19 research outputs found

    Experience of a predictive adaptive controller on pilot and industrial plants with transport phenomena

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    The existing experience on using MUSMAR, a predictive adaptive controller, on industrial and large scale pilot plants with transport phenomena is discussed. The processes to control have been selected because their dynamics depends not only on time, but also on space, being therefore described by partial differential equations, and implying increase difficulties for the controller. Case studies on an industrial boiler, an arc-welding machine, a distributed collector solar field and a water distribution canal are used to illustrate the main difficulties and the corresponding solutions when using MUSMAR. These include plant model uncertainty and start-up adaptation transients, large and uncertain plant i/o transport delay, existence of un-modelled dynamics, closed-loop response shaping and constraints. The emphasis of the presentation is on the practical impact of the theoretical properties of the MUSMAR algorithm and on their illustration by means of actual experiments on the real processes mentioned above

    The Action of Polyphenols in Diabetes Mellitus and Alzheimer's Disease: A Common Agent for Overlapping Pathologies

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    Diabetes Mellitus (DM) and Alzheimer's disease (AD) are two prevalent diseases in modern societies, which are caused mainly by current lifestyle, aging and genetic alterations. It has already been demonstrated that these two diseases are associated, since individuals suffering from DM are prone to develop AD. Conversely, it is also known that individuals with AD are more susceptible to DM, namely type 2 diabetes (T2DM). Therefore, these two pathologies, although completely different in terms of symptomatology, end up sharing several mechanisms at the molecular level, with the most obvious being the increase of oxidative stress and inflammation. Polyphenols are natural compounds widely spread in fruits and vegetables whose dietary intake has been considered inversely proportional to the incidence of DM and AD. So, it is believed that this group of phytochemicals may have preventive and therapeutic potential, not only by reducing the risk and delaying the development of these pathologies, but also by improving brain's metabolic profile and cognitive function. The aim of this review is to understand the extent to which DM and AD are related pathologies, the degree of similarity and the relationship between them, to detail the molecular mechanisms by which polyphenols may exert a protective effect, such as antioxidant and anti-inflammatory effects, and highlight possible advantages of their use as common preventive and therapeutic alternatives.info:eu-repo/semantics/publishedVersio

    Comparative genomics suggests primary homothallism of Pneumocystis species

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    This work was supported by the Swiss National Science Foundation grant 310030-146135 to P.M.H. and M.P. O.H.C. is supported by the Swiss National Science Foundation fellowship grant 151780.Pneumocystis species are fungal parasites of mammal lungs showing host specificity. Pneumocystis jirovecii colonizes humans and causes severe pneumonia in immunosuppressed individuals. In the absence of in vitro cultures, the life cycle of these fungi remains poorly known. Sexual reproduction probably occurs, but the system of this process and the mating type (MAT) genes involved are not characterized. In the present study, we used comparative genomics to investigate the issue in P. jirovecii and Pneumocystis carinii, the species infecting rats, as well as in their relative Taphrina deformans. We searched sex-related genes using 103 sequences from the relative Schizosaccharomyces pombe as queries. Genes homologous to several sex-related role categories were identified in all species investigated, further supporting sexuality in these organisms. Extensive in silico searches identified only three putative MAT genes in each species investigated (matMc, matMi, and matPi). In P. jirovecii, these genes clustered on the same contig, proving their contiguity in the genome. This organization seems compatible neither with heterothallism, because two different MAT loci on separate DNA molecules would have been detected, nor with secondary homothallism, because the latter involves generally more MAT genes. Consistently, we did not detect cis-acting sequences for mating type switching in secondary homothallism, and PCR revealed identical MAT genes in P. jirovecii isolates from six patients. A strong synteny of the genomic region surrounding the putative MAT genes exists between the two Pneumocystis species. Our results suggest the hypothesis that primary homothallism is the system of reproduction of Pneumocystis species and T. deformans. IMPORTANCE: Sexual reproduction among fungi can involve a single partner (homothallism) or two compatible partners (heterothallism). We investigated the issue in three pathogenic fungal relatives: Pneumocystis jirovecii, which causes severe pneumonia in immunocompromised humans; Pneumocystis carinii, which infects rats; and the plant pathogen Taphrina deformans. The nature, the number, and the organization within the genome of the genes involved in sexual reproduction were determined. The three species appeared to harbor a single genomic region gathering only three genes involved in sexual differentiation, an organization which is compatible with sexual reproduction involving a single partner. These findings illuminate the strategy adopted by fungal pathogens to infect their hosts.publishersversionpublishe

    Adaptações no Serviço de Cirurgia Vascular do CHULN durante a pandemia de COVID-19 e impacto na atividade global

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    © SPACVWith the onset of the SARS-CoV-2 pandemic in early 2020, health services and personnel adapted their resources to mitigate and control the outbreak. These needs inevitably led to adaptations in most medical and surgical departments, including in our Vascular Surgery department. As we are facing a second outbreak of this pandemic, with unpredictable outcomes and repercussions in health services, it is crucial to learn from previous experiences and share strategies to perform the best care to our patients, despite the restrictions that have been imposed. Through this paper, we review the adaptations in Centro Hospitalar Universitário Lisboa Norte and particularly in our department to overcome the pandemic. We also assess the impact of these changes in our activity and compare with the experience of other fellow surgeons. With an upcoming second outbreak, it is crucial to learn from this and other departments’ experiences to overcome a potential health crisis.info:eu-repo/semantics/publishedVersio

    Vitamin D-related polymorphisms and vitamin D levels as risk biomarkers of COVID-19 disease severity

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    © The Author(s) 2021. 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 licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence 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 licence, visit http://creativecommons.org/licenses/by/4.0/.Vitamin D is a fundamental regulator of host defences by activating genes related to innate and adaptive immunity. Previous research shows a correlation between the levels of vitamin D in patients infected with SARS-CoV-2 and the degree of disease severity. This work investigates the impact of the genetic background related to vitamin D pathways on COVID-19 severity. For the first time, the Portuguese population was characterized regarding the prevalence of high impact variants in genes associated with the vitamin D pathways. This study enrolled 517 patients admitted to two tertiary Portuguese hospitals. The serum concentration of 25 (OH)D, was measured in the hospital at the time of patient admission. Genetic variants, 18 variants, in the genes AMDHD1, CYP2R1, CYP24A1, DHCR7, GC, SEC23A, and VDR were analysed. The results show that polymorphisms in the vitamin D binding protein encoded by the GC gene are related to the infection severity (p = 0.005). There is an association between vitamin D polygenic risk score and the serum concentration of 25 (OH)D (p = 0.04). There is an association between 25 (OH)D levels and the survival and fatal outcomes (p = 1.5e-4). The Portuguese population has a higher prevalence of the DHCR7 RS12785878 variant when compared with its prevalence in the European population (19% versus 10%). This study shows a genetic susceptibility for vitamin D deficiency that might explain higher severity degrees in COVID-19 patients. These results reinforce the relevance of personalized strategies in the context of viral diseases.This project was supported by the “Fundação para a Ciência e Tecnologia”, program “Research 4 Covid-19 Apoio especial a projetos de implementação rápida para soluções inovadoras de resposta à pandemia de COVID-19”. It was also partially supported by each institution.info:eu-repo/semantics/publishedVersio

    Variable Sampling Adaptive control of a Distributed Collector Solar Field

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    Distributed collector solar fields are spatially distributed engineering systems, which aim at collecting and storing energy from solar radiation. They are formed by mirrors which concentrate direct incident sun light in a pipe where a fluid, able to accumulate thermic energy, flows. From the control point of view, the objective considered here consists of making the outlet oil temperature to track a reference signal by manipulating the oil flow, in the possible presence of fast disturbances caused by passing clouds. Although this plant may be successfully controlled by methods assuming it to be modeled as a "black box" lumped parameter system, the point of view advocated in this paper is that explicit consideration of its distributed character leads to an increased control performance. In this respect, the contributions of this paper are twofold: First, a controller relying on variable sampling is developed. This is derived from the partial differential equation describing the oil temperature evolution in time and space on the field and has the effect of linearizing the plant model. Second, the resulting performance is illustrated by means of experiments performed in an actual solar field. The experiments reported show that it is possible to make fast temperature setpoint changes, with reduced overshoot. The ideas presented are applicable to other types of industrial processes, involving transport phenomena

    A catastrophic seronegative anti-phospholipid syndrome: case and literature review

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    © The Author(s). 2021. 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 licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence 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 licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Background: Antiphospholipid Syndrome (APS) is a multisystemic autoimmune disease characterized by arterial and venous thrombosis and / or obstetric morbidity in the presence of at least one circulating anti-phospholipid antibody. The spectrum of vascular events varies from deep venous thrombosis to catastrophic APS, a rare form characterized by acute multiorgan thrombosis and high mortality. Case report: We present the case of a 32-week pregnant woman arriving in the hospital emergency room with bilateral acute lower limb ischemia. In the obstetric evaluation, fetal death was declared. Computerized Tomography angiography showed pulmonary embolism of both pulmonary arteries, areas of splenic and right renal infarction and multiple arterial and venous thrombosis. The patient underwent urgent caesarean section and axillary-bifemoral bypass. No events registered. In the postoperative period, in an intensive care unit, treatment with rituximab and plasmapheresis were added to anticoagulant therapy. The laboratorial investigation was negative for thrombophilia and autoimmune diseases. Conclusion: Catastrophic APS develops quickly, with multiorgan involvement and high mortality rate. The presented case poses a multidisciplinary challenge, with the surgical approach of extra-anatomical revascularization being less invasive and guaranteeing immediate perfusion of the lower limbs. Although the serological tests were negative for anti-phospholipid antibodies, this case hardly fits into another diagnosis. Therefore, it was treated as a catastrophic APS, having shown a favorable evolution.info:eu-repo/semantics/publishedVersio

    Homarus gammarus (Crustacea: Decapoda) larvae under an ocean acidification scenario: responses across different levels of biological organization

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    The present study evaluated the effects of exposure to different target pCO2 levels: control (C: 370 μatm, pH =8.15) and ocean acidification (OA: 710 μatm, pH=7.85) on development and biochemical responses related with oxidative stress and energy metabolism during the crustacean Homarus gammarus (L.) larval development, integrating different levels of biological organization. After hatching in the laboratory, larvae from the same female brood were exposed to the described conditions from hatching until reaching Stage III (last larval stage - 11 days). H. gammarus larvae demonstrated some susceptibility when addressing the predicted pCO2 levels for 2100. Further analysis at the biochemical and physiological level highlighted the occurrence of oxidative stress in the OA scenario (Superoxide Dismutase reduction and higher DNA damage) that was followed by developmental effects, increased inter-moult period from SII to SIII and reduced growth. The extended exposure to these conditions may affect organisms' key life-cycle functions such as physiological resistance, growth, sexual maturation, or reproduction with implications in their future fitness and population dynamics.info:eu-repo/semantics/publishedVersio

    White Tea Intake Abrogates Markers of Streptozotocin-Induced Prediabetes Oxidative Stress in Rat Lungs’

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    Prediabetes (PrDM) is a prodromal stage of diabetes mellitus (DM) with an increasing prevalence worldwide. During DM progression, individuals gradually develop complications in various organs. However, lungs are suggested to be affected later than other organs, such as the eyes, heart or brain. In this work, we studied the effects of PrDM on male Wistar rats’ lungs and whether the regular consumption of white tea (WTEA) for 2 months contributes to the improvement of the antioxidant profile of this tissue, namely through improved activity of the first line defense antioxidant enzymes, the total antioxidant capacity and the damages caused in proteins, lipids and histone H2A. Our data shows that PrDM induced a decrease in lung superoxide dismutase and glutathione peroxidase activities and histone H2A levels and an increase in protein nitration and lipid peroxidation. Remarkably, the regular WTEA intake improved lung antioxidant enzymes activity and total antioxidant capacity and re-established the values of protein nitration, lipid peroxidation and histone H2A. Overall, this is the first time that lung is reported as a major target for PrDM. Moreover, it is also the first report showing that WTEA possesses relevant chemical properties against PrDM-induced lung dysfunction
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