Catálogo de publicaciones - revistas

<jats:title>Liquid crystals on a deformable substrate</jats:title> <jats:p> The orientation of the molecules in a liquid crystalline material will change in response to either changes in the substrate or an external field. This is the basis for liquid crystalline devices. Vesicles, which are fluid pockets surrounded by lipid bilayers, will change size or shape in response to solvent conditions or pressure. Keber <jats:italic>et al.</jats:italic> report on the rich interactions between nematic liquid crystals placed on the surface of a vesicle. Changes to the vesicle size, for example, can “tune” the liquid crystal molecules. But conversely, the shape of the vesicles can also change in response to the activity of the nematic molecules. </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="6201" page="1135" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254784">1135</jats:related-article> </jats:p>

<jats:title>Dipeptide repeat peptides on the attack</jats:title> <jats:p> Certain neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), are associated with expanded dipeptides translated from RNA transcripts of disease-associated genes (see the Perspective by West and Gitler). Kwon <jats:italic>et al.</jats:italic> show that the peptides encoded by the expanded repeats in the C9orf72 gene interfere with the way cells make RNA and kill cells. These effects may account for how this genetic form of ALS causes disease. Working in <jats:italic>Drosophila</jats:italic> , Mizielinska <jats:italic>et al.</jats:italic> aimed to distinguish between the effects of repeat-containing RNAs and the dipeptide repeat peptides that they encode. The findings provide evidence that dipeptide repeat proteins can cause toxicity directly. </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="6201" page="1139" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254917">1139</jats:related-article> and p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6201" page="1192" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1256800">1192</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6201" page="1118" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1259461">1118</jats:related-article> </jats:p>

<jats:title>Optically manipulating superconductors</jats:title> <jats:p> In superconductors, electrons of opposite momenta pair to form a highly correlated state that manages to flow without encountering any resistance. Matsunaga <jats:italic>et al.</jats:italic> manipulated the wavefunction of these pairs in the superconductor NbN with an electromagnetic pulse that they transmitted through a thin layer of the material (see the Perspective by Pashkin and Leitenstorfer). The superconducting gap, which is the energy needed to break the pairs apart, oscillated at twice the frequency of the pulse's electric field. When they matched this frequency to half the gap, the authors excited a collective mode in the superconductor called the Higgs mode, a relative of the Higgs boson in particle physics. </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="6201" page="1145" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254697">1145</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6201" page="1121" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1257302">1121</jats:related-article> </jats:p>

<jats:title>Tuning the twisting in helical nanowires</jats:title> <jats:p> Assembly of inorganic nanoparticles into complex structures often requires a template. Researchers can now assemble helical nanowires out of cubic magnetite nanocrystals by tuning interactions that bind or separate them. Singh <jats:italic>et al.</jats:italic> floated the nanocrystals on a liquid and aligned them with a magnetic field. After the liquid evaporated, different twisted nanowires remained. The helices varied according to the concentration of nanocrystals, their shape, and the strength of the magnetic field. Competition between weak forces drives this self-assembly and can lead to arrays with the same twist direction. </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="6201" page="1149" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254132">1149</jats:related-article> </jats:p>

<jats:title>A metal alloy that is stronger when cold</jats:title> <jats:p> Metal alloys normally consist of one dominant element, with others in small amounts to improve specific properties. For example, stainless steel is primarily iron with nickel and chromium but may contain trace amounts of other elements. Gludovatz <jats:italic>et al.</jats:italic> explored the properties of a high-entropy alloy made from equal amounts of chromium, manganese, iron, cobalt, and nickel. Not only does this alloy show excellent strength, ductility, and toughness, but these properties improve at cryogenic temperatures where most alloys change from ductile to brittle. </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="6201" page="1153" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254581">1153</jats:related-article> </jats:p>