409 research outputs found

    Estimates of nonequilibrium ionization phenomena in the inviscid Apollo plasma sheath

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    Nonequilibrium ionization in asymmetric plasma sheath determined for Apollo spacecraft at superorbital velocity reentr

    Nachtlärminduzierte Schlafstörungen und Herz-Kreislauf-Risiko

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    Impairment of sleep in the sense of insomnias, i.e. difficulties falling asleep and staying asleep, early morning awakening and chronical unrestful sleep is widespread in the population and are associated with a variety of physical and mental health disorders. The environmental causes of insomnia include a number of factors, with nighttime noise being an important cause. Recent data from the European Environment Agency shows that environmental noise (road traffic, railway, aircraft and industrial noise) causes severe sleep disorders among 6.5 million people in Europe. New epidemiological and mechanistic field studies show that in particular night traffic noise can lead, among other things, to impaired vascular function, thrombo-inflammatory changes, an increase in stress hormones and increased blood pressure, representing significant risk factors for cardiovascular diseases. According to the European Environment Agency, environmental noise causes 48000 additional cases of ischemic heart disease and 12000 premature deaths each year

    Lärm und Herz-Kreislauf-Erkrankungen

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    Environmental noise is a significant environmental risk factor for public health. The European Environment Agency states that at least 20% of the European population are exposed to harmful day-evening-night noise levels of 55 decibels (dB), whereas the World Health Organization recommends up to 10 dB lower limit values, depending on the noise source, for the protection of the population. Chronic noise can interfere with daily activities and sleep and trigger mental and physiological stress reactions that can increase the risk of cardiovascular disease in the long term. Therefore, preventive measures at the source including noise-reducing structural changes are essential to ensure compliance with noise limits and to protect the population from the negative health effects of noise

    Discovery of new therapeutic redox targets for cardioprotection against ischemia/reperfusion injury and heart failure

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    Global epidemiological studies reported a shift from maternal/infectious communicable diseases to chronic non-communicable diseases and a major part is attributable to atherosclerosis and metabolic disorders. Accordingly, ischemic heart disease was identified as a leading risk factor for global mortality and morbidity with a prevalence of 128 million people. Almost 9 million premature deaths can be attributed to ischemic heart disease and subsequent acute myocardial infarction and heart failure, also representing a substantial socioeconomic burden. As evidenced by typical oxidative stress markers such as lipid peroxidation products or oxidized DNA/RNA bases, the formation of reactive oxygen species by various sources (NADPH oxidases, xanthine oxidase and mitochondrial resperatory chain) plays a central role for the severity of ischemia/reperfusion damage. The underlying mechanisms comprise direct oxidative damage but also adverse redox-regulation of kinase and calcium signaling, inflammation and cardiac remodeling among others. These processes and the role of reactive oxygen species are discussed in the present review. We also present and discuss potential targets for redox-based therapies that are either already established in the clinics (e.g. guanylyl cyclase activators and stimulators) or at least successfully tested in preclinical models of myocardial infarction and heart failure (mitochondria-targeted antioxidants). However, reactive oxygen species have not only detrimental effects but are also involved in essential cellular signaling and may even act protective as seen by ischemic pre- and post-conditioning or eustress – which makes redox therapy quite challenging

    Effects of tobacco cigarettes, e-cigarettes, and waterpipe smoking on endothelial function and clinical outcomes

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    Tobacco smoking is a leading cause of non-communicable disease globally and is a major risk factor for cardiovascular disease (CVD) and lung disease. Importantly, recent data by the World Health Organizations (WHO) indicate that in the last two decades global tobacco use has significantly dropped, which was largely driven by decreased numbers of female smokers. Despite such advances, the use of e-cigarettes and waterpipes (shisha, hookah, narghile) is an emerging trend, especially among younger generations. There is growing body of evidence that e-cigarettes are not a harm-free alternative to tobacco cigarettes and there is considerable debate as to whether e-cigarettes are saving smokers or generating new addicts. Here, we provide an updated overview of the impact of tobacco/waterpipe (shisha) smoking and e-cigarette vaping on endothelial function, a biomarker for early, subclinical, atherosclerosis from human and animal studies. Also their emerging adverse effects on the proteome, transcriptome, epigenome, microbiome, and the circadian clock are summarized. We briefly discuss heat-not-burn tobacco products and their cardiovascular health effects. We discuss the impact of the toxic constituents of these products on endothelial function and subsequent CVD and we also provide an update on current recommendations, regulation and advertising with focus on the USA and Europe. As outlined by the WHO, tobacco cigarette, waterpipe, and e-cigarette smoking/vaping may contribute to an increased burden of symptoms due to coronavirus disease 2019 (COVID-19) and to severe health consequences

    Acute exposure to simulated nocturnal train noise leads to impaired sleep quality and endothelial dysfunction in young healthy men and women: a sex-specific analysis

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    A series of human field studies demonstrated that simulated nocturnal traffic noise exposure impaired sleep quality and endothelial function, which could be significantly improved after intake of vitamin C in case of endothelial function. However, it remains unclear whether these changes follow a sex-specific pattern. Thus, we aimed to analyze the effect of simulated nocturnal train noise exposure on sleep quality, endothelial function and its associated changes after vitamin C intake, and other hemodynamic and biochemical parameters in young healthy men and women. We used data from a randomized crossover study, wherein 70 healthy volunteers (50% women) were each exposed to one control pattern (regular background noise) and two different train noise scenarios (30 or 60 train noise events per night, with average sound pressure levels of 52 and 54 dB(A), respectively, and peak sound level of 73-75 dB(A)) in their homes for three nights. After each night, participants visited the study center for the measurement of endothelial function as well as other hemodynamic and biochemical parameters. Sleep quality measured via self-report was significantly impaired after noise 30 and noise 60 nights in both men and women (p < 0.001 vs. control). Likewise, endothelial function measured by flow-mediated dilation (FMD) was significantly impaired after noise 30 and noise 60 nights in both men and women (p < 0.001 vs. control). While in women, vitamin C intake significantly improved FMD after both noise 30 and noise 60 study nights compared to control nights, no significant changes were observed in men. Exposure to simulated nocturnal train noise impairs sleep quality and endothelial function in both men and women, whereas a significant improvement of endothelial function after noise exposure and vitamin C intake could only be observed in women. These findings suggest for the first time that in men other mechanisms such as oxidative stress causing endothelial dysfunction may come into play

    Gesundheitsrisiko Mobilfunkstrahlung? Was ändert sich mit 5G?

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    Exposure of the population to radiofrequency electromagnetic fields (RF-EMF) is dominated by the use of wireless communication devices close to the body. Exposure from transmitters far from the body is on average several orders of magnitude below the international guideline values. With increasing mobile data usage and the associated use of higher frequencies for 5G, a densification of the mobile network is to be expected. However, this will not necessarily increase the overall RF-EMF exposure of the population, as mobile phones emit less with better signal quality. 5G is a technological advancement of the previous mobile radio technology with the same biophysical properties. So far, no health effects below the guideline limits have been consistently demonstrated for RF-EMF. Biological effects such as changes of the electrical activity of the brain or the oxidative balance were observed for high local exposure in the range of the exposure guideline limits. According to current knowledge, they do not represent a health risk

    One-loop corrections to the instanton transition in the two-dimensional Abelian Higgs model

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    We present an evaluation of the fluctuation determinant which appears as a prefactor in the instanton transition rate for the two-dimensional Abelian Higgs model. The corrections are found to change the rate at most by a factor of 2 for 0.4 < M_W/M_H < 2.0.Comment: DO-TH-94/17, 20 pages, 4 figures appended as uucompressed .eps files, LaTeX, needs epsfig.st
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