Classification PDO olive oils on the basis of their sterol composition by multivariate analysis

The sterol compositions (GLC/FID/capillary column) of monovarietal olive oils (51 samples) from the most important cultivars of northeastern Portugal (Cvs. Cobranc¸osa, Madural and Verdeal Transmontana) and 27 commercial samples of olive oils with protected denomination of origin (PDO) from the same region and cultivars were evaluated. Δ-sitosterol, Δ5-avenasterol and campesterol were the most representative sterols. Cholesterol, stigmasterol, clerosterol and Δ7-stigmastenol were also found in all samples. All studied samples respected EC Regulation N. 2568, and in all cases total sterols were remarkably higher than the minimum limit set by legislation, ranging from 2003 to 2682 mg/kg. Results were analysed with the help of several statistical techniques, including reduction of dimensionality by principal component analysis with cross-validation of the number of components, followed by the use of canonical variate predictive biplots for model development and canonical variate interpolative biplots for approximate classification of monovarietal and PDO olive oils. These biplots proved to be a very interesting solution in the present case study, overcoming the problems of interpretation and classification that arise whenever different multivariate analyses are coupled together

Multihierarchical electrodes based on titanate nanotubes and zinc oxide nanorods for photoelectrochemical water splitting

Studies involving water splitting to form hydrogen and oxygen have attracted attention because H2 is considered the fuel of the future. Photoelectrocatalysts have been widely used for this application, and several metal oxides can be applied as catalysts. Among them, we highlight zinc oxide nanorods (ZnONRs) and titanate nanotubes (TiNTs); however, their individual nanostructures exhibit disadvantages. For example, ZnONR shows rapid recombination of the photogenerated charges, and TiNT gives rise to randomly orientated films; these disadvantages limit their application as photoanodes. In this study, for the first time, we present a new class of multihierarchical electrodes based on TiNT-decorated ZnONR films that exhibited superior results to the individual species. The TiNTs are homogenously dispersed over the surface of the rods without forming agglomerates, giving rise to a heterojunction that exhibits lower recombination rates. It was found that the results are better when the contents of TiNT in the electrode are higher; thus, glycine was successfully used as a bridge to link both of the structures, increasing the amount of TiNT decorating the rods. As a result, the photocurrent generated with these multihierarchical electrodes is higher than that obtained for pure ZnONR electrodes (0.9 mA and 0.45 mA, respectively), and the electrode potentials for O2 evolution is lower than that observed for pure TiNT electrodes (0 V and 0.8 V vs. ERHE, respectively). The IPCE values are also higher for the multihierarchical electrodes

APRENDIZAGEM DE FÍSICA NO ENSINO MÉDIO POR MEIO DO PEER INSTRUCTION

The classical method of exhibition classes has some limitations, compared to the new teaching methodologies that are emerging. The Peer Instruction is an active methodology of physics teaching, which with the advancement of technology in the current times, has been increasingly used in classrooms, differentiating from the exhibition activities that are a classic mode of classes of all disciplines. In this work, the proposal of "The Peer instruction" is to envolve technologies, interaction, dialogue between students and teachers, and there is also na exchange of knowledge between all members of the room. This method was created in the United States by a professor at the Physics at Harvard University in 1990[04], in order to improve the students' learning during classes. To verify this learning, it was implemented a voting system among students, from an application of smarthphone[01], and according to the frequency of hits, would arrive at a time in class where groups will be trained to discuss the theme proposed by the teacher in classroom, and this is the moment by which the active teaching methodology was created, in addition to showing its effectiveness in teaching physics. Compared to the classic model of we will show that the method is also more efficient in certain cases[02].O método clássico de aulas expositivas possui algumas limitações, em comparação às novas metodologias de ensino que vem surgindo. O Peer Instruction (inglês para instruções por pares) é uma metodologia ativa de ensino de física, que com o avanço da tecnologia nos tempos atuais, vem sendo cada vez mais usados em salas de aula, diferenciando-se das atividades expositivas que são um modo clássico de aulas de todas as disciplinas. Nesse trabalho, a proposta do “O Peer instruction” é envolver tecnologias, interação, diálogo entre alunos e professores, e também há uma troca de conhecimentos entre todos os integrantes de sala. Com o intuito de melhorar a aprendizagem dos alunos durante as aulas, foi implementado um sistema de votação entre os alunos, a partir de um aplicativo de smartphone, para poder verificar a porcentagem de acertos da turma, e de acordo com a frequência de acertos, chegaria em um momento da aula em que irá ocorrer a formação de grupos para a discussão do tema proposto pelo professor em sala de aula, sendo que esse é o momento pelo qual foi criado a metodologia ativa de ensino, além de mostrar sua eficácia no ensino de física. Em comparação com o modelo clássico de ensino, iremos mostrar que o método também é mais eficiente em certos casos

Zeros of the Partition Function and Pseudospinodals in Long-Range Ising Models

The relation between the zeros of the partition function and spinodal critical points in Ising models with long-range interactions is investigated. We find the spinodal is associated with the zeros of the partition function in four-dimensional complex temperature/magnetic field space. The zeros approach the real temperature/magnetic field plane as the range of interaction increases.Comment: 20 pages, 9 figures, accepted to PR

Establishing the design space of a filtration-based operation for the concentration of human pluripotent stem cells

Stem cell manufacturing is often very challenging due to the complexity of the biological system. Quality-by-design (QbD), a risk-based framework based on relating process parameters and product quality, can cope with such complexity in process design [1] aiding to develop robust and reproducible unit operations. This work describes a shortcut approach for the design of tangential flow filtration for the concentration of human induced pluripotent stem cells (hiPSC), supported by design of experiments (DoE) approach. First, critical quality attributes (CQA), corresponding to the characteristics that ensure the final product quality, and critical process parameters (CPP), which directly affect cells’ CQA, are identified. Thereafter, a design space is developed, studying how a range of variability in CPP allows to achieve CQA [2]. Thus, CPP of shear rate, permeate flux and cell load were considered, and initially their impact on hiPSC recovery yield and viability responses was studied. A full factorial design confirmed significant interaction effects between all CPP, affecting both responses. The developed statistical model predicted that high shear rate (3000 s-1), permeate flux (250 LMH) and medium cell load (2 x 106 cell/cm2) would maximize both cell recovery yield and viability, where over 80% of hiPSC would be recovered after a volume reduction factor of 20 with high viability (over 93%). Such conditions were validated experimentally, and by performing a robustness analysis, the success rate of these operating conditions was assessed (65 - 70%). A parametric study was then conducted, identifying that increasing the shear rate (up to 3370 s-1) allowed to achieve the specified requirements for cell recovery yield (\u3e 80%) and viability (\u3e 90%) in 100% of the cases and no impact in hiPSC’s CQA in terms of identity, proliferation capacity and pluripotency was observed. References [1] Lipsitz YY et al, Nat. Biotechnol. 2016, 34, 393–400. [2] Food and Drug Administration, Guidance for Industry: Q8(R2) pharmaceutical development. The authors acknowledge iNOVA4Health Research Unit (LISBOA-01-0145-FEDER-007344), and Fundação para a Ciência e Tecnologia (FCT, Portugal) for funding the project CARDIOSTEM (MITP-TB/ECE/0013/2013), and the grants SFRH/BD/51940/2012 (MIT-Portugal), SFRH/BD/51573/2011

Nutritional composition and bioactivity of Umbilicus rupestris (Salisb.)Dandy: An underexploited edible wild plant

The inclusion of edible wild plants in human diet has been receiving an increasing attention, as they represent an easily accessible source of nutrients, vitamins and antioxidants. In this work, the leaves of Umbelicus rupestris (Salisb.) Dandy, an edible species for which only scarce data is available in literature, were thoroughly evaluated for its nutritional profile, chemical characterization and bioactive properties. Being considered a succulent plant, the leaves revealed a very high content of moisture, with several beneficial compounds, including omega-3 polyunsaturated fatty acids, tocopherols and different polyphenols. A total of twelve flavonoids, three phenolic acids and one phenylpropanoid glucoside were identified in the decoction and/or hydroethanolic extracts, with most of them being described for the first time in this plant. Both extracts showed antioxidant activity and potential to inhibit some of the assayed bacteria, while not presenting cytotoxic effects on a non-tumour primary cell culture.The authors are grateful to the Foundation for Science and Technology FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019). L. Barros, R.C. Calhelha, and A. Fernandes thank national funding by FCT, P.I., through the institutional scientific employment program-contract. For their contracts. This work was also funded by FEDER-Interreg España- Portugal programme through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

A link between the accumulation of DNA damage and loss of multi-potency of human mesenchymal stromal cells

Human mesenchymal stromal cells (hMSCs) represent an attractive cell source for clinic applications. Besides being multi-potent, recent clinical trials suggest that they secrete both trophic and immunomodulatory factors, allowing allogenic MSCs to be used in a wider variety of clinical situations. The yield of prospective isolation is however very low, making expansion a required step toward clinical applications. Unfortunately, this leads to a significant decrease in their stemness. To identify the mechanism behind loss of multi-potency, hMSCs were expanded until replicative senescence and the concomitant molecular changes were characterized at regular intervals. We observed that, with time of culture, loss of multi-potency was associated with both the accumulation of DNA damage and the respective activation of the DNA damage response pathway, suggesting a correlation between both phenomena. Indeed, exposing hMSCs to DNA damage agents led to a significant decrease in the differentiation potential. We also showed that hMSCs are susceptible to accumulate DNA damage upon in vitro expansion, and that although hMSCs maintained an effective nucleotide excision repair activity, there was a progressive accumulation of DNA damage. We propose a model in which DNA damage accumulation contributes to the loss of differentiation potential of hMSCs, which might not only compromise their potential for clinical applications but also contribute to the characteristics of tissue agein

The role of natural regeneration to ecosystem services provision and habitat availability: a case study in the Brazilian Atlantic Forest

Natural regeneration provides multiple benefits to nature and human societies, and can play a major role in global and national restoration targets. However, these benefits are context specific and impacted by both biophysical and socioeconomic heterogeneity across landscapes. Here we investigate the benefits of natural regeneration for climate change mitigation, sediment retention and biodiversity conservation in a spatially explicit way at very high resolution for a region within the global biodiversity hotspot of the Atlantic Forest. We classified current land-use cover in the region and simulated a natural regeneration scenario in abandoned pasturelands, areas where potential conflicts with agricultural production would be minimized and where some early stage regeneration is already occurring. We then modelled changes in biophysical functions for climate change mitigation and sediment retention, and performed an economic valuation of both ecosystem services. We also modelled how land-use changes affect habitat availability for species. We found that natural regeneration can provide significant ecological and social benefits. Economic values of climate change mitigation and sediment retention alone could completely compensate for the opportunity costs of agricultural production over 20 years. Habitat availability is improved for three species with different dispersal abilities, although by different magnitudes. Improving the understanding of how costs and benefits of natural regeneration are distributed can be useful to design incentive structures that bring farmers’ decision making more in line with societal benefits. This alignment is crucial for natural regeneration to fulfil its potential as a large-scale solution for pressing local and global environmental challenges

Model for a Universe described by a non-minimally coupled scalar field and interacting dark matter

In this work it is investigated the evolution of a Universe where a scalar field, non-minimally coupled to space-time curvature, plays the role of quintessence and drives the Universe to a present accelerated expansion. A non-relativistic dark matter constituent that interacts directly with dark energy is also considered, where the dark matter particle mass is assumed to be proportional to the value of the scalar field. Two models for dark matter pressure are considered: the usual one, pressureless, and another that comes from a thermodynamic theory and relates the pressure with the coupling between the scalar field and the curvature scalar. Although the model has a strong dependence on the initial conditions, it is shown that the mixture consisted of dark components plus baryonic matter and radiation can reproduce the expected red-shift behavior of the deceleration parameter, density parameters and luminosity distance.Comment: 11 pages and 6 figures. To appear in GR

A versatile capillary gel electrophoresis methodology for in-process and final product characterization of virus-based targets

The biopharmaceutical industry is approaching a turning point where new therapeutic modalities such as virus-based biopharmaceuticals are used in several applications such as vaccination, gene therapy and oncolytic therapy. However, the bioprocess of functional viruses still presents challenges, namely due to the availability of suitable analytics for downstream processing monitoring or characterization of the final product. Capillary electrophoresis (CE) is a versatile technique that enables the determination of intact or reduced particle number and the quantification of several product-related impurities, such as host cell DNA and host cell proteins. Although this f platform is commonly used for purity profiling of monoclonal antibodies in the pharmaceutical industry by ultraviolet (UV) detection, it requires a large amount of product, making it not suitable for virus-based pharmaceuticals, where total protein concentration (dose) is relatively low. This work presents a highly sensitive CE methodology for monitoring different bioprocess steps and final product characterization of several viral vectors. A fluorescence labelling procedure using the (3-(2-furoyl) quinoline-2-carboxaldehyde dye was used, enabling the detection of the viral proteins through Sodium dodecyl sulfate-capillary gel electrophoresis (CE-SDS) method coupled to a laser-induced fluorescence (LIF) detector. Please click Download on the upper right corner to see the full abstract