Catálogo de publicaciones - revistas

<jats:title>Watching plasmonic skyrmions</jats:title> <jats:p> Skyrmions are stable topological textures that arise from solutions of the electromagnetic field. Because these “hedgehog”-like textures are robust, can be manipulated, and can interact, there is an interest in pursuing them for memory and logic applications. Skyrmions can also be generated in thin metal layers under optical excitation, but detailed information about the vectorial dynamics of these surface plasmon polariton skyrmions is so far lacking. Davis <jats:italic>et al.</jats:italic> used a time-resolved photoelectron vector microscope to image their spatiotemporal dynamics, piecing together movies as the skyrmions propagated across the surface of a perfect gold crystal. Access to dynamics with such high spatial and temporal resolution could help in controlling other nanophotonic systems. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aba6415">eaba6415</jats:related-article> </jats:p>

<jats:title>A close-up view of the retrotranslocon</jats:title> <jats:p> Misfolded endoplasmic reticulum (ER) proteins are retrotranslocated into the cytosol, polyubiquitinated, and degraded by the proteasome in a process known as ER-associated protein degradation (ERAD). ERAD of misfolded luminal ER proteins (ERAD-L) is mediated by the Hrd1 complex, composed of the ubiquitin ligase Hrd1 and four additional proteins (Hrd3, Der1, Usa1, and Yos9). Wu <jats:italic>et al.</jats:italic> report a cryo–electron microscopy structure of the active Hrd1 complex from yeast and, based on this structure, developed a model for how substrates are recognized and retrotranslocated. They propose that Hrd3 and Yos9 jointly create a luminal binding site for misfolded glycoproteins. Hrd1 and Der1 form “half-channels” juxtaposed in a thinned section of the ER membrane, which allows a polypeptide loop of an ERAD-L substrate to move through it. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aaz2449">eaaz2449</jats:related-article> </jats:p>

<jats:title>Proteostasis dISRupted</jats:title> <jats:p>Despite their importance, many crucial networks for protein quality control within cells diminish with age. The resulting loss of proteostasis, the process by which the health of a cell's proteins is monitored and maintained, is associated with a wide range of age-related human diseases. Costa-Mattioli and Walter review the integrated stress response (ISR), a central signaling network that responds to proteostasis defects by tuning protein synthesis. The ISR is activated in a wide range of pathological conditions, so a mechanistic understanding of its pathway may help in the development of therapeutic tools through which it can be modulated.</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aat5314">eaat5314</jats:related-article> </jats:p>

<jats:p>Pandemics are international. A virus doesn't respect borders between countries—or between states, as we are seeing with severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) in the United States. Unfortunately, too many world leaders want to treat the situation as a problem for their nation alone and not the world.</jats:p>

<jats:p>Coronavirus disease 2019 (COVID-19) has been the greatest disruption to the movement of people since World War II. Many who had plans—and permission—to move permanently from one country to another have seen their transition put on hold. Worldwide, the flows of tourists, business and professional travelers, and students are all affected. But those most vulnerable to the virus and virus-related policies are low-paid migrant workers who have lost their jobs, and refugees or displaced people. Their lives were precarious even before the pandemic spread.</jats:p>

<jats:p>A roundup of weekly science policy and related news.</jats:p>

<jats:p>Some study authors use serology data to call for easing lockdowns, but critics push back.</jats:p>

<jats:p>Firms to help prioritize treatment and vaccine trials.</jats:p>

<jats:p>Other infections and scant medical care may worsen toll.</jats:p>

<jats:p>Studies find benefit to testing thousands of children for antibodies that precede symptoms.</jats:p>