Catálogo de publicaciones - revistas

<jats:title>Lower-cost thermoelectrics</jats:title> <jats:p> Thermoelectric materials convert heat to electricity, making them attractive for heat harvesting or cooling applications. However, many high-performance thermoelectrics are made of expensive or toxic materials. He <jats:italic>et al.</jats:italic> found that a material composed of primarily tin and sulfur could be optimized to have relatively good thermoelectric properties. Introducing about 10% selenium to tin sulfide helped tune these properties by electronic band manipulation. This material is a step toward more earth-abundant, less toxic, and lower-cost thermoelectrics than the telluride-based materials currently in use. </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="6460" page="1418" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aax5123">1418</jats:related-article> </jats:p>

<jats:title>Tweaking the Hubbard model</jats:title> <jats:p>Modeling high-temperature superconductivity (HTS) remains extremely challenging. Many researchers believe that the simplest model that captures HTS is the Hubbard model, which accounts for interactions and allows for electrons to hop from one site of a lattice to another. However, even just determining whether the ground state of this model supports superconductivity is tricky. Jiang and Devereaux undertook an extensive computational study based on a method known as density matrix renormalization group. They found that for a particular concentration of empty lattice sites, superconductivity indeed appears as a long-range state, but only if electrons are allowed to hop to sites that are next to their immediate neighbors on the lattice.</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="6460" page="1424" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aal5304">1424</jats:related-article> </jats:p>

<jats:title>Microbial entrainment of metabolism</jats:title> <jats:p> The metabolism of mammals is synchronized to daily cycles relating to sleep and mealtimes. It is not surprising that the gut microbiota, which aids in digestion, should also display daily cycling. Kuang <jats:italic>et al.</jats:italic> found that the gut microbiota can mediate daily cycles epigenetically (see the Perspective by Bishehsari and Keshavarzian). The microbiota induces rhythmic expression of histone deacetylase 3 (HDAC3) in epithelial cells of the small intestine, but not those of the colon. HDAC3 expression drives oscillations in intestinal metabolic gene expression, especially for nutrient transport and lipid metabolism. HDAC3 also directly activates estrogen-related receptor α, which promotes lipid absorption. Consequently, mice that lack a gut microbiota lack daily regulation of their metabolism and become obese on high-fat chow. Disruption of HDAC3 cycling could be an explanation for human obesity associated with antibiotic damage to the microbiota and with sleep disruption caused by jet lag and nighttime working. </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="6460" page="1428" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw3134">1428</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6460" page="1379" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaz0224">1379</jats:related-article> </jats:p>

<jats:title>Responding to the cold</jats:title> <jats:p> Mint tastes cool because the active component, menthol, activates the receptor and calcium channel TRPM8, which also responds to cold temperatures. Previous structures have revealed the architecture of TRPM8 and how it binds ligands but not its gating mechanism. Diver <jats:italic>et al.</jats:italic> determined structures of avian TRPM8 in ligand-free, antagonist-bound, and calcium-bound states using cryo–electron microscopy at resolutions between 3.0 and 3.6 angstroms. They observed a closed state in the presence of antagonist and that large conformational changes are required to form the desensitized state in the presence of calcium. Understanding how ligands affect channel gating may facilitate drug design. </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="6460" page="1434" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aax6672">1434</jats:related-article> </jats:p>

<jats:title>A small star hosts a big planet</jats:title> <jats:p> M dwarfs, the most common type of star, are low-mass objects that emit most of their faint light in the near-infrared, making it difficult to detect any orbiting exoplanets. Morales <jats:italic>et al.</jats:italic> have observed the nearby M dwarf GJ 3512 in the optical and near-infrared (see the Perspective by Laughlin). Periodic variations in the star's radial velocity show that it hosts a gas giant exoplanet on an eccentric orbit. The authors use simulations to show that such a large exoplanet around such a small star has implications for models of planet formation. </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="6460" page="1441" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aax3198">1441</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6460" page="1382" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aay7775">1382</jats:related-article> </jats:p>