Catálogo de publicaciones - revistas

<jats:title>Engineering phosphorous anodes</jats:title> <jats:p> A focus of battery research has been the development of a range of lithium, sodium, and potassium cathodes, but improving anode materials is also an important goal. Silicon has shown some promise for replacing graphite because of its exceptional capacity, but the dramatic volume change during lithiation-delithiation processes often leads to failure. Jin <jats:italic>et al.</jats:italic> developed a composite that is made of black phosphorous and graphite in its core and covered with swollen polyaniline. In contrast to previous efforts, bonding between the carbon and phosphorous allows for a high charging rate without sacrifices in capacity and cycling stability. </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="6513" page="192" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.aav5842">192</jats:related-article> </jats:p>

<jats:title>Spacetime, reconstructed</jats:title> <jats:p>Theories of holographic duality feature a correspondence between a gravitational system and a strongly interacting conformal field theory (CFT) living on the system's boundary. Through this correspondence, the CFT encodes the geometry of spacetime in the gravitational system. Van Raamsdonk analyzed the role of entanglement in this theoretical framework. Instead of considering a single CFT, the author's starting point was a collection of CFT “bits” that are mutually entangled but do not interact with one another. The spacetime that these bits collectively encode was then shown to be arbitrarily close to the one encoded by the original CFT, suggesting that entanglement plays a crucial role in the emergence of spacetime.</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="6513" page="198" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.aay9560">198</jats:related-article> </jats:p>

<jats:title>Flexible spikes</jats:title> <jats:p> The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein enables viral entry into host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor and is a major target for neutralizing antibodies. About 20 to 40 spikes decorate the surface of virions. Turoňová <jats:italic>et al.</jats:italic> now show that the spike is flexibly connected to the viral surface by three hinges that are well protected by glycosylation sites. The flexibility imparted by these hinges may explain how multiple spikes act in concert to engage onto the flat surface of a host cell. </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="6513" page="203" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd5223">203</jats:related-article> </jats:p>

<jats:title>Intersexuality in female moles</jats:title> <jats:p> Female moles are intersexual and develop masculinizing ovotestes, a distinctive trait among mammals. Real <jats:italic>et al.</jats:italic> investigated the origin of this trait by sequencing the Iberian mole genome and applying comparative strategies that integrate transcriptomic, epigenetic, and chromatin interaction data. They identified mole-specific genomic rearrangements that alter the three-dimensional regulatory landscape of the androgen-converting gene <jats:italic>CYP17A1</jats:italic> and the pro-testicular factor gene <jats:italic>FGF9</jats:italic> , both of which show distinct expression patterns in mole gonads. The use of transgenic mice confirms the capability of these factors to increase circulating testosterone levels and to induce gonadal masculinization. This study highlights how integrative approaches can reveal the phenotypic impact of genomic variation. </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="6513" page="208" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.aaz2582">208</jats:related-article> </jats:p>

<jats:title>A potential method to tune reactivity</jats:title> <jats:p> In organic chemistry, reaction rates are often sensitive to substituents that either donate or withdraw electron density from a reactive carbon center. Heo <jats:italic>et al.</jats:italic> now report that when reactants are tethered to an electrode, the polarization effect of an applied potential can exert an analogous influence, essentially acting as a tunable functional group. The authors demonstrate rate modulations in ester hydrolysis and arene cross-coupling, as well as a two-step acid-to-amide conversion that benefits from inversion of the polarization midway through the reaction. </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="6513" page="214" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abb6375">214</jats:related-article> </jats:p>

<jats:title>Change begets change</jats:title> <jats:p> In the Anthropocene, humans are altering ecosystems, causing extinctions, and reassorting species distributions. As we facilitate these changes, we are creating new collections of species. Such “novel communities” are not specific to our epoch, and the patterns of diversity and extinction associated with past events can shed light on the implications of current community restructuring. Pandolfi <jats:italic>et al.</jats:italic> looked at marine plankton communities over the past ∼66 million years and found that the emergence of novel communities leads to further novelty and extinction (see the Perspective by Dornelas and Madin). Although community change is a natural biological response to environmental change, the current rate of change could lead to impending and rapid impacts. </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="6513" page="220" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abb3996">220</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6513" page="164" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe4727">164</jats:related-article> </jats:p>

<jats:title>Going for the gold</jats:title> <jats:p> Single-particle cryogenic electron microscopy (cryo-EM) has become a go-to technique for structural biologists. Although data-processing and reconstruction methods have improved, innovations in sample preparation and data collection are essential to reliably achieve high-resolution reconstructions while also reducing the amount of time required per structure. Naydenova <jats:italic>et al.</jats:italic> tackled the issue of electron beam–induced particle movement, a major source of information loss, by designing a gold sample support that prevents buckling of the extremely thin layer of ice in which the particles are suspended (see Perspective by Rapp and Carragher). The negligible particle displacement permits extrapolation to “zero exposure” structure factors, revealing features typically lost in cryo-EM structures. Far fewer particles per unit resolution are required, which greatly accelerates structure determination, especially at high resolution. </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="6513" page="223" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abb7927">223</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6513" page="171" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd8035">171</jats:related-article> </jats:p>

<jats:title>Building a safe space for stem cells</jats:title> <jats:p> The meristem, the collection of stem cells that builds plants, is resistant to viral infection. Wu <jats:italic>et al.</jats:italic> now show that WUSCHEL, a transcription factor that helps to sustain stem cell production in the shoot apical meristem of <jats:italic>Arabidopsis</jats:italic> , also protects that stem cell domain from viruses. WUSCHEL inhibited viral protein synthesis by repressing methyltransferases that regulate ribosomal RNA processing and ribosome stability. </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="6513" page="227" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abb7360">227</jats:related-article> </jats:p>