Biocompatible Probes Based on Rare-Earth Doped Strontium Aluminates with Long-Lasting Phosphorescent Properties for In Vitro Optical IMAGING.

In recent decades, the demand for biomedical imaging tools has grown very rapidly as a key feature for biomedical research and diagnostic applications. Particularly, fluorescence imaging has gained increased attention as a non-invasive, inexpensive technique that allows real-time imaging. However, tissue auto-fluorescence under external illumination, together with a weak tissue penetration of low wavelength excitation light, largely restricts the application of the technique. Accordingly, new types of fluorescent labels are currently being investigated and, in this search, phosphorescent nanoparticles promise great potential, as they combine the interesting size-dependent properties of nanoscale materials with a long-lasting phosphorescence-type emission that allows optical imaging well after excitation (so avoiding autofluorescence). In this work, core-shell structures consisting of SrAlO:Eu,Dy luminescent cores encapsulated within a biocompatible silica shell were prepared, showing a green persistent phosphorescence with an afterglow time of more than 1000 s. A high-energy ball milling procedure was used to reduce the size of the starting phosphors to a size suitable for cellular uptake, while the silica coating was produced by a reverse micelle methodology that eventually allows the excitation and emission light to pass efficiently through the shell. Confocal fluorescence microscopy using HeLa cancer cells confirmed the potential of the all-ceramic composites produced as feasible labels for in vitro optical imaging.

Elucidating a particulate matter deposition episode by combining scanning electron microscopy and X-ray fluorescence spectrometry.

Multielemental composition and morphology of particulate matter samples were examined to detect the presence of two potential responsible pollutant emitters at four sites impacted during a pollution episode in the City of Campana, Argentina. Coke and smoke black are the main constituents associated to the industrial plants that were considered, a priori, as responsible pollutant emitters. Wavelength dispersive X-ray fluorescence (WDXRF) was employed for the analysis of metals in samples coming from both, suspected sources and four sites. On the basis of multielemental composition profiles, a screening analysis was undertaken for exploring similarities among sources and sample sites adopting the average concentration profile of the crustal rock as soil surrogate. Particle morphology was studied by scanning electron microscopy (SEM) in source samples and in those environmental samples selected through the screening analysis. Two types of collected samples were analyzed: 1) those with composition profiles closer to the potential sources and 2) those closer to the cluster rock. This strategy was adequate to identify the responsible source of the contamination episode.

Identificación de fuentes de emisión por microscopía electrónica y difracción por rayos X

Estudio de identificación de fuentes de emisión de material particulado, tomando como base dos muestras patrón y analizando una muestra tomada en aire ambiente. Se analizaron mediante difracción de rayos X (DRX), microscopía electrónica de barrido (MEB), y espectrometría de energía dispersiva de rayos X (EDX)

Enfisema lobar congénito: reporte de nueve casos y revisión de la literatura / Congenital lobar emphysema: report of nine cases and review of the literature

El enfisema lobar congénito (ELC), es una causa importante de insuficiencia respiratoria en los primeros meses de la vida. Los datos clínicos más importantes son taquipnea, cianosis intermitente y asimetría torácica debido al abombamiento del hemitórax afectado. La radiografía de tórax revela un área hiperinsuflada, los lóbulos adyacentes están comprimidos, el contenido mediastinal puede estar desplazado y el pulmón contralateral parcialmente colapsado. La información sobre procedimientos diagnósticos y el tratamiento del ELC en la edad pediátrica es limitado. Presentamos nueve casos con diagnóstico de ELC vistos durante los últimos 10 años en el Instituto Nacional de Enfermedades Respiratorias.

Fístula arteriovenosa pulmonar: informe de un caso / pulmonary arteriovenous fistula: a case report

La fístula arteriovenosa pulmonar es una malformación congénita de la vasculatura pulmonar con persistencia de una o más comunicaciones entre los capilares pulmonares; el efecto fisiopatológico es consecuencia de la falta de oxigenación por paso directo de la sangre a través del sistema venoso. Nosotros reportamos a un niño de siete años de edad, con fístula arteriovenosa pulmonar difusa. Se revisaron en la literatura las ventajas y desventajas de cada método diagnóstico, concluyendo que la angiografía pulmonar sigue siendo de oro para el diagnóstico de esta enfermedad