Catálogo de publicaciones - revistas

<jats:title>A million times cooler</jats:title> <jats:p> Elastocaloric materials can be used for solid-state cooling applications because they can pump heat out of a system using a reversible phase transformation. However, many such materials fail after a small number of cycles. Hou <jats:italic>et al.</jats:italic> found that laser melting of elastocaloric metals can create fatigue-resistant microstructures. A nickel-titanium–based alloy could be cycled a million times and still produce a cooling of about 4 kelvin. This processing method could improve elastocaloric performance and move us closer to using these materials more widely for solid-state cooling 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="6469" page="1116" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aax7616">1116</jats:related-article> </jats:p>

<jats:title>Toward magnonic devices</jats:title> <jats:p> The field of magnonics aims to use spin waves (SWs) and their associated quasiparticles—magnons—as carriers of information. Compared with the movement of charge in conventional electronics, a major advantage of SWs is reduced Joule heating. However, SWs are trickier to direct and control. Two groups now go a step further toward magnon-based devices. Han <jats:italic>et al.</jats:italic> show that in multilayer films, domain walls can be used to change the phase and magnitude of a spin wave. Wang <jats:italic>et al.</jats:italic> demonstrate how magnon currents can be used to switch the magnetization of an adjacent layer. </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="6469" page="1121" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aau2610">1121</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6469" page="1125" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aav8076">1125</jats:related-article> </jats:p>

<jats:title>Toward magnonic devices</jats:title> <jats:p> The field of magnonics aims to use spin waves (SWs) and their associated quasiparticles—magnons—as carriers of information. Compared with the movement of charge in conventional electronics, a major advantage of SWs is reduced Joule heating. However, SWs are trickier to direct and control. Two groups now go a step further toward magnon-based devices. Han <jats:italic>et al.</jats:italic> show that in multilayer films, domain walls can be used to change the phase and magnitude of a spin wave. Wang <jats:italic>et al.</jats:italic> demonstrate how magnon currents can be used to switch the magnetization of an adjacent layer. </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="6469" page="1121" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aau2610">1121</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6469" page="1125" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aav8076">1125</jats:related-article> </jats:p>

<jats:title>CTP hydrolysis organizes chromosomes</jats:title> <jats:p> The bacterial DNA <jats:italic>parS</jats:italic> centromere recruits the ParB protein to the bacterial chromosome. Soh <jats:italic>et al.</jats:italic> found that the widespread family of ParB proteins not only bind DNA but also bind and hydrolyze cytidine triphosphate (CTP) (see the Perspective by Funnell). ParB CTP hydrolysis is stimulated by <jats:italic>parS</jats:italic> and regulates the spreading of ParB protein to the <jats:italic>parS</jats:italic> flanking regions, which is crucial for organizing the bacterial chromosome. The cytidine triphosphatase domain is conserved in a large variety of protein sequences, suggesting its potential roles in other cellular processes. </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="6469" page="1129" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aay3965">1129</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6469" page="1072" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz8632">1072</jats:related-article> </jats:p>

<jats:title>Linking enhancers to disease</jats:title> <jats:p> Enhancers are genomic regions that regulate gene expression, sometimes in a cell-dependent manner. However, most of our knowledge of human brain cell–type enhancers derives from studies of bulk human brain tissue. Nott <jats:italic>et al.</jats:italic> examined chromatin and promoter activity in cell nuclei isolated from human brains. Genetic variants associated with brain traits and disease showed cell-specific patterns of enhancer enrichment. These data indicate that Alzheimer's disease is regulated by genetic variants within microglial cells, whereas psychiatric diseases tend to affect neurons. </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="6469" page="1134" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aay0793">1134</jats:related-article> </jats:p>

<jats:title>The fitness landscape of AAV</jats:title> <jats:p> Adeno-associated virus (AAV) is an important gene therapy vector. Using tools from synthetic biology, Ogden <jats:italic>et al.</jats:italic> provide a comprehensive view of how sequence changes in capsid proteins affect AAV properties. After saturation mutagenesis of the AAV2 capsid gene, the resulting library was subjected to multiplexed phenotypic analyses, including virus production, immunity, thermostability, and biodistribution. The mutant distribution to major organs in mice revealed dominant trends affecting in vivo delivery. Moreover, the findings uncovered a viral accessory protein with a role in viral production. Finally, a model built from the capsid fitness landscape enabled machine-guided design of useful variants with much higher efficiency than random mutagenesis. </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="6469" page="1139" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaw2900">1139</jats:related-article> </jats:p>

<jats:title>Lactose can fuel GVHD</jats:title> <jats:p> Allogeneic hematopoietic cell transplantation (allo-HCT) is used to treat certain hematopoietic malignancies, but patients have a risk of developing graft-versus-host disease (GVHD). Stein-Thoeringer <jats:italic>et al.</jats:italic> performed a large-scale analysis of more than 1300 patients treated with allo-HCT across four clinical centers (see the Perspective by Zitvogel and Kroemer). High levels of bacteria from the <jats:italic>Enterococcus</jats:italic> genus were associated with greater incidence of GVHD and mortality. Lactose appears to provide a substrate for <jats:italic>Enterococcus</jats:italic> growth, and patients with a lactose-malabsorption genotype had a greater abundance of <jats:italic>Enterococcus.</jats:italic> A lactose-free diet limited <jats:italic>Enterococcus</jats:italic> growth, reduced the severity of GVHD, and improved survival in gnotobiotic mouse models. </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="6469" page="1143" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aax3760">1143</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6469" page="1077" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz7595">1077</jats:related-article> </jats:p>

<jats:title>A pathway for helical membrane proteins</jats:title> <jats:p> Membrane proteins are inserted into cell membranes while they are being translated and may fold concurrently into their secondary and tertiary structures. Choi <jats:italic>et al.</jats:italic> describe a single-molecule force microscopy technique that allowed them to monitor folding of helical membrane proteins in vesicles and bicelles. Two helical membrane proteins, the <jats:italic>Escherichia coli</jats:italic> rhomboid protease GlpG and the human β <jats:sub>2</jats:sub> -adrenergic receptor, both folded from the N to the C terminus, with structures forming in units of helical hairpins. In the cell, this would allow these proteins to begin folding while being translated. </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="6469" page="1150" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaw8208">1150</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>