Design of metallic nanoparticle gratings for filtering properties in the visible spectrum.

Plasmonic resonances in metallic nanoparticles are exploited to create efficient optical filtering functions. A finite element method is used to model metallic nanoparticle gratings. The accuracy of this method is shown by comparing numerical results with measurements on a two-dimensional grating of gold nanocylinders with an elliptic cross section. A parametric analysis is then performed in order to design efficient filters with polarization dependent properties together with high transparency over the visible range. The behavior of nanoparticle gratings is also modeled using the Maxwell-Garnett homogenization theory and analyzed by comparison with the diffraction of a single nanoparticle. The proposed structures are intended to be included in optical systems that could find innovative applications.

[Striated and delayed nephrography]. / Néphrographie striée et prolongée.

About a case of striated and delayed nephrogram seen on a diabetic child, authors come back to the different etiologies. Among them, the tubular precipitation of Tamm-Horsfall protein seems to be given like on the right possibilities. Whatever is its etiology, the mechanism of striated appearance is always the same, being founded on the radiated disposal of the collecting ducts and on a tubular stasis beeing with iodine concentration.

[Multilocular cystadenoma of the pancreas. An uncommon tumor in the child]. / Cystadénome multiloculaire du pancréas. Une tumeur exceptionnelle chez l'enfant.

A 9-month-old infant presented with a multilocular pancreatic cystadenoma. Pathological features of this extremely rare lesion in children are outlined and the relevant literature reviewed. Diagnostic methods are analyzed, and emphasis placed on the difficulty of diagnosis of non-renal multicystic abdominal masses by ultrasound imaging in children.