Prism substructures in the shell of (Linnaeus, 1758), Mollusca - Evidence for a three-dimensional pulsed-growth model.

In the shells of the Pelecypods belonging to the Pinnidae family, the calcareous prismatic units of the outer layer are long-standing references for biomineralization studies. To elucidate how the mechanism of prism formation enables both shell elongation and thickness increase, a top-down structural analysis of these classical "simple prisms" has been carried out, taking advantage of shell sampling on actively mineralizing animals. Particular attention was paid to the morphological and structural patterns of the calcareous units sequentially produced at the margins of the growth lamellae.

Relevance of NH4F in acid digestion before ICP-MS analysis.

In order to implement a simpler, less expensive and more safe sample dissolution procedure, we have substituted the HF-HClO(4) mixture by NH(4)F. By testing three certified reference materials, lichen 336, basalt BE-N, soil 7, it was found that the three-reagents digestion without HF and HClO(4) (HNO(3)+H(2)O(2)+NH(4)F was used) was very effective for the pretreatment of ICP-MS measurement. The comparison was based on the measurement results and their uncertainties.