Articles

Topological insulators are a class of materials with an unusual band structure that makes them metallic at the surface and insulating in the bulk. Okamoto and co-workers use electronic structure calculations to predict a new family of possible topological insulators based on transition-metal oxides.

Prenucleation clusters have been observed during the early stages of calcium carbonate formation, contrary to classical models. Here, computer simulations indicate that the clusters are composed of an ionic polymer with alternating calcium and carbonate ions, and a dynamic topology of chains, branches and rings.

The half-life of IgG is regulated by binding to the neonatal Fc receptor and, in the case of IgG3, is reduced compared to other IgG proteins. In this study, a mutation in IgG3 is shown to reduce binding to the neonatal Fc receptor, which can be competitively blocked by IgG1.

Optical vortex traps are appealing for handling delicate particles, but conventional techniques are challenging with objects smaller than the diffraction limit of light. By exploiting plasmonic resonances in gold diabolo nanoantennas, Kanget al. demonstrate low-power vortex trapping of nano-scale objects.

Biomass-derived monomers are a renewable resource for the production of polymers. Robertet al. develop an auto-tandem catalytic transformation for the synthesis of aliphatic polyesters—'activated' monomers are prepared from dicarboxylic acids, which can be copolymerized with epoxides.

The modification of proteins with O-linked-N-acetylglucosamine causes regulation of multiple cellular processes. In this study, Sakaidani and colleagues identify an endoplasmic reticulum O-linked-N-acetylglucosamine transferase in Drosophilathat regulates the adhesion of epithelial cells to the extracellular matrix.

Encephalization—increase of brain size relative to body size—has occurred in two distinct evolutionary lineages; Neanderthals and modern humans. However, the 3D endocranial surface shape analysis reported here reveals unique structures at the base of the brain inHomo sapiens, which may have contributed to learning and social capacities.

Mid-infrared semiconductor lasers suffer from a high threshold power density, but interband cascade lasers may offer a more efficient alternative. Here, theory and experiments on such emitters demonstrate remarkably low thresholds and power consumption compared to state-of-the-art quantum cascade lasers.

Genome-scale metabolic models for bacterial species allow a systematic study of inter-species interactions. Here, competitive and cooperative potential is predicted between 6,903 pairs of species, to explore the role of these interactions in shaping coexistence patterns in natural communities.

Optical imaging and spectroscopy rely on understanding how light enters and propagates through turbid media, yet its behaviour near the point-of-entry has remained elusive. Now Vitkinet al. report an analytical solution to this problem and demonstrate its agreement with simulations and experiments.

Active shortening in the Central Andes shifted from the western to the eastern margin between 10-7 Myr ago, but the mechanism of formation is still unclear. Here, using critical wedge theory and local-scale fault friction calculations, this shift is proposed to have been controlled by changes in erosion patterns.

The unique band structure of topological insulators gives rise to insulating bulk and unusual metallic surface properties. By tuning the content of Sb in the ternary compound (Bi_1–xSb_x)₂Te₃, Wang and collaborators show it is possible to control the precise features of the band structure in a continuous fashion.

Unlike the other iron-based superconductors, the parent compounds of the alkaline iron selenide superconductors are insulators. Dai and colleagues examine the spin-wave excitations in these materials and uncover evidence for a common magnetic origin for all iron-based superconductors.

Magnetic resonance force microscopy is a scanning probe technique capable of detecting and imaging electron spins. Vinanteet al.bring the operating temperature of this method into the millikelvin temperature regime, revealing spin diffusion phenomena that were hitherto inaccessible.

Nanomechanical resonators are attractive as ultra-low concentration sensors of biomolecules, as their small scale allows for sensitive mass detection. Here, using a nanowire array as part of a photonic crystal, such a device is presented for light trapping, absorption and low-concentration sensing.

The night sky viewed from Earth is very bright at infrared wavelengths due to atmospheric emission, making land-based astronomy difficult in this spectral region. Here, a photonic filter is demonstrated to suppress this unwanted light, opening new paths to infrared astronomy with current and future telescopes.

Herpesvirus glycoprotein D binds to nectin 1 and the herpes virus entry mediator protein on the surface of host cells. In this study, Zhanget al. report the crystal structure of glycoprotein D in complex with the immunoglobulin-like domains of nectin 1, which suggests that binding of glycoprotein D to nectin 1 prevents nectin 1 dimerization.

Quantum objects are subject to decoherence effects due to the surrounding environment. This study demonstrates experimentally a counterintuitive example of anomalous decoherence, in which electron spins residing at nitrogen vacancy centres in diamond display longer coherence times under stronger noises.

Chiral liquid crystals of two-dimensional colloids have not been extensively investigated. Xu and Gao show that graphene oxide can form chiral liquid crystals, and demonstrate that they can be spun into macroscopic fibres, and that subsequent chemical reduction provides graphene fibres with high conductivity.

Activin is known to have a role in wound healing, but its role in skin cancer is unknown. Antsiferovaet al. show that activin is elevated in human skin tumours, and by modulating epidermal immune cells, exacerbates tumour progression in a mouse model of skin cancer.