512 research outputs found

    Expression of ECM proteins fibulin-1 and -2 in acute and chronic liver disease and in cultured rat liver cells

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    Fibulin-2 has previously been considered as a marker to distinguish rat liver myofibroblasts from hepatic stellate cells. The function of other fibulins in acute or chronic liver damage has not yet been investigated. The aim of this study has been to evaluate the expression of fibulin-1 and -2 in models of rat liver injury and in human liver cirrhosis. Their cellular sources have also been investigated. In normal rat liver, fibulin-1 and -2 were both mainly present in the portal field. Fibulin-1-coding transcripts were detected in total RNA of normal rat liver, whereas fibulin-2 mRNA was only detected by sensitive, real-time quantitative polymerase chain reaction. In acute liver injury, the expression of fibulin-1 was significantly increased (17.23-fold after 48 h), whereas that of fibulin-2 was not modified. The expression of both fibulin-1 and -2 was increased in experimental rat liver cirrhosis (19.16- and 26.47-fold, respectively). At the cellular level, fibulin-1 was detectable in hepatocytes, “activated” hepatic stellate cells, and liver myofibroblasts (2.71-, 122.65-, and 469.48-fold over the expression in normal rat liver), whereas fibulin-2 was restricted to liver myofibroblasts and was regulated by transforming growth factor beta-1 (TGF-ÎČ1) in 2-day-old hepatocyte cultures and in liver myofibroblasts. Thus, fibulin-1 and -2 respond differentially to single and repeated damaging noxae, and their expression is differently present in liver cells. Expression of the fibulin-2 gene is regulated by TGF-ÎČ1 in liver myofibroblasts

    Sagnac Interferometer Enhanced Particle Tracking in Optical Tweezers

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    A setup is proposed to enhance tracking of very small particles, by using optical tweezers embedded within a Sagnac interferometer. The achievable signal-to-noise ratio is shown to be enhanced over that for a standard optical tweezers setup. The enhancement factor increases asymptotically as the interferometer visibility approaches 100%, but is capped at a maximum given by the ratio of the trapping field intensity to the detector saturation threshold. For an achievable visibility of 99%, the signal-to-noise ratio is enhanced by a factor of 200, and the minimum trackable particle size is 2.4 times smaller than without the interferometer

    Barriers and Ways Forward to Climate Risk Management Against Indirect Effects of Natural Disasters: A Case Study on Flood Risk in Austria

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    Natural disasters, such as floods, can have severe consequences, especially as economies are becoming ever more interlinked and complex so that the cascading effects of disasters can amplify direct impacts. These trends are expected to continue in the future due to climate change and changing socio-economic structures. It is therefore important to promote climate risk management strategies that also deal with indirect effects due to natural disaster events in a proactive manner. However, there is a lack of studies which investigate the agents involved in climate risk management geared towards the indirect effects of disasters and how these indirect effects are or can be dealt with. We address this gap via a detailed case study of the Austrian flood risk management apparatus. Based on a detailed stakeholder analysis, we compile a stakeholder map of those potentially involved in indirect flood risk management as well as the relationships (or the lack thereof) among them. We further discuss current and future indirect risk management strategies and corresponding implementation barriers. Finally, based on the results obtained from the stakeholder process, we discuss and suggest possible ways forward to overcome these barriers to enable proactive management strategies for indirect climate risks. We find that although indirect risks are being considered in the Austrian flood risk management, they are managed to a marginal degree. To remedy this, we call for increased efforts in data collection, modelling and awareness raising and the revision of current financial as well as institutional structures. Greater focus should be put on interdependencies within systems as well as the adoption of long-term visions for establishing more integrated climate risk management against indirect effects

    StabilitÀt von Herzglykosiden in wÀssrigen bzw. wÀssrig fermentierten Extrakten aus der Meerzwiebel (Drimia maritima (L.) Stearn)

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    In der vorliegenden Studie wurden ein rein wĂ€ssriger Extrakt und ein wĂ€ssrig fermentierter Extrakt, hergestellt nach dem Homöopathischem Arzneibuch (HAB), aus der Meerzwiebel (Drimia maritima (L.) Stearn) bei unterschiedlichen Temperatur- und Lichtbedingungen gelagert. In regelmĂ€ĂŸigen AbstĂ€nden wurde die StabilitĂ€t der Herzglykoside in diesen Extrakten mittels HPLC-DAD-MSn bewertet. Die geringsten Abbauraten der Einzelkomponenten wurden bei einer Lagerung im Dunkeln bei 5 °C ermittelt. Schon eine Temperaturerhöhung auf 20 °C beschleunigte den Abbau bzw. die Metabolisierung der Bufadienolide. Die geringste StabilitĂ€t wurde unter Belichtung bei 20 °C ermittelt. Außerdem war ein deutlicher Unterschied zwischen den auf unterschiedliche Weisen gewonnenen Extrakten beobachtbar. So wiesen die Herzglykoside im Extrakt, der nach HAB hergestellt wurde, eine deutliche höhere StabilitĂ€t unter allen Lagerbedingungen auf. Stichwörter: Meerzwiebel, Herzglykoside, StabilitĂ€t, Belichtung, Pflanzenextrakt, Drimia maritima (L.) Stearn Stability of cardiac glycosides in aqueous and fermented aqueous extracts from sea squill (Drimia maritima L. Stearn)In the present study an aqueous and a fermented aqueous extract, obtained according to the German Homoeopathic Pharmacopoeia (GHP), from sea squill (Drimia maritima (L.) Stearn) were stored under different light and temperature conditions. Stability of cardiac glycosides in these extracts was evaluated periodically by HPLC-DAD-MS. Lowest degradation rates of individual compounds were observed upon storage at 5 °C in the dark. Increasing the temperature at 20 °C accelerated compound degradation and the formation of bufadienolide metabolites. Poorest stability was found upon storage at 20 °C with light exposure. Furthermore, clear-cut differences were observed between the extracts obtained according to different protocols. Stability of cardiac glycosides in the extract obtained according to the GHP was generally improved, irrespective of the storage conditions. Keywords: sea squill, cardiac glycosides, stability, light exposure, plant extract, Drimia maritima (L.) Stear

    Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

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    A camphor-derived sulfonimine with a conjugated carbonyl group, oxoimine 1 (O2SNC10H13O), reacts with amino acids (glycine, L-alanine, L-phenylalanine, L-leucine) to form a compound O2SNC10H13NC10H14NSO2 (2) which was characterized by spectroscopic means (MS and NMR) and supported by DFT calculations. The product, a single diastereoisomer, contains two oxoimine units connected by a –N= bridge, and thus has a structural analogy to the colored product Ruhemann®s purple obtained by the ninhydrin reaction with amino acids. A plausible reaction mechanism that involves zwitterions, a Strecker degradation of an intermediate imine and water-catalyzed tautomerizations was developed by means of DFT calculations on potential transition states

    Revealing indirect risks in complex socioeconomic systems: A highly detailed multi‐model analysis of flood events in Austria

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    Cascading risks that can spread through complex systems have recently gained attention. As it is crucial for decision-makers to put figures on such risks and their interactions, models that explicitly capture such interactions in a realistic manner are needed. Climate related hazards often cascade through different systems, from physical to economic and social systems, causing direct but also indirect risks and losses. Despite their growing importance in the light of ongoing climate change and increasing global connections, such indirect risks are not well understood. Applying two fundamentally different economic models—a computable general equilibrium model and an agent-based model—we reveal indirect risks of flood events. The models are fed with sector-specific capital stock damages, which constitutes a major methodological improvement. We apply these models for Austria, a highly flood exposed country with strong economic linkages. A key finding is that flood damages pose very different indirect risks to different sectors and household groups (distributional effects) in the short and long-term. Our results imply that risk management should focus on specific societal subgroups and sectors. We provide a simple metric for indirect risk, showing how direct and indirect losses are related. This can provide new ways forward in risk management, for example, focusing on interconnectedness of sectors and agents within different risk-layers of indirect risk. Although we offer highly relevant leverage points for indirect risk management in Austria, the methodology of analyzing indirect risks can be transferred to other regions

    Indirect flood risk management in Austria: Challenges and ways forward

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    Natural disaster risks are among the greatest threats of the 21st century putting political, social and economic systems increasingly under pressure and at risk of instability (UNDRR/CRED 2020). Especially in recent years, the cascading effects and risks associated with such events have received great attention as economic losses and consequences have mounted (Handmer et al. 2020; Reichstein et al. 2021). Due to increasingly complex economic networks and interdependencies, natural disasters can result in large ripple effects including business or supply chain interruptions, changes in economic productivity or increased indebtedness. These so-called indirect losses can amount to or even exceed direct damages (Koks et al. 2015; Dottori et al. 2018). Climate change exacerbates the intensity and frequency of flood events. Accompanied by socioeconomic changes this leads to increasing flood damages. Therefore, more holistic and long-term disaster risk management (DRM) strategies that tackle indirect effects and which take into account climate change effects are called for. To implement these strategies, we require a deeper understanding of who could be involved in indirect flood risk management (FRM), which management strategies are already implemented and which should be implemented in the future, as well as what are the corresponding implementation barriers. These issues are addressed in this fact sheet in the context of Austrian climate risk management strategies discussing how indirect risks from floods are currently considered and how they could be proactively integrated on various scales (the discussion is based on Reiter et al. 2022)

    Modelling the indirect impacts of flood risks in Austria

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    Imaging local diffusion in microstructures using NV-based pulsed field gradient NMR

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    Understanding diffusion in microstructures plays a crucial role in many scientific fields, including neuroscience, cancer or energy research. While magnetic resonance (MR) methods are the gold standard for diffusion measurements, spatial encoding in MR imaging has limitations. Here, we introduce nitrogen-vacancy (NV) center based nuclear magnetic resonance (NMR) spectroscopy as a powerful tool to probe diffusion with an optical readouts. We have developed an experimental scheme combining pulsed gradient spin echo (PGSE) with optically detected NV-NMR spectroscopy, which allows for the local quantification of molecular diffusion and flow within microscopic sample volumes. We demonstrate correlated optical imaging with spatially resolved PGSE NV-NMR experiments probing anisotropic water diffusion within a model microstructure. Our optically detected PGSE NV-NMR technique opens up prospects for extending the current capabilities of investigating diffusion processes with the future potential of probing single cells, tissue microstructures, or ion mobility in thin film materials for battery applications.Comment: 37 pages, 5 figures, 2 table

    Risk management against indirect risks from disasters: A multi-model and participatory governance framework applied to flood risk in Austria

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    Indirect effects resulting from natural disasters, such as the follow-on consequences of initial destruction, are attracting growing attention. This is because economic losses in the aftermath of disaster events have escalated in recent years and are expected to continue to rise in the future. Despite this, the primary focus of most countries’ disaster risk management approaches remains centered on mitigating the direct effects of such events, with little attention being paid to strategies aimed explicitly at reducing indirect effects. As a result, there are limited practical solutions available for reducing these indirect damages. Most efforts remain theoretical, lacking real-world testing of frameworks specifically designed to reduce indirect risks. To address this gap, this paper aims to illuminate the issue by proposing and empirically testing how existing risk management frameworks designed for direct risks could be expanded to encompass indirect effects as well. In doing so, we create and use a framework to manage indirect risks in a collaborative process for dealing with major flood risk in Austria. We test specific challenges and explore ways to integrate the management of these indirect risks in a complex real-world scenario. Our findings suggest that linking indirect and direct risk management can be achieved with relatively modest effort. A precise systems definition proves particularly beneficial in this regard, as it can link disaster risk related dimensions with non-disaster related targets. This approach thereby opens up the possibility to explicitly include multiple dividends in the decision-making process about indirect risk management strategies
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