Catálogo de publicaciones - revistas

<jats:title>How algae turn tides toxic</jats:title> <jats:p> Algal blooms can devastate marine mammal communities through the production of neurotoxins that accumulate within the food web. Brunson <jats:italic>et al.</jats:italic> identified a cluster of genes associated with biosynthesis of the neurotoxin domoic acid in a marine diatom (see the Perspective by Pohnert <jats:italic>et al.</jats:italic> ). In vitro experiments established a series of enzymes that create the core structure of the toxin. Knowledge of the genes involved in domoic acid production will allow for genetic monitoring of algal blooms and aid in identifying conditions that trigger toxin production. </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="6409" page="1356" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aau0382">1356</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6409" page="1308" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aau9067">1308</jats:related-article> </jats:p>

<jats:title>Making ultrafast cycles of light</jats:title> <jats:p> The ability to generate coherent optical frequency combs has had a huge impact on precision metrology, imaging, and sensing applications. On closer inspection, the broadband “white light” generated through the interaction of femtosecond mode-locked laser pulses is composed of billions or trillions of precisely spaced wavelengths of light. Carlson <jats:italic>et al.</jats:italic> demonstrate an alternative to the mode-locked laser approach—the electro-optic modulation of a continuous-wave laser light source can also generate optical frequency combs (see the Perspective by Torres-Company). The electro-optic modulation techniques can operate at much higher repetition rates than mode-locked lasers, which means they could potentially yield even more precise measurements. </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="6409" page="1358" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aat6451">1358</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6409" page="1316" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aau7507">1316</jats:related-article> </jats:p>

<jats:title>Two ways out of an oxetane</jats:title> <jats:p> Oxetanes are highly reactive four-membered rings that contain three carbon atoms and an oxygen atom. Recently, they were implicated as transient intermediates in Lewis acid–catalyzed intramolecular metathesis reactions of ketones with olefins. Ludwig <jats:italic>et al.</jats:italic> now report that by replacing the Lewis acid with a strong Brønsted acid, they can change the course of the oxetane ring-opening. In a so-called interrupted metathesis, the oxygen atom migrates and then departs through dehydration, while the remaining carbon framework cyclizes to form tetrahydrofluorene compounds. </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="6409" page="1363" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aar8238">1363</jats:related-article> </jats:p>

<jats:title>Arenes and amides from a single source</jats:title> <jats:p> Pharmaceutical synthesis often requires the formation of adjacent carbon-carbon and carbon-nitrogen bonds. Monos <jats:italic>et al.</jats:italic> present a method that delivers the carbon and nitrogen components in a single reagent, specifically, an aryl ring tethered through sulfur dioxide to an amide. A light-activated catalyst primes an olefin to react with the nitrogen, which in turn leads to migration of the aryl ring and loss of the sulfur bridge. The efficient room-temperature process is applicable to a variety of different arenes, including heterocycles. </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="6409" page="1369" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aat2117">1369</jats:related-article> </jats:p>