Catálogo de publicaciones - revistas

<jats:p> The structure and dynamics of a two-dimensional silica film provide fundamental insights into amorphous materials. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="224" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242248"> Huang <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p>A data center design based on an integrated chip-scale approach will be required to deal with the increasing volumes of Internet traffic.</jats:p>

<jats:p> Mechanical forces exerted between tissue layers in the intestine are all that is needed to make gut villi. <jats:named-content content-type="related-content"> [Also see Research Article by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="212" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1238842"> Shyer <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> Efforts to reduce the phosphorus input to lakes have helped to lessen algal blooms but exacerbated nitrate pollution. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="247" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242575"> Finlay <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> Genetic and epigenetic studies of gene variants reveal a potential genomic target for treating hemoglobin disorders. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="253" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242088"> Bauer <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> No longer elusive, mammalian antiviral RNA interference is now confirmed. <jats:named-content content-type="related-content"> [Also see Reports by <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/content/342/6155/231.full"> Li <jats:italic>et al.</jats:italic> </jats:ext-link> and <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/content/342/6155/235.full"> Maillard <jats:italic>et al.</jats:italic> </jats:ext-link> ] </jats:named-content> </jats:p>

<jats:title>Intestinal Villus Formation</jats:title> <jats:p> The intestinal villi are essential elaborations of the lining of the gut that increase the epithelial surface area for nutrient absorption. <jats:bold> Shyer <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="212" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1238842">212</jats:related-article> , published online 29 August; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="203" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1245288">Simons</jats:related-article> </jats:bold> ) show that in both the developing human and chick gut, the villi are formed in a step-wise progression, involving the sequential folding of the endoderm into longitudinal ridges, via a zigzag pattern, to finally form individual villi. These changes are established through the differentiation of the smooth muscle layers of the gut, restricting the expansion of the adjacent proliferating and growing endoderm and mesenchyme, generating compressive stresses that lead to the buckling and folding of the tissue. </jats:p>

<jats:title>Remnants of a Water-Bearing World</jats:title> <jats:p> Stars like the Sun end their lives as white dwarfs. <jats:bold> Farihi <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="218" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1239447">218</jats:related-article> ) used detailed spectroscopic analysis of a debris-accreting white dwarf, along with knowledge that such systems accrete this debris from remnants of rocky planetary bodies, to derive the water content in a disrupted extrasolar body. The findings suggest that the white dwarf contains the signature of a rocky minor planet composed of 26% water by mass. </jats:p>

<jats:title>Elastic to Plastic</jats:title> <jats:p> When a crystal is mechanically compressed, it first reacts elastically (reversibly), and then enters the plastic regime, in which the structure of the material is irreversibly changed. This process can be studied with molecular dynamics (MD) simulations on very fine temporal and spatial scales, but experimental analysis has lagged behind. <jats:bold> Milathianaki <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="220" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1239566">220</jats:related-article> ) shocked polycrystalline copper with a laser beam, and then took successive snapshots of the crystal structure at 10-picosecond intervals. The results were compared directly with atomistic simulations and revealed that the yield stress—the point of transition from plastic to elastic response—agreed well with MD predictions. </jats:p>

<jats:title>Glassy Eyed</jats:title> <jats:p> In crystalline materials, the collective motion of atoms in one- and two-dimensional defects—like dislocations and stacking faults—controls the response to an applied strain, but how glassy materials change their structure in response to strain is much less clear. <jats:bold> Huang <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="224" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242248">224</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6155" page="201" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1245217">Heyde</jats:related-article> </jats:bold> ) used advanced-transmission electron microscopy to investigate the structural rearrangements in a two-dimensional glass, including the basis for shear deformations and the atomic behavior at the glass/liquid interface. </jats:p>