Catálogo de publicaciones - revistas

<jats:p> High-resolution spectroscopy helps to elucidate the highly dynamic structure of protonated methane. <jats:named-content content-type="related-content"> [Also see Perspective by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6228" page="1313" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa6935">Oka</jats:related-article> ] </jats:named-content> </jats:p>

<jats:title>Fast, continuous, 3D printing</jats:title> <jats:p> Although three-dimensional (3D) printing is now possible using relatively small and low-cost machines, it is still a fairly slow process. This is because 3D printers require a series of steps to cure, replenish, and reposition themselves for each additive cycle. Tumbleston <jats:italic>et al.</jats:italic> devised a process to effectively grow solid structures out of a liquid bath. The key to the process is the creation of an oxygen-containing “dead zone” between the solid part and the liquid precursor where solidification cannot occur. The precursor liquid is then renewed by the upward movement of the growing solid part. This approach made structures tens of centimeters in size that could contain features with a resolution below 100 µm. </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="6228" page="1349" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa2397">1349</jats:related-article> </jats:p>

<jats:title> Finding <jats:italic>Homo</jats:italic> nearly 3 million years ago </jats:title> <jats:p> The fossil record of humans is notoriously patchy and incomplete. Even so, skeletal remains and artifacts unearthed in Africa in recent decades have done much to illuminate human evolution. But what is the origin of the genus <jats:italic>Homo</jats:italic> ? Villmoare <jats:italic>et al.</jats:italic> found a fossil mandible and teeth from the Afar region in Ethiopia. The find extends the record of recognizable <jats:italic>Homo</jats:italic> by at least half a million years, to almost 2.8 million years ago. The morphological traits of the fossil align more closely with <jats:italic>Homo</jats:italic> than with any other hominid genus. DiMaggio <jats:italic>et al.</jats:italic> confirm the ancient date of the site and suggest that these early humans lived in a setting that was more open and arid than previously thought. </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="6228" page="1352" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa1343">1352</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6228" page="1355" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa1415">1355</jats:related-article> </jats:p>

<jats:title> Finding <jats:italic>Homo</jats:italic> nearly 3 million years ago </jats:title> <jats:p> The fossil record of humans is notoriously patchy and incomplete. Even so, skeletal remains and artifacts unearthed in Africa in recent decades have done much to illuminate human evolution. But what is the origin of the genus <jats:italic>Homo</jats:italic> ? Villmoare <jats:italic>et al.</jats:italic> found a fossil mandible and teeth from the Afar region in Ethiopia. The find extends the record of recognizable <jats:italic>Homo</jats:italic> by at least half a million years, to almost 2.8 million years ago. The morphological traits of the fossil align more closely with <jats:italic>Homo</jats:italic> than with any other hominid genus. DiMaggio <jats:italic>et al.</jats:italic> confirm the ancient date of the site and suggest that these early humans lived in a setting that was more open and arid than previously thought. </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="6228" page="1352" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa1343">1352</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6228" page="1355" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa1415">1355</jats:related-article> </jats:p>

<jats:title>From iron clusters to iron mineral</jats:title> <jats:p> Growing a mineral out of solution, either in the lab or in nature, requires the assembly of atoms or clusters of ions. The structure of some common iron oxides hints that tiny iron-oxygen clusters may serve as mineral building blocks, but isolating these often unstable clusters is challenging. Sadeghi <jats:italic>et al.</jats:italic> not only isolated but were able to control the growth and dissolution of an iron-oxygen cluster that is a likely precursor to the most common iron oxide mineral, ferrihydrite. </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="6228" page="1359" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa4620">1359</jats:related-article> </jats:p>

<jats:title>Targeting metabolism to tackle seizures</jats:title> <jats:p> About 1% of us suffer from epilepsy. Unfortunately, presently available drugs do not work for a third of epileptic patients. Sada <jats:italic>et al.</jats:italic> wanted to develop compounds to treat drug-resistant epilepsy (see the Perspective by Scharfman). They focused on a metabolic pathway in the brain, the astrocyte-neuron lactate shuttle. They found that lactate dehydrogenase, a key molecule in nerve cell metabolism, controls brain excitability. Searching for a substance that selectively targets this molecule, they found a potential anti-epileptic drug that strongly suppressed drug-resistant epilepsy in an animal model. </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="6228" page="1362" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa1299">1362</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6228" page="1312" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa9607">1312</jats:related-article> </jats:p>

<jats:title>Measuring translation in space and time</jats:title> <jats:p> The ribosome translates the information contained within messenger RNAs (mRNAs) into proteins. When and where ribosomes encounter mRNAs can regulate gene expression. Halstead <jats:italic>et al.</jats:italic> developed an RNA biosensor that allows single molecules of mRNAs that have never been translated to be distinguished from ones that have undergone translation by the ribosome in living cells (see the Perspective by Popp and Maquat). The authors demonstrated the utility of their technique by examining the spatial and temporal regulation of translation in single cells and in <jats:italic>Drosophila</jats:italic> oocytes during 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="6228" page="1367" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa3380">1367</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6228" page="1316" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa9484">1316</jats:related-article> </jats:p>

<jats:title>RNA kinetics may define regulatory hierarchy</jats:title> <jats:p> The double-helical structure of DNA suggests immediately how nucleic acid polymers can recognize and bind to homologous sequences. Target recognition by RNA is vital in many biological processes. Fei <jats:italic>et al.</jats:italic> used super-resolution microscopy of tagged RNAs and computer modeling to understand how RNA-RNA base-pairing reactions occur in vivo. They studied a small RNA (sRNA) that targets a messenger RNA (mRNA) for degradation in bacteria. They observed a slow rate of association as the sRNA searched for its mRNA target, but thereafter a fast rate of dissociation. This explains the need for high concentrations of sRNA to cause mRNA degradation. The sRNA found different target mRNAs at different rates, allowing the generation of a regulatory hierarchy. </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="6228" page="1371" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.1258849">1371</jats:related-article> </jats:p>

<jats:title>Keeping stem cells in tip top condition</jats:title> <jats:p> Stem cells are important in the maintenance and growth of tissues. For the health of the organism as a whole, it is important that only healthy stem cells be used. Mohrin <jats:italic>et al.</jats:italic> elucidated a regulatory branch of the mitochondrial unfolded protein response that is coupled to cellular energy metabolism and proliferation in stem cells (see the Perspective by Ocampo and Belmonte). Mitochondrial protein folding stress triggered a metabolic checkpoint that regulates the cell cycle. Deregulation of this pathway interfered with stem cell quiescence and compromised regenerative function. </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="6228" page="1374" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa2361">1374</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6228" page="1319" related-article-type="in-this-issue" vol="347" xlink:href="10.1126/science.aaa9608">1319</jats:related-article> </jats:p>

<jats:p>On this week's show: The future of robotic materials, and a roundup of daily news stories.</jats:p>