Catálogo de publicaciones - revistas

<jats:p> Real-time atomic force microscopy provides insights into complex processes associated with crystal growth. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="729" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1250984">Lupulescu and Rimer</jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> Advances in synthesis are leading to thermoset plastics that can be converted to the starting monomers. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="732" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251484"> García <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p>Uncovering how an RNA-protein molecular scalpel targets DNA will advance our ability to engineer genomes.</jats:p>

<jats:title>Degrees of Separation</jats:title> <jats:p> Proteins embedded in membranes represent an interesting point of communication between the cell and its environment, but their localization to membranes can make them difficult to study. <jats:bold> Jones <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="711" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251358">711</jats:related-article> ) found an approach to catalog thousands of interactions involving membrane proteins and membrane-associated signaling machinery—including many previously uncharacterized proteins. With a focus on the model plant <jats:italic>Arabidopsis</jats:italic> , several of the identified interactions fill gaps in important signal transduction chains, while others point to functions for enigmatic unknown proteins. </jats:p>

<jats:title>Out of the Air</jats:title> <jats:p> New-particle formation from gaseous precursors in the atmosphere is a complex and poorly understood process with importance in atmospheric chemistry and climate. Laboratory studies have had trouble reproducing the particle formation rates that must occur in the natural world. <jats:bold> Riccobono <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="717" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1243527">717</jats:related-article> ) used the CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN to recreate a realistic atmospheric environment. Sulfuric acid and oxidized organic vapors in typical natural concentrations caused particle nucleation at similar rates to those observed in the lower atmosphere. </jats:p>

<jats:title>Untwisting the Spin Spiral</jats:title> <jats:p> Ultracold Fermi gases in the so-called unitary regime—where the diverging interactions between atoms make their thermodynamics universal—are an excellent test bed for an array of strongly interacting matter systems. The transport characteristics in this regime are particularly intriguing, and a discrepancy between two- and three-dimensional transport coefficients has been observed. <jats:bold> Bardon <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="722" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1247425">722</jats:related-article> ) studied the demagnetization dynamics of a three-dimensional Fermi gas. The gas was initially polarized along a single direction and was noninteracting. An applied magnetic field gradient then caused a spin spiral to form; as the gas relaxed from this state, the authors extracted the diffusion coefficient and observed the buildup of interactions between the atoms. </jats:p>

<jats:title>Controlling Chiral Light Emission</jats:title> <jats:p> Circularly polarized light plays important roles in a number of applications such as displays, communication, and sensing. Thus, the ability to produce compact and readily controllable polarized light sources is important, and dichalcogenide materials such as tungsten diselenide may provide a route to such sources. <jats:bold> Zhang <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="725" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251329">725</jats:related-article> , published online 17 April; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="702" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1254496">Zaumseil</jats:related-article> </jats:bold> ) formed an electric-double-layer transistor structure with WSe2 and used a gated ionic liquid to control the carrier density. Electrical control of the output light was achieved with the polarization being switched by reversing the polarity of the applied field and injected charge. </jats:p>

<jats:title>Crystal Growth</jats:title> <jats:p> Two main routes for the growth of crystalline species are either via molecule-by-molecule attachment to existing nuclei or via the addition of preformed metastable precursors, but do these mechanisms need to be mutually exclusive? <jats:bold>Lupulescu and Rimer</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="729" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1250984">729</jats:related-article> ; see the Perspective by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="705" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1254259"> <jats:bold>Dandekar and Doherty</jats:bold> </jats:related-article> ) developed an in situ atomic force microscopy (AFM) technique to study the crystallization of materials under extreme conditions of temperature (25° to 300°C) and alkalinity (up to a pH of 13). The growth of the zeolite silicalite-1 involved both the attachment of metastable precursors and of individual molecules. </jats:p>

<jats:title>Recyclable Thermoset Polymers</jats:title> <jats:p> The high mechanical strength and durability of thermoset polymers are exploited in applications such as composite materials, where they form the matrix surrounding carbon fibers. The thermally driven polymerization reaction is usually irreversible, so it is difficult to recycle the constituent monomers and to remove and repair portions of a composite part. <jats:bold> García <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="732" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251484">732</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="706" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1254401">Long</jats:related-article> </jats:bold> ) now describe a family of polymers formed by condensation of paraformaldehyde with bisanilines that could form hard thermoset polymers or, when more oxygenated, produce self-healing gels. Strong acid digestion allowed recovery of the bisaniline monomers. </jats:p>

<jats:title>Antarctic Collapse</jats:title> <jats:p> The West Antarctic Ice Sheet (WAIS) is particularly vulnerable to ocean warming-induced collapse. The Thwaites Glacier of West Antarctica is one of the largest WAIS regional contributors to sea level rise, and has been considered to be potentially unstable for many years. <jats:bold> Joughin <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6185" page="735" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1249055">735</jats:related-article> ) used a combination of a numerical model and observations of its recent geometry and movement to investigate the stability of the Thwaites Glacier. The glacier has already entered the early stages of collapse, and rapid and irreversible collapse is likely in the next 200 to 1000 years. </jats:p>