Influencia de las condiciones de coprecipitación de NixMnyCoz(OH)2, utilizados como precursores en cátodos de baterías de ión litio [= Influence of coprecipitation condition of NixMnyCoz(OH)2, used as precursor in ion lithium batteries cathodes]

Las baterías de iones de litio abundan en una gran variedad de dispositivos. Dentro de los cátodos tradicionales se encuentran los óxidos de litio y metales de transición (ej. LiCoO2) que son de fácil preparación y tienen un buen rendimiento. Recientemente, se han desarrollado nuevas composiciones para los cátodos, como por ejemplo Li(NixMnyCoz)O2 (x+y+z=1) ya que presenta ventajas porque reduce los altos costos y la toxicidad asociados con el cobalto, y presenta un buen balance entre capacidad, ciclablidad y estabilidad térmica.[1] Estos cátodos se puede obtener por calcinación del precursor NixMnyCoz(OH)2 (hidróxido de NMC) con LiOH. Un método económico y escalable para sintetizar hidróxido de NMC es mediante la coprecipitación de los metales de transición con un agente acomplejante en medio básico. Existen datos experimentales limitados sobre este proceso de coprecipitación y su influencia en las características de las partículas primarias resultantes, como su distribución de tamaño (PSD), área superficial y porosidad. Además, existen pocos modelos computacionales que brinden una herramienta predictiva para determinar las características mencionadas anteriormente y para comprenderla influencia del mezclado en la precipitación de partículas. En este trabajo, proponemos el estudio sistemático de la influencia de las condiciones de síntesis en la coprecipitación para posteriormente validar un nuevo marco computacional que permita predecir la coprecipitación de los hidróxidos de NMC. Finalmente, estudiar la relación entre las características del hidróxido obtenido como morfología, tap densidad, PSD y el comportamiento electroquímico del óxido obtenido a partir del mismo. Los hidróxidos de NMC se sintetizaron a través de un proceso de coprecipitación que se llevó a cabo dentro de un reactor de vórtice a microescala con cuatro entradas, cada una para el ingreso de las soluciones a la cámara de mezclado. Todos los experimentos se realizaron bajo atmósfera de N2, variando las proporciones de Ni, Mn y Co, y las velocidades de flujo. Las partículas resultantes se caracterizaron para evaluar la tap densidad, la PSD y la morfología, con DLS, SEM. Finalmente, el Li(NixMnyCoz)O2 obtenido de cada hidróxido se utilizó como cátodo y se caracterizó electroquímicamente analizando su capacidad específica y ciclabilidad, en celdas botón. The research reported in this paper was funded by European Union, Horizon 2020 Programme, SimDome Project, Grant Agreement No 814492. The views and opinions expressed in this publication are the sole responsibility of the author(s) and do not necessarily reflect the views of the European Commission/Research Executive Agency

Consistent and reproducible outcomes of blastocyst biopsy and aneuploidy screening across different biopsy practitioners: a multicentre study involving 2586 embryo biopsies

Is blastocyst biopsy and quantitative real-time PCR based comprehensive chromosome screening a consistent and reproducible approach across different biopsy practitioners

Heterogeneity and bipotency of astroglial-like cerebellar progenitors along the interneuron and glial lineages

© 2015 the authors. Cerebellar GABAergic interneurons in mouse comprise multiple subsets of morphologically and neurochemically distinct phenotypes located at strategic nodes of cerebellar local circuits. These cells are produced by common progenitors deriving from the ventricular epithelium during embryogenesis and from the prospective white matter (PWM) during postnatal development. However, it is not clear whether these progenitors are also shared by other cerebellar lineages and whether germinative sites different from the PWM originate inhibitory interneurons. Indeed, the postnatal cerebellum hosts another germinal site along the Purkinje cell layer (PCL), in which Bergmann glia are generated up to first the postnatal weeks, which was proposed to be neurogenic. Both PCL and PWM comprise precursors displaying traits of juvenile astroglia and neural stem cell markers. First, we examine the proliferative and fate potential of these niches, showing that different proliferative dynamics regulate progenitor amplification at these sites. In addition, PCL and PWM differ in the generated progeny. GABAergic interneurons are produced exclusively by PWM astroglial-like progenitors, whereas PCL precursors produce only astrocytes. Finally, through in vitro, ex vivo, and in vivo clonal analyses we provide evidence that the postnatal PWM hosts a bipotent progenitor that gives rise to both interneurons and white matter astrocytes.Peer Reviewe

Ontogenesis of glial diversity in the cerebellum as revealed through quantitative in vivo clonal analyses

Trabajo presentado en GLIA 2019: XIV European Meeting on Glial Cells in Health and disease en Oporto el 10 de Julio de 2019.In the cerebellum, astrocytes (AS) and oligodendrocytes (OLs) are characterized by a peculiar phenotypic heterogeneity, closely related to specific functional features. Nevertheless, the ontogenesis of this glial diversity remains poorly understood. By combining in vivo clonal analyses employing StarTrack plasmids and Confetti mice withproliferation studies, we have recently demonstrated that the major cerebellar AS types derive from embryonic and postnatal progenitors with diverse lineage potentials. Moreover, AS heterogeneity appeared to emerge according to an unprecedented and remarkably orderly developmental program, likely driven by deterministic components as suggested by in silico simulations. Similar StarTrack clonal analyses are now being applied to elucidate the origins, clonal relationships, and spatial distribution of cerebellar OLs born at distinct developmental stages. While AS clones showed a time-dependent allocation first to the hemispheres and then to the vermis, preliminary data indicate that OL clones are not medio-laterally compartmentalised, being capable of populating either of the two regions independently from their developmental origin. This suggests that the two progenitor pools, originally spatially segregated, also follow distinct guidance mechanisms to populate different cerebellar territories within the same developmental time window. On the other side, both AS and OLs displayed a similar behaviour along the antero-posterior axis: cells belonging to distinct clones rarely intermingled and, rather, clustered to populate discrete cerebellar lobules, thereby suggesting that each AS or OL clone is involved in the functional maturation and/or maintenance of specific neural circuit compartments, with poor contributions from others. Last, similarly to AS clones characterized by stereotyped architectures and recurrent modularities, immunohistochemical and morphological analyses of the cells strikingly highlighted that OL clones have a constant relative contribution of immature and mature cells, in favour of the mature part. While the modularity in AS clones was demonstrated to reflect layer-specific dynamics of postnatal proliferation/differentiation, what determines the equilibrium between immature and post-mitotic cells in OL clones is unknown. It will be interesting to investigate whether it reflects intrinsic properties of the progenitors themselves or it depends upon extrinsic cues, such as the surrounding axonal availability