892 resultados para fracture and deformation concepts
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Purpose: The objective of this study was to carry out a comparative evaluation of the mechanical resistance of 2 rigid internal fixation techniques for fractures of the mandibular condyle using miniplates.Materials and Methods: Fort), polyurethane resin replicas of human hemimandibles were used. The hemimandibles were sectioned to simulate a high subcondylar fracture and then stabilized with 2 fixing techniques using 2.0-mm system plates and screws. The fixation techniques were 2 separate 4-hole plates with 8 screws, and 2 overlaid 4-hole plates with 4 screws. Each system was submitted to load tests, with the application of the load in mediolateral and anteroposterior directions in an Instron 4411 universal assay machine (Instron, Norwood, MA).Results: Load values and peak displacement were measured. Means and standard deviations were evaluated by analysis of variance (P < .05) and Tukey tests, in which it was verified that the anteroposterior peak load value was affected by the arrangement of the plates on the models, although no differences were observed between the groups for the mediolateral peak load. The arrangement of the plates did not have any influence on peak displacement. Similarly, the final value of the mediolateral load was not affected by the arrangement of the plates on the model.Conclusion: The experimental model with 2 separate plates was statistically superior to the model with 2 overlaid plates only in relation to anteroposterior peak load. Despite showing superiority in mediolateral peak load and peak displacement, there was no statistical difference between the groups for these parameters. (C) 2009 American Association of Oral and Maxillofacial Surgeons
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Purpose: To evaluate a bone morphogenetic protein (BMP) implant with and without platelet-rich plasma (PRP), which is supposed to accelerate fracture consolidation in the orbit fracture treatment. Methods: Thirty-six white rabbits were subjected to orbital fracture and treated in three groups: BMP implant fracture repair (G1), BMP plus PRP implant fracture repair (G2), and fracture and spontaneous repair (G3). The animals were sacrificed at 7, 30, 90, and 180 days after surgery. A radiology evaluation was carried out on the 7th day after the fracture and at the sacrifice moments. After the animals' death, the orbital content material was removed and prepared for morphological and morphometric analysis. Results: Radiology suggested intramembranous and progressive cavitation and ossification without a reduction in implant size and with signs of calcium deposition; these events were confirmed by histological analysis, which showed a lymphomononuclear inflammatory reaction in G1 and G2, more intense 7 days after surgery and reducing after 30 days. Associating PRP with BMP did not accelerate bone induction. Conclusion: BMP implant promotes bone induction, integration at fracture site, scarce inflammatory reaction, and may be a good alternative in orbit fracture reconstruction. The addition of PRP to the BMP plate did not accelerate the resolution, and its use is not necessary. Copyright © Informa Healthcare USA, Inc.
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Automotive parts manufacture by machining process using silicon nitride-based ceramic tool development in Brazil already is a reality. Si 3N4-based ceramic cutting tools offer a high productivity due to their excellent hot hardness, which allows high cutting speeds. Under such conditions the cutting tool must be resistant to a combination of mechanical, thermal and chemical attacks. Silicon nitride based ceramic materials constitute a mature technology with a very broad base of current and potential applications. The best opportunities for Si3N 4-based ceramics include ballistic armor, composite automotive brakes, diesel particulate filters, joint replacement products and others. The goal of this work was to show latter advance in silicon nitride manufacture and its recent evolution on machining process of gray cast iron, compacted graphite iron and Ti-6Al-4V. Materials characterization and machining tests were analyzed by X-Ray Diffraction, Scanning Electron Microscopy, Vickers hardness and toughness fracture and technical norm. In recent works the authors has been proved to advance in microstructural, mechanical and physic properties control. These facts prove that silicon nitride-based ceramic has enough resistance to withstand the impacts inherent to the machining of gray cast iron (CI), compacted graphite iron (CGI) and Ti-6Al-4V (6-4). Copyright © 2008 SAE International.
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Purpose: This study aims to review anatomical, clinical, and pathological concepts as well as to discuss the most adequate therapeutic approach to the mucoceles of the glands of Blandin-Nuhn. Discussion: The glands of Blandin-Nuhn are localized in the ventral part of the tongue, next to the apex in the lingual median plane. Development of a mucocele in this site is rarely seen; besides, as the glands of Blandin-Nuhn are not encapsulated and are directly overlapped to the muscle tissues, their manipulation tends to be different from the other oral mucoceles. Conclusion: As Blandin-Nuhn mucoceles are uncommon and their clinical appearance could be similar to other lesions, it is important that health professionals know their clinical and histopathological features to avoid having them misdiagnosed. © 2010 Springer-Verlag.
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Metal machining is the complex process due the used cutting parameters. In metal cutting process, materials of workpiece differ widely in their ability to deform plastically, to fracture and to sustain tensile stresses. Moreover, the material involved in the process has a great influence in these operations. The Ti-6Al-4V alloy is very used in the aeronautical industry, mainly in the manufacture of engines, has very important properties such the mechanical and corrosion resistance in high te mperatures. The turning of the Ti-Al-4V alloy is very difficult due the rapid tool wear. Such behavior result of the its low thermal conductivity in addition the high reactivity with the cutting tool. The formed chip is segmented and regions of the large deformation named shear bands plows formed. The machinability of the cutting process can be evaluated by several measures including power consume, machined surface quality, tool wear, tool life, microstructure and morphology of the obtained chip. This paper studies the effect of cutting parameters, speed and feed rates, in the tool wear and chip properties using uncoating cemented carbide tool. Microe-structural characterization of the chip and tool wear was performed using scanning electron microscopy (SEM) and Light Optical Mcroscopy (LOM).
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Includes bibliography
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The orbit is an irregular conical cavity formed from 7 bones including the frontal, sphenoid, zygomatic, maxillary, ethmoid, lacrimal, and palatine bones. Fractures of the internal orbit can cause a number of problems, including diplopia, ocular muscle entrapment, and enophthalmos. Although muscle entrapment is relatively rare, diplopia and enophthalmos are relatively common sequelae of internal orbital fractures. Medial orbital wall fracture is relatively uncommon and represents a challenge for its anatomical reconstruction. In this context, autogenous bone graft has been the criterion standard to provide framework for facial skeleton and orbital walls. Therefore, it is possible to harvest grafts of varying size and contour, and the operation is performed through the bicoronal incision, which is the usual approach to major orbital reconstruction. Thus, this article aimed to describe a patient with a pure medial orbital wall fracture, and it was causing diplopia and enophthalmos. The orbital fracture was treated using autogenous bone graft from calvarial bone. The authors show a follow-up of 12 months, with facial symmetry and without diplopia and enophthalmos. In addition, a computed tomography scan shows excellent bone healing at the anterior and posterior parts of the medial orbital wall reconstruction. Copyright © 2013 by Mutaz B. Habal, MD.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
The status of millennium development goals: monitoring and reporting in selected Caribbean countries
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In spite of various initiatives, Caribbean countries continue to have difficulties in addressing demands of monitoring and measuring progress towards the fulfilment of the Millennium Development Goals (MDGs) and other Internationally Agreed upon Development Goals (IADGs)1. To address this gap, the Economic Commission for Latin America and the Caribbean (ECLAC) has received funding for a technical assistance project, Strengthening the capacity of National Statistical Offices (NSOs) in the Caribbean Small Island Developing States to fulfil the Millennium Development Goals and other Internationally Agreed Development Goals (IADGs). The main imperative of the project is to support the strengthening of national institutional capabilities for generating reliable data to meet these monitoring and reporting requirements. The project seeks to build on past and current initiatives directed towards broadening and improving statistics and indicators through the use of already available knowledge, experience and expertise at the national and regional level. In an effort to avoid duplication of present or repetition of past activities in this field, ECLAC considered it important to conduct a thorough assessment of the status and structure of MDG and IADG monitoring and reporting at the national and regional levels as well as to provide an overview of initiatives undertaken by other regional development partners and intergovernmental bodies in the subregion. This paper is composed as follows: The first chapter of the document will present an overview of the statistical infrastructure at the national level, followed by a summary of the results of a survey administered to Caribbean NSOs that gathered information on the status of and mechanisms in place in MDG and IADG monitoring and reporting at the national level. Then, an attempt will be made to provide a briefing on activities carried out by intergovernmental bodies and development partners in the region. The fourth section presents a brief summary of data sources for secondary data and introduces concepts for metadata collection and reporting. It further discusses major challenges with poverty measurements and monitoring in the subregion. The paper ends with a summary and recommendations for the way forward.
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Pós-graduação em Geologia Regional - IGCE
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This study assessed the attitudes about the inclusion of students with disability by professionals in education and health, relative to their experience and training. We compared three groups: 20 teachers and trainees who worked in an adapted physical education program (GI); 75 professionals from the municipal education system of Rio Claro subdivided according to their experience-CGyes e CGno, respectively, with and without experience. We used the inventory adapted by Palla (2001) to assess participants' attitudes and self-concepts. Overall, individuals in the group that participated in the intervention maintained their tendency of being favorable toward inclusion. Teachers in regular school settings in the municipal school system of Rio Claro (Sao Paulo, Brazil), regardless of their experience with inclusive settings, remain mostly indecisive about the benefits of inclusion.
Microstructural and electrochemical characterization of friction stir welded duplex stainless steels
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Adhesive restorations have increasingly been used in dentistry, and the adhesive system application technique may determine the success of the restorative procedure. The aim of this study was to evaluate the influence of the application technique of two adhesive systems (Clearfil SE Bond and Adper Scotchbond MultiPurpose) on the bond strength and adhesive layer of composite resin restorations. Eight human third molars were selected and prepared with Class I occlusal cavities. The teeth were restored with composite using various application techniques for both adhesives, according to the following groups (n = 10): group 1 (control), systems were applied and adhesive was immediately light activated for 20 seconds without removing excesses; group 2, excess adhesive was removed with a gentle jet of air for 5 seconds; group 3, excess was removed with a dry microbrush-type device; and group 4, a gentle jet of air was applied after the microbrush and then light activation was performed. After this, the teeth were submitted to microtensile testing. For the two systems tested, no statistical differences were observed between groups 1 and 2. Groups 3 and 4 presented higher bond strength values compared with the other studied groups, allowing the conclusion that excess adhesive removal with a dry micro-brush could improve bond strength in composite restorations. Predominance of adhesive fracture and thicker adhesive layer were observed via scanning electron microscopy (SEM) in groups 1 and 2. For groups 3 and 4, a mixed failure pattern and thinner adhesive layer were verified. Clinicians should be aware that excess adhesive may negatively affect bond strength, whereas a thin, uniform adhesive layer appears to be favorable. (Quintessence Int 2013;44:9-15)
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During the management of the crisis after the earthquake occurred in Haiti in 12 January 2010, Brazil played an important role on the efforts of humanitarian assistance. Based on bibliography and documents the paper presents the role played by Brazil with the focus on the humanitarian assistance as part of country’ foreign policy as an emerging power to increase the presence into the international system. To achieve this goal the article presents some considerations about emerging powers, foreign policy and theoretical concepts about humanitarian assistance and international relations, the extension of the earthquake in Haiti and the actions performed by Brazil during the response phase of the crisis management.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)