Flow electrolytic separation of radionuclides for interference suppression in γ-spectrometry.

Background: The direct and accurate measurement of low-level γ-emitters in samples from nuclear facilities is a challenging task due to the presence of high activities of dominant radionuclides. In this case a complex chemical separation is required to remove interfering radionuclides prior to γ-spectrometric analysis. Several radionuclides such as, Ag, Sb, Sn and Te are of relevance for radioanalytical analysis in nuclear facilities.

Radioanalytics - An Indispensable Tool for Radiological and Nuclear Safety.

The exact knowledge on the inventory of a radioactive sample is a precondition to act appropriately in terms of nuclear safety. Radioanalytical methods aimed to determine the radionuclide content of activated material play therefore a central role regarding safe operation of nuclear installations, protection of personnel, inhabitants and environment as well as for the design and construction of new facilities. The article gives an overview on the broad variety of analysis and measurement methods, describes necessary chemical separation procedures and explains the impact for nuclear safety assessment in the field of radioanalytics at the Paul Scherrer Institut Villigen, Switzerland.

No radioactive contamination from the Chernobyl disaster in Hungarian white truffles (Tuber magnatum).

Despite being one of the most expensive gourmet foods, it remains unclear if the iconic White Truffle (Tuber magnatum Pico; hereinafter WT) accumulates radioactivity at harmful levels comparable to other fungal species. Here, we measure the active radiocaesium-137 concentration (Cs) in ten hypogeous WT fruitbodies from southern Hungary, and the soils in which they were growing. All WTs reveal non-significant Cs values, thus providing an 'all clear' for WT hunters in the species' northernmost habitats, where corresponding soil samples occasionally exhibit slight Cs concentrations.

On-chip extrusion of lipid vesicles and tubes through microsized apertures.

In this work we present the formation of micrometre-sized lipid vesicles and tubes with perfectly homogeneous diameter and extraordinary length. The method is a novel approach for unconventional fabrication of soft-matter microstructured devices based on the combination of top-down and bottom-up fabrication processes. Photolithography techniques are applied to fabricate microsized apertures that provide the requirements to form lipid structures with predictable size and to align and guide the vesicles and tubes in microstructured channels.

Gentle cell trapping and release on a microfluidic chip by in situ alginate hydrogel formation.

Microfluidic devices are increasingly used to perform biological experiments on a single-cell basis. However, long-term stability of cell positions is still an issue. A novel biocompatible method for cell entrapment and release on a microchip is presented.

Sequential DNA hybridisation assays by fast micromixing.

The prospects of performing DNA hybridisation assays in a novel sequential scheme are explored in this article. It is based on recording the kinetics of hybridisation on a microfluidic device measuring only 10 by 5 mm. It contains a split channel system for fast mixing and a subsequent meandering channel to observe the evolution of the mixture by optical means.