Articles

Epimerization of carbohydrates to rare sugars yields products that have potential applications as anti-viral drugs or chiral building blocks. Here, Sn-Beta zeolite in the presence of sodium tetraborate is shown to catalyze the selective epimerization of aldoses in aqueous media.

Platinum is used as a cathode in fuel cells but undergoes dissolution during potential changes, hindering commercial application in electric vehicles. Sasakiet al.report a new class of stable electrocatalysts that consist of platinum monolayers on palladium–gold alloy nanoparticles.

Mutations in human angiogenin are implicated in the progression of amyotrophic lateral sclerosis. Thiyagarajan and colleagues show that structural differences between angiogenin variants affect neuronal survival, and the ability to induce stress granules in neuronal cell lines.

Interactions of cells with extracellular matrix are important in normal physiology and cancer metastasis. Here, an extracellular matrix molecule array is developed and used to show that conserved changes in adhesive properties are associated with metastasis, including binding to fibronectin in combination with galectin-3, galectin-8 or laminin.

Self-assembly of DNA can provide access to a range of nanoscale structures, but assembly using magnesium has been considered essential. Martin and Dietz report conditions that allow the assembly of templated, multi-layer DNA structures in the presence of monovalent ions, rather than magnesium.

Spider webs consist of scaffolding silk, which supports the cobweb, and gumfoot silk, which can detach easily from the web upon contact with prey. Here, these different mechanical demands are shown to be met by silk attachments of two distinct architectures using the same pyriform silk secretions.

Strain in Si nanostructures is used to achieve higher carrier mobility, making these devices candidates for the next generation of transistors. Minamisawaet al. fabricate silicon nanowires subject to elastic tensile strain up to 4.5%, exceeding the limit achievable with the use of SiGe virtual substrates.

Linear magnetoresistance is a phenomenon observed in many material systems and could be used in magnetic field sensors. This paper uncovers its microscopic origin showing how it arises from multiple scattering of electrons by low-mobility islands within an inhomogeneous high-mobility semiconductor.

Flexible electronic devices are widely considered to have significant potential for a range of applications. Here the authors present a bendable and transparent memory based on graphene electrical contacts and silica as the memory element.

Cavity optomechanics can exploit optical forces to achieve all-optical signal processing, but most schemes are limited to a narrow wavelength range. Using a cavity optomechanical design system with two optical channels, Liet al. show broadband readout and all-optical amplification of radio-frequency signals.

Autoreactive T cells are eliminated as they encounter self-antigens during transit through the thymus. Uedaet al. reveal that mice lacking the Hippo homologue Mst1 develop autoimmunity as a result of impaired integrin-dependent T cell migration through this negatively selective niche.

Endothelial cells provide a vital barrier system to the passage of water and ions but not large plasma proteins. Using fluorescently labelled dextrans, the authors show that regions of high or low adherens junction density differentially restrict the passage of molecules up to 70 kDa in size.

Sodium-gated ion channels open and close in response to the flow of ions. Here, McCusker et al.report the open structure of a sodium-gated ion channel pore from a bacterial homologue, and show, by comparison with the closed structure, that the movement of a C-terminal helix is sufficient to open the channel.

Protein encapsulation in molecular cages has the potential to alter protein function and aid crystallization. Here, ubiquitin is encapsulated within a giant coordination cage; the protein is attached to a bidentate ligand, and the cage self-assembles upon addition of capping ligands and Pd(II) ions.

In the inner ear, sound waves produce movements in hair cell sterocilia, triggering the opening of ion channels. Hakizimana and colleagues show that the resultant currents change the length of sterocilia, and that these length changes alter the efficiency by which sound is converted into electrical signals.

Ultrafast demagnetization occurs when magnetically ordered solids are exposed to femtosecond light pulses, yet the exact spin-transfer mechanism is still debated. Combining ultrashort X-rays and infrared laser pulses, Pfauet al. show the importance of spin transport between domains in thin magnetic films.

Causal order is a concept that is engrained in the standard understanding of time, both in classical and quantum mechanics. Oreshkovet al.generalize the standard formalism of quantum theory to a framework with no pre-existing causal order, and find a new class of correlations that have no analogue in the classical world.

The design of chemical photoswitches could potentially lead to the development of novel therapeutics that regulates neurotransmission. In this study, a light-sensitive modified derivative of propofol is shown to activate GABA_A receptors in Xenopusoocytes, rat ganglion cells and mouse cerebellar slices.

T- and X-shaped polyphilic liquid crystals can generate ordered structures with potential nanotechnology applications. Here, the inability of polyphiles to achieve optimal packing and complete nanophase separation is exploited to produce a flexible two-dimensional honeycomb with giant octagonal and square cylinders.

The analysis of food web properties under different environmental conditions informs us how the ecosystem functions. Here, Tunneyet al. use post-glacial lakes as model ecosystems to show how macroscopic patterns of food webs vary with changes in habitat and resource accessibility.