67 research outputs found

    Comparação de limas ProFile GT Série X com ProFile GT através da caracterização por DRX e de um Estudo por Elementos Finitos

    Get PDF
    The emergence of NiTi alloys and the development of their properties, namely superelasticity, motivated the inclusion of such materials in files used in the clinical practice of Endodontics. These files present several advantages when compared to Stainless Steel files (still widely used today), especially their larger flexibility, whereby the improvement of these alloys over the last few years has deserved a growing attention by both the medical industry and medical community. Flexibility in endodontic files is paramount for the preparation of anatomically complex root canals, since it preserves the dental structure, limits the apical transport, reduces the risk of iatrogenic mistakes and allows the irrigant to flow and reach the apical foramen. Flexibility in NiTi files due to their superelastic behaviour mainly dependends not only on the crystallographic phases present in the alloy and the thermal, mechanical and chemical treatments to which the alloy has been subjected but also due to files’ geometry. Recently, the market has seen introduced the M-Wire, a NiTi alloy used in GTX files that, according to its manufacturer, has been treated in order to have a larger flexibility at body temperature than files built with conventional NiTi wire, for instance the one used in GT files. This study aims at contributing to the better understanding of the mechanisms behind the properties each kind of file presents and to find out supporting grounds that substantiate the manufacturer pretension, through the metallurgic characterization of GT and GTX files by X-Ray Diffraction (XRD) and through finite element models of the files under bending. Some experimental results are presented and discussed, being shown that, at body temperature, the GTX files accuse the presence of R Phase, contrary to the GT files, being their geometry very alike; as such, they are expected to be more flexible and clinically superior

    Outcomes for patients referred to a head and neck cancer center

    Get PDF
    Os tumores da cabeça e pescoço (TCP) associam-se a elevada morbilidade e mortalidade. A referenciação atempada assume particular importância na evolução clínica. No intuito de avaliar a evolução dos doentes observados em consulta de Otorrinolaringologia “Oncológica”, procedeu-se a um estudo dos doentes com TCP referenciados ao Instituto Português de Oncologia (IPO) de Lisboa no ano 2008. Dos 454 doentes observados, a maioria era do sexo masculino (86%) com idade média 60 anos. Os tumores mais comuns foram laríngeos (36%), a maioria (69%) em estadio avançado. A cirurgia foi o tratamento primário em 60%. O intervalo médio de tempo entre primeira consulta e tratamento foi 75 dias, e a sobrevida global aos 2 anos 66%. A maioria dos doentes apresentava tumores avançados aquando da referenciação, o que comprometeu a sobrevida e o controlo locorregional, apesar do início rápido dos tratamentos. Políticas de saúde pública deveriam ser implementadas para melhoria da educação para a saúde, prevenção e referenciação destes doentes.Head and neck cancer is related to high morbidity and mortality. Early referral is particularly important. We performed a retrospective study concerning all patients referred to the head and neck consultation of Lisbon’s Instituto Português Oncologia over the year of 2008. Most of the 454 patients observed were male (86%), with a mean age of 60 years. The most common cancer was laryngeal (36%), and most of the tumors (69%) were advanced. Surgery and adjuvant radiotherapy were used in 60% of patients. The average time elapsed between first appointment and treatment was 75 days. The overall 2-year survival rate was 66%. Most of our patients had advanced tumors at the time of referral. Despite the early beginning of treatment at our center, survival, loco-regional control and treatment options are compromised. Public health policies should be developed to improve public health education regarding head and neck cancer prevention and early referral

    Preliminary morpho-agronomic characterization of cumari hot peppers

    Get PDF
    A pimenta cumari, Capsicum baccatum var. praetermissum e C. baccatum var. baccatum, é uma espécie semidomesticada, endêmica das regiões Sudeste e Centro-Oeste do país. Apesar da sua importância econômica, principalmente para a agricultura familiar, e da sua ampla variabilidade, ainda não existe uma cultivar dessa espécie disponível no mercado brasileiro. Este trabalho teve como objetivo avaliar acessos de pimenta cumari do Banco de Germoplasma de Capsicum da Embrapa Hortaliças com base em características morfoagronômicas e identificar acessos promissores que possam dar origem a um programa de melhoramento genético. Verificou-se a existência de grande variabilidade entre os acessos analisados, tendo sido encontradas diferenças para a maioria das variáveis. O material mais precoce, CNPH 4065, floresceu aos 81 dias após a semeadura e o mais tardio, CNPH 2957, aos 126 dias. O número de flores por axila variou de 1 a 3. Já em relação à pilosidade, a quantidade de plantas muito pilosas foi de 6,25%; pilosidade moderada 6,25%; pouca pilosidade 12,50% e sem pilosidade 75,00%. A estimativa da produtividade variou de 8 a 340 gramas por planta e a incidência de viroses indicou o PepYMV como o mais frequente, tendo sido encontrado em 33% das plantas analisadas. Os acessos CNPH 4065, CNPH 3824, CNPH 3993, CNPH 2964 e CNPH 2948 foram considerados promissores para o uso em programa de melhoramento.The cumari hot pepper, Capsicum baccatum var. praetermissum and C. baccatum var. baccatum, is a semi-domesticated species, endemic to the Southeast and Midwest regions of Brazil. Despite its economic importance, especially for small farmers in family agriculture systems, no cumari cultivars are available in the Brazilian market. This research aimed to evaluate 16 cumari accessions of the Capsicum Germplasm Bank of Embrapa Vegetables based on morpho-agronomic features, and identify promising accessions for further breeding programs. Genetic variability was found among accessions and differences were observed for the majority of the characteristics. The earliest genotype, CNPH 4065, set flowers 81 days after sowing and the latest, CNPH 2957, at 126 days. The number of flowers per axil ranged from 1 to 3. Pubescence, a relevant plant characteristic associated to insect resistance was found as follows: highly pubescent plants 6.25%; moderately pubescent 6.25%; almost glabrous 12.50%; and glabrous 75.00%. Yield was estimated in between 8 grams/plant and 340 grams/plant. PepYMV (33% of the total number of plants) was the most prevalent virus infecting cumari hot peppers in the field. Five accessions (CNPH 4065; CNPH 3824; CNPH 3993; CNPH 2964; CNPH 2948) were considered as promising to be used in cumari breeding programs

    Genetic variability in conilon coffee related to grain attributes in an irrigated crop in the Cerrado.

    Get PDF
    The objective of this work was to quantify the genetic variability of 213 conilon coffee accessions of the Robusta Tropical cultivar, based on chemical characteristics related to the quality of green coffee beans, as well as to identify promising accessions for the breeding program of irrigated conilon coffee in the Brazilian Cerrado. The chemical characteristics evaluated were: protein and caffeine contents, total soluble solids and total lipids, ether extract, pH, and total titratable acidity. The data were subjected to the principal component analysis and cluster analysis based on the similarities observed within the first two principal components using the minimum variance method (Wards) and, as a measure of similarity, the Euclidean distance. The three main components explained 72.64% of the total variation of the data. All characteristics, except pH, were correlated with the first three components. It was possible to separate the genotypes in three clusters, according to the similarities observed in the behavior of the variables. The evaluated accessions present genetic variability regarding the assessed quality characteristics of green coffee beans, and CPAC 160 and CPAC 32 are the most promising for the breeding program of conilon coffee for cultivation under irrigation in the Cerrado.Título em português: Variabilidade genética em café conilon relativa aos atributos dos grãos em cultivo irrigado no Cerrado

    Estimativa de parâmetros genéticos, correlações fenotípicas e ambientais no girassol do cerrado do Distrito Federal.

    Get PDF
    RESUMO: O propósito deste trabalho foi avaliar a estima - tiva de parâmetros genéticos, correlações fe - notipicas e ambientais no girassol do Cerrado do Distrito Federal. Os caracteres analisados foram: rendimento de grãos, tamanho do ca - pítulo, peso de mil aquênios, altura de plantas e dias para floração inicial. Foram constatadas diferenças altamente significativas entre os ge - nótipos para todas as características morfoa - gronômicas avaliadas. Para o coeficiente CVr a maioria dos valores foram superior a 1 nos dois anos considerados, indicando que para a maioria dos caracteres aferidos há a possibi - lidade de êxito na seleção fenotípica uma vez que a variância genética superou a ambiental. Na herdabilidade, a maior estimativa verifica - da foi para o caráter PMA (98,76%) em 2013 e para DFI (99,68%) em 2014. Foram cons - tatadas diferenças altamente significativas en - tre os genótipos para todas as características morfoagronômicas avaliadas. O alto coeficiente de variação genético destaca a possibilidade de obter ganhos genéticos para todas as caracte - rísticas analisadas salvo em tamanho de capi - tulo. Materiais genéticos com potencial para as características agronômicas pesquisadas foram identificados no trabalho, podem ser indicadas ao sistema de produção irrigado no Cerrado. abstract: The purpose of this study was to estimate ge - netic parameters, phenotypic and environmen - tal correlations in sunflower of Brazilian savan - nah. The characters analyzed were: grain yield, chapter length, weight of a thousand achenes, plant height and days to start flowering. Hi - ghly significant differences were observed among genotypes for all morphoagronomic cha - racteristics evaluated. For the most CVr coe - fficient values were higher than 1 in the two years under consideration, indicating that for the majority of measured characters there is the possibility of successful phenotypic selection once the genetic variance exceeded the envi - ronmental. The heritability estimate was the hi - ghest for the PMA character (98,76%) in 2013 and DFI (99,68%) in 2014. Highly significant differences were observed among genotypes for all morphoagronomic characteristics evalu - ated. The high coefficient of genetic variation show the possibility of obtaining genetic gain for all examined characteristics except in chap - ter length. Genetic material with potential for the researched agronomic characteristics were identified in the work, can be indicated to the irrigated production system in the Brazilian sa - vannah
    corecore