Suchergebnisse

Abstract
High aspect ratio materials (HARMs) like multi-walled carbon nanotubes (MWCNTs) show material properties that enable innovative applications but also raise concerns about harmful effects to humans due to their asbestos-like pathogenicity. The fibre-pathological paradigm was established for asbestos and other HARM, linking fibre-specific adverse effects to certain material properties such as fibre length, respirability and bio-persistence. A new risk banding scheme for such hazard- and exposure-related properties is introduced. For each relevant property, we defined descriptors and developed/validated methods for their measurement. Based on results from studies conducted in the project or obtained from literature, we defined quantitative band limits. While the fibre-pathological paradigm acted as a starting point, observations of in vitro effect of nanofibers motivated us to incorporate additional properties. Studying macrophage-fibre interactions led us to highlight the importance of the flexural rigidity of fibres for their uptake by macrophages. Also, the bundling of thin constituent fibres was recognized as a mechanism possibly generating less flexible and, therefore, more harmful inhalable particles with high aspect ratio from harmless precursors. Transformation dynamics of fibres in fluids like the phagolysosomal medium were investigated as well to gain a better understanding about fibre bio-durability. Overall, the risk for humans exposed to HARMs is described by the risk banding scheme in which property bands relevant for the hazard potential were juxtaposed to the respective exposure potential. We present results for a selection of HARMs including multiple MWCNTs with varying properties, TiO2 fibres, SiC whiskers, as well as silver and copper nanowires.

zusammenfassungDas DNVF Memorandum – Ziele und Methoden bewegungsbezogener Versorgungsforschung
fasst das erste Mal das stark interdisziplinäre und interprofessionelle Feld der
Bewegungsversorgung im deutschen Gesundheitssystem zusammen. Neben einer
begrifflichen Einordnung und Definition zentraler Maßnahmen und Konzepte der
Bewegungsversorgungsforschung werden bestehende Forschungslücken und
Forschungsbedarfe herausgearbeitet und Methoden zur Weiterentwicklung des noch
recht jungen Forschungsgebiets beschrieben. Ein besonderer Fokus liegt hierbei
auf der Darstellung relevanter Zielparameter und deren standardisierte Erfassung
mittels etablierter und valider Messinstrumente. Ziel des Memorandums ist es,
ein einheitliches Verständnis für den komplexen Gegenstand der
Bewegungsförderung und Bewegungstherapie im Kontext der Gesundheitsversorgung zu
schaffen, neue Forschungsinitiativen anzustoßen und die bestehende gute Evidenz
zur Wirksamkeit von körperlicher Aktivität und körperlichem Training stärker in
die Gesundheitsversorgung zu integrieren.

We report on the properties of pre-main-sequence objects in the Taurus molecular clouds as observed in seven mid-and far-infrared bands with the Spitzer Space Telescope. There are 215 previously identified members of the Taurus star-forming region in our similar to 44 deg(2) map; these members exhibit a range of Spitzer colors that we take to define young stars still surrounded by circumstellar dust (noting that similar to 20% of the bona fide Taurus members exhibit no detectable dust excesses). We looked for new objects in the survey field with similar Spitzer properties, aided by extensive optical, X-ray, and ultraviolet imaging, and found 148 new candidate members of Taurus. We have obtained follow-up spectroscopy for about half the candidate sample, thus far confirming 34 new members, three probable new members, and 10 possible new members, an increase of 15%-20% in Taurus members. Of the objects for which we have spectroscopy, seven are now confirmed extragalactic objects, and one is a background Be star. The remaining 93 candidate objects await additional analysis and/or data to be confirmed or rejected as Taurus members. Most of the new members are Class II M stars and are located along the same cloud filaments as the previously identified Taurus members. Among non-members with Spitzer colors similar to young, dusty stars are evolved Be stars, planetary nebulae, carbon stars, galaxies, and active galactic nuclei. ; NASA ; JPL/Caltech ; National Science Foundation ; U.S. Government NAG W-2166 ; ESA ; Swiss National Science Foundation PP002-110504 ; Astronomy