Micro/nano-structured superhydrophobic surfaces in the biomedical field: part I: basic concepts and biomimetic approaches

Part II is available at: http://hdl.handle.net/1822/44292Inspired by natural structures, great attention has been devoted to the study and development of surfaces with extreme wettable properties. The meticulous study of natural systems revealed that the micro/nano-topography of the surface is critical to obtaining unique wettability features, including superhydrophobicity. However, the surface chemistry also has an important role in such surface characteristics. As the interaction of biomaterials with the biological milieu occurs at the surface of the materials, it is expected that synthetic substrates with extreme and controllable wettability ranging from superhydrophilic to superhydrophobic regimes could bring about the possibility of new investigations of cellâ material interactions on nonconventional surfaces and the development of alternative devices with biomedical utility. This first part of the review will describe in detail how proteins and cells interact with micro/nano-structured surfaces exhibiting extreme wettabilities.AC Lima is grateful for financial support from Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BD/71395/2010 (under the scope of QRENPOPH – Tipologia 4.1 – Formação Avançada subsidized by European Social Found as well as by national funds of MEC). The authors also acknowledge the national funds from the FCT in the scope of project PTDC/CTM-BIO/1814/2012. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript

Mecanoterapia e fortalecimento muscular: um embasamento seguro para um tratamento eficaz

Trata-se de um estudo sobre a eficácia dos dispositivos mecânicos fisioterapêuticos no ganho de força, mediante uma fundamentação fisiológica e biomecânica associado a correlações clínicas. A metodologia utilizada reporta-se a uma revisão bibliográfica através da verificação e comparação de textos de livros e artigos de revistas científicas. Apesar do sucesso de um plano de fortalecimento muscular ter uma relação intrínseca com um embasamento teórico conciso, a bibliografia disponível que correlaciona mecanoterapia e fortalecimento muscular é escassa e as informações, muitas vezes, são fragmentadas. Assim este trabalho possibilitou a listagem dos dispositivos mecânicos, fornecendo dados que podem ser úteis para a realização de futuros estudos clínicos

Label-free multi-step microfluidic device for mechanical characterization of blood cells: Diabetes type II

The increasing interest to establish significant correlations between blood cell mechanical measurements and blood diseases, has led to the promotion of microfluidic devices as attractive clinical tools for potential use in diagnosis. A multi-step microfluidic device able to separate red and white blood cells (RBCs and WBCs) from plasma and simultaneously measure blood cells deformability (5 and 20% of hematocrit) is presented in this paper. The device employs passive separation based on the cross-flow filtration principle, introduced at each daughter channel. At the outlets, hyperbolic geometries allow single-cell deformability analysis. The device was tested with blood from five healthy and fifteen diabetic type II voluntary donors. The results have shown that WBCs have lower deformability than RBCs, and no significant differences were observed in WBCs from healthy and pathological blood samples. In contrast, RBCs have shown significant differences, with pathological cells exhibiting lower deformability. Shear rheology has shown that blood from patients with type II diabetes has higher viscosity than blood from healthy donors. This microfluidic device has demonstrated the ability to reduce cell concentration at the outlets down to 1%, an ideal cell concentration for assessing the blood cells deformability, under healthy and pathological conditions. The results provide new insights and quantitative information about the hemodynamics of in vitro type II diabetes mellitus RBCs. Thus, such device can be a promising complement in clinical diagnosis and biological research as part of an integrated blood-on-a-chip system.This work was supported by Projects NORTE-01-0145-FEDER- 028178, NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER- 030171 funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER. This work was also supported by Fundação para a Ciência e a Tecnologia (FCT) under the strategic grants UIDB/04077/2020 and UIDB/00532/2020. D. Pinho and V. Faustino acknowledge the Ph.D. scholarships SFRH/BD/89077/2012 and SFRH/BD/99696/2014, respectively, both provided by FCT. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIND. F. T. Pinho is thankful to FCT for financial support through projects LA/P/0045/2020 of the Associate Laboratory in Chemical Engineering (ALiCE) and projects UIDB/00532/2020 and UIDP/00532/2020 of Centro de Estudos de Fenómenos de Transporte.info:eu-repo/semantics/publishedVersio

Evolution at a Different Pace: Distinctive Phylogenetic Patterns of Cone Snails from Two Ancient Oceanic Archipelagos

Ancient oceanic archipelagos of similar geological age are expected to accrue comparable numbers of endemic lineages with identical life history strategies, especially if the islands exhibit analogous habitats. We tested this hypothesis using marine snails of the genus Conus from the Atlantic archipelagos of Cape Verde and Canary Islands. Together with Azores and Madeira, these archipelagos comprise the Macaronesia biogeographic region and differ remarkably in the diversity of this group. More than 50 endemic Conus species have been described from Cape Verde, whereas prior to this study, only two nonendemic species, including a putative species complex, were thought to occur in the Canary Islands.We combined molecular phylogenetic data and geometric morphometrics with bathymetric and paleoclimatic reconstructions to understand the contrasting diversification patterns found in these regions. Our results suggest that species diversity is even lower than previously thought in the Canary Islands, with the putative species complex corresponding to a single species, Conus guanche. One explanation for the enormous disparity in Conus diversity is that the amount of available habitat may differ, or may have differed in the past due to eustatic (global) sea level changes. Historical bathymetric data, however, indicated that sea level fluctuations since the Miocene have had a similar impact on the available habitat area in both Cape Verde and Canary archipelagos and therefore do not explain this disparity.We suggest that recurrent gene flow between the Canary Islands andWest Africa, habitat losses due to intense volcanic activity in combination with unsuccessful colonization of new Conus species from more diverse regions, were all determinant in shaping diversity patterns within the Canarian archipelago.Worldwide Conus species diversity follows the well-established pattern of latitudinal increase of species richness from the poles towards the tropics. However, the eastern Atlantic revealed a striking pattern with two main peaks of Conus species richness in the subtropical area and decreasing diversities toward the tropical western African coast. A Random Forestsmodel using 12 oceanographic variables suggested that sea surface temperature is the main determinant of Conus diversity either at continental scales (eastern Atlantic coast) or in a broader context (worldwide). Other factors such as availability of suitable habitat and reduced salinity due to the influx of large rivers in the tropical area also play an important role in shaping Conus diversity patterns in the western coast of Africa. [Conus; eustatic sea level changes; latitudinal gradient of species diversity; oceanic islands; RF models; species diversity; SST.

Novel benzo[α]phenoxazinium chlorides functionalized with sulfonamide groups as NIR fluorescent probes for vacuole, endoplasmic reticulum, and plasma membrane staining

The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.FCT (Fundação para a Ciência e Tecnologia, Portugal) and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centers CQ/UM (UID/QUI/00686/2021), and CBMA (Ref. UIDB/04050/2020), as well as a PhD grant to J. C. Ferreira (SFRH/BD/133207/2017 and COVID/BD/151978/2021). The NMR spectrometer Bruker Avance III 400 (part of the National NMR Network) was financed by FCT and FEDER

Biopsia do cório fetal em cães

With the great development of the gestational studies in all of the species, we noticed the necessity of adaptations of these techniques for prenatal diagnosis in dogs. Based on this, we studied the feasibility of chorion biopsy guided by ultrasound. Our results demonstrated accuracy on the sex determination being 2 males and 12 females, as well as it would be possible to identify chromosome alteration due to the quality of samplings. Sex determination was accomplished with the identification of Y gene chromosomes in PCR technique. After the collection, fragments were prepared for light microscopy studies and revealed fetal chorion tissue, blood colloid and erythrocyte. In the whole material we found hemosiderin impregnations due to the hemolysis and to the residue of blood of the placental marginal hematomes. The submitted female dogs to this technique demonstrated normal puppy births without death.Com o grande desenvolvimento dos estudos gestacionais em todas as espécies, percebemos a necessidade de adaptarmos técnicas para diagnóstico pré-natal para cães. Assim, buscamos bases nas técnicas já existentes empregadas em humanos, e através destas, conseguimos estabelecer um método para coleta em cães, utilizando PCR para garantirmos a integridade das amostras. O procedimento foi realizado através de punção da cinta placentária com agulha de biopsia guiada por ultra-som. De todas as 14 amostras coletadas, duas apresentaram-se positivas para o cromossomo Y, presente apenas em machos, confirmando assim a viabilidade das amostras demonstrando com isso que através desta técnica podemos coletar material fetal para diagnóstico de alterações gênicas ou cromossômicas presentes nos cães antes mesmo destes virem a termo. A microscopia de material revelou fragmentos de cório fetal, colóide sangüíneo e eritrócitos. Em todo o material encontramos impregnações de hemosiderina devido à hemólise e ao resíduo de sangue dos hematomas marginais placentários. As cadelas submetidas a esta técnica tiveram partos normais sem óbito de nenhum filhote.FAPES

Aspectos Morfológicos do cordão umbilical de búfalos (Bubalus bubalis)

Buffalo is an important livestock resource, with a great participation in agricultural systems, providing milk, meat, and work power. Umbilical cord is responsible for maternal-fetal nutrients exchange during pregnancy, and its alterations can compromise the fetal development. We investigated ten pregnant uteruses collected from cross-bread buffaloes in different stages of gestation. Pregnancy and fetal age was determined by measuring the apex sacral length and development period was calculated by previously published formula. Umbilical cords were measured for length determination. Umbilical cord vascular net and anastomosis were observed by injection of Neoprene latex. Histological sections of the umbilical cord were studied after stain with HE, picrossirius, toluidine blue, orceine, and PAS reaction. Buffaloes' umbilical cord was formed by two central arteries, an allantois duct and two peripheral veins. The artery wall was composed by large quantity of collagen, elastic fibers, fibroblasts and large number of vasa vasorum. The allantois duct was located between the arteries and presented a great number of small nourishing vessels. Small nourishing vessels should be carefully considered to avoid to be mistaken to the arterials and veins vasa vasorum. Medium length of umbilical cord from buffalos was 11.8cm (minimum of 6.8cm and maximum of 17.4cm).Búfalo é uma importante fonte de recurso nos rebanhos animais, apresentando uma grande participação na agropecuária, provendo leite, carne e força de trabalho. O Cordão umbilical é responsável pela troca de nutrientes materno-fetais durante a gestação, e suas alterações podem comprometer o desenvolvimento fetal. Nós investigamos dez úteros gravídicos de búfalos de raças cruzadas em fases diferentes de gestação. O período de gestação e a idade fetal foram determinados pelo comprimento ápice sacral, aplicando fórmulas previamente estabelecidas. Posteriormente mediu-se o comprimento do cordão umbilical. A rede vascular do cordão umbilical e anastomoses foram observadas por injeção ou látex de neoprene. O cordão umbilical foi estudado a partir de cortes histológicos, corados por HE, picrossirius, azul de Toluidina, orceína e reação histoquímica de PAS. O cordão umbilical de búfalos é formado por duas artérias centrais, ducto alantóide e duas veias periféricas e apresentam forma de ampulheta. A parede da artéria umbilical é composta por grande quantidade de fibras colágenas e elásticas, fibroblastos e um grande número de vasa vasorum. O ducto alantóide fica alocado entre as artérias e apresenta um grande número de pequenos vasos nutritivos. Os vasos nutritivos devem ser cuidadosamente identificados para evitar-se confundi-los com vasa vasorum. O comprimento médio do cabo de cordão umbilical dos búfalos era 11.8cm (mínimo de 6.8cm e máximo de 17.4cm)

Exploring the impact of structural rigidification of amino-substituted bio-inspired flavylium dyes in DSSCs

Publisher Copyright: © 2023 The AuthorsSharing with anthocyanins the 2-phenyl-1-benzopyrylium structural motif, flavylium derivatives are strongly colored bio-inspired dyes that have been explored in dye-sensitized solar cells (DSSCs). Following on the fact that the most efficient flavylium-based dyes for DSSCs require amine electron-donating groups, a diethylamino group and the corresponding rigidified julolidine group were introduced in the benzopyrylium core. This structural variation was combined with another structural parameter – increased planarization of the flavylium ring system – to yield four flavylium derivatives all with a catechol anchoring group. The several pKa values of the new dyes and the UV–vis absorption data at different pH values and upon adsorption to TiO2 (corroborated by TD-DFT calculations) demonstrate a stronger delocalization of the nitrogen lone pair in the julolidine systems when compared to the diethylamino ones, reflecting the stronger electron-donating ability of the former. However, the julolidine-based dyes resulted in a decrease in all DSSC parameters, with efficiencies of 0.6% vs. 2.3% for the diethylamino devices. Discarding eventual increased self-aggregation processes of the more planar julolidine derivatives through studies with a de-aggregating agent (CDCA), and determining comparable dye loadings for all dyes, the presence of increased back-electron transfer processes for the julolidine-based compounds is advanced to explain their lower efficiencies. Rigidification of the flavylium dyes by bridging the benzopyrylium and the phenyl rings is demonstrated by higher fluorescence quantum yields and by electrochemical data and leads to a slight increase in the efficiency of the respective DSSCs. The results contribute to consolidate the potential of flavylium dyes as sensitizers for DSSCs.publishersversionpublishe

Public perceptions of hazards associated with Brazil nuts (Bertholletia excelsa) : evaluation of risk within an European context

One of the most important economic plants of the Amazon is the Brazil nut (Bertholletia excelsa). Brazil nuts for international trade are mainly obtained from wild collection rather than from plantations, often cited as one of the most important products of extractive reserves in Amazonia. The European Commission (2003/493/EC) has imposed strict regulations on the import from Brazil of Brazil nuts in their shells, as the shells have been found to contain high levels of aflatoxins, which can lead to liver cancer. This may have a negative impact on the Brazilian exports of shelled Brazil nuts, due to possible public awareness. The aim of the present research is to assess public perceptions regarding Brazil nuts and to contrast these with other nuts in general through the use of the Portuguese version of the Perceived Food Risk Index (PFRI). A sample of 418 consumers was drawn through a door-to-door interview using a random route walk procedure and following a quota sampling controlled for sex, age and location. Consumers were asked to choose the most relevant quality and preservation characteristics and to identify their consumption patterns for Brazil nuts and for nuts in general. Risk perception was evaluated over ten risk characteristics, for each of the following hazards: i) aflatoxins; ii) biological contaminants; iii) organoleptic changes; iv) fragments and strange bodies and v) microbial contamination. Additionally, subjects were asked to rate the probability of each hazard occurring in Brazil nuts or in nuts in general. Results show high consumptions of nuts in general, and a reduced consumption of Brazil nuts, although with low differences on the dimensions of risk perception. Concluding, this work adds to knowledge about the perceptions of risk connected to Brazil nuts consumption, namely that consumers perceive Brazil nuts as safe as nuts in general