Catálogo de publicaciones - revistas

<jats:title>Inflammasomes take the wheel</jats:title> <jats:p> Cells require microbial ligand binding to sense pathogens (see the Perspective by Liu and Xiao). Binding to the family of NOD-like receptors triggers the assembly of large protein signaling complexes called inflammasomes, leading infected cells to die and produce inflammatory mediators. Hu <jats:italic>et al.</jats:italic> and Zhang <jats:italic>et al.</jats:italic> use cryo–electron microscopy to uncover the structural and biochemical basis of two such receptors: NAIP2, which directly binds microbial ligands, and NLRC4, a protein functioning directly downstream. A self-propagating activation mechanism of downstream inflammasome signaling starts with one molecule of NAIP4 directly binding its microbial ligand. NAIP4 then catalyzes the activation of 10 to 12 NLRC4 molecules to form a wheel-like 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="6259" page="399" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac5489">399</jats:related-article> , <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6259" page="404" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac5789">404</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6259" page="376" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad3981">376</jats:related-article> </jats:p>

<jats:title>Inflammasomes take the wheel</jats:title> <jats:p> Cells require microbial ligand binding to sense pathogens (see the Perspective by Liu and Xiao). Binding to the family of NOD-like receptors triggers the assembly of large protein signaling complexes called inflammasomes, leading infected cells to die and produce inflammatory mediators. Hu <jats:italic>et al.</jats:italic> and Zhang <jats:italic>et al.</jats:italic> use cryo–electron microscopy to uncover the structural and biochemical basis of two such receptors: NAIP2, which directly binds microbial ligands, and NLRC4, a protein functioning directly downstream. A self-propagating activation mechanism of downstream inflammasome signaling starts with one molecule of NAIP4 directly binding its microbial ligand. NAIP4 then catalyzes the activation of 10 to 12 NLRC4 molecules to form a wheel-like 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="6259" page="399" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac5489">399</jats:related-article> , <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6259" page="404" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac5789">404</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6259" page="376" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad3981">376</jats:related-article> </jats:p>

<jats:title>A 3D approach to make 2D superconductors</jats:title> <jats:p> When the thickness of a superconducting film becomes comparable to the typical size of its electron pairs, its superconductivity enters a two-dimensional (2D) regime. Thinner films usually have higher amounts of disorder, making it difficult to isolate the 2D effects. To circumvent this limitation, Saito <jats:italic>et al.</jats:italic> induced charge carriers on the surface of the 3D insulator ZrNCl. This approach produced a clean superconducting layer thinner than the unit cell of the crystal. The superconducting state was extremely sensitive to the application of a perpendicular magnetic field, as expected for clean systems. </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="6259" page="409" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.1259440">409</jats:related-article> </jats:p>

<jats:title>Breaking chiral symmetry in a solid</jats:title> <jats:p> Dirac semimetals have graphene-like electronic structure, albeit in three rather than two dimensions. In a magnetic field, their Dirac cones split into two halves, one supporting left-handed and the other right-handed fermions. If an electric field is applied parallel to the magnetic field, this “chiral” symmetry may break: a phenomenon called the chiral anomaly. Xiong <jats:italic>et al.</jats:italic> observed this anomaly in the Dirac semimetal Na <jats:sub>3</jats:sub> Bi (see the Perspective by Burkov). Transport measurements lead to the detection of the predicted large negative magnetoresistance, which appeared only when the two fields were nearly parallel to each other. </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="6259" page="413" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac6089">413</jats:related-article> , see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6259" page="378" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad2713">378</jats:related-article> </jats:p>

<jats:title>EPR, one atom at a time</jats:title> <jats:p> Electron paramagnetic resonance (EPR) usually detects atoms with unpaired electrons as ensemble averages. Baumann <jats:italic>et al.</jats:italic> used a spin-polarized scanning tunneling microscope tip to measure EPR spectra of single iron atoms adsorbed on a magnesium oxide surface at cryogenic temperatures. The measurement depends on the atomic orbital symmetry; no signal was observed for cobalt atoms under the same 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="6259" page="417" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac8703">417</jats:related-article> </jats:p>

<jats:title>Probing the fluctuating vacuum</jats:title> <jats:p> According to quantum mechanics, a vacuum is not empty space. A consequence of the uncertainly principle is that particles or energy can come into existence for a fleeting moment. Such vacuum or quantum fluctuations are known to exist, but evidence for them has been indirect. Riek <jats:italic>et al.</jats:italic> present an ultrafast optical based technique that probes the vacuum fluctuation of electromagnetic radiation directly. </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="6259" page="420" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac9788">420</jats:related-article> </jats:p>

<jats:title>Stellar oscillations as magnetic probes</jats:title> <jats:p> Unlike magnetic fields on the surfaces of stars, those within a star have so far remained difficult to observe. Fuller <jats:italic>et al.</jats:italic> have developed a method of delving into the magnetic depths by exploiting the oscillations of red giant stars. A high magnetic field can cause sound waves to become trapped within the central regions of the star, damping certain vibration modes. Using seismological techniques, this suppression can help infer the core magnetic field for several red giants. </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="6259" page="423" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac6933">423</jats:related-article> </jats:p>

<jats:title>Multifunctional root regulators</jats:title> <jats:p> The growing plant root undergoes a variety of developmental steps that determine thickness and branching as the roots elaborate. Moreno-Risueno <jats:italic>et al.</jats:italic> identify a suite of transcription factors, some of which mobilize between cells, that regulate shifting fates during root growth. The same set of transcription factors governs identity and proliferation of the stem cells as well as the fates of daughter cells. </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="6259" page="426" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad1171">426</jats:related-article> </jats:p>