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Abstract Two-dimensional freestanding membranes of materials, which can be transferred onto and make interfaces with any material, have attracted attention in the search for functional properties that can be utilized for next-generation nanoscale devices. We fabricated stable 1-nm-thick hafnia membranes exhibiting the metastable rhombohedral structure and out-of-plane ferroelectric polarizations as large as 13 μC/cm2. We also found that the rhombohedral phase transforms into another metastable orthorhombic phase without the ferroelectricity deteriorating as the thickness increases. Our results reveal the key role of the rhombohedral phase in the scale-free ferroelectricity in hafnia and also provide critical insights into the formation mechanism and phase stability of the metastable hafnia. Moreover, ultrathin hafnia membranes enable heterointerfaces and devices to be fabricated from structurally dissimilar materials beyond structural constrictions in conventional film-growth techniques.

Abstract Histone H2B monoubiquitination (at Lys120 in humans) regulates transcription elongation and DNA repair. In humans, H2B monoubiquitination is catalyzed by the heterodimeric Bre1 complex composed of Bre1A/RNF20 and Bre1B/RNF40. The Bre1 proteins generally function as tumor suppressors, while in certain cancers, they facilitate cancer cell proliferation. To obtain structural insights of H2BK120 ubiquitination and its regulation, we report the cryo-electron microscopy structure of the human Bre1 complex bound to the nucleosome. The two RING domains of Bre1A and Bre1B recognize the acidic patch and the nucleosomal DNA phosphates around SHL 6.0–6.5, which are ideally located to recruit the E2 enzyme and ubiquitin for H2BK120-specific ubiquitination. Mutational experiments suggest that the two RING domains bind in two orientations and that ubiquitination occurs when Bre1A binds to the acidic patch. Our results provide insights into the H2BK120-specific ubiquitination by the Bre1 proteins and suggest that H2B monoubiquitination can be regulated by nuclesomal DNA flexibility.

The delithiation process in lithium excess cathode material of Li2MnO3 has remained unclear. Here, the authors report that delithiation is governed by the climb motion of dislocations with the aid of oxygen-release, determined directly by atomic-resolution STEM imaging and spectroscopy.

Improving the performance of Li-ion batteries relies on understanding charging/discharging mechanisms. Here the authors visualize the interfacial structure and composition of a partially delithiated lithium iron phosphate single crystal as a function of time, revealing a mechanism of relaxation.

Economic decisions are based on perceived reward value but it is unclear how individual neurons encode value estimates as input for decision mechanisms. Here authors show that dorsolateral prefrontal cortex uses a dynamic value code based on object-specific valuations by single neurons.

Nature Communications 7: Article number: 12554 (2016); Published: 13 September 2016; Updated: 23 November 2017. The previously published version of this Article contained an error in Figure 1. In panel b the x and y axis labels of the scatter graph were inadvertently inverted. This error has been corrected in both the PDF and HTML versions of the Article.