Catálogo de publicaciones - revistas

<jats:title>Locking in nanoscale strength</jats:title> <jats:p> Metals with nanometer-sized crystal grains are super strong, but they do not generally retain their structure at higher temperatures. This property undermines their high strength and makes their use in applications challenging. Li <jats:italic>et al.</jats:italic> found a minimum-interface structure in copper with 10-nanometer-sized grains that, when combined with a nanograin crystallographic twinning network, retains high strength to temperatures just below the melting point. This discovery suggests a different path forward for stabilizing nanograined metals. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6518" page="831" related-article-type="in-this-issue" vol="370">831</jats:related-article> </jats:p>

<jats:title>Timing Solar System formation</jats:title> <jats:p> The oldest solids that formed in the Solar System are calcium-aluminium–rich inclusions (CAIs), small metallic droplets that were later incorporated into meteorites. The ages of CAIs are conventionally taken as the age of the Solar System, but which exact moment in star formation they correspond to has been unclear. Brennecka <jats:italic>et al.</jats:italic> measured molybdenum isotope ratios in CAIs and found a wide range of origins in both the inner and outer Solar System. They propose that CAIs formed from heterogeneous material accreting from the presolar nebula and that the ages of CAIs coincide with the Sun's transition from a protostar to a pre–main sequence star. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6518" page="837" related-article-type="in-this-issue" vol="370">837</jats:related-article> </jats:p>

<jats:title>Getting phonons to hang around</jats:title> <jats:p> The ideal platform for quantum-computing and quantum-sensing applications is likely to be a hybrid system that combines the best features of different components. Superconducting circuits are relatively advanced, and finding components that can control and manipulate the microwaves will be essential. MacCabe <jats:italic>et al.</jats:italic> explored the use of high-quality microresonators in which the acoustic environment could be engineered such that the phonon lifetime could be extended to more than 1 second. Operating at microwave frequencies of 5 gigahertz, these quantum acoustic-dynamic devices could be coupled with superconducting circuits. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6518" page="840" related-article-type="in-this-issue" vol="370">840</jats:related-article> </jats:p>

<jats:title>Higher-order thalamus input to the cortex</jats:title> <jats:p> Sensory information can only be used meaningfully in the brain when integrated with and compared with internally generated top-down signals. However, we know little about the brainwide afferents that convey such top-down signals, their information content, and learning-related plasticity. Pardi <jats:italic>et al.</jats:italic> identified the higher-order thalamus as a major source of top-down input to mouse auditory cortex and investigated a circuit in cortical layer 1 that facilitates plastic changes and flexible responses. These results demonstrate how top-down feedback information can reach cortical areas through a noncortical structure that has received little attention despite its widespread connections with the cortex. </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="6518" page="844" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abc2399">844</jats:related-article> </jats:p>

<jats:title>Colorful changes</jats:title> <jats:p> Distributed fiber-optic sensors have been used for monitoring mechanical deformations in stiff infrastructures such as bridges, roads, and buildings, but they either are limited to measuring one variable or require complex optics to measure multiple properties. Bai <jats:italic>et al.</jats:italic> now demonstrate dual-core elastomeric optical fibers, one of which contains patterned dye regions. The waveguides are fabricated by molding out of commercially available elastomers and integrate a clear core and an adjacent core doped with up to three macroscale dye regions. Changes in optical paths in the two cores detect deformation and map it onto a color space. By monitoring changes in the color and intensity in both elastomer-based fibers, the researchers could distinguish bending, stretching, and localized pressing with a spatial resolution down to ∼1 centimeter. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6518" page="848" related-article-type="in-this-issue" vol="370">848</jats:related-article> </jats:p>

<jats:title>Cellular adaptation during metabolic stress</jats:title> <jats:p> Cells respond to environmental stress by down-regulating general protein synthesis and inducing selective expression of proteins required for survival. However, the mechanisms controlling this selective messenger RNA (mRNA) translation response remain poorly understood. Lamper <jats:italic>et al.</jats:italic> report that the noncanonical 5′ cap-binding protein subunit eIF3d is activated upon metabolic stress in mammalian cells to reprogram cellular mRNA translation. eIF3d is activated by a switch in phosphorylation status at sites near the cap-binding pocket and enables cells to express the proteins required for the regulation of metabolism and survival during stresses, including glucose starvation. This work reveals how eIF3d-dependent, noncanonical cap-dependent translation controls the cellular adaptation to stress. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6518" page="853" related-article-type="in-this-issue" vol="370">853</jats:related-article> </jats:p>

<jats:title>Another host factor for SARS-CoV-2</jats:title> <jats:p> Virus-host interactions determine cellular entry and spreading in tissues. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the earlier SARS-CoV use angiotensin-converting enzyme 2 (ACE2) as a receptor; however, their tissue tropism differs, raising the possibility that additional host factors are involved. The spike protein of SARS-CoV-2 contains a cleavage site for the protease furin that is absent from SARS-CoV (see the Perspective by Kielian). Cantuti-Castelvetri <jats:italic>et al.</jats:italic> now show that neuropilin-1 (NRP1), which is known to bind furin-cleaved substrates, potentiates SARS-CoV-2 infectivity. NRP1 is abundantly expressed in the respiratory and olfactory epithelium, with highest expression in endothelial and epithelial cells. Daly <jats:italic>et al.</jats:italic> found that the furin-cleaved S1 fragment of the spike protein binds directly to cell surface NRP1 and blocking this interaction with a small-molecule inhibitor or monoclonal antibodies reduced viral infection in cell culture. Understanding the role of NRP1 in SARS-CoV-2 infection may suggest potential targets for future antiviral therapeutics. </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="6518" page="856" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd2985">856</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6518" page="861" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd3072">861</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6518" page="765" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abf0732">765</jats:related-article> </jats:p>

<jats:title>Another host factor for SARS-CoV-2</jats:title> <jats:p> Virus-host interactions determine cellular entry and spreading in tissues. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the earlier SARS-CoV use angiotensin-converting enzyme 2 (ACE2) as a receptor; however, their tissue tropism differs, raising the possibility that additional host factors are involved. The spike protein of SARS-CoV-2 contains a cleavage site for the protease furin that is absent from SARS-CoV (see the Perspective by Kielian). Cantuti-Castelvetri <jats:italic>et al.</jats:italic> now show that neuropilin-1 (NRP1), which is known to bind furin-cleaved substrates, potentiates SARS-CoV-2 infectivity. NRP1 is abundantly expressed in the respiratory and olfactory epithelium, with highest expression in endothelial and epithelial cells. Daly <jats:italic>et al.</jats:italic> found that the furin-cleaved S1 fragment of the spike protein binds directly to cell surface NRP1 and blocking this interaction with a small-molecule inhibitor or monoclonal antibodies reduced viral infection in cell culture. Understanding the role of NRP1 in SARS-CoV-2 infection may suggest potential targets for future antiviral therapeutics. </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="6518" page="856" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd2985">856</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6518" page="861" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd3072">861</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6518" page="765" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abf0732">765</jats:related-article> </jats:p>

<jats:title>Cysteine as peptide precursor and catalyst</jats:title> <jats:p> Among amino acids, cysteine is highly reactive as a nucleophile, metal ligand, and participant in redox and radical reactions. These properties make cysteine attractive as a component of prebiotic chemistry, but traditional Strecker synthesis of α-aminonitriles, which can serve as peptide precursors, cannot produce free cysteine. Foden <jats:italic>et al.</jats:italic> found that a simple acylation of the free amine prevented degradation of cysteine nitrile and enabled synthesis of this cysteine precursor from acetyl dehydroalanine nitrile and a sulfide donor (see the Perspective by Muchowska and Moran). When combined with other proteinogenic α-aminonitriles, acetylcysteine or derivative thiols catalyzed efficient peptide ligation in water. These results highlight how prebiotic synthesis of precursors can also generate function by creating a catalyst for polymerization. </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="6518" page="865" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd5680">865</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6518" page="767" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abf1698">767</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>