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Abstract The main objective of the present work was to highlight differences and similarities in gene expression patterns between different pluripotent stem cell cardiac differentiation protocols, using a workflow based on unsupervised machine learning algorithms to analyse the transcriptome of cells cultured as a 2D monolayer or as 3D aggregates. This unsupervised approach effectively allowed to portray the transcriptomic changes that occurred throughout the differentiation processes, with a visual representation of the entire transcriptome. The results allowed to corroborate previously reported data and also to unveil new gene expression patterns. In particular, it was possible to identify a correlation between low cardiomyocyte differentiation efficiencies and the early expression of a set of non-mesodermal genes, which can be further explored as predictive markers of differentiation efficiency. The workflow here developed can also be applied to analyse other stem cell differentiation transcriptomic datasets, envisaging future clinical implementation of cellular therapies.

Stryphnodendron pulcherrimum is a plant found in the Brazilian Amazon and contains high content of catechin/(epi)catechin (flavan-3-ol) derivatives. The polymerization of this kind of flavan-3-ol generates condensed tannins, often associated to plant-based diets and gut microbiota. Thus, the discovery of condensed tannins from plants is a valuable approach once it enhances their availability from natural sources. Herein, we described a tetrameric condensed tannin (Molecular Mass 1,170 a.m.u.) tentatively identified for the first time in the barks from S. pulcherrimum. Condensed tannins-derived (flavan-3-ols units) are likely degraded in the gut, and their degradation products such as 3-hydroxyphenylacetic acid (OPAC), 3,4-dihydroxyphenylacetic acid (DHAA), 3-(3,4-dihydroxyphenyl)-propionic acid (DHPA), and 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (DHPV) could present benefits to gut microbiome metabolism. Therefore, this observational study represents a new insight into S. pulcherrimum, its molecules, and their potential benefits to avoid different diseases and gut well-functional.

Direct Write Laser (DWL) Grayscale (GS) lithography has gathered attention as a versatile technological solution to fabricate arbitrary and complex 2.5D structures in photoresist (PR). In combination with Reactive Ion Etching (RIE), DWL GS can enable the fabrication of 2.5D micro-structured silicon substrates to be used as molds in high-precision replication processes. To this end, typically, a multilevel pattern is first defined in a low contrast PR and then transferred to the Si substrate via anisotropic RIE. The uniformity and selectivity of the etching process to the PR and substrate materials will define the dimensions of the 2.5D structures in the substrate. However, while there have been numerous examples of etched shapes in Si using this strategy, the wafer scale dimensional variations for etched Si molds fabricated via DWL GS and RIE have not been reported so far. In this work, we present a wafer-scale and wafer-to-wafer analysis of the dimensional variations in the fabrication process of Si molds with 2.5D 100-μm deep cavities using DWL GS lithography and RIE. The dimensional variations and deviations were characterized along each process step over several wafers. The final Si etched shapes consisting of microlens array cavities showed a maximum relative deviation of 10.35% with respect to the intended shape design with a curvature radius variation up to ∼5%, demonstrating this process potential for arbitrary 2.5D Si mold fabrication.

Water-based drilling fluids (WBDF) are often used over oil-based drilling fluids due to economic reasons and environmental regulations. Bentonite-free WBDF is preferred to aid in the reduction of formation damage. In many cases, this WBDF is formulated with xanthan gum. The performance of drilling operations is mainly affected by the drilling fluid formulation. The complex interactions among polymer concentration, thermal, and shear histories influence the rheological behavior of drilling fluids. The present study aims to analyze the effects of xanthan gum concentration on the rheological behavior of water-based drilling fluids. The experimental results performed in rotational rheometers revealed a relationship between concentration, yield stress, and thixotropic phenomena. The increase in xanthan gum concentration not only enhances the stability of the drilling fluid, allowing for more prolonged process interruptions without risking the fluid degradation but also improves the thermal stability of the sample. These findings show that the concentration of xanthan gum improves water-based drilling fluids' rheological and thermal stability. [ABSTRACT FROM AUTHOR]

Swietenia macrophylla King is a plant commonly known as Brazilian mahogany. The wood from its stem is highly prized for its exceptional quality, while its leaves are valued for their high content of phragmalin-type limonoids, a subclass of compounds known for their significant biological activities, including antimalarial, antitumor, antiviral, and anti-inflammatory properties. In this context, twelve isolated limonoids from S. macrophylla leaves were employed as standards in mass spectrometry-based molecular networking to unveil new potential mass spectrometry signatures for phragmalin-type limonoids. Consequently, ultra-performance liquid chromatography coupled with high-resolution mass spectrometry was utilized for data acquisition. Subsequently, the obtained data were analyzed using the Global Natural Products Social Molecular Networking platform based on spectral similarity. In summary, this study identified 24 new putative phragmalin-type limonoids for the first time in S. macrophylla. These compounds may prove valuable in guiding future drug development efforts, leveraging the already established biological activities associated with limonoids.

Diffractive lenses can replicate the optical functions of their refractive counterparts using an equivalent surface relief phase profile, enabling more compact optical assemblies and microsystem integration. Greyscale lithography enables the direct definition of tridimensional photoresist lenses atop glass substrates, providing a simple nanofabrication process for complex micro-optics, compatible with nanoimprint replication. In this work, we report the greyscale fabrication and optical characterization of 10 × 10 mm2, NA ≈ 0.25, photoresist diffractive lenses for near-infrared LIDAR applications and evaluate their optical performance in the visible range for imaging. We demonstrate a two-lens varifocal system integrating diffractive lenses for λ = 1550 nm operation with a 55–215 mm focal length tuning range and an average spot size of ø188 ± 82 μm. In addition, we characterize the strong longitudinal chromatic aberration, typical of diffractive lenses, and evaluate their optical performance for imaging in the visible range.

Objectives: Past suicide attempt (SA) is one of the most important risk factors for suicide death. An ideation-to-action framework posits that impulsivity, potentially traumatic events, and mental disorders also play a role in increasing suicide risk. This study aimed to assess the association between trait impulsivity, lifetime exposure to trauma, and post-traumatic stress disorder (PTSD) with SA in a sample of Brazilian college students. Methods: A total of 2,137 participants filled self-reported questionnaires consisting of a sociodemographic and clinical questionnaire, Trauma History Questionnaire, Post-Traumatic Stress Disorder Checklist – Civilian version, and Barratt Impulsiveness Scale. Results: Our findings suggest that trait impulsivity may be interpreted as exerting a distal effect on SA, even in the presence of other variables – such as trauma history, psychological neglect, and PTSD – which also increase the odds of SA. High and medium levels of impulsivity, history of trauma, and PTSD increased the likelihood of SA. Conclusions: Intervention strategies to prevent SA may target trait impulsivity and exposure to traumatic experiences.

Over recent years, the field of cell and gene therapy has witnessed rapid growth due to the demonstrated benefits of using living cells as therapeutic agents in a broad range of clinical studies and trials. Bioprocess economic models (BEMs) are fundamental tools for guiding decision-making in bioprocess design, being capable of supporting process optimization and helping to reduce production costs. These tools are particularly important when it comes to guiding manufacturing decisions and increasing the likelihood of market acceptance of cell-based therapies, which are often cost-prohibitive because of high resource and quality control costs. Not only this, but the inherent biological variability of their underlying bioprocesses makes them particularly susceptible to unforeseen costs arising from failed or delayed production batches. The present work reviews important concepts concerning the development of bioprocesses for stem cell therapy products and highlights the valuable role which BEMs can play in this endeavor. Additionally, some theoretical concepts relevant to the building and structuring of BEMs are explored. Finally, a comprehensive review of the existent BEMs so far reported in the scientific literature for stem cell-related bioprocesses is provided to showcase their potential usefulness.

Deguelia nitidula (Benth.) A.M.G.Azevedo & R.A.Camargo (Fabaceae) is an herbaceous plant distributed in the Brazilian Amazon, and it is called “raiz do sol” (sun roots). On Marajó Island, quilombola communities use its prepared roots to treat skin diseases commonly caused by fungi, viruses, and bacteria. Thus, in this study, the extract, and its fractions from D. nitidula roots were used to perform in vitro cytotoxic and antibacterial assays against Staphylococcus aureus strains. Thereafter, liquid chromatography–mass spectrometry (LC–MS) was used for the metabolite annotation process. The ethanolic extract of D. nitidula roots show significant bactericidal activity against S. aureus with IC50 82 μg.mL−1 and a selectivity index (SI) of 21.35. Furthermore, the SREFr2 and SREFr3 fractions show a potent bactericidal activity, i.e., MIC of 46.8 μg.mL−1 for both, and MBC of 375 and 93.7 μg.mL−1, respectively. As showcased, SREFr3 shows safe and effective antibacterial activity mainly in respect to the excellent selectivity index (SI = 82.06). On the other hand, SREFr2 shows low selectivity (SI = 6.8), which characterizes it as not safe for therapeutic use. Otherwise, due to a limited amount of reference MS2 spectra in public libraries, up to now, it was not possible to perform a complete metabolite annotation. Despite that, our antibacterial results for SREFr3 and correlated substructures of amino acid derivatives show that the roots of D. nitidula are a natural source of specialized metabolites, which can be isolated in the future, and then used as a support for further bio-guided research, as well as natural drug development.

Abstract Background Since their inception, human induced pluripotent stem cells (hiPSCs) have held much promise for pharmacological applications and cell-based therapies. However, their potential can only be realised if large numbers of cells can be produced reproducibly on-demand. While bioreactors are ideal systems for this task, due to providing agitation and control of the culture parameters, the common impeller geometries were not designed for the expansion of mammalian cells, potentially leading to sub-optimal results. Results This work reports for the first time the usage of the novel Vertical-Wheel single-use bioreactors for the expansion of hiPSCs as floating aggregates. Cultures were performed in the PBS MINI 0.1 bioreactor with 60 mL of working volume. Two different culture media were tested, mTeSR1 and mTeSR3D, in a repeated batch or fed-batch mode, respectively, as well as dextran sulfate (DS) supplementation. mTeSR3D was shown to sustain hiPSC expansion, although with lower maximum cell density than mTeSR1. Dextran sulfate supplementation led to an increase in 97 and 106% in maximum cell number when using mTeSR1 or mTeSR3D, respectively. For supplemented media, mTeSR1 + DS allowed for a higher cell density to be obtained with one less day of culture. A maximum cell density of (2.3 ± 0.2) × 106 cells∙mL− 1 and a volumetric productivity of (4.6 ± 0.3) × 105 cells∙mL− 1∙d− 1 were obtained after 5 days with mTeSR1 + DS, resulting in aggregates with an average diameter of 346 ± 11 μm. The generated hiPSCs were analysed by flow cytometry and qRT-PCR and their differentiation potential was assayed, revealing the maintenance of their pluripotency after expansion. Conclusions The results here described present the Vertical-Wheel bioreactor as a promising technology for hiPSC bioprocessing. The specific characteristics of this bioreactor, namely in terms of the innovative agitation mechanism, can make it an important system in the development of hiPSC-derived products under current Good Manufacturing Practices.

Momordica charantia L. (Cucurbitaceae) is a plant known in Brazil as “melão de São Caetano”, which has been related to many therapeutic applications in folk medicine. Herein, we describe antibacterial activities and related metabolites for an extract and fractions obtained from the leaves of that species. An ethanolic extract and its three fractions were used to perform in vitro antibacterial assays. In addition, liquid chromatography coupled to mass spectrometry and the molecular networking approach were used for the metabolite annotation process. Overall, 25 compounds were annotated in the ethanolic extract from M. charantia leaves, including flavones, terpenes, organic acids, and inositol pyrophosphate derivatives. The ethanolic extract exhibited low activity against Proteus mirabilis (MIC 312.5 µg·mL−1) and Klebsiella pneumoniae (MIC 625 µg·mL−1). The ethyl acetate phase showed interesting antibacterial activity (MIC 156.2 µg·mL−1) against Klebsiella pneumoniae, and it was well justified by the high content of glycosylated flavones. Therefore, based on the ethyl acetate phase antibacterial result, we suggest that M. charantia leaves could be considered as an alternative antibacterial source against K. pneumoniae and can serve as a pillar for future studies as well as pharmacological application against the bacteria.

In this work, the oxygen transport and hydrodynamic flow of the PBS Vertical-Wheel MINI™ 0.1 bioreactor were characterized using experimental data and computational fluid dynamics simulations. Data acquired from spectroscopy-based oxygenation measurements was compared with data obtained from 3D simulations with a rigid-lid approximation and LES-WALE turbulence modeling, using the open-source software OpenFOAM-8. The mass transfer coefficients were determined for a range of stirring speeds between 10 and 100 rpm and for working volumes between 60 and 100 mL. Additionally, boundary condition, mesh refinement, and temperature variation studies were performed. Lastly, cell size, energy dissipation rate, and shear stress fields were calculated to determine optimal hydrodynamic conditions for culture. The experimental results demonstrate that the kL can be predicted using Sh=1.68Re0.551Sc13G1.18, with a mean absolute error of 2.08%. Using the simulations and a correction factor of 0.473, the expression can be correlated to provide equally valid results. To directly obtain them from simulations, a partial slip boundary condition can be tuned, ensuring better near-surface velocity profiles or, alternatively, by deeply refining the mesh. Temperature variation studies support the use of this correlation for temperatures up to 37 °C by using a Schmidt exponent of 1/3. Finally, the flow was characterized as transitional with diverse mixing mechanisms that ensure homogeneity and suspension quality, and the results obtained are in agreement with previous studies that employed RANS models. Overall, this work provides new data regarding oxygen mass transfer and hydrodynamics in the Vertical-Wheel bioreactor, as well as new insights for air-water mass transfer modeling in systems with low interface deformation, and a computational model that can be used for further studies.

In vivo and in vitro cells rely on the support of an underlying biocompatible substrate, such as the extracellular matrix or a culture substrate, to spread and proliferate. The mechanical and chemical properties of such structures play a central role in the dynamical and statistical properties of the tissue. At the cell scale, these substrates are highly disordered. Here, we investigate how spatial heterogeneities of the cell-substrate interaction influence the motility of the cells in a model confluent tissue. We use the self-propelled Voronoi model and describe the disorder as a spatially dependent preferred geometry of the individual cells. We found that when the characteristic length scale of the preferred geometry is smaller than the cell size, the tissue is less rigid than its homogeneous counterpart, with a consequent increase in cell motility. This result is in sharp contrast to what has been reported for tissues with heterogeneity in the mechanical properties of the individual cells, where the disorder favors rigidity. Using the fraction of rigid cells, we observe a collapse of the motility data for different model parameters and provide evidence that the rigidity transition in the model tissue is accompanied by the emergence of a spanning cluster of rigid cells.

The Voronoi model is a popular tool for studying confluent living tissues. It exhibits an anomalous glassy behavior even at very low temperatures or weak active self-propulsion, and at zero temperature, the model exhibits a disordered solid structure with no evidence of a rigidity transition. Here, we investigate the properties of the energy landscape in this limit. We find that the structure of the energy landscape changes as a function of the preferred shape parameter of the cells p_{0}. We find two disordered solid phases that have similar structural features but differ in the ultrametricity of their energy landscapes; the crossover between these two states shares phenomenological properties with a Gardner transition. We further highlight how the metric used to calculate distances between configurations influences the ability to detect hierarchical arrangements of basins in the energy landscape.

Peperomia pellucida is a species known in the Amazon as “erva-de-jabuti” that has been used in several therapeutic applications based on folk medicine. Herein, we describe the classes, subclasses, and the main compounds of the leaves, stems, and roots from P. pellucida by ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry associated with molecular networks, mirror plot on the GNPS library, and machine learning. These data show compounds that were annotated for the first time in the Peperomia genus, such as 2′,4′,5′-trihydroxybutyrophenonevelutin, dehydroretrofractamide C, and retrofractamide B.

In Portugal, the dropout rate of university courses is around 29%. Understanding the reasons behind such a high desertion rate can drastically improve the success of students and universities. This work applies existing data mining techniques to predict the academic dropout mainly using the academic grades. Four different machine learning techniques are presented and analyzed. The dataset consists of 331 students who were previously enrolled in the Computer Engineering degree at the Universidade de Trás-os-Montes e Alto Douro (UTAD). The study aims to detect students who may prematurely drop out using existing methods. The most relevant data features were identified using the Permutation Feature Importance technique. In the second phase, several methods to predict the dropouts were applied. Then, each machine learning technique’s results were displayed and compared to select the best approach to predict academic dropout. The methods used achieved good results, reaching an F1-Score of 81% in the final test set, concluding that students’ marks somehow incorporate their living conditions.

Smart, sustainable and inclusive growth is the basis for European 2020 strategy, in which small and medium enterprises (SMEs) are considered the backbone of European countries economies. The present study aims to investigate the relationship between the main variables that characterises small knowledge intensive firms (SKIFs) and the importance of their business expenditure on research and development (BERD). To achieve this, European member states were analysed during the period between 2008 and 2012 using a clusters analysis. Through this study it is possible to conclude that countries that have high growth values on SKIFs also achieve growth in GDP and BERD.

Swietenia macrophylla King is a plant commonly known as Brazilian mahogany. The wood from its stem is highly prized for its exceptional quality, while its leaves are valued for their high content of phragmalin-type limonoids, a subclass of compounds known for their significant biological activities, including antimalarial, antitumor, antiviral, and anti-inflammatory properties. In this context, twelve isolated limonoids from S. macrophylla leaves were employed as standards in mass spectrometry-based molecular networking to unveil new potential mass spectrometry signatures for phragmalin-type limonoids. Consequently, ultra-performance liquid chromatography coupled with high-resolution mass spectrometry was utilized for data acquisition. Subsequently, the obtained data were analyzed using the Global Natural Products Social Molecular Networking platform based on spectral similarity. In summary, this study identified 24 new putative phragmalin-type limonoids for the first time in S. macrophylla. These compounds may prove valuable in guiding future drug development efforts, leveraging the already established biological activities associated with limonoids. [ABSTRACT FROM AUTHOR]

Introduction: This study describes the molecular profile and the potential antiviral activity of extracts from Phyllanthus brasiliensis, a plant widely found in the Brazilian Amazon. The research aims to shed light on the potential use of this species as a natural antiviral agent. Methods: The extracts were analysed using liquid chromatography–mass spectrometry (LC–MS) system, a potent analytical technique to discover drug candidates. In the meantime, in vitro antiviral assays were performed against Mayaro, Oropouche, Chikungunya, and Zika viruses. In addition, the antiviral activity of annotated compounds was predicted by in silico methods. Results: Overall, 44 compounds were annotated in this study. The results revealed that P. brasiliensis has a high content of fatty acids, flavones, flavan‐3‐ols, and lignans. Furthermore, in vitro assays revealed potent antiviral activity against different arboviruses, especially lignan‐rich extracts against Zika virus (ZIKV), as follows: methanolic extract from bark (MEB) [effective concentration for 50% of the cells (EC50) = 0.80 μg/mL, selectivity index (SI) = 377.59], methanolic extract from the leaf (MEL) (EC50 = 0.84 μg/mL, SI = 297.62), and hydroalcoholic extract from the leaf (HEL) (EC50 = 1.36 μg/mL, SI = 735.29). These results were supported by interesting in silico prediction, where tuberculatin (a lignan) showed a high antiviral activity score. Conclusions: Phyllanthus brasiliensis extracts contain metabolites that could be a new kick‐off point for the discovery of candidates for antiviral drug development, with lignans becoming a promising trend for further virology research. The study explores the antiviral activity of extracts from Phyllanthus brasiliensis against Mayaro, Oropouche, Chikungunya, and Zika viruses. A total of 44 compounds were annotated, including fatty acids, flavones, flavan‐3‐ols, and lignans. The lignan‐rich extracts showed potent antiviral activity, particularly against the Zika virus. In silico antiviral prediction suggested tuberculatin (a lignan) as a strong antiviral candidate. Hence, the study suggests that P. brasiliensis could be a promising source for the development of antiviral drugs, particularly those containing lignans. [ABSTRACT FROM AUTHOR]

The article discusses a study of patients with idiopathic inflammatory myopathies (II M) to examine the occurrence of mechanic's hands associated with interstitial lung disease (ILD). Topics discussed include manifestations of mechanic's hands, the analysis of mechanic's hands as predictor of ILD, and the presence of ILD, arthritis, mechanic's hands and cardiac involvement in patients positive with antisynthetase antibodies.

The control over the self-assembly of complex structures is a long-standing challenge of material science, especially at the colloidal scale, as the desired assembly pathway is often kinetically derailed by the formation of amorphous aggregates. Here, we investigate in detail the problem of the self-assembly of the three Archimedean shells with five contact points per vertex, i.e., the icosahedron, the snub cube, and the snub dodecahedron. We use patchy particles with five interaction sites (or patches) as model for the building blocks and recast the assembly problem as a Boolean satisfiability problem (SAT) for the patch–patch interactions. This allows us to find effective designs for all targets and to selectively suppress unwanted structures. By tuning the geometrical arrangement and the specific interactions of the patches, we demonstrate that lowering the symmetry of the building blocks reduces the number of competing structures, which in turn can considerably increase the yield of the target structure. These results cement SATassembly as an invaluable tool to solve inverse design problems. [ABSTRACT FROM AUTHOR]

Over recent years, the field of cell and gene therapy has witnessed rapid growth due to the demonstrated benefits of using living cells as therapeutic agents in a broad range of clinical studies and trials. Bioprocess economic models (BEMs) are fundamental tools for guiding decision-making in bioprocess design, being capable of supporting process optimization and helping to reduce production costs. These tools are particularly important when it comes to guiding manufacturing decisions and increasing the likelihood of market acceptance of cell-based therapies, which are often cost-prohibitive because of high resource and quality control costs. Not only this, but the inherent biological variability of their underlying bioprocesses makes them particularly susceptible to unforeseen costs arising from failed or delayed production batches. The present work reviews important concepts concerning the development of bioprocesses for stem cell therapy products and highlights the valuable role which BEMs can play in this endeavor. Additionally, some theoretical concepts relevant to the building and structuring of BEMs are explored. Finally, a comprehensive review of the existent BEMs so far reported in the scientific literature for stem cell-related bioprocesses is provided to showcase their potential usefulness. [ABSTRACT FROM AUTHOR]

O desenvolvimento de sistemas robóticos para cirurgia teve início na década de 80, por solicitação do exército norte-americano, que antevia a possibilidade de realizar operações em teatros de guerra, distantes do local onde estava o cirurgião. Entretanto, o primeiro uso em humanos só ocorreu anos mais tarde, numa ressecção transuretral de hiperplasia benigna de próstata. Cirurgiões cardíacos foram logo atraídos pela técnica robótica devido a possível aplicação com reduzido caráter invasivo; esperava-se menor trauma cirúrgico e redução da dor, morbidade, tempo de internação e custo do procedimento. Atualmente, de forma restrita e em casos selecionados, robôs são usados para revascularização do miocárdio e implante de marcapasso em cirurgias cardíacas totalmente endoscópicas; podendo também constituir apoio visual na retirada de artéria torácica interna, reconstrução valvar mitral e correção de defeitos congênitos. Utilizando o robô auxiliar AESOP® para controle do videotoracoscópio, com controle vocal por meio do sistema HERMES®, temos realizado dissecção da artéria torácica interna, implante de eletrodo ventricular esquerdo e abordagem de defeitos congênitos na cirurgia de correção. Apesar do entusiasmo científico inicial com a cirurgia robótica, ainda não existe evidência clara de superioridade desta técnica em relação à operação convencional, em termos de resultado. Isto se aplica também ao custo, pois o investimento inicial na aquisição de sistema cirúrgico completo (console, controle de vídeo, instrumental) provavelmente é compensado após muitos procedimentos e longo intervalo. Mas é certo que a cirurgia robótica terá um lugar no futuro, possibilitando aprendizagem, telepresença e realização de procedimentos pouco invasivos, embora complexos.The development of robotic systems for surgery started in the 80's, motivated by the US army's need for surgical procedure in field hospitals with surgeons in a distant location (tele-presence). But the first human application of robotic surgery occurred years later in a transurethral resection for benign prostatic hyperplasia. Cardiac surgeons were attracted to the robotic techniques because of the potential reduction in the invasive character of the procedures. This results in reduced trauma, a reduction of pain and morbidity, a faster recovery and lower cost of surgery. Robotic systems were developed, allowing totally thoracoscopic cardiac surgery for myocardial revascularization and multi-site pacemaker implantation in selected cases. Video-thoracoscopic support systems for internal thoracic artery harvesting, mitral valve reconstruction and correction of congenital heart defects also exist. We used the AESOP® system with HERMES® voice control to harvest the internal thoracic artery, trans-thoracic implantation of the left ventricular electrode and as an approach to congenital heart defects for surgical repair. In spite of scientific enthusiasm related to robotic surgery, there is no clear evidence of superiority of this technique when compared to conventional procedures in terms of results. The same is true with the cost of the procedures, and even if a single robotic surgery is less expensive, the initial investment for a complete robotic system (console, video control, instruments) can be compensated only with many procedures over the long term. But there is no doubt that robotic surgery will have a place in the future of surgery, providing tele-presence of the surgeon, enabling teaching and training and performing less invasive surgical procedures.

Deguelia nitidula (Benth.) A.M.G.Azevedo & R.A.Camargo (Fabaceae) is an herbaceous plant distributed in the Brazilian Amazon, and it is called "raiz do sol" (sun roots). On Marajó Island, quilombola communities use its prepared roots to treat skin diseases commonly caused by fungi, viruses, and bacteria. Thus, in this study, the extract, and its fractions from D. nitidula roots were used to perform in vitro cytotoxic and antibacterial assays against Staphylococcus aureus strains. Thereafter, liquid chromatography–mass spectrometry (LC–MS) was used for the metabolite annotation process. The ethanolic extract of D. nitidula roots show significant bactericidal activity against S. aureus with IC50 82 μg.mL−1 and a selectivity index (SI) of 21.35. Furthermore, the SREFr2 and SREFr3 fractions show a potent bactericidal activity, i.e., MIC of 46.8 μg.mL−1 for both, and MBC of 375 and 93.7 μg.mL−1, respectively. As showcased, SREFr3 shows safe and effective antibacterial activity mainly in respect to the excellent selectivity index (SI = 82.06). On the other hand, SREFr2 shows low selectivity (SI = 6.8), which characterizes it as not safe for therapeutic use. Otherwise, due to a limited amount of reference MS2 spectra in public libraries, up to now, it was not possible to perform a complete metabolite annotation. Despite that, our antibacterial results for SREFr3 and correlated substructures of amino acid derivatives show that the roots of D. nitidula are a natural source of specialized metabolites, which can be isolated in the future, and then used as a support for further bio-guided research, as well as natural drug development. [ABSTRACT FROM AUTHOR]

Momordica charantia L. (Cucurbitaceae) is a plant known in Brazil as "melão de São Caetano", which has been related to many therapeutic applications in folk medicine. Herein, we describe antibacterial activities and related metabolites for an extract and fractions obtained from the leaves of that species. An ethanolic extract and its three fractions were used to perform in vitro antibacterial assays. In addition, liquid chromatography coupled to mass spectrometry and the molecular networking approach were used for the metabolite annotation process. Overall, 25 compounds were annotated in the ethanolic extract from M. charantia leaves, including flavones, terpenes, organic acids, and inositol pyrophosphate derivatives. The ethanolic extract exhibited low activity against Proteus mirabilis (MIC 312.5 µg·mL−1) and Klebsiella pneumoniae (MIC 625 µg·mL−1). The ethyl acetate phase showed interesting antibacterial activity (MIC 156.2 µg·mL−1) against Klebsiella pneumoniae, and it was well justified by the high content of glycosylated flavones. Therefore, based on the ethyl acetate phase antibacterial result, we suggest that M. charantia leaves could be considered as an alternative antibacterial source against K. pneumoniae and can serve as a pillar for future studies as well as pharmacological application against the bacteria. [ABSTRACT FROM AUTHOR]

In this work, the oxygen transport and hydrodynamic flow of the PBS Vertical-Wheel MINI™ 0.1 bioreactor were characterized using experimental data and computational fluid dynamics simulations. Data acquired from spectroscopy-based oxygenation measurements was compared with data obtained from 3D simulations with a rigid-lid approximation and LES-WALE turbulence modeling, using the open-source software OpenFOAM-8. The mass transfer coefficients were determined for a range of stirring speeds between 10 and 100 rpm and for working volumes between 60 and 100 mL. Additionally, boundary condition, mesh refinement, and temperature variation studies were performed. Lastly, cell size, energy dissipation rate, and shear stress fields were calculated to determine optimal hydrodynamic conditions for culture. The experimental results demonstrate that the k L can be predicted using S h = 1.68 R e 0.551 S c 1 3 G 1.18 , with a mean absolute error of 2.08%. Using the simulations and a correction factor of 0.473, the expression can be correlated to provide equally valid results. To directly obtain them from simulations, a partial slip boundary condition can be tuned, ensuring better near-surface velocity profiles or, alternatively, by deeply refining the mesh. Temperature variation studies support the use of this correlation for temperatures up to 37 °C by using a Schmidt exponent of 1/3. Finally, the flow was characterized as transitional with diverse mixing mechanisms that ensure homogeneity and suspension quality, and the results obtained are in agreement with previous studies that employed RANS models. Overall, this work provides new data regarding oxygen mass transfer and hydrodynamics in the Vertical-Wheel bioreactor, as well as new insights for air-water mass transfer modeling in systems with low interface deformation, and a computational model that can be used for further studies. [ABSTRACT FROM AUTHOR]

In this article, a multiphysics simulation workflow based on the use of reduced-order models to decrease the computation time is presented. Using finite-element (FE) precomputed flux-linkage and lumped force lookup-tables in function of dq0 currents and rotor position, an electromagnetic model of a permanent-magnet synchronous machine (PMSM) is developed. Coupled to a mechanical state-space representation, the complete workflow allows to predict the vibrations of the motor. Using our model, the influence of the 0-sequence current on the vibration spectrum is investigated. A detailed description on the parameter identification for homogenized stator core of the considered 12-slot 10-pole delta-connected fractional-slot concentrated-winding spoke-type PMSM is also given. The numerical results are validated with experimental data for the machine at hand. Because of the large amount of FE data required, the workflow is best suited for the optimization of motor control schemes (instead of the initial design optimization) with the purpose of reducing the noise, vibration, and harshness. [ABSTRACT FROM AUTHOR]

Peperomia pellucida is a species known in the Amazon as "erva-de-jabuti" that has been used in several therapeutic applications based on folk medicine. Herein, we describe the classes, subclasses, and the main compounds of the leaves, stems, and roots from P. pellucida by ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry associated with molecular networks, mirror plot on the GNPS library, and machine learning. These data show compounds that were annotated for the first time in the Peperomia genus, such as 2′,4′,5′-trihydroxybutyrophenonevelutin, dehydroretrofractamide C, and retrofractamide B. [ABSTRACT FROM AUTHOR]

In Portugal, the dropout rate of university courses is around 29%. Understanding the reasons behind such a high desertion rate can drastically improve the success of students and universities. This work applies existing data mining techniques to predict the academic dropout mainly using the academic grades. Four different machine learning techniques are presented and analyzed. The dataset consists of 331 students who were previously enrolled in the Computer Engineering degree at the Universidade de Trás-os-Montes e Alto Douro (UTAD). The study aims to detect students who may prematurely drop out using existing methods. The most relevant data features were identified using the Permutation Feature Importance technique. In the second phase, several methods to predict the dropouts were applied. Then, each machine learning technique's results were displayed and compared to select the best approach to predict academic dropout. The methods used achieved good results, reaching an F1-Score of 81% in the final test set, concluding that students' marks somehow incorporate their living conditions. [ABSTRACT FROM AUTHOR]

Thixotropic yield stress materials show a shear-induced solid-liquid transition at the yielding point, characterized by yield stress and yield strain. It is well known in the literature that the elastic modulus and the yield stress of thixotropic materials increase with aging time. In the current work, we propose a discussion on the brittleness of a suspension of swollen bentonite in water, focusing mainly on the role of aging times on the yield strain and on the critical strain at the linear to nonlinear viscoelastic transition of the material. The yield strain was measured in creep and constant shear rate start-up experiments, whereas the linear to nonlinear viscoelastic transition was evaluated from Fourier transforms on transient data in oscillatory shear stress amplitude sweeps. We show that aging increases material brittleness since the yield strain decreases with the resting time. On the other hand, the linear to nonlinear viscoelastic transition strain is surprisingly unaffected by the aging process. Other thixotropic systems were also investigated: 8 and 10 wt. % suspensions of bentonite in water and a 2 wt. % suspension of Laponite® in tap water. These lead to similar observations, showing constant linear to nonlinear viscoelastic strains and decreasing yield strains over increasing aging times. These findings bring relevant information to the intricate open-discussion issue on how to describe the behavior of thixotropic materials below the yield stress. [ABSTRACT FROM AUTHOR]

The induced pluripotent stem cells (iPSCs) are derived from somatic cells by using reprogramming factors such as Oct4, Sox2, Klf4, and c-Myc (OSKM) or Oct4, Sox2, Nanog and Lin28 (OSNL). They resemble embryonic stem cells (ESCs) and have the ability to differentiate into cell lineage of all three germ-layer, including cardiomyocytes (CMs). The CMs can be generated from iPSCs by inducing embryoid bodies (EBs) formation and treatment with activin A, bone morphogenic protein 4 (BMP4), and inhibitors of Wnt signaling. However, these iPSC-derived CMs are a heterogeneous population of cells and require purification and maturation to mimic the in vivo CMs. The matured CMs can be used for various therapeutic purposes in regenerative medicine by cardiomyoplasty or through the development of tissue-engineered cardiac patches. In recent years, significant advancements have been made in the isolation of iPSC and their differentiation, purification, and maturation into clinically usable CMs. Newer small molecules have also been identified to substitute the reprogramming factors for iPSC generation as well as for direct differentiation of somatic cells into CMs without an intermediary pluripotent state. This review provides a concise update on the generation of iPSC-derived CMs and their application in personalized cardiac regenerative medicine. It also discusses the current limitations and challenges in the application of iPSC-derived CMs. [ABSTRACT FROM AUTHOR]

Research on human stem cells, such as pluripotent stem cells and mesenchymal stromal cells, has shown much promise in their use for regenerative medicine approaches. However, their use in patients requires large-scale expansion systems while maintaining the quality of the cells. Due to their characteristics, bioreactors have been regarded as ideal platforms to harbour stem cell biomanufacturing at a large scale. Specifically, single-use bioreactors have been recommended by regulatory agencies due to reducing the risk of product contamination, and many different systems have already been developed. This review describes single-use bioreactor platforms which have been used for human stem cell expansion and differentiation, along with their comparison with reusable systems in the development of a stem cell bioprocess for clinical applications. [ABSTRACT FROM AUTHOR]

This article deals with highlighting some pragmatic approaches for determining the key-parameters that one has to monitor in order not to jeopardize the fulfillment of the customer specifications, due to the tolerances, that occur in large-scale mass production. For that, two parametrization models (symmetric vs. asymmetric) and two types of parameter distributions (uniform vs. normal) are compared when considering lamination, stack assembly and material properties tolerances. Results in different scenarios for both the motor (in open-circuit and under load), and the whole drive (with and without position sensor detection errors) are provided and compared with end-of-line measurements (where available) for a 12-slots 10-poles IPM-type PMSM with fractional slot concentrated winding. After including the effect of the temperature in the full asymmetric model, rather good agreements between calculations and measurements are reported for back-EMF and torque constant. Furthermore, it is shown that the interaction between the uncertainties of the motor parameters and the rest of the drive's components (e.g. position sensor) cause large inaccuracies into the system, and they are hardly predictable by taking the individual deviations separately. Finally, towards the end, attempts are made to reduce the computational and the modeling effort using various techniques and ultimately fitted artificial neural networks (ANNs) as surrogates. [ABSTRACT FROM AUTHOR]

This work presents a flexible polyimide-based capacitive tactile sensing array with sub-millimeter spatial resolution. The sensor is conceived to be embedded in a multimodal artificial finger to detect and classify the texture morphology of an object’s surface. The proposed tactile sensor comprises a $16\times 16$ array of capacitive sensing units. Each unit is composed of a parallel square electrode pairs ($340~ {\mu }\text{m}\,\,\times 340~ {\mu }\text{m}$) separated by a compressible air cavity and embedded into a flexible polyimide substrate. Standard MEMS microfabrication techniques were used to develop the sensor. The polyimide device was covered with a thin compressible PDMS layer to tune the normal pressure sensitivity and dynamic range (225–430 ${\mu }\text{m}$ thin PDMS layer resulting in 0.23–0.14 fF/kPa). The detection of the surface morphologies of a regular grating stamp for different orientation and a small metallic nut placed on the sensor is demonstrated, showing a 420 ${\mu }\text{m}$ spatial resolution. The proposed sensor represents a novel capacitive tactile sensing device with a sub-mm resolution of human fingertip sensitivity. [ABSTRACT FROM AUTHOR]

A 1D MEMS (Micro-Electro-Mechanical Systems) mirror for LiDAR applications, based on vertically asymmetric comb-drive electrostatic actuators, is presented in this work employing a novel fabrication process. This novel micromachining process combines typical SOI-based bulk micromachining and grayscale lithography, enabling the fabrication of combs actuators with asymmetric heights using a single lithography step in the active layer. With this technique, the fabrication process is simplified, and the overall costs are reduced since the number of required lithography steps decrease. The fabricated mirrors present self-aligned electrodes with a $2.8~\mu \text{m}$ gap and asymmetric heights of the movable and the fixed electrodes of 20 $\mu \text{m}$ and 50 $\mu \text{m}$ , respectively. These asymmetric actuators are an essential feature for the operation mode of this device, enabling both in resonant and static mode operation. A mirror field of view (FOV) of 54° at 838 Hz was achieved under low-pressure, when resonantly operated, and a FOV of 0.8° in the static mode. [ABSTRACT FROM AUTHOR]

[Display omitted] • A tetrameric condensed tannin of (epi)catechin-(epi)gallocatechin was described for the first time in the barks from Stryphnodendron pulcherrimum. • Condensed tannins have many potentials to avoid human diseases. • Metabolized products (e.g., OPAC, DHAA, DHPA, and DHPV) from condensed tannins could be associated with the gut well-functional. Stryphnodendron pulcherrimum is a plant found in the Brazilian Amazon and contains high content of catechin/(epi)catechin (flavan-3-ol) derivatives. The polymerization of this kind of flavan-3-ol generates condensed tannins, often associated to plant-based diets and gut microbiota. Thus, the discovery of condensed tannins from plants is a valuable approach once it enhances their availability from natural sources. Herein, we described a tetrameric condensed tannin (Molecular Mass 1,170 a.m.u.) tentatively identified for the first time in the barks from S. pulcherrimum. Condensed tannins-derived (flavan-3-ols units) are likely degraded in the gut, and their degradation products such as 3-hydroxyphenylacetic acid (OPAC), 3,4-dihydroxyphenylacetic acid (DHAA), 3-(3,4-dihydroxyphenyl)-propionic acid (DHPA), and 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (DHPV) could present benefits to gut microbiome metabolism. Therefore, this observational study represents a new insight into S. pulcherrimum , its molecules, and their potential benefits to avoid different diseases and gut well-functional. [ABSTRACT FROM AUTHOR]