Computational algorithms for the segmentation of the human ear

The main goal of this project is to identify an efficient segmentation algorithm for each anatomic structure of the ear. Therefore, in this paper, it is presented and analyzed computational algorithms that have been used to segment structures in images, especially of the human ear in Computed Tomography (CT) images

Segmentation algorithms for ear image data towards biomechanical studies

In recent years, the segmentation, i.e. the identification, of ear structures in video-otoscopy, computerised tomography (CT) and magnetic resonance (MR) image data, has gained significant importance in the medical imaging area, particularly those in CT and MR imaging. Segmentation is the fundamental step of any automated technique for supporting the medical diagnosis and, in particular, in biomechanics studies, for building realistic geometric models of ear structures. In this paper, a review of the algorithms used in ear segmentation is presented. The review includes an introduction to the usually biomechanical modelling approaches and also to the common imaging modalities. Afterwards, several segmentation algorithms for ear image data are described, and their specificities and difficulties as well as their advantages and disadvantages are identified and analysed using experimental examples. Finally, the conclusions are presented as well as a discussion about possible trends for future research concerning the ear segmentation.info:eu-repo/semantics/publishedVersio

A method to automatically segment the internal ear structures in CT images

Hereby it is presents a novel methodology to segment the internal structures of the human ear based on image registration. The first step of the methodology concerns the registration of the volumetric image to be segmented with a reference volumetric image previously defined and manually segmented. Then, the geometric transformation found in the registration step is applied to the image to be segmented and consequently, the segmentation of this image is achieved. The methodology was applied on a set of images obtained by X-ray computed tomography revealing very promising results

In Vitro Hepatotoxic and Neurotoxic Effects of Titanium and Cerium Dioxide Nanoparticles, Arsenic and Mercury Co-Exposure

This article belongs to the Special Issue Toxicity of Nanomaterials and Legacy Contaminants: Risks to the Environment and Human Health.Considering the increasing emergence of new contaminants, such as nanomaterials, mixing with legacy contaminants, including metal(loid)s, it becomes imperative to understand the toxic profile resulting from these interactions. This work aimed at assessing and comparing the individual and combined hepatotoxic and neurotoxic potential of titanium dioxide nanoparticles (TiO2NPs 0.75-75 mg/L), cerium oxide nanoparticles (CeO2NPs 0.075-10 μg/L), arsenic (As 0.01-2.5 mg/L), and mercury (Hg 0.5-100 mg/L) on human hepatoma (HepG2) and neuroblastoma (SH-SY5Y) cells. Viability was assessed through WST-1 (24 h) and clonogenic (7 days) assays and it was affected in a dose-, time- and cell-dependent manner. Higher concentrations caused greater toxicity, while prolonged exposure caused inhibition of cell proliferation, even at low concentrations, for both cell lines. Cell cycle progression, explored by flow cytometry 24 h post-exposure, revealed that TiO2NPs, As and Hg but not CeO2NPs, changed the profiles of SH-SY5Y and HepG2 cells in a dose-dependent manner, and that the cell cycle was, overall, more affected by exposure to mixtures. Exposure to binary mixtures revealed either potentiation or antagonistic effects depending on the composition, cell type and time of exposure. These findings prove that joint toxicity of contaminants cannot be disregarded and must be further explored.This research was funded by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia in the framework of the project POCI-01-0145-FEDER-029651. This work was also financed by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of projects UIDB/04750/2020 and LA/P/0064/2020. This work was also developed within the scope of the project CICECO- Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). A.T. Reis thanks the financial support of FCT through individual Grant SFRH/BPD/122112/2016. C.B. Lopes and A.C. Estrada acknowledge their research position funded by national funds (OE), through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.info:eu-repo/semantics/publishedVersio

ISOLAMENTO, IDENTIFICAÇÃO E CARACTERIZAÇÃO DE MICROALGAS DE ÁGUA DOCE COMO FONTE POTENCIAL PARA A EXTRAÇÃO DE ÓLEO

A limitação das reservas de petróleo e seu uso e de seus derivados tem causado grandes preocupações no cenário econômico, social e ambiental. Fontes de energia renováveis, como biocombustíveis, tem sido vistas como uma ótima alternativa sustentável. O biodiesel é um biocombustível que tem ganhado grande atenção, sendo produzido no brasil a partir de diferentes espécies oleaginosas como mamona, canola, girassol, o amendoim e principalmente a soja. Entretanto, há várias limitações concernentes ao plantio e utilização dessas plantas. Uma promissora opção à essas oleaginosas são as microalgas, pois apresentam baixos custos de colheita e transporte, menor gasto de água e área de implantação menor comparado aos cultivos de plantas, além de poder ser realizado em condições não adequadas para a produção de outras culturas. Além do biodiesel, o óleo extraído das microalgas tem outros potenciais, entre eles a indústria farmacêutica, cosméticos, suplementos alimentares, entre outros. No presente projeto, amostras de microalgas de água doce do lago do centro de Matão-SP foram crescidas em meios de cultura com condições que estimularam o seu crescimento, isoladas e identificadas, e seu óleo foi caracterizado como fonte em potencial para futura produção de biodiesel. PALAVRAS-CHAVE: biodiesel; microalgas; óleo; energia renováveis; sustentabilidad

Herpetofauna of an urban environmental protection area in an Amazon forest remnant of Amapá state, northern Brazil

The herpetofauna of Amazonia biome is one of the richest in the world. However, there is a lack of information on its richness and distribution. Here we provide a list of the herpetofauna from the Environmental Protection Area of Lagoa dos Índios, state of Amapá, Brazil, in the northern Amazon Forest. Sampling effort was conducted by active search in three distinct transects from January to May 2018 (rainy season) and August to December 2019 (drought season). We recorded 46 species composing the local herpetofauna, being 18 amphibians and 28 reptiles. Scinax ruber, Gonatodes humeralis and Helicops angulatus were the most abundant species. Regarding the conservation status, two species are categorized as Date Data deficient, (Lysapsus bolivianus and Eunectes deschauenseei), and one as Vulnerable (Podocnemis unifilis) in the Red List of the International Union for Conservation of Nature. Podocnemis unifilis is also considered Near Threatened in the Brazilian Red List of Endangered Species. Our results suggest that local biodiversity is still underestimated and, if expanded, could increase the species richness in the area. This study represents preliminary trends and raise further questions concerning the herpetofauna assemblage of Eastern Brazilian Amazonia.El bioma de la herpetofauna de la Amazonia es uno de los más ricos del mundo. Sin embargo, falta información sobre su riqueza y distribución. Aquí proporcionamos una lista de la herpetofauna del Área de Protección Ambiental de Lagoa dos Índios, estado de Amapá, Brasil, en el norte de la Selva Amazónica. El esfuerzo de muestreo se realizó mediante búsqueda activa en tres transectos distintos de enero a mayo de 2018 (temporada de lluvias) y de agosto a diciembre de 2019 (temporada de sequía). Registramos 46 especies que componen la herpetofauna local, siendo 18 anfibios y 28 reptiles. Scinax ruber, Gonatodes humeralis y Helicops angulatus fueron las especies más abundantes. En cuanto al estado de conservación, dos especies están categorizadas como Datos deficientes en fecha, (Lysapsus bolivianus y Eunectes deschauenseei), y una como Vulnerable (Podocnemis unifilis) en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza. Podocnemis unifilis también se considera Casi Amenazada en la Lista Roja Brasileña de Especies Amenazadas. Nuestros resultados sugieren que la biodiversidad local todavía se subestima y, si se amplía, podría aumentar la riqueza de especies en el área. Este estudio representa tendencias preliminares y plantea más preguntas sobre el conjunto de herpetofauna de la Amazonia brasileña oriental.Asociación Herpetológica Argentin

Activity of scorpion venom-derived antifungal peptides against planktonic cells of Candida spp. and Cryptococcus neoformans and Candida albicans Biofilms

The incidence of fungal infections has been increasing in the last decades, while the number of available antifungal classes remains the same. The natural and acquired resistance of some fungal species to available therapies, associated with the high toxicity of these drugs on the present scenario and makes an imperative of the search for new, more efficient and less toxic therapeutic choices. Antimicrobial peptides (AMPs) are a potential class of antimicrobial drugs consisting of evolutionarily conserved multifunctional molecules with both microbicidal and immunomodulatory properties being part of the innate immune response of diverse organisms. In this study, we evaluated 11 scorpion-venom derived non-disulfide-bridged peptides against Cryptococcus neoformans and Candida spp., which are important human pathogens. Seven of them, including two novel molecules, showed activity against both genera with minimum inhibitory concentration values ranging from 3.12 to 200 μM and an analogous activity against Candida albicans biofilms. Most of the peptides presented low hemolytic and cytotoxic activity against mammalian cells. Modifications in the primary peptide sequence, as revealed by in silico and circular dichroism analyses of the most promising peptides, underscored the importance of cationicity for their antimicrobial activity as well as the amphipathicity of these molecules and their tendency to form alpha helices. This is the first report of scorpion-derived AMPs against C. neoformans and our results underline the potential of scorpion venom as a source of antimicrobials. Further characterization of their mechanism of action, followed by molecular optimization to decrease their cytotoxicity and increase antimicrobial activity, is needed to fully clarify their real potential as antifungals