Revista complutense de educación

Resumen basado en el de la publicaciónSe lleva a cabo una revisión general del procedimiento cloze, procedimiento que es ampliamente conocido y utilizado como instrumento de evaluación de la lectura en los países de habla inglesa pero que apenas es conocido y empleado en España. Dicha revisión hace referencia tanto a los aspectos metodológicos relacionados con dicho procedimiento como a los distintos usos para los que puede emplearse en el campo de la evaluación de la lectura.ES

Stable Magnetic Skyrmion States at Room Temperature Confined to Corrals of Artificial Surface Pits Fabricated by a Focused Electron Beam

Stable confinement of elemental magnetic nanostructures, such as a single magnetic domain, is fundamental in modern magnetic recording technology. It is well-known that various magnetic textures can be stabilized by geometrical confinement using artificial nanostructures. The magnetic skyrmion, with novel spin texture and promise for future memory devices because of its topological protection and dimension at the nanometer scale, is no exception. So far, skyrmion confinement techniques using large-scale boundaries with limited geometries such as isolated disks and stripes prepared by conventional microfabrication techniques have been used. Here, we demonstrate an alternative technique confining skyrmions to artificial nanostructures (corrals) built from surface pits fabricated by a focused electron beam. Using aberration-corrected differential phase contrast scanning transmission electron microscopy, we directly visualized stable skyrmion states confined at a room temperature to corrals made of artificial surface pits on a thin plate of Co₈Zn₈Mn₄. We observed a stable single-skyrmion state confined to a triangular corral and a unique transition into a triple-skyrmions state depending on the perpendicular magnetic field. Furthermore, we made an array of stable single-skyrmion states by using concatenated triangular corrals. Artificial control of skyrmion states with the present technique should be a powerful way to realize future nonvolatile memory devices using skyrmions

Additional file 2: of Yields and chondrogenic potential of primary synovial mesenchymal stem cells are comparable between rheumatoid arthritis and osteoarthritis patients

Representative raw data for surface markers. Flow cytometric analyses of digested cells before plating (day 0) and expanded cells cultured for 14 days. Donor number of RA and OA patients shown. (DOCX 16 kb

Probing the Internal Atomic Charge Density Distributions in Real Space

Probing the charge density distributions in materials at atomic scale remains an extremely demanding task, particularly in real space. However, recent advances in differential phase contrast-scanning transmission electron microscopy (DPC-STEM) bring this possibility closer by directly visualizing the atomic electric field. DPC-STEM at atomic resolutions measures how a sub-angstrom electron probe passing through a material is affected by the atomic electric field, the field between the nucleus and the surrounding electrons. Here, we perform a fully quantitative analysis which allows us to probe the charge density distributions inside atoms, including both the positive nuclear and the screening electronic charges, with subatomic resolution and in real space. By combining state-of-the-art DPC-STEM experiments with advanced electron scattering simulations we are able to map the spatial distribution of the electron cloud within individual atomic columns. This work constitutes a crucial step toward the direct atomic scale determination of the local charge redistributions and modulations taking place in materials systems