University of Tarapacá

Green synthesis of nanoparticles (NPs) has garnered a considerable amount of attention lately due to its low production expenses, simplicity of manufacturing, safety, and environmental friendliness. It is a dependable method for creating a variety of nanostructures from fungal, plant, and bacterial extracts as well as hybrid materials, including metal salts. A viable and sustainable substitute for traditional synthesis methods is the green synthesis of NPs. According to recent research, NPs have very promising antiviral and antimicrobial capabilities. This article highlights the progress made in the green method for manufacturing NPs utilizing natural substances, including fruit juices, plant extracts, and other pertinent sources. A thorough understanding of these NPs' anticancer, antiviral, and antimicrobial abilities was presented. Numerous opportunities are presented by these NPs to combat potentially fatal viral and other antimicrobial diseases. This review provides readers with a grasp of the latest data and a variety of tactics for designing and developing advanced green nanomaterials using a more environmentally friendly approach. A summary is provided of the present difficulties, critical analysis, and prospects for the green synthesis of NPs as well as the potential for their innovative and successful investigation for biomedical applications. • Green synthesis of NPs is eco-friendly, cost-effective, and simple to produce. • Natural sources like plant extracts enable sustainable nanoparticle fabrication. • Green NPs show promising antiviral, antimicrobial, and anticancer properties. • Challenges and future prospects highlight the potential of eco-friendly nanomedicine.

Changing-state active galactic nuclei (CSAGNs) exhibit rapid variability; their mass accretion rates can change by several orders of magnitude in a few years. This provides us with a unique opportunity to study the evolution of the inner accretion flow almost in real time. Here we used over 1000 observations to study the broadband X-ray spectra of a sample of five CSAGNs, spanning three orders of magnitude in Eddington ratio ( λ Edd ), using phenomenological models to trace the evolution of key spectral components. We derive several fundamental parameters, such as the photon index, soft excess strength, reflection strength, and luminosities of the soft excess and primary continuum. We find that the soft excess and primary continuum emissions show a very strong positive correlation ( p ≪ 10 −10 ), suggesting a common physical origin. The soft excess strength does not show any dependence on the reflection parameter, suggesting that in these objects the soft excess is not dominated by a blurred ionized reflection process. On the other hand, the strength of the soft excess is found to be strongly positively correlated with the Eddington ratio ( p ≪ 10 −10 ), and we find that the soft excess vanishes below log λ Edd ∼ −2.5. Moreover, we find a clear V-shaped relation for Γ − λ Edd , with a break at log λ Edd = −2.47 ± 0.09. Our findings indicate a change in the geometry of the inner accretion flow at low Eddington ratios, and that the soft excess is primarily produced via warm Comptonization.

El articulo indaga en las tensiones generadas en la frontera entre Bolivia y Chile durante la última década y, particularmente, desde el comienzo de la pandemia de Covid-19, debido al masivo arribo de migrantes provenientes del norte de Sudamérica y del Caribe, principalmente de Venezuela, a Chile. Para dar cuenta de ello, se aplicó una etnografía estratégicamente situada en el altiplano andino, específicamente en los pueblos de Colchane (Chile) y Pisiga Bolívar (Bolivia), durante la segunda mitad de 2021 y a lo largo de 2022. La investigación sugiere que el régimen de control fronterizo —y su consecuente proceso de securitización y militarización— no cumplieron con los propósitos de controlar el ingreso irregular, sino, más bien, han estimulado durante quince años la hípervulnerabilización y el tráfico de personas (coyotaje). La razón principal que se esgrime es el centralismo en la toma de decisiones. Asimismo, se argumenta que estas medidas no tuvieron en cuenta las necesidades de la población indígena local, perjudicando la convivencia y las prácticas transfronterizas de estas comunidades aymaras. Por último, se sostiene que la implementación de este régimen reprodujo dinámicas de xenofobia, las cuales se presentan de forma aporofóbica.