772 resultados para Leto, Giulio Pomponio.
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Pós-graduação em Engenharia Mecânica - FEIS
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O objetivo deste estudo foi avaliar a resistência à fadiga cíclica de instrumentos rotatórios de níquel-titânio após simulação de uso clinico em canais curvos (curvatura de 40° e raio de 5 mm). Trinta e seis instrumentos, calibre n° 25 conicidade 0,04, foram divididos em três grupos: o Grupo A com um ciclo de uso; Grupo B, três ciclos de uso e grupo C, cinco ciclos de uso. Um cronômetro digital aferiu em segundos o tempo até a fratura do instrumento que, posteriormente, foi convertido em número de ciclos para fratura. Os dados foram analisados por ANOVA e teste de Tukey (p<0,05). O grupo que utilizou o instrumento por cinco ciclos (grupo C) atingiu significativamente menores números de ciclos antes da fratura (média = 197,5 ciclos) quando comparado com os instrumentos utilizados em um ciclo (média = 309,2) e três ciclos (média = 287,5). Os resultados mostraram que o número de uso de instrumentos RaCe para modelar canais curvos afeta negativamente a resistência à fadiga cíclica dos instrumentos após cinco usos.
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Esta dissertação tem como intuito a análise do conteúdo noticioso dos jornais impressos (2009-2010) das cidades paraenses de Santarém e Marabá, que anualmente enfrentam inundações no período do inverno amazônico (de Dezembro a Junho). O objetivo é analisar se há Comunicação de Risco e como o risco é comunicado nos jornais locais no decorrer das etapas da Gestão de Risco. Há efetividade na Comunicação de Risco? Para isso, a metodologia foi pautada na análise do conteúdo, tendo em vista investigar a forma, conteúdo, número e memória midiática do Jornal de Santarém e Baixo Amazonas - JSBA (Santarém) e do Jornal Correio do Tocantins - CT (Marabá), na temporalidade estabelecida. O principal referencial teórico que serviu de base para pesquisa está vinculado aos conceitos de Comunicação de Risco, Análise do Conteúdo e Gestão de Risco, encontrados respectivamente nas obras de Di Giulio (2008), Bardin (2009) e Jungles (2012). Na comparação entre os jornais, observou-se que o JSBA apresentou maior quantidade de publicações e um conteúdo mais informativo do que o JCT, porém, a forma mostrou-se mais consistentes no segundo jornal. Quanto à memória midiática, o Correio do Tocantins apresentou o elemento do “esquecimento midiático”, que caracteriza a ausência de publicações sobre o tema por um longo período, enquanto que o JSBA abordou a temática em quase todos os meses. Logo, constatou-se que em 2009, os jornais faziam a comunicação do risco e não a Comunicação de Risco. Porém, após o evento extremo (inundação) vivido em 2009, no ano posterior, a Comunicação de Risco, que alerta a população antes da ocorrência do desastre, passou a ganhar seus primeiros contornos no Jornal de Santarém e Baixo Amazonas, em detrimento do Jornal Correio do Tocantins, que continuou a apresentar os mesmos resultados.
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Esta obra analisa com profundidade o trabalho do florentino Sandro Botticelli (aproximadamente 1445-1510), um dos mais conhecidos representantes da arte renascentista, autor de afrescos que decoram a Capela Sistina e de ícones da pintura ocidental, como O Nascimento de Vênus e A Primavera. Aqui, Débora Barbam Mendonça toma como ponto de partida a comparação do estudo Clássico e Anticlássico, de Giulio Carlo Argan, sobre a pintura do florentino, com obras de outros teóricos e historiadores. O objetivo é estudar o conceito de graça na pintura de Boticelli e confrontá-lo com os pressupostos teóricos da produção do artista. A autora discute a interpretação de especialistas sobre o Renascimento como período histórico, filosófico e artístico, discorre sobre o legado teórico da pintura humanista e busca o ideal de belo intrínseco à obra de Boticelli. No terceiro capítulo, Mendonça analisa detalhadamente a pintura A Virgem do magnificat como referência para situar Boticelli como artista intelectual do Renascimento e destacar na obra sua ideia de graça. A filósofa conclui que Boticelli seguia uma linha teórica, mas a partir de uma escolha individual, ou seja, desenvolvia uma estética psicológica. E, por meio dos elementos formais de que dispunha, transmitia em suas obras o conceito de graça, transpondo ao mesmo tempo o resultado do diálogo que mantinha com a Filosofia, a ciência, a religião e, nostalgicamente, com a Antiguidade
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A síndrome das unhas frágeis caracteriza-se por fragilidade da lâmina ungueal, acometendo 27% das mulheres. Realizamos estudo transversal com pacientes dermatológicas sobre a percepção de fragilidade ungueal. Avaliamos 138 pacientes com idade mediana de 36,5 anos. Ao exame, 57% apresentavam alterações e 49% relatavam fragilidade ungueal. Os três primeiros dedos das mãos foram os mais acometidos. A onicosquizia associou-se com onicofagia (OR = 3,29), trabalhos domésticos (OR = 2,95) e contato com água (OR = 2,44). A onicorrexe teve a mais forte associação com a percepção de fragilidade ungueal (OR = 17,89). A fragilidade foi mais percebida em negras, pardas e atópicas e associou-se com humor depressivo.
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An epidemiological survey for the monitoring of bovine tuberculosis transmission was carried out in western Liguria, a region in northern Italy. Fifteen Mycobacterium bovis strains were isolated from 63 wild boar samples (62 from mandibular lymph nodes and 1 from a liver specimen). Sixteen mediastinal lymph nodes of 16 head of cattle were collected, and 15 Mycobacterium bovis strains were subsequently cultured. All M. bovisstrains isolated from cattle and wild boars were genotyped by spoligotyping and by restriction fragment length polymorphism (RFLP) analysis with the IS6110 and IS1081 probes. All M. bovis strains showed the typical spoligotype characterized by the absence of the 39 to 43 spacers in comparison with the number in M. tuberculosis. A total of nine different clusters were identified by spoligotyping. The largest cluster included 9 strains isolated from wild boars and 11 strains isolated from cattle, thus confirming the possibility of transmission between the two animal species. Fingerprinting by RFLP analysis with the IS6110 probe showed an identical single-band pattern for 29 of 30 strains analyzed, and only 1 strain presented a five-band pattern. The use of IS1081 as a second probe was useful for differentiation of M. bovis from M. bovis BCG but not for differentiation among M. bovis strains, which presented the same undifferentiated genomic profile. In relation to the epidemiological investigation, we hypothesized that the feeding in pastures contaminated by cattle discharges could represent the most probable route of transmission of M. bovis between the two animal species. In conclusion, our results confirmed the higher discriminatory power of spoligotyping in relation to that of RFLP analysis for the differentiation of M. bovis genomic profiles. Our data showed the presence of a common M. bovis genotype in both cattle and wild boars, confirming the possible interspecies transmission of M. bovis.
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Observations of cosmic rays arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three method can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ... , 110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.
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Pompe disease is a genetic disorder resulting from a deficiency of lysosomal acid alpha-glucosidase (GAA) that manifests as a clinical spectrum with regard to symptom severity and rate of progression. In this study, we used microarrays to examine gene expression from the muscle of two cohorts of infantile-onset Pompe patients to identify transcriptional differences that may contribute to the disease phenotype. We found strong similarities among the gene expression profiles generated from biceps and quadriceps, and identified a number of signaling pathways altered in both cohorts. We also found that infantile-onset Pompe patient muscle had a gene expression pattern characteristic of immature or regenerating muscle, and exhibited many transcriptional markers of inflammation, despite having few overt signs of inflammatory infiltrate. Further, we identified genes exhibiting correlation between expression at baseline and response to therapy. This combined dataset can serve as a foundation for biological discovery and biomarker development to improve the treatment of Pompe disease. (C) 2012 Elsevier Inc. All rights reserved.
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Introduction: The aim of the present study was to evaluate the physicochemical properties of a bioceramic root canal sealer, Endosequence BC Sealer. Radiopacity, pH, release of calcium ions (Ca2+), and flow were analyzed, and the results were compared with AH Plus cement. Methods: Radiopacity and flow were evaluated according to ISO 6876/2001 standards. For the radiopacity analysis, metallic rings with 10-mm diameter and 1-mm thickness were filled with cements. The radiopacity value was determined according to radiographic density (mm Al). The flow test was performed with 0.05 mL of cement placed on a glass plate. A 120-g weight was carefully placed over the cement. The largest and smallest diameters of the disks formed were measured by using a digital caliper. The release of Ca2+ and pH were measured at periods of 3, 24, 72, 168, and 240 hours with spectrophotometer and pH meter, respectively. Data were analyzed by analysis of variance and Tukey test (P < .05). Results: The bioceramic endodontic cement showed radiopacity (3.84 mm Al) significantly lower than that of AH Plus (6.90 mm Al). The pH analysis showed that Endosequence BC Sealer showed pH and release of Ca2+ greater than those of AH Plus (P < .05) during the experimental periods. The flow test revealed that BC Sealer and AH Plus presented flow of 26.96 mm and 21.17 mm, respectively (P < .05). Conclusions: Endosequence BC Sealer showed radiopacity and flow according to ISO 6876/2001 recommendations. The other physicochemical properties analyzed demonstrated favorable values for a root canal sealer. (J Endod 2012;38:842-845)
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Background Tumor markers are genes or their products expressed exclusively or preferentially in tumor cells and cancer-testis antigens (CTAs) form a group of genes with a typical expression pattern expressed in a variety of malignant neoplasms. CTAs are considered potential targets for cancer vaccines. It is possible that the CTA MAGE-A4 (melanoma antigen) and MAGE-C1 are expressed in carcinoma of the oral cavity and are related with survival. Methods This study involved immunohistochemical analysis of 23 patients with oral squamous cell carcinoma (SCC) and was carried out using antibodies for MAGE-A4 and MAGE-C1. Fisher's exact test and log-rank test were used to evaluate the results. Results The expression of the MAGE-A4 and MAGE-C1 were 56.5% and 47.8% without statistical difference in studied variables and survival. Conclusion The expression of at least 1 CTA was present in 78.3% of the patients, however, without correlation with clinicopathologic variables and survival. (c) 2011 Wiley Periodicals, Inc. Head Neck, 2012
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Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown. (C) 2012 Elsevier B.V. All rights reserved.
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The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.
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The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or "rapid") monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction.
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The aim of this study was to assess, in vivo, the accuracy of the NovApex (R) electronic foramen locator in determining working length (WL) in vital and necrotic posterior teeth. The NovApex (R) was used in 144 canals: 35 teeth with vital pulps (68 canals) and 42 teeth with necrotic pulps (76 canals). WL was measured with the NovApex (R) locator and confirmed using the radiographic method. Differences between electronic and radiographic measurements ranging between 0.0 and 0.4 millimeters were classified as acceptable; differences equal to or greater than 0.5 millimeter were considered unacceptable. Pearson's chi-square test was used to assess the influence of pulp condition on the accuracy of NovApex (R) (alpha = 0.05). Regardless of pulp condition, differences between electronic and radiographic WL measurements were acceptable in 73.61% of the canals. No statistically significant differences in accuracy were observed when comparing vital and necrotic canals (p > 0.05). There were 38 unacceptable measurements. In none of these cases was the file tip located beyond the radiographic apex; in 32, it was located short of the NovApex (R) measurement. Pulp condition had no significant effect on the accuracy of NovApex (R).
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The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E-nu between 10(17) eV and 10(20) eV from point-like sources across the sky south of +55 degrees and north of -65 degrees declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of similar to 3.5 years of a full surface detector array for the Earth-skimming channel and similar to 2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k(PS) . E-nu(-2). from a point-like source, 90% confidence level upper limits for k(PS) at the level of approximate to 5x10(-7) and 2.5x10(-6) GeV cm(-2) s(-1) have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively.