905 resultados para SMA wire actuator
Resumo:
Ao criar a técnica para tratamento ortodôntico denominado Straight-Wire, Andrews introduziu o uso de bráquetes pré-programados, ou bráquetes construídos individualmente para cada dente, com o objetivo de melhor posicioná-los ao final do tratamento. Capelozza Filho sugeriu novas angulações e inclinações para dentes que necessitavam de ajuste ao final do tratamento, criando prescrições para os diferentes padrões faciais. O presente trabalho tem por objetivo avaliar as alterações nas inclinações dentárias causadas pelo tratamento ortodôntico nos dentes anteriores utilizando-se da prescrição Capelozza Classe II. Foram selecionados 17 indivíduos adultos de padrão facial II, portadores de má-oclusão Classe II; para tratamento ortodôntico compensatório, e em três tempos clínicos, relativos a três diferentes fios ortodônticos (.020 ; .019 x .025 , .021 x .025 ), foram realizados exames de tomografia computadorizada volumétrica, para mensuração e posterior avaliação das inclinações dentárias alcançadas em cada um dos tempos, pela ação de cada um dos fios, comparando-se estes valores aos da prescrição utilizada, bem como das diferenças ocorridas entre os tempos. Após a coleta de dados e aplicação dos testes estatísticos, concluiu-se que existe diferença estatística (p<0,05) na maioria dos valores da prescrição e os valores encontrados em cada um dos tempos avaliados; não foram encontradas diferenças estatisticamente significantes quando comparados os tempos estudados. Observou-se também uma tendência dos dentes a expressarem a prescrição apenas em T3.
Resumo:
Although transforming growth factor beta (TGF-beta) superfamily ligands play critical roles in diverse developmental processes, how cells transduce signals from these ligands is still poorly understood. Cell surface receptors for these ligands have been identified, but their cytoplasmic targets are unknown. We have identified three Caenorhabditis elegans genes, sma-2, sma-3, and sma-4, that have mutant phenotypes similar to those of the TGF-beta-like receptor gene daf-4, indicating that they are required for daf-4-mediated developmental processes. We show that sma-2 functions in the same cells as daf-4, consistent with a role in transducing signals from the receptor. These three genes define a protein family, the dwarfins, that includes the Mad gene product, which participates in the decapentaplegic TGF-beta-like pathway in Drosophila [Sekelsky, J. J., Newfeld, S. J., Raftery, L. A., Chartoff, E. H. & Gelbart, W. M. (1995) Genetics 139, 1347-1358]. The identification of homologous components of these pathways in distantly related organisms suggests that dwarfins may be universally required for TGF-beta-like signal transduction. In fact, we have isolated highly conserved dwarfins from vertebrates, indicating that these components are not idiosyncratic to invertebrates. These analyses suggest that dwarfins are conserved cytoplasmic signal transducers.
Resumo:
After the Japanese attack at Pearl Harbor on December 7, 1941, approximately 120,000 people of Japanese ancestry living on the west coast of the United States were forcibly removed from their home communities. These people were designated as "evacuees" by the U.S. Government and were incarcerated within a network of federal government facilities the largest of which were internment centers operated by the War Relocation Authority that held mostly U.S. citizens. The Granada Relocation Center (Amache) was the smallest of these internment centers. The presence of saké at Amache indicates that Japanese Americans continued important practices of daily life despite restrictions under confinement. This thesis investigates the practices of saké production and consumption at Amache and examines the importance of these practices in Japanese American daily life. In order to understand these practices, this research draws on multiple lines of evidence. This includes investigations of an assemblage of the material culture associated with saké, research into the history and methods of production and consumption, collection of oral histories, review of archival data, and the application of practice theory. These data provide insight into practices that are not well understood by researchers of Japanese American internment due to their illicit nature. This research endeavors to characterize how saké was produced and used at Amache and provides a way to understand how cultural practices maintain aspects of everyday life in ways that may have little to do with intentional resistance.
Resumo:
Recent progress is emerging on nondiffracting subwavelength fields propagating in complex plasmonic nanostructures. In this paper, we present a thorough discussion on diffraction-free localized solutions of Maxwell’s equations in a periodic structure composed of nanowires. This self-focusing mechanism differs from others previously reported, which lie on regimes with ultraflat spatial dispersion. By means of the Maxwell–Garnett model, we provide a general analytical expression of the electromagnetic fields that can propagate along the direction of the cylinder’s axis, keeping its transverse waveform unaltered. Numerical simulations based on the finite element method support our analytical approach. In particular, moderate filling fractions of the metallic composite lead to nonresonant-plasmonic spots of light propagating with a size that remains far below the limit of diffraction.