Latest ArticlesTrauma and neurosurgery often result in dural defects and are followed by serious complications or even death, finding suitable dural replacement materials to repair the defective dura has important clinical significance. Porcine peritoneal acellular matrix (PPAM) is a promising alternative material, but its poor stability makes it difficult to meet the various needs of dural reconstruction. In this work, we developed a novel antibacterial cross-linking agent oxidized quaternized guar gum (OQGG) and used it for the first time to stabilize PPAM to construct a dural mater substitute (OQGG-PPAM). The results showed that 1.5% OQGG-PPAM presented suitable mechanical property as well as good thermal stability and resistance to enzymatic degradation. It also exhibited good antibacterial activity and good anti-leakage ability. Furthermore, 1.5% OQGG-PPAM not only exhibited excellent cell compatibility but also significantly stimulated the secretion of bFGF and VEGF from seeded cells which was convenient for dural remodeling. In vivo experiment, it also exhibited the excellent histocompatibility and good anti-adhesion property. This study showed that OQGG can be used as a novel antibacterial cross-linking reagent for crosslinking natural tissues and 1.5% OQGG-PPAM was a potential candidate material for dura mater substitute.
Berberine (BBR) is the primary alkaloid compound of the heat-clearing traditional Chinese medicine Huanglian (Coptis chinensis) and exerts regulatory effects on energy metabolism. However, the specific targets and molecular mechanisms are not clear. In this paper, the BBR-affected energy metabolism pathway was screened by nontargeted metabolomics, and a BBR-derived photoaffinity labeled (PAL) probe was designed to identify potential targets via a chemical proteomics approach. NDUFV1, a subunit of complex Ⅰ on mitochondria, was identified as a potential target of BBR. In the respiratory chain, BBR suppressed the activity of complex Ⅰ, reduced the electrochemical potential in the mitochondrial intermembrane and inhibited the generation of ATP and heat via competitive binding with NDUFV1. The results illustrated the underlying mechanism of BBR in the downregulation of energy metabolism.
Rational design of electrode meterials with unique core-shell nanostructures is of great significance for improving the electrochemical performance of supercapacitors. In this work, we prepare several CuCo2O4@Ni-Co-S composite electrodes by a controllable hydrothermal and electrodeposition route. One-dimensional nanowires can shorten the ions transport path, while two-dimensional nanosheets expose many active sites. This enables three-dimensional structured composite with high electrochemical activity. The as-prepared heterostructured materials show a specific of 1048 C/g at 1 A/g. It still maintains 75.6% of initial capacity after 20000 cycles at 10 A/g. The device delivers an energy density of 79.2 Wh/kg when the power density reaches to 2280 W/kg. Moreover, it possesses an excellent mechanical stability after repeated folding at different angles
The transdermal drug delivery (TDD) shows considerable advantages over other administration pathways. However, conventional enhancing permeation methods face a series of challenges owing to barrier function provided by the skin, of which enhancing abilities either are so strong that it results in toxicity and irritation, or too weak to achieve desirable therapeutical effects. To address these issues, it is an urgent need to develop a novel method to overcome the limitations of current measures. Fortunately, in the preceding decades, ionic liquids (ILs) have been extensively studied and increasingly applied in pharmaceutical drug delivery due to their unique physicochemical and biological properties. What is more, tunability of structure resolves the challenges in processing active pharmaceutical ingredient (API) formulation, such as polymorphism and poor solubility of drugs. Thus, the presence of ILs provides an ample design space for the transdermal drug delivery system (TDDS). This review discusses the shortcomings of conventional enhancing permeation methods and introduces the application of ILs in transdermal delivery from three aspects: ⅰ) ILs are applied as enhancers to weaken the barrier function of the stratum corneum (SC). ⅱ) As counterions, ILs are combined with API to modify the physicochemical properties of drugs. ⅲ) ILs assist in the design of transdermal preparation for perfecting formulation. This review comprehensively introduces the major breakthroughs made in the applications of ILs, which can serve as guidance to provide novel ideas for formulation scientists who hit the bottleneck in the development of TDD.
The similarity of local structure-connection pattern and volumetrically compressive strain between host and guest phases can be used to stabilize heteroid metastable matter and tune the local structure and properties. Here a series of metastable ABO3 (A = Mn; B = Mn0.5Mo0.5, Mn1/3Ta2/3, and Mn0.5Ta0.5) were trapped in LiTaO3 to form solid-solutions, where the difference of solid solubility limit reveals the barrier of size effect on chemical pressure. All samples show antiferromagnetic characters, in which the (LiTaO3)1--[Mn(Mn0.5Mo0.5)O3] series exhibit more complex magnetic and dielectric behaviors with the increasing of metastable guest phase, stemming from the complex interactive mechanism between Mn2+ and Mo6+. The cell parameter variation of (LiTaO3)1--[Mn(Mn0.5Ta0.5)O3] shows a more regularly changing tendency, on account of the smallest size barrier. These findings show that chemical pressure can effectively stimulate the physical pressure to intercept and modulate a metastable phase at atomic-scale by compressibility effect between like structures at ambient pressure.
A cadmium tetracyanoplatinate host clathrate, (MV)[Cd2{Pt(CN)4}3]⋅2(H2O) (1), including a methylviologen dication (MV2+) was synthesized, and the crystal structures, photochromic and photoluminescence properties were investigated. In 1, the alternatively parallel stacking between the MV2+ dications as electron acceptors in the channels and the electron donors [Pt1(CN)4]2– units in the host frameworks give a unique donor-acceptor (DA) system. Under UV irradiation, the electron transfer between MV2+ and [Pt(CN)4]2– ions generates MV·+ radicals with a photochromic behavior from pale-yellow to blue. This process occurs through single-crystal-to-single-crystal (SCSC) transformation and obvious structure variation of viologen cations is successfully observed. Moreover, the spectral overlap between the emission bands of 1 and the absorption around 623 nm for the MV·+ radicals leads to a modulation of the photoluminescence.
The on-purpose direct propane dehydrogenation (PDH) has received extensive attention to meet the ever-increasing demand of propylene. In this work, by means of density functional theory (DFT) calculations, we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH. Interestingly, the N and P dual-coordinated single Fe (Fe-N3P-C) significantly outperform the Fe-N4C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures. The mechanistic origin of different performance on Fe-N3P-C and Fe-N4C has been ascribed to the geometric effect. To be specific, the in-plane configuration of Fe-N4 site exhibits low H affinity, which results in poor activity in CH bond activations. By contrast, the out-of-plane structure of Fe-N3P-C site exhibits moderate H affinity, which not only promote the CH bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts. This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.
Understanding phase transitions in multi-component crystals is of importance for regulating specified functional materials. Herein, we present two new organic-inorganic hybrid crystals, (Me3NCH2CH2X)4[Ni(NCS)6] (X = Cl and Br), revealing distinct phase transitions. Specifically, the Cl-substituted cations weakly interact with discrete inorganic part hence reveal step-wise dynamic changes upon heating, which result in multi-step solid-solid phase transitions (P1-P21/n–A2/a–Cmce) including a ferroelastic one with a spontaneous strain of 0.0475. Whereas the Br-substituted cations with larger steric effect prevent the solid-solid phase transition but give a solid-liquid phase transition at above 419 K. The present instances well demonstrate the complicity for multi-component crystals arising from the delicate balance established by abundant weak intermolecular interactions, and inspire the design of novel phase-transition materials by judiciously assembling multi-component crystals.
Metal-organic frameworks (MOFs) with large specific surface area, considerable pore volume, controllable structure, and high concentration of active metal sites have been applied widely in researches like catalysis and sensing. However, potential applications of MOFs in both photocatalysis and luminescence sensors are facing major challenges arising from their severe charge recombination, low utilization of solar energy, low quantum yield, limited charge transfer between the metal ions/clusters and the ligand. Recent studies revealed that rational introduction of carbon dots (CDs) with excellent optical properties, unique quantum confinement and high conductivity can greatly enhance the functions of MOFs. In this paper, typical synthesis methods of these CD-MOF composites as well as their potential applications in photocatalysis and sensing are reviewed with emphasis. Representative examples of these CD-MOF composites are discussed, and key features and advantages of CD-MOF composites that will facilitate future applications are highlighted.
Three sandwich-like [Ln2Fe2(B-α-FeW9O34)2]10− clusters (Ln2Fe4, Ln = Dy (1), Ho (2), and Y (3)) were obtained by reacting Na9[B-α-SbW9O33], Ln2O3, FeCl3·6H2O and KH2PO4. The [B-α-FeW9O34]11− units were formed via the in situ conversion of lacunary polyoxometalates (POM) [B-α-SbW9O33]9− and the Ln3+ ions were generated from the slow dissolution of Ln2O3, both of which play important roles in the synthesis of Ln2Fe4. Ln2Fe4 is the first 3d-4f cluster assembled from d-metal heteroatom-containing POM. The Dy2Fe4 cluster exhibits single-molecule magnet properties with an 80 K energy barrier in an optimal DC field. Cyclic voltammetry tests and controlled-potential coulometry experiments show that the polyoxometalate Fe heteroatom in clusters 1–3 is also electrochemically active.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
