Catálogo de publicaciones - revistas

<jats:title>Cassini's last look at Saturn's rings</jats:title> <jats:p> During the final stages of the Cassini mission, the spacecraft flew between the planet and its rings, providing a new view on this spectacular system (see the Perspective by Ida). Setting the scene, Spilker reviews the numerous discoveries made using Cassini during the 13 years it spent orbiting Saturn. Iess <jats:italic>et al.</jats:italic> measured the gravitational pull on Cassini, separating the contributions from the planet and the rings. This allowed them to determine the interior structure of Saturn and the mass of its rings. Buratti <jats:italic>et al.</jats:italic> present observations of five small moons located in and around the rings. The moons each have distinctive shapes and compositions, owing to accretion of ring material. Tiscareno <jats:italic>et al.</jats:italic> observed the rings directly at close range, finding complex features sculpted by the gravitational interactions between moons and ring particles. Together, these results show that Saturn's rings are substantially younger than the planet itself and constrain models of their origin. </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" issue="6445" page="1046" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aat3760">1046</jats:related-article> , 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.aat2965">eaat2965</jats:related-article> , 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.aat2349">eaat2349</jats:related-article> , 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.aau1017">eaau1017</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1028" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw3098">1028</jats:related-article> </jats:p>

<jats:title>Supported graphene-based membranes</jats:title> <jats:p> Porous graphene sheets have excellent filtration capabilities and are able to block most ions, but their fragility limits their scale-up beyond laboratory demonstrations. Yang <jats:italic>et al.</jats:italic> created a nanoporous graphene membrane reinforced by a network of single-walled carbon nanotubes (SWNTs) to provide mechanical stability (see the Perspective by Mi). The SWNT network also stopped the propagation of cracks in the graphene, effectively localizing the damage to a small area defined by a cell in the carbon nanotube mesh. The membranes showed high water flux rates as well as a high rejection rate for most ions. </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" issue="6445" page="1057" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aau5321">1057</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1033" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aax3103">1033</jats:related-article> </jats:p>

<jats:title>Structural switch for fast switching</jats:title> <jats:p> Phase-change materials are important for computer memory. They can quickly switch from glassy to crystalline using a thermal pulse and then lock in that structure for a long time at lower temperature. Zalden <jats:italic>et al.</jats:italic> probed the underlying atomic structure of two phase-change materials during this switching using ultrafast x-rays and simulations (see the Perspective by Rao <jats:italic>et al.</jats:italic> ). A liquid-liquid phase transition in both materials allowed fast switching at high temperatures. The lower-temperature glass locks in the structure, allowing for long-term memory storage. </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" issue="6445" page="1062" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw1773">1062</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1032" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aax6333">1032</jats:related-article> </jats:p>

<jats:title>ATP production under lockdown</jats:title> <jats:p> Cellular processes must respond to change, often by speeding up, slowing down, or stopping altogether. Adenosine triphosphate (ATP) synthases use a transmembrane proton gradient to produce ATP, but this reaction can go in reverse and needs to be halted when conditions are unfavorable. Jinke Gu <jats:italic>et al.</jats:italic> purified a tetrameric ATP synthase complex from pig hearts that contained the endogenous inhibitory protein IF1. Targeted refinement yielded high-resolution views of the mammalian ATP synthase trapped in two different rotation states by IF1. The findings suggest that ATP synthase tetramers can be inhibited by at least three different mechanisms. </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" issue="6445" page="1068" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw4852">1068</jats:related-article> </jats:p>