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Wurtzite single crystal GaN nanocolumns were grown by plasma-assisted molecular beam epitaxy on bare Si(001) substrates. Nanocolumns with diameters in the range of 20–40nm have no traces of extended defects and they grow aligned along the [0001] direction. Photoluminescence measurements in nanocolumns evidence a very high crystal quality in terms of intense and narrow excitonic emissions. Raman scattering data show that the nanocolumns are strain-free. These results open the way to an efficient integration of optoelectronic devices with the complementary metal oxide semiconductor technology.

A pharmacological study of hydrosoluble and liposoluble extracts of the marine microalgae Chlorella stigmatophora and Phaeodactylum tricornutum indicated that hydrosoluble components of both species show significant antiinflammatory, analgesic and free radical scavenging activity. These activities were not detected in the liposoluble fractions.