658 research outputs found

    Bioinformática: uma lista de recursos disponíveis

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    Enquanto temos a compreensão básica do funcionamento do gene quando codifica sequencias de proteínas especificas, sente-se a falta de informação relativa ao papel que 0 ADN tem em doenças especificas ou nas funções de milhares de proteínas que são produzidas. Os métodos utilizados na recolha, armazenamento, identificação, analise e correlação desta imensa e complexa informação , estão reunidos numa área científica designada por bioinformática

    Engineering immunomodulatory hydrogels and cell-laden systems towards bone regeneration

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    The well-known synergetic interplay between the skeletal and immune systems has changed the design of advanced bone tissue engineering strategies. The immune system is essential during the bone lifetime, with macrophages playing multiple roles in bone healing and biomaterial integration. If in the past, the most valuable aspect of implants was to avoid immune responses of the host, nowadays, it is well-established how important are the crosstalks between immune cells and bone-engineered niches for an efficient regenerative process to occur. For that, it is essential to recapitulate the multiphenotypic cellular environment of bone tissue when designing new approaches. Indeed, the lack of osteoimmunomodulatory knowledge may be the explanation for the poor translation of biomaterials into clinical practice. Thus, smarter hydrogels incorporating immunomodulatory bioactive factors, stem cells, and immune cells are being proposed to develop a new generation of bone tissue engineering strategies. This review highlights the power of immune cells to upgrade the development of innovative engineered strategies, mainly focusing on orthopaedic and dental applications.publishe

    An immunomodulatory miniaturized 3D screening platform using liquefied capsules

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    A critical determinant of successful clinical outcomes is the host's response to the biomaterial. Therefore, the prediction of the immunomodulatory bioperformance of biomedical devices following implantation is of utmost importance. Herein, liquefied capsules are proposed as immunomodulatory miniaturized 3D platforms for the high-content combinatorial screening of different polymers that could be used generically in scaffolds. Additionally, the confined and liquefied core of capsules affords a cell-mediated 3D assembly with bioinstructive microplatforms, allowing to study the potential synergistic effect that cells in tissue engineering therapies have on the immunological environment before implantation. As a proof-of-concept, three different polyelectrolytes, ranging in charge density and source, are used. Poly(L-lysine)-, alginate-, and chitosan-ending capsules with or without encapsulated mesenchymal stem/stromal cells (MSCs) are placed on top of a 2D culture of macrophages. Results show that chitosan-ending capsules, as well as the presence of MSCs, favor the balance of macrophage polarization toward a more regenerative profile, through the up-regulation of anti-inflammatory markers, and the release of pro-regenerative cytokines. Overall, the developed system enables the study of the immunomodulatory bioperformance of several polymers in a cost-effective and scalable fashion, while the paracrine signaling between encapsulated cells and the immunological environment can be simultaneously evaluated.publishe

    Viscous microcapsules as microbioreactors to study mesenchymal stem/stromal cells osteolineage commitment

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    It is essential to design a multifunctional well-controlled platform to transfermechanical cues to the cells in different magnitudes. This study introduces aplatform, a miniaturized bioreactor, which enables to study the effect of shearstress in microsized compartmentalized structures. In this system, thewell-established cell encapsulation system of liquefied capsules (LCs) is usedas microbioreactors in which the encapsulated cells are exposed to variablecore viscosities to experience different mechanical forces under a 3D dynamicculture. The LC technology is joined with electrospraying to produce suchmicrobioreactors at high rates, thus allowing the application of microcapsulesfor high-throughput screening. Using this platform for osteogenicdifferentiation as an example, shows that microbioreactors with higher coreviscosity which produce higher shear stress lead to significantly higherosteogenic characteristics. Moreover, in this system the forces experienced bycells in each LC are simulated by computational modeling. The maximum wallshear stress applied to the cells inside the bioreactor with low, and high coreviscosity environment is estimated to be 297 and 1367 mPa, respectively, forthe experimental setup employed. This work outlines the potential of LCmicrobioreactors as a reliable in vitro customizable platform with a wide rangeof applications.publishe

    Cell encapsulation in liquified compartments: Protocol optimization and challenges

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    Cell encapsulation is a widely used technique in the field of Tissue Engineering and Regenerative Medicine (TERM). However, for the particular case of liquefied compartmentalised systems, only a limited number of studies have been reported in the literature. We have been exploring a unique cell encapsulation system composed by liquefied and multilayered capsules. This system transfigured the concept of 3D scaffolds for TERM, and was already successfully applied for bone and cartilage regeneration. Due to a number of appealing features, we envisage that it can be applied in many other fields, including in advanced therapies or as disease models for drug discovery. In this review, we intend to highlight the advantages of this new system, while discussing the methodology, and sharing the protocol optimization and results. The different liquefied systems for cell encapsulation reported in the literature will be also discussed, considering the different encapsulation matrixes as core templates, the types of membranes, and the core liquefaction treatments.publishe

    Anxiety and social support as predictors of student academic motivation during the COVID-19

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    In this study we examined whether parents’ perceptions of students’ anxiety as well as perceived support from both teachers and classmates were predictive of changes in students’ academic motivation during the first wave of COVID-19. To this end, we used a retrospective pretest-posttest design together with a latent change score model to analyze our data. From April to May of 2020, 394 Portuguese parents of students in grades 1–9 participated in this study. Our results showed that students’ anxiety and teachers’ social support, as perceived by parents, were highly significant predictors of academic motivation changes. Specifically, we found a negative effect of anxiety and a positive effect of teachers’ social support on students’ academic motivation. Our results did not show, however, a significant predictive role of classmates’ social support. This study provides an important contribution to further understand the intrapersonal and interpersonal factors that are associated with the decline of students’ academic motivation during the COVID-19 pandemic. The pivotal role of teachers in sustaining students’ academic motivation and other relevant educational implications for the ongoing pandemic are discussed

    Production of curcumin from ferulic acid by an engineered Saccharomyces cerevisiae

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    II Congress in Health Sciences Research: Towards Innovation and Entrepreneurship - Trends in Biotechnology for Biomedical ApplicationsCurcumin is a secondary metabolite produced in the rhizome of Curcuma longa that represents the most active and studied naturally-derived curcuminoid product. Studies have confirmed its biological and therapeutic effects in several diseases being the anticancer activity the most documented. Since curcumin is synthetized in low amounts, its heterologous production could represent a rapid and easy method to obtain large amounts of this bioactive compound. Curcumin has already been produced in engineered Escherichia coli although with low yields. However, the curcumin biosynthetic pathway has never been engineered in Saccharomyces cerevisiae. As a eukaryotic organism, it presents unique advantages over E. coli that facilitate the expression of plant derived genes. This work aimed to design an artificial biosynthetic pathway for the production of curcumin by S. cerevisiae. The principal enzymes involved in the artificial pathway are: 4-coumarate-CoA ligase (4CL) and the type III polyketide synthases (PKSs). In C. longa there are two types of PKSs - diketide-CoA (DCS) and curcumin synthase (CURS) - that catalyse different reactions. Curcuminoid synthase (CUS) from Oryza sativa is also a PKS able of catalysing the one-pot synthesis of curcuminoids in E. coli. Herein, we intended to produce curcumin using ferulic acid as precursor. For that purpose, shuttle vectors with enzymes from different organisms were constructed and transformed in S. cerevisiae CENPK2-1C. The vectors carry 4CL from Arabidopsis thaliana or Lithospermum erythrorhizon, and DCS and CURS or CUS. DCS and CURS were codon-optimized for S. cerevisiae. In addition, CRISPRCas9 method was used to knockout a gene from S. cerevisiae that codifies ferulic acid decarboxylase that is responsible for the ferulic acid decarboxylation as a detoxification process. The engineered strains are currently being tested for curcumin production.info:eu-repo/semantics/publishedVersio

    Microlenses for stereoscopic image formation

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    This paper presents microlenses for integration on a stereoscopic image sensor in CMOS technology for use in biomedical devices. It is intended to provide an image sensor with a stereoscopic vision. An array of microlenses potentiates stereoscopic vision and maximizes the color fidelity. An array of optical filters tuned at the primary colors will enable a multicolor usage. The material selected for fabricating the microlens was the AZ4562 positive photoresist. The reflow method applied to the photoresist allowing the fabrication of microlenses with high reproducibility.This work was fully supported by the Portuguese Foundation for Science and Technology under the project FCT/PTDC/EEA-ELC/109936/2009

    Rice industry residues potential for curcumin production by engineered Saccharomyces cerevisiae

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    The use of curcumin, a polyphenol derived from turmeric, as a fighting cancer drug has been raising significant interest. However, obtaining curcumin-rich preparations can be challenging, and its microbial production provides a promising solution. The use of microorganisms comprises low-cost cultivation methods and fast production cycles. To this end, we have developed an engineered Saccharomyces cerevisiae strain that can produce curcumin from simple carbon sources. Curcumin biosynthesis requires several enzymatic steps, including reactions catalyzed by the phenylpropanoid pathway and by type III polyketide enzymes, none of them naturally present in yeast. To enable curcumin production, we introduced the necessary genes into the S. cerevisiae genome and confirmed the de novo production of curcumin using standard media. Rice production is a major global food industry, and its processing generates large amounts of non-food biomass. Rice residues are rich in cellulose polymer, which can be broken down to obtain free glucose. Our aim is to use extracts from rice residues as the substrate to produce curcumin with our engineered yeast. These extracts also contain intermediates of the curcumin pathway such as ferulic acid, which can enhance curcumin biosynthesis. We performed hydrolysis on rice husk and bran residues to obtain the extracts and quantified the presence of carbon sources, fermentation inhibitors, and curcumin precursors in both extracts. We are currently using these extracts in yeast fermentation for curcumin production.info:eu-repo/semantics/publishedVersio

    Fire behaviour of reinforced concrete slab strips strengthened with prestressed NSM-CFRP laminates

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    Carbon fibre reinforced polymer (CFRP) composites are now widely used to strengthen reinforced concrete (RC) structures. Among the strengthening systems available, near-surface mounted (NSM)-prestressed CFRP laminates offer several advantages, as they significantly increase the load carrying capacity and also the serviceability performance of RC structures. However, as for other CFRP systems, there is a concern about their behaviour at elevated temperature and under fire exposure due to the glass transition process undergone by their polymeric components. Nevertheless, the fire performance of NSM-prestressed-CFRP strengthening systems has not yet been investigated. This paper presents an experimental study about the fire resistance behaviour of RC slab strips strengthened with prestressed NSM-CFRP laminates; the slabs were simultaneously subjected to a mechanical (fire) load and the ISO 834 fire curve, and the influence of the following parameters on their fire resistance behaviour was assessed: (i) the prestress level (0 %, 25 % and 50 % of the CFRP tensile strength), and (ii) the presence of passive fire protection, comprising up to 48 mm thick calcium silicate (CS) boards. The results obtained showed that: (i) without fire protection, the strengthening system remained effective during a very low period of fire exposure, which significantly decreased with the prestress level, from 16 min (0 %) to less than 5 min (50 %); (ii) with fire protection, even with 50 % of prestress, the strengthening system remained effective for more than 120 min; and (iii) the “critical” temperatures in the anchorages of the strengthening systems were found to be about 2.5Tg, 2.0Tg and 1.5Tg, for the prestress levels of 0 %, 25 % and 50 %, respectively, with Tg being the glass transition temperature of the adhesive.The authors wish to acknowledge FCT (project FireComposite PTDC/ECM-EST/1882/2014 and CERIS project UIDB UIDB/04625/2020); Secil and Unibet˜ao for supplying the concrete; and S&P Clever Reinforcement for supplying the CFRP laminates and the epoxy adhesive. The first author also wishes to thank the financial support of FCT through the scholarship SFRH/BD/145256/2019
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