Catálogo de publicaciones - revistas

<jats:title>Polarization hits a bull's-eye</jats:title> <jats:p> Polymer-based ferroelectric materials are attractive because they can be solution processed cheaply and have much greater flexibility than ceramics. Guo <jats:italic>et al.</jats:italic> found concentric circular bands of polarization in a ferroelectric polymer that look like a bull's-eye target (see the Perspective by Martin). This self-organized toroidal texture is aligned perpendicularly to the axis of the polymer chains, allowing the authors to demonstrate selective absorption of infrared radiation and manipulation of terahertz radiation. This distinct structure in a polymer could be of interest for exploring and using other exotic effects. </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="6533" page="1050" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abc4727">1050</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6533" page="992" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg4477">992</jats:related-article> </jats:p>

<jats:title>Electron dynamics in time and space</jats:title> <jats:p> Following molecular excitation and electron transfer processes in time and space within a single experiment is a long-standing goal of spectroscopy in the field of chemistry. Wallauer <jats:italic>et al.</jats:italic> combined tomographic photoemission imaging with a femtosecond pump-probe scheme to trace the excited state molecular orbitals of surface-adsorbed molecules with both spatial and temporal resolution. The present demonstration opens a new window for investigating the ultrafast electron transfer dynamics in such processes as chemical reactions on surfaces and intermolecular charge transfers. </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="6533" page="1056" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abf3286">1056</jats:related-article> </jats:p>

<jats:title>A new way to “see” color</jats:title> <jats:p> Color perception is an important aspect of the way many organisms navigate their world. The ability to perceive color has thus far thought to depend on the presence of either eyes or minimally receptive cells containing opsin receptor genes. Ghosh <jats:italic>et al.</jats:italic> show that foraging <jats:italic>Caenorhabditis elegans</jats:italic> roundworms, which do not have eyes or opsins, can distinguish a blue color indicative of a toxin released by bacterial mats (see the Perspective by Neal and Vosshall). They suggest that the worms do this through the detection of the ratio between blue and amber light, a process dependent on at least two cellular stress-response genes. Different strains of <jats:italic>C. elegans</jats:italic> responded to different ratios, suggesting that this pathway plays an ecological role. </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="6533" page="1059" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abd3010">1059</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6533" page="995" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abg5201">995</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>