Uncommon presentations of angiofibroma in sinonasal tract: a two-case report/ Apresentações incomuns de angiofibromas no trato nasossinusal: relato de dois casos

Juvenile nasopharyngeal angiofibroma (JNA) are rare, histologically benign, but locally aggressive, vascular tumors of the nasopharynx that affects predominantly male adolescents, its origins from other sites is denominated extranasopharyngeal angiofibroma (ENPA), which is an even rarer entity afflicting more females and young adults, representing a diagnostic and therapeutic challenge to rhinologists. In this report we present 2 cases of similar clinical presentation, with unilateral nasal obstruction and previous episodes of nasal bleeding. One patient is a 14-year-old male with a soft-tissue mass occupying nasopharynx, middle meatus, and right nasal cavity. The second patient is a 12-year-old male with a soft-tissue lesion rising from right sphenoid sinus and obliterating right nasal cavity, obstructing ipsilateral maxillary sinus, ethmoidal cells, and frontal sinus. Both patients underwent complete endoscopic excision of the lesions, the first one recurred on sphenoid sinus and the second showed no recurrence after 2 years of post-operative follow-up. The unusual sites and presentations make these rare cases and thus worth of reporting

Edge-Reconstructed, Few-Layered Graphene Nanoribbons: Stability and Electronic Properties

We report a first-principles study of edge-reconstructed, few-layered graphene nanoribbons. We find that the nanoribbon stability increases linearly with increasing width and decreases linearly with increasing number of layers (from three to six layers). Specifically, we find that a three-layer 1.3 nm wide ribbon is energetically more stable than the C₆₀ fullerene, and that a 1.8 nm wide ribbon is more stable than a (10,0) carbon nanotube. The morphologies of the reconstructed edges are characterized by the presence of five-, six-, and sevenfold rings, with sp³ and sp² bonds at the reconstructed edges. The electronic structure of the few-layered nanoribbons with reconstructed edges can be metallic or semiconducting, with band gaps oscillating between 0 and 0.28 eV as a function of ribbon width

Graphene/h-BN in-plane heterostructures : stability and electronic and transport properties.

We present a first-principles study of structural, electronic, and transport properties of in-plane Gr:BN heterostructures in the form of graphene stripes embedded in a BN matrix. In our calculations, we consider carbon, nitrogen, and boron chemical potentials that are consistent with growth conditions (gas sources and temperatures) at either nitrogen-rich or boron-rich environments. Interestingly, we find that structures with excess of B atoms can be energetically more stable than structures with excess of N atoms even in N-rich growth conditions. The general trend is that N-rich growth conditions favor B/N stoichiometric heterostructures, while B-rich growth conditions favor heterostructures with excess of B atoms at the graphene/BN junctions, such that only B?C bonds occur at both edges of a graphene stripe region embedded in BN. We also investigate the dependence of magnetic properties and the band gap magnitudes of graphene stripe regions embedded in BN with several structural characteristics. We find that graphene stripes with only one bond type (either B?C or N?C) at the graphene/BN edges always present metallic behavior, with zigzag-oriented stripes of this type presenting large magnetic moments. Finally, we obtain the characteristic I?V curves for systems formed by junctions of two graphene stripes embedded in BN, one of them terminated by C?N bonds and the other terminated by C?B bonds. We find that systems of this type should present rectifying behavior

Resumo: A fração diclometano de Moquiniastrum polymorphum potencializa a atividade citotóxica de diferentes agentes antitumorais em linhagem de câncer de mama MCF-7. PECIBES, supl.1, 19, 2015

Moquiniastrum polymorphum, popularmente conhecido como Cambará, apresenta diversos componentes com propriedades biológicas, tais como lactonas sesquiterpênicas (LS), driterpenos, triterpenos, flavonóides e cumarinas. Este trabalho avaliou a atividade citotóxica da fração diclorometano (DCM) de M. polymorphum em adenocarcinoma de mama humano (MCF-7), combinado ou não com diferentes agentes antitumorais. Foi utilizado o ensaio de viabilidade celular MTT e a partir destes dados utilizou-se o software CompuSyn para estimar os índices de combinação entre os antitumorais e o DCM. O DCM mostrou-se citotóxico nesta linhagem celular. Nos estudos de combinação de drogas, as associações do DCM com o irinotecano, paclitaxel, 5-fluorouracil e cisplatina apresentaram comportamento antagonista, o que sugere que o DCM pode apresentar mecanismo de ação semelhante a estes agentes. Entretanto, as combinações do DCM com a doxorrubicina e o tamoxifeno apresentaram aditivismo. O tamoxifeno atua em receptores de estrógeno induzindo morte celular, enquanto que a doxorrubicina é inibidor de topoisomerase II e também intercalante de DNA. A caracterização da fração DCM demonstrou grande quantidade de LS. Estudos de combinação de agentes antitumorais permitem o conhecimento dos perfis dos mesmos, bem como suas interações e seus mecanismos de ação

The IFN-³+874T/A gene polymorphism is associated with retinochoroiditis toxoplasmosis susceptibility

Toxoplasmosis is a worldwide zoonosis that generally produces an asymptomatic infection. In some cases, however, toxoplasmosis infection can lead to ocular damage. The immune system has a crucial role in both the course of the infection and in the evolution of toxoplasmosis disease. In particular, IFN-³ plays an important role in resistance to toxoplasmosis. Polymorphisms in genes encoding cytokines have been shown to have an association with susceptibility to parasitic diseases. The aim of this work was to analyse the occurrence of polymorphisms in the gene encoding IFN-³ (+874T/A) among Toxoplasma gondii seropositive individuals, including those with ocular lesions caused by the parasite, from a rural population of Santa Rita de Cássia, Barra Mansa, state of Rio de Janeiro, Brazil. Further, we verified which of these polymorphisms could be related to susceptibility to the development of ocular toxoplasmosis. This study included 34 individuals with ocular toxoplasmosis (ocular group) and 134 without ocular lesions (control group). The differences between A and T allele distributions were not statistically significant between the two groups. However, we observed that a higher frequency of individuals from the ocular group possessed the A/A genotype, when compared with the control group, suggesting that homozygocity for the A allele could enhance susceptibility to ocular toxoplasmosis in T. gondii infection