8 research outputs found

    Design and Experimental Validation of an Explicit MPC Controller for Regulating Temperature in PEM Fuel Cell Systems

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    This paper proposes a temperature controller for PEM fuel cell systems with an air blower as thermal circuit. The objective of this controller is to maintain the stack temperature over a given set-point which is obtained from the results of a real-time optimization algorithm with the goal of minimizing the stack degradation and maximizing the global efficiency. An Explicit MPC is proposed to deal with this control problem which presents delays, the critical sampling time, constraints and disturbances. The simulation results show good performance of the controller which accurately tracks the temperature reference over the overall range of operating conditions. Furthermore, the controller is implemented in real-time on a PEM fuel cell test-bench which is installed in the Fuel Cell Laboratory at the University of Seville

    Herbal Infusions as a Part of the Mediterranean Diet and Their Association with Psychological Resilience: The Paradigm of Greek Mountain Tea

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    Herbal infusions (HI) are a popular type of beverage known for their potential health benefits due to the extraction of phytochemicals and bioactive compounds. The Mediterranean Diet (MD) is a well-known dietary pattern with beneficial effects on health, and Psychological Resilience (PsyR) is a key indicator of mental health and human well-being. The aim of this cross-sectional study was to explore the relationship between HI and the MD, as well as their association with PsyR. The study included 398 healthy adults from Greece who participated voluntarily in an online research survey. The results indicated that 45.9% of participants consumed HI more than twice per week. There was a statistically significant association between the weekly consumption of HI and the Mediterranean Diet Adherence Screener (14-MEDAS), which identified HI consumption as a prognostic factor of high adherence to the MD. Additionally, HI consumption was significantly associated with PsyR. St John’s wort, green tea, and Greek mountain tea were associated with higher levels of PsyR. Greek mountain tea was also associated with a healthful and sustainable lifestyle. These findings suggest that HI are an integral part of the Mediterranean Diet, and their consumption is associated with PsyR. Promoting the consumption of HI such as Greek mountain tea and other herbs could be an effective way to promote healthy lifestyle behaviors and sustainable practices. Further randomized control trials are needed to confirm the results of this study

    COVID-19 Infection and Response to Vaccination in Chronic Kidney Disease and Renal Transplantation: A Brief Presentation

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    Chronic kidney disease (CKD) is associated with phenotypic and functional changes in the immune system, followed by detrimental clinical consequences, such as severe infections and defective response to vaccination. Two years of the pandemic, due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have undoubtedly changed the world; however, all efforts to confront infection and provide new generation vaccines tremendously improved our understanding of the mechanisms of the immune response against infections and after vaccination. Humoral and cellular responses to vaccines, including mRNA vaccines, are apparently affected in CKD patients, as elimination of recent thymic emigrant and naïve lymphocytes and regulatory T-cells, together with contraction of T-cell repertoire and homeostatic proliferation rate, which characterized CKD patients are responsible for impaired immune activation. Successful renal transplantation will restore some of these changes, although several epigenetic changes are irreversible and even accelerated by the induction of immunosuppression. Response to vaccination is definitely impaired among both CKD and RT patients. In the present review, we analyzed the differences in immune response after vaccination between these patients and healthy individuals and depicted specific parameters, such as alterations in the immune system, predisposing to this deficient response

    Promising Novel Therapies in the Treatment of Aortic and Visceral Aneurysms

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    Aortic and visceral aneurysms affect large arterial vessels, including the thoracic and abdominal aorta, as well as visceral arterial branches, such as the splenic, hepatic, and mesenteric arteries, respectively. Although these clinical entities have not been equally researched, it seems that they might share certain common pathophysiological changes and molecular mechanisms. The yet limited published data, with regard to newly designed, novel therapies, could serve as a nidus for the evaluation and potential implementation of such treatments in large artery aneurysms. In both animal models and clinical trials, various novel treatments have been employed in an attempt to not only reduce the complications of the already implemented modalities, through manufacturing of more durable materials, but also to regenerate or replace affected tissues themselves. Cellular populations like stem and differentiated vascular cell types, large diameter tissue-engineered vascular grafts (TEVGs), and various molecules and biological factors that might target aspects of the pathophysiological process, including cell-adhesion stabilizers, metalloproteinase inhibitors, and miRNAs, could potentially contribute significantly to the treatment of these types of aneurysms. In this narrative review, we sought to collect and present relevant evidence in the literature, in an effort to unveil promising biological therapies, possibly applicable to the treatment of aortic aneurysms, both thoracic and abdominal, as well as visceral aneurysms

    Natural Functional Foods as a Part of the Mediterranean Lifestyle and Their Association with Psychological Resilience and Other Health-Related Parameters

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    Natural Functional Foods (NFFs) are unprocessed foods with proven health benefits beyond their nutritional value. The Mediterranean Diet (MD) and Mediterranean Lifestyle (MEDILIFE) are well known for their beneficial effects on health. Psychological Resilience (PsyR) is not only an important factor in human well-being; it is also regarded as a key indicator of mental health. The purpose of this study was to explore the relationship between NFFs and the MD and MEDILIFE in Greece, as well as their association with PsyR and other health-related parameters. In a cross-sectional design, 338 healthy adults participated voluntarily in an online research survey. There was a statistically significant association between the consumption of NFFs grown and produced in the Mediterranean region and the MD and MEDILIFE (p p p p p p < 0.01 compared with no weight loss). This study identified NFFs as a part of the MD and MEDILIFE. NFFs linked to the MEDILIFE could help predict the outcome of a weight loss diet and appear to have a positive effect on PsyR, sleep quality, and maintaining a healthy weight. Thus, the consumption of NFFs grown and produced in the Mediterranean region could be a natural, healthy, and sustainable way of enhancing physical–mental health. Randomised controlled trials should be conducted to confirm the findings of this cross-sectional study

    Serum OPG and RANKL Levels as Risk Factors for the Development of Cardiovascular Calcifications in End-Stage Renal Disease Patients in Hemodialysis

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    Cardiovascular calcifications (CVC) are frequently observed in chronic kidney disease (CKD) patients and contribute to their cardiovascular mortality. The aim of the present study was to investigate the impact of osteoprotegerin (OPG)/Receptor Activator of NF-κΒ (RANK)/RANK ligand (RANKL) pathway in the development and evolution of CVCs in hemodialysis patients. In total, 80 hemodialysis patients were assessed for the presence of vascular (abdominal aorta and muscular arteries) calcifications and results were correlated to serum OPG and RANKL levels and the OPG/RANKL ratio. Traditional cardiovascular risk factors and mineral bone disease parameters were also estimated. The presence of VCs was also evaluated 5 years after the initiation of the study, and results were correlated to the initial serum OPG levels. Age, diabetes mellitus, coronary artery disease and OPG levels (p p = 0.026), but they were not correlated with the progression of VCs. Serum OPG levels are positively and independently associated with VCs in HD patients, but not with their progression. RANKL levels did not show any associations, whereas further studies are needed to establish the significance of OPG/RANKL ratio
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