Catálogo de publicaciones - revistas

<jats:title>Confining peroxide to make methanol</jats:title> <jats:p> In principle, hydrogen peroxide would be an efficient oxidant for the conversion of methane to methanol under mild conditions. In practice, however, it is currently too expensive to produce the peroxide ahead of time for this purpose. Jin <jats:italic>et al.</jats:italic> report a catalyst system that generates and concentrates hydrogen peroxide for immediate reaction with methane. A hydrophobically coated zeolite keeps the peroxide close to the gold and palladium active site, where incoming methane is then selectively oxidized to methanol. </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="6474" page="193" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaw1108">193</jats:related-article> </jats:p>

<jats:title>Apoptosis prevents left-right crossing</jats:title> <jats:p>Animals generally display a bilateral body plan, with symmetry between the left and right sides. Maya-Ramos and Mikawa examined the mechanism that prevents the crossing of cells between sides. Using chick embryos, they show that cellular mixing between sides is prevented by a barrier at the embryonic midline that involves programmed cell death and the extracellular matrix. This work demonstrates the dependence of normal development on programmed cell death during the gastrulation stage.</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="6474" page="197" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaw2731">197</jats:related-article> </jats:p>

<jats:title>Challenges of drug combinations</jats:title> <jats:p> Combinations of antibiotics are used to treat intractable infections such as methicillin-resistant <jats:italic>Staphylococcus aureus</jats:italic> . Clinically, however, drugs tend to be used empirically, and results can be contradictory. Liu <jats:italic>et al.</jats:italic> translated observations made in vitro to patient samples to understand the role of antibiotic tolerance in promoting or suppressing resistance when drug combinations are used (see the Perspective by Berti and Hirsch). Although bacterial populations exposed to multiple antibiotics can develop tolerance to multiple drugs, one drug in a combination may be able counter resistance to a partner drug and provide effective therapy. However, if tolerance has already emerged to one drug, the combination may end up promoting the transmission of resistance to a partner drug. </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="6474" page="200" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay3041">200</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6474" page="141" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba0150">141</jats:related-article> </jats:p>

<jats:title>A tRNA synthase in metabolic control</jats:title> <jats:p> Leucyl-tRNA synthetase 1 (LARS1), which covalently couples leucine to its cognate transfer RNAs (tRNAs), appears to have broader roles in the control of leucine metabolism. The enzyme also serves as a leucine sensor for the mechanistic target of rapamycin complex 1 (mTORC1), which regulates protein synthesis, metabolism, autophagy, and cell growth. Yoon <jats:italic>et al.</jats:italic> show that in cells deprived of glucose, LARS1 is phosphorylated by Unc-51 like autophagy activating kinase 1 (see the Perspective by Lehman and Abraham). This phosphorylation decreases leucine binding to LARS1 and, in turn, should decrease translation, reduce activation of mTORC1, and perhaps free up leucine for use in the generation of adenosine triphosphate in glucose-starved cells. </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="6474" page="205" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aau2753">205</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6474" page="146" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba2335">146</jats:related-article> </jats:p>

<jats:title>Dating the arrival of the first hominins in Java</jats:title> <jats:p> The World Heritage archaeological site at Sangiran on the island of Java in Indonesia has major importance for the understanding of human arrival and evolution in Asia. However, the timing of the first appearance of <jats:italic>Homo erectus</jats:italic> at the site has been controversial. Using a combination of dating techniques for hominin-bearing sediments, Matsu'ura <jats:italic>et al.</jats:italic> resolved the arrival of <jats:italic>H. erectus</jats:italic> at ∼1.3 million years ago (see the Perspective by Brasseur). This dating suggests that the earliest hominins in Sangiran are at least 200,000 years younger than has been thought and may represent an important step to the resolution of the controversy. </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="6474" page="210" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aau8556">210</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6474" page="147" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba3800">147</jats:related-article> </jats:p>

<jats:p>3D bioprinting allows researchers to construct increasingly elaborate living structures. A new generation of accessible tools has opened the field to many more labs.</jats:p>

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