RESUMO
Stable isotope ratios of C and N in the bone tissue of three different skeletal elements (angular, cleithrum and vertebra) of three fish species from different evolutionary lineages (Clupeiformes, Atheriniformes and Notothenioidei) were determined before (δ13 Cbulk and δ15 Nbulk ) and after demineralization and delipidation (δ13 Cdml and δ15 Ndml ). One of the species had cellular bone and the other two had acellular bone. Results revealed that δ15 N and δ13 C values from different skeletal elements were interchangeable in species with acellular bone, but caution was needed in species with cellular bone, as δ15 N values varied among skeletal elements. Furthermore, δ15 Nbulk values were significantly lower than δ15 Ndml values in the three species, thus suggesting that they are not comparable. This difference is probably because δ15 Nbulk refers to total bone protein and δ15 Ndml to collagen only.
Assuntos
Osso e Ossos/química , Peixes , Animais , Técnica de Desmineralização Óssea , Isótopos de Carbono/análise , Lipídeos/isolamento & purificação , Isótopos de Nitrogênio/análise , Perciformes , Alimentos MarinhosRESUMO
In this study, stress of traumatized incisor and the effect of stress on tooth and alveolar bone was studied with two-dimensional photoelasticity. Two homogeneous two-dimensional maxillary central incisor models were prepared. Loads were applied to the labial side of incisal edge and middle third of the crown at angles of 45 degrees and 90 degrees. It was observed that stress was increased on teeth and alveolar bone when load was applied 90 degrees on labial side of incisal edge.
Assuntos
Análise do Estresse Dentário , Incisivo/lesões , Traumatismos Dentários/fisiopatologia , Processo Alveolar/fisiopatologia , Birrefringência , Análise do Estresse Dentário/métodos , Elasticidade , Humanos , Maxila , Estresse Mecânico , Coroa do Dente/lesões , Raiz Dentária/fisiopatologiaRESUMO
O autor descreve os varios tempos de uma extracao extracapsular de catarata seguida de implante de lente de camara posterior modelo Sinskey.Descreve alguns instrumentos, desenhados por ele, com os quais tem alcancado bons resultados nesta cirurgia, como alca de Snellen com dupla perfuracao em sua parte anterior e superior e 2 canulas de via dupla, uma reta e outra curva, com as quais remove a cortex residual apos a extracao do nucleo