Catálogo de publicaciones - revistas

<jats:title>A subtle balancing act for quinones</jats:title> <jats:p> Palladium catalysis is widely used in drug synthesis to form carbon-carbon bonds, but typically both carbon centers need to be activated ahead of time. Although introducing oxygen as an oxidant diminishes the need for preactivation, the catalysis then tends to be less efficient, especially in the case of arene coupling. Salazar <jats:italic>et al.</jats:italic> pinpointed the role of quinone co-catalysts in these processes and determined that after accelerating carbon-carbon bond formation, the quinone slows down catalyst reoxidation by oxygen. Appending bulky substituents to the quinone struck a better balance and substantially enhanced catalytic efficiency. </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="6523" page="1454" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd1085">1454</jats:related-article> </jats:p>

<jats:title>A light approach to quantum advantage</jats:title> <jats:p> Quantum computational advantage or supremacy is a long-anticipated milestone toward practical quantum computers. Recent work claimed to have reached this point, but subsequent work managed to speed up the classical simulation and pointed toward a sample size–dependent loophole. Quantum computational advantage, rather than being a one-shot experimental proof, will be the result of a long-term competition between quantum devices and classical simulation. Zhong <jats:italic>et al.</jats:italic> sent 50 indistinguishable single-mode squeezed states into a 100-mode ultralow-loss interferometer and sampled the output using 100 high-efficiency single-photon detectors. By obtaining up to 76-photon coincidence, yielding a state space dimension of about 10 <jats:sup>30</jats:sup> , they measured a sampling rate that is about 10 <jats:sup>14</jats:sup> -fold faster than using state-of-the-art classical simulation strategies and supercomputers. </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="6523" page="1460" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe8770">1460</jats:related-article> </jats:p>

<jats:title>Changing with the times</jats:title> <jats:p> Pandemic spread of a virus in naïe populations can select for mutations that alter pathogenesis, virulence, and/or transmissibility. The ancestral form of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged from China has now been largely replaced by strains containing the mutation D614G (Asp <jats:sup>614</jats:sup> -to-Gly) in the viral spike protein. Hou <jats:italic>et al.</jats:italic> compared the characteristics of the new variant against the ancestral form in a series of experiments in human cells and animal models. The variant is better at infecting upper-airway epithelial cells and replicates in greater numbers than the ancestral virus. Evidence indicates modest, if any, significant changes to virulence in animal models. Therefore, the virus appears to have evolved for greater transmissibility in humans rather than for greater pathogenicity. The mutation renders the new virus variant more susceptible to neutralizing antisera without altering the efficacy of vaccine candidates currently under 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="6523" page="1464" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe8499">1464</jats:related-article> </jats:p>

<jats:title>Mountain ecology under climate change</jats:title> <jats:p> Climate warming causes shifts in the distributions of organisms and different organisms may move at different rates, resulting in changes in the composition and functioning of ecological communities. These effects are rarely considered in forecasts about the effects of climate change on biodiversity. Using experimental translocations, Descombes <jats:italic>et al.</jats:italic> investigated how differential upslope migration in alpine plants and their insect herbivores affects community interactions. Lowland herbivores modify the three-dimensional vegetation structure at higher altitudes, and this modified vegetation structure favors the coexistence of plant species, especially by favoring small-stature species. Reorganized trophic interactions will play an important role in driving plant community changes under future climate change. </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="6523" page="1469" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abd7015">1469</jats:related-article> </jats:p>

<jats:title>Nanobodies that neutralize</jats:title> <jats:p> Monoclonal antibodies that bind to the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) show therapeutic promise but must be produced in mammalian cells and need to be delivered intravenously. By contrast, single-domain antibodies called nanobodies can be produced in bacteria or yeast, and their stability may enable aerosol delivery. Two papers now report nanobodies that bind tightly to spike and efficiently neutralize SARS-CoV-2 in cells. Schoof <jats:italic>et al.</jats:italic> screened a yeast surface display of synthetic nanobodies and Xiang <jats:italic>et al.</jats:italic> screened anti-spike nanobodies produced by a llama. Both groups identified highly potent nanobodies that lock the spike protein in an inactive conformation. Multivalent constructs of selected nanobodies achieved even more potent neutralization. </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="6523" page="1473" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe3255">1473</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6523" page="1479" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe4747">1479</jats:related-article> </jats:p>

<jats:title>Nanobodies that neutralize</jats:title> <jats:p> Monoclonal antibodies that bind to the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) show therapeutic promise but must be produced in mammalian cells and need to be delivered intravenously. By contrast, single-domain antibodies called nanobodies can be produced in bacteria or yeast, and their stability may enable aerosol delivery. Two papers now report nanobodies that bind tightly to spike and efficiently neutralize SARS-CoV-2 in cells. Schoof <jats:italic>et al.</jats:italic> screened a yeast surface display of synthetic nanobodies and Xiang <jats:italic>et al.</jats:italic> screened anti-spike nanobodies produced by a llama. Both groups identified highly potent nanobodies that lock the spike protein in an inactive conformation. Multivalent constructs of selected nanobodies achieved even more potent neutralization. </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="6523" page="1473" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe3255">1473</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6523" page="1479" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe4747">1479</jats:related-article> </jats:p>