Ag Nanoparticle-Induced Surface Chloride Immobilization Strategy Enables Stable Seawater Electrolysis.

Although hydrogen gas (H ) storage might enable offshore renewable energy to be stored at scale, the commercialization of technology for H generation by seawater electrolysis depends upon the development of methods that avoid the severe corrosion of anodes by chloride (Cl ) ions. Here, it is revealed that the stability of an anode used for seawater splitting can be increased by more than an order of magnitude by loading Ag nanoparticles on the catalyst surface. In experiments, an optimized NiFe-layered double hydroxide (LDH)@Ag electrode displays stable operation at 400 mA cm in alkaline saline electrolyte and seawater for over 5000 and 2500 h, respectively.

A novel very small granular starch from Chlorella sp. MBFJNU-17.

Novel resources of very small granular starch are of great interests to food scientists. We previously found Chlorella sp. MBFJNU-17 contained small granular starch but whether the MBFJNU-17 was a novel resource of very small granular starch remained unresolved.

Dialytic Synthesis of Two-Dimensional Cu-Based Metal-Organic Frameworks for Gas Separation: Designable MOF-Polymer Interface.

We demonstrate a dialytic strategy for the synthesis of congeneric two-dimensional metal-organic framework (2D MOF) nanosheets with a dialysis membrane using 1,4-benzenedicarboxylic acid (BDC), 1,4-naphthalenedicarboxylic acid (NDC), and 9,10-anthracenedicarboxylic acid (ADC) as organic linkers and copper(II) as a metal precursor, respectively. Polyimide (PI) membranes containing these empty 2D MOF nanosheets exhibit distinct molecular sieve effects. Molecular dynamic simulation results reveal that the structures of MOF-polymer interfaces are designable by modifying the MOF interlayer distance and aperture size, which has significant influences on gas permeability and selectivity.

Rational Design of Smart Metal-Organic Frameworks for Light-Modulated Gas Transport.

Smart metal-organic frameworks (MOFs) are constructed by introducing stimuli-responsive functional groups into MOF platforms. Through membrane systems containing smart MOFs, external field-modulated gas transport can be achieved, which finds potential applications in chemical engineering. In this work, we design a series of Mg-MOF-74-III-based frameworks functionalized by arylazopyrazole groups.

Sacrificial Synthesis of Supported Ru Single Atoms and Clusters on N-doped Carbon Derived from Covalent Triazine Frameworks: A Charge Modulation Approach.

High-temperature pyrolysis of nitrogen (N)-rich, crystalline porous organic architectures in the presence of a metal precursor is an important chemical process in heterogeneous catalysis for the fabrication of highly porous N-carbon-supported metal catalysts. Herein, covalent triazine framework (CTF) and CTF-I (that is, CTF after charge modulation with iodomethane) are presented as sacrificial templates, for the synthesis of carbon-supported Ru catalysts-Ru-CTF-900 and Ru-CTF-I-900 respectively, following high-temperature pyrolysis at 900 °C under N atmosphere. Predictably, the dispersed Ru on pristine CTF carrier suffered severe sintering of the Ru nanoparticles (NPs) during heat treatment at 900 °C.

Fabricating Single-Atom Catalysts from Chelating Metal in Open Frameworks.

In the present study, a highly efficient strategy is reported using open framework platforms with abundant chelating ligands to fabricate a series of stable metal single-atom catalysts (SACs). Here, the metal ions are initially anchored onto the active bipyridine sites through postsynthetic modification, followed by pyrolysis and acid leaching. The resulting single metal atoms are uniformly distributed on a nitrogen-doped carbon (N-C) matrix.

Surface modification of porous PLGA scaffolds with plasma for preventing dimensional shrinkage and promoting scaffold-cell/tissue interactions.

Due to numerous merits, polyesters have been widely used for the preparation of porous scaffolds for biomedical applications. However, insufficient dimensional stability and weak cell interaction are two critical challenges to highly porous polyester scaffolds fulfilling their roles during applications. Here, we report the surface modification of PLGA scaffolds with air plasma for simultaneously tackling the dimensional shrinkage of PLGA scaffolds and improving scaffold-tissue integration.

Atomic Substitution Enabled Synthesis of Vacancy-Rich Two-Dimensional Black TiO Nanoflakes for High-Performance Rechargeable Magnesium Batteries.

Rechargeable magnesium (Mg) batteries assembled with dendrite-free, safe, and earth-abundant metal Mg anodes potentially have the advantages of high theoretical specific capacity and energy density. Nevertheless, owing to the large polarity of divalent Mg ions, the insertion of Mg into electrode materials suffers from sluggish kinetics, which seriously limit the performance of Mg batteries. Herein, we demonstrate an atomic substitution strategy for the controlled preparation of ultrathin black TiO (B-TiO) nanoflakes with rich oxygen vacancies (OVs) and porosity by utilizing ultrathin 2D TiS nanoflakes as precursors.

ABO blood types and postpartum depression among Chinese women: A prospective cohort study in Tianjin, China.

Postpartum depression is associated with adverse consequences for mother and offspring. The heritable ABO blood group has been associated with multiple diseases, including mental illness and diabetes. We explored the association of ABO blood group and postpartum depressive symptoms (PPDS) in a population-based cohort of pregnant Chinese women.

Unconventional O-H···C Hydrogen Bonding and Effects of Conformational Changes on Infrared Spectroscopy of o-Cresol in Solutions.

The unconventional O-H···C intramolecular hydrogen bonding and the effect of conformational changes on IR spectra of o-cresol in aqueous solutions were investigated by using molecular dynamics (MD) simulations, density functional theory (DFT), and experiments. A facial rotational isomerization between global minimum with trans conformation and the cis isomer is predicted to take place in gas phase with a low barrier of about 3.7 kcal/mol through a vertical-like transition state.

Design of [2]rotaxane through image threshold segmentation of electrostatic potential image.

An electrostatic potential (ESP)-based image segmentation method has been used to estimate the ability of proton donation and acceptance involved in ring-rod recognition. The relative binding strength of [2]rotaxane has also been further estimated from the difference of the characteristic image-segmentation derived ESP between proton donor and proton acceptor. The size and electrostatic compatibility criteria are introduced to guide the design of interlocked [2]rotaxane.

Factor Analysis of Conformations and NMR Signals of Rotaxanes: AIMD and Polarizable MD Simulations.

The interlocked ⟨rod | ring⟩ structures of pseudorotaxanes and [2]rotaxanes are usually maintained by the complex hydrogen-bonding (H-bonding) network between the rod and ring. Ab initio molecular dynamics (AIMD) using generalized energy-based fragmentation approach and polarizable force field (polar FF)-based molecular dynamics (MD) simulations were performed to investigate the conformational changes of mechanically interlocked systems and to obtain the ensemble-averaged NMR chemical shifts. Factor analysis (FA) demonstrates that the ring H-donor (2,6 pyridinedicarboxamide group) plays an important role in the ring-rod recognition.

Theoretical study on conformation dynamics of three-station molecular shuttle in different environments and its influence on NMR chemical shifts and binding interactions.

Microscopic information on conformational flexibility and macrocycle-thread binding interactions is helpful in rational design of novel multistation molecular shuttles with interesting topology and functions. Molecular dynamics (MD) was applied to simulate conformational changes of thread and macrocycle of a three-station molecular shuttle in different chemical environments (vacuum, CD3CN-CDCl3 solution, and crystal). In contrast with the highly distorted thread conformation in the gas phase and nonpolar CDCl3 solution, the solvated thread in CD3CN-CDCl3 (1:1) mix solvents exhibited a relatively rigid structure.

Dynamic self-inclusion behavior of pillar[5]arene-based pseudo[1]rotaxanes.

It was found that spontaneous isomerization takes place between three isomers of a pillar[5]arene (P5)-based pseudo[1]rotaxane. The isomerization process could be monitored by (1)H NMR spectra in polar solvent and the geometric configurations of the three isomers were further evaluated by theoretical calculations. In the threaded forms, the alkyl side chain might be preorganized by intramolecular N-HO bonds between the urea group of the side chain and the methoxy group of the P5 and further stabilized by multiple interactions, including H-bonding, C-H∙∙∙π interactions, and the steric effect of the N-Boc moiety.