The use of functionalized magnetic particles for the detection or separation of multiple chemicals and biomolecules from biofluids continues to attract significant attention. After their incubation with the targeted substances, the beads can be magnetically recovered to perform analysis or diagnostic tests. Particle recovery with permanent magnets in continuous-flow microdevices has gathered great attention in the last decade due to the multiple advantages of microfluidics. As such, great efforts have been made to determine the magnetic and fluidic conditions for achieving complete particle capture; however, less attention has been paid to the effect of the channel geometry on the system performance, although it is key for designing systems that simultaneously provide high particle recovery and flow rates. Herein, we address the optimization of Y-Y-shaped microchannels, where magnetic beads are separated from blood and collected into a buffer stream by applying an external magnetic field. The influence of several geometrical features (namely cross section shape, thickness, length, and volume) on both bead recovery and system throughput is studied. For that purpose, we employ an experimentally validated Computational Fluid Dynamics (CFD) numerical model that considers the dominant forces acting on the beads during separation. Our results indicate that rectangular, long devices display the best performance as they deliver high particle recovery and high throughput. Thus, this methodology could be applied to the rational design of lab-on-a-chip devices for any magnetically driven purification, enrichment or isolation.

Young people have found in the social networks the perfect space to inform and be informed. However, only a few have the ability to influence in purchasing decisions, lifestyle or preferences of the rest. The so-called social influencers have become an active part of brand communication, especially those dedicated to fashion. This research puts the focus on the strategies, resources and calls to participation used for the main Spanish fashion prescribers in their communication through Instagram. The gradual incorporation of men into this sector requires identifying the attitudes and forms of the connection -generating participation- or not taking into account the genre of the author and the type of values he projects. Through content analysis, the communicative activity of the 13 most outstanding characteristics is monitored in 2017. The results show a very similar use of recovery techniques, mainly promotional; dubious compliance with Spanish regulations on advertising - which obliges authors to explicitly state any message that promotes a product or service of a contractual relationship; and the use of the image to build idyllic lives from everyday scenes.

Influencers, thanks to their ability to connect with the public, have revolutionized brand communication making it less invasive and at the same time attractive and dynamic. This research explores the behavior followed by the main Spanish fashion followers, focusing on the strategies and resources used in their communication through Instagram profiles. The gradual incorporation of men into this sector requires identifying whether the publication of habits in this social network vary or not with respect to the author’s gender. In addition, compliance with Spanish legislation on advertising is monitored, which obliges the authors to explicitly indicate any message that promotes a product or service from a contractual agreement.

No abstract

Trabajamos en un Territorio de Salud donde es fundamental estar formados y concienciados en anticoncepción porque los embarazos no deseados son un problema importante. Los métodos anticonceptivos que proporcionan una mayor efectividad son aquellos cuyo cumplimiento no depende de la paciente. Los implantes subdérmicos de etonogestrel son un método anticonceptivo eficaz, con pocas contraindicaciones y de fácil colocación, por lo que constituyen un método ideal para utilizar desde Atención Primaria. Palabras clave. Embarazo no Deseado, Anticoncepción, Implantes de Medicamentos.