123 research outputs found
Zur sprachwissenschaftstheoretischen Diskussion in der Sowjetunion
Theorien und Methoden als an ein bestimmtes Gesellschaftssystem gebunden zu erkennen; oder sind die Voraussetzungen für einen marxistischen Ansatz wirklich nur in einer sozialistischen Gesellschaft gegeben
Zur sprachwissenschaftstheoretischen Diskussion in der Sowjetunion
Theorien und Methoden als an ein bestimmtes Gesellschaftssystem gebunden zu erkennen; oder sind die Voraussetzungen für einen marxistischen Ansatz wirklich nur in einer sozialistischen Gesellschaft gegeben
Constitutive expression of the pre-TCR enables development of mature T cells
Expression and signalling through the pre-TCR and the TCRαβ resemble two critical checkpoints during T cell development. We investigated to which extent a pre-TCR can functionally replace mature TCRα chains during T cell development. For this purpose, transgenic mice were generated expressing the pre-TCRα (pTα) under the transcriptional control of TCRβ regulatory elements. We report here on the interesting finding that constitutive pTα expression allows complete T cell maturation. The pre-TCR complex permits a subset of β-selected thymocytes to mature in the absence of TCRα into peripheral T cells (βT cells) comprising up to 10% of all lymphocytes. Lymphopenia-driven proliferation of these βT cells is similar to that of conventional αβT cells. Furthermore, βT cells proliferated and acquired effector function upon stimulation with allogeneic MH
A Comparative Study of Automatic Localization Algorithms for Spherical Markers within 3D MRI Data
Localization of features and structures in images is an important task in medical image-processing. Characteristic structures and features are used in diagnostics and surgery planning for spatial adjustments of the volumetric data, including image registration or localization of bone-anchors and fiducials. Since this task is highly recurrent, a fast, reliable and automated approach without human interaction and parameter adjustment is of high interest. In this paper we propose and compare four image processing pipelines, including algorithms for automatic detection and localization of spherical features within 3D MRI data. We developed a convolution based method as well as algorithms based on connected-components labeling and analysis and the circular Hough-transform. A blob detection related approach, analyzing the Hessian determinant, was examined. Furthermore, we introduce a novel spherical MRI-marker design. In combination with the proposed algorithms and pipelines, this allows the detection and spatial localization, including the direction, of fiducials and bone-anchors
Occurrence of halogenated flame retardants in commercial seafood species available in European markets
PBDEs (congeners 28, 47, 99, 100, 153, 154, 183, 209), HBCD (α, β, γ), emerging brominated flame retardants (PBEB, HBB and DBDPE), dechloranes (Dec 602, 603, 604, syn- and anti-DP), TBBPA, 2,4,6-TBP and MeO-PBDEs (8 congeners) were analysed in commercial seafood samples from European countries. Levels were similar to literature and above the environmental quality standards (EQS) limit of the Directive 2013/39/EU for PBDEs. Contaminants were found in 90.5% of the seafood samples at n. d.-356 ng/g lw (n. d.-41.1 ng/g ww). DBDPE was not detected and 2,4,6-TBP was detected only in mussels, but at levels comparable to those of PBDEs. Mussel and seabream were the most contaminated species and the Mediterranean Sea (FAO Fishing Area 37) was the most contaminated location. The risk assessment revealed that there was no health risk related to the exposure to brominated flame retardants via seafood consumption. However, a refined risk assessment for BDE-99 is of interest in the future. Moreover, the cooking process concentrated PBDEs and HB
Pharmaceuticals and endocrine disruptors in raw and cooked seafood from European market: Concentrations and human exposure levels
Pharmaceuticals (PhACs) and endocrine disrupting compounds (EDCs) are chemicals of emerging concern that can accumulate in seafood sold in markets. These compounds may represent a risk to consumers through effects on the human reproductive system, metabolic disorders, pathogenesis of breast cancer or development of microbial resistance. Measuring their levels in highly consumed seafood is important to assess the potential risks to human health. Besides, the effect of cooking on contaminant levels is relevant to investigate. Therefore, the objectives of this research were to study the presence and levels of PhACs and EDCs in commercially available seafood in the European Union market, to investigate the effect of cooking on contaminant levels, and to evaluate the dietary exposure of humans to these compounds through seafood consumption. A sampling survey of seafood from 11 European countries was undertaken. Twelve highly consumed seafood types were analysed raw and cooked with 3 analytical methods (65 samples, 195 analysis). PhACs were mostly not detectable or below quantification limits in seafood whereas EDCs were a recurrent group of contaminants quantified in the majority of the samples. Besides, cooking by steaming significantly increased their levels in seafood from 2 to 46-fold increase. Based on occurrence and levels, bisphenol A, methylparaben and triclosan were selected for performing a human exposure assessment and health risk characterisation through seafood consumption. The results indicate that the Spanish population has the highest exposure to the selected EDCs through seafood consumption, although the exposure via seafood remained below the current toxicological reference values.info:eu-repo/semantics/acceptedVersio
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