A new flavonol glycoside from the florets of Carthamus tinctorius L.

One new flavonol glycoside, 6-hydroxykaempferol-3-O-β-D-glucoside-7-O-β-D-glucuronide (1), together with eight known flavonoids and three known quinochalcones, was isolated from the florets of Carthamus tinctorius L. Their structures were determined by extensive spectroscopic analyses. Their cardioprotective effects against H₂O₂-induced apoptosis in H9c2 cells were also evaluated; compounds 1, 2, 4–5, 7–10 and 12 provided significant protective effects on H₂O₂-induced H9c2 cells at the concentration of 25 μg/mL.     

Electrospun‐Technology‐Derived High‐Performance Electrochemical Energy Storage Devices

Electrospinning, as a novel nontextile filament technology, is an important method to prepare continuous nanofibers and has shown its remarkable advantages, such as a broadly applicable material system, controllable fiber size and structure, and simple process. Electrospun nanofiber membranes prepared by electrospinning have shown promising applications in many fields, such as supercapacitors, lithium‐ion batteries, and sodium‐ion batteries, owing to their large specific surface area and adjustable network pore structure. The principle of electrospinning and key points relevant to its usage in the preparation of high‐performance electrochemical energy storage materials are reviewed herein based on recent publications, particularly focusing on research progress of relative materials. Also, this review describes a distinctive conclusion and perspective on the future challenges and opportunities in electrospun nanomaterials.     

Fabrication of Boron Nitride Nanosheets by Exfoliation

Nanomaterials with layered structures, with their intriguing properties, are of great research interest nowadays. As one of the primary two‐dimensional nanomaterials, the hexagonal boron nitride nanosheet (BNNS, also called white graphene), which is an analogue of graphene, possesses various attractive properties, such as high intrinsic thermal conductivity, excellent chemical and thermal stability, and electrical insulation properties. After being discovered, it has been one of the most intensively studied two‐dimensional non‐carbon nanomaterials and has been applied in a wide range of applications. To support the exploration of applications of BNNSs, exfoliation, as one of the most promising approaches to realize large‐scale production of BNNSs, has been intensively investigated. In this review, methods to yield BNNSs by exfoliation will be summarized and compared with other potential fabrication methods of BNNSs. In addition, the future prospects of the exfoliation of h‐BN will also be discussed.     

The high-sensitivity determination of protein concentrations by the enhancement of Rayleigh light scattering of Arsenazo-DBN

A new Rayleigh light scattering (RLS) assay of protein is presented in this paper. At the optimum pH 4.10, the weak RLS of Arsenazo-DBN can be greatly enhanced by the addition of proteins due to the interaction between protein and Arsenazo-DBN. Based on this, the reactions of Arsenazo-DBN and proteins, including bovine serum albumin, human serum album, gamma-globulin, egg albumin, lysozyme and trypsin, were studied. A new quantitative determination method for proteins has been developed. The linear range for human serum albumin, for example, is 0.085-34.62 micrograms mL-1 with a detection limit of 44.8 ng mL-1. Besides high sensitivity, the method is characterized by good reproducibility, rapidity of reaction, good stability, and few interfering substances. The determination of the proteins in human serum and urine samples by this method give results very close to those obtained using Coomassie Brilliant Blue G-250 colorimetry, with relative standard deviations of 0.7-2.5%.     

A supramolecular cadmium(II) complex: (1,10‐phenanthroline)[tris(2‐amino­ethyl)­amine]­cadmium(II) dinitrate hydrate

Colourless prismatic crystals of the title compound, [Cd(tren)(phen)](NO₃)₂·H₂O [phen = 1,10‐phen­an­thro­line, C₁₂H₈N₂; tren = tris(2‐amino­ethyl)­amine, C₆H₁₈N₄], form from an aqueous solution of equivalent amounts of Cd(NO₃)₂, tren and phen. Infinite one‐dimensional polymeric zigzag motifs, constructed via alternating hydrogen‐bonding and π–π interactions, are further mediated by nitrate–amine hydrogen bonds to create three‐dimensional networks.     

Synthesis of polymeric antioxidants based on ring-opening metathesis polymerization (ROMP) and their antioxidant ability for preventing polypropylene (PP) from thermal oxidation degradation

Norbornene derivatives 1-5 bearing hindered phenol groups were synthesized and undergone ring-opening metathesis polymerization (ROMP) with Grubbs 1st generation catalyst to prepare the corresponding polymeric antioxidants. After hydrogenation with p-toluenesulfonylhydrazide (TSH), polymeric antioxidants with saturated polymer chain were prepared. The resulting polymeric antioxidants were characterized by gel permeation chromatography (GPC), ¹H NMR and differential scanning calorimetry (DSC). As to polymerization activity, monomer 1 had the highest ROMP activity, while monomer 5 could not undergo homopolymerization due to the steric hindrance. The antioxidant ability of these polymeric antioxidants which was determined by oxidation induction temperature (OIT) in polypropylene (PP) system is to protect PP against thermal oxidation. Results showed that the OIT of PP increased obviously when PP was stabilized by the adding of polymeric antioxidants.     

Synthesis of ordered spiral and ring-like polypyrrole nanowires in cetyltrimethylammounium bromide crystalline suspension

Spiral dislocation morphology on the surface of cetyltrimethylammounium bromide (CTAB) crystallites has been discovered for the first time. By addition of ammonium peroxydisulfate into CTAB crystalline suspension, a drastic change in the morphology of result crystallites is observed from spiral to two dimensional (2D) islands. The spiral and 2D-island structures of these crystallites could be use as the templates for the synthesis of spiral and ring-like polypyrrole (PPy) nanowires, respectively, via direct chemical oxidative polymerization of pyrrole due to the oxidation reaction occurring preferentially at the steps of these crystallites. The mechanism of adsorption of pyrrole oligomers on the steps of these crystallites is proposed for the growth of PPy spiral and ring-like nanowires.     

A new series of dinucleating macrocyclic ligands and their complexes of zinc(II)

A new category of dinucleating macrocyclic Schiff base ligands with ring sizes from 34- to 52-membered have been synthesised employing metal template procedures involving the reaction of o-phenylenediamine with a series of α,ω-bis(3′-hydroxy-4′-formylphenyloxy)alkanes in the presence of calcium(II), barium(II) or manganese(II). The latter cations act as ‘transient’ templates for formation of the corresponding metal-free Schiff base macrocyclic ligands, H₄Lⁿ (where n signifies the number of carbons in each linking bis-alkoxy chain); the macrocycles corresponding to n = 4, 6 and 8 were isolated and characterised while, for n = 1, in which single methylene groups acts as the bridges between salicyl moieties, the cyclic product was used directly for preparation of its dinuclear complex, [Zn₂L¹], without prior isolation. Evidence for the templating role of barium in the preparation of H₄L⁶ and H₄L⁸ was obtained by isolation of the corresponding species of type H₄Lⁿ·2Ba(ClO₄)₂ (n = 6 or 8) as ‘intermediates’ before generation of the respective metal-free macrocycles. Reaction of zinc(II) acetate with the free macrocycles in methanol yielded complexes of type [Zn₂Lⁿ] in all cases. A related non-cyclic ligand, H₂L⁰ and its corresponding mononuclear complex, [ZnL⁰]·H₂O, were also synthesised and its spectral properties compared with those of the macrocyclic derivatives. The elemental analyses, ¹H NMR, IR, UV–Vis and MS spectra of the respective zinc complexes in each case were in accord with the formation of the expected 2:2 condensation product. The results of DFT calculations to probe aspects of the electronic and structural natures of both H₂L¹ and H₄L⁴ are briefly presented.     

MiR-1224-5p modulates osteogenesis by coordinating osteoblast/osteoclast differentiation via the Rap1 signaling target ADCY2

MicroRNAs (miRNAs) broadly regulate normal biological functions of bone and the progression of fracture healing and osteoporosis. Recently, it has been reported that miR-1224-5p in fracture plasma is a potential therapy for osteogenesis. To investigate the roles of miR-1224-5p and the Rap1 signaling pathway in fracture healing and osteoporosis development and progression, we used BMMs, BMSCs, and skull osteoblast precursor cells for in vitro osteogenesis and osteoclastogenesis studies. Osteoblastogenesis and osteoclastogenesis were detected by ALP, ARS, and TRAP staining and bone slice resorption pit assays. The miR-1224-5p target gene was assessed by siRNA-mediated target gene knockdown and luciferase reporter assays. To explore the Rap1 pathway, we performed high-throughput sequencing, western blotting, RT-PCR, chromatin immunoprecipitation assays and immunohistochemical staining. In vivo, bone healing was judged by the cortical femoral defect, cranial bone defect and femoral fracture models. Progression of osteoporosis was evaluated by an ovariectomy model and an aged osteoporosis model. We discovered that the expression of miR-1224-5p was positively correlated with fracture healing progression. Moreover, in vitro, overexpression of miR-1224-5p slowed Rankl-induced osteoclast differentiation and promoted osteoblast differentiation via the Rap1-signaling pathway by targeting ADCY2. In addition, in vivo overexpression of miR-1224-5p significantly promoted fracture healing and ameliorated the progression of osteoporosis caused by estrogen deficiency or aging. Furthermore, knockdown of miRNA-1224-5p inhibited bone regeneration in mice and accelerated the progression of osteoporosis in elderly mice. Taken together, these results identify miR-1224-5p as a key bone osteogenic regulator, which may be a potential therapeutic target for osteoporosis and fracture nonunion.Subject terms: Translational research, Cell signalling