Dysprosium Doped Zinc Oxide for NO2 Gas Sensing.

Pure and dysprosium-loaded ZnO films were grown by radio-frequency magnetron sputtering. The films were characterized using a wide variety of morphological, compositional, optical, and electrical techniques. The crystalline structure, surface homogeneity, and bandgap energies were studied in detail for the developed nanocomposites. The properties of pure and dysprosium-doped ZnO thin films were investigated to detect nitrogen dioxide (NO2) at the ppb range. In particular, ZnO sensors doped with rare-earth materials have been demonstrated as a feasible strategy to improve the sensitivity in comparison to their pure ZnO counterparts. In addition, the sensing performance was studied and discussed under dry and humid environments, revealing noteworthy stability and reliability under different experimental conditions. In this perspective, additional gaseous compounds such as ammonia and ethanol were measured, resulting in extremely low sensing responses. Therefore, the gas-sensing mechanisms were discussed in detail to better understand the NO2 selectivity given by the Dy-doped ZnO layer.

[Ophthalmic manifestations of lipoid proteinosis]. / Manifestations ophtalmologiques de la hyalinose cutanéo-muqueuse.

INTRODUCTION: Lipoid proteinosis (LP), also known as hyalinosis (or lipoidosis) cutis et mucosae or Urbach-Wiethe disease, is a rare autosomal recessive disorder. It is associated with deposits of protein-lipid complexes in various tissues including the skin and mucous membranes. Ophthalmologic manifestations are frequent and can affect visual prognosis. CASE: This 28-year-old patient presented vesiculobullous lesions of the face that developed into varioloid scars associated with hoarseness. Ophthalmologic examination revealed unilateral lesions including hyaline deposits on the palpebral margins, iris, and trabecular zone, complicated by uveitis, cataract, and glaucoma, which caused the functional loss of the left eye. Histological examination of a cutaneous biopsy confirmed the diagnosis. DISCUSSION: Involvement of the eyelids is characteristic, and moniliform blepharosis is pathognomonic and frequent. This case featured a rare intraocular form (uveitis). Deposits may be found on the conjunctiva, cornea, trabecula and Bruch membrane. Conjunctival or cutaneous biopsy confirms the diagnosis. Available treatment is quite limited.