Catálogo de publicaciones - revistas

<jats:title>Simplifying DNA origami design</jats:title> <jats:p> Many intricate nanostructures have been made with DNA origami. This process occurs when a long DNA scaffold develops a particular shape after hybridization with short staple strands. Most designs, however, require a difficult iterative procedure of refining the base pairing. Veneziano <jats:italic>et al.</jats:italic> now report algorithms that automate the design of arbitrary DNA wireframe structures. Synthesizing and structurally characterizing a variety of nanostructures allowed for verification of the algorithms' accuracy. </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="6293" page="1534" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf4388">1534</jats:related-article> </jats:p>

<jats:title>Mounting the intestinal barricades</jats:title> <jats:p> Gut microbiota are important for health and well-being, but they need to be kept under control and prevented from doing any harm. Birchenough <jats:italic>et al.</jats:italic> investigated the microbial molecules that trigger protective mucus secretion from a class of goblet cells in the colon. Once the molecules are detected, an alarm signal is transmitted from these cells via innate immune signal mediators and inflammasome components to adjacent cells, generating more mucus and repelling the invaders. Subsequently, the sentinel goblet cells are expelled from the epithelium and their remains may also add to the protective barricade. </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="6293" page="1535" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf7419">1535</jats:related-article> </jats:p>

<jats:title>Holding kinases at the ready</jats:title> <jats:p> About 60% of kinases only reach their active state in the presence of the molecular chaperone Hsp90 and its co-chaperone Cdc37. It is unclear how the chaperones facilitate kinase function or why only some kinases are chaperone-dependent. Verba <jats:italic>et al.</jats:italic> determined a 3.9 Å cryo–electron microscopy structure of Hsp90:Cdc37 in complex with the kinase Cdk4. Together, Hsp90 and Cdc37 trap the kinase in an open, partially unfolded state. Taking on this state probably has direct functional benefits. </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="6293" page="1542" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf5023">1542</jats:related-article> </jats:p>

<jats:title>Bosons refusing to thermalize in 2D</jats:title> <jats:p> Messy, interacting quantum-mechanical systems are difficult to analyze theoretically. In a single spatial dimension, the calculations are still tractable, and experiments have recently confirmed the prediction that sufficiently strong disorder can disrupt the transport of interacting particles. In two dimensions, however, the theoretical blueprint is missing. Choi <jats:italic>et al.</jats:italic> used single-site imaging of cold <jats:sup>87</jats:sup> Rb atoms in an optical lattice to show that similar localization occurs in two-dimensional (2D) systems. The study highlights the power of quantum simulation to solve problems that are currently inaccessible to classical computing techniques. </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="6293" page="1547" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf8834">1547</jats:related-article> </jats:p>

<jats:title>Quantum enhanced metrology</jats:title> <jats:p> Exploiting the quantum-mechanical properties of quantum systems offer the possibility of developing devices for enhanced precision measurement and sensing applications. These devices have, however, required low-noise detection capabilities that have hampered their development. Hosten <jats:italic>et al.</jats:italic> describe a method that manipulates a coherent cloud of cold rubidium atoms in a way that relaxes the ultrasensitive detection requirements. The general method may be applied to other coherent quantum systems. </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="6293" page="1552" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf3397">1552</jats:related-article> </jats:p>

<jats:title>Catalysis gets all tied up in knots</jats:title> <jats:p> Over the past decade, chemists have used metal ion templating to prepare a wide variety of knotted molecular strands. Marcos <jats:italic>et al.</jats:italic> now show that one such pentafoil knot can be applied to catalysis. When held taut by zinc ions, the knot can capture a chloride or bromide ion from a halocarbon, thereby unleashing the reactivity of the residual cation for applications such as Lewis acid catalysis. Removing the zinc ions lowers the knot's affinity for the halides, offering a reversible modulation mechanism for the catalysis. </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="6293" page="1555" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf3673">1555</jats:related-article> </jats:p>

<jats:title>Shining brightly in the early universe</jats:title> <jats:p> Galaxies that formed early in the history of the universe were powerful sources of ultraviolet radiation. This radiation ionized the surrounding intergalactic medium during the “epoch of reionization.” Inoue <jats:italic>et al.</jats:italic> detected atomic emission lines from a galaxy at high redshift—seen as it was when the universe was only ~5% of its current age (see the Perspective by De Breuck). Data from optical, infrared, and submillimeter observatories determined its gas and dust content and the amount of ultraviolet radiation it emitted. Studying similar galaxies in such a manner will allow astronomers to determine how the first galaxies formed, evolved, and influenced their surroundings. </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="6293" page="1559" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf0714">1559</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6293" page="1520" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf9761">1520</jats:related-article> </jats:p>

<jats:title>How to single out the right atoms</jats:title> <jats:p> For a quantum computer to be useful, its qubits have to be able to change their state in response to external stimuli. But when a large number of qubits are packed in a three-dimensional (3D) structure to optimize the use of space, altering one qubit can unintentionally change the state of others. Wang <jats:italic>et al.</jats:italic> devised a clever way to perform high-fidelity quantum gates only on intended qubits in a 3D array of Cs atoms. Although the operation initially changed the state of some of the other atoms, additional manipulation recovered their original state. The technique may be applicable to other quantum computing implementations. </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="6293" page="1562" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf2581">1562</jats:related-article> </jats:p>

<jats:title>Multimetal nanoparticle synthesis</jats:title> <jats:p> Multicomponent nanoparticles can be difficult to synthesize. Rather than mixing in one type of particle, the compounds often separate and form distinct particles. Using dip-pen lithography, Chen <jats:italic>et al.</jats:italic> show how adding reactants to very small volumes forces the reactants to form single particles containing various combinations of five different transition metal ions. Scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy revealed the shapes of the nanoparticles and how metallic composition varied within them. For example, the quinary particle containing gold, silver, cobalt, copper, and nickel consisted of three domains of binary alloys. </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="6293" page="1565" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf8402">1565</jats:related-article> </jats:p>

<jats:title>Versatile embryonic neural crest cells</jats:title> <jats:p> Neural crest cells wander far and wide through the developing vertebrate embryo to build tissues such as the jaw and peripheral nerves. Simoes-Costa <jats:italic>et al.</jats:italic> show, studying chick embryos, that not all neural crest cells are alike. The expression of a handful of transcription factors identifies cranial neural crest cells as distinct from trunk neural crest cells. Ectopic expression of some of these factors caused trunk neural crest cells to function as cranial neural crest cells. Thus, embryonic neural crest cells carry subspecialties that are defined but malleable. </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="6293" page="1570" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf2729">1570</jats:related-article> </jats:p>