Catálogo de publicaciones - revistas

<jats:title>A twisty trilayer</jats:title> <jats:p> The discovery of superconductivity in bilayers consisting of graphene sheets twisted with respect to each other by just the right “magic” angle has inspired enormous interest in twisted materials. Hao <jats:italic>et al.</jats:italic> constructed twisted trilayer graphene, in which the middle layer is twisted with respect to the bottom layer and the top layer is roughly parallel to the bottom layer (see the Perspective by Yazdani). Such trilayers exhibited superconductivity that was tunable by an external electric field and consistent with having an unconventional nature. </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="6534" page="1133" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg0399">1133</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6534" page="1098" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg5641">1098</jats:related-article> </jats:p>

<jats:title>Eluding detection</jats:title> <jats:p> Influenza viruses evade immunity initiated by previous infection, which explains recurrent influenza pandemics. Unlike the error-prone RNA-dependent RNA polymerase of influenza, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and related viruses contain polymerases with proofreading activity. However, proofreading cannot correct deletions, which during a long-term persistent infection could result in the generation of viruses showing alteration of entire stretches of amino acids and the structures they form. McCarthy <jats:italic>et al.</jats:italic> identified an evolutionary signature defined by prevalent and recurrent deletions in the spike protein of SARS-CoV-2 at four antigenic sites. Deletion variants show human-to-human transmission of viruses with altered antigenicity. </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="6534" page="1139" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abf6950">1139</jats:related-article> </jats:p>

<jats:title>Hydrogenating borophene</jats:title> <jats:p> The two-dimensional material borophene, which is formed on silver surfaces, has a diverse polymorphism and is predicted to have unusual materials and electronic properties. However, it is highly unstable outside of ultrahigh vacuum conditions and oxidizes readily, which hampers exploration of its properties. Li <jats:italic>et al.</jats:italic> hydrogenated these materials with atomic hydrogen and showed that borophane has a lower local work function. This material is stable for days in air, and borophene can be recovered simply by thermally driving off the hydrogen. </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="6534" page="1143" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg1874">1143</jats:related-article> </jats:p>

<jats:title>Getting more pumped</jats:title> <jats:p> It is thought that the ocean's biological carbon pump, the process that transfers organic matter from the surface to the deep ocean, should be sensitive to climate change because temperature controls photosynthesis and respiration rates. Boscolo-Galazzo <jats:italic>et al.</jats:italic> show that the efficiency of the biological carbon pump increased over the past 15 million years as the oceans cooled because of a reduction in the rate of the breakdown of sinking organic matter (see the Perspective by Bopp). The resulting redistribution of nutrients at depth could have affected plankton evolution and expanded the mesopelagic “twilight zone” ecosystem. </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="6534" page="1148" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abb6643">1148</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6534" page="1099" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg5994">1099</jats:related-article> </jats:p>

<jats:title>Vaccine protects against B1.1.7 variant</jats:title> <jats:p> The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B1.1.7 (VOC 202012/01) variant that emerged in late 2020 in the United Kingdom has many changes in the spike protein gene. Three of these are associated with enhanced infectivity and transmissibility, and there are concerns that B.1.1.7 might compromise the effectiveness of the vaccine. Muik <jats:italic>et al.</jats:italic> compared the neutralization efficacy of sera from 40 subjects immunized with the BioNTech-Pfizer mRNA vaccine BNT162b2 against a pseudovirus bearing the Wuhan reference strain or the lineage B.1.1.7 spike protein (see the Perspective by Altmann <jats:italic>et al.</jats:italic> ). Serum was derived from 40 subjects in two age groups 21 days after the booster shot. The vaccine remained effective against B.1.1.7 with a slight but significant decrease in neutralization that was more apparent in participants under 55 years of age. Thus, the vaccine provides a significant “cushion” of protection against this variant. </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="6534" page="1152" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg6105">1152</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6534" page="1103" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg7404">1103</jats:related-article> </jats:p>

<jats:title>Fungal aggravation</jats:title> <jats:p> The gut microbiota includes not only prokaryotes, viruses, protists, and occasionally helminths, but also fungi. The role that fungi play in this symbiosis has long been overlooked. While investigating alterations to the gut microbiota in mice with mucosal damage and human subjects with Crohn's disease, Jain <jats:italic>et al.</jats:italic> discovered the fungus <jats:italic>Debaryomyces hansenii</jats:italic> localized to wounds in inflamed mucosal tissue (see the Perspective by Chiaro and Round). Impaired healing was associated with antibiotic treatment, overgrowth of the fungus, and subsequent induction of a type I interferon–CCL5 axis by macrophages. The fungus was observed within macrophages. Such persistent injury stimulus is a hallmark of inflammatory bowel diseases, including Crohn's disease and ulcerative colitis. It is not known whether this salt-tolerant fungus is a natural symbiont, but it is used in the food industry for surface ripening of cheese and meat products. </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="6534" page="1154" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abd0919">1154</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6534" page="1102" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg6017">1102</jats:related-article> </jats:p>

<jats:title>Change of flow</jats:title> <jats:p> Anthropogenic influence on climate has changed temperatures, precipitation, atmospheric circulation, and many other related physical processes, but has it changed river flow as well? Gudmundsson <jats:italic>et al.</jats:italic> analyzed thousands of time series of river flows and hydrological extremes across the globe and compared them with model simulations of the terrestrial water cycle (see the Perspective by Hall and Perdigão). They found that the observed trends can only be explained if the effects of climate change are included. Their analysis shows that human influence on climate has affected the magnitude of low, mean, and high river flows on a global scale. </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="6534" page="1159" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.aba3996">1159</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6534" page="1096" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg6514">1096</jats:related-article> </jats:p>

<jats:title>A supersolid rotation</jats:title> <jats:p> When a bucket of water is rotated, the water rotates with the vessel, contributing to the total moment of inertia. If such an experiment were done with a superfluid, it would decouple from the vessel and would not contribute to rotation. Tanzi <jats:italic>et al.</jats:italic> studied an intermediate case, a supersolid, which is predicted to only partially decouple, resulting in a moment of inertia smaller than the classical value. Whereas previous such experiments were done with helium, the authors used a gas of highly magnetic dysprosium atoms in an optical trapping potential that was suddenly changed, causing the gas to oscillate. Measuring the frequency of these oscillations provides evidence for a reduced moment of inertia. </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="6534" page="1162" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.aba4309">1162</jats:related-article> </jats:p>

<jats:title>Designing smarter anticancer T cells</jats:title> <jats:p> Biological signaling systems can exhibit a large, nonlinear—or “ultrasensitive”—response, which would be useful to engineer into therapeutic T cells to allow for better discrimination between cancer cells and normal tissues. Hernandez-Lopez <jats:italic>et al.</jats:italic> modified human T cells using a two-step mechanism that allowed them to kill cells expressing large amounts of cancer marker protein but not cells expressing a small amount of the same protein. A first synthetic receptor recognized the antigen with low affinity. That receptor signaled to increase expression of a chimeric antigen receptor (CAR) with high affinity for the same antigen. The circuit proved effective in cell culture and mouse cancer models, offering hope of extending the CAR T cell strategy against solid tumors. </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="6534" page="1166" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abc1855">1166</jats:related-article> </jats:p>