Catálogo de publicaciones - revistas

<jats:title>Sinking into the bulk of a Weyl semimetal</jats:title> <jats:p> A recently discovered class of topological materials, Weyl semimetals, have surface states in the form of so-called Fermi arcs. Inoue <jats:italic>et al.</jats:italic> used a high-resolution scanning tunneling microscope to explore the properties of these states in the material TaAs. They mapped the scattering of electrons off impurities on the surface of the material and compared the data to the predictions of density functional theory. The data could be reconciled with the theory only if electrons associated with Ta orbitals on the Fermi arcs sank into the bulk of the 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="6278" page="1184" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad8766">1184</jats:related-article> </jats:p>

<jats:title>Radically faster synthesis</jats:title> <jats:p> Zeolite synthesis normally proceeds under basic conditions that allow the oxide bridges between aluminum and silicon atoms to break and reform. Feng <jats:italic>et al.</jats:italic> show that the formation of hydroxyl radicals, either by irradiation with ultraviolet light or with the Fenton reagent, can speed up the formation of the crystallized zeolite by about a factor of 2. </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="6278" page="1188" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aaf1559">1188</jats:related-article> </jats:p>

<jats:title>Mining gut fungi to break down biomass</jats:title> <jats:p> The recalcitrance of plant biomass remains a formidable bottleneck in the production of biofuels and other chemicals from renewable sources. Enzymes from microbial communities found within ruminants and hindgut fermenters, however, show considerable promise to break down plant material into simple sugars efficiently. Solomon <jats:italic>et al.</jats:italic> used 'omics-level and biochemical assays to reveal a suite of lignocellulose-degrading enzymes from early-diverging anaerobic fungi isolated from the guts of horses, goats, and sheep. This approach not only reveals the regulation of these pathways but also represents a method to identify enzymes with no known homologs that would be unidentifiable using conventional screening methods. </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="6278" page="1192" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad1431">1192</jats:related-article> </jats:p>

<jats:title>Some bacteria think plastic is fantastic</jats:title> <jats:p> Bacteria isolated from outside a bottle-recycling facility can break down and metabolize plastic. The proliferation of plastics in consumer products, from bottles to clothing, has resulted in the release of countless tons of plastics into the environment. Yoshida <jats:italic>et al.</jats:italic> show how the biodegradation of plastics by specialized bacteria could be a viable bioremediation strategy (see the Perspective by Bornscheuer). The new species, <jats:italic>Ideonella sakaiensis</jats:italic> , breaks down the plastic by using two enzymes to hydrolyze PET and a primary reaction intermediate, eventually yielding basic building blocks for growth. </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="6278" page="1196" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad6359">1196</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6278" page="1154" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aaf2853">1154</jats:related-article> </jats:p>

<jats:title>Signal problems in autism spectrum disorder</jats:title> <jats:p> Autism spectrum disorders have many causes. Bidinosti <jats:italic>et al.</jats:italic> studied Phelan-McDermid syndrome (PMDS), one of the symptoms of which can be autism (see the Perspective by Burbach). The authors used neurons derived from these patients, as well as from mice, with the culprit gene disrupted and found that a chain of intracellular signals becomes imbalanced. Signaling and behavioral symptoms could be improved by a small-molecule therapeutic that inhibits a key kinase. </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="6278" page="1199" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad5487">1199</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6278" page="1153" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aaf5097">1153</jats:related-article> </jats:p>

<jats:title>Timing the attack on cancer cells</jats:title> <jats:p> Cell regulatory systems have dynamic properties that will need to be taken into account when planning therapeutic strategies. Chen <jats:italic>et al.</jats:italic> found that the timing of a radiation treatment of human breast cancer–derived cells in culture determined whether cell survival was enhanced or reduced. Depletion of the oncogene product MDMX caused an initial burst of expression of the tumor suppressor protein p53 within the first 24 hours, and then oscillations of lower amplitude. When the radiation treatment coincided with the first phase, 95% of the cells died, but if radiation was applied in the second phase, fewer than 20% of the cells died. </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="6278" page="1204" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aac5610">1204</jats:related-article> </jats:p>

<jats:title>Tumors put in a vulnerable position</jats:title> <jats:p> Cancer cells often display alterations in metabolism that help fuel their growth. Such metabolic “rewiring” may also work against the cancer cells, however, by creating new vulnerabilities that can be exploited therapeutically. A variety of human tumors show changes in methionine metabolism caused by loss of the gene coding for 5-methylthioadenosine phosphorylase (MTAP). Mavrakis <jats:italic>et al.</jats:italic> and Kryukov <jats:italic>et al.</jats:italic> found that the loss of MTAP renders cancer cell lines sensitive to growth inhibition by compounds that suppress the activity of a specific arginine methyltransferase called PRMT5. Conceivably, drugs that inhibit PRMT5 activity could be developed into a tailored therapy for MTAP-deficient tumors. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue pp. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6278" page="1208" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad5944">1208</jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6278" page="1214" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad5214">1214</jats:related-article> </jats:p>

<jats:title>Tumors put in a vulnerable position</jats:title> <jats:p> Cancer cells often display alterations in metabolism that help fuel their growth. Such metabolic “rewiring” may also work against the cancer cells, however, by creating new vulnerabilities that can be exploited therapeutically. A variety of human tumors show changes in methionine metabolism caused by loss of the gene coding for 5-methylthioadenosine phosphorylase (MTAP). Mavrakis <jats:italic>et al.</jats:italic> and Kryukov <jats:italic>et al.</jats:italic> found that the loss of MTAP renders cancer cell lines sensitive to growth inhibition by compounds that suppress the activity of a specific arginine methyltransferase called PRMT5. Conceivably, drugs that inhibit PRMT5 activity could be developed into a tailored therapy for MTAP-deficient tumors. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue pp. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6278" page="1208" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad5944">1208</jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6278" page="1214" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad5214">1214</jats:related-article> </jats:p>

<jats:title>Stochastic properties of phage promoter</jats:title> <jats:p> Full understanding of regulated gene expression requires characterization of stochastic variation in the activity of individual promoters. To avoid cell-to-cell variability and variation between the activity of specific gene copies, Sepúlveda <jats:italic>et al.</jats:italic> investigated the behavior of the lysogeny maintenance promoter of phage lambda in individual <jats:italic>Escherichia coli</jats:italic> cells. They measured the concentration of transcription factor and the actual number of mRNAs produced, and used mathematical modeling to discern the stochastic activity of the regulated promoter. The promoter underwent switching between configurations that occurred more rapidly than the lifetime of mRNA molecules produced, and individual copies of the same gene functioned independently in the same cell. Such studies can reveal new aspects of systems that have been well studied by more conventional techniques. </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="6278" page="1218" related-article-type="in-this-issue" vol="351" xlink:href="10.1126/science.aad0635">1218</jats:related-article> </jats:p>

<jats:p>Celebrating its 120th anniversary in 2016, Shanghai Jiao Tong University (SJTU) remains one of the most prestigious—and oldest—universities in China. During its long history, SJTU has built a tradition of excellence in research and development, particularly in science, engineering, and medicine. This supplement showcases some of the research currently underway at the university, highlighting advances in engineering, physics, bioagriculture, and biomedicine, among others.</jats:p> <jats:p> This special supplement brought to you by the <jats:bold>Science</jats:bold> /AAAS Custom Publishing Office. </jats:p>