Lanthano phosphomolybdate-decorated silica nanoparticles: novel hybrid materials with photochromic properties.

Novel photochromic hybrid nanomaterials were prepared through the immobilization of the lacunary Keggin-type phosphomolybdate (TBA4H3[PMo11O39]·xH2O, denoted as PMo11) and sandwich-type lanthano phosphomolybdates (K11[Ln(III)(PMo11O39)2]·xH2O, denoted as Ln(PMo11)2, where Ln(III) = Sm, Eu, Gd, Tb and Dy) onto positively-charged functionalized silica nanoparticles. The functionalized silica nanoparticles were prepared by a one-step co-condensation route between tetraethyl orthosilicate and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, presenting an average particle size of 95 ± 26 nm, a spherical morphology and a pore diameter of 13.7 nm. All characterization techniques proved the successful immobilization of the phosphomolybdates. The photochromic properties of the resulting hybrid nanomaterials in the solid state were evaluated by UV-Vis spectroscopy and colorimetry. All materials revealed promising photochromic properties under UV irradiation (λ = 254 nm). The lacunary phosphomolybdate anchored onto the silica nanoparticles, C18-SiO2@PMo11, showed the best photoswitching properties, with the color changing from green to dark-blue (ΔE* = 26.8). Among the Ln(PMo11)2-based hybrid nanomaterials, those containing higher Mo loadings--Eu(III)- and Tb(III)-based samples--presented more significant color changes from green to dark-blue (ΔE* = 18.8-18.9). These results revealed that the optical properties of the as-prepared hybrid nanomaterials did not depend directly on the type of Ln(III) cation, but only on the amount of Mo, which was the target element responsible for the photochromic behavior.

Condrosarcoma laríngeo. A propósito de un caso / Larynx chondrosarcoma. A case report

El condrosarcoma laríngeo es un raro tumor no epitelialde lento crecimiento derivado del sistema cartilaginoso de la laringe. Aunque es el tumor mesenquimatoso más frecuente en la laringe 1 tan sólo representa entre un 0,5 yun 1% de los procesos neoplásicos de la laringe 2,3. Elcricoides es el lugar más común de aparición en la laringe 4. Debido a su baja frecuencia, en la literatura tan sólo existen entre 250 y 300 publicaciones sobre él 1,5-8. Su pronóstico está muy relacionado con su histología y su tratamiento quirúrgico precisa un seguimiento y control estrechos tras la cirugía. Presentamos el caso de un condrosarcoma laríngeo de localización subglótica, de lenta evolución que cursó con disfonía y disnea y que fue tratado mediante cirugía

Larynx chondrosarcoma is a rare non epithelial slow growing tumor derivated from the cartilaginous system of the larynx. Although its the most common mesenchimal tumor in larinx only represents between a 0.5 and a 1 %of all the larinx tumors. Due to its low frecuency there are only between 250 and 300 cases reported in the literature about it. Its prognostic is related to it´s histopathology and its surgical treatment needs a close follow up and control after surgery for the detection of recurrences and metastases. We present the case of a larynx chondrosarcoma of subglotic localitation, slow growing that cursed with hoarness and dysnea and was treated by surgery