Atomic fluorescence mapping of optical field intensity profiles issuing from nanostructured slits, milled into subwavelength metallic layers

In this work, we report on the fabrication and characteristics of light-emitting diodes based on p-GaN/i-ZnO/n-ZnO heterojunction. A 30 nm i-ZnO layer was grown on p-GaN by rf reactive magnetron sputtering, then a n-ZnO was deposited by the electron beam evaporation technique. The current-voltage characteristic of the obtained p-i-n heterojunction exhibited a diode-like rectifying behavior. Because the electrons from n-ZnO and the holes from p-GaN could be injected into a i-ZnO layer with a relatively low carrier concentration and mobility, the radiative recombination was mainly confined in i-ZnO region. As a result, an ultraviolet electro-emission at 3.21 eV, related to ZnO exciton recombination, was observed in a room-temperature electroluminescence spectrum of p-i-n heterojunction under forward bias.     

Physicochemical characterization of the endotoxins from Coxiella burnetii strain Priscilla in relation to their bioactivities

Background  

Coxiella burnetiiis the etiological agent of Q fever found worldwide. The microorganism has like other Gram-negative bacteria a lipopolysaccharide (LPS, endotoxin) in its outer membrane, which is important for the pathogenicity of the bacteria. In order to understand the biological activity of LPS, a detailed physico-chemical analysis of LPS is of utmost importace.