107 research outputs found
Improved Stratification of Autonomic Regulation for risk prediction in post-infarction patients with preserved left ventricular function (ISAR-Risk)
Aims To investigate the combination of heart rate turbulence (HRT) and deceleration capacity (DC) as risk predictors in post-infarction patients with left ventricular ejection fraction (LVEF) > 30%. Methods and results We enrolled 2343 consecutive survivors of acute myocardial infarction (MI) (30% (cumulative 5-year mortality rates of 37.9% and 7.8%, respectively). Among patients with LVEF > 30%, SAF identified another high-risk group of 117 patients with 37 deaths (cumulative 5-year mortality rates of 38.6% and 6.1%, respectively). Merging both high-risk groups (i.e. LVEF ≤ 30% and/or SAF) doubled the sensitivity of mortality prediction compared with LVEF ≤ 30% alone (21.1% vs. 42.1%, P 30%, SAF identifies a high-risk group equivalent in size and mortality risk to patients with LVEF ≤ 30%
Carbon atom reactivity with amorphous solid water: H2O-catalyzed formation of H2CO
NWOTheoretical Chemistr
Carbon Atom Reactivity with Amorphous Solid Water: H2O-Catalyzed Formation of H2CO
We report new computational and experimental evidence of an efficient and astrochemically relevant formation route to formaldehyde (H2CO). This simplest carbonylic compound is central to the formation of complex organics in cold interstellar clouds and is generally regarded to be formed by the hydrogenation of solid-state carbon monoxide. We demonstrate H2CO formation via the reaction of carbon atoms with amorphous solid water. Crucial to our proposed mechanism is a concerted proton transfer catalyzed by the water hydrogen bonding network. Consequently, the reactions 3C + H2O → 3HCOH and 1HCOH → 1H2CO can take place with low or without barriers, contrary to the high-barrier traditional internal hydrogen migration. These low barriers (or the absence thereof) explain the very small kinetic isotope effect in our experiments when comparing the formation of H2CO to D2CO. Our results reconcile the disagreement found in the literature on the reaction route C + H2O → H2CO. © 2021 The Authors. Published by American Chemical Society.Ko-Ju Chuang and Melissa McClure are greatly thanked for stimulating discussions. We also thank the anonymous reviewers for their suggestions. Computer time was granted by the state of Baden-Württemberg through bwHPC and the German Research Foundation (DFG) through grant no. INST 40/467-1FUGG is greatly acknowledged. G.M thanks the Alexander von Humboldt Foundation for a postdoctoral research grant. We thank the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for supporting this work by funding EXC 2075-390740016 under Germany’s Excellence Strategy. T.L. is grateful for support from the Dutch Research Council (NWO) via a VENI fellowship (Grant No. 722.017.008). Astrochemistry in Leiden is supported by the Dutch Astrochemistry Network (DAN) II (Project No. 648.000.029). G.F. acknowledges financial support from the Russian Ministry of Science and Higher Education via the State Assignment Contract. FEUZ-2020-0038. This work has been supported in part by the Danish National Research Foundation through the Center of Excellence “InterCat” (Grant Agreement No.: DNRF150)
Comparative expression pattern of Matrix-Metalloproteinases in human glioblastoma cell-lines and primary cultures
<p>Abstract</p> <p>Background</p> <p>Glioblastomas (GBM), the most frequent malignant brain tumors in adults, are characterized by an aggressive local growth pattern and highly invasive tumor cells. This invasion is facilitated by expression of matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases. They mediate the degradation of protein components of the extracellular matrix. Twenty-three family members are known. Elevated levels of several of them have been reported in GBM. GBM cell-lines are used for <it>in vitro </it>studies of cell migration and invasion. Therefore, it is essential to know their MMP expression patterns. Only limited data for some of the cell-lines are published, yet. To fill the gaps in our knowledge would help to choose suitable model systems for analysis of regulation and function of MMPs during GBM tumorigenesis, cell migration and invasion.</p> <p>Findings</p> <p>We analysed MMP-1, -8, -9, -10, -11, -13, -17, -19, -20, -21, -23, -24, -26, -27, and MMP-28 expression in seven GBM cell-lines (SNB-19, GaMG, U251, U87, U373, U343, U138) and in four primary cell cultures by semiquantitative RT-PCR, followed changes in the MMP expression pattern with increasing passages of cell culture and examined the influence of TNF-α and TGF-β1 stimulation on the expression of selected MMPs in U251 and U373 cells.</p> <p>MMP-13, -17, -19 and -24 were expressed by all analyzed cell-lines, whereas MMP-20 and MMP-21 were not expressed by any of them. The other MMPs showed variable expression, which was dependent on passage number. Primary cells displayed a similar MMP-expression pattern as the cell-lines. In U251 and U373 cells expression of MMP-9 and MMP-19 was stimulated by TNF-α. MMP-1 mRNA expression was significantly increased in U373 cells, but not in U251 cells by this cytokine. Whereas TGF-β1 had no impact on MMP expression in U251 cells, it significantly induced MMP-11 and MMP-24 expression in U373 cells.</p> <p>Conclusions</p> <p>Literature-data and our own results suggest that the expression pattern of MMPs is highly variable, dependent on the cell-line and the cell-culture conditions used and that also regulation of MMP expression by cytokines is cell-line dependent. This is of high impact for the transfer of cell-culture experiments to clinical implementation.</p
Avemar and Echinacea extracts enhance mobilization and homing of CD34+ stem cells in rats with acute myocardial infarction
Visible spectrum quantum light sources based on InxGa1–xN/GaN Quantum Dots
We present a method for designing quantum
light sources, emitting in the visible band, using wurtzite
InxGa1−xN quantum dots (QDs) in a GaN matrix. This system
is significantly more versatile than previously proposed
arsenide- and phosphide-based QDs, having a tuning range
exceeding 1 eV. The quantum mechanical configuration
interaction method, capturing the fermionic nature of
electrons and associated quantum effects explicitly, is used to
find shapes and compositions of dots to maximize the
excitonic dipole matrix element and optimize the biexciton
binding energy. These results provide QD morphologies
tailored for either bright single-photon emission or entangledphoton-
pair emission at any given wavelength in the visible
spectrum
A Petri Net Approach for the Performance Analysis of Business Processes
Recently, many companies have realized that their organization needs to be improved in order to enhance flexibility, efficiency, and effectiveness. Business Process Re-engineering has become the new organization paradigm to reconstitute profitability and competitiveness. Additionally, workflow management systems promise to provide a conceptual framework to describe and automate workflow. Analysts are asking for methods to evaluate alternative process designs for performance objectives, such as cycle time and throughput. These measures are dependent on the dynamic behavior of a process and can hardly be derived by traditional methods. In this paper we will outline an approach to model the dynamic behavior of business processes by Stochastic Petri nets. Our aim is to provide workflow management systems with an analytical evaluation component. We will summarize the problems we encountered following our approach to give directions for further research
Determination of alpha- and beta-adrenoceptor-affinities to the highly potent extraneuronal catecholamine uptake-2 inhibitors decynium 22 and disprocynium 24
Pharmacokinetic and alpha 1 -adrenoceptor antagonistic properties of two cyanine-type inhibitors of extraneuronal monamine transport
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