Catálogo de publicaciones - revistas

<jats:title>Making metallic ribbons</jats:title> <jats:p> In its usual two-dimensional form, graphene does not have an energy gap in its electronic structure. However, one-dimensional ribbons made of the material are semiconducting and making them metallic is tricky. Rizzo <jats:italic>et al.</jats:italic> developed a strategy for synthesizing metallic graphene nanoribbons and demonstrated their metallicity using scanning tunneling spectroscopy. These metallic graphene nanoribbons may be useful for exploring exotic quantum phases in a single dimension. </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="6511" page="1597" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aay3588">1597</jats:related-article> </jats:p>

<jats:title>Modeling SARS-CoV-2 in mice</jats:title> <jats:p> Among the research tools necessary to develop medical interventions to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, high on the list are informative animal models with which to study viral pathogenesis. Gu <jats:italic>et al.</jats:italic> developed a mouse model in which a SARS-CoV-2 strain was infectious and could cause an inflammatory response and moderate pneumonia. Adaptation of this viral strain in the mouse appeared to be dependent on a critical amino acid change, Asn <jats:sup>501</jats:sup> to Tyr (N501Y), within the receptor-binding domain of the viral spike protein. The new mouse model was used to study neutralizing antibodies and a vaccine candidate against the virus. </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="6511" page="1603" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc4730">1603</jats:related-article> </jats:p>

<jats:title>Reconfiguring an immune response</jats:title> <jats:p> The deep sea is a vast and generally empty environment. Finding a mate can thus be difficult. In response to this situation, one group of deep-sea denizens, the anglerfishes, have evolved a system in which males attach to females, in some cases permanently, through fusion of tissues and connection of circulatory systems. Such attachment greatly challenges the immune systems of the fish. Swann <jats:italic>et al.</jats:italic> found that these challenges have been met by the evolution of increasingly reduced immune responses among anglerfish species, including the loss of what have been considered essential vertebrate responses. These shifts suggest that vertebrate immune systems may be more flexible over evolutionary time than was previously thought. </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="6511" page="1608" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz9445">1608</jats:related-article> </jats:p>

<jats:title>Operating in wet conditions</jats:title> <jats:p> The high efficiency of the complex organic molecule Spiro-OMeTAD as a hole-transporting material for perovskite solar cells requires the use of hygroscopic dopants that decrease stability. Jeong <jats:italic>et al.</jats:italic> synthesized hydrophobic fluorinated analogs of Spiro-OMeTAD as hole-transporting materials that have favorable shifting of the electronic state for hole extraction and used them to fabricate perovskite solar cells. A champion device had a certified power conversion efficiency of 24.8% and an open-circuit voltage near the Shockley-Queisser limit. These devices could maintain more than 87% of the original power conversion efficiency under 50% relative humidity for more than 500 hours. </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="6511" page="1615" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb7167">1615</jats:related-article> </jats:p>

<jats:title>The heat is on</jats:title> <jats:p> Anthropogenic climate change is causing not only more episodes of historically high air temperatures but also more frequent spells of unusually increased ocean temperatures. Marine heatwaves, defined as periods of anomalously high regional surface ocean temperatures, have also become common in recent decades. Laufkötter <jats:italic>et al.</jats:italic> show that the frequency of these events has already increased more than 20-fold because of anthropogenic global warming, making marine heatwaves, which typically occurred once in hundreds to thousands of years in preindustrial times, likely to occur on an annual to decadal basis if the global average air temperature rises by 3°C. </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="6511" page="1621" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba0690">1621</jats:related-article> </jats:p>

<jats:title>Consciousness shared</jats:title> <jats:p> Humans have tended to believe that we are the only species to possess certain traits, behaviors, or abilities, especially with regard to cognition. Occasionally, we extend such traits to primates or other mammals—species with which we share fundamental brain similarities. Over time, more and more of these supposed pillars of human exceptionalism have fallen. Nieder <jats:italic>et al.</jats:italic> now argue that the relationship between consciousness and a standard cerebral cortex is another fallen pillar (see the Perspective by Herculano-Houzel). Specifically, carrion crows show a neuronal response in the palliative end brain during the performance of a task that correlates with their perception of a stimulus. Such activity might be a broad marker for consciousness. </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="6511" page="1626" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb1447">1626</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6511" page="1567" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abe0536">1567</jats:related-article> </jats:p>

<jats:title>Nonlinear x-ray spectroscopy</jats:title> <jats:p> The extension of nonlinear optics to the x-ray spectral domain is a promising direction in the development of x-ray spectroscopy. Although theoretical concepts of nonlinear x-ray spectroscopy were developed decades ago, scientists still struggle to implement them because of the elusive nature of nonlinear effects. Eichmann <jats:italic>et al.</jats:italic> now present atomic momentum spectroscopy (AMS), which is based on the detection of the scattered atom after momentum transfer from x-ray photons (see the Perspective by Pfeifer). The authors show how AMS can observe stimulated x-ray Raman scattering signals at the neon K edge on a single-atom level and distinguish them from other competing processes. These results pave the way for future nonlinear x-ray spectroscopy methods for the study of x-ray–matter interactions. </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="6511" page="1630" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc2622">1630</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6511" page="1568" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd6168">1568</jats:related-article> </jats:p>

<jats:title>Fumarate targets pyroptosis</jats:title> <jats:p> A form of inflammatory cell death called pyroptosis depends on the caspase-mediated cleavage of gasdermin D (GSDMD), the fragments of which assemble into permeability pores that then kill the cell. The mechanisms regulating this important cellular process are not yet fully understood. Humphries <jats:italic>et al.</jats:italic> now report that the tricarboxylic acid cycle intermediate fumarate can act as an inhibitor of pyroptosis (see the Perspective by Pickering and Bryant). Both endogenous fumarate and exogenously delivered dimethyl fumarate (DMF) convert the cysteines in GSDMD to S-(2-succinyl)-cysteines (a process called succination) to prevent its interaction with caspases and subsequent processing and activation. Administration of DMF to mice alleviated inflammation in models of multiple sclerosis and familial Mediterranean fever. These findings may explain the efficacy of DMF as a treatment for multiple sclerosis and other inflammatory diseases and offer insights into future anti-inflammatory 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="6511" page="1633" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb9818">1633</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6511" page="1564" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abe0917">1564</jats:related-article> </jats:p>

<jats:title>Logic at the cell surface</jats:title> <jats:p> A major challenge in medical interventions is to target only diseased cells. Although there are biomarkers characteristic of certain cancers, for example, it is unlikely that a single marker can specify a particular cell type. Lajoie <jats:italic>et al.</jats:italic> addressed this problem by designing protein switches called Co-LOCKR that bind to antigens on the cell surface and activate through a conformational change only when there is a precise combination of antigens. They designed switches that can perform AND, OR, and NOT logic. On the path toward applying this technology, they used Co-LOCKR to direct chimeric antigen receptor T cells to tumor cells expressing specific antigens. </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="6511" page="1637" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba6527">1637</jats:related-article> </jats:p>

<jats:title>Schistosome biology illuminated</jats:title> <jats:p> Schistosomiasis is caused by a parasitic flatworm about which little is known. Therefore, options to combat human disease caused by schistosome infection are limited. To aid in our quest to develop treatments, two studies undertook molecular investigations of the parasite <jats:italic>Schistosoma mansoni</jats:italic> . By generating a single-cell atlas, Wendt <jats:italic>et al.</jats:italic> identified the developmental trajectory of the flatworm, including the blood-feeding gut required for its survival in the host. From these data, they found a gene required for gut development that, when knocked out through RNA interference, confers reduced pathology in infected mice. Wang <jats:italic>et al.</jats:italic> performed a large-scale RNA interference survey of <jats:italic>S. mansoni</jats:italic> and identified an essential pair of protein kinases that can be targeted by approved pharmacological intervention (see the Perspective by Anderson and Duraisingh). These molecular investigations add to our understanding of the schistosome parasite and provide biological information that may help to combat this neglected tropical disease. </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="6511" page="1644" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb7709">1644</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6511" page="1649" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb7699">1649</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6511" page="1562" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abe0710">1562</jats:related-article> </jats:p>