922 research outputs found

    Lossy Compression of Electron Diffraction Patterns for Ptychography via Change of Basis

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    Ptychography is a computational imaging technique that has risen in popularity in the x-ray and electron microscopy communities in the past half decade. One of the reasons for this success is the development of new high performance electron detectors with increased dynamic range and readout speed, both of which are necessary for a successful application of this technique. Despite the advances made in computing power, processing the recorded data remains a challenging task, and the growth in data rate has made the size of the resulting datasets a bottleneck for the whole process. Here we present an investigation into lossy compression methods for electron diffraction patterns that retain the necessary information for ptychographic reconstructions, yet lead to a decrease in data set size by three or four orders of magnitude. We apply several compression methods to both simulated and experimental data - all with promising results

    Der Wettbewerb um die lingua academica: Gegenüberstellung einer linguistischen und einer geopolitischen Perspektive zur Entwicklung internationaler Wissenschaftssprachen

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    The fact that today’s scientists are linguistically confined to a monoglot world when publishing on an international level has given rise to concern in the academic community around the globe. The disadvantages of one vehicular language dominating scientific research worldwide have been discussed extensively by German-speaking linguists who advocate scientific plurilingualism for international publications. Against this background, the present study seeks to shed light on the dominant position of English as the global lingua academica by juxtaposing a linguistic and a geopolitical perspective. The linguistic perspective is based on an analysis, which compares the syntax, word formation possibilities, and etymological background of terms used in the abstracts of English and German academic papers that were submitted at the University of Vienna. The findings reveal that based on these criteria, English might be considered more advantageous in fulfilling the role of the global scientific language. H   The fact that today’s scientists are linguistically confined to a monoglot world when publishing on an international level has given rise to concern in the academic community around the globe. The disadvantages of one vehicular language dominating scientific research worldwide have been discussed extensively by German-speaking linguists who advocate scientific plurilingualism for international publications. Against this background, the present study seeks to shed light on the dominant position of English as the global lingua academica by juxtaposing a linguistic and a geopolitical perspective. The linguistic perspective is based on an analysis, which compares the syntax, word formation possibilities, and etymological background of terms used in the abstracts of English and German academic papers that were submitted at the University of Vienna. The findings reveal that based on these criteria, English might be considered more advantageous in fulfilling the role of the global scientific language. H                   &nbsp

    In Silico Study of Local Electrical Impedance Measurements in the Atria - Towards Understanding and Quantifying Dependencies in Human

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    Background: Electrical impedance measurements have become an accepted tool for monitoring intracardiac radio frequency ablation. Recently, the long-established generator impedance was joined by novel local impedance measurement capabilities with all electrical circuit terminals being accommodated within the catheter. Objective: This work aims at in silico quantification of distinct influencing factors that have remained challenges due to the lack of ground truth knowledge and the superposition of effects in clinical settings. Methods: We introduced a highly detailed in silico model of two local impedance enabled catheters, namely IntellaNav MiFiâ„¢ OI and IntellaNav Stablepointâ„¢, embedded in a series of clinically relevant environments. Assigning material and frequency specific conductivities and subsequently calculating the spread of the electrical field with the finite element method yielded in silico local impedances. The in silico model was validated by comparison to in vitro measurements of standardized sodium chloride solutions. We then investigated the effect of the withdrawal of the catheter into the transseptal sheath, catheter-tissue interaction, insertion of the catheter into pulmonary veins, and catheter irrigation. Results: All simulated setups were in line with in vitro experiments and in human measurements and gave detailed insight into determinants of local impedance changes as well as the relation between values measured with two different devices. Conclusion: The in silico environment proved to be capable of resembling clinical scenarios and quantifying local impedance changes. Significance: The tool can assists the interpretation of measurements in humans and has the potential to support future catheter development

    A peptide mimic of the chemotaxis inhibitory protein of Staphylococcus aureus: towards the development of novel anti-inflammatory compounds

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    Complement factor C5a is one of the most powerful pro-inflammatory agents involved in recruitment of leukocytes, activation of phagocytes and other inflammatory responses. C5a triggers inflammatory responses by binding to its G-protein-coupled C5a-receptor (C5aR). Excessive or erroneous activation of the C5aR has been implicated in numerous inflammatory diseases. The C5aR is therefore a key target in the development of specific anti-inflammatory compounds. A very potent natural inhibitor of the C5aR is the 121-residue chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS). Although CHIPS effectively blocks C5aR activation by binding tightly to its extra-cellular N terminus, it is not suitable as a potential anti-inflammatory drug due to its immunogenic properties. As a first step in the development of an improved CHIPS mimic, we designed and synthesized a substantially shorter 50-residue adapted peptide, designated CHOPS. This peptide included all residues important for receptor binding as based on the recent structure of CHIPS in complex with the C5aR N terminus. Using isothermal titration calorimetry we demonstrate that CHOPS has micromolar affinity for a model peptide comprising residues 7–28 of the C5aR N terminus including two O-sulfated tyrosine residues at positions 11 and 14. CD and NMR spectroscopy showed that CHOPS is unstructured free in solution. Upon addition of the doubly sulfated model peptide, however, the NMR and CD spectra reveal the formation of structural elements in CHOPS reminiscent of native CHIPS

    Comparison of treatment response, remission rate and drug adherence in polyarticular juvenile idiopathic arthritis patients treated with etanercept, adalimumab or tocilizumab

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    Background Treatment response, remission rates and compliance in patients with polyarticular juvenile idiopathic arthritis (polyJIA) treated with adalimumab, etanercept, or tocilizumab were analyzed in clinical practice. Methods Data collected in the German BIKER registry were analyzed in patients with polyJIA who started treatment with approved biologics, adalimumab, etanercept or tocilizumab, from 2011 to 2015. Baseline patient characteristics, treatment response, safety and drug survival were compared. Results Two hundred thirty- six patient started adalimumab, 419 etanercept and 74 tocilizumab, with differences in baseline patient characteristics. Baseline Juvenile Disease Activity Score (JADAS)10 (mean ± SD) in the adalimumab/etanercept/tocilizumab cohorts was 12.1+/−7.6, 13.8 ± 7.1 and 15.1 ± 7.4, respectively (adalimumab vs etanercept, p = 0.01), and Childhood Health Assessment Questionnaire (CHAQ)-disability index scores was 0.43 ± 0.58, 0.59 ± 0.6 and 0.63 ± 0.55, respectively (adalimumab vs etanercept, p < 0.001). Uveitis history was more frequent in the adalimumab cohort (OR 5.73; p < 0.001). Balanced patients’ samples were obtained by a generalized propensity score to adjust for baseline differences. Pediatric ACR30/50/70/90 criterion improvement after 3 months treatment was achieved by 68%/60%/42%/24% in the etanercept cohort, 67%/59%/43%/27% in the adalimumab cohort and 61%/52%/35%/26% in the tocilizumab cohort. At 24 months, JADAS minimal disease activity was achieved in 52.4%/61.3%/52.4% and JADAS remission in 27.9%/34.8%/27.9% patients in the adalimumab/etanercept/tocilizumab cohorts, respectively. Etanercept was used in 95.5% of patients as a first biologic, adalimumab in 50.8% and tocilizumab in 20.2%. There were no important differences in efficacy between first-line and second-line use of biologics. In total 60.4%/49.4%/31.1% patients discontinued adalimumab/etanercept/tocilizumab, respectively (HR for adalimumab 1.67; p < 0.001; HR for tocilizumab 0.35; p = 0.001). Drug survival rates did not differ significantly in patients on biologic monotherapy compared with combination therapy with methotrexate. Over 4 years observation under etanercept/adalimumab/tocilizumab, 996/386/103 adverse events, and 148/119/26 serious adverse events, respectively, were reported. Conclusions In clinical practice, etanercept is most frequently used as first-line biologic. Adalimumab/etanercept/tocilizumab showed comparable efficacy toward polyJIA. Overall, tolerance was acceptable. Interestingly, compliance was highest with tocilizumab and lowest with adalimumab. This study provides the first indication for the comparison of different biologic agents in polyarticular JIA based on observational study data with all their weaknesses and demonstrates the need for well-controlled head-to-head studies for confirmation

    The effect of the thioether-bridged, stabilized angiotensin-(1-7) analogue cyclic Ang-(1-7) on cardiac remodeling and endothelial function in rats with myocardial infarction

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    Modulation of renin-angiotensin system (RAS) by angiotensin-(17) (Ang-(17)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(17) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(17) called cyclic Ang-(17) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 μg/kg/h cAng-(17) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8 and was not changed by cAng-(17) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(17) to sham levels. In addition, cAng-(17) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(17) is a promising new agent in treatment of myocardial infarction and warrant further research.</p
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