Catálogo de publicaciones - revistas

<jats:title>Perovskite/CIGS tandem cells</jats:title> <jats:p> Tandem solar cells can boost efficiency by using more of the available solar spectrum. Han <jats:italic>et al.</jats:italic> fabricated a two-terminal tandem cell with an inorganicorganic hybrid perovskite top layer and a Cu(In,Ga)Se <jats:sub>2</jats:sub> (CIGS) bottom layer. Control of the roughness of the CIGS surface and the use of a heavily doped organic hole transport layer were crucial to achieve a 22.4% power conversion efficiency. The unencapsulated tandem cells maintained almost 90% of their efficiency after 500 hours of operation under ambient conditions. </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="6405" page="904" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aat5055">904</jats:related-article> </jats:p>

<jats:title>Tiny cargos ferried along a track</jats:title> <jats:p> Control of molecules at the nanometer scale requires motors that convert potential energy into movement. Qing <jats:italic>et al.</jats:italic> designed a small molecule that could hop along a track of cysteine residues within a membrane-embedded protein pore. The direction of processive movement along the track was reversible, driven by an applied potential across the membrane. Cargos were attached to a carrier motor, and their position and chemical identity read out from changes in the current through the pore. These features enabled repeat observations of a single molecule as it moved back and forth on the track. </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="6405" page="908" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aat3872">908</jats:related-article> </jats:p>

<jats:title>Carbonyls in the s block</jats:title> <jats:p> Conventional wisdom in chemistry distinguishes transition metals from other elements by their use of d orbitals in bonding. Wu <jats:italic>et al.</jats:italic> now report that alkaline earth metals can slide their electrons from s- to d-orbital bonding motifs as well (see the Perspective by Armentrout). Calcium, strontium, and barium all form coordination complexes with a cubic arrangement of eight carbonyl ligands and an 18-electron valence shell. The compounds were characterized in frozen neon matrices by vibrational spectroscopy and in gas phase by mass spectrometry. </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="6405" page="912" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aau0839">912</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6405" page="849" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aau6622">849</jats:related-article> </jats:p>

<jats:title>Warming, crops, and insect pests</jats:title> <jats:p> Crop responses to climate warming suggest that yields will decrease as growing-season temperatures increase. Deutsch <jats:italic>et al.</jats:italic> show that this effect may be exacerbated by insect pests (see the Perspective by Riegler). Insects already consume 5 to 20% of major grain crops. The authors' models show that for the three most important grain crops—wheat, rice, and maize—yield lost to insects will increase by 10 to 25% per degree Celsius of warming, hitting hardest in the temperate zone. These findings provide an estimate of further potential climate impacts on global food supply and a benchmark for future regional and field-specific studies of crop-pest-climate interactions. </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="6405" page="916" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aat3466">916</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6405" page="846" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aau7311">846</jats:related-article> </jats:p>

<jats:title>Future predictions from paleoecology</jats:title> <jats:p> Terrestrial ecosystems will be transformed by current anthropogenic change, but the extent of this change remains a challenge to predict. Nolan <jats:italic>et al.</jats:italic> looked at documented vegetational and climatic changes at almost 600 sites worldwide since the last glacial maximum 21,000 years ago. From this, they determined vegetation responses to temperature changes of 4° to 7°C. They went on to estimate the extent of ecosystem changes under current similar (albeit more rapid) scenarios of warming. Without substantial mitigation efforts, terrestrial ecosystems are at risk of major transformation in composition and structure. </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="6405" page="920" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aan5360">920</jats:related-article> </jats:p>

<jats:title>The structure of the genome</jats:title> <jats:p> Beyond the sequence of the genome, its three-dimensional structure is important in regulating gene expression. To understand cell-to-cell variation, the structure needs to be understood at a single-cell level. Chromatin conformation capture methods have allowed characterization of genome structure in haploid cells. Now, Tan <jats:italic>et al.</jats:italic> report a method called Dip-C that allows them to reconstruct the genome structures of single diploid human cells. Their examination of different cell types highlights the tissue dependence of three-dimensional genome 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="6405" page="924" related-article-type="in-this-issue" vol="361" xlink:href="10.1126/science.aat5641">924</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>