Microstructural Characterization of Ti-6Al-7Nb Alloy After Severe Plastic Deformation

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

Evolution of representation of the hands in plastic arts

A interação entre arte e ciência foi intensa durante o Renascimento, sofrendo declínio nos anos posteriores com retomada significativa no século XX, principalmente com o uso de técnicas de identificação, datação de obras de arte e o desenvolvimento de novos materiais. O relacionamento entre artes plásticas e Cirurgia da Mão mantêm-se intenso , sendo freqüente o uso de reproduções artísticas da mão nas ilustrações de textos científicos. Objetivando compreender o papel da mão nas artes plásticas, reproduções de obras de artes (esculturas e pinturas) representativas de vários estilos ou períodos da história da arte foram analisadas com enfoque no estudo das mãos. Detalhes anatômicos, relacionamento com outras estruturas do corpo humano, papel na composição e aspectos simbólicos das mãos foram estudados no contexto histórico e artístico de obras de arte do período paleolítico (pré-história) até o século XX. A representação da mão nas artes plásticas está diretamente relacionada ao estilo ou período da obra e à capacidade individual de interpretação e execução do artista.

Comparison of synthetic hydroxyapatite and porous polyethylene implants in eviscerated rabbit eyes

Purpose: Synthetic hydroxyapatite and porous polyethylene (Polipore) spheres were placed in rabbits' eviscerated cavities to evaluate tissue reaction and volume maintenance.Methods. Fifty-six Norfolk albino rabbits underwent unilateral evisceration and implantation of synthetic hydroxyapatite (H group, 28 animals) or porous polyethylene spheres (P group, 28 animals). Postoperative reactions, animal behavior, and socket conditions were monitored. Light microscopy and morphometric evaluation with statistical analysis of the exenterated orbits were performed at 7, 15, 30, 60, 90, 120, and 180 days. Scanning electron microscopy was appraised 7, 60, and 180 days after surgery.Results: Two animals from the H group and 1 from the P group had extrusion 7 days after surgery. Throughout the experimental period, the synthetic hydroxyapatite caused more inflammation than the porous polyethylene material. Ingrowth in the sphere occurred 7 to 15 days after the surgery in both groups, and the tissue reaction became denser at approximate to60 to 90 days, when bony metaplasia began in the H group. Volume maintenance was better in the P group and with a smaller pseudocapsule surrounding the implanted sphere than in the H group.Conclusions: Clinical findings demonstrated mild inflammation inside the sphere and in the pseudocapsule surrounding it and better cavity volume maintenance in the P group animals. The authors consider porous polyethylene a more suitable material than synthetic hydroxyapatite for use in anophthalmic cavity reconstruction.

Time interval from ovulation to extrusion in female bullfrog in different photoperiods

It was analyzed in this work the influence of photoperiod on time interval from ovulation induction period to extrusion of ovocits in female bullfrogs (Lithobates catesbeianus). It was used 54 females reared from metamorphosis to 9 months of age under three photoperiods: dark time (DL 0:24), 16 hours of daylight (DL 16:8) and 12 hours of daylight (DL 12:12). Ovulation was induced by intramuscular application of two doses of LHRHa with 12 hours of interval between the injections. After 10, 25, 28, 31, 34 and 37 hours from the first hormone injection, 10-gram samples (3,000 eggs) were extracted from each female at each time interval and fertilized. Egg hatching rate was checked in each sample 72 hours after fertilization. Analysis of variance showed a significant effect of extrusion delay and the interaction between photoperiod and this delay. Extrusion should be carried out 33, 24 and 26 hours after the first hormone dosage in females reared in environments without light, with 12 hours of daylight and with 16 hours of daylight, respectively, to obtain the maximum fertilization rate.

Management of a complicated crown-root fracture using adhesive fragment reattachment and orthodontic extrusion

Dental trauma is more common in young patients and its sequelae may impair the establishment and accomplishment of an adequate treatment plan. This paper reports a case of complicated crown-root fracture in a young adult that was treated using adhesive tooth fragment reattachment and orthodontic root extrusion. Considering the time elapsed to follow up, the fracture extension, the amount of remaining root portion and the patient's low socioeconomic status, the treatment approach proposed for this case provided good functional and aesthetic outcomes. Clinical and radiographic results after 2 years were successful. This case report demonstrates the importance of establishing a multidisciplinary approach for a successful dental trauma management.

Treatment of a severe dental lateral luxation associated with extrusion in an 8-month-old baby: a conservative approach

This case report documents the trauma and follow-up care of lateral luxation associated with extrusion of the lower central incisors in an 8-month-old patient. The teeth were repositioned by digital pressure and stabilized using proximal sutures. Clinical and radiographic follow-up 40 months after the injury showed alterations in both incisors, but both remained functional and free of pathology.

Comparison of the Accuracy of Plastic and Metal Stock Trays for Implant Impressions

Purpose: This in vitro study evaluated the dimensional accuracy of two impression techniques (tapered and splinted) with two stock trays (plastic and metal) for implant-supported prostheses. Materials and Methods: A master cast with four parallel abutment analogs and a passive framework were fabricated. Polyvinyl siloxane impression material was used for all impressions with two metal stock trays and two plastic stock trays (closed and open trays). Four groups (tapered plastic, splinted plastic, tapered metal, and splinted metal) and a control group (master cast) were tested (n = 5 for each group). After the framework was seated on each of the casts, one abutment screw was tightened, and the marginal gap between the abutment and framework on the other side was measured with a stereomicroscope. The measurements were analyzed with the Kruskal-Wallis one-way analysis of variance on ranks test followed by the Dunn method. Results: The mean values (+/- standard deviations) for the abutment/framework interface gaps were: master cast, 32 +/- 2 mu m; tapered metal, 44 +/- 10 mu m; splinted metal, 69 +/- 28 mu m; tapered plastic, 164 +/- 58 mu m; splinted plastic, 128 +/- 47 mu m. No significant difference was detected between the master cast, tapered metal, and splinted metal groups or between the tapered and splinted plastic groups. Conclusions: In this study, the rigidity of the metal stock tray ensured better results than the plastic stock tray for implant impressions with a high-viscosity impression material (putty). Statistically similar results were obtained using tapered impression copings and splinted squared impression copings. The tapered impression copings technique and splinted squared impression copings technique with a metal stock tray produced precise casts with no statistically significant difference in interface gaps compared to the master cast. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:544-550.

The effects of extrusion conditions and the addition of volatile compounds and flavour enhancers to corn grits on the retention of the volatile compounds and texture of the extrudates

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

Machined and plastic copings in three-element prostheses with different types of implant-abutment joints: a strain gauge comparative analysis

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

Automatic Classification of Three-Phase Flow Patterns of Heavy Oil in a Horizontal Pipe Using Support Vector Machines

The pipe flow of a viscous-oil-gas-water mixture such as that involved in heavy oil production is a rather complex thereto-fluid dynamical problem. Considering the complexity of three-phase flow, it is of fundamental importance the introduction of a flow pattern classification tool to obtain useful information about the flow structure. Flow patterns are important because they indicate the degree of mixing during flow and the spatial distribution of phases. In particular, the pressure drop and temperature evolution along the pipe is highly dependent on the spatial configuration of the phases. In this work we investigate the three-phase water-assisted flow patterns, i.e. those configurations where water is injected in order to reduce friction caused by the viscous oil. Phase flow rates and pressure drop data from previous laboratory experiments in a horizontal pipe are used for flow pattern identification by means of the 'support vector machine' technique (SVM).

Screening of melon populations for resistance to Didymella bryoniae in greenhouse and plastic tunnel conditions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of a double-setting alpha-tricalcium phosphate cement in eviscerated rabbit eyes

Purpose: To evaluate the macroscopy, microstructure, and tissue reaction of a double-setting a-tricalcium phosphate bone cement used as an intraocular implant in rabbits.Methods: the internal and external surface of the double-setting a-tricalcium phosphate implant was analyzed macroscopically and by scanning electron microscopy. Twelve New Zealand rabbits received 12-mm implants made of double-setting alpha-tricalcium phosphate cement after unilateral evisceration. Clinical evaluation was performed daily for the first 15 days after surgery and at 15-day intervals until the end of the study period. For histopathologic analysis, 3 animals per experimental period were submitted to enucleation at 15, 45, 90, and 180 days.Results: on gross inspection, the external surface of the implant was solid, smooth, and compact. The microarchitecture was characterized by the formation of columns of hexagonal crystals with interconnecting channels forming micropores. No wound dehiscence, signs of infection, or implant extrusion were observed in any animal throughout the study period. Histologic examination revealed the formation of fibrovascular tissue surrounding the implants, and there were signs of minimal integration of the surface limiting the fibrocellular cap with the space previously occupied by the implant.Conclusions: the double-setting alpha-tricalcium phosphate implant behaved as an inert and nonintegratable material. The lack of incorporation of this material by fibrovascular tissue is related to its characteristics of compactness and high resistance.

A probabilistic model for elastic-plastic fracture analysis of plane and axisymmetric structures

This work presents a methodology for elastic-plastic fracture reliability analysis of plane and axisymmetric structures. The structural reliability analysis is accomplished by means of the FORM analytical method. The virtual crack extension technique based on a direct minimization of potencial energy is utililized for the calculation of the energy release rate. Results are presented to illustrate the performance of the adopted methodology.

Elasto-plastic structural stability of arches

The elastic-plastic structural stability behaviour of arches is analysed in the present work.The application of the developed mathematical model, allows to determine the elastic-plastic equilibrium paths, looking for critical points, bifurcation or limit, along those paths, associated to the critical load, in case it comes to happen.The equilibrium paths in the elastic-plastic behaviour when compared with the paths in the linear elastic behaviour, may show that, due to influence of the material plasticity, modifications paths appear and consequently alterations in the values of its critical loads.