Forámenes Nutricios en los Huesos Largos de los Miembros
SUMMARY:The major blood supply to long bones occurs through the nutrient arteries, which enter through the nutrient foramina. This supply is essential during the growing period, during the early phases of ossification, and in procedures such as bone grafts, tumor resections, traumas, congenital pseudoarthrosis, and in transplant techniques in orthopedics. The present study analyzed the location and the number of nutrient foramina in the diaphysis of 885 long bones of the upper and lower limbs of adults: 174 humeri, 157 radii, 146 ulnae, 152 femora, 142 tibiae and 114 fibulae. The location of the nutrient foramina is predominant on the anterior aspect of the upper limb long bones, and on the posterior aspect of the lower limb long bones. The majority of the bones studied had a single nutrient foramen, which may represent a single source of blood supply. The mean foraminal index for the upper limb bones was 55.2% for the humerus, 35.7% for the radius, and 37.9% for the ulna, and for the lower limb bones, 43.7% for the femur, 32.7% for the tibia and 46.1% for the fibula. This study recorded data related to the population of Southern Brazil, providing ethnic data to be used for comparison and that may help in surgical procedures and in the interpretation of radiological images.
We assessed litterfall and nutrient cycling in an old-growth Atlantic rainforest in southern Brazil. Plant litter collected monthly was separated into: leaves, twigs, reproductive organs, and fragments, and dried, weighed, and ground. Determination of carbon, nitrogen, phosphorus, potassium, calcium, magnesium, and sodium contents of different litter fractions was also performed. The total deposition was 8.44 Mg -1 ha -1 year -1 , with a higher proportion of leaves fraction. Litterfall predominated in spring and summer, coinciding with the highest average temperature and rainfall in the study area. For leaves, twigs and fragments, the elements sequence of concentration was C>N>Ca>K>Mg>P>Na; whereas for reproductive organs it was C>N>K>Ca>Mg>P>Na. A higher concentration of nutrients was observed in spring and summer for the leaves fraction. The quantitative transfer of nutrients by litterfall fractions to the forest soil followed the same sequence observed for the concentration of nutrients.
No Brasil há 10 espécies de Akodon Meyen, 1833 e a maioria apresenta algum grau de sobreposição geográfica havendo inclusive registros de simpatia. A identificação das espécies é difícil e pode ser feita pela análise da estrutura morfológica de pelos. Assim, para a identificação da microestrutura de pelos de nove espécies brasileiras de Akodon, foram utilizados pelos-guardas primários de amostras de coleções zoológicas. Foi adotado o método de análise das escamas cuticulares e da medula. O padrão de cutícula para todas as espécies foi folidáceo estreito. Já para a medula foram reconhecidos três padrões básicos como multisseriada alveolar, multisseriada listrada e misto de alveolar e listrada. Akodon cursor é a única espécie com predomínio de quatro fileiras sendo que exemplares 2n = 14 e 2n = 15 apresentam medula alveolar e o 2n = 16, medula listrada e células longilíneas. Para Akodon paranaensis e A. lindberghi a medula se alterna entre três e quatro fileiras. As demais espécies apresentam três fileiras. Akodon mystax apresenta um maior espaçamento entre as células. Akodon reigi possui o setor intermediário com fileiras ovaladas e bem ligadas e Akodon toba tem as células da fileira central variando com uma e duas células alveolares pequenas. No padrão listrado, Akodon montensis apresenta espaço intercelular mais estreito em relação à espessura da célula. No padrão misto, Akodon azarae apresenta células com contorno evidente, já Akodon serrensis as células apresentam formato irregular. Assim, o uso da microestrutura dos pelos como ferramenta para a identificação das espécies de Akodon mostrou-se perfeitamente viável.
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