Catálogo de publicaciones - revistas

<jats:title>A nanostructure quantum simulator</jats:title><jats:p>Phase transitions occurring at absolute zero temperature, or quantum phase transitions (QPTs), can be grouped into broad categories called universality classes. The classification is based on the properties of the transition rather than the microscopic details of the underlying system. Iftikhar<jats:italic>et al.</jats:italic>exploited this fact to study QPTs in clean, tunable nanostructures, rather than in complex materials, where they most often occur. Within a single nanostructure, two different classes of QPTs with profoundly different characters were studied and comprehensively characterized.</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="6395" page="1315" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aan5592">1315</jats:related-article></jats:p>

<jats:title>Finding the vulnerable minority</jats:title> <jats:p> “Only” about 10 to 15% of people exposed to alcohol develop alcohol-related problems. The behavioral repertoire of people confronted with opportunities to consume alcohol involves numerous choices between this drug reward and healthy alternatives. Augier <jats:italic>et al.</jats:italic> established a choice procedure that begins to address alcohol addiction in rats (see the Perspective by Spanagel). They found that a minority of outbred rats continued to self-administer alcohol even when a high-value alternative (such as sugar) was available. That minority displayed a remarkable constellation of behavioral traits resembling the human clinical condition, including a high motivation to obtain alcohol and continued use despite adverse consequences. The cause was impaired GABA (γ-aminobutyric acid) clearance in the central amygdala. Postmortem tissue analysis supported the possibility of a similar pathology in human alcoholism. </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="6395" page="1321" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aao1157">1321</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6395" page="1298" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aau0668">1298</jats:related-article> </jats:p>

<jats:title>Time and place of electron exit</jats:title> <jats:p> Until about a decade ago, laser-induced ionization was considered instantaneous. Since then, applications of attosecond laser pulses have shown multiple subtle and complex factors that influence the precise timing of electron ejection from atoms and surfaces. Vos <jats:italic>et al.</jats:italic> measured the corresponding attosecond dynamics of dissociative photoionization in a diatomic molecule, carbon monoxide. By imaging the charged fragments, the timing could be correlated with the specific spatial portion of the molecule from which the electron wave packet emerged. </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="6395" page="1326" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aao4731">1326</jats:related-article> </jats:p>

<jats:title>Taking enantiomers for a spin</jats:title> <jats:p> There are two common ways to distinguish mirror-image molecules, or enantiomers. The first relies on their distinct interactions with circularly polarized light, the second on their interactions with a pure enantiomer of some other molecule. Now Banerjee-Ghosh <jats:italic>et al.</jats:italic> report a conceptually different approach to chiral resolution. Experiments showed that, depending on the direction of magnetization, chiral oligopeptides, oligonucleotides, and amino acids have enantiospecific differences in initial adsorption rates on ferromagnetic surfaces. This effect is attributed to enantiospecific induced spin polarization. </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="6395" page="1331" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aar4265">1331</jats:related-article> </jats:p>

<jats:title>A quick rebound for Antarctic crust</jats:title> <jats:p> Earth's crust deforms under the load of glaciers and ice sheets. When these masses are removed, the crust rebounds at a time scale determined by the viscosity of the upper mantle. Using GPS, Barletta <jats:italic>et al.</jats:italic> found that the viscosity of the mantle under the West Antarctic Ice Sheet is much lower than expected. This means that as ice is lost, the crust rebounds much faster than previously expected. Although estimates of total ice loss have to be revised upward, the surprising finding indicates that the ice sheet may stabilize against catastrophic collapse. </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="6395" page="1335" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aao1447">1335</jats:related-article> </jats:p>