Oscilações térmicas do nervo facial in vitro em mastoidectomias descompressivas

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2013.Introdução: Há diversas situações médicas que exigem a descompressão aguda do nervo facial (NF), inclusive lesões traumáticas ou neoplásicas. No entanto, o NF é altamente vulnerável às oscilações térmicas e/ou mecânicas, as quais podem vir a ocorrer durante procedimentos cirúrgicos que requerem a utilização de brocas. Objetivos: Avaliar possíveis lesões térmicas ocasionadas por brocas de alta e baixa rotação, bem como comparar suas peculiaridades durante a mastoidectomia radical para descompressão do NF. Método: Oito espécimes de osso temporal obtidos de cadáveres foram submetidos à descompressão do NF pela técnica de mastoidectomia radical, usando brocas de alta rotação e baixa rotação, com irrigação contínua ou sob demanda. As oscilações de temperatura transoperatórias foram medidas através de sensores térmicos ligados ao osso temporal. Estes sensores seguiam o trajeto do NF, à distâncias de 10, 5 e 2mm, utilizando-se ponteiras cortantes de 2,4 milímetros ou ponteiras rombas diamantadas de 2,1mm. Resultados: O uso de brocas de alta velocidade com irrigação sob demanda provocou uma oscilação significativa de temperatura no NF quando comparadas às brocas de baixa velocidade sob irrigação contínua (p < 0,05). As temperaturas mais elevadas foram diretamente proporcionais a suas distâncias do NF. No entanto, nenhuma das brocas apresentou níveis de temperaturas altas o suficiente para causar dano ao NF. Conclusões: As oscilações térmicas secundárias ao uso de brocas em mastoidectomias radicais são consideradas um fator de risco potencial ao NF. Porém, as brocas de alta e de baixa velocidade atualmente disponíveis, sob condições adequadas, usando irrigação contínua e à uma distância limitada do NF, mostraram oscilações térmicas transoperatórias seguras. ______________________________________________________________________________________ ABSTRACTIntroduction: There are many medical situations that demand facial nerve decompression, including traumatic or neoplastic lesions. However, the facial nerve is highly vulnerable to thermal oscillations, which can be observed during surgical procedures that demand the use of drills. Objectives: To assess potential thermal injuries caused by drills of high and low speed, and compare their peculiarities during radical mastoidectomy for facial nerve decompression. Methods: Eight temporal bone flaps obtained from cadavers were submitted to facial nerve decompression by the radical mastoidectomy technique, using both high- and low-speed drills with continuous irrigation or irrigation on demand. The temperature oscillations during all of the procedures were measured using thermal sensors attached to the temporal bone, following the path of the facial nerve, at distances of 10, 5, and 2mm, using cutting burrs of 2.4mm or diamond ball burrs of 2.1mm. Results: High-speed drilling with irrigation on demand generated a higher temperature rise in the facial nerve when compared to low-speed drilling under continuous irrigation (p < 0.05). The closer the burrs were to the facial nerves, the higher the temperatures measured. Neither the high-powered drill nor the low-powered drill presented levels of temperatures high enough to cause facial nerve damage. Conclusions: Thermal oscillations secondary to the use of drills in radical mastoidectomies should be considered a potential risk factor in surgical procedures for facial nerve decompression. However, the recently developed disposable devices, high- or lowpowered drills were safely used in these procedures under adequate conditions, by using continuous irrigation and a limited distance from the facial nerve

The entropy of elliptical galaxies in Coma: a clue for a distance indicator

We have fitted the surface brightness of a sample of 79 elliptical galaxies pertaining to the Coma cluster of galaxies using the Sersic profile. This model is defined through three primary parameters: scale length (a), intensity (\Sigma_0), and a shape parameter (\nu); physical and astrophysical quantities may be computed from these parameters. We show that correlations are stronger among primary parameters than the classical astrophysical ones. In particular, the galaxies follow a high correlation in \nu and a parameters. We show that the \nu and a correlation satisfies a constant specific entropy condition. We propose to use this entropy relation as distance indicator for clusters.Comment: 5 pages, 3 figures, submitted to MNRAS Letter

The Use of Photogrammetry as a Means of Digital Reconstruction and Preservation of Fragmented Human Remains

UIDB/04038/2020 UIDP/04038/2020publishersversionpublishe

The Use of Photogrammetry to Explore Complex Burials in Archaeological Contexts

UIDB/04038/2020 UIDP/04038/2020publishersversionpublishe

On the tilt of Fundamental Plane by Clausius' virial maximum theory

The theory of the Clausius' virial maximum to explain the Fundamental Plane (FP) proposed by Secco (2000, 2001,2005) is based on the existence of a maximum in the Clausius' Virial (CV) potential energy of a early type galaxy (ETG) stellar component when it is completely embedded inside a dark matter (DM) halo. At the first order approximation the theory was developed by modeling the two-components with two cored power-law density profiles. An higher level of approximation is now taken into account by developing the same theory when the stellar component is modeled by a King-model with a cut-off. Even if the DM halo density remains a cored power law the inner component is now more realistic for the ETGs. The new formulation allows us to understand more deeply what is the dynamical reason of the FP tilt and in general how the CV theory may really be the engine to produce the FP main features. The degeneracy of FP in respect to the initial density perturbation spectrum may be now full understood in a CDM cosmological scenario. A possible way to compare the FPs predicted by the theory with those obtained by observations is also exemplified.Comment: 35 pages, 8 figure

On Mechanics and Thermodynamics of a stellar galaxy in a two-component virial system and the Fundamental Plane

The paper confirms the existence of a special configuration (among the infinite number of virial states) which a B stellar(Baryonic) component may assume inside a given D dark halo potential well.This satisfies the d'Alembert Principle of virtual works and its typical dimension works as a scale length (tidal radius)induced on the gravitational field of the bright component by the dark one.Its dynamic and thermodynamic properties are here analyzed in connection with the physical reason for the existence of the Fundamental Plane (FP) for ellipticals.The analysis is performed by using 2-component models with two power-law density profiles and two homogeneous cores and compared with some observable scaling relations for pressure supported ellipticals.The virial equilibrium stages of the 2-component system have to occur after a previous violent relaxation phase. If the stellar B component is allowed to cool slowly its virial evolution consists of a sequence of contractions with enough time to rearrange the virial equilibrium after any step. The thermodynamic process during the dynamical evolution is so divided into a sequence of transformations which are irreversible but occur between two quasi-equilibrium stages.The analysis allows the conclusion that the induced scale length is a real confinement for the stellar system. The presence of this specific border on the space of the baryonic luminous component has to be regarded as the physical reason why a stellar galaxy belongs to the FP and why astrophysical objects, with a completely different history and formation, but characterized by a tidal radius (as the globular clusters are) lie on the same FP. An other problem addressed is how this special configuration may be reached and why an elliptical is not completely relaxed in respect to its dark halo.Comment: 42 pages, 7 figures, in press in New Astronomy 200

Uso excessivo de dispositivos eletrônicos em meio a pandemia Sars-Cov-2 durante o seu confinamento e suas consequências refracionais: revisão de literatura

A miopia é caracterizada por um erro refracional no qual a imagem do objeto se forma antes da retina¹. Atualmente, o uso de telas, tem sido considerado como o principal agente no desenvolvimento da miopia². O objetivo do estudo é analisar os erros refrativos durante o confinamento pela SARS-CoV-2. Metodologia: Trata-se de uma revisão bibliográfica utilizando PubMed, sciELO, academic Google e Medline. Discussões: A correlação entre o uso de telas e a miopia ressaltam que quanto maior a utilização, maior a incidência de miopia enquanto exposição ao ar livre e a prática de atividades físicas são fatores de proteção. Considerações finais: A pesquisa demonstrou uma associação frequente entre miopia e o uso de telas, pois o aumento destas foram significativas durante a pandemia

Os atuais tratamentos de endometriose com suplementação hormonal de anticoncepcional: uma mini revisão de literatura

A endometriose é uma patologia relacionada com o local do endométrio que possui efetivos tratamentos com o uso de anticoncepcional oral. O objetivo desse artigo é discutir a eficaz dessa suplementação hormonal nos sintomas dessa doença. O texto a seguir utilizou 5 artigos pesquisados no site BVS e PUBMED. Baseando-se nestes artigos foi discorrido sobre o afeto dos sintomas na rotina da paciente e as vantagens do tratamento com uso de anticoncepcionais, e também sobre outros que são efetivos. Assim, a conclusão afirma sobre a diminuição dos sintomas, com destaque para a dor pélvica, após o uso de contraceptivos, porém, deve-se ter outros estudos sobre endometriose já que acomete 176 milhões de mulheres pelo mundo.&nbsp