Catálogo de publicaciones - revistas

<jats:title>Plugging into the pump</jats:title> <jats:p> Photosynthetic organisms use light to fix carbon dioxide in a process that requires both chemical reducing equivalents and adenosine triphosphate (ATP). Balancing the ratio of these inputs is accomplished by a short circuit in electron flow through photosynthetic complex I, a proton pump that contributes to ATP production but does not increase net reducing equivalents in the cell. Schuller <jats:italic>et al.</jats:italic> solved a cryo–electron microscopy structure of photosynthetic complex I (see the Perspective by Brandt) and went on to reconstitute electron transfer using the electron carrier protein ferredoxin. </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="6424" page="257" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aau3613">257</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6424" page="230" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aaw0493">230</jats:related-article> </jats:p>

<jats:title>Brief get-togethers between NaK and K</jats:title> <jats:p> Cooling molecules to nanokelvin temperatures places them under the tightest quantum mechanical constraints. Studies in this intriguing regime have been limited to diatomics: Two cold atoms can be lured together into weakly associated Feshbach resonances, which lasers can then shift into a more stable molecular state. Yang <jats:italic>et al.</jats:italic> now report the observation of triatomic Feshbach resonances in ultracold collisions between potassium (K) atoms and sodium potassium (NaK) diatomics. The findings potentially set the stage for the preparation and study of ultracold triatomic molecules. </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="6424" page="261" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aau5322">261</jats:related-article> </jats:p>

<jats:title>A redox road to recovery</jats:title> <jats:p> Device longevity is a key issue for organic-inorganic perovskite solar cells. Encapsulation can limit degradation arising from reactions with oxygen and water, but light, electric-field, and thermal stresses can lead to metastable elemental lead and halide atom defects. Wang <jats:italic>et al.</jats:italic> show that for the lead-iodine system, the introduction of the rare earth europium ion pair Eu <jats:sup>3+</jats:sup> -Eu <jats:sup>2+</jats:sup> can shuttle electrons and recover lead and iodine ions (Pb <jats:sup>2+</jats:sup> and I <jats:sup>−</jats:sup> ). Devices incorporating this redox shuttle maintained more than 90% of their initial power conversion efficiencies under various aging 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="6424" page="265" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aau5701">265</jats:related-article> </jats:p>

<jats:title>Journey to jorumycin</jats:title> <jats:p> Jorumycin is a structurally complex, pentacyclic organic compound produced by a marine mollusk. The success of a similar compound, trabectedin, in treating certain types of cancer has focused attention on exploring jorumycin's pharmaceutical properties. Welin <jats:italic>et al.</jats:italic> developed a succinct route to synthesizing jorumycin and the closely related jorunnamycin A that deliberately diverges from the putative biosynthetic pathway underlying prior chemical syntheses. This route, which hinges on a carefully optimized asymmetric catalytic hydrogenation, can be easily modified to introduce unnatural structural diversity for functional optimization in further drug discovery research. </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="6424" page="270" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aav3421">270</jats:related-article> </jats:p>

<jats:title>The emotional dimension of pain</jats:title> <jats:p> The unpleasantness of pain is an emotional phenomenon distinct from pain's sensory qualities. To study how the brain processes pain-related emotions, Corder <jats:italic>et al.</jats:italic> used in vivo neural calcium imaging in freely behaving mice. They identified brain circuits that respond to pain and directly tested their causal role in motivational behaviors associated with acute and chronic pain. </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="6424" page="276" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aap8586">276</jats:related-article> </jats:p>

<jats:title>Ancestral history matters</jats:title> <jats:p> Biodiversity is sometimes quantified purely by the number of species within a system that allow it to function to produce ecosystem services. Grab <jats:italic>et al.</jats:italic> show that simple species counting is too simplistic. They combined remotely sensed land-cover analyses and crop production records with an extensive 10-year pollinator community survey and a complete species-level phylogeny generated using genome-wide phylogenomic methods. They found that the equivalent of millions of years of pollinator evolution were lost in highly altered agricultural environments, which decreased pollination services above and beyond what would be expected from a simple numerical species count. </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="6424" page="282" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aat6016">282</jats:related-article> </jats:p>

<jats:title>Assembly of the ciliary microtubule doublet</jats:title> <jats:p> The cilium is a conserved organelle that is crucial for motility as well as for sensing the extracellular environment. Its core structure is characterized by nine microtubule doublets (MTDs). The mechanisms of MTD assembly are unclear. Schmidt-Cernohorska <jats:italic>et al.</jats:italic> developed an assay to reconstitute MTD assembly in vitro. Tubulin carboxyl-terminal tails played a critical inhibitory role in MTD formation. Molecular dynamics revealed that carboxyl-terminal tails of the A11 microtubule protofilament regulated MTD initiation. Furthermore, live-cell imaging showed an unexpected bidirectional isotropic elongation of the MTD. </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="6424" page="285" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aav2567">285</jats:related-article> </jats:p>

<jats:title>Serotherapy treats a transplant hurdle</jats:title> <jats:p> Cytomegalovirus (CMV) infection and reactivation are common and potentially fatal complications after bone marrow or hematopoietic stem cell transplantation (BMT). Martins <jats:italic>et al.</jats:italic> developed faithful preclinical murine models of CMV reactivation following BMT and found that humoral immunity can prevent this process (see the Perspective by Alegre). After BMT, antiviral antibodies that would have kept CMV at bay dwindle because host plasma cells are ablated and the donor B cell pool reconstitutes poorly. CMV reactivation was prevented by transferring antibody-containing immune serum. Such a therapeutic strategy would avoid some limitations of cellular therapies for BMT patients. </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="6424" page="288" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aat0066">288</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6424" page="232" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aav9867">232</jats:related-article> </jats:p>

<jats:title>Reversing chromatin dynamics for development</jats:title> <jats:p> Compacted chromatin regions, marked by trimethylation of histone H3 at position lysine 9 (H3K9me3), occur at highly repeated DNA sequences, helping to suppress recombination and gene expression. Because pluripotent cells contain low levels of H3K9me3 heterochromatin relative to differentiated cells, it has been thought that an increase in such heterochromatin helps to define cell differentiation. Nicetto <jats:italic>et al.</jats:italic> used two independent methods to examine compacted heterochromatic domains and found that H3K9me3 compaction increased at protein-coding genes during early mouse organogenesis. During differentiation, these domains open up to allow cell-specific expression. Loss of heterochromatin by genetic inactivation of the H3K9me3 methyltransferases caused ectopic expression of cell-inappropriate genes and tissue pathology. </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="6424" page="294" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aau0583">294</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>