Palaeoecological study of a Weichselian wetland site in the Netherlands suggests a link with Dansgaard-Oeschger climate oscillation

Botanical microfossils, macroremains and oribatid mites of a Weichselian interstadial deposit in the central Netherlands point to a temporary, sub-arctic wetland in a treeless landscape. Radiocarbon dates and OSL dates show an age between ca. 54.6 and 46.6 ka cal BP. The vegetation succession, starting as a peat-forming wetland that developed...

Liposomes with conjugates of a calix[4]arene and a Gd-DOTA derivative on the outside surface: An efficient potential contrast agent for MRI

Paramagnetic liposomes used as contrast agents in magnetic resonance imaging (MRI) often suffer from low efficacies because of slow water diffusion through the membrane. We present an approach to overcome this limitation by incorporation of a calix[4]arene based agent that expresses the chelates towards the bulk water.

Densely packed Gd(III)-chelates with fast water exchange on a calix[4]arene scaffold: A potential MRI contrast agent

A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the corresponding Gd-complex was characterized with respect to its suitability as MRI contrast agent. The compound forms spherical micelles in water with a cmc of 35 mMand a radius of 8.2 nm. The relaxivity of these aggregates is 31.2 s-1 mM-1 at 25ºC and...