Catálogo de publicaciones - revistas

<jats:p>An ancient archive offers new insights into the construction of a man-made wonder</jats:p>

<jats:p>A wry romp through science’s greatest hits and challenges entertains and illuminates</jats:p>

<jats:p> Highlights from the <jats:italic>Science</jats:italic> family of journals </jats:p>

<jats:p>Editors’ selections from the current scientific literature</jats:p>

<jats:title>Antibody levels predict vaccine efficacy</jats:title> <jats:p> Symptomatic COVID-19 infection can be prevented by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines. A “correlate of protection” is a molecular biomarker to measure how much immunity is needed to fight infection and is key for successful global immunization programs. Gilbert <jats:italic>et al</jats:italic> . determined that antibodies are the correlate of protection in vaccinated individuals enrolled in the Moderna COVE phase 3 clinical trial (see the Perspective by Openshaw). By measuring binding and neutralizing antibodies against the viral spike protein, the authors found that the levels of both antibodies correlated with the degree of vaccine efficacy. The higher the antibody level, the greater the protection afforded by the messenger RNA (mRNA) vaccine. Antibody levels that predict mRNA vaccine efficacy can therefore be used to guide vaccine regimen modifications and support regulatory approvals for a broader spectrum of the population. —PNK </jats:p>

<jats:title>Intron recognition in the spotlight</jats:title> <jats:p> Excision of noncoding introns from pre–messenger RNAs is catalyzed by the spliceosome, a large RNA-protein complex that recognizes specific sequences at the exon-intron boundaries (splice sites). These sequences are highly degenerate in humans, and it has remained elusive how they are recognized by the spliceosome. Tholen <jats:italic>et al</jats:italic> . report a series of high-resolution structures of the human U2 small nucleolar ribonucleoprotein, the component of the spliceosome that recognizes branch sites. The structures explain how SF3B6 helps to stabilize the branch helix in the absence of extensive sequence complementarity. A newly identified spliceosome assembly intermediate suggests a mechanism for fidelity control of branch site recognition. —DJ </jats:p>

<jats:title>Hotspot cool down</jats:title> <jats:p> Deep-seated mantle plumes are responsible for volcanic island chains such as Hawai’i. Upwelling from the deep interior requires that the plumes are hotter than the surrounding mantle to make it all the way up to the surface. However, Bao <jats:italic>et al</jats:italic> . found that some of these “hotspots” are surprisingly cool. The temperature is actually low enough to challenge a deep mantle origin for some hotspots. In these specific cases, deep plumes may be entrained and cooled or possibly originate in the upper mantle instead. —BG </jats:p>

<jats:title>Zeolitic nanotubes</jats:title> <jats:p> Nanotubes generally have solid walls, but a low-dimensional version of zeolites now introduces porosity into such structures. Korde <jats:italic>et al</jats:italic> . used a structure-directing agent with a hydrophobic biphenyl group center connecting two long alkyl chains bearing hydrophilic bulky quaternary ammonium head groups to direct hydrothermal synthesis with silicon-rich precursors (see the Perspective by Fan and Dong). The nanotubes have a mesoporous central channel of approximately 3 nanometers and zeolitic walls with micropores less than 0.6 nanometers. Electron microscopy and modeling showed that the outer surface is a projection of a large-pore zeolite and the inner surface is a projection of a medium-pore zeolite. —PDS </jats:p>

<jats:title>Preservation of cycling behavior</jats:title> <jats:p> Understanding the changes in interfaces between electrode and electrolyte during battery cycling, including the formation of the solid-electrolyte interphase (SEI), is key to the development of longer lasting batteries. Z. Zhang <jats:italic>et al</jats:italic> . adapt a thin-film vitrification method to ensure the preservation of liquid electrolyte so that the samples taken for analysis using microscopy and spectroscopy better reflect the state of the battery during operation. A key finding is that the SEI is in a swollen state, in contrast to current belief that it only contained solid inorganic species and polymers. The extent of swelling can affect transport through the SEI, which thickens with time, and thus might also decrease the amount of free electrolyte available for battery cycling. —MSL </jats:p>

<jats:title>Directing efficient hole transport</jats:title> <jats:p> Surface defects in three-dimensional perovskites can decrease performance but can be healed with coatings based on two-dimensional (2D) perovskite such as Ruddlesden-Popper phases. However, the bulky organic groups of these 2D phases can lead to low and anisotropic charge transport. F. Zhang <jats:italic>et al</jats:italic> . show that a metastable polymorph of a Dion-Jacobson 2D structure based on asymmetric organic molecules reduced the energy barrier for hole transport and their transport through the layer. When used as a top layer for a triple-cation mixed-halide perovskite, a solar cell retained 90% of its initial power conversion efficiency of 24.7% after 1000 hours of operation at approximately 40°C in nitrogen. —PDS </jats:p>