114 research outputs found

    Effect of local pressure transients on the deformations and stresses in cylindrical ducts. Volume I - Theory and design charts

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    Axially symmetric dynamic response solutions for cylinders subjected to pressure transients arising in propulsion system

    Effect of local pressure transients on the deformations and stresses in cylindrical ducts. Volume II - User's manual for general purpose program

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    Users manual for general purpose digital computer program for predicting dynamic response of cylinders subjected to ramp and sinusoidal pressure transient

    Use of gene expression profiling to identify candidate genes for pretherapeutic patient classification in acute appendicitis

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    Background: Phlegmonous and gangrenous appendicitis represent independent pathophysiological entities with different clinical courses ranging from spontaneous resolution to septic disease. However, reliable predictive methods for these clinical phenotypes have not yet been established. In an attempt to provide pathophysiological insights into the matter, a genomewide gene expression analysis was undertaken in patients with acute appendicitis. Methods: Peripheral blood mononuclear cells were isolated and, after histological confirmation of PA or GA, analysed for genomewide gene expression profiling using RNA microarray technology and subsequent pathway analysis. Results: Samples from 29 patients aged 7–17 years were included. Genomewide gene expression analysis was performed on 13 samples of phlegmonous and 16 of gangrenous appendicitis. From a total of 56 666 genes, 3594 were significantly differently expressed. Distinct interaction between T and B cells in the phlegmonous appendicitis group was suggested by overexpression of T cell receptor α and β subunits, CD2, CD3, MHC II, CD40L, and the B cell markers CD72 and CD79, indicating an antiviral mechanism. In the gangrenous appendicitis group, expression of genes delineating antibacterial mechanisms was found. Conclusion: These results provide evidence for different and independent gene expression in phlegmonous and gangrenous appendicitis in general, but also suggest distinct immunological patterns for the respective entities. In particular, the findings are compatible with previous evidence of spontaneous resolution in phlegmonous and progressive disease in gangrenous appendicitis

    Transösophageale Echokardiographie zum Ausschluss von Thromben vor Elektrokardioversion bei Vorhofflimmern

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    Im nicht selektionierten Patientengut eines Akutkrankenhauses ist das Vorhofflimmern eine häufige Herzrhythmusstörung. Die Ergebnisse dieser Studie haben gezeigt, dass die TEE-gesteuerte elektrische Kardioversion - auch bei Patienten mit einem sehr hohen kardio-embolischen Risiko - ein sicheres Verfahren zur Wiederherstellung des Sinusrhythmus im klinischen Alltag ist. Bei Patienten mit einer arteriellen Hypertonie waren die AT1-Antagonisten sowohl hinsichtlich des Kardioversionserfolges als auch zur Rezidivprophylaxe den anderen Antihypertensiva zum Teil signifikant überlegen. Die Unterschiede waren noch deutlicher, wenn bereits eine hypertensive Herzerkrankung vorlag. Ob Patienten mit Vorhofflimmern und einer arteriellen Hypertonie besonders von einer antihypertensiven Therapie mit einem AT1-Blocker profitieren, müsste durch weitere prospektive Studien geklärt werden

    Health-Promoting and Sustainable Behavior in University Students in Germany: A Cross-Sectional Study

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    Health-promoting and sustainable behaviors, such as active transportation and sustainable diets, are associated with positive effects on human health and the environment. In order to unlock the potential of university students as key actors and multipliers, it is of interest to investigate their level of knowledge about the health effects of climate change and their willingness toward and implementation of health-promoting and sustainable behaviors. In November 2021, an online survey was conducted among students at the University of Regensburg, Germany. A total of 3756 participants (response rate 18%; mean age 23 years; 69% women) provided valid data. A large proportion of medical students (48%) considered themselves well-informed about the health-related effects of climate change, while only a small proportion (22%) of students within economic/computer/data sciences and law felt informed. Most participants knew about the impact of climate change on malnutrition (78%), but considerably fewer were aware of its impact on cardiovascular diseases (52%). Participants who considered themselves informed were consistently more willing to engage in climate-friendly behavior, and this willingness was also reflected in their actions, as they simultaneously promoted a healthy lifestyle. Across all academic disciplines, there is a strong need for knowledge transfer regarding topics that combine health and sustainable development

    Optimal Resting-Growth Strategies of Microbial Populations in Fluctuating Environments

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    Bacteria spend most of their lifetime in non-growing states which allow them to survive extended periods of stress and starvation. When environments improve, they must quickly resume growth to maximize their share of limited nutrients. Cells with higher stress resistance often survive longer stress durations at the cost of needing more time to resume growth, a strong disadvantage in competitive environments. Here we analyze the basis of optimal strategies that microorganisms can use to cope with this tradeoff. We explicitly show that the prototypical inverse relation between stress resistance and growth rate can explain much of the different types of behavior observed in stressed microbial populations. Using analytical mathematical methods, we determine the environmental parameters that decide whether cells should remain vegetative upon stress exposure, downregulate their metabolism to an intermediate optimum level, or become dormant. We find that cell-cell variability, or intercellular noise, is consistently beneficial in the presence of extreme environmental fluctuations, and that it provides an efficient population-level mechanism for adaption in a deteriorating environment. Our results reveal key novel aspects of responsive phenotype switching and its role as an adaptive strategy in changing environments

    “I should have …”:A Photovoice Study With Women Who Have Lost a Man to Suicide

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    While the gendered nature of suicide has received increased research attention, the experiences of women who have lost a man to suicide are poorly understood. Drawing on qualitative photovoice interviews with 29 women who lost a man to suicide, we completed a narrative analysis, focused on describing the ways that women constructed and accounted for their experiences. We found that women’s narratives drew upon feminine ideals of caring for men’s health, which in turn gave rise to feelings of guilt over the man’s suicide. The women resisted holding men responsible for the suicide and tended to blame themselves, especially when they perceived their efforts to support the man as inadequate. Even when women acknowledged their guilt as illogical, they were seemingly unable to entirely escape regret and self-blame. In order to reformulate and avoid reifying feminine ideals synonymous with selflessly caring for others regardless of the costs to their own well-being, women’s postsuicide bereavement support programs  hould integrate a critical gender approach

    Toll-like receptor 4 signaling in liver injury and hepatic fibrogenesis

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    Toll-like receptors (TLRs) are a family of transmembrane pattern recognition receptors (PRR) that play a key role in innate and adaptive immunity by recognizing structural components unique to bacteria, fungi and viruses. TLR4 is the most studied of the TLRs, and its primary exogenous ligand is lipopolysaccharide, a component of Gram-negative bacterial walls. In the absence of exogenous microbes, endogenous ligands including damage-associated molecular pattern molecules from damaged matrix and injured cells can also activate TLR4 signaling. In humans, single nucleotide polymorphisms of the TLR4 gene have an effect on its signal transduction and on associated risks of specific diseases, including cirrhosis. In liver, TLR4 is expressed by all parenchymal and non-parenchymal cell types, and contributes to tissue damage caused by a variety of etiologies. Intact TLR4 signaling was identified in hepatic stellate cells (HSCs), the major fibrogenic cell type in injured liver, and mediates key responses including an inflammatory phenotype, fibrogenesis and anti-apoptotic properties. Further clarification of the function and endogenous ligands of TLR4 signaling in HSCs and other liver cells could uncover novel mechanisms of fibrogenesis and facilitate the development of therapeutic strategies
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