Structural determination of Bi-doped magnetite multifunctional nanoparticles for contrast imaging

To determine with precision how Bi atoms are distributed in Bi-doped iron oxide nanoparticles their structural characterization has been carried out by X-ray absorption spectroscopy (XAS) recorded at the K edge of Fe and at the L edge of Bi. The inorganic nanoparticles are nominally hybrid structures integrating an iron oxide core and a bismuth oxide shell. Fe K-edge XAS indicates the formation of a structurally ordered, non-stoichiometric magnetite (FeO) phase for all the nanoparticles. The XAS spectra show that, in the samples synthesized by precipitation in aqueous media and laser pyrolysis, the Bi atoms neither enter into the iron oxide spinel lattice nor form any other mixed Bi-Fe oxides. No modification of the local structure around the Fe atoms induced by the Bi atoms is observed at the Fe K edge. In addition, contrary to expectations, our results indicate that the Bi atoms do not form a well-defined Bi oxide structure. The XAS study at the Bi L edge indicates that the environment around Bi atoms is highly disordered and only a first oxygen coordination shell is observed. Indefinite [BiO(OH)] units (isolated or aggregated forming tiny amorphous clusters) bonded through hydroxyl bridges to the nanoparticle, rather than a well defined BiO shell, surround the nanoparticle. On the other hand, the XAS study indicates that, in the samples synthesized by thermal decomposition, the Bi atoms are embedded in a longer range ordered structure showing the first and second neighbors

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Structural determination of Bi-doped magnetite multifunctional nanoparticles for contrast imaging

To determine with precision how Bi atoms are distributed in Bi-doped iron oxide nanoparticles their structural characterization has been carried out by X-ray absorption spectroscopy (XAS) recorded at the K edge of Fe and at the L edge of Bi. The inorganic nanoparticles are nominally hybrid structures integrating an iron oxide core and a bismuth oxide shell. Fe K-edge XAS indicates the formation of a structurally ordered, non-stoichiometric magnetite (FeO) phase for all the nanoparticles. The XAS spectra show that, in the samples synthesized by precipitation in aqueous media and laser pyrolysis, the Bi atoms neither enter into the iron oxide spinel lattice nor form any other mixed Bi-Fe oxides. No modification of the local structure around the Fe atoms induced by the Bi atoms is observed at the Fe K edge. In addition, contrary to expectations, our results indicate that the Bi atoms do not form a well-defined Bi oxide structure. The XAS study at the Bi L edge indicates that the environment around Bi atoms is highly disordered and only a first oxygen coordination shell is observed. Indefinite [BiO(OH)] units (isolated or aggregated forming tiny amorphous clusters) bonded through hydroxyl bridges to the nanoparticle, rather than a well defined BiO shell, surround the nanoparticle. On the other hand, the XAS study indicates that, in the samples synthesized by thermal decomposition, the Bi atoms are embedded in a longer range ordered structure showing the first and second neighbors

Reflexiones sobre la educación en diseño en contextos de emergencia

El libro que tiene en sus manos representa el esfuerzo y compromiso que la planta académica de la División de Ciencias y Artes para el Diseño ha asumido durante la pandemia COVID-19, pasar de un aprendizaje tradicional a un aprendizaje digital, para continuar cumpliendo con el compromiso de nuestra institución: formar ciudadanos y profesionistas de alto nivel. Este libro respeta los cinco ejes temáticos propuestos por el comité organizador. 1. Transición de la enseñanza-aprendizaje mediada por tecnologías digitales. 2. Experiencias significativas para los actores (docentes u alumnos). 3. Propuesta pedagógica innovadora. 4. Reflexión sobre la apropiación de las tecnologías digitales y recursos. 5. Diseño de futuros para una educación en diseño. Cada uno de los artículos que integran esta obra está asociado a alguno de estos ejes. En conjunto representan la base de una gran oportunidad que tiene nuestra División para reinventarse y diversificar las experiencias de aprendizaje además de la modalidad presencial. A esta reflexión colectiva también se han sumado las ideas de profesoras y profesores de otras instituciones, con lo cual la experiencia se ha enriquecido aún más al identificar obstáculos y retos compartidos. Hemos descubierto el potencial de la educación digital y dependerá de nosotros el diseñar las estrategias para aprender a convivir también con la educación presencial. Debemos reconocer que las y los profesores no estaban capacitados para un aprendizaje digital, situación no exclusiva de nuestra casa de estudios, en la mayoría de instituciones del sistema de educación superior tampoco estaban preparados. Además de resaltar la falta de políticas de inclusión para favorecer un aprendizaje digital. Estas dos ideas se vuelven elementos centrales para que las universidades asuman un mayor compromiso al respecto.Coordinadoras e [introducción]: Juana Cecilia Ángeles Cañedo y Alma Elisa Delgado Coellar; [Presentación] 2o. Coloquio de Educación en Diseño / Marco Vinicio Ferruzca Navarro; coordinación editorial: Alma Elisa Delgado Coellar y Martha Ivonne Murillo Islas; diseño de interiores, de portada y formación de interiores: Martha Ivonne Murillo Islas; corrección de estilo: Agustina Larrañaga