Short mindfulness meditation training: does it really reduce perceived stress?

To study whether an 8-week mindfulness meditation training program truly reduces perceived stress without designing a stress reduction program. An experimental study was performed in which we studied the effects of 8 weeks of MM training on attention and awareness, as measured by the MAAS (mindfulness attention awareness scale) and perceived stress, as measured by the PSQ (perceived stress questionnaire), in 80 volunteers from the general public recruited by email from university centers. An increase in the individual's dispositional capacity to be attentive and aware of the experience of the present moment in everyday life was observed in the experimental group versus the control group; F (2, 156) = 14.30, p = .000, η2 partial = .155. Perceived stress showed no significant differences between groups in: social acceptance; F (2, 156) = 2.30, p = .103, overload; F (2, 156) = 2.32, p = .101, irritability, tension and fatigue; F (2, 156) = 2.27, p = .106, energy and joy; F (2, 156) = 2.79, p = .065. MM practice for 8 weeks of training increases the individual's dispositional capacity to be attentive and aware of the experience of the present moment in everyday life but may not reduce perceived stress.

Antiferromagnetic FeMn alloys electrodeposited from chloride-based electrolytes.

The capability of synthesizing Fe-based antiferromagnetic metal alloys would fuel the use of electrodeposition in the design of new magnetic devices such as high-aspect-ratio spin valves or new nanostructured hard magnetic composites. Here we report the synthesis of high quality antiferromagnetic FeMn alloys electrodeposited from chloride-based electrolytes. We have found that in order to grow homogeneous FeMn films it is necessary to incorporate a large concentration of NH4Cl as an additive in the electrolyte. The study of the structure and magnetic properties shows that films with composition close to Fe50Mn50 are homogeneous antiferromagnetic alloys. We have established a parameter window for the synthesis of FeMn alloys that show antiferromagnetism at room temperature.

Concomitant Light-Reversible Magnetic Response in Multiferroic Oxide Heterostructures for Multiphysics Applications.

The concept of multiphysics, where materials respond to diverse external stimuli, such as magnetic fields, electric fields, light irradiation, stress, heat, and chemical reactions, plays a fundamental role in the development of innovative devices. Nanomanufacturing, especially in low-dimensional systems, enhances the synergistic interactions taking place on the nanoscale. Light-matter interaction, rather than electric fields, holds great promise for achieving low-power, wireless control over magnetism, solving two major technological problems: the feasibility of electrical contacts at smaller scales and the undesired heating of the devices. Here, we shed light on the remarkable reversible modulation of magnetism using visible light in epitaxial Fe3O4/BaTiO3 heterostructure. This achievement is underpinned by the convergence of two distinct mechanisms. First, the magnetoelastic effect, triggered by ferroelectric domain switching, induces a proportional change in coercivity and remanence upon laser illumination. Second, light-matter interaction induces charged ferroelectric domain walls' electrostatic decompensations, acting intimately on the magnetization of the epitaxial Fe3O4 film by magnetoelectric coupling. Crucially, our experimental results vividly illustrate the capability to manipulate magnetic properties using visible light. This concomitant mechanism provides a promising avenue for low-intensity visible-light manipulation of magnetism, offering potential applications in multiferroic devices.

Single alloy nanoparticle x-ray imaging during a catalytic reaction.

The imaging of active nanoparticles represents a milestone in decoding heterogeneous catalysts' dynamics. We report the facet-resolved, surface strain state of a single PtRh alloy nanoparticle on SrTiO3 determined by coherent x-ray diffraction imaging under catalytic reaction conditions. Density functional theory calculations allow us to correlate the facet surface strain state to its reaction environment­dependent chemical composition. We find that the initially Pt-terminated nanoparticle surface gets Rh-enriched under CO oxidation reaction conditions. The local composition is facet orientation dependent, and the Rh enrichment is nonreversible under subsequent CO reduction. Tracking facet-resolved strain and composition under operando conditions is crucial for a rational design of more efficient heterogeneous catalysts with tailored activity, selectivity, and lifetime.