81 research outputs found

    Effect of moderate hydrostatic pressures on the enzymatic activity and bioactive composition of pineapple by-products

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    Special Issue Original ArticleThe application of abiotic stresses by moderate hydrostatic pressures (MHP) is still underdeveloped. Abiotic stresses allow activating the enzymatic complexes inducing the synthesis of de novo bioactive compounds. Pineapple by-products are rich in bromelain and bioactive compounds that can be enhanced through abiotic stresses. The aim of this study was to evaluate the effect of MHP on the enzymatic activity of pineapple by-products. Pineapple by-products were submitted to MHP (50–400 MPa between 1 and 15 min) according to a central composite factorial design matrix. Samples were stored at 5 ± 1 C for 24 hr, to allow enzymatic activity to occur. Enzymatic and antioxidant activities and total phenolic compounds (TPC) were quantified. MHP promoted a 262% increase in the phenylalanine ammonia-lyase activity and 36% increase in TPC, in shell samples. In core the activity of bromelain increased 350%. These results pinpoint the potential to increase the value of pineapple by-products by enhancing the amounts of bioactive compounds through MHP applicationinfo:eu-repo/semantics/publishedVersio

    Optoelectronics and Bio Devices on Paper Powered by Solar Cells

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    The employment of printing techniques as cost-effective methods to fabricate low cost, flexible, disposable and sustainable solar cells is intimately dependent on the substrate properties and the adequate electronic devices to be powered by them. Among such devices, there is currently a growing interest in the development of user-oriented and multipurpose systems for intelligent packaging or on-site medical diagnostics, which would greatly benefit from printable solar cells as their energy source for autonomous operation

    Zinc Biofortification in Vitis vinifera: Implications for Quality and Wine Production

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    Nowadays, there is a growing concern about micronutrient deficits in food products, with agronomic biofortification being considered a mitigation strategy. In this context, as Zn is essential for growth and maintenance of human health, a workflow for the biofortification of grapes from the Vitis vinifera variety Fernão Pires, which contains this nutrient, was carried out considering the soil properties of the vineyard. Additionally, Zn accumulation in the tissues of the grapes and the implications for some quality parameters and on winemaking were assessed. Vines were sprayed three times with ZnO and ZnSO4 at concentrations of 150, 450, and 900 g ha1 during the production cycle. Physiological data were obtained through chlorophyll a fluorescence data, to access the potential symptoms of toxicity. At harvest, treated grapes revealed significant increases of Zn concentration relative to the control, being more pronounced for ZnO and ZnSO4 in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO4-450 g ha1). The contents of the sugars and fatty acids, as well as the colorimetric analyses, were also assessed, but significant variations were not found among treatments. In general, Zn biofortification increased with ZnO and ZnSO4, without significantly affecting the physicochemical characteristics of grapesinfo:eu-repo/semantics/publishedVersio

    A genetically modified Plasmodium berghei parasite as a surrogate for whole-sporozoite vaccination against P. vivax malaria

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    © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Two malaria parasite species, Plasmodium falciparum (Pf) and P. vivax (Pv) are responsible for most of the disease burden caused by malaria. Vaccine development against this disease has focused mainly on Pf. Whole-sporozoite (WSp) vaccination, targeting pre-erythrocytic (PE) parasite stages, is a promising strategy for immunization against malaria and several PfWSp-based vaccine candidates are currently undergoing clinical evaluation. In contrast, no WSp candidates have been developed for Pv, mainly due to constraints in the production of Pv sporozoites in the laboratory. Recently, we developed a novel approach for WSp vaccination against Pf based on the use of transgenic rodent P. berghei (Pb) sporozoites expressing immunogens of this human-infective parasite. We showed that this platform can be used to deliver PE Pf antigens, eliciting both targeted humoral responses and cross-species cellular immune responses against Pf. Here we explored this WSp platform for the delivery of Pv antigens. As the Pv circumsporozoite protein (CSP) is a leading vaccine candidate antigen, we generated a transgenic Pb parasite, PbviVac, that, in addition to its endogenous PbCSP, expresses PvCSP under the control of a strictly PE promoter. Immunofluorescence microscopy analyses confirmed that both the PbCSP and the PvCSP antigens are expressed in PbviVac sporozoites and liver stages and that PbviVac sporozoite infectivity of hepatic cells is similar to that of its wild-type Pb counterpart. Immunization of mice with PbviVac sporozoites elicits the production of anti-PvCSP antibodies that efficiently recognize and bind to Pv sporozoites. Our results warrant further development and evaluation of PbviVac as a surrogate for WSp vaccination against Pv malaria.A.D. and J.C.S. were supported by the National Institute of Allergy and Infectious Diseases, National Institutes of Health (U19AI110820 and R01AI141900). A.M.M. acknowledges Fundação para a Ciência e Tecnologia, Portugal (FCT) for Grant PTDC-BBB-BMD-2695-2014. M.P. acknowledges the “la Caixa” Foundation for Grant HR21-848, the GSK OpenLab Foundation for grant TC269, and FCT for grant PTDC-SAU-INF-29550-2017. D.M. acknowledges FCT for grant SFRH/BD/144817/2019.info:eu-repo/semantics/publishedVersio

    Relationship between professional motivations and the expectation of staying at the same workplace: a cross-sectional descriptive study with physicians in Portugal

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    There is a global trend related to the migration of health professionals, particularly physicians, to the most densely populated areas. In Portugal, the unequal distribution of medical professionals is justified by the fact that in the most favoured areas, there are more career opportunities, better infrastructures and equipment, better working conditions and supervision, more and better social facilities and better salary. The aim of this work was to identify professional reasons associated with the expectation of staying at the same workplace. It was selected a simple random sample of 594 physicians out of a total of 18,711 registered physicians in Northern Regional Section of the Order of Physicians (NRSOP), Portugal Most physicians would like to stay at the same workplace due to: the prospect of training and working at the current location, the organizational level of the unit, the level of differentiation of the hospital/health centre, the availability to use the state-of-the-art medical and surgical technology, better rewards, the level of work differentiation in the unit/service, the possibility of reconciling public and private practice, good references of the current unit/working group, avoid unit/workgroup with bad references and the prospect of career progression. This study revealed that, for physicians, professional motivations/purposes have an influence on the expectations of staying or not at the same workplace. Therefore, the study recommends that policy makers should prioritize professional reasons when formulating and implementing measures to promote the fixing of medical professionals in order to achieve greater equity in access to health care.This work is supported by: the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 006971 (UID/SOC/04011)]; and national funds, through the FCT – Portuguese Foundation for Science and Technology under the project UID/SOC/04011/2013.info:eu-repo/semantics/publishedVersio

    Detection of silver nanoparticles inside marine diatom Thalassiosira pseudonana by electron microscopy and focused ion beam

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    In the following article an electron/ion microscopy study will be presented which investigates the uptake of silver nanoparticles (AgNPs) by the marine diatom Thalassiosira pseudonana, a primary producer aquatic species. This organism has a characteristic silica exoskeleton that may represent a barrier for the uptake of some chemical pollutants, including nanoparticles (NPs), but that presents a technical challenge when attempting to use electron-microscopy (EM) methods to study NP uptake. Here we present a convenient method to detect the NPs interacting with the diatom cell. It is based on a fixation procedure involving critical point drying which, without prior slicing of the cell, allows its inspection using transmission electron microscopy. Employing a combination of electron and ion microscopy techniques to selectively cut the cell where the NPs were detected, we are able to demonstrate and visualize for the first time the presence of AgNPs inside the cell membrane

    Persistent organic pollutant levels in human visceral and subcutaneous adipose tissue in obese individuals - Depot differences and dysmetabolism implications

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    Background: The role of persistent organic pollutants (POPs) with endocrine disrupting activity in the aetiology of obesity and other metabolic dysfunctions has been recently highlighted. Adipose tissue (AT) is a common site of POPs accumulation where they can induce adverse effects on human health. Objectives: To evaluate the presence of POPs in human visceral (vAT) and subcutaneous (scAT) adipose tissue in a sample of Portuguese obese patients that underwent bariatric surgery, and assess their putative association with metabolic disruption preoperatively, as well as with subsequent body mass index (BMI) reduction. Methods: AT samples (n=189) from obese patients (BMI ≥35) were collected and the levels of 13 POPs were determined by gas chromatography with electron-capture detection (GC-ECD). Anthropometric and biochemical data were collected at the time of surgery. BMI variation was evaluated after 12 months and adipocyte size was measured in AT samples. Results: Our data confirm that POPs are pervasive in this obese population (96.3% of detection on both tissues), their abundance increasing with age (RS=0.310, p<0.01) and duration of obesity (RS=0.170, p<0.05). We observed a difference in AT depot POPs storage capability, with higher levels of ΣPOPs in vAT (213.9±204.2 compared to 155.1±147.4 ng/g of fat, p<0.001), extremely relevant when evaluating their metabolic impact. Furthermore, there was a positive correlation between POP levels and the presence of metabolic syndrome components, namely dysglycaemia and hypertension, and more importantly with cardiovascular risk (RS=0.277, p<0.01), with relevance for vAT (RS=0.315, p<0.01). Finally, we observed an interesting relation of higher POP levels with lower weight loss in older patients. Conclusion: Our sample of obese subjects allowed us to highlight the importance of POPs stored in AT on the development of metabolic dysfunction in a context of obesity, shifting the focus to their metabolic effects and not only for their recognition as environmental obesogens

    Atherosclerosis and Bone Loss in Humans–Results From Deceased Donors and From Patients Submitted to Carotid Endarterectomy

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    Funding: We wish to thank all the collaborators (administrative staff, nurses, etc.) of the surgery block, as well as the doctors of the vascular surgery and transplantation departments of the Hospital of Santa Maria for the availability and assistance in the collection of the samples. We also thank Sociedade Portuguesa de Reumatologia for funding with two fellowships: Fundo de Apoio à Investigação 2014 and SPR/MSD 2015. DC-F received funding from a PhD grant from Fundação para a Ciência e a Tecnologia (SFRH/BD/80940/2011).Background and Aims: Atherosclerosis and osteoporosis share common risk factors, as well as inflammatory mechanisms. Our aim was to understand how atherosclerotic lesions are related with disturbances in bone. Methods: Gene expression of pro-inflammatory and bone metabolism related proteins (IL-1β, IL-6, IL-17A, TNF, RANKL, OPG, COL1, CTSK, OCL, TRAP, CBFA1, DKK1, SOST, ADIPOQ, and ADIPOR1) were analyzed in arteries and bones from 45 deceased donors and adipose tissue was used as control. Additionally, in 139 patients with advanced atherosclerosis submitted to carotid endarterectomy we compared calcium content (Alizarin red) and plaque inflammatory scores (CD3+, CD68+, and adiponectin) of patients with normal bone mineral density (BMD) with those with low BMD and explored the associations between gene expression in atherosclerotic plaques and BMD. Serum levels of pro-inflammatory and bone related proteins were measured both in donors and patients. Associations were investigated by the Pearson or Spearman correlation tests, and multivariate regression analyzes were performed when justified. Results: Gene expression of bone remodeling and pro-inflammatory proteins correlated positively in bone and aorta, independently of age and sex of donors, but not in adipose tissue. The expression of bone formation genes was significantly higher in atheroma plaques from endarterectomized patients with normal vs. low BMD as well as inflammatory CD68+ scores, regardless of patients' age and sex, but not of body mass index. No relationship was observed between serum levels and gene expression levels of pro-inflammatory or bone remodeling proteins. Conclusions: Our results suggest that the relationship between bones and vessels in the context of atherosclerotic disease and osteoporosis may rely on the intrinsic connection between the tissues involved, independently of disease stage. Serum measurements of pro-inflammatory and bone-remodeling proteins do not accurately translate tissue pathologic processes.publishersversionpublishe

    Implications on Mineral Elements, Sugars and Fatty Acids Accumulation in Tissues

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    Funding Information: This work received funding from PDR2020-101-030734 and Fundação para a Ciência e a Tecnologia, I.P. (FCT), Portugal, through the research units UIDB/04035/2020 (GeoBioTec), UIDB/00239/2020 (CEF) and UID/FIS/04559/2020 (LIBPhys) from the FCT/MCTES/PIDDAC. This work was further supported by the grant of Fundação para a Ciência e Tecnologia (FCT) UI/BD/150718/2020. Publisher Copyright: © 2022 by the authors.Following an agronomic approach for the Ca enrichment of Rocha pears, this study aimed to assess the interactions between mineral nutrients in fruit tissues at harvest and after storage for 5 months and to characterize the implications on the profile of sugars and fatty acids (FA). A total of seven foliar sprays (with concentrations of 0.1–0.6 kg·ha−1 Ca(NO3)2 and 0.8–8 kg·ha−1 CaCl2) were applied to pear trees. After harvest, the fruits were stored for 5 months, in environmentally controlled chambers, and the mineral contents in five regions (on the equatorial section) of the fruits were assessed, while the sugar and FA content were quantified. For both dates, all foliar sprayed treatments, at different extends, increased Ca content in the center and near the epidermis of Rocha pear fruits and the levels of K, Mn, Fe, Zn and Cu also varied. At harvest, the Ca treatments did not affect the levels of sucrose, glucose, fructose and sorbitol and, after storage, their concentrations remained higher in Ca-treated fruits. Additionally, the tendency of the relative proportions of FA was C18:2 > C18:1 > C16:0 > C18:3 > C18:0 > chains inferior to 16 C ( C16:0 > C18:3 > C18:0 > C18:1 > chains inferior to 16 C (<16:0). It is concluded that the heterogeneous distribution of Ca in the tissues of Rocha pear fruits results from its absorption in the peel after Ca(NO3)2 and CaCl2 sprays and from the xylemic flux in the core prior to maturity. Additionally, the hydrolysis of complex polysaccharides affects the contents of simpler sugars during maturation, ripening and senescence, while storage decreases the amount of total fatty acids (TFA), but the double bond index (DBI) indicate that cell membrane fluidity remains unaffected.publishersversionpublishe
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