Catálogo de publicaciones - revistas

<jats:title>The lazy way to keep cool in the sun</jats:title> <jats:p> Passive radiative cooling requires a material that radiates heat away while allowing solar radiation to pass through. Zhai <jats:italic>et al.</jats:italic> solve this riddle by constructing a metamaterial composed of a polymer layer embedded with microspheres, backed with a thin layer of silver (see the Perspective by Zhang). The result is an easy-to-manufacture material near the theoretical limit for daytime radiative cooling. The translucent and flexible film can be made in large quantities for a variety of energy technology applications. </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="6329" page="1062" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aai7899">1062</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6329" page="1023" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aam8566">1023</jats:related-article> </jats:p>

<jats:title>Going way off resonance</jats:title> <jats:p> Single atomic layers of transition metal dichalcogenide (TMD) materials have two nonequivalent valleys in their electronic structure. When researchers shine visible light on these monolayers, left-circularly polarized light modifies the electronic levels in one valley but not the other. Sie <jats:italic>et al.</jats:italic> studied the material WS <jats:sub>2</jats:sub> . They found that in the infrared regime, if the frequency of the light was far away from the resonance, energy levels in both valleys were affected. The so-called Bloch-Siegert effect could explain the energy shift in the “wrong” valley. The findings should be important for the manipulation of valleytronic properties of TMDs. </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="6329" page="1066" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aal2241">1066</jats:related-article> </jats:p>

<jats:title>The long view of ocean pH</jats:title> <jats:p>The acid-base balance of the oceans has been critical in maintaining Earth's habitability and allowing the emergence of early life. Despite this importance, systematic estimates of historical seawater pH are lacking. Halevy and Bachan developed a model of seawater chemistry and pH over time scales exceeding ∼100 million years. Their highly robust probabilistic history of seawater pH and chemistry reflects evolving properties of Earth's atmosphere, oceans, and crust. Seawater pH increased from early Archean values of ∼6.5 to 7.0 to more recent values of ∼7.5 to 9.0 mostly as a result of solar brightening and decreasing interaction between seawater and oceanic crust.</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="6329" page="1069" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aal4151">1069</jats:related-article> </jats:p>

<jats:title>To scratch or not to scratch</jats:title> <jats:p> Observing someone else scratching themselves can make you want to do so. This contagious itching has been observed in monkeys and humans, but what about rodents? Yu <jats:italic>et al.</jats:italic> found that mice do imitate scratching when they observe it in other mice. The authors identified a brain area called the suprachiasmatic nucleus as a key circuit for mediating contagious itch. Gastrin-releasing peptide and its receptor in the suprachiasmatic nucleus were necessary and sufficient to transmit this contagious behavior. </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="6329" page="1072" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aak9748">1072</jats:related-article> </jats:p>

<jats:title>Siren molecule calls loudly to mosquitoes</jats:title> <jats:p> People infected by malaria become more attractive to the mosquito vectors of the disease, which facilitates the spread of malaria. Emami <jats:italic>et al.</jats:italic> found that red blood cells of the host respond to a parasite-derived isoprenoid called HMBPP by increasing the production of carbon dioxide and several monoterpenes and aldehydes. Mosquitoes fed HMBPP-spiked blood displayed malaria parasite–specific changes in gene transcription, which reinforced attractiveness for the mosquito. HMBPP also stimulates mosquito feeding and malaria parasite reproduction. Thus, the parasite manipulates its mammalian host to make it more attractive to the insect vectors and exploits the same molecule to amplify transmission. </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="6329" page="1076" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aah4563">1076</jats:related-article> </jats:p>

<jats:title>Polycomb group gene silencing</jats:title> <jats:p> Histone proteins wrap around DNA to form nucleosomes that package metazoan DNA into the nucleus. Chromatin compaction is also believed to be critical for the repression of homeotic genes by the Polycomb repressive complex 1 (PRC1) during development. Lau <jats:italic>et al.</jats:italic> used mutagenesis and expression analyses to examine this gene silencing mechanism. Altering the PRC1 compaction region affected transcriptional repression and patterning of the mouse body axis. Thus, chromatin compaction may drive the stable and heritable silencing of genes involved in body patterning. </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="6329" page="1081" related-article-type="in-this-issue" vol="355" xlink:href="10.1126/science.aah5403">1081</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>