Nature Materials contents: March 2013 Volume 12 Number 3 pp173-275

Advertisement Simplify Polymer Analysis with Non-destructive analysis of any sample size and shape Whether you develop and manufacture new polymers, fabricate polymer components, or use polymers in your own products, Agilent has the perfect tools for you. View webinar, videos and application compendium and learn more about our comprehensive portfolio of polymer solutions. TABLE OF CONTENTS March 2013 Volume 12, Issue 3 Editorial Commentary Research Highlights News and Views Review Letters Articles Subscribe   Facebook   RSS   Recommend to library   Twitter   Advertisement Attending the APS Meeting in Baltimore? Visit Nature Physics at the Nature Publishing Group booth #431 to: - Take part in our prize draw - Browse and take free sample copies of leading journals from NPG, including Nature and Nature Physics - Save up to 30% on personal subscriptions   Editorial Top Fuelling discovery by sharing   p173 doi:10.1038/nmat3594 The United States Materials Genome Initiative aims at accelerating the discovery, development and deployment of materials. Yet, finding data standards and sharing practices that can be leveraged by the disparate communities in materials science and technology may prove difficult. Commentary Top Unidirectional light propagation at exceptional points   pp175 - 177 Xiaobo Yin and Xiang Zhang doi:10.1038/nmat3576 Unique opportunities arise from exceptional points that coalesce states of an open system in synthetic photonic media, where delicately balanced complex dielectric functions produce unprecedented optical properties. Research Highlights Top Squeeze to deliver | A moment of change | High-performance nanotubes | The virus catcher | Optical nanocircuits News and Views Top Patchy colloids: Entropy stabilizes open crystals   pp179 - 180 Michael E. Cates doi:10.1038/nmat3573 Open crystalline configurations self-assembled from colloids with sticky patches have recently been shown to be unexpectedly stable. A theory that accounts for the entropy of the colloids' thermal fluctuations now explains why. See also: Letter by Mao et al. Bioengineering and regenerative medicine: Keeping track   pp180 - 181 Keren Ziv and Sanjiv S. Gambhir doi:10.1038/nmat3579 Assessing when cell death occurs following in vivo transplantation of stem cells is challenging. Now, pH-sensitive hydrogel capsules containing arginine-based liposomes are shown to act as magnetic resonance imaging contrast agents, allowing cell death to be monitored within the capsules. See also: Article by Chan et al. Negative linear compressibility: Giant response   pp182 - 183 Ruben Gatt, Roberto Caruana-Gauci and Joseph N. Grima doi:10.1038/nmat3584 Materials displaying negative linear compressibility are, at present, the exception rather than the rule. An unusually large and persistent example of this phenomenon in the molecular framework material zinc dicyanoaurate dramatically expands the range of mechanical responses conceivable in other materials. See also: Letter by Cairns et al. Material witness: Living crystals   p183 Philip Ball doi:10.1038/nmat3582 Cell rheology: Mush rather than machine   pp184 - 185 Enhua H. Zhou, Fernando D. Martinez and Jeffrey J. Fredberg doi:10.1038/nmat3574 The cytoplasm of living cells responds to deformation in much the same way as a water-filled sponge does. This behaviour, although intuitive, is connected to long-standing and unsolved fundamental questions in cell mechanics. See also: Article by Moeendarbary et al. Spider silk: Webs measure up   pp185 - 187 Zhao Qin and Markus J. Buehler doi:10.1038/nmat3578 The complete elastic response of a spider's orb web has been quantified by non-invasive light scattering, revealing important insights into the architecture, natural material use and mechanical properties of the web. This knowledge advances our understanding of the prey-catching process and the role of supercontraction therein. See also: Article by Koski et al. Liquid crystals: Interplay of topologies   pp187 - 189 Eugene Terentjev doi:10.1038/nmat3583 In a uniformly aligned liquid crystal, colloidal particles having a number of holes give rise to arrays of topological defects that are associated with the particles' topology. Nature Materials JOBS of the week PhD Student Position in Applied Physics Chalmers University of Technology Research Chair McGill University Kinetics of Martensite Phase Transitions Max Plank Institute for Intelligent Systems Postdoctoral position in superconducting THz electronics Chalmers University of Technology More Science jobs from Nature Materials EVENT International conference on photorefractive effects, materials and devices 09.07.13 Winchester, UK More science events from Review Top The high-throughput highway to computational materials design   pp191 - 201 Stefano Curtarolo, Gus L. W. Hart, Marco Buongiorno Nardelli, Natalio Mingo, Stefano Sanvito and Ohad Levy doi:10.1038/nmat3568 High-throughput computational approaches combining thermodynamic and electronic-structure methods with data mining and database construction are increasingly used to analyse huge amounts of data for the discovery and design of new materials. This Review provides an overall perspective of the field for a broad range of materials, and discusses upcoming challenges and opportunities. Letters Top Dynamic control of magnetic nanowires by light-induced domain-wall kickoffs   pp202 - 206 Eric Heintze, Fadi El Hallak, Conrad Clauß, Angelo Rettori, Maria Gloria Pini, Federico Totti, Martin Dressel and Lapo Bogani doi:10.1038/nmat3498 The dynamical properties of single-chain magnets are difficult to control experimentally. The demonstration of a scheme for switching individual spins optically now allows for the study and manipulation of dynamical processes in magnetic nanowires with comparative ease. Tightly bound trions in monolayer MoS2    pp207 - 211 Kin Fai Mak, Keliang He, Changgu Lee, Gwan Hyoung Lee, James Hone, Tony F. Heinz and Jie Shan doi:10.1038/nmat3505 The appealing electronic properties of the monolayer semiconductor molybdenum disulphide make it a candidate material for electronic devices. The observation of tightly bound trions in this system—which have no analogue in conventional semiconductors—opens up possibilities for controlling these quasiparticles in future optoelectronic applications. Giant negative linear compressibility in zinc dicyanoaurate   pp212 - 216 Andrew B. Cairns, Jadna Catafesta, Claire Levelut, Jérôme Rouquette, Arie van der Lee, Lars Peters, Amber L. Thompson, Vladimir Dmitriev, Julien Haines and Andrew L. Goodwin doi:10.1038/nmat3551 The expansion of a material in one or more directions under increasing hydrostatic pressure is a phenomenon known as negative linear compressibility. The demonstration that zinc dicyanoaurate exhibits an unusually large negative linear compressibility opens up possibilities for designing other materials with comparable properties. See also: News and Views by Gatt et al. Entropy favours open colloidal lattices   pp217 - 222 Xiaoming Mao, Qian Chen and Steve Granick doi:10.1038/nmat3496 The design of open crystalline arrangements of colloidal particles with attractive patches has been hampered by the difficulty in exploring the full range of conceivable parameters both experimentally or with simulations. An analytical theory that explains the role of entropy in stabilizing open colloidal lattices and that predicts the conditions at which stable crystal structures of patchy particles form is now reported. See also: News and Views by Cates Imaging the dynamics of individually adsorbed molecules   pp223 - 227 Johannes Schaffert, Maren C. Cottin, Andreas Sonntag, Hatice Karacuban, Christian A. Bobisch, Nicolás Lorente, Jean-Pierre Gauyacq and Rolf Möller doi:10.1038/nmat3527 Because it is an intrinsically slow technique, scanning tunnelling microscopy is not usually useful for studying the dynamics of particles on a surface. This issue is now solved by using scanning noise microscopy, which yields a complete characterization of copper phthalocyanine molecules on Cu(111), ranging from the dynamical processes to the underlying electronic structure at the single-molecule level. A rechargeable room-temperature sodium superoxide (NaO2) battery   pp228 - 232 Pascal Hartmann, Conrad L. Bender, Miloš Vračar, Anna Katharina Dürr, Arnd Garsuch, Jürgen Janek and Philipp Adelhelm doi:10.1038/nmat3486 Rechargeable metal–air batteries are considered particularly attractive due to their potential high-energy densities and simplicity of the underlying cell reaction. A room-temperature sodium–oxygen cell with an ether-based electrolyte demonstrates enhanced current densities using pure carbon cathodes without an added catalyst. Articles Top Photonic topological insulators   pp233 - 239 Alexander B. Khanikaev, S. Hossein Mousavi, Wang-Kong Tse, Mehdi Kargarian, Allan H. MacDonald and Gennady Shvets doi:10.1038/nmat3520 Non-trivial topological phases can allow for one-way spin-polarized transport along the interfaces of topological insulators but they are relatively uncommon in the condensed state of matter. By arranging judiciously designed metamaterials into two-dimensional superlattices, a photonic topological insulator has now been demonstrated theoretically, enabling unidirectional spin-polarized photon propagation without the application of external magnetic fields or breaking of time-reversal symmetry. Layer thickness dependence of the current-induced effective field vector in Ta|CoFeB|MgO    pp240 - 245 Junyeon Kim, Jaivardhan Sinha, Masamitsu Hayashi, Michihiko Yamanouchi, Shunsuke Fukami, Tetsuhiro Suzuki, Seiji Mitani and Hideo Ohno doi:10.1038/nmat3522 The control and manipulation of the magnetization of thin metallic films by means of an electric current is a promising strategy for ensuring that potential spintronic applications are energy efficient. It is now shown that large changes in the current-induced magnetic field can arise as a result of varying the thickness of the Ta layer in Ta|CoFeB|MgO heterostructures. Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters   pp246 - 252 Woo Jong Yu, Zheng Li, Hailong Zhou, Yu Chen, Yang Wang, Yu Huang and Xiangfeng Duan doi:10.1038/nmat3518 Graphene has attracted considerable interest for future electronics, but the absence of a bandgap limits its direct applicability in transistors and logic devices. It is now shown that vertical integration with MoS2 and other layered materials enables the fabrication of vertical field-effect transistors with large on/off ratios and high current densities as well as complementary inverters with larger-than-unity voltage gain. The cytoplasm of living cells behaves as a poroelastic material   pp253 - 261 Emad Moeendarbary, Léo Valon, Marco Fritzsche, Andrew R. Harris, Dale A. Moulding, Adrian J. Thrasher, Eleanor Stride, L. Mahadevan and Guillaume T. Charras doi:10.1038/nmat3517 It has been suggested that the cytoplasm of living cells can be described as a porous elastic meshwork bathed in an interstitial fluid. Microindentation tests now show that intracellular water redistribution plays a fundamental role in cellular rheology and that at physiologically relevant timescales cellular responses to mechanical stresses are consistent with such a poroelastic model. See also: News and Views by Zhou et al. Non-invasive determination of the complete elastic moduli of spider silks   pp262 - 267 Kristie J. Koski, Paul Akhenblit, Keri McKiernan and Jeffery L. Yarger doi:10.1038/nmat3549 The mechanical properties of a spider’s web are spatially mapped using Brillouin light scattering. This non-contact approach can probe the elastic properties of single fibres, intersection points and glue spots within the web, as well as measure how the elastic stiffness changes in supercontracted silk fibres. See also: News and Views by Qin & Buehler MRI-detectable pH nanosensors incorporated into hydrogels for in vivo sensing of transplanted-cell viability   pp268 - 275 Kannie W. Y. Chan, Guanshu Liu, Xiaolei Song, Heechul Kim, Tao Yu, Dian R. Arifin, Assaf A. Gilad, Justin Hanes, Piotr Walczak, Peter C. M. van Zijl, Jeff W. M. Bulte and Michael T. McMahon doi:10.1038/nmat3525 The monitoring of cell survival and functionality following their in vivo transplantation remains a challenge in clinical cell therapy. Now, using magnetic resonance imaging techniques and microcapsules with pH-sensitive components, in vivo cell death and cell viability patterns can be assessed with high anatomical accuracy. See also: News and Views by Ziv & Gambhir Top Advertisement Want access to the best research in materials science and technology? Nature Materials provides cutting-edge research across the entire spectrum of materials science and technology. Recommend Nature Materials to your library using our library recommendation form.   Natureevents is a fully searchable, multi-disciplinary database designed to maximise exposure for events organisers. The contents of the Natureevents Directory are now live. The digital version is available here. Find the latest scientific conferences, courses, meetings and symposia on natureevents.com. For event advertising opportunities across the Nature Publishing Group portfolio please contact natureevents@nature.com More Nature Events

You have been sent this Table of Contents Alert because you have opted in to receive it. You can change or discontinue your e-mail alerts at any time, by modifying your preferences on your nature.com account at: www.nature.com/myaccount (You will need to log in to be recognised as a nature.com registrant) For further technical assistance, please contact our registration department For print subscription enquiries, please contact our subscription department For other enquiries, please contact our customer feedback department Nature Publishing Group | 75 Varick Street, 9th Floor | New York | NY 10013-1917 | USA Nature Publishing Group's worldwide offices: London - Paris - Munich - New Delhi - Tokyo - Melbourne San Diego - San Francisco - Washington - New York - Boston Macmillan Publishers Limited is a company incorporated in England and Wales under company number 785998 and whose registered office is located at Brunel Road, Houndmills, Basingstoke, Hampshire RG21 6XS. © 2013 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.