Catálogo de publicaciones - revistas

<jats:title>Making dilute quantum droplets</jats:title> <jats:p> In recent years, quantum fluids have been studied largely in gaseous form, such as the Bose-Einstein condensates (BECs) of alkali atoms and related species. Quantum liquids, other than liquid helium, have been comparatively more difficult to come by. Cabrera <jats:italic>et al.</jats:italic> combined two BECs and manipulated the atomic interactions to create droplets of a quantum liquid (see the Perspective by Ferrier-Barbut and Pfau). Because the interactions were not directional, the droplets had a roughly round shape. The simplicity of this dilute system makes it amenable to theoretical modeling, enabling a better understanding of quantum fluids. </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="6373" page="301" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao5686">301</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6373" page="274" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aar3785">274</jats:related-article> </jats:p>

<jats:title>Seismicity curbed by lowering volume</jats:title> <jats:p> Determining why hydraulic fracturing (also known as fracking) triggered earthquakes in the Duvernay Formation in Canada is important for future hazard mitigation. Schultz <jats:italic>et al.</jats:italic> found that injection volume was the key operational parameter correlated with induced earthquakes in the Duvernay. However, geological factors also played a considerable role in determining whether a large injection volume would trigger earthquakes. These findings provide a framework that may lead to better forecasting of induced seismicity. </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="6373" page="304" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao0159">304</jats:related-article> </jats:p>

<jats:title>Boosting chiral nanoparticle responses</jats:title> <jats:p> Optical nanomaterials that combine chirality and magnetism are useful for magneto-optics and as chiral catalysts. Although chiral inorganic nanostructures can exhibit high circular dichroism, modulating this optical activity has usually required irreversible chemical changes. Yeom <jats:italic>et al.</jats:italic> synthesized paramagnetic cobalt oxide (Co <jats:sub>3</jats:sub> O <jats:sub>4</jats:sub> ) nanoparticles with <jats:sc>l</jats:sc> - and <jats:sc>d</jats:sc> -cysteine surface ligands. These ligands created chiral distortions of the crystal lattices, and this anisotropy led to much stronger chiroptical activity. The circular dichroism in the ultraviolet of nanoparticle gels could be modulated with magnetic fields of ∼1.5 tesla. </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="6373" page="309" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao7172">309</jats:related-article> </jats:p>

<jats:title>A plastic plan for organic synthesis</jats:title> <jats:p> The infrastructure for chemical synthesis typically lies at either end of a spectrum: small-scale studies in ad hoc assemblies of glassware or large-scale production in capital-intensive custom reactors. Kitson <jats:italic>et al.</jats:italic> report a hybrid protocol that customizes a blueprint for synthesis of a target compound in a series of interconnected plastic modules, which can be assembled en masse by 3D printing (see the Perspective by Hornung). The approach, demonstrated for the commercial muscle relaxant baclofen, establishes a systematic workflow that is potentially amenable to automation: All that is necessary for synthesis and purification is the introduction of stock solutions and variation of temperature or pressure. </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="6373" page="314" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao3466">314</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6373" page="273" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aar4543">273</jats:related-article> </jats:p>

<jats:title>A global map of soil bacteria</jats:title> <jats:p> Soil bacteria play key roles in regulating terrestrial carbon dynamics, nutrient cycles, and plant productivity. However, the natural histories and distributions of these organisms remain largely undocumented. Delgado-Baquerizo <jats:italic>et al.</jats:italic> provide a survey of the dominant bacterial taxa found around the world. In soil collections from six continents, they found that only 2% of bacterial taxa account for nearly half of the soil bacterial communities across the globe. These dominant taxa could be clustered into ecological groups of co-occurring bacteria that share habitat preferences. The findings will allow for a more predictive understanding of soil bacterial diversity and distribution. </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="6373" page="320" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aap9516">320</jats:related-article> </jats:p>

<jats:title>Data-driven refugee assignment</jats:title> <jats:p> The continuing refugee crisis has made it necessary for governments to find ways to resettle individuals and families in host communities. Bansak <jats:italic>et al.</jats:italic> used a machine learning approach to develop an algorithm for geographically placing refugees to optimize their overall employment rate. The authors developed and tested the algorithm on segments of registry data from the United States and Switzerland. The algorithm improved the employment prospects of refugees in the United States by ∼40% and in Switzerland by ∼75%. </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="6373" page="325" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao4408">325</jats:related-article> </jats:p>

<jats:title>Substrate recognition by Dicer elucidated</jats:title> <jats:p> The Dicer protein generates short RNAs from double-stranded RNA (dsRNA) substrates and is critical for RNA interference and antiviral defense. Sinha <jats:italic>et al.</jats:italic> report structures of a <jats:italic>Drosophila</jats:italic> Dicer protein that shed light on its two distinct mechanisms for recognizing and cleaving substrates: adenosine triphosphate (ATP)-independent, distributive cleavage of 3′-overhang dsRNAs and ATP-dependent, processive threading of blunt-end dsRNAs. This flexibility might provide invertebrates with the optimization capabilities needed for antiviral defense. </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="6373" page="329" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aaq0921">329</jats:related-article> </jats:p>

<jats:title>A naturally modified cellulose</jats:title> <jats:p> Cellulose is the most abundant biopolymer on Earth and an important component of bacterial biofilms. Thongsomboon <jats:italic>et al.</jats:italic> used solid-state nuclear magnetic resonance spectroscopy to identify a naturally derived, chemically modified cellulose, phosphoethanolamine cellulose (see the Perspective by Galperin and Shalaeva). They went on to identify the genetic basis and molecular signaling involved in introducing this modification in bacteria, which regulates biofilm matrix architecture and function. This discovery has implications for understanding bacterial biofilms and for the generation of new cellulosic materials. </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="6373" page="334" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao4096">334</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6373" page="276" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aar5253">276</jats:related-article> </jats:p>

<jats:title>Recognizing centromere by kinetochore</jats:title> <jats:p> The kinetochore proteins CENP-N and CENP-C recognize the histone H3 variant CENP-A in the centromeric nucleosome. This ensures proper kinetochore assembly and accurate segregation of chromosomes. Chittori <jats:italic>et al.</jats:italic> describe the cryo-electron microscopy structure of the human CENP-A nucleosome-CENP-N complex. The interaction of CENP-N with CENP-A and the nucleosomal DNA together ensure specific and stable centromeric nucleosome recognition. Mutational analyses using both human and <jats:italic>Xenopus</jats:italic> CENP-A and CENP-N proteins suggest that the proteins have coevolved to preserve the interacting surfaces. </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="6373" page="339" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aar2781">339</jats:related-article> </jats:p>

<jats:title>Large-scale gene synthesis in tiny droplets</jats:title> <jats:p> Gene synthesis technology is important for functional characterization of DNA sequences and for the development of synthetic biology. However, current methods are limited by their low scalability and high cost. Plesa <jats:italic>et al.</jats:italic> developed a gene synthesis method, DropSynth, which uses barcoded beads to concentrate oligos and subsequently assemble them into synthetic genes within picoliter emulsion droplets. DropSynth allows generation of large libraries of thousands of genes and functional testing of all possible mutations of a particular sequence. </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="6373" page="343" related-article-type="in-this-issue" vol="359" xlink:href="10.1126/science.aao5167">343</jats:related-article> </jats:p>