Catálogo de publicaciones - revistas

<jats:title>Transistor sensing in salt solutions</jats:title> <jats:p> Molecular binding to receptors on the surface of field-effect transistors (FETs) can be sensed through changes in transconductance. However, the saline solutions typically used with biomolecules create an electrical double layer that masks any events that occur within about 1 nanometer from the surface. Nakatsuka <jats:italic>et al.</jats:italic> overcame this limitation by using binding to large, negatively charged DNA stem loop structures that, upon ligand binding, cause conformational changes that can be sensed with an FET, even in solutions with high ionic strength. The authors demonstrate the sensing of charged molecules such as dopamine in artificial cerebrospinal fluid as well as neutral molecules such as glucose and zwitterion molecules like sphingosine-1-phosphate. </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="6412" page="319" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aao6750">319</jats:related-article> </jats:p>

<jats:title>Thickness matters in graphene stacks</jats:title> <jats:p> If you stack graphene monolayers on top of each other, the number of layers will affect the properties of the material. Intuitively, one would expect that as the stack becomes thicker, the results will converge as the sample starts to resemble graphite. Nam <jats:italic>et al.</jats:italic> measured the conductance of graphene multilayers of increasing thickness. Studying samples up to seven layers thick, they found that in all of them, electronic correlations caused a phase transition at a nonzero critical temperature. However, the critical temperature, as well as the nature of the low-temperature state, depended strongly on the number of layers. This unexpectedly persistent dependence showed no signs of slowing down and will motivate further theoretical and experimental work. </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="6412" page="324" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aar6855">324</jats:related-article> </jats:p>

<jats:title>A solid and squishy inner core</jats:title> <jats:p>Earth's inner core is thought to be solid, which means it should support shear waves. However, the small size of the inner core makes detecting shear waves very difficult. Tkalčić and Phạm correlated different types of seismic phases to finally determine the speed of shear waves in Earth's inner core (see the Perspective by Irving). The detection of the waves closes an 80-year quest to find them and confirms a solid, but soft, inner core.</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="6412" page="329" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aau7649">329</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6412" page="294" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav2296">294</jats:related-article> </jats:p>

<jats:title>An iron home for Majoranas</jats:title> <jats:p> The surface of the iron-based superconductor FeTe <jats:sub>0.55</jats:sub> Se <jats:sub>0.45</jats:sub> has been identified as a potential topological superconductor and is expected to host exotic quasiparticles called the Majorana bound states (MBSs). Wang <jats:italic>et al.</jats:italic> looked for signatures of MBSs in this material by using scanning tunneling spectroscopy on the vortex cores formed by the application of a magnetic field. In addition to conventional states, they observed the characteristic zero-bias peaks associated with MBSs and were able to distinguish between the two, owing to the favorable ratios of energy scales in the system. </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="6412" page="333" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aao1797">333</jats:related-article> </jats:p>

<jats:title>Hyperfine spectra of surface atoms</jats:title> <jats:p> The interaction of nuclei with nonzero spin with electron spins creates small electronic energy. With a scanning tunneling microscope tip, Willke <jats:italic>et al.</jats:italic> measured these hyperfine interactions for iron and titanium atoms that were manipulated on a magnesium oxide surface. The tip was also used to measure electron paramagnetic resonance spectra. The hyperfine structure of single atoms was sensitive to the binding site of the atom as well as its position relative to other magnetic atoms. </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="6412" page="336" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat7047">336</jats:related-article> </jats:p>

<jats:title>Supracellular cable drives collective cell movement</jats:title> <jats:p> Neural crest cells migrate far and wide through a vertebrate embryo during development. Shellard <jats:italic>et al.</jats:italic> used <jats:italic>Xenopus</jats:italic> and zebrafish embryos to study how these clumps of mesenchymal cells migrate (see the Perspective by Adameyko). Movement was powered by a supracellular actomyosin cable that contracted around the rear of the clump. Similar supracellular contractility at the front was inhibited by a chemotactic signal. The imbalance in forces caused cells to rearrange so that the whole clump would be propelled forward. </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="6412" page="339" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aau3301">339</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6412" page="290" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav3376">290</jats:related-article> </jats:p>

<jats:title>Poppy genome reveals evolution of opiates</jats:title> <jats:p> The opium poppy has been a source of painkillers since Neolithic times. Attendant risks of addiction threaten many today. Guo <jats:italic>et al.</jats:italic> now deliver a draft of the opium poppy genome, which encompasses 2.72 gigabases assembled into 11 chromosomes and predicts more than 50,000 protein-coding genes. A particularly complex gene cluster contains many critical enzymes in the metabolic pathway that generates the alkaloid drugs noscapine and morphinan. </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="6412" page="343" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat4096">343</jats:related-article> </jats:p>

<jats:title>Sharing pharmaceutical research</jats:title> <jats:p> Increased collaboration will enhance our ability to predict new therapeutic drug candidates. Such data sharing is currently limited by concerns about intellectual property and competing commercial interests. Hie <jats:italic>et al.</jats:italic> introduce an end-to-end pipeline, using modern cryptographic tools, for secure pharmacological collaboration. Multiple entities can thus securely combine their private datasets to collectively obtain more accurate predictions of new drug-target interactions. The computational pipeline is practical, producing results with improved accuracy in a few days over a wide area network on a real dataset with more than a million interactions. </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="6412" page="347" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat4807">347</jats:related-article> </jats:p>

<jats:title>The absence of DNGR-1 is dangerous</jats:title> <jats:p> Conventional type 1 dendritic cells (cDC1s) can sense tissue damage via DNGR-1, which binds F-actin exposed by necrotic cells. DNGR-1 activation favors cross-presentation, the process by which extracellular antigens are processed and presented to CD8 <jats:sup>+</jats:sup> T cells via major histocompatibility complex class I molecules. Del Fresno <jats:italic>et al.</jats:italic> studied mice lacking DNGR-1 and found that DNGR-1 also has anti-inflammatory effects (see the Perspective by Salazar and Brown). It inhibits the secretion of the chemokine CXCL2 by cDC1s, which, in turn, limits neutrophil recruitment. Thus, DNGR-1 connects cell-death sensing with a mechanism of damage control. </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="6412" page="351" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aan8423">351</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6412" page="292" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav3477">292</jats:related-article> </jats:p>

<jats:title>Reconstituting a human ovary</jats:title> <jats:p> Human pluripotent stem cells (hPSCs) have been induced into human primordial germ cell–like cells (hPGCLCs) in vitro, the first step toward human in vitro gametogenesis. Yamashiro <jats:italic>et al.</jats:italic> went a step closer to generating mature gametes by culturing hPSCs with mouse embryonic ovarian somatic cells in xenogeneic reconstituted ovaries (see the Perspective by Gill and Peters). Over a period of 4 months, hPGCLCs underwent hallmark epigenetic reprogramming and differentiated progressively into cells closely resembling human oogonia, an immediate embryonic precursor for human oocytes. This study creates opportunities for human germ cell research and provides a foundation for human in vitro gametogenesis. </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="6412" page="356" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat1674">356</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6412" page="291" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav3479">291</jats:related-article> </jats:p>