31 research outputs found
On the commutability of homogenization and linearization in finite elasticity
We study non-convex elastic energy functionals associated to (spatially)
periodic, frame indifferent energy densities with a single non-degenerate
energy well at SO(n). Under the assumption that the energy density admits a
quadratic Taylor expansion at identity, we prove that the Gamma-limits
associated to homogenization and linearization commute. Moreover, we show that
the homogenized energy density, which is determined by a multi-cell
homogenization formula, has a quadratic Taylor expansion with a quadratic term
that is given by the homogenization of the quadratic term associated to the
linearization of the initial energy density
Cardiac biomarkers of prognostic importance in chronic obstructive pulmonary disease
Background: Ischemic heart disease is common in COPD and associated with worse prognosis. This study aimed to investigate the presence and prognostic impact of biomarkers of myocardial injury and ischemia among individuals with COPD and normal lung function, respectively. Methods: In 2002–04, all individuals with airway obstruction (FEV1/VC < 0.70, n = 993) were identified from population-based cohorts, together with age and sex-matched non-obstructive referents. At re-examination in 2005, spirometry, Minnesota-coded ECG and analyses of high-sensitivity cardiac troponin I (hs-cTnI) were performed in individuals with COPD (n = 601) and those with normal lung function (n = 755). Deaths were recorded until December 31st, 2010. Results: Hs-cTnI concentrations were above the risk stratification threshold of ≥5 ng/L in 31.1 and 24.9% of those with COPD and normal lung function, respectively. Ischemic ECG abnormalities were present in 14.8 and 13.4%, while 7.7 and 6.6% had both elevated hs-cTnI concentrations and ischemic ECG abnormalities. The 5-year cumulative mortality was higher in those with COPD than those with normal lung function (13.6% vs. 7.7%, p < 0.001). Among individuals with COPD, elevated hs-cTnI both independently and in combination with ischemic ECG abnormalities were associated with an increased risk for death (adjusted hazard ratio [HR]; 95% confidence interval [CI] 2.72; 1.46–5.07 and 4.54; 2.25–9.13, respectively). Similar associations were observed also among individuals with COPD without reported ischemic heart disease. Conclusions: In this study, elevated hs-cTnI concentrations in combination with myocardial ischemia on the electrocardiogram were associated with a more than four-fold increased risk for death in a population-based COPD-cohort, independent of disease severity
Comparison of target enrichment strategies for ancient pathogen DNA
In ancient DNA research, the degraded nature of the samples generally results in poor yields of highly fragmented DNA; targeted DNA enrichment is thus required to maximize research outcomes. The three commonly used methods ? array-based hybridization capture and in-solution capture using either RNA or DNA baits ? have different characteristics that may influence the capture efficiency, specificity and reproducibility. Here we compare their performance in enriching pathogen DNA of Mycobacterium leprae and Treponema pallidum from 11 ancient and 19 modern samples. We find that in-solution approaches are the most effective method in ancient and modern samples of both pathogens and that RNA baits usually perform better than DNA baits
An overview of recent developments in the analytical detection of new psychoactive substances (NPSs)
New psychoactive substances (NPSs), sometimes referred to as “legal highs” in more colloquial environments/
the media, are a class of compounds that have been recently made available for abuse (not
necessarily recently discovered) which provide similar effects to the traditional well studied illegal drugs
but are not always controlled under existing local, regional or international drug legislation. Following an
unprecedented increase in the number of NPSs in the last 5 years (with 101 substances discovered for the
first time in 2014 alone) its, occasionally fatal, consequences have been extensively reported in the media.
Such NPSs are typically marketed as ‘not for human consumption’ and are instead labelled and sold as
plant food, bath salts as well as a whole host of other equally nondescript aliases in order to bypass legislative
controls. NPSs are a new multi-disciplinary research field with the main emphasis in terms of forensic
identification due to their adverse health effects, which can range from minimal to life threatening and
even fatalities. In this mini-review we overview this recent emerging research area of NPSs and the
analytical approaches reported to provide detection strategies as well as detailing recent reports towards
providing point-of-care/in-the-field NPS (“legal high”) sensors
Elevated high-sensitivity cardiac troponin T is associated with increased mortality after acute exacerbation of chronic obstructive pulmonary disease
Zum Stand der virtuellen Werkstoffentwicklung: Vom Halbzeug zum Crash
Due to environmental aspects in automotive industry weight reduction of body parts is one of the main challenges. Increase of safety and comfort requirements accompanied by decrease of weight leads to the necessity of complex construction and application of innovative steel in car part production. The implementation of innovative steel grades is delayed in market introduction due to difficulties in production and processing of these steels. To overcome this problem, Salzgitter Mannesmann Research GmbH, Daimler AG, Kirchhoff automotive GmbH, DYNAmore GmbH, Fraunhofer-Institute for Mechanics of Materials IWM and Max-Planck Institute for Iron Research GmbH started a joint research project which is founded by the German Federal Ministry of Education in 2006. The goal of this project ist the acceleration of the development and market introduction of new steel grades. Within this project, a simulation strategy for modelling the process chain of dual phase steels from hot rolled strip to the behaviour of components under crash conditions was developed. These tools permit on the mechanical properties on macroscopic level and to transfer the relevant data from step to step along th whole process chain. Different length scales are applied for an adequate data structure of each simulation model. For example, numerical homogenization of the microstructure properties to provide a macroscopic material description is carried out by a so-called "Virtual lab". The developed process chain simulation, allows steel manufacturers a fast and purposeful modification of the process parameters and thus of material properties. Consequently, application of the process chain simulation enables an enormous time and cost reduction during the introduction of new steels automotive market
The production of a condition resembling myasthenia gravis or familial periodic paralysis in the rat
2000-year-old pathogen genomes reconstructed from metagenomic analysis of Egyptian mummified individuals
BACKGROUND: Recent advances in sequencing have facilitated large-scale analyses of the metagenomic composition of different samples, including the environmental microbiome of air, water, and soil, as well as the microbiome of living humans and other animals. Analyses of the microbiome of ancient human samples may provide insights into human health and disease, as well as pathogen evolution, but the field is still in its very early stages and considered highly challenging. - RESULTS: The metagenomic and pathogen content of Egyptian mummified individuals from different time periods was investigated via genetic analysis of the microbial composition of various tissues. The analysis of the dental calculus’ microbiome identified Red Complex bacteria, which are correlated with periodontal diseases. From bone and soft tissue, genomes of two ancient pathogens, a 2200-year-old Mycobacterium leprae strain and a 2000-year-old human hepatitis B virus, were successfully reconstructed. - CONCLUSIONS: The results show the reliability of metagenomic studies on Egyptian mummified individuals and the potential to use them as a source for the extraction of ancient pathogen DNA.Background Results - Sample information and dating - General metagenomic assessment - Mycobacterium leprae (individual Abusir1630) - Hepatitis B virus (individual Abusir1543) - Oral microbiome assessment Discussion Conclusions Methods - Sample extraction and radiocarbon dating - Sample extraction and library preparation - Metagenomic screening - Authentication of ancient DNA - Content of endogenous DNA (SourceTracker2) - Data processing of sample Abusir1630b (M. leprae) -- Read processing, mapping, and variant calling -- SNP typing -- Anthropological analysis -- Phylogeny -- Beast analysis -- Temporal signal - Data processing individual Abusir1543 (hepatitis B virus) -- Read processing, mapping, and variant calling -- Phylogeny -- Recombination analysis -- Beast analysis -- Temporal signa