49 research outputs found

    Endocrine hormone imbalance in heart failure with reduced ejection fraction: A cross-sectional study

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    BACKGROUND AND AIMS Sustained neurohormonal activation plays a central role in the progression of heart failure (HF). Other endocrine axes may also be affected. It was the aim of this study to examine the endocrine profile (thyroid, parathyroid, glucocorticoid, and sex hormones) in a contemporary sample of patients with HF and reduced ejection fraction (EF) on established disease-modifying therapy. METHODS This study prospectively measured morning fasting hormones in 52 ambulatory and stable HF patients with EF < 50% on disease-modifying therapy (mean age 63 ± 11 years, 29% female, mean LVEF 32 ± 9.6%) and compared them to 54 patients at elevated risk for HF (61 ± 12 years, 28% female) and 62 healthy controls (HC; 61 ± 13 years, 27% female). Main comparisons were performed using one-way analysis of variance. Associations with biomarkers were studied with linear regression. RESULTS HF patients showed a reduced free triiodothyronine (fT3)/free thyroxine (fT4) ratio compared to HC (0.30 ± 0.06 vs. 0.33 ± 0.05, p = 0.046). Parathyroid hormone (PTH) and cortisol were increased in HF compared to both HC (median [IQR] 59 [50-84] vs. 46 [37-52] ng/L, p < 0.001 and 497 ± 150 vs. 436 ± 108 nmol/L, p = 0.03, respectively) and patients at risk (both p < 0.001). Total testosterone was reduced in male HF compared to HC (14.4 ± 6.6 vs. 18.6 ± 5.3 nmol/L; p = 0.01). No differences in TSH, estradiol, progesterone, and prolactin were found. Lower fT3 levels were found in HF with EF < 40% versus EF 40%-49% (4.6 ± 0.3 vs. 5.2 ± 0.7 pmol/L, p = 0.009). In HF patients, fT3 was an independent predictor of NT-proBNP and high-sensitivity troponin T in multiple regression analysis. PTH was positively associated with NT-proBNP. CONCLUSION There is evidence of endocrine hormonal imbalance in HF with reduced EF beyond principal neurohormones and despite the use of disease-modifying therapy

    Challenges and prospects of automated disassembly of fuel cells for a circular economy

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    The hydrogen economy is driven by the growing share of renewable energy and electrification of the transportation sector. The essential components of a hydrogen economy are fuel cells and electrolysis systems. The scarcity of the resources to build these components and the negative environmental impact of their mining requires a circular economy. Concerning disassembly, economical, ergonomic, and safety reasons make a higher degree of automation necessary. Our work outlines the challenges and prospects on automated disassembly of fuel cell stacks. This is carried out by summarizing the state-of-the-art approaches in disassembly and conducting manual non-/destructive disassembly experiments of end-of-life fuel cell stacks. Based on that, a chemical and mechanical analysis of the fuel cell components is performed. From this, an automation potential for the disassembly processes is derived and possible disassembly process routes are modeled. Moreover, recommendations are given regarding disassembly system requirements using a morphological box

    Viscosity and Diffusion: Crowding and Salt Effects in Protein Solutions

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    We report on a joint experimental-theoretical study of collective diffusion in, and static shear viscosity of solutions of bovine serum albumin (BSA) proteins, focusing on the dependence on protein and salt concentration. Data obtained from dynamic light scattering and rheometric measurements are compared to theoretical calculations based on an analytically treatable spheroid model of BSA with isotropic screened Coulomb plus hard-sphere interactions. The only input to the dynamics calculations is the static structure factor obtained from a consistent theoretical fit to a concentration series of small-angle X-ray scattering (SAXS) data. This fit is based on an integral equation scheme that combines high accuracy with low computational cost. All experimentally probed dynamic and static properties are reproduced theoretically with an at least semi-quantitative accuracy. For lower protein concentration and low salinity, both theory and experiment show a maximum in the reduced viscosity, caused by the electrostatic repulsion of proteins. The validity range of a generalized Stokes-Einstein (GSE) relation connecting viscosity, collective diffusion coefficient, and osmotic compressibility, proposed by Kholodenko and Douglas [PRE 51, 1081 (1995)] is examined. Significant violation of the GSE relation is found, both in experimental data and in theoretical models, in semi-dilute systems at physiological salinity, and under low-salt conditions for arbitrary protein concentrations

    RAMPup - flexible Montagemodule

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    Das vorgestellte Projekt RAMPup zielt darauf ab, die Wettbewerbsfähigkeit produzierender KMU zu verbessern, indem der für die Automatisierung kleiner Produktionslinien erforderliche Integrationsaufwand effektiv verringert wird. Roboter-Automatisierungsmodule kapseln dazu verschiedenste Roboterprozesse in jeweils einer einzigen, in sich geschlossenen Einheit, die sowohl Hardware als auch Steuerungssoftware umfasst. Es werden Module zum Schrauben, Dosieren, Nieten, Pressen, Gravieren sowie zur kraftgeregelten Montage von Bauteilen vorgestellt. Durch die modulare Bauweise kann sehr schnell zwischen diesen Prozessen gewechselt werden

    Endothelial dysfunction in COVID-19: Current findings and therapeutic implications

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    Coronavirus disease 2019 (COVID-19) increases the risk of several non-pulmonary complications such as acute myocardial injury, renal failure or thromboembolic events. A possible unifying explanation for these phenomena may be the presence of profound endothelial dysfunction and injury. This review provides an overview on the association of endothelial dysfunction with COVID-19 and its therapeutic implications. Endothelial dysfunction is a common feature of the key comorbidities that increase risk for severe COVID-19 such as hypertension, obesity, diabetes mellitus, coronary artery disease or heart failure. Preliminary studies indicate that vascular endothelial cells can be infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and evidence of widespread endothelial injury and inflammation is found in advanced cases of COVID-19. Prior evidence has established the crucial role of endothelial cells in maintaining and regulating vascular homeostasis and blood coagulation. Aggravation of endothelial dysfunction in COVID-19 may therefore impair organ perfusion and cause a procoagulatory state resulting in both macro- and microvascular thrombotic events. Angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and statins are known to improve endothelial dysfunction. Data from smaller observational studies and other viral infections suggests a possible beneficial effect in COVID-19. Other treatments that are currently under investigation for COVID-19 may also act by improving endothelial dysfunction in patients. Focusing therapies on preventing and improving endothelial dysfunction could improve outcomes in COVID-19. Several clinical trials are currently underway to explore this concept

    Endothelial dysfunction in cardiovascular disease and Flammer syndrome-similarities and differences

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    The endothelium has increasingly been recognized as a smart barrier and a key regulator of blood flow in micro- and macrovascular beds. Endothelial dysfunction marks a stage of atherosclerosis and is an important prognostic marker for cardiovascular disease. Yet, some people who tend to be slim and physically active and with rather low blood pressure show a propensity to respond to certain stimuli such as emotional stress with endothelial-mediated vascular dysregulation (Flammer syndrome). This leads to characteristic vascular symptoms such as cold hands but also a risk for vascular-mediated diseases such as normal-tension glaucoma. It is the aim of this review to delineate the differences between Flammer syndrome and its "counterpart" endothelial dysfunction in the context of cardiovascular diseases

    Cocoa, blood pressure, and vascular function

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    Cardiovascular disease (CVD) represents the most common cause of death worldwide. The consumption of natural polyphenol-rich foods, and cocoa in particular, has been related to a reduced risk of CVD, including coronary heart disease and stroke. Intervention studies strongly suggest that cocoa exerts a beneficial impact on cardiovascular health, through the reduction of blood pressure (BP), improvement of vascular function, modulation of lipid and glucose metabolism, and reduction of platelet aggregation. These potentially beneficial effects have been shown in healthy subjects as well as in patients with risk factors (arterial hypertension, diabetes, and smoking) or established CVD (coronary heart disease or heart failure). Several potential mechanisms are supposed to be responsible for the positive effect of cocoa; among them activation of nitric oxide (NO) synthase, increased bioavailability of NO as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on BP and vascular function

    Die aktuellen europäischen und amerikanischen Hypertonie-Leitlinien

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    At the end of 2013, the long-awaited guidelines of the Eighth Joint National Committee (JNC8) were published. These guidelines developed nine specific recommendations for the management of arterial hypertension. The harmonization of blood pressure treatment thresholds and goals represents a convenient simplification for the practicing physician. However, the recommendations did not come without controversy. Especially the raise of the treatment goal in patients aged 60 years or older was criticized. In this and other aspects, the 2013 guidelines of the European Society of Cardiology and European Society of Hypertension (ESC/ESH 2013) share a different point of view. The article tries to summarize the different viewpoints and to provide an overview over the increasing number of hypertension guidelines. Ende 2013 erschien die lang erwartete Leitlinie des achten US-amerikanischen Joint National Committee (JNC8). In dieser wurden neun konkrete Empfehlungen zur Behandlung der arteriellen Hypertonie erarbeitet. Insbesondere die Harmonisierung der Grenz- und Zielblutdruckwerte stellt eine Vereinfachung für den praktizierenden Mediziner dar. Die Empfehlungen blieben jedoch nicht ohne Kontroverse. Besonders die Erhöhung des Zielblutdrucks auf Werte von unter 150/90 mmHg bei Patienten gleich oder älter 60 Jahre wurde kritisiert. In diesem Punkt und auch der Frage der geeigneten Antihypertensiva zeigen sich Unterschiede zur aktuellen Leitlinie der European Society of Cardiology und European Society of Hypertension (ESC/ESH 2013). Dieser Artikel versucht die verschiedenen Standpunkte darzulegen und so einen Überblick über den wachsenden Bereich der Hypertonie-Leitlinien zu liefern
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