RESUMO
We investigate the magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process through the calorimetric method. Specifically, we propose a theoretical approach to magnetic hyperthermia from a thermodynamic point of view. To test the robustness of the approach, we perform hyperthermia experiments and analyse the thermal behavior of magnetite and magnesium ferrite magnetic nanoparticles dispersed in water submitted to an alternating magnetic field. From our findings, besides estimating the specific loss power value from a non-adiabatic and radiating process, thus enhancing the accuracy in the determination of this quantity, we provide physical meaning to a parameter found in literature that still remained not fully understood, the effective thermal conductance, and bring to light how it can be obtained from experiment. In addition, we show our approach brings a correction to the estimated experimental results for specific loss power and effective thermal conductance, thus demonstrating the importance of the heat loss rate due to the thermal radiation in magnetic hyperthermia.
RESUMO
Accumulated sludge in polishing (maturation) ponds reduces the hydraulic retention time (smaller useful volume), and this could potentially lead to a decrease in performance. However, settled biomass, present in the sediments, can contribute to nitrogen removal by different mechanisms such as nitrification and denitrification. This study investigated the influence of the bottom sludge present in a shallow maturation pond treating the effluent from an anaerobic reactor on the nitrification and denitrification processes. Nitrification and denitrification rates were determined in sediment cores by applying ammonia pulses. Environmental conditions in the medium were measured and bacteria detected and quantified by real-time polymerase chain reaction (real-time PCR). The pond showed daily cycles of mixing and stratification and most of the bacteria involved in nitrogen removal decreased in concentration from the upper to the lower part of the sludge layer. The results indicate that denitrifiers, nitrifiers and anammox bacteria coexisted in the sludge, and thus different metabolic pathways were involved in ammonium removal in the system. Therefore, the sediment contributed to nitrogen removal, even with a decrease in the hydraulic retention time in the pond due to the volume occupied by the sludge.
Assuntos
Nitrogênio/análise , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Reatores Biológicos , Brasil , Desnitrificação , LagoasRESUMO
We revised 16 patients submitted to epilepsy surgery using a new method of digital, real-time, portable electrocorticography. Patients were operated upon over a period of 28 months. There were no complications. The exam was useful in 13 cases. The low installation and operational costs, the reliability and simplicity of the method, indicate it may be useful for defining the epileptogenic regions in a variety of circumstances, including surgery for tumors, vascular malformations, and other cortical lesions associated with seizure disorders.
Assuntos
Eletroencefalografia/métodos , Epilepsia/cirurgia , Adulto , Análise Custo-Benefício , Eletroencefalografia/economia , Feminino , Humanos , Lactente , MasculinoRESUMO
Most investigators consider the caroticotympanic artery to be a normal branch of the petrous portion of the internal carotid artery, although some authors disagree. The present study was conducted on forty human temporal bones removed from adult cadavers of both sexes. Twenty pieces were injected and dissected under a surgical microscope, 10 pieces were injected and submitted to corrosion, and 10 were injected and diaphanized in order to observe the frequency of the caroticotympanic artery in the petrous portion of the internal carotid artery. The caroticotympanic artery was not observed in any of the pieces submitted to microdissection and was observed in only 1 of the pieces (10%) submitted to corrosion and also in 1 of the diaphanized pieces (10%). In both cases, only one artery was present. Based on the present results showing that the rate of occurrence of the caroticotympanic artery was very low by the three techniques utilized (microdissection 0%; corrosion 10%; diaphanization 10%), it is possible to conclude that, anatomically, the artery should be considered as a variation and not as a normal branch of the petrous portion of the internal carotid artery, in agreement with most literature reports.
Assuntos
Artéria Carótida Interna/anatomia & histologia , Orelha Média/anatomia & histologia , Orelha Média/irrigação sanguínea , Osso Petroso/anatomia & histologia , Osso Petroso/irrigação sanguínea , Artéria Carótida Interna/anormalidades , Feminino , Humanos , MasculinoRESUMO
Tuberous sclerosis complex is a group of autosomal disorders characterized by hamartomas and benign neoplastic lesions that invariably affect the central nervous system. We report a case of tuberous sclerosis that is the first presenting ultrastructural findings of this phacomatosis in the Latin American literature. The patient was a 2 year old girl presenting West syndrome non responsive to the clinical treatment with vigabatrin, trileptal and clonazepan, and undergoing left frontal lobectomy. The histopathological and ultrastructural findings were compatible with tuberous sclerosis. These results may help to further understand this controversial phacomatosis, warning to the clinical presentation as West syndrome.
Assuntos
Encéfalo/ultraestrutura , Esclerose Tuberosa/patologia , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Espasmos Infantis/diagnósticoRESUMO
Post-traumatic occlusion of middle cerebral artery is uncommon. Only forty nine cases have been adequately described in the literature. We present one such cases. The symptoms may simulate those of intranial hematoma and the angiography confirms the diagnosis. The mortality rates are high. The pathogenesis is not clearly understood and several explanations have been reported.