Catálogo de publicaciones - revistas

<jats:title>How big is the proton?</jats:title> <jats:p> The discrepancy between the size of the proton extracted from the spectroscopy of muonic hydrogen and the value obtained by averaging previous results for “regular” hydrogen has puzzled physicists for the past 7 years. Now, Beyer <jats:italic>et al.</jats:italic> shed light on this puzzle (see the Perspective by Vassen). The authors obtained the size of the proton using very accurate spectroscopic measurements of regular hydrogen. Unexpectedly, this value was inconsistent with the average value of previous measurements of the same type. Also unexpectedly, it was consistent with the size extracted from the muonic hydrogen experiments. Resolving the puzzle must now include trying to understand how the old results relate to the new, as well as reexamining the sources of systematic errors in all experiments. </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="6359" page="79" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aah6677">79</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6359" page="39" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aao3969">39</jats:related-article> </jats:p>

<jats:title>A triple threat for HIV</jats:title> <jats:p> The HIV virus continually evolves tricks to evade elimination by the host. Prevention and a cure will likely rely on broadly neutralizing antibodies that can recognize and conquer multiple viral strains or subtypes. Xu <jats:italic>et al.</jats:italic> engineered a single antibody molecule to recognize three highly conserved proteins needed for HIV infection (see the Perspective by Cohen and Corey). This “trispecific” antibody uses two sites (V1V2 and MPER) to bind HIV-infected cells, while the third site (CD4bs) recruits killer T lymphocytes that can eliminate the virus. When tested against &gt;200 different HIV strains, trispecific antibodies were highly potent and broadly neutralized ∼99% of HIV viruses. This approach could potentially simplify HIV treatment regimens and improve therapy response. </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="6359" page="85" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aan8630">85</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6359" page="46" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aap8131">46</jats:related-article> </jats:p>

<jats:title>Making a denser optical lattice clock</jats:title> <jats:p> Some of today's most advanced clocks are made up of large numbers of atoms lined up in a one-dimensional (1D) optical lattice. The numbers improve clock stability, but atomic interactions can limit accuracy. Campbell <jats:italic>et al.</jats:italic> loaded their fermionic strontium atoms into a 3D optical lattice. The low temperatures and strong interactions ensured that the atoms avoided one another, resulting in a neat pattern where each lattice site was occupied by exactly one atom. This ordering reduced the influence of interactions on the clock's accuracy, whereas the high density of atoms enabled by the 3D geometry improved the precision. </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="6359" page="90" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aam5538">90</jats:related-article> </jats:p>

<jats:title>Harnessing complexity in laser light</jats:title> <jats:p> The development of lasers and the quality of the output light has been crucially dependent on understanding and being able to control the process occurring within the laser-generating cavity. In a real laser cavity, there are both longitudinal and transverse modes; for the highest-quality lasers, reducing the effects of the latter has been standard practice. However, using a graded index fiber cavity, Wright <jats:italic>et al.</jats:italic> demonstrate that the longitudinal and transverse modes can be locked to provide an output of complex coherent light. Harnessing, rather than filtering out, the transverse modes could produce a valuable and flexible light source applicable across a broad range of disciplines. </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="6359" page="94" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aao0831">94</jats:related-article> </jats:p>

<jats:title>Giving grain boundaries more structure</jats:title><jats:p>The properties of metals change depending on the composition and structure of grain boundaries in polycrystalline materials. Yu<jats:italic>et al.</jats:italic>discovered a surprising grain boundary superstructure in a nickel-bismuth alloy. Previously, the structure was only known to exist in a specific type of uncommon grain boundary, and experiments had focused on bicrystals. Unexpectedly, this alloy has grain boundary superstructures across a wide range of boundaries in polycrystalline samples. This likely also occurs in other alloys, which opens an avenue for grain boundary engineering to tune the physical properties of metals and ceramics.</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="6359" page="97" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aam8256">97</jats:related-article></jats:p>

<jats:title>Climate and the carbon cycle</jats:title> <jats:p> It is still not clear how global warming will affect the global carbon cycle, either in terms of the magnitude of the effect or even its sign. Help in answering that question will come from long-term field-based experiments designed to explore carbon cycle-climate feedbacks in an ecosystem context. Melillo <jats:italic>et al.</jats:italic> performed a 26-year soil-warming experiment in a mid-latitude hardwood forest (see the Perspective by Metcalfe). Warming has resulted in a complex pattern of net carbon loss from the soil. These results support projections of a long-term, positive carbon feedback from similar ecosystems as the world warms. </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="6359" page="101" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aan2874">101</jats:related-article> ; See also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6359" page="41" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aap7325">41</jats:related-article> </jats:p>

<jats:title>Price modulates early pain processing</jats:title> <jats:p> Patients in randomized clinical trials frequently stop taking their drug, complaining of side effects. However, it turns out that some of these subjects are part of the placebo group and thus never received any active medication. This is a case of the nocebo effect seriously interfering with medical treatment. Tinnermann <jats:italic>et al.</jats:italic> investigated whether value information such as the price of a medication can further modulate behavioral nocebo effects and the underlying neural network dynamics (see the Perspective by Colloca). They used brain imaging to characterize the circuits involved in nocebo hyperalgesia within the descending pain pathway from the prefrontal cortex to the spinal cord. Their findings revealed how value information increased the nocebo effect. </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="6359" page="105" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aan1221">105</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6359" page="44" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aap8488">44</jats:related-article> </jats:p>