One of the most interesting hemodynamic phenomenon observed both in vivo and in vitro studies is known as Fahraeus-Lindqvist effect, in which the apparent blood viscosity decreases as the tube diameter is reduced, for narrow tubes (< 300 μm). The physical reason behind this phenomenon is the creation of a marginal cell-free layer at regions adjacent to the tube wall. Although intensively studied, the complex formation of the cell-free layer has not yet been convincingly described mainly due to multi-physical and hemorheological factors that affect this phenomenon. The main purpose of this experimental work is to study the effect of the hematocrit (Hct) and temperature on the thickness of the cell-free layer in both glass capillaries and circular polydimethylsiloxane (PDMS) microchannels using an optical technique. The internal diameter of the glass and PDMS microchannels are 100 m and 73±2 m, respectively. The microchannels were placed on the stage of the inverted microscope and the temperature of the stage was adjusted by means of a thermo plate controller. The flow rate of the working fluids was controlled using a syringe pump. The images were recorded using a confocal microscopy system and transferred to the computer to be evaluated in Image J (NIH) using different plug-ins (MTrackJ and FeatureJ). The recorded images show a clear formation of a cell-free layer of variable thickness depending on experimental conditions.

São apresentados resultados experimentais de medições efectuadas na análise do salto em altura com agachamento, na amostra de um conjunto de indivíduos do sexo masculino e feminino. Foram realizados cinco ensaios para três níveis de agachamento inicial, com monitorização de um acelerómetro colocado na zona pélvica e com um sistema de análise de movimento assistido por vídeo e computador. Os resultados permitiram efectuar a comparação, entre o conjunto de indivíduos, dos parâmetros cinemáticos mais importantes, tendo em consideração os dois métodos experimentais. O estudo da fase impulsiva permitiu concluir que a massa de cada indivíduo tem influência na taxa de variação da força propulsiva e pouca influência no tempo utilizado para preparação da descolagem.

O corpo humano pode ser definido através de um sistema de segmentos articulados em equilíbrio dinâmico, sendo o movimento causado por forças internas e externas, provocando variações angulares dos segmentos. Este estudo pretende apresentar uma síntese da análise do comportamento do movimento plano, preparatório de salto do corpo humano, com contra movimento. Serão considerados diferentes modelos de análise, baseados em modelos de corpo rígido articulados, com massa concentrada, massa distribuída e com diferentes formas geométricas. São comparadas diferentes soluções numéricas com diferentes níveis de aproximação, avaliando diferentes regras de integração numérica.

O fenómeno das falsas memórias tem sido amplamente estudado, verificando-se de modo consistente que não existem testemunhos sem erros. Perceber que fatores influenciam a sua criação torna-se crucial, já que este conhecimento pode permitir a deteção de testemunhos pouco fiáveis. Com este estudo, pretendeu-se avaliar a relação que o stresse e a ansiedade têm na criação de falsas memórias. Para o efeito, apresentaram-se vídeos de crime e neutros a 80 participantes (40 participaram na condição crime e os restantes na condição neutra). Foi pedido a cada participante que respondesse a escalas de stresse e de ansiedade em três momentos distintos. Realizaram ainda uma tarefa de evocação livre e responderam a questões específicas sobre o vídeo visionado. Os resultados revelaram que o stresse e a ansiedade não influenciam a construção de falsas memórias, contrariamente ao esperado. As percentagens de falsas memórias por tipo de filme e por género são também exploradas.

Os sapais são ecossistemas marinhos altamente produtivos que frequentemente recebem contaminantes de natureza antropogénica. A Ria de Aveiro encontra-se no noroeste de Portugal e contém numerosos sapais. Halimione portulacoides é um dos halófitos mais importantes em sapais Europeus e tem sido amplamente estudada devido ao seu potencial para ser usada em fins de fitorremediação, e como bioindicador de contaminação de sedimentos. Bactérias endofíticas podem apresentar capacidade promotora do crescimento de plantas (PCP), quer diretamente por produção de fito-hormonas e aquisição de nutrientes, quer indiretamente via competição com fitopatogenos. No presente trabalho, a diversidade de bactérias endofíticas da planta de sapal H. portulacoides da Ria de Aveiro é explorada extensivamente. Isolados de bactérias endofíticas foram obtidos e caracterizados quanto à sua taxonomia, capacidade de produzir enzimas e características PCP. As características mais observadas foram atividade celulolítica, xilanolítica e desaminase de 1-aminociclopropano-1-carboxilato, e a produção da auxina ácido indol-3-acético. Os resultados revelaram um enorme potencial da coleção para PCP in vitro e in vivo. A coleção de isolados foi também explorada para procurar diversidade não descrita. Como resultado, dez novas espécies de bactérias foram amplamente caracterizadas e descritas: Microbacterium diaminobutyricum, Saccharospirillum correiae, Altererythrobacter halimionae, Altererythrobacter endophyticus, Zunongwangia endophytica, Salinicola halimionae, Salinicola aestuarina, Salinicola endophytica, Salinicola halophytica e Salinicola lusitana. Consequentemente, o presente trabalho expôs a endosfera de H. portulacoides como um foco de diversidade bacteriana desconhecida. A composição taxonómica da comunidade endofítica foi averiguada via sequenciação do gene 16S rRNA da coleção de isolados, e mais profundamente com a utilização de sequenciação de alto rendimento independente do cultivo. A última abordagem revelou cinco filos principais: Proteobacteria, Planctomycetes, Actinobacteria, Bacteroidetes e Firmicutes. Destes, apenas Planctomycetes não foi obtido na coleção de isolados. As comunidades diferiram de acordo com o local (no ensaio dependente do cultivo, para locais contaminados e não-contaminado) e tecido (em ambos os ensaios) de amostragem. As principais famílias obtidas no endofitoma nuclear foram Oceanospirillaceae em tecidos de parte aérea, e Enterobacteriaceae e Kiloniellaceae em tecidos de raiz. O trabalho apresentado providenciou uma compreensão profunda das bactérias endofíticas presentes no halófito H. portulacoides, e expôs o seu potencial como foco de bactérias não descritas e bactérias promotoras do crescimento de plantas.

Eyewitness memory is widely studied in the forensic context, due to their proneness to make unreliable testimonies. Understanding which factors may impact memory is determinant to avoid wrongful convictions in court. In this exploratory study, the relation between stress and anxiety and memory errors (spontaneous and induced) was analyzed being hypothesized that negative emotions may impair memory performance. Crime and neutral videos were presented to 80 volunteer university students in a between subject-design. They were asked to fill some stress and anxiety scales throughout the experimental task, as well as a free recall task. Also, it was presented several questions about the videos in which spontaneous and induced errors were assessed. Results suggests that stress and anxiety did not influence the quantity of memory errors for both genders. However, overall memory performance was poor for both conditions. Our results were discussed in light to existing theories about the relation between stress-anxiety and memory

Heavy metal resistant microorganisms are often associated with acidic environments, since metals are easily solubilized in acidic milieus. A unique yeast species from the Cryptococcus genus was isolated from two sulfur-rich acidic environments: acid mine drainage in the south of Portugal and a volcanic river in Argentina. The uniqueness of this species lies on the fact that it is the first acidophilic basidiomycetous yeast known to date. Additionally, the two strains chosen for this work (one from each environment) are resistant to high levels of heavy metals (arsenic, cadmium, copper and zinc). Metal resistance mechanisms are only described for neutrophilic yeasts, and mainly involve thiolated peptides and efflux transporters. To unveil the mechanisms that allow this Cryptococcus species to resist high levels of heavy metals, physiological, cytological and molecular approaches were conducted. Since both isolation sites are sulfur-rich, the possibility that this element influences metal resistance was assessed with microscale growth assays by determining minimal inhibitory concentrations of the four metals in differential sulfate availability conditions. Assessment of thiolmediated resistance mechanisms was achieved by incubating cells (grown with and without metal) with the thiol-specific fluorescent probe 5-chloromethylfluorescein-diacetate. Dot blot hybridization was applied to detect gene homologues involved in arsenic extrusion, and vacuolar metal-thiol accumulation in response to arsenic and cadmium. Also, suppression subtractive hybridization was conducted to investigate resistance to cadmium by analyzing transcripts induced upon exposure to this metal. Our results indicate that thiolated peptides are involved in resistance to arsenic and zinc in the Portuguese strain, cadmium in the Argentinean strain, and copper in both strains. Also, both strains presented evidence of an arsenic extrusion mechanism, and of a Cd-induced demand in protein synthesis and folding. Thus, the present work allowed unveiling of heavy metal resistance mechanisms in two strains of this unique novel yeast species, Cryptococcus sp.

Thermal spring waters (TSW) have been employed forntherapeutic purposes across the centuries being increasingly recognized for its unique benefits in skin health, in which immunomodulatory effects play a crucial role. By reviewing the literature, the multifaceted properties of TSW, which arise from its diverse mineral composition as well as its thermal characteristics, revealed the strong potential of these waters to aid in managing various chronic skin disorders, holding also a significant promise in cosmeceutical formulation.

Extracellular matrix (ECM)-based bioinks have been steadily gaining interest in the field of bioprinting to develop biologically relevant and functional tissue constructs. Herein, we propose the use of supercritical carbon dioxide (scCO2) technology to extract the ECM components of cell-sheets that have shown promising results in creating accurate 3D microenvironments replicating the cellâ s own ECM, to be used in the preparation of bioinks. The ECM extraction protocol best fitted for cell sheets was defined by considering efficient DNA removal with a minor effect on the ECM. Cell sheets of human dermal fibroblasts (hDFbs) and adipose stem cells (hASCs) were processed using a customised supercritical system by varying the pressure of the reactor, presence, exposure time, and type of co-solvent. A quantification of the amount of DNA, protein, and sulfated glycosaminoglycans (sGAGs) was carried out to determine the efficiency of the extraction in relation to standard decellularization methodologies. The bioinks containing the extracted ECM were fabricated by combining them with alginate as a support polymer. The influence of the alginate (1%, 2% w/vol) and ECM (0.5% and 1.5% w/vol) amounts on the printability of the blends was addressed by analysing the rheological behaviour of the suspensions. Finally, 3D printed constructs were fabricated using an in-house built extrusion-based bioprinter, and the impact of the extrusion process on cell viability was assessed. The optimised scCO2 protocol allowed efficient removal of DNA while preserving a higher number of proteins and sGAGs than the standard methodologies. The characterization of extractâ s composition also revealed that the ECM produced by hDFbs (fECM) and hASCs (aECM) is distinctively affected by the extraction protocols. Furthermore, rheological analysis indicated an increase in viscosity with increasing ECM composition, an effect even more prominent in samples containing aECM. 3D printing of alginate/ECM constructs demonstrated that cell viability was only marginally affected by the extrusion process, and this effect was also dependent on the ECM source. Overall, this work highlights the benefits of supercritical fluid-based methods for ECM extraction and strengthens the relevance of ECM-derived bioinks in the development of printed tissue-like constructs.

<jats:p>Agricultural soils are responsible for ecological functions and services that include primary production of food, fiber and fuel, nutrient cycling, carbon cycling and storage, water infiltration and purification, among others. Fungi are important drivers of most of those ecosystem services. Given the importance of fungi in agricultural soils, in this study, we aimed to characterize and analyse the changes of the soil fungal communities of three cropping systems from Madeira Island, where family farming is predominant, and investigate the response of fungi and its functional groups to soil physicochemical properties. To achieve that, we sequenced amplicons targeting the internal transcribed spacer 1 (ITS1) of the rRNA region, to analyse soil samples from 18 agrosystems: 6 vineyards (V), 6 banana plantations (B) and 6 vegetable plantations (H). Our results showed that alpha diversity indices of fungal communities are similar in the three cropping systems, but fungal composition and functional aspects varied among them, with more pronounced differences in B. Ascomycota, Basidiomycota, and Mortierellomycota were the main phyla found in the three cropping systems. Agaricomycetes and Sordariomycetes are the predominant classes in B, representing 23.8 and 22.4%, respectively, while Sordariomycetes (27.9%) followed by Eurotiomycetes (12.3%) were the predominant classes in V and Sordariomycetes (39.2%) followed by Tremellomycetes (8.9%) in the H. Saprotrophs are the fungal group showing higher relative abundance in the three cropping systems, followed by plant pathogens. Regarding symbionts, endophytes were highly observed in B, while mycorrhizal fungi was predominant in V and H. The structure of fungal communities was mainly correlated with soil content of P, K, N, Fe, and Cu. In addition, we identified bioindicators for each cropping system, which means that cultivated crops are also drivers of functional groups and the composition of communities. Overall, the three cropping systems favored diversity and growth of taxa that play important roles in soil, which highlights the importance of conservative management practices to maintain a healthy and resilient agrosystem.</jats:p>