Catálogo de publicaciones - revistas

<jats:title>Preserving male fertility</jats:title> <jats:p> Before chemotherapy or radiation treatment, sperm from adult men can be cryopreserved for future use. However, this is not possible for prepubertal boys. Fayomi <jats:italic>et al.</jats:italic> grafted cryopreserved testicular tissue from castrated pubertal rhesus macaques, placing each animal's own testis sections under the skin of the back or scrotum (see the Perspective by Neuhaus and Schlatt). Grafts grew, produced testosterone, and were able to generate sperm that could fertilize oocytes, in one case resulting in a successful pregnancy. The results hold promise for preserving human fertility, for example, after childhood cancer treatments. </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="6433" page="1314" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aav2914">1314</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6433" page="1283" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aaw6927">1283</jats:related-article> </jats:p>

<jats:title>Locating myxomatosis resistance</jats:title> <jats:p> Myxomatosis is a viral infection that was deliberately introduced from American cottontail rabbits into European rabbit populations to control their population. Over the past 60 years or so, similar resistance variants have emerged in parallel in the United Kingdom, France, and Australia. Alves <jats:italic>et al.</jats:italic> discovered that the basis for this resistance is polygenic, with selection converging on several host immunity and proviral alleles (see the Perspective by Miller and Metcalf). Interestingly, it now seems that the virus is counterevolving immune suppressive traits. </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="6433" page="1319" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aau7285">1319</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6433" page="1277" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aaw8710">1277</jats:related-article> </jats:p>

<jats:title>Methane oxidation on the plus side</jats:title> <jats:p> Industrial conversion of methane to alcohol derivatives involves a circuitous route that starts with overoxidation to carbon monoxide. More direct approaches in highly acidic media have shown promise at small scale but are not cost-effective. Díaz-Urrutia and Ott describe a reaction at pilot-plant scale that combines methane and sulfur trioxide directly in sulfuric acid to form methanesulfonic acid with no by-products (see the Perspective by Schüth). The reaction appears to proceed via a cationic chain mechanism initiated by a low concentration of added sulfonyl peroxide and propagated by CH <jats:sub>3</jats:sub> <jats:sup>+</jats:sup> . </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="6433" page="1326" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aav0177">1326</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6433" page="1282" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aaw7738">1282</jats:related-article> </jats:p>

<jats:title>Boron brings nitrogen together</jats:title> <jats:p> Whereas carbon is prone to making chains, nitrogen usually sticks to itself just once in the particularly stable form of N <jats:sub>2</jats:sub> . Légaré <jats:italic>et al.</jats:italic> now show that boron can coax two N <jats:sub>2</jats:sub> molecules together under reductive conditions below room temperature. Two borylene units sandwiched the resulting N <jats:sub>4</jats:sub> chain between them. </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="6433" page="1329" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aav9593">1329</jats:related-article> </jats:p>

<jats:title>Solving equations with waves</jats:title> <jats:p> Signal processing of light waves can be used to represent certain mathematical functions and to perform computational tasks on signals or images in an analog fashion. Such processing typically requires complex systems of bulk optical elements such as lenses, filters, and mirrors. Mohammadi Estakhri <jats:italic>et al.</jats:italic> demonstrate that specially designed nanophotonic structures can take input waveforms encoded as complex mathematical functions, manipulate them, and provide an output that is the integral of the functions. The results, demonstrated for microwaves, provide a route to develop chip-based analog optical computers and computing elements. </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="6433" page="1333" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aaw2498">1333</jats:related-article> </jats:p>

<jats:title>A treasure trove of Cambrian secrets</jats:title> <jats:p> Animal life exploded in diversity and form during the Cambrian period about 500 million years ago. Fu <jats:italic>et al.</jats:italic> describe an early Cambrian fossil site in China that contains a variety of specimens, more than half of which are previously undescribed (see the Perspective by Daley). The site rivals previously described Cambrian sites, such as the Burgess Shale, and should help to elucidate biological innovation and diversification during this period. </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="6433" page="1338" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aau8800">1338</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6433" page="1284" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aaw8644">1284</jats:related-article> </jats:p>

<jats:title>Swarming in parallel toward sociality</jats:title> <jats:p> The evolution of social behavior, and specifically of multicellularity, is poorly understood. An experimental model for multicellularity is the myxobacteria, which swarm and cooperate to form fruiting bodies in soil. Wielgoss <jats:italic>et al.</jats:italic> studied lineages of wild-caught myxobacteria. They found diversity, but also surprising genetic similarity, within fruiting bodies that was unlikely to be based on shared ancestry between them. Instead, reoccurrence of the same mutations seems to have occurred independently. These mutations have then been selected to confer similar phenotypes that converge on social behavior. </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="6433" page="1342" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aar4416">1342</jats:related-article> </jats:p>

<jats:title>A sweetener's not-so-sweet effects</jats:title> <jats:p> Obesity increases an individual's risk of developing many types of cancer, including colorectal cancer. One of the factors driving the rise in obesity rates is thought to be the use of high-fructose corn syrup (HFCS) as a sweetener in soft drinks. Goncalves <jats:italic>et al.</jats:italic> found that ingestion of HFCS promotes the growth of intestinal cancer even in the absence of obesity in mouse tumor models. An enzyme in tumors (ketohexokinase) converts fructose to fructose-1-phosphate, which alters tumor cell metabolism and leads to enhanced cell growth. Whether a similar process occurs in humans remains to be seen. </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="6433" page="1345" related-article-type="in-this-issue" vol="363" xlink:href="10.1126/science.aat8515">1345</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>