Catálogo de publicaciones - revistas

<jats:title>Evolutionary dynamics in hematopoiesis</jats:title> <jats:p> Cells accumulate mutations as we age, and these mutations can be a source of diseases such as cancer. How cells containing mutations evolve, are maintained, and proliferate within the body has not been well characterized. Using a quantitative framework, Watson <jats:italic>et al.</jats:italic> applied population genetic theory to estimate mutation accumulation in cells in blood from sequencing data derived from nearly 50,000 healthy individuals (see the Perspective by Curtis). By evaluating how mutations differ between blood cell populations, a phenomenon known as clonal hematopoiesis, the researchers could observe how recurrent mutations can drive certain clonal lineages to high frequencies within an individual. The risk of specific mutations, some of which are associated with leukemias, rising to high frequencies may therefore be a function of cellular selection and the age at which the mutation originated. </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="6485" page="1449" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay9333">1449</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6485" page="1426" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba9891">1426</jats:related-article> </jats:p>

<jats:title>A resilient superconductor</jats:title> <jats:p> Superconductivity typically does not fare well in the presence of magnetic fields, which tend to break the electron pairs that make a material superconducting. However, some materials, such as the recently discovered Ising superconductors, retain their properties in very high magnetic fields. Ising pairing was identified in transition metal dichalcogenides such as molybdenum disulfide and required the breaking of inversion symmetry. Falson <jats:italic>et al.</jats:italic> have now found a similar resilience to in-plane magnetic fields in another two-dimensional material, few-layer stanene. The band structure of stanene and the lack of inversion symmetry breaking in the system required a distinct theoretical model to explain this property, now dubbed type II Ising pairing. </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="6485" page="1454" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aax3873">1454</jats:related-article> </jats:p>

<jats:title>Precision spectroscopy with single ions</jats:title> <jats:p> Spectroscopy is a powerful tool that can identify chemical species used in a wide range of settings. Usually, the samples are formed of ensembles, and this can limit the resolution with which the different species can be detected or identified. Chou <jats:italic>et al.</jats:italic> demonstrate an optical frequency comb technique with a single pair of trapped ions, Ca <jats:sub>+</jats:sub> and CaH <jats:sub>+</jats:sub> , to obtain the rotational spectrum of a single trapped ion, CaH <jats:sub>+</jats:sub> . With the ions isolated and the ensemble interactions removed, the rotational structure of the trapped molecular ion can then be obtained with high precision. As the trapping and manipulation process is general, this technique could be applied to a number of chemical species for specific purposes. </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="6485" page="1458" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba3628">1458</jats:related-article> </jats:p>

<jats:title>Capturing the transformation</jats:title> <jats:p> Quantum statistics dictates the behavior of identical particles in the quantum world: Bosons like to congregate, whereas fermions avoid one another. However, strong interactions can cause a string of bosons to behave like fermions. This so-called fermionization phenomenon has been studied in equilibrium. Wilson <jats:italic>et al.</jats:italic> instead focused on dynamical fermionization in a nonequilibrium system consisting of tubes of strongly interacting bosonic rubidium atoms. After letting the tubes expand in the axial direction, the researchers monitored the momentum distribution of the atoms and found that it evolved from bosonic-like to fermionic-like. </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="6485" page="1461" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz0242">1461</jats:related-article> </jats:p>

<jats:title>X-ray data constrain dark matter decay</jats:title> <jats:p> Dark matter may consist of previously unknown forms of subatomic particles. An unidentified astronomical x-ray emission line has been interpreted as being caused by the decay of a dark matter particle. If this is correct, then dark matter in the halo of the Milky Way Galaxy should produce a faint emission line across the whole sky. Dessert <jats:italic>et al.</jats:italic> tested this hypothesis using observations by the XMM-Newton (X-ray Multi-Mirror Mission) space telescope. Analyzing blank-sky regions with a total exposure time of about a year, they found no evidence for the predicted line and set upper limits on the decay rate that rule out the previously proposed dark matter interpretation. </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="6485" page="1465" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaw3772">1465</jats:related-article> </jats:p>

<jats:title>Metastasis: A matter of translation?</jats:title> <jats:p> Solid tumors shed a small number of cancer cells into the bloodstream, some of which are believed to contribute to metastasis. The molecular features that confer these circulating tumor cells (CTCs) with metastatic potential are poorly understood. Ebright <jats:italic>et al.</jats:italic> studied CTCs from breast cancer patients and found that cells with increased expression levels of certain ribosomal proteins and regulators of translation had greater metastatic capacity in a mouse model (see the Perspective by Ma and Jeffrey). Consistent with this finding, patients with higher levels of this subset of CTCs tended to have a poorer prognosis. </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="6485" page="1468" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay0939">1468</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6485" page="1424" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.abb0736">1424</jats:related-article> </jats:p>

<jats:title>Glassy metal-organic frameworks</jats:title> <jats:p> The node-and-linker structure of metal-organic frameworks could enable detailed structural studies of molecular glasses quenched from melts. Zinc-based zeolitic imidazole frameworks exhibit a high propensity for glass formation at conventional cooling rates. Madsen <jats:italic>et al.</jats:italic> used ultrahigh magnetic fields (19.5 and 35.2 tesla) to perform zinc-67 nuclear magnetic resonance of solid samples with magic-angle spinning on three samples with different ratios of imidazole and benzimidazole linkers. The structural disorder of the tetrahedral ligand environment around zinc nodes was higher in the glassy states than in the parent crystals. </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="6485" page="1473" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz0251">1473</jats:related-article> </jats:p>

<jats:title>Not a big deal after all</jats:title> <jats:p> Do volcanic eruptions affect El Niño–Southern Oscillation (ENSO) variability? Models indicate that sulfate aerosols resulting from large eruptions can initiate an El Niño–like response in the tropical Pacific, but observations have not shown evidence of such behavior. Dee <jats:italic>et al</jats:italic> . present an oxygen-isotope time series of fossil corals from the central tropical Pacific to investigate ENSO's response to large volcanic eruptions during the past millennium. They found a weak tendency for an El Niño–like response in the year after an eruption, but not one that was statistically significant. These results suggest that large volcanic events have not triggered a detectable response in ENSO over the past thousand years and that their impact is small relative to the degree of natural variability. </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="6485" page="1477" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aax2000">1477</jats:related-article> </jats:p>

<jats:title>Fruit abscission in response to drought</jats:title> <jats:p> Plants faced with drought, or simply not quite enough water, may be more likely to drop their fruit prematurely. Reichardt <jats:italic>et al.</jats:italic> found that a small signaling peptide hormone, phytosulfokine, which was previously known for its ability to regulate plant cell growth, also drives fruit abscission. Processed, and thus activated, by a subtilisin-like protease, phytosulfokine in turn drives expression of the hydrolases that degrade the cell walls in the abscission zone, leading to dropped fruit. </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="6485" page="1482" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz5641">1482</jats:related-article> </jats:p>

<jats:title>Disrupting deep circulation</jats:title> <jats:p> Atlantic Meridional Overturning Circulation (AMOC) and the related process of North Atlantic Deep Water (NADW) have been thought to be stable during warm, interglacial periods. Galaasen <jats:italic>et al.</jats:italic> report that episodes of reduced NADW over the past 500,000 years actually have been relatively common and occasionally long-lasting features of interglacials and that they can occur independently of the catastrophic freshwater outburst floods normally thought to be their cause (see the Perspective by Stocker). This discovery implies that large NADW disruptions might be more likely than we have assumed in the warmer climate of the future. </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="6485" page="1485" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay6381">1485</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6485" page="1425" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.abb3569">1425</jats:related-article> </jats:p>