Surface patterned polymer micro-cantilever arrays for sensing

Microinjection molding was employed to fabricate low-cost polymer cantilever arrays for sensor applications. Cantilevers with micrometer dimensions and aspect ratios as large as 10 were successfully manufactured from polymers, including polypropylene and polyvinylidenfluoride. The cantilevers perform similar to the established silicon cantilevers, with Q-factors in the range of 10–20. Static deflection of gold coated polymer cantilevers was characterized with heat cycling and self-assembled monolayer formation of mercaptohexanols. A hybrid mold concept allows easy modification of the surface topography, enabling customized mechanical properties of individual cantilevers. Combined with functionalization and surface patterning, the cantilever arrays are qualified for biomedical applications

Bild und Begriff. Wie wissenschaftliche Positionen die Bewertung von Theater in der Geschichte prägen

Angesichts der inzwischen geläufigen Terminologie vom prädramatischen, dramatischen und postdramatischen Theater wird diskutiert, wie eine prononciert vorgetragene Auffassung von Theater den Blick und das Verständnis nachhaltig lenkt. Als antiker Anhaltspunkt dient der Anti-Theaterdiskurs Platons. Er soll klären, warum Theater als Kunst zwischen Spätantike und Renaissance aus dem ästhetischen Diskurs verbannt und um welchen Preis es im 17. Jahrhundert wieder aufgenommen wird. Die Postulierung von postdramatischem Theater am Ende des 20. Jahrhunderts, die einen ähnlich starken Einfluss auf die Bewertung von Theater in der Geschichte ausübt, vermag einige Missverständnisse zu beseitigen und schafft andere.

Are ectomycorrhizal fungi alleviating or aggravating nitrogen limitation of tree growth in boreal forests?

•Symbioses between plant roots and mycorrhizal fungi are thought to enhance plant uptake of nutrients through a favourable exchange for photosynthates. Ectomycorrhizal fungi are considered to play this vital role for trees in nitrogen (N)-limited boreal forests. •We followed symbiotic carbon (C)–N exchange in a large-scale boreal pine forest experiment by tracing 13CO2 absorbed through tree photosynthesis and 15N injected into a soil layer in which ectomycorrhizal fungi dominate the microbial community. •We detected little 15N in tree canopies, but high levels in soil microbes and in mycorrhizal root tips, illustrating effective soil N immobilization, especially in late summer, when tree belowground C allocation was high. Additions of N fertilizer to the soil before labelling shifted the incorporation of 15N from soil microbes and root tips to tree foliage. •These results were tested in a model for C–N exchange between trees and mycorrhizal fungi, suggesting that ectomycorrhizal fungi transfer small fractions of absorbed N to trees under N-limited conditions, but larger fractions if more N is available. We suggest that greater allocation of C from trees to ectomycorrhizal fungi increases N retention in soil mycelium, driving boreal forests towards more severe N limitation at low N supply.