Catálogo de publicaciones - revistas

<jats:p>A metathesis reaction yields a strategy to cross-link and enhance polymers without compromising easy processing and recycling.</jats:p>

<jats:title>A mantle story told with metal and gas</jats:title> <jats:p> Differences in isotopic compositions of trace elements can help identify how regions of Earth's mantle have evolved over time. Mundl <jats:italic>et al.</jats:italic> identified several ancient domains that have been isolated from mantle homogenization and thus contain signatures of primordial material. Tungsten and helium isotope values indicate fractionation and isolation of these mantle domains just after Earth's formation. The findings help constrain ancient processes such as core formation, but also provide insight into unexplained structures in the lower mantle today. </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="6333" page="66" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aal4179">66</jats:related-article> </jats:p>

<jats:title>Printing nanosheet-network transistors</jats:title> <jats:p> Two-dimensional (2D) materials such as graphene and metal chalcogenides such as tungsten diselenide (WSe2) are attractive for use in low-cost thin-film transistors (TFTs) because they have high charge-carrier mobility. Kelly <jats:italic>et al.</jats:italic> printed TFTs from networks of exfoliated dispersions of 2D materials with graphene contacts, WSe <jats:sub>2</jats:sub> as the semiconductor, and a boron nitride separator. Electrolytic gating with ionic liquids enabled higher operating currents than achieved with comparable organic TFTs. </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="6333" page="69" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aal4062">69</jats:related-article> </jats:p>

<jats:p>The representation of contextual fear memories evolves over time in the hippocampus, amygdala, and prefrontal cortex.</jats:p>

<jats:p>For biomedical patents, basic research is just as valuable as applied research.</jats:p>

<jats:p>Viral evolution is revealed by giant viruses encoding multiple components of the protein translation machinery.</jats:p>

<jats:title>DNA sequence and inherited gene silencing</jats:title> <jats:p> Cell fate decisions require a gene's transcriptional status, whether on or off, to be stably and heritably maintained over multiple cell generations. For silenced genes, heterochromatin domains are associated with specific histone posttranslational modifications, and these histone marks are maintained during DNA replication and chromosome duplication (see the Perspective by De and Kassis). Laprell <jats:italic>et al.</jats:italic> show that parental methylated histone H3 lysine 27 (H3K27) nucleosomes in <jats:italic>Drosophila</jats:italic> are inherited in daughter cells after replication and can repress transcription, but that they are not sufficient to propagate the mark. Trimethylation of newly incorporated nucleosomes requires recruitment of the methyltransferase Polycomb repressive complex 2 (PRC2) to neighboring cis-regulatory DNA elements. Coleman and Struhl demonstrate that H3K27 trimethylated nucleosomes play a causal role in transmitting epigenetic memory at a <jats:italic>Drosophila</jats:italic> HOX gene through anchoring of PRC2 at the Polycomb response element binding site. Wang and Moazed examine fission yeast and show that both sequence-dependent and chromodomain sequence-independent mechanisms are required for stable epigenetic inheritance of histone modifications and the epigenetic maintenance of silencing. These studies highlight the crucial role of DNA binding for heritable gene silencing during growth and development. </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="6333" page="85" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aai8266">85</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6333" page="eaai8236" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aai8236">eaai8236</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6333" page="88" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aaj2114">88</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6333" page="28" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aan1493">28</jats:related-article> </jats:p>

<jats:title>DNA sequence and inherited gene silencing</jats:title> <jats:p> Cell fate decisions require a gene's transcriptional status, whether on or off, to be stably and heritably maintained over multiple cell generations. For silenced genes, heterochromatin domains are associated with specific histone posttranslational modifications, and these histone marks are maintained during DNA replication and chromosome duplication (see the Perspective by De and Kassis). Laprell <jats:italic>et al.</jats:italic> show that parental methylated histone H3 lysine 27 (H3K27) nucleosomes in <jats:italic>Drosophila</jats:italic> are inherited in daughter cells after replication and can repress transcription, but that they are not sufficient to propagate the mark. Trimethylation of newly incorporated nucleosomes requires recruitment of the methyltransferase Polycomb repressive complex 2 (PRC2) to neighboring cis-regulatory DNA elements. Coleman and Struhl demonstrate that H3K27 trimethylated nucleosomes play a causal role in transmitting epigenetic memory at a <jats:italic>Drosophila</jats:italic> HOX gene through anchoring of PRC2 at the Polycomb response element binding site. Wang and Moazed examine fission yeast and show that both sequence-dependent and chromodomain sequence-independent mechanisms are required for stable epigenetic inheritance of histone modifications and the epigenetic maintenance of silencing. These studies highlight the crucial role of DNA binding for heritable gene silencing during growth and development. </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="6333" page="85" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aai8266">85</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6333" page="eaai8236" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aai8236">eaai8236</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6333" page="88" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aaj2114">88</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6333" page="28" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aan1493">28</jats:related-article> </jats:p>

<jats:title>Hi-C for mosquito genomes</jats:title> <jats:p> Most genomes sequenced today are determined through the generation of short sequenced bits of DNA that are computationally pieced together like a jigsaw puzzle. This has resulted in the need for funds and additional data to fill in gaps in order to fully assemble the many chromosomes that make up a eukaryotic genome. Dudchenko <jats:italic>et al.</jats:italic> used the Hi-C method, which measures the distance between contact points within and between chromosomes for scaffold validation, together with correction and ordering to more completely determine the arrangement of short sequencing reads for genome mapping. They validated their approach through the de novo generation of a complete human genome. A comparative analysis of mosquito genomes was made possible by improving the <jats:italic>Culex quinquefasciatus</jats:italic> genome assembly and generating the genome of <jats:italic>Aedes aegypti</jats:italic> , the vector of Zika virus. </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="6333" page="92" related-article-type="in-this-issue" vol="356" xlink:href="10.1126/science.aal3327">92</jats:related-article> </jats:p>

<jats:p> The jump from two dimensions to three gives researchers a laboratory model that is just one step removed from working with cells in vivo. Technologies and techniques have recently proliferated—such as matrices, scaffolds, and other geometries—to coax cells to grow in a wide array of 3D structures. <jats:list list-type="bullet"> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/custom-publishing/technology-features/adding-depth-cell-culture">Read the Feature (Full-Text HTML)</jats:ext-link> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/sites/default/files/custom-publishing/documents/7AprilCellCultureFeature_4-24-2017_2.pdf">Read the Feature (PDF)</jats:ext-link> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/sites/default/files/custom-publishing/douments/7AprilNewProducts.pdf">Read New Products (PDF)</jats:ext-link> </jats:p> </jats:list-item> </jats:list> </jats:p>