Catálogo de publicaciones - revistas

<jats:title>Optimizing surface passivation</jats:title> <jats:p> Unproductive charge recombination at surface defects can limit the efficiency of hybrid perovskite solar cells, but these defects can be passivated by the binding of small molecules. Wang <jats:italic>et al.</jats:italic> studied three such small molecules—theophylline, caffeine, and theobromine—that bear both carbonyl and amino groups. For theophylline, hydrogen bonding of the amino hydrogen to surface iodide optimized the carbonyl interaction with a lead antisite defect and improved the efficiency of a perovskite cell from 21 to 22.6%. </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="6472" page="1509" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aay9698">1509</jats:related-article> </jats:p>

<jats:title>A carbonylation path to a nylon precursor</jats:title> <jats:p> Adipic acid and its esters are manufactured on a massive scale, primarily to produce nylon. However, the standard route requires large quantities of corrosive nitric acid. J. Yang <jats:italic>et al.</jats:italic> present an efficient alternative route whereby a palladium catalyst adds carbon monoxide to each end of butadiene (see the Perspective by Schaub). Both reactants are available at commodity scale, and the reaction produces no by-products. An optimized bidentate phosphine ligand bearing a pyridine substituent for proton shuttling proved key to attaining the necessary selectivity. </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="6472" page="1514" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz1293">1514</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6472" page="1447" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz6459">1447</jats:related-article> </jats:p>

<jats:title>The diverse way that languages convey emotion</jats:title> <jats:p> It is unclear whether emotion terms have the same meaning across cultures. Jackson <jats:italic>et al.</jats:italic> examined nearly 2500 languages to determine the degree of similarity in linguistic networks of 24 emotion terms across cultures (see the Perspective by Majid). There were low levels of similarity, and thus high variability, in the meaning of emotion terms across cultures. Similarity of emotion terms could be predicted on the basis of the geographic proximity of the languages they originate from, their hedonic valence, and the physiological arousal they evoke. </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="6472" page="1517" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaw8160">1517</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6472" page="1444" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aba1763">1444</jats:related-article> </jats:p>

<jats:title>A different way for γδ T cells to bind</jats:title> <jats:p> The ligands bound by γδ T cell receptors (TCRs) are less well characterized than those of their αβ TCR cousins, which are antigens presented by major histocompatibility complex (MHC) and related proteins. Le Nours <jats:italic>et al.</jats:italic> identified a phenotypically diverse γδ T cell subset in human tissues that reacts to MHC-related protein 1 (MR1), which presents vitamin B derivatives. A crystal structure of a γδ TCR–MR1–antigen complex revealed that some of these TCRs can bind underneath the MR1 antigen-binding cleft instead of recognizing the presented antigen. This work thus uncovers an additional ligand for γδ T cells and reconceptualizes the nature of T cell antigen recognition. </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="6472" page="1522" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aav3900">1522</jats:related-article> </jats:p>

<jats:title>Macrocycles made easy</jats:title> <jats:p> Macrocycles, which are molecules with large rings of 12 or more atoms, are challenging to produce by intramolecular cyclization because floppy ends tend to join up with another molecule rather than fold back on themselves. Girvin <jats:italic>et al.</jats:italic> identified a foldamer—a short, structured peptide—that can cyclize floppy, dialdehyde substrates through a templated aldol condensation (see the Perspective by Gutiérrez Collar and Gulder). Variation of the residues within the foldamer suggests that its helical structure helps position amine functional groups crucial for catalysis. The authors prepared molecules with a wide range of ring sizes and developed a synthesis for robustol, a macrocycle natural product with a 22-member ring. </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="6472" page="1528" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aax7344">1528</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6472" page="1454" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz9325">1454</jats:related-article> </jats:p>

<jats:title>VDACs are MOM's ruin</jats:title> <jats:p> Mitochondrial DNA (mtDNA) is normally kept within the mitochondria. It can be released into the cytosol in response to stress and thus encounter cytosolic DNA sensors, triggering type I interferon responses. During apoptosis, mtDNA release is mediated by macropores in the mitochondrial outer membrane (MOM) created by oligomerization of the proteins BAX and BAK. Kim <jats:italic>et al.</jats:italic> found that during oxidative stress, mtDNA escapes instead through macropores formed by oligomerization of voltage-dependent anion channels (VDACs) (see the Perspective by Crow). In a mouse model of lupus, an inhibitor of VDAC oligomerization diminished mtDNA release and downstream signaling events. This treatment reduced lupus-like symptoms in the model, suggesting a potential therapeutic route for conditions mediated by mtDNA release. </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="6472" page="1531" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aav4011">1531</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6472" page="1445" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz9308">1445</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>

<jats:p>The human immune system is a constant sentinel, seeking out unwelcome invaders in the body (viruses, bacteria, and the like) as well as nonself elements, including cancer and precancer cells. Tumor cells may use molecular mechanisms to evade discovery or to locally tamp down the immune system’s normal response. To counteract this end-run, researchers need a deep understanding of the complex relationships between different immune cells, and between these cells and their targets. This supplement introduces the reader to groundbreaking research in immuno-oncology, and offers a look at the latest cell analysis tools that are unlocking the secrets of immune cell relationships, potentially enabling future breakthroughs in immune-based therapies.</jats:p> <jats:p> This special supplement brought to you by the <jats:bold>Science</jats:bold> /AAAS Custom Publishing Office. </jats:p>

<jats:p>Through the study of structural biology we learn about life from the bottom up, starting at the atomic level. Drawing from research in biology, physics, chemistry, and engineering, this highly interdisciplinary field helps us to understand the fundamental mechanisms involved in the action and interaction of biological molecules. This supplement explores recent advances in structural biology to commemorate the 5th anniversary of the founding of the Beijing Advanced Innovation Center for Structural Biology (ICSB) at Tsinghua University. The ICSB faculty is tackling the most fundamental questions in biology, including deciphering the spliceosome, the complex protein machinery that splices RNA transcripts in preparation for translation into proteins; investigating G protein–coupled receptors, frequent targets for drugs; and characterizing γ-secretase, a protein implicated in Alzheimer's disease. We hope you enjoy this diverse and inspiring collection of articles, with its remarkable breadth of sophisticated technologies and biological paradigms.</jats:p> <jats:p> This special supplement brought to you by the <jats:bold>Science</jats:bold> /AAAS Custom Publishing Office. </jats:p>