. The study of pores connectivity was carried out using a combination of geometric modeling and experimental evaluation of specific surface area and pore volume. The permeability of the pore structure is evaluated and a permeability geometric factor, Pg, is proposed.
Resumo:
The application of one-dimensional proton high-resolution magic angle spinning (¹H HR-MAS) NMR combined with a typical advantages of solid and liquid-state NMR techniques was used as input variables for the multivariate statistical analysis. In this paper, different cultivars of beans (Phaseolus vulgaris) developed and in development by Embrapa - Arroz e Feijão were analyzed by ¹H HR-MAS, which have been demonstrated to be a valuable tool in its differentiation according chemical composition and avoid the manipulation of the samples as used in other techniques.
Resumo:
Silver containing heavy metal oxide glasses and glass ceramics of the system WO3-SbPO4-PbO-AgCl with different AgCl contents have been prepared and their thermal, structural and optical properties characterized. Glass ceramics containing metallic silver nanoparticles have been prepared by annealing glass samples at temperatures above the glass transition and analyzed by transmission electron microscopy and energy dispersive X-ray microanalysis. The presence of the metallic clusters has been also confirmed by the observation of a surface plasmon resonance band in the visible range. Cyclic voltammetric measurements indicated the presence of metallic silver into the glasses, even before to perform the thermal treatment.
Resumo:
Objective: To evaluate perioperative outcomes, safety and feasibility of video-assisted resection for primary and secondary liver lesions. Methods : From a prospective database, we analyzed the perioperative results (up to 90 days) of 25 consecutive patients undergoing video-assisted resections in the period between June 2007 and June 2013. Results : The mean age was 53.4 years (23-73) and 16 (64%) patients were female. Of the total, 84% were suffering from malignant diseases. We performed 33 resections (1 to 4 nodules per patient). The procedures performed were non-anatomical resections (n = 26), segmentectomy (n = 1), 2/3 bisegmentectomy (n = 1), 6/7 bisegmentectomy (n = 1), left hepatectomy (n = 2) and right hepatectomy (n = 2). The procedures contemplated postero-superior segments in 66.7%, requiring multiple or larger resections. The average operating time was 226 minutes (80-420), and anesthesia time, 360 minutes (200-630). The average size of resected nodes was 3.2 cm (0.8 to 10) and the surgical margins were free in all the analyzed specimens. Eight percent of patients needed blood transfusion and no case was converted to open surgery. The length of stay was 6.5 days (3-16). Postoperative complications occurred in 20% of patients, with no perioperative mortality. Conclusion : The video-assisted liver resection is feasible and safe and should be part of the liver surgeon armamentarium for resection of primary and secondary liver lesions.