Catálogo de publicaciones - revistas

<jats:title>Brain synapses through the life span</jats:title> <jats:p> Excitatory synapses connect neurons in the brain to build the circuits that enable behavior. Cizeron <jats:italic>et al.</jats:italic> surveyed synapses in the mouse brain from birth to old age and present the data as a community resource, the Mouse Lifespan Synaptome Atlas (see the Perspective by Micheva <jats:italic>et al.</jats:italic> ). Molecular and morphological features defined 37 subtypes of synapses. Although synapse density generally increased in early development and declined in old age, the details differed in different brain areas. </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="6501" page="270" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba3163">270</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6501" page="253" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc9555">253</jats:related-article> </jats:p>

<jats:title>Ironing out a survival strategy</jats:title> <jats:p> Metastatic cells display a notable ability to adapt to—and even thrive in—harsh microenvironments. One extreme example is leptomeningeal metastases (LM), cancer cells that enter a region of the central nervous system called the subarachnoid space, which is filled with cerebral spinal fluid (CSF). This anatomic site has a limited supply of micronutrients such as iron, and it harbors immune cells. Chi <jats:italic>et al.</jats:italic> used single-cell RNA sequencing to study CSF samples from cancer patients with LM (see the Perspective by Garzia and Taylor). They found that LM cells express and use components of a high-affinity iron-capturing system. Through this mechanism, the LM cells avoid the adverse effects of iron deprivation and potentially escape immune attack by limiting the supply of iron to macrophages. </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="6501" page="276" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz2193">276</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6501" page="250" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb7041">250</jats:related-article> </jats:p>

<jats:title>A genetic history of China</jats:title> <jats:p> The history of human movements into and within China has been difficult to determine solely from archaeological investigations or genetic studies of contemporary peoples. Yang <jats:italic>et al.</jats:italic> sequenced DNA from 26 individuals from 9500 to 300 years ago from locations within China. Analyses of these individuals, along with previously sequenced ancient individuals and present-day genomes representing global populations, show a split between ancient humans in northern and southern China. Neolithic northern Chinese individuals are closest to modern-day East Asians, whereas ancient individuals from southern China are most closely related to modern-day Southeast Asians and show an affinity to modern-day Austronesian populations. These results indicate that there was a southward movement and admixture of peoples during the Neolithic that gave rise to modern-day populations in East Asia. </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="6501" page="282" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba0909">282</jats:related-article> </jats:p>

<jats:title>Liquid-liquid critical point of water</jats:title> <jats:p> Despite a broad range of experimental observations that indirectly point out the possible existence of a liquid-liquid phase transition in deeply supercooled water, no unambiguous experiment has shown this yet. The challenges of performing experiments under such conditions are associated with the inevitable rapid crystallization of the metastable liquid state, and therefore computational simulations become a crucial alternative. Using two accurate classical models of water and long (more than 40 microseconds) isobaricisothermal molecular dynamics simulations, Debenedetti <jats:italic>et al.</jats:italic> provide strong computational evidence of the presence of a second metastable liquid-liquid critical point in the deeply supercooled region that has critical behavior consistent with the three-dimensional Ising universality class. </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="6501" page="289" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb9796">289</jats:related-article> </jats:p>

<jats:title>Simple strain enhancement</jats:title> <jats:p> Piezoelectric materials are important as sensors and transducers for applications such as ultrasonics. Liu <jats:italic>et al.</jats:italic> discovered nanopillar regions in a sodium-niobium-oxide film that substantially improve the piezoelectric properties (see the Perspective by Bassiri-Gharb). These nanopillar regions reverse where the cations and anions are located in the crystal structure, with a distinctive boundary in between. This difference in structure results in a strain-sensitive polarity that enhances the piezoelectric properties in a chemically simple material. </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="6501" page="292" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb3209">292</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6501" page="252" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc8007">252</jats:related-article> </jats:p>

<jats:title>Blighted Gotham</jats:title> <jats:p> Deaths caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in New York City (NYC) during the spring of 2020 have vastly exceeded those reported in China and many other countries. What were the early events that led to such a severe outbreak? Gonzalez-Reiche <jats:italic>et al.</jats:italic> sampled some of the early patients seeking assistance in February and March of 2020 at the Mount Sinai Health System. Phylogenetic analysis of virus sequences in these people, who were drawn from across NYC, showed that the virus had been independently introduced many times from Europe and elsewhere in the United States. Subsequent clusters of community transmission occurred. The focus of infection in NYC is a marker of the role this city plays as a two-way hub for human movement. </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="6501" page="297" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc1917">297</jats:related-article> </jats:p>