35 research outputs found
Prevalence of Symptomatic Heart Failure with Reduced and with Normal Ejection Fraction in an Elderly General Population-The CARLA Study
Background/Objectives: Chronic heart failure (CHF) is one of the most important public health concerns in the industrialized world having increasing incidence and prevalence. Although there are several studies describing the prevalence of heart failure with reduced ejection fraction (HFREF) and heart failure with normal ejection fraction (HFNEF) in selected populations, there are few data regarding the prevalence and the determinants of symptomatic heart failure in the general population. Methods: Cross-sectional data of a population-based German sample (1,779 subjects aged 45-83 years) were analyzed to determine the prevalence and determinants of chronic SHF and HFNEF defined according to the European Society of Cardiology using symptoms, echocardiography and serum NT-proBNP. Prevalence was age-standardized to the German population as of December 31st, 2005. Results: The overall age-standardized prevalence of symptomatic CHF was 7.7% (95%CI 6.0-9.8) for men and 9.0% (95%CI 7.0-11.5) for women. The prevalence of CHF strongly increased with age from 3.0% among 45-54- year-old subjects to 22.0% among 75-83- year-old subjects. Symptomatic HFREF could be shown in 48% (n = 78), symptomatic HFNEF in 52% (n = 85) of subjects with CHF. The age-standardized prevalence of HFREF was 3.8 % (95%CI 2.4-5.8) for women and 4.6 % (95%CI 3.6-6.3) for men. The age-standardized prevalence of HFNEF for women and men was 5.1 % (95%CI 3.8-7.0) and 3.0 % (95%CI 2.1-4.5), respectively. Persons with CHF were more likely to have hypertension (PR = 3.4; 95%CI 1.6-7.3) or to have had a previous myocardial infarction (PR = 2.5, 95%CI 1.8-3.5). Conclusion: The prevalence of symptomatic CHF appears high in this population compared with other studies. While more women were affected by HFNEF than men, more male subjects suffered from HFREF. The high prevalence of symptomatic CHF seems likely to be mainly due to the high prevalence of cardiovascular risk factors in this population
Automated electron diffraction tomography - a new tool for nano crystal structure analysis
Automated electron Diffraction Tomography (ADT) comprises an upcoming method for "ab intio" structure analysis of nano crystals. ADT allows fine sampling of the reciprocal space by sequential collection of electron diffraction patterns while tilting a nano crystal in fixed tilt steps around an arbitrary axis. Electron diffraction is collected in nano diffraction mode (NED) with a semi-parallel beam with a diameter down to 50 nm. For crystal tracking micro-probe STEM imaging is used. Full automation of the acquisition procedure allowed optimisation of the electron dose distribution and therefore analysis of highly beam sensitive samples. Cell parameters, space group and reflection intensities can be determined directly within a reconstructed 3d diffraction volume using a dedicated software package (ADT3D). Intensity data sets extracted from such a volume usually show a high coverage and significantly reduced dynamical effects due to "off-zone" acquisition. The use of this data for "ab initio" structure solution by direct methods implemented in standard programs for X-ray crystallography is demonstrated. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim RI Mugnaioli, Enrico/E-6237-2011; Kolb, Ute/A-2642-201
Structural Characterization of Organics Using Manual and Automated Electron Diffraction
In the last decade the importance of transmission electron microscopic studies has become increasingly important with respect to the characterization of organic materials, ranging from small organic molecules to polymers and biological macromolecules. This review will focus on the use of transmission electron microscope to perform electron crystallography experiments, detailing the approaches in acquiring electron crystallographic data. The traditional selected area approach and the recently developed method of automated diffraction tomography (ADT) will be discussed with special attention paid to the handling of electron beam sensitive organic materials. RI Kolb, Ute/A-2642-2011; Mugnaioli, Enrico/E-6237-201
Back to the Future: Building Up the Case for Exploring Red Blood Cell Morphology in Pulmonary Arterial Hypertension
Structure analysis of titanate nanorods by automated electron diffraction tomography
A hitherto unknown phase of sodium titanate, NaTi3O6(OH)center dot 2H(2)O, was identified as the intermediate species in the synthesis of TiO2 nanorods. This new phase, prepared as nanorods, was investigated by electron diffraction, X-ray powder diffraction, thermogravimetric analysis and high-resolution transmission electron microscopy. The structure was determined ab initio using electron diffraction data collected by the recently developed automated diffraction tomography technique. NaTi3O6(OH)center dot 2H(2)O crystallizes in the monoclinic space group C2/m. Corrugated layers of corner- and edge-sharing distorted TiO6 octahedra are intercalated with Na+ and water of crystallization. The nanorods are typically affected by pervasive defects, such as mutual layer shifts, that produce diffraction streaks along c*. In addition, edge dislocations were observed in HRTEM images. RI Tremel, Wolfgang/D-8125-2011; Andrusenko, Iryna/E-6239-2011; Mugnaioli, Enrico/E-6237-2011; Kolb, Ute/A-2642-201
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Near–atomic-scale observation of grain boundaries in a layer-stacked two-dimensional polymer
Two-dimensional (2D) polymers hold great promise in the rational materials design tailored for next-generation applications. However, little is known about the grain boundaries in 2D polymers, not to mention their formation mechanisms and potential influences on the material’s functionalities. Using aberration-corrected high-resolution transmission electron microscopy, we present a direct observation of the grain boundaries in a layer-stacked 2D polyimine with a resolution of 2.3 Å, shedding light on their formation mechanisms. We found that the polyimine growth followed a “birth-and-spread” mechanism. Antiphase boundaries implemented a self-correction to the missing-linker and missing-node defects, and tilt boundaries were formed via grain coalescence. Notably, we identified grain boundary reconstructions featuring closed rings at tilt boundaries. Quantum mechanical calculations revealed that boundary reconstruction is energetically allowed and can be generalized into different 2D polymer systems. We envisage that these results may open up the opportunity for future investigations on defect-property correlations in 2D polymers