Catálogo de publicaciones - revistas

<jats:title>Bioremediation from disabled self-destruction</jats:title> <jats:p> Explosives used in mining, construction, or military operations leave behind contaminated soils. Although bioremediation could help, plants do not thrive on these soils. Johnston <jats:italic>et al.</jats:italic> have now found out why (see the Perspective by Noctor). An enzyme found in plant mitochondria and chloroplasts spins out of control when given the explosive TNT, generating toxic reactive oxygen species and subverting biochemical pathways. With the key enzyme disabled, the plants are better at tolerating and accumulating TNT. These results point the way to future bioremediation and herbicide strategies. </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="6252" page="1072" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aab3472">1072</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6252" page="1052" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aad0941">1052</jats:related-article> </jats:p>

<jats:title>Nonequilibrium transient self-assembly</jats:title> <jats:p> In biology, the constant supply of energy can drive a system to be far from its equilibrium conditions and allow for useful work to be done. In contrast, in most synthetic systems, there is a drive toward lower energy states. Boekhoven <jats:italic>et al.</jats:italic> made a molecule that can switch between a nonassociating state and an associating state through the addition of a chemical fuel (see the Perspective by Van der Zwagg and Meijer). The lifetime, stiffness, and regenerative behavior of the self-assembled state could be controlled and tuned by the kinetics of fuel conversion. </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="6252" page="1075" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aac6103">1075</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6252" page="1056" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aad0194">1056</jats:related-article> </jats:p>

<jats:title>Welcoming steel's new complexion</jats:title> <jats:p> Metals have a number of famous properties, including good strength and ductility. Controlling these properties frequently requires modifying the number and type of structural defects in a metal alloy. Kuzmina <jats:italic>et al.</jats:italic> produced a new type of defect, called a linear complexion, in magnesium-rich steel (see the Perspective by Kaplan). These complexions are chemically and structurally distinct regions located inside a linear defect and are isolated from the bulk by a layer of dislocations. The discovery suggests a new path for targeting defects and improving alloy development. </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="6252" page="1080" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aab2633">1080</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6252" page="1059" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aac9623">1059</jats:related-article> </jats:p>

<jats:title>A superior mix of big and small</jats:title> <jats:p> Graphene is often described as an unrolled carbon nanotube. However, although nanotubes are known for their exceptional mechanical and conductivity properties, the same is not true of graphene-based fibers. Xin <jats:italic>et al.</jats:italic> intercalated small fragments of graphene into the gaps formed by larger graphene sheets that had been coiled into fibers. Once annealed, the large sheets provided pathways for conduction, while the smaller fragments helped reinforce the fibers. The result? Superior thermal and electrical conductivity and mechanical strength. </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="6252" page="1083" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aaa6502">1083</jats:related-article> </jats:p>

<jats:title>Iron lends power to traces of palladium</jats:title> <jats:p> Palladium (Pd) is a mainstay of chemical catalysis. The precious metal has a knack for forging carbon-carbon (C-C) bonds. Handa <jats:italic>et al.</jats:italic> now report that when mixed in a specific preparation with iron, just parts per million of Pd suffice to catalyze the C-C bond–forming Suzuki coupling reaction. The addition of surfactants allowed the reaction to proceed in water. The protocol bodes well for conserving Pd in pharmaceutical and agrochemical synthesis. </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="6252" page="1087" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aac6936">1087</jats:related-article> </jats:p>

<jats:title>The bigger they are, the harder they fall</jats:title> <jats:p> The magnitude 7.8 Gorkha earthquake hit Nepal on 25 April 2015. The earthquake killed thousands and caused great damage. Galetzka <jats:italic>et al.</jats:italic> determined how the fault that caused this earthquake ruptured. The rupture showed a smooth slip pulse 20 km wide that moved eastward along the fault over about 6 s. The nature of the rupture limited damage to regular dwellings but generated shaking that collapsed taller structures. </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="6252" page="1091" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aac6383">1091</jats:related-article> </jats:p>

<jats:title>Toward opioids without poppy fields</jats:title> <jats:p> Producing opioids without having to depend on field-grown poppies would be of great benefit. Synthetic production could potentially produce more-effective drugs with fewer side effects. Now, Galanie <jats:italic>et al.</jats:italic> have engineered yeast to produce the opioid compounds thebaine and hydrocodone, starting from sugar (see the Perspective by Nielsen). The amounts produced so far are tiny compared with what would be needed commercially. Future optimization and scaleup are the next challenge. </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="6252" page="1095" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aac9373">1095</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6252" page="1050" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aad2081">1050</jats:related-article> </jats:p>

<jats:title>Estimating bacterial growth dynamics</jats:title> <jats:p> The pattern of sequencing read coverage of bacteria in metagenomic samples reflects the growth rate. This pattern is predictive of growth because bacterial genomes are circular, with a single origin of replication. So during growth, copies of the genome accumulate at the origin. Korem <jats:italic>et al.</jats:italic> use the ratio of copy number at the origin to the copy number at the terminus to detect the actively growing species in a microbiome (see the Perspective by Segre). They could spot the difference between virulent and avirulent strains, population diurnal oscillations, species that are growing in irritable bowel disease, and what happens when a host's diet changes. Results were consistent in chemostats, in mice, and in human fecal samples. </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="6252" page="1101" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aac4812">1101</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6252" page="1058" related-article-type="in-this-issue" vol="349" xlink:href="10.1126/science.aad0781">1058</jats:related-article> </jats:p>