Catálogo de publicaciones - revistas

<jats:p> Highlights from the <jats:italic>Science</jats:italic> family of journals </jats:p>

<jats:p>Editors’ selections from the current scientific literature</jats:p>

<jats:title>A Pickering-stabilized intracellular emulsion</jats:title> <jats:p> Pickering emulsions, droplet suspensions stabilized by solid particles, were discovered more than 100 years ago and are well studied in foods, oils, cosmetics, and pharmaceuticals. The particles adsorb to the droplet interface and prevent the emulsion from coarsening. Folkmann <jats:italic>et al</jats:italic> . report that P granules, biomolecular condensates in <jats:italic>Caenorhabditis elegans</jats:italic> , are an example of an intracellular Pickering emulsion (see the Perspective by Snead and Gladfelter). Biomolecular condensates are cellular compartments that form without traditional lipid membranes. This work raises the possibility that Pickering agents fulfill the role of membranes in biomolecular condensates. —DJ </jats:p>

<jats:title>Breaking down oxygen</jats:title> <jats:p> Molecular oxygen (O <jats:sub>2</jats:sub> ) is the terminal oxidant for respiration in mitochondria and many bacteria. Within membrane-bound heme–copper oxidases, a controlled, four-electron reduction of O <jats:sub>2</jats:sub> to water is coupled to pumping of protons across the membrane that can be used, among other outcomes, to generate adenosine triphosphate. Studying cytochrome <jats:italic>bo</jats:italic> <jats:sub>3</jats:sub> ubiquinol oxidase, Jose <jats:italic>et al</jats:italic> . investigated the key P <jats:sub>M</jats:sub> intermediate, which forms after O–O bond cleavage and precedes proton pumping, using magnetic circular dichroism spectroscopy. The authors observed features demonstrating that P <jats:sub>M</jats:sub> is a three-spin system, which is consistent with a consensus model including an iron(IV)-oxo species, copper(II) ion, and tyrosyl radical. These results provide an important validation of the O–O cleavage mechanism and open the door to understanding the proton pumping step. —MAF </jats:p>

<jats:title>A match made clear</jats:title> <jats:p> The fabrication of strong and tough composites is of interest in many technologies, such as the combination of mechanical performance with transparency for robust display systems. Amini <jats:italic>et al</jats:italic> . combined and centrifuged glass flakes with poly(methyl methacrylate) (PMMA) to make a transparent composite. By doping the glass flakes, it was possible to alter the refractive index of PMMA to maximize optical clarity. Such composites show good strength and toughness and could have a wide range of potential applications as an alternative to current glass composites. —MSL </jats:p>

<jats:title>Exploring cuprate chains</jats:title> <jats:p> Superconductivity in cuprates takes place in their two-dimensional (2D) layers but solving even the simplest model of interacting fermions in 2D is a challenge. The theory problem simplifies in 1D, with experiment becoming the tricky part. Chen <jats:italic>et al</jats:italic> . synthesized a cuprate that consists of parallel chains and behaves like a 1D system. Crucially, the material could be doped over a wide range of hole concentrations. The researchers showed that including a near-neighbor attractive interaction in a 1D model of interacting fermions was necessary to explain their photoemission measurements. —JS </jats:p>

<jats:title>Setting bounds on a fifth force</jats:title> <jats:p> Some extensions to the Standard Model of particle physics posit the existence of a fifth force to complement the existing four fundamental forces. To set bounds on the strength of such an interaction, experiments on vastly different length scales have been performed. Heacock <jats:italic>et al</jats:italic> . used an unusual method called Pendellösung interferometry to measure the neutron structure factors of silicon. The momentum dependence of the structure factors enabled the researchers to put more stringent bounds on the strength of a type of fifth force called the Yukawa force, as well as measure the charge radius of the neutron. —JS </jats:p>

<jats:title>Flexing computer memory</jats:title> <jats:p> Phase change materials leverage changes in structure into differences in electrical resistance that are attractive for computer memory and processing applications. Khan <jats:italic>et al</jats:italic> . developed a flexible phase change memory device with layers of antimony telluride and germanium telluride deposited directly on a flexible polyimide substrate. The device shows multilevel operation with a low switching current density. The combination of phase change and mechanical properties is attractive for the large number of emerging applications for flexible electronics. —BG </jats:p>