10 research outputs found

    Detectability of simulated apical lesions on mandibular premolars and molars between radiographic intraoral and cone-beam computed tomography images: an ex vivo study.

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    Adequate endodontic diagnostic is essential when making a therapy decision. Radiographic imagining acquisition methods (IAMs) are fundamental apical lesions of endodontic (ALE) origin diagnose tool. Thus, the aim of this research was to compare the simulated apical lesions (SALs) diagnose potential of digital intraoral radiography (DIR) and cone-beam computed tomography (CBCT), if there is a relationship between the IAMs, SALs-depth and their correct diagnose likelihood in human mandibular specimens' datasets. 1024 SALs were prepared in cancellous and cortical bone with different penetration depths. The SALs-stages were radiographed with CBCT and DIR. The IAMs were randomly evaluated by 16 observers in two trials. Possible SAL findings were analyzed according to a five-point scale. The null hypothesis established that SALs detection accuracy does not differ between CBCT and DIR. Significantly differences (first 0.935 and second trial 0.960) were found for the CBCT area under the curve when compared with the DIR (first 0.859 and second trial 0.862) findings. SALs of smaller size were earlier detected by CBCT. In SALs without cortical involvement the probability of detection increased from 90 to 100%. The SALs-depth had the highest detectability influence on cancellous bone lesions and CBCT SALs detectability was 84.9% higher than with DIR images. The CBCT diagnose reproducibility was higher than the one of DIR (Kappa CBCT 75.7-81.4%; DIR 53.4-57.1%). Our results showed that CBCT has a higher SALs IAM diagnosing accuracy and that SALs detection accuracy incremented as the SALs-size increased

    Risk governance in organizations

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    Dieses Buch dokumentiert 10 Jahre Risk-Governance-Forschung an der Universität Siegen. In 50 Beiträgen reflektieren Forscher und Praktiker Risk Governance vor dem Hintergrund ihrer eigenen Forschungen und/oder Erfahrungen und geben jeweils einen Entwicklungsimpuls für die Zukunft der Risk Governance. Das Buch zeigt die große Bandbreite und Tiefe des Forschungsgebietes auf und diskutiert Grundannahmen, Implementierungsfragen, die Rolle der Risk Governance als Transformationsmotor, ihre Wirkung in den verschiedenen betrieblichen Funktionen, Entwicklungsperspektiven und den Beitrag der Risk Governance zu einer nachhaltigen Ausrichtung von Unternehmen.This book documents 10 years of risk governance research at the University of Siegen. In 50 contributions, researchers and practitioners reflect on risk governance against the background of their own research and/or experience and provide a development impetus for the future of risk governance. The book shows the wide range and depth of the research field and discusses basic assumptions, implementation issues, the role of risk governance as transformation engine, its impact in the various operational functions, development perspectives, and the contribution of risk governance to a sustainable orientation of companies

    Copper Nanoparticles with High Index Facets on Basal and Vicinal ZnO Surfaces

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    We investigated the orientation and morphology of Cu nanoparticles grown under ultrahigh-vacuum conditions on ZnO(0001), ZnO(000-1), and ZnO(10-14) single crystal surfaces by scanning tunneling microscopy, high-energy grazing incidence X-ray diffraction, low-energy electron diffraction, and scanning electron microscopy. The (111) oriented Cu NPs on basal ZnO showed only small area fractions of high indexed Cu(225) and Cu(331) facets. Cu NPs grown on ZnO(101̅4) show alignment of Cu [111] with the ZnO [0001] direction, which is at an angle of 24.8° to the ZnO(10-14) surface normal. Because of this tilt, the NPs exhibit a shape with a larger fraction of high indexed facets such as (335), (221), (113), and (55-1). In addition, the direct interaction of subsequent Cu(111) planes to the underlying substrate results in unequal amounts of ABCA and ACBA stacked NPs. Small NPs are found to interact strongly with the vicinal surface, giving rise to a surface corrugation with a multiple of the surface step distance. The high density of low-coordinated Cu surface atoms potentially increases the overall catalytic activity for methanol synthesis and CO2 hydrogenation reactions

    Macrophage Inflammatory Markers Are Associated With Subclinical Carotid Artery Disease in Women With Human Immunodeficiency Virus or Hepatitis C Virus Infection

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    ObjectiveInfection with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) may be associated with atherosclerosis and vascular disease. Macrophages are a major component of atherosclerotic plaque, and classically activated (M1) macrophages contribute to plaque instability. Our goal was to identify plasma biomarkers that reflect macrophage inflammation and are associated with subclinical atherosclerosis.Approach and resultsWe tested whether M1 macrophages produce galectin-3-binding protein in vitro. Then, we measured galectin-3-binding protein and the soluble macrophage biomarkers soluble cluster of differentiation (CD) 163 and soluble CD14 in 264 participants in the Women's Interagency HIV Study. Women were positive for HIV, HCV, both, or neither (66 in each group, matched for age, race/ethnicity, and smoking status). Carotid artery disease was assessed by ultrasound measurement of right distal common carotid artery intima-media thickness, distensibility, and presence of atherosclerotic lesions (intima-media thickness >1.5 mm). Plasma galectin-3-binding protein was higher in HCV+ than HCV- women (P<0.01) but did not differ by HIV status. The 3 inflammatory macrophage markers were significantly correlated with each other and negatively correlated with CD4+ counts in HIV-infected women. We defined a macrophage score as 1, 2, or 3 biomarkers elevated above the median. In models adjusted for traditional risk factors, higher macrophage scores were significantly associated with increased atherosclerotic lesions and lower carotid distensibility. Receiver-operator curve analysis of lesions revealed that the markers added predictive value beyond traditional risk factors and C-reactive protein.ConclusionsThe macrophage inflammatory markers galectin-3-binding protein, soluble CD163, and soluble CD14 are significantly associated with carotid artery disease in the setting of HIV and HCV infection

    Ambient Pressure Oxidation-Reduction Dynamics of Cu/ZnO Model Catalysts for Methanol Synthesis

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    We investigated Cu/ZnO model catalysts for methanol synthesis to obtain an atomistic picture of activation and deactivation processes under in situ oxidizing and reducing conditions. We have investigated Cu nanoparticles with different shapes and aspect ratios grown epitaxially on basal and vicinal ZnO surfaces at elevated gas pressures by high energy grazing incidence X-ray diffraction and ambient pressure X-ray photoelectron spectroscopy (AP-XPS). We find that the Cu nanoparticles are fully oxidized to Cu2O under atmospheric conditions at room temperature. During oxidation, they maintain their epitaxy on basal ZnO (000-1) surfaces, whereas on the vicinal ZnO (10-14) surface, the nanoparticles undergo a coherent tilt. We find that the oxidation process is fully reversible under H2 flow at 500 K, resulting in predominantly well-aligned nanoparticles on the basal surfaces, whereas a random orientation is preferred for the (10-14) surface. Under CO2 flow, no diffraction signal from the nanoparticles is detected, pointing to their completely disordered state. The AP-XPS results are in line with the formation of CuO. The analysis of the substrate crystal truncation rods evidences the stability of basal ZnO surfaces under all gas conditions. No proof for Cu-Zn alloy formation is found. Scanning electron microscopy images show that massive mass transport has set in, leading to the formation of larger agglomerates, which is detrimental to the catalyst’s performance
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