Catálogo de publicaciones - revistas

<jats:title>General relativity weighs a white dwarf</jats:title> <jats:p> Light from a background star is deflected by the gravitational field of the Sun. This effect was used in 1919 to provide some of the first evidence for general relativity. Sahu <jats:italic>et al.</jats:italic> applied the concept to another star: a nearby white dwarf called Stein 2051 B, which passed close in front of a more distant normal star (see the Perspective by Oswalt). The authors measured the tiny shifts in the apparent position of the background star, an effect called astrometric microlensing. The apparent motion matched the predictions of general relativity, which allowed the authors to determine the mass of the white dwarf. </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="6342" page="1046" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aal2879">1046</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6342" page="1015" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aan2996">1015</jats:related-article> </jats:p>

<jats:title>Selfish genetic interactions in nematodes</jats:title> <jats:p> Identifying the effects and evolution of selfish genetic elements can be difficult because of their biased inheritance. Ben-David <jats:italic>et al.</jats:italic> identified a selfish genetic element that drives maternal-effect lethality in the nematode <jats:italic>Caenorhabditis elegans</jats:italic> (see the Perspective by Phadnis). This incompatibility stems from the interaction between a maternally deposited toxin and a zygotically expressed antidote. Interestingly, the antidote is encoded by the gene <jats:italic>pha-1</jats:italic> , which has been described as an essential gene in embryonic development. </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="6342" page="1051" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aan0621">1051</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6342" page="1013" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aan6119">1013</jats:related-article> </jats:p>

<jats:title>Sighting of magnetic Majorana fermions?</jats:title><jats:p>Quantum spin liquids—materials whose magnetic spins do not settle into order even at absolute zero temperature—have long captured the interest of physicists. A particularly lofty goal is finding a material that can be described by the so-called Kitaev spin model, a network of spins on a honeycomb lattice that harbors Majorana fermions as its excitations. Banerjee<jats:italic>et al.</jats:italic>present a comprehensive inelastic neutron scattering study of single crystals of the material α-RuCl<jats:sub>3</jats:sub>, which has been predicted to a host a Kitaev spin liquid. The unusual dependence of the data on energy, momentum, and temperature is consistent with the Kitaev model.</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="6342" page="1055" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aah6015">1055</jats:related-article></jats:p>

<jats:title>Teaching sulfur and phosphorus to share</jats:title> <jats:p> Wouldn't it be nice if real chemistry worked like a modeling kit, and you could just pull a group off one molecule and tack it onto another? Lian <jats:italic>et al.</jats:italic> report that palladium catalysis can swap aryl rings between pairs of organosulfur or organophosphorus fragments in just this way. They showcase the sulfur swap by breaking down the commercial thermoplastic polyphenylene sulfide into simple monomers. </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="6342" page="1059" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aam9041">1059</jats:related-article> </jats:p>

<jats:title>Designing molecular disorder</jats:title> <jats:p> Melanins are a group of natural pigments that are the primary factor affecting skin color. Lampel <jats:italic>et al.</jats:italic> examined a family of melanin-inspired materials based on tripeptides containing tyrosine as precursors for polymeric pigments. They found that the supramolecular organization of the tripeptide assembly is the most important factor for the enzymatic oxidation, with the position of the tyrosine residue playing a dominant role. Thus, simply juggling the order of the peptides allowed tuning of the optical and electrical properties of the resulting polymers. </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="6342" page="1064" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aal5005">1064</jats:related-article> </jats:p>

<jats:title>Comets contributed to Earth's atmosphere</jats:title> <jats:p> Models of xenon's origin in Earth's atmosphere require an additional, unknown source that has been a mystery for several decades. Marty <jats:italic>et al.</jats:italic> measured isotopic ratios of xenon released from comet 67P/Churyumov-Gerasimenko and found that they match the heretofore unknown source. The xenon appears to have been trapped in ice within the comet since before the solar system formed. Comets contributed about a quarter of the xenon on Earth, which constrains the amount of other materials (such as water) delivered to our planet by comets. </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="6342" page="1069" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aal3496">1069</jats:related-article> </jats:p>