562 research outputs found
Hybrid Sepic-Ćuk DC-DC Converter Associated to a SRM Drive for a Solar PV Powered Water Pumping System
Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2019 do Instituto Politécnico de Lisboa. Código de referência IPL/2019/SOLARPUMP_ISELThe present paper describes a solar photovoltaic (SPV) powered water pumping system employing a switched reluctance motor (SRM) and a merged Sepic-Ćuk DC-DC converter. The proposed solution was designed to use efficiently the available solar energy in order to supply water pumping systems. Solutions of this kind assume a special importance in the current scenario of natural and renewable resources optimization. The proposed DC-DC converter operates in continuous conduction mode (CCM), which combined with a maximum power point tracking (MPPT) controller, helps to optimize the power of the solar photovoltaic panel (SPV). The proposed DC-DC topology is characterized by high voltage static gain when compared with the classical boost topology and reduced voltage stress across the power switch and diodes. Several simulation and experimental results are presented in order to confirm the characteristics of the proposed solution for water pumping systems.info:eu-repo/semantics/publishedVersio
The Role of Gut Microbiota in the Etiopathogenesis of Multiple Chronic Diseases
Chronic diseases (CD) may result from a combination of genetic factors, lifestyle and social behaviours, healthcare system influences, community factors, and environmental determinants of health. These risk factors frequently coexist and interact with one another. Ongoing research and a focus on personalized interventions are pivotal strategies for preventing and managing chronic disease outcomes. A wealth of literature suggests the potential involvement of gut microbiota in influencing host metabolism, thereby impacting various risk factors associated with chronic diseases. Dysbiosis, the perturbation of the composition and activity of the gut microbiota, is crucial in the etiopathogenesis of multiple CD. Recent studies indicate that specific microorganism-derived metabolites, including trimethylamine N-oxide, lipopolysaccharide and uremic toxins, contribute to subclinical inflammatory processes implicated in CD. Various factors, including diet, lifestyle, and medications, can alter the taxonomic species or abundance of gut microbiota. Researchers are currently dedicating efforts to understanding how the natural progression of microbiome development in humans affects health outcomes. Simultaneously, there is a focus on enhancing the understanding of microbiome-host molecular interactions. These endeavours ultimately aim to devise practical approaches for rehabilitating dysregulated human microbial ecosystems, intending to restore health and prevent diseases. This review investigates how the gut microbiome contributes to CD and explains ways to modulate it for managing or preventing chronic conditions.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for
financial support by national funds FCT/MCTES CIMO (UIDB/00690/2020 and UIDP/00690/2020)
and SusTEC (LA/P/0007/2020); national funding by FCT, P.I., through the institutional scientific
employment program-contract for S.Heleno and R. Calhelha contracts.info:eu-repo/semantics/publishedVersio
Erratum: Moreira, J., et al., Spin-Coated Polysaccharide-Based Multilayered Freestanding Films with Adhesive and Bioactive Moieties. Molecules 2020, 25, 840
Erratum: Moreira, J., et al., Spin-Coated Polysaccharide-Based Multilayered Freestanding
Films with Adhesive and Bioactive Moieties. Molecules 2020, 25, 840. DOI: 10.3390/molecules25040840The authors wish to make changes to the published paper 11 j. 1. UV-Vis Analysis of Catechol-Modified Polymers In the original manuscript theie is a mistake concerning the word "Wavenumber" in the X-Coordinate in Figure 1. Tile corrected word is "Wavelength". Tlx- A uthors also wish to change mg«mL-l to mg ml-1 in the legend of Figure l;see corrected Figure 1 below. (Figure Presented).(undefined
Sleep quality of mother-caregivers of Duchenne muscular dystrophy patients
Background Sleep disturbance is a common problem for caregivers. In general, patients with Duchenne muscular dystrophy (DMD) use noninvasive ventilation to maintain quality of life and improve survival. Objective The aim of this study was to evaluate the sleep quality of caregiver-mothers of sons with DMD and factors that are associated with their sleep quality. Methods We evaluated 32 caregiver-mothers of sons with DMD and 32 mothers of sons without any neuromuscular or chronic disease (control-CTRL group). The evaluation of quality of sleep was made using the Pittsburgh Sleep Quality Index (PSQI). Results Caregiver-mothers had poor sleep quality, specifically longer sleep latency and reduced sleep efficiency. The impaired sleep quality of the caregiver-mothers was associated with the length of time of noninvasive ventilation used by their sons. Conclusions Our results suggest that caregiver-mothers of sons with DMD have poor quality of sleep, and the length of use of noninvasive ventilation of their sons is associated with better sleep of caregiver-mothers.Associacao Fundo de Incentivo a Pesquisa (AFIP)CAPESCNPqSao Paulo Research Foundation (FAPESP)Univ Fed Sao Paulo, Dept Psicobiol, Rua Napoleao Barros 925, BR-04024002 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Psicobiol, Rua Napoleao Barros 925, BR-04024002 Sao Paulo, SP, BrazilFAPESP: 2014/08067-0Web of Scienc
Double-layer force suppression between charged microspheres
In this paper we propose a protocol to suppress double-layer forces between two microspheres immersed in a dielectric medium, being one microsphere metallic at a controlled potential
ψ
M
and the other a charged one either metallic or dielectric. The approach is valid for a wide range of distances between them. We show that, for a given distance between the two microspheres, the double-layer force can be totally suppressed by simply tuning
ψ
M
up to values dictated by the linearized Poisson-Boltzmann equation. Our key finding is that such values can be substantially different from the ones predicted by the commonly used proximity force approximation, also known as the Derjaguin approximation, even in situations where the latter is expected to be accurate. The proposed procedure can be used to suppress the double-layer interaction in force spectroscopy experiments, thus paving the way for measurements of other surface interactions, such as Casimir dispersion forces
Pre-selection of fibroblasts subsets prompt prevascularization of tissue engineered skin analogues
The papillary and reticular dermis harbors phenotypically distinct fibroblasts, whose functions such as maintenance of skin's microvasculature are also distinct. Thus, we hypothesized that pre-selection of the subpopulations of fibroblasts would benefit the generation of skin tissue engineered (TE) constructs, promoting their prevascularization in vitro. We first isolated papillary and reticular fibroblasts using fluorescence-activated cell sorting and studied the effect of their secretome and extracellular matrix (ECM) on human dermal microvascular endothelial cell (hDMEC) organization. Subsequently, we developed a bilayered 3D polymeric structure with distinct layer-associated features to house the subpopulations of fibroblasts, to generate a skin analogue. Both papillary and reticular fibroblasts were able to stimulate capillary-like network formation in a Matrigel assay. However, the secretome of the two subpopulations was substantially different, being enriched in VEGF, IGF-1, and Angio-1 in the case of papillary fibroblasts and in HGF and FGF-2 for the reticular subset. In addition, the fibroblast subpopulations deposited varied levels of ECM proteins, more collagen I and laminin was produced by the reticular subset, but these differences did not impact hDMEC organization. Vessel-like structures with lumens were observed earlier in the 3D skin analogue prepared with the sorted fibroblasts, although ECM deposition was not affected by the cell's pre-selection. Moreover, a more differentiated epidermal layer was obtained in the skin analogue formed by the sorted fibroblasts, confirming that its whole structure was not affected. Overall, we provide evidence that pre-selection of papillary and reticular fibroblasts is relevant for promoting the in vitro prevascularization of skin TE constructs.The authors would like to acknowledge the financial support from the Consolidator Grant “ECM_INK” (ERC-2016- COG-726061), to the FSE/POCH (Fundo Social Europeu através do Programa Operacional do Capital Humano) under the scope of the PD/169/2013, NORTE-08-5369-FSE-000037 (H.R. M.)
Differences in the phenolic composition and nutraceutical properties of freeze dried and oven-dried wild and domesticated samples of Sanguisorba minor Scop
Recent studies have dealt about the phenolic compounds and the nutraceutical properties of Sanguisorba minor Scop and about the possibility of their domestication to standardise the plant production. However, it is also known that the storage conditions can affect the bioactive compounds present in plants. Thus, wild (W) and domesticated (F1, F2, F3) S. minor samples were exposed to different drying methods (oven-drying at 60 °C until constant weight named OD or freeze-drying until constant weight named FD) and studied for their content in phenolic compounds, antioxidant, antimicrobial, cytotoxic and anti-inflammatory properties. In general, OD samples showed the highest nutraceutical properties and the highest content in phenolic compounds. The most abundant phenolic compounds in both drying methods were kaempferol-3-O-glucoside and caffeoyl ester, with some differences between wild and domesticated samples. Wild samples showed higher antimicrobial and cytotoxic activity than domesticated ones, except for the OD F3 and FD F2 samples that reported cytotoxicity against HeLa cells. This study provides important information to choose the most adequate methodology to retain phenolic compounds and nutraceutical properties of S. minor species. Further researches are necessary to standardise the domestication of the studied wild species and verify the highest efficiency of the OD method.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/00690/2020). L. Barros and C.
Calhelha also thank the national funding by FCT – Foundation for Science
and Technology, P.I., through the institutional scientific employment
program-contract for their contracts, and Sandrina A. Heleno
thanks to the national funding by FCT, P.I., through the individual scientific
employment program-contract. The authors are also grateful to
FEDER-Interreg España-Portugal programme for financial support
through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P and to
European Regional Development Fund (ERDF) through the Regional
Operational Program North 2020, within the scope of Project Norte-01-
0145-FEDER-000042: GreenHealth.info:eu-repo/semantics/publishedVersio
Using simulation to model the logistic operations of a company of the cement industry
This paper presents a discrete-event simulation model to study the logistics operations involved in a plant of the cement industry, aligned with a real project developed in partnership between Cachapuz (a company that provides international weighing solutions) and the University of Minho. The purpose of this work consists in using simulation to model several activities, involving weighing, loading and unloading of raw materials, regardless of the type of industry, e.g. cement, tomato, cereals. Thus, this paper documents the work conducted to apply the developed simulation model in a case study of the cement industry. After validating the model, a set of simulation experiments were conducted, which allowed to estimate the maximum capacity of the plant and the impact in the performance of the plant, of the arrival of a cargo vessel. In this regard, it was found that in the case study in question, it is not possible to unload all the cargo from the vessel in a working day - around 3 working days would be required. Further conclusions and future work are discussed in the last section.- (undefined
Exploring the bioactive compounds from berry biowaste: Eugenia involucrata DC. as a study case
Aiming at valorising the Eugenia involucrata residue, the present work aimed in investigating the chemical profile and in vitro bioactivities of the residue (EIR) and its individual parts, i.e., seeds (EIS) and peels (EIP). Chromatographic analyses showed that EIP had the highest content of organic acids, tocopherols, and anthocyanins, whereas EIS was the richest in hydrolysable tannins. bis-HHDP-glucoside isomers and cyanidin-3-O-galactoside were the main detected phenolic compounds. By the cellular antioxidant activity (CAA) assay, the samples showed similar. antioxidant potential with 71%, 77%, and 80% inhibition for EIP, EIR, and EIS, respectively, while EIS demonstrated the best antioxidant activity by thiobarbituric acid reactive substances (TBARS, IC50 = 4.96 mu g/mL) and oxidative inhibition assay (OxHLIA, IC50 = 40 mu g/mL). The samples were able to inhibit the growth of seven bacteria and two fungi. Between the microorganisms tested, all samples showed a strong antibacterial activity (MIC = 0.156 mg/mL) against Yersinia enterocolitica and Pseudomonas aeruginosa (MIC = 0.156-0.625 mg/mL). Moreover, they also display a high antifungal activity against Arpergillus brasiliensis (MIC = 0.625 mg/mL). Furthermore, only EIR and EIS had anti-inflammatory effect via NO production inhibition (IC50 = 168-259 mu g/mL, respectively) and anti-proliferative activity towards four tumour and one non-tumour cell lines. These findings suggest that the biowaste generated during the processing of E. involucrata fruit has potential as a source of bioactive compounds.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2020) . To the "La Caixa" Foundation and to FCT for the financial support through the mobilizing Project "Aquae Vitae - Thermal water as a source of life and health", "PROMOVE - O futuro do Interior" call 2020. To FCT for the contracts of J. Pinela (CEECIND/01011/2018) , R.C. Calhelha and L. Barros (CEEC Institutional) , and the PhD grants of B.R. Albuquerque (SFRH/BD/136370/2018 and COVID/BD/152908/2022) . To the MICINN for the Juan de la Cierva Formacion contract for T.C.S.P. Pires (FJC20120- 045405-I) . R.C.G. Correa is a research grant recipient of Cesumar Institute of Science, Technology, and Innovation (ICETI) .info:eu-repo/semantics/publishedVersio
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