First experience with single-source, dual-energy CCTA for monochromatic stent imaging

Aims Single-source, dual-energy coronary computed tomography angiography (CCTA) with monochromatic image reconstruction allows significant noise reduction. The aim of the study was to evaluate the impact of monochromatic CCTA image reconstruction on coronary stent imaging, as the latter is known to be affected by artefacts from highly attenuating strut material resulting in artificial luminal narrowing. Methods and results Twenty-one patients with 62 stents underwent invasive coronary angiography and single-source, dual-energy CCTA after stent implantation. Standard polychromatic images as well as eight monochromatic series (50, 60, 70, 80, 90, 100, 120, and 140 keV) were reconstructed for each CCTA. Signal and noise were measured within the stent lumen and in the aortic root. Mean in-stent luminal diameter was assessed in all CCTA reconstructions and compared with quantitative invasive coronary angiography (QCA). Luminal attenuation was higher in the stent than in the aortic root throughout all monochromatic reconstructions (P < 0.001). An increase in monochromatic energy was associated with a decrease in luminal attenuation values (P < 0.001). The mean in-stent luminal diameter underestimation by monochromatic CCTA compared with QCA was 90% at low monochromatic energy (50 keV) and improved to 37% at high monochromatic (140 keV) reconstruction while stent diameter was underestimated by 39% with standard CCTA. Conclusion Monochromatic CCTA can be used reliably in patients with coronary stents. However, reconstructions with energies below 80 keV are not recommended as the blooming artefacts are most pronounced at such low energies, resulting in up to 90% stent diameter underestimatio

Glasses for the preparation of gradient index lenses in the Na2O-Al2O3-B2O3-SiO2 system - hydrolytic durability, thermal and optical properties

Glasses in the system Na2O-Al2O3-B2O3-SiO2 were melted from the raw materials and studied with respect to their chemical durability, their crystal growth velocities, their refractive index and dispersion, their glass transition temperature and their thermal expansion coeffieient. With inereasing Na2O concentration, the crystal growth velocity increases and the chemical durability decreases. Equimolar subtitution of B2O3 for SiO2 results in a decrease in both the chemical durability and in crystal growth velocities. Equimolar subtitution of AI2O3 for SiO2 leads to increasing chemical durability and decreasing crystal growth velocities. Optimum glass compositions to produce gradient index lenses should possess B2O3 concentrations of around 12.5 to 15 mor% and molar AI2O3 concentrations some percent larger than the Na2O concentration. In these glasses, nonbridging oxygen does not occur

The localisation of acids, sugars, potassium and calcium in developing grape berries

Grape berries (Vitis vinifera cv. Chardonnay) were divided into four concentric zones in order to follow the developmental changes in the concentrations of malate, tartrate, glucose, fructose, potassium and calcium within the skin and the fruit flesh. Green berries showed a definite malate gradient, increasing in concentration from the skin towards the seeds; tartaric acid, on the other hand, was highest in concentration at the periphery and lowest in the berry center. With progressing maturity, the ratio between the tartrate concentration in the skin and the corresponding values in the berry core decreased, whereas the reverse was true for malate. In the ripe berry an acid gradient could also be found in the axial direction, decreasing from the pedicel towards the stylar scar. Before the onset of ripening, the highest glucose and fructose concentrations were observed in the skin and the berry center. The accumulation of these sugars in the pulp began without any apparent lag phase at a rate of about 2 mg/ berry · d. After veraison, the highest concentrations were found in the fruit core and the tissue below the peripheral vascular bundles. Both potassium and calcium were mainly localized near the peripheral and central vascular bundles. The potassium content increased during the entire period of berry development at a constant rate of 0.04 mg/berry · d, whereas calcium accumulation stopped about 30 d after anthesis. At this time, the calcium content was approximately 0.1 mg/berry

Structural studies of glycoprotein sorting and processing complexes in the early secretory pathway

The secretory pathway of a eukaryotic cell exerts a stringently regulated quality control system for the correct folding and transport of newly synthesised proteins and their subsequent transfer to their final destinations. While this pathway has been mostly studied in yeast, it has become increasingly clear that aberrations in its function are the main causes of a range of human disorders, and we are still in the process of gathering knowledge of the underlying molecular structures and mechanisms of the disease-causing agents in order to fully understand their impact. ERGIC-53, Erv41p and Ktr4p are all membrane anchored proteins involved in the transport or processing of glycoproteins, and form the main focus of this thesis. We have used X-ray crystallography and small-angle X-ray scattering, together with complementary biophysical and biochemical methods, to provide detailed descriptions of these proteins. The human glycoprotein transporter ERGIC-53 is responsible for the export of specific cargo proteins, which it binds in the endoplasmic reticulum (ER) and releases in the ER-Golgi intermediate compartment whilst cycling between the two organelles. Association of ERGIC-53 with the co-transporter MCFD2 is required for the transport of a subset of cargo proteins. ERGIC-53 is only able exert its function when present within the cell as a hexamer, but the details regulating its oligomeric state are still debated, and the structure of the hexameric protein remains unknown. We show that the oligomerisation of ERGIC-53 is independent of disulfide-bond formation and, based on small-angle X-ray scattering experiments, propose two alternative shapes describing the structure of the soluble lumenal part of the protein in its hexameric state. Erv41p is a glycoprotein transporter found in complex with its homologue Erv46p in yeast, and, similarly to ERGIC-53, the complex governs the export of cargo proteins from the ER to the Golgi apparatus, as well as the retrieval of escaped proteins back towards the ER. We have determined the structure of the soluble domain of Erv41p by X-ray crystallography, and show that the protein is comprised of a twisted β-sandwich. With almost the entirety of the concave face of Erv41p being negatively charged, this could be the site of interaction with its cargo or another interaction partner. One cargo protein that has recently been revealed to be transported by the Erv41p/Erv46p- complex is Ktr4p, a protein localised to the Golgi apparatus. Ktr4p is a member of a protein family associated with glycoprotein processing. The structures of the Ktr4p apo-protein and its complex with GDP were determined by X-ray crystallography and show that the protein is comprised of a central β-sheet surrounded by α-helices, and that it belongs to the GT-A fold class of glycosyltransferases In addition, we have biochemically characterised the protein's function and show that it indeed possesses mannosyltransferase activity

Intracardiac bone cement embolism resulting in ventricular perforation: an unusual cause of sudden chest pain.

Leakage of bone cement is a known complication after percutaneous kyphoplasty. In rare cases, bone cement can reach the venous system and cause life-threatening embolism. We present the case of a 73-year-old male, who was admitted to our hospital with new-onset chest pain and dyspnoea. He had a history of percutaneous kyphoplasty. Multimodal imaging showed intracardiac cement embolism in the right ventricle with penetration of the interventricular septum and perforation of the apex. The bone cement was successfully removed during open cardiac surgery

Exploring the business model canvas of mazars group: A comprehensive analysis

This journal article explores the complex business model of Mazars Group, a global professional service provider specializing in audit, tax, and advisory services. Through the lens of the Business Model Canvas (BMC), critical elements shaping Mazars' operations, including key partnerships, activities, resources, value propositions, customer relationships, channels, customer segments, cost structure, and revenue streams, are thoroughly analyzed. The study employs a qualitative approach, combining insights from interviews with a senior associate and web searches to understand Mazars' business model comprehensively. Mazars' commitment to service quality is emphasized, acknowledging the evolving landscape of technology and competition. The company's competitive advantage derives from critical factors such as strategic partnerships with law firms, consulting firms, and technology providers, extensive global reach, diverse services, and a personalized client approach. The marketing strategy is evaluated, with a recommendation to incorporate Google Ads to enhance visibility and capitalize on online consumer trends. The article highlights Mazars' success in delivering high-quality, integrated services to diverse client segments, ranging from startups to large enterprises and non-profit organizations. The firm's cost structure, revenue diversification, and global presence contribute to its resilience in the professional services industry. Mazars Group's enduring success serves as a valuable case study for professionals, academics, and businesses navigating the complexities of the global economy

Anwendung von Causal-Discovery-Algorithmen zur Root-Cause-Analyse in der Fahrzeugmontage

Root Cause Analysis (RCA) is a quality management method that aims to systematically investigate and identify the cause-and-effect relationships of problems and their underlying causes. Traditional methods are based on the analysis of problems by subject matter experts. In modern production processes, large amounts of data are collected. For this reason, increasingly computer-aided and data-driven methods are used for RCA. One of these methods are Causal Discovery Algorithms (CDA). This publication demonstrates the application of CDA on data from the assembly of a leading automotive manufacturer. The algorithms used learn the causal structure between the characteristics of the manufactured vehicles, the ergonomics and the temporal scope of the involved assembly processes, and quality-relevant product features based on representative data. This publication compares various CDAs in terms of their suitability in the context of quality management. For this purpose, the causal structures learned by the algorithms as well as their runtime are compared. This publication provides a contribution to quality management and demonstrates how CDAs can be used for RCA in assembly processes.in German languag

The efficacy of aerosol–cloud radiative perturbations from near-surface emissions in deep open-cell stratocumuli

Aerosol–cloud radiative effects are determined and quantified in simulations of deep open-cell stratocumuli observed during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) campaign off the west coast of Chile. The cloud deck forms in a boundary layer 1.5&thinsp;km deep, with cell sizes reaching 50&thinsp;km in diameter. Global databases of ship tracks suggest that these linear structures are seldom found in boundary layers this deep. Here, we quantify the changes in cloud radiative properties to a continuous aerosol point source moving along a fixed emission line releasing 1017 particles per second. We show that a spatially coherent cloud perturbation is not evident along the emission line. Yet our model simulates an increase in domain-mean all-sky albedo of 0.05, corresponding to a diurnally averaged cloud radiative effect of 20&thinsp;W m−2, given the annual mean solar insolation at the VOCALS-REx site. Therefore, marked changes in cloud radiative properties in precipitating deep open cells may be driven by anthropogenic near-surface aerosol perturbations, such as those generated by ships. Furthermore, we demonstrate that these changes in cloud radiative properties are masked by the naturally occurring variability within the organised cloud field. A clear detection and attribution of cloud radiative effects to a perturbation in aerosol concentrations becomes possible when sub-filtering of the cloud field is applied, using the spatio-temporal distribution of the aerosol perturbation. Therefore, this work has implications for the detection and attribution of effective cloud radiative forcing in marine stratocumuli, which constitutes one of the major physical uncertainties within the climate system. Our results suggest that ships may sometimes have a substantial radiative effect on marine clouds and albedo, even when ship tracks are not readily visible.</p

Stable Longitudinal Quality of Life in the SERVE Trial Among Adults With Transposition of the Great Arteries and a Systemic Right Ventricle.

Adults with a transposition anatomy and a systemic right ventricle (RV) face long-term complications that may impact their quality of life (QoL). Few data are available regarding the QoL in this patient group and its evolution over time. This study was performed in the SERVE trial's (identifier: NCT03049540) prospective cohort of patients (n = 100) with congenitally corrected transposition of the great arteries (TGA) or dextro-TGA after the atrial switch procedure and a longitudinal follow-up of 3 years. We aimed to describe the longitudinal QoL levels and their predictors. QoL was assessed using the Linear Analog Scale. QoL parameters were collected at baseline, after 12 months, and after 36 months, together with clinical parameters and a questionnaire assessing general self-efficacy (GSE). The mean QoL on the Linear Analog Scale was 79.1 ± 13.6 at baseline, 75.5 ± 14.8 at 1 year, and 79.2 ± 13.6 at 3-year follow-up (P = 0.900). No significant differences in QoL were observed between congenitally corrected TGA or dextro-TGA patients. Cardiopulmonary exercise testing maximum work rate and maximum oxygen uptake, New York Heart Association class, end-diastolic RV volumes, N-terminal pro-B-type natriuretic peptide concentration, and GSE showed significant correlations with QoL levels. Multivariable regression analysis identified GSE value and New York Heart Association class (r &lt;sup&gt;2&lt;/sup&gt; = 0.283, P &lt; 0.001) as independent predictors of QoL at baseline. Patients with a systemic RV reported a stable good QoL during 3 years of follow-up. Exercise capacity and self-efficacy were the only independent predictors of QoL. NCT03049540