Kalkiges Nannoplankton aus dem Unter-Hauterivium bis Unter-Barrêmium der Tongrube (Unter-Kreide, NW-Deutschland)

41 samples which have been collected from the Lower Cretaceous section Moorberg/Sarstedt (Lower Hauterivian-Lower Barremian) have been investigated for calcareous Nannoplankton. About 4500 coccoliths have been measured, most of which are determinated as Biscutum constans, Bidiscus rotatorius, Corollithion geometricum, Cyclagelosphaera margereli, Parhabdolithus asper and Sollasites horticus. These dates are evaluated and partly graphically represented. Within the paleontological part 4 5 species are described and partly illustrated by photos and drawings. 2 new species (Chiastozygus octiformis and Chiastozygus tripes) are introduced, while one genus and one species are emended. Based on 18350 countered specimens the relative quantity of 68 species is shown, 15 of which got stratigraphical signifi- cance for NW-Germany and possible further around. According to the calcareous Nannoplankton the connection of the "boreal realm" and the Tethys should have been interrupted already in the lowermost Upper Hauterivian.

Laser ablation-based one-step generation and bio-functionalization of gold nanoparticles conjugated with aptamers

Background: Bio-conjugated nanoparticles are important analytical tools with emerging biological and medical applications. In this context, in situ conjugation of nanoparticles with biomolecules via laser ablation in an aqueous media is a highly promising one-step method for the production of functional nanoparticles resulting in highly efficient conjugation. Increased yields are required, particularly considering the conjugation of cost-intensive biomolecules like RNA aptamers. Results: Using a DNA aptamer directed against streptavidin, in situ conjugation results in nanoparticles with diameters of approximately 9 nm exhibiting a high aptamer surface density (98 aptamers per nanoparticle) and a maximal conjugation efficiency of 40.3%. We have demonstrated the functionality of the aptamer-conjugated nanoparticles using three independent analytical methods, including an agglomeration-based colorimetric assay, and solid-phase assays proving high aptamer activity. To demonstrate the general applicability of the in situ conjugation of gold nanoparticles with aptamers, we have transferred the method to an RNA aptamer directed against prostate-specific membrane antigen (PSMA). Successful detection of PSMA in human prostate cancer tissue was achieved utilizing tissue microarrays. Conclusions: In comparison to the conventional generation of bio-conjugated gold nanoparticles using chemical synthesis and subsequent bio-functionalization, the laser-ablation-based in situ conjugation is a rapid, one-step production method. Due to high conjugation efficiency and productivity, in situ conjugation can be easily used for high throughput generation of gold nanoparticles conjugated with valuable biomolecules like aptamers.