Um Caso Clínico de Ependimoma do Filum Terminal

Os ependimomas são tumores sólidos com origem nas células que delimitam o sistema ventricular e o canal ependimário. A sua localização habitual varia com a idade e, nos ependimomas espinhais, a sintomatologia é inespecífica o que motiva diagnósticos tardios. Os autores descrevem o caso clínico de uma criança de 9 anos de idade, com dor lombosagrada, alteração da marcha, postura anti-álgica e inversão da lordose lombar. A ressonância magnética nuclear (RMN) revelou um -tumor da cauda equina (filum terminal). Procedeu-se à excisão completa do tumor; o exame histológico permitiu diagnosticar um ependimoma mixo-papilar do filum terminal. No pós-operatório verificou-se retenção urinária transitória que resolveu gradualmente. Dois anos após a cirurgia o doente encontra-se assintomático persistindo apenas ausência dos reflexos aquilianos. Faz-se uma pequena abordagem das manifestações clínicas, diagnóstico e terapêutica dos ependimomas espinhais

Nanohybrid Materials with Tunable Birefringence via Cation Exchange in Polymer Films

In this work, a nanohybrid material based on a freestanding polymeric liquid crystal network capable of postmodification via cation exchange to tune birefringence is proposed. The smectic liquid crystal films can be infiltrated with a variety of cations, thereby changing the refractive indices (ne and no) and the effective birefringence (Δn) of the nanohybrid material, with reversible cation infiltration occurring within minutes. Birefringence could be tuned between values of 0.06 and 0.19, depending on the cation infiltrated into the network. Upon infiltration, a decrease in the smectic layer spacing is found with layer contraction independent of the induced change in birefringence. Potential applications are in the field of specialty optical devices, such as flexible, retunable reflective filters

O direito fundamental à educação em face das ações afirmativas

O presente trabalho tem por objetivo analisar a adoção das ações afirmativas no sistema de ensino brasileiro como mecanismo de concretização do direito fundamental social à educação. Aborda o desenvolvimento da educação como direito humano, tanto em âmbito nacional quanto internacional, e a consequente positivação deste direito no cenário nacional, conferindo caráter fundamental ao direito à educação. Para tanto, ao elencar o direito à educação como direito fundamental, exige-se do legislador infraconstitucional e do administrador pátrio a adoção de políticas públicas claramente delineadas e eficazes, para a presente consubstanciação. Palavras-chave: Direito fundamental social à educação. Ações afirmativas

Phylogenetic relationships of cone snails endemic to Cabo Verde based on mitochondrial genomes

Background: Due to their great species and ecological diversity as well as their capacity to produce hundreds of different toxins, cone snails are of interest to evolutionary biologists, pharmacologists and amateur naturalists alike. Taxonomic identification of cone snails still relies mostly on the shape, color, and banding patterns of the shell. However, these phenotypic traits are prone to homoplasy. Therefore, the consistent use of genetic data for species delimitation and phylogenetic inference in this apparently hyperdiverse group is largely wanting. Here, we reconstruct the phylogeny of the cones endemic to Cabo Verde archipelago, a well-known radiation of the group, using mitochondrial (mt) genomes. Results: The reconstructed phylogeny grouped the analyzed species into two main clades, one including Kalloconus from West Africa sister to Trovaoconus from Cabo Verde and the other with a paraphyletic Lautoconus due to the sister group relationship of Africonus from Cabo Verde and Lautoconus ventricosus from Mediterranean Sea and neighboring Atlantic Ocean to the exclusion of Lautoconus endemic to Senegal (plus Lautoconus guanche from Mauritania, Morocco, and Canary Islands). Within Trovaoconus, up to three main lineages could be distinguished. The clade of Africonus included four main lineages (named I to IV), each further subdivided into two monophyletic groups. The reconstructed phylogeny allowed inferring the evolution of the radula in the studied lineages as well as biogeographic patterns. The number of cone species endemic to Cabo Verde was revised under the light of sequence divergence data and the inferred phylogenetic relationships. Conclusions: The sequence divergence between continental members of the genus Kalloconus and island endemics ascribed to the genus Trovaoconus is low, prompting for synonymization of the latter. The genus Lautoconus is paraphyletic. Lautoconus ventricosus is the closest living sister group of genus Africonus. Diversification of Africonus was in allopatry due to the direct development nature of their larvae and mainly triggered by eustatic sea level changes during the Miocene-Pliocene. Our study confirms the diversity of cone endemic to Cabo Verde but significantly reduces the number of valid species. Applying a sequence divergence threshold, the number of valid species within the sampled Africonus is reduced to half.Spanish Ministry of Science and Innovation [CGL2013-45211-C2-2-P, CGL2016-75255-C2-1-P, BES-2011-051469, BES-2014-069575, Doctorado Nacional-567]info:eu-repo/semantics/publishedVersio

Enhancement of PLA-PVA surface adhesion in bilayer assemblies by PLA aminolisation

Data Availability: The raw/processed data required to reproduce these findings cannot be shared at this time due to legal or ethical reasons.Poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) present complementary barrier properties, and their combination in multilayer assemblies (laminates) could provide materials with more effective barrier capacity for food packaging purposes. However, their low chemical affinity compromises adequate polymer adhesion. Surface free energy modification of thermo-processed PLA films through treatment with 1,6-hexanediamine was used to enhance adhesion with polar PVA aqueous solutions. Treatments of 1 and 3 min increased the polar component of the solid surface tension, while treatments above 10 min provoked a corrosive effect in the films structure. Extensibility analyses of PVA solutions loaded with carvacrol (15 wt.%) and different Tween 85 ratios on PLA-activated surfaces allowed the selection of the 1-min aminolysed surface for obtaining PLA-PVA bilayers, by casting PVA solutions on the PLA films. This study revealed that despite aminolisation enhancing the PLA surface affinity for aqueous PVA solutions, casting-obtained bilayers presented limited oxygen barrier effectiveness due to heterogeneous thickness of PVA layer in the laminates.The authors acknowledge the financial support provided by the Ministerio de Economia y Competitividad (MINECO) of Spain (project AGL2016-76699-R). The author A. Tampau thanks MINECO for the pre-doctoral research grant #BES-2014-068100.info:eu-repo/semantics/publishedVersio

Effect of an edible nanomultilayer coating by electrostatic self-assembly on the shelf life of fresh-cut mangoes

This work aims at evaluating the effect of an alginate-chitosan nanomultilayer coating, obtained by electrostatic layer-by-layer self-assembling, in the quality and shelf life of fresh-cut mangoes. Coated and uncoated fresh-cut mangoes were stored under refrigeration (8 °C) for 14 days. The changes in mass loss, titratable acidity, pH, ascorbic acid content, total soluble solids, malondialdehyde content, browning rate, and microbial count were evaluated during storage. At the end of the storage period, lower values of mass loss, pH, malondialdehyde content, browning rate, soluble solids, microorganisms proliferation, and higher titratable acidity were observed in the coated mangoes. The nanomultilayer coating did not improve the retention of vitamin C during storage of fresh-cut mangoes. Results suggest that chitosan-alginate nanomultilayer edible coating extends the shelf life of fresh-cut mangoes up to 8 days.Author Marthyna Pessoa de Souza thanks Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil) and Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) for granting her scholarships. The authors thank the Fundacao para a Ciencia e a Tecnologia (FCT) Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, and FEDER (Portugal)