Melt-diffusion and ion-exchange methods: self-triggered O-rich groups on the surface of acetylene black using S-EDA solution to boost its sulfur content for lithium-sulfur batteries.

Only a few studies have described the use of H-attacking S-EDA in nucleophilic substitution reactions to bind frameworks and sulfur in cathode materials, which is also known as the ion-exchange method. The pros and cons of this method are still unclear in relation to lithium-sulfur battery applications. Here, the influences of two synthetic routes, a melt-diffusion method and H reacting with S-EDA via nucleophilic substitution, on the morphologies and electrochemical properties of cathode materials are discussed in detail based on in situ XRD and other advanced technologies.

Enhanced lithium storage performance of porous Si/C composite anodes using a recrystallized NaCl template.

Silicon (Si) has recently aroused great interest as a promising anode material for lithium-ion batteries with high energy density due to its high theoretical capacity. However, the application of Si remains a great challenge owing to its extremely large volume change during cycling, thus resulting in dramatic capacity fading. Herein, a novel structure design of the porous Si/C composite with Si nanoparticles embedded in the carbon nanosheets has been successfully achieved by using a recrystallized NaCl template with appropriate particle size.

Soluble imidazolium-functionalized coordination cages for efficient homogeneous catalysis of CO cycloaddition reactions.

A new strategy to prepare soluble homogeneous catalysts is developed by introducing imidazolium into cationic calix[4]arene-based metal-organic cages (MOCs). The soluble MOCs show high activity and recyclability in the cycloaddition reaction of CO2 without the addition of any co-catalysts. This method provides new inspiration to design highly efficient catalysts by combining the advantages of homogeneous and heterogeneous catalysis.

Diterpenoids with an unprecedented ring system from and their activities in the lysosomal-autophagy pathway.

Three novel jatrophane diterpenes, cyclojatrophanes A-C (1-3), were isolated from the seeds of Euphorbia peplus. Compounds 1-3 featured an unprecedented 5/5/5/11 tetracyclic ring system incorporating ditetrahydropyran rings. Their structures including their absolute configurations were established by extensive spectroscopic analysis, X-ray crystallographic experiments and chemical transformations.

Palladium-catalyzed dearomative cyclocarbonylation of allyl alcohol for the synthesis of quinolizinones.

An approach for the synthesis of quinolizinone with potential bioactivity has been developed via palladium-catalytic dearomative cyclocarbonylation of allyl alcohol. Diverse quinolizinone compounds could be attained with good efficiencies. A feasible reaction pathway could be a successive procedure of allylation, dearomatization, CO insertion and the Heck reaction.

High-performance flexible resistive random access memory devices based on graphene oxidized with a perpendicular oxidation gradient.

The conventional strategy of fabricating resistive random access memory (RRAM) based on graphene oxide is limited to a resistive layer with homogeneous oxidation, and the switching behavior relies on its redox reaction with an active metal electrode, so the obtained RRAMs are typically plagued by inferior performance and reliability. Here, we report a strategy to develop high-performance flexible RRAMs by using graphene oxidized with a perpendicular oxidation gradient as the resistive layer. In contrast to a homogeneous oxide, this graphene together with its distinctive inter-layer oxygen diffusion path enables excellent oxygen ion/vacancy diffusion.

Half-auxetic effect and ferroelasticity in a two-dimensional monolayer TiSe.

Two-dimensional (2D) materials with both auxetic effect and ferroelasticity are rare, however, have great application potential in next generation microelectromechanical and nanoelectronic devices. Here, we report the findings of an extraordinary combination half-auxetic effect and ferroelasticity in a single p2mm-type TiSe monolayer by performing first-principles calculations. The unique half-auxetic effect, namely the material expand laterally under both uniaxial tensile strain, and compressive strain, is reported and explained by considering both the nearest and the next-nearest interactions.

D-arginine-loaded metal-organic frameworks nanoparticles sensitize osteosarcoma to radiotherapy.

Osteosarcoma is a common type of bone cancers with a high rate of pulmonary recurrence. High-dose radiation therapy is useful for the ablation of unresectable osteosarcoma. However, it may cause severe adverse effects.

Brominated flame retardants (BFRs) in PM associated with various source sectors in southern China.

The present study investigates legacy and novel brominated flame retardants (BFRs) in atmospheric PM2.5 associated with various urban source sectors in a city and electronic waste (e-waste) recycling facilities in southern China. The concentrations of polybrominated diphenyl ethers (PBDEs) and novel BFRs (∑2NBFRs) at the urban industrial park (UIP) sites varied greatly from 22.

Water-initiated hydrocarboxylation of terminal alkynes with CO and hydrosilane.

This work discloses a Cu(ii)-Ni(ii) catalyzed tandem hydrocarboxylation of alkynes with polysilylformate formed from CO2 and polymethylhydrosiloxane that affords α,β-unsaturated carboxylic acids with up to 93% yield. Mechanistic studies indicate that polysilylformate functions as a source of CO and polysilanol. Besides, a catalytic amount of water is found to be critical to the reaction, which hydrolyzes polysilylformate to formic acid that induces the formation of Ni-H active species, thereby initiating the catalytic cycle.

The stepwise organization of nanoparticles into a Pickering emulsion.

Core/shell PVSt-b-PS@FeO composite nanoparticles (NPs) are achieved by grafting living cationic block copolymer chains onto the surface of amine-capped FeO NPs via fast termination. The number of chains grafted can be tuned via the molecular weight of PVSt-b-PS. Upon grafting PEG onto the PVSt block via a click reaction, the resulting (PVSt-g-PEG)-b-PS@FeO composite NPs become highly dispersible in water.

An oxygen-passivated vanadium cluster [V@VO] with metal-metal coordination produced by reacting V with O.

Vanadium cluster anions are highly reactive making the preparation of pure Vn- and the observation of their reactivity extremely challenging. Herein, well-resolved anionic Vn- clusters are prepared enabling an in-depth study on their reactions with O2 in the gas phase. While pure metal clusters of a magic number are not identified due to the strong V-O bonding, interestingly an unexpected oxide V11O15- was experimentally observed in surviving O2 etching reactions.

A fundamental invariant-neural network representation of quasi-diabatic Hamiltonians for the two lowest states of H.

The fundamental invariant neural network (FI-NN) approach is developed to represent coupled potential energy surfaces in quasidiabatic representations with two-dimensional irreducible representations of the complete nuclear permutation and inversion (CNPI) group. The particular symmetry properties of the diabatic potential energy matrix of H3 for the 1A' and 2A' electronic states were resolved arising from the E symmetry in the D3h point group. This FI-NN framework with symmetry adaption is used to construct a new quasidiabatic representation of H3, which reproduces accurately the ab initio energies and derivative information with perfect symmetry behaviors and extremely small fitting errors.

In-plane anisotropic 2D Ge-based binary materials for optoelectronic applications.

In-plane anisotropic two-dimensional (2D) materials possess unique in-plane anisotropic physical properties arising from their low crystal lattice symmetry. Among these low-symmetry 2D materials, anisotropic Ge-based binary materials have the advantages of simple binary and earth-abundant compositions, good stability, highly anisotropic physical properties along two principle axes, and wide coverage of bandgaps, enabling use in broadband photodetection from the infrared to ultraviolet region. Here, we review recent progress in in-plane anisotropic 2D Ge-based binary materials, focusing on their anisotropic structural, electrical and optical properties.

Modulation of destructive quantum interference by bridge groups in truxene-based single-molecule junctions.

Electron transport properties of polycyclic truxene derivatives have been investigated by the single molecule conductance measurement technique and theoretical study. Molecules with nitrogen and carbonyl substituents at the bridge sites exhibit higher single-molecule conductances by almost one order of magnitude compared with non-substituted analogues. It can be ascribed that the anti-resonance feature produced by destructive quantum interference (DQI) is alleviated and pushed away from the Fermi energy.

HiPSC-derived multi-organoids-on-chip system for safety assessment of antidepressant drugs.

The poor predictive power of existing preclinical models has spurred efforts to develop human-relevant models for accurate assessment of drug safety. In this work, we developed a multi-organoids-on-a-chip system derived from human induced pluripotent stem cells (hiPSCs), which allows for the assessment of the cardiac safety of an antidepressant drug, following liver metabolism in vitro. This liver-heart organoids-on-chip device contains compartmentalized chambers separated by a porous membrane, which permits the co-culture of 3D human liver organoids in the upper multi-well chamber and cardiac organoids in the bottom micropillar array simultaneously.

Correction: BODIPY-containing nanoscale metal-organic frameworks as contrast agents for computed tomography.

Correction for 'BODIPY-containing nanoscale metal-organic frameworks as contrast agents for computed tomography' by Tao Zhang et al., J. Mater.

Lipid metabolic adaption to long-term ambient PM exposure in mice.

Emerging evidence has demonstrated that exposure to fine particulate matter (PM) is a risk factor for lipid metabolic disorders in the liver. However, the effects of PM exposure time duration on hepatic lipid metabolism remain unknown. In this study, C57BL/6 mice were randomly divided into ambient PM (PM) or filtered air (FA) exposure chamber for short-term (4 weeks) or long-term (24 weeks) exposure via a whole body exposure system.

Research advances in integrated theranostic probes for tumor fluorescence visualization and treatment.

At present, cancer is obviously a major threat to human health worldwide. Accurate diagnosis and treatment are in great demand and have become an effective method to alleviate the development of cancer and improve the survival rate of patients. A large number of theranostic probes that combine diagnosis and treatment methods have been developed as promising tools for tumor precision medicine.

Insulating SiO under Centimeter-Scale, Single-Crystal Graphene Enables Electronic-Device Fabrication.

Graphene on SiO enables fabrication of Si-technology-compatible devices, but a transfer of these devices from other substrates and direct growth have severe limitations due to a relatively small grain size or device-contamination. Here, we show an efficient, transfer-free way to integrate centimeter-scale, single-crystal graphene, of a quality suitable for electronic devices, on an insulating SiO film. Starting with single-crystal graphene grown epitaxially on Ru(0001), a SiO film is grown under the graphene by stepwise intercalation of silicon and oxygen.

Non-Hermitian Skin Modes Induced by On-Site Dissipations and Chiral Tunneling Effect.

In this Letter, we study the conditions under which on-site dissipations can induce non-Hermitian skin modes in non-Hermitian systems. When the original Hermitian Hamiltonian has spinless time-reversal symmetry, it is impossible to have skin modes; on the other hand, if the Hermitian Hamiltonian has spinful time-reversal symmetry, skin modes can be induced by on-site dissipations under certain circumstances. As a concrete example, we employ the Rice-Mele model to illustrate our results.

A base-catalyzed domino reaction between isoindigos and α-alkylidene succinimides-convenient preparation of highly steric bispirooxindoles.

A new base promoted Michael-Michael domino cycloaddition between isoindigos and α-alkylidene succinimides has been developed for highly efficient and one-step convenient preparation of highly steric bispiroxindoles with two adjacent quaternary carbon centers and four consecutive cycles in excellent yields (up to 96%) and diastereoselectivities (up to >20 : 1) under mild conditions within a few minutes. A series of bisprooxindoles were obtained and the synthetic potential of the protocol was evaluated in a scale-up preparation.

Dual roles of underpotential deposition in the synthesis of tetrahexahedral Pd-Ag alloy nanocrystals.

Tetrahexahedral Pd-Ag alloy nanocrystals enclosed by high-index {520} facets with enhanced electrocatalytic activity have been synthesized using an Ag(i)-assisted growth protocol. The underpotential deposition of Ag plays dual roles in the formation of tetrahexahedral nanocrystals: it not only stabilizes the high-index {520} facets, but also facilitates the formation of Pd-Ag alloys.

Unexpected reversible and controllable nuclear uptake and efflux of the DNA "light-switching" Ru(ii)-polypyridyl complex in living cells via ion-pairing with chlorophenolate counter-anions.

An in-depth understanding of the mechanisms of cellular uptake and efflux would facilitate the design of metal complexes with not only better functionality and targeted theranostic efficiency, but also with controlled toxicity. Here we find, unexpectedly, that the DNA "light-switching" Ru(ii)-polypyridyl complex [Ru(phen)(dppz)] already delivered to the nucleus via ion-pairing with chlorophenolate counter-anions can gradually efflux to the cytoplasm when the cells were washed and incubated with fresh culture-medium. Interestingly, [Ru(phen)(dppz)] effluxed to the cytoplasm can be redirected back to the nucleus when the chlorophenolate counter-anions were added again.

Organocatalytic and enantioselective [4+2] cyclization between hydroxymaleimides and -hydroxyphenyl -quinone methide-selective preparation of chiral hemiketals.

A cinchona alkaloid squaramide promoted enantioselective [4+2] cyclization between hydroxymaleimides and ortho-hydroxyphenyl p-QMs has been disclosed, and a wide range of chiral hemiketals containing chromane and succinimide frameworks with two adjacent quaternary stereogenic centers have been prepared for the first time with excellent results (up to 99% yield, up to 99 : 1 dr, up to >99% ee) under mild conditions.