Dual light-responsive shape transformations of a nanocomposite hydrogel sheet enabled by etching shaped plasmonic nanoparticles.

We report here on dual shape transformations of the same thermo-responsive hybrid hydrogel sheet under irradiation of a laser with two different wavelengths (808 nm and 450 nm). By etching the silver nanoprisms in the sheet to silver nanodiscs by using chloride ions (Cl), two areas with distinct light extinction properties are integrated in a single sheet. The conversion of photon energy to thermal energy in local areas by the silver nanoprisms or nanodiscs under laser irradiation with an appropriate wavelength heats up the sheet locally and causes a local volumetric shrinkage, and hence a volumetric mismatch in different areas in the sheet.

[Anti-diabetic active constituents of pomegranate peel-derived extracellular nanovesicles].

Pomegranate peel-derived extracellular nanovesicles(PPENs) were isolated and purified by ultra-high speed centrifugation and sucrose density gradient centrifugation. Their morphology and structure were characterized. In vitro α-glucosidase inhibition assay and model test of insulin resistance(IR) in HepG2 cells showed that PPENs had good anti-diabetic activity.

A phosphatase-like nanomaterial promotes autophagy and reprograms macrophages for cancer immunotherapy.

Macrophages are plastic and play a key role in the maintenance of tissue homeostasis. In cancer progression, macrophages also take part in all processes, from initiation to progression, to final tumor metastasis. Although energy deprivation and autophagy are widely used for cancer therapy, most of these strategies do not target macrophages, resulting in undesired effects and unsatisfactory outcomes for cancer immunotherapy.

[Three new cucurbitane-type triterpenoid glycosides from Citrullus colocynthis and their anti-inflammatory activity].

Three new cucurbitane-type triterpenoid glycosides were separated from the ethyl acetate extract of Citrullus colocynthis by a variety of chromatographic techniques. According to the data of NMR, HR-ESI-MS, and/or comparison with the reported data, the three novel cucurbitane-type triterpenoid glycosides were identified as colocynthenin E(1), colocynthenin G(2), and colocynthenin H(3). The cell inflammation model was established with RAW264.

[Chemical constituents from Callicarpa kwangtungensis and their hemostatic activities].

This study aims to identify the chemical constituents from Callicarpa kwangtungensis and determine their activities. MCI, ODS, and Sephadex LH-20 chromatography and semi-preparative HPLC were employed to separate the chemical constituents. A total of 15 compounds were separated, and their structures were identified on the basis of spectroscopic analysis and comparison with the data in relevant literature.

Cascade nanozymatic network mimicking cells with selective and linear perception of HO.

A single stimulus leading to multiple responses is an essential function of many biological networks, which enable complex life activities. However, it is challenging to duplicate a similar chemical reaction network (CRN) using non-living chemicals, aiming at the disclosure of the origin of life. Herein, we report a nanozyme-based CRN with feedback and feedforward functions for the first time.

Theoretical prediction on net boroxene as a promising Li/Na-ion batteries anode.

Novel two-dimensional (2D) electrode materials have become a new frontier for mining electrode materials for Li-ion batteries (LIBs) and Na-ion batteries (NIBs). Herein, based on first-principles calculations, we present a systematic study on the Li and Na storage behaviors in Calypso-predicted completely flat 2D boron oxide (l-BO) with large mesh pores. We start our calculations from geometrical optimization, followed by a performance evaluation of Li/Na adsorption and migration processes.

[Meroterpenoids from Rhododendron nivale].

To elucidate the chemical material basis of Rhododendron nivale, this study comprehensively used various chromatographic techniques to isolate and obtain five new meroterpenoid enantiomers(1a/1b-5a/5b) from the ethyl acetate extract of R. nivale. A variety of spectral analytical methods, such as high-resolution mass spectrometry(HRMS), nuclear magnetic resonance spectroscopy(NMR), and infrared(IR) spectrum, were used to evaluate the structure, combined with the measurement and calculation of electronic circular dichroism(ECD).

Defect and strain engineered MoS/graphene catalyst for an enhanced hydrogen evolution reaction.

Molybdenum disulfide (MoS) has been demonstrated as a promising non-precious metal electrocatalyst for the hydrogen evolution reaction (HER). However the efficiency of the HER falls short of expectations due to the large inert basal plane and poor electrical conductivity. In order to activate the MoS basal plane and enhance the hydrogen evolution reaction (HER) activity, two strategies on the hybrid MoS/graphene, including intrinsic defects and simultaneous strain engineering, have been systematically investigated based on density functional theory calculations.

Preparation and lithium storage of core-shell honeycomb-like CoO@C microspheres.

Core-shell honeycomb-like CoO@C microspheres were synthesized a facile solvothermal method and subsequent annealing treatment under an argon atmosphere. Owing to the core-shell honeycomb-like structure, a long cycling life was achieved (a high reversible specific capacity of 318.9 mA h g was maintained at 5C after 1000 cycles).

Nano/micrometer porous conductive network structure LiTiO@C/CNT microspheres with enhanced sodium-storage capability as an anode material.

LiTiO@C/CNT microspheres, wherein CNTs were firmly anchored to LiTiO@C nanoparticles, were prepared a facile spray drying method and subsequently annealed in an argon atmosphere, exhibiting long cycling stability (charge/discharge capacities of 85.45/86.18 mA h g after 500 cycles at 500 mA g) and excellent rate capability (charge capacity of 61.

[Hydrolyzable tannins from flowers of Punica granatum and their anti-diabetic activities].

To investigate the active components against diabetes, the present study isolated eight hydrolyzable tannins from the ethyl acetate extract of Punica granatum flowers by MCI, reversed-phase chromatography(ODS), Sephadex LH-20 chromatography, and HPLC, and the structures were elucidated as 1-O-galloyl-6-O-feruloyl-β-D-glucose(1), 1,2,3,4,6-penta-O-gally-β-D-glucopyranose(2), punicafolin(3), corilagin(4), telimagrandin Ⅰ(5), 1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-β-D-glucose(6), heterophylliin A(7), and eugeniin(8) on the basis of spectral data and literature records. Among them, compound 1 is a new compound, and compounds 5-8 were isolated from this species for the first time. All isolated compounds were tested for inhibitory activities against α-glucosidase and DPP-Ⅳ.

[Secondary metabolites of endophyte Hypoxylon sp. HD-2014 from Uncaria rhynchophylla].

This study aims to investigate the compounds in the product of rice fermented with endophyte Hypoxylon sp.HD-2014 from Uncaria rhynchophylla.To be specific, normal-phase, MCI, Sephadex LH-20, and semi-preparative high performance liquid chromatography(HPLC) was used to yield 12 compounds.

I-mediated Csp-P bond formation tandem cyclization of -alkynylphenyl isothiocyanates with organophosphorus esters.

A novel, I-mediated tandem cyclization of -alkynylphenyl isothiocyanates with organophosphorus esters has been developed under mild conditions. Different kinds of 4-benzo[][1,3]thiazin-2-ylphosphonate could be synthesized in moderate to excellent yields. This method has the advantages of easy access to raw materials, free-metal catalyst, simple operation, high yield and high functional group tolerance.

Highly selective generation of singlet oxygen from dioxygen with atomically dispersed catalysts.

Singlet oxygen (O) as an excited electronic state of O plays a significant role in ubiquitous oxidative processes from enzymatic oxidative metabolism to industrial catalytic oxidation. Generally, O can be produced through thermal reactions or the photosensitization process; however, highly selective generation of O from O without photosensitization has never been reported. Here, we find that single-atom catalysts (SACs) with atomically dispersed MN sites on hollow N-doped carbon (M/HNC SACs, M = Fe, Co, Cu, Ni) can selectively activate O into O without photosensitization, of which the Fe/HNC SAC shows an ultrahigh single-site kinetic value of 3.

Transition-metal-free synthesis of aryl 1-thioglycosides with arynes at room temperature.

A mild, convenient and transition-metal-free protocol for the synthesis of aryl 1-thioglycosides is presented arynes generated combined with glycosyl thiols in the presence of TBAF(BuOH). The methodology provides a general and efficient way to prepare a series of functionalized thioglycosides in good to excellent yields with a perfect control of the anomeric configuration at room temperature. In addition, the reaction conditions tolerate a variety of the pentoses and hexoses, and the reaction also performs smoothly on protected monosaccharides and disaccharides.

A GGA + U investigation into the effects of cations on the electromagnetic properties of transition metal spinels.

Spinel oxides are promising low-cost catalysts with manifold and controllable physicochemical properties. Trial and error strategies cannot achieve the effective screening of high-performance spinel catalysts. Therefore, unraveling the structure-performance relationship is the foundation for their rational design.

Electrochemical oxidative N-H/P-H cross-coupling with H evolution towards the synthesis of tertiary phosphines.

Tertiary phosphines(iii) find widespread use in many aspects of synthetic organic chemistry. Herein, we developed a facile and novel electrochemical oxidative N-H/P-H cross-coupling method, leading to a series of expected tertiary phosphines(iii) under mild conditions with excellent yields. It is worth noting that this electrochemical protocol features very good reaction selectivity, where only a 1 : 1 ratio of amine and phosphine was required in the reaction.

Confinement synthesis in porous molecule-based materials: a new opportunity for ultrafine nanostructures.

A balance between activity and stability is greatly challenging in designing efficient metal nanoparticles (MNPs) for heterogeneous catalysis. Generally, reducing the size of MNPs to the atomic scale can provide high atom utilization, abundant active sites, and special electronic/band structures, for vastly enhancing their catalytic activity. Nevertheless, due to the dramatically increased surface free energy, such ultrafine nanostructures often suffer from severe aggregation and/or structural degradation during synthesis and catalysis, greatly weakening their reactivities, selectivities and stabilities.

A single-atom Cu-N catalyst eliminates oxygen interference for electrochemical sensing of hydrogen peroxide in a living animal brain.

Hydrogen peroxide (HO) plays essential roles in various physiological and pathological processes. The electrochemical hydrogen peroxide reduction reaction (HPRR) has been recognized as an efficient approach to HO sensing; however, the HPRR has always suffered from low tolerance against the oxygen reduction reaction (ORR), resulting in poor selectivity of the HPRR-based sensing platform. In this study, we find that the electrochemical HPRR occurs preferentially compared to the ORR when isolated Cu atoms anchored on carbon nitride (Cu/CN) are used as a single-atom electrocatalyst, which is theoretically attributed to the lower energy barrier of the HPRR than that of the ORR on a Cu/CN single-atom catalyst (SAC).

Electrochemically selective double C(sp)-X (X = S/Se, N) bond formation of isocyanides.

The construction of C(sp)-X (X = B, N, O, Si, P, S, Se, .) bonds has drawn growing attention since heteroatomic compounds play a prominent role from biological to pharmaceutical sciences. The current study demonstrates the C(sp)-S/Se and C(sp)-N bond formation of one carbon of isocyanides with thiophenols or disulfides or diselenides and azazoles simultaneously.

[Four new lanostane triterpenoids from latex of Euphorbia resinifera].

Four new lanostane triterpenoids, 3β-hydroxy-12α-methoxylanosta-7,9(11),24-triene(1), 3β-hydroxy-12α-methoxy-24-methylene-lanost-7,9(11)-dien(2), 3,7-dioxo-lanosta-8,24-diene(3), and 3,7-dioxo-24-methylene-lanost-8-en(4), were isolated from the latex of Euphorbia resinifera with a variety of chromatography methods. Their structures were elucidated based on spectroscopic data and/or comparison with the data reported in previous research. Compounds 1, 2, and 4 showed moderate inhibition of LPS-induced NO production by RAW264.