46 resultados para 1091


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A 1000-kgf resistive strain-gauge load cell has been developed for quality testing of rocket propellant grain. A 7075-T6 aluminum alloy has been used for the elastic column, in which 8 uniaxial, 120-Ω strain gauges have been bonded and connected to form a full Wheatstone bridge to detect the strain. The chosen geometry makes the transducer insensitive to moments and, also, to the temperature. Experimental tests using a universal testing machine to imposed compression force to the load cell have demonstrated that its behavior is linear, with sensitivity of 2.90 μV/kgf ± 0.34%, and negligible hysteresis. The designed force transducer response to a dynamic test has been comparable to that of a commercial load cell. © 2005 IEEE.

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IEEE 1451 Standard is intended to address the smart transducer interfacing problematic in network environments. Usually, proprietary hardware and software is a very efficient solution to in planent the IEEE 1451 normative, although can be expensive and inflexible. In contrast, the use of open and standardized tools for implementing the IEEE 1451 normative is proposed in this paper. Tools such as Java and Phyton programming languages, Linux, programmable logic technology, Personal Computer resources and Ethernet architecture were integrated in order to constructa network node based on the IEEE 1451 standards. The node can be applied in systems based on the client-server communication model The evaluation of the employed tools and expermental results are presented. © 2005 IEEE.

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An 8051-based microcontroller tester has been designed to reduce troubleshooting time of the Electro-Hydraulic Actuators (EHA) installed in fly-by-wire aircrafts. The tester algorithm first evaluates EHA pressure and position sensor signals to emit either a pass or fail message. The evaluation is based on predefined ranges of EHA pressure and position signals. Next, the instrument tests the EHA response capability - a way of dynamic response evaluation, again issuing a suitable response. The instrument proved to be reliable after being successfully evaluated in laboratory and in a real model test airplane. © 2007 IEEE.

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Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light- to dark-brown macules on sun-exposed skin areas. The literature shows few studies on its physiopathogeny. However, changes in α-melanocyte stimulating hormone (α-MSH) secretion and melanocortin-1 receptor (MC1-R) expression may play a role to trigger this condition. Biopsies were taken from both melasma skin and adjacent perilesional normal skin of 44 patients. The biopsies were submitted for hematoxylin and eosin and Fontana-Masson staining and immunohistochemistry with Melan-A, α-MSH, and MC1-R, and processed for transmission electron microscopy. In some cases, they were submitted to MC1-R gene expression analysis by real-time polymerase chain reaction. Increased lymphohistiocytic infiltrate and solar elastosis, higher epidermal melanin were observed in melasma skin. Electron microscopy revealed a greater number of mature melanosomes in keratinocytes and melanocytes, and more prominent cytoplasmic organelles in melasma skin. There was no difference in melanocyte number between areas. However, melanocytes were larger and more dendritic in melasma skin. Immunohistochemistry with α-MSH and MC1-R showed significant labeling in melasmic epidermis but MC1-R messenger ribonucleic acid (RNAm) did not show significant quantitative difference between melasma and normal skin. © 2010 by Lippincott Williams & Wilkins.

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This paper considers the importance of using a top-down methodology and suitable CAD tools in the development of electronic circuits. The paper presents an evaluation of the methodology used in a computational tool created to support the synthesis of digital to analog converter models by translating between different tools used in a wide variety of applications. This tool is named MS 2SV and works directly with the following two commercial tools: MATLAB/Simulink and SystemVision. Model translation of an electronic circuit is achieved by translating a mixed-signal block diagram developed in Simulink into a lower level of abstraction in VHDL-AMS and the simulation project support structure in SystemVision. The method validation was performed by analyzing the power spectral of the signal obtained by the discrete Fourier transform of a digital to analog converter simulation model. © 2011 IEEE.

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This paper presents a NCAP embedded on DE2 kit with Nios II processor and uClinux to development of a network gateway with two interfaces, wireless (ZigBee) and wired (RS232) based on IEEE 1451. Both the communications, wireless and wired, were developed to be point-to-point and working with the same protocols, based on IEEE 1451.0-2007. The tests were made using a microcomputer, which through of browser was possible access the web page stored in the DE2 kit and send commands of control and monitoring to both TIMs (WTIM and STIM). The system describes a different form of development of the NCAP node to be applied in different environments with wired or wireless in the same node. © 2011 IEEE.

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Baccharis dracunculifolia DC (Asteraceae) is the main botanical source used by honeybees to produce Brazilian green propolis whose hepatoprotective properties have been already described. In this work we investigated the protective effects of the glycolic extract of B. dracunculifolia (GEBd) against oxidative stress in isolated rat liver mitochondria (RLM). The GEBd was prepared by fractionated percolation using propylene glycol as solvent. The total phenols and flavonoids, which are substances with recognized antioxidant action, were quantified in GEBd and the phytochemical analysis was carried out by HPLC. GEBd exhibited significant scavenger activity towards DPPH radicals and superoxide anions in a concentration-dependent manner, and also a Fe 2+ chelating activity. GEBd decreased the basal H 2O 2 generation and the Fe 2+- or t-BuOOH-induced ROS production in isolated mitochondria. Lipid oxidation of mitochondrial membranes, protein thiol groups and GSH oxidation were also prevented by GEBd. This shows that B. dracunculifolia exhibit potent antioxidant activity protecting liver mitochondria against oxidative damage and such action probably contribute to the antioxidant and hepatoprotective effects of green propolis. © 2011 Elsevier Ltd.

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Objective: To assess the behavior of the immunoexpression of protein p53 in Reinke's edema and laryngeal squamous cell carcinoma. Study design: retrospective. Methods: we recovered the histological paraffin blocks of patients who were subjected to Reinke's edema and laryngeal squamous cell carcinoma surgery in 2000-2011. The paraffin blocks were cut into 3-μm sections; the specimens were prepared in silanized slides (one slide for each paraffin block) and subjected to immunohistochemical reaction according to the Avidin Biotin Peroxidase method. Monoclonal primary anti-p53 antibodies were used at 1:50 dilution. Slides were examined under a light microscope at different magnitudes and results were interpreted based on the degree of brown staining in the nuclei of epithelial cells and in the extent of the fragment by using a semi-quantitative score from 0 to 3. Results: 67 slides of Reinke's edema and 60 slides of laryngeal squamous cell carcinoma were included. Scores 2 and 3 for staining of the nuclei of epithelial cells were recorded for 46 slides of Reinke's edema (68.65%) and for 57 slides of laryngeal squamous cell carcinoma (95%). As to the extent of the fragment, scores 2 and 3 were recorded for 74% slides of Reinke's edema and for 95% slides of carcinomas. Conclusion: the positive immunoexpression for protein p53, positive in 95% carcinomas and 74% Reinke's edemas, makes us aware of the possible preneoplastic condition of the latter lesion. Further studies are needed to identify and reveal the genetic changes that lead to these results. © 2013 Informa Healthcare USA, Inc.

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

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Camoens, the great Portuguese epic, was a Lucan’s reader, although it seems forgotten by some critics. Among the ancient writers who have influenced Camoens’ text, the Latin poet Lucan (AD 65) receives a smaller, but not irrelevant attention. This paper presents some allusions to Lucan in Os Lusíadas of Camoens, specially exploiting a long imitation of Pharsalia, II, 585-595.

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Angioinvasion/angiodestruction has been reported in a small subset of primary cutaneous anaplastic large-cell lymphomas (PCALCL). Recently, PCALCL with angioinvasive features and cytotoxic phenotype has been characterized as a variant associated with good clinical outcomes despite worrisome histopathologic features. We report a case of PCALCL with angioinvasive features and cytotoxic phenotype associated with reparative changes on the wall of medium-sized vessels involved by the neoplasm, including intimal fibroblastic proliferation and luminal obliteration. This vascular pattern, although previously unreported in PCALCL, is in accordance with the indolent behavior observed in this entity and provides a further link with lymphomatoid papulosis type E.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Flavin mononucleotide (FMN) riboswitches are genetic elements, which in many bacteria control genes responsible for biosynthesis and/or transport of riboflavin (rib genes). Cytoplasmic riboflavin is rapidly and almost completely converted to FMN by flavokinases. When cytoplasmic levels of FMN are sufficient (high levels), FMN binding to FMN riboswitches leads to a reduction of rib gene expression. We report here that the protein RibR counteracts the FMN-induced turn-off activities of both FMN riboswitches in Bacillus subtilis, allowing rib gene expression even in the presence of high levels of FMN. The reason for this secondary metabolic control by RibR is to couple sulfur metabolism with riboflavin metabolism.