Latest ArticlesAs a strong oxidizer, hypochlorite (ClO–) are widely employed as bleaching agents and disinfectants. Determination of ClO– is required to ensure bactericidal effects and avoid hazards caused by excessive residual chlorine. Herein, the derivative bicyclic 2-pyridone, namely DHIP-Py, was prepared successfully to establish a new ClO–-quantitative method. The probe exhibits excellent ClO– selectivity over other ROS and anions/cations, high sensitivity (LOD = 1.32 µmol/L), fast response (<5 s), and wide-pH tolerance (pH 4~10). Benefit from its good water solubility, DHIP-Py is well suited for water sample analysis and has been successfully applied to detect ClO– in real-world food and environmental samples, including tap water, bottled water and river water. The detection results were essentially identical to that of obtained from traditional DPD method. Moreover, visual detection of ClO– via filter paper-based solid sensor and imaging of ClO– in Escherichia coli were also achieved by DHIP-Py. These satisfactory results demonstrate that this bicyclic 2-pyridone-based hypochlorite probe is a promising free chlorine chemosensor with great potential for analytical applications.
Trifluoromethylation/sulfonylation of alkynes from trifluoromethyl thianthrenium triflate and sulfur dioxide under extremely mild reaction conditions provides a facile access to trifluoromethyl-substituted vinyl sulfonohydrazides in moderate to good yields. This multicomponent reaction of trifluoromethyl thianthrenium triflate, alkynes, sulfur dioxide and hydrazines proceeds efficiently under visible light irradiation in the presence of photocatalyst at room temperature with broad substrate scope and excellent functional group compatibility. This reaction is highly stereoselective, and only (E)-isomers are obtained. Additionally, these trifluoromethyl-substituted vinyl sulfonohydrazides are further evaluated for anti-bacteria activity. In vitro activities of these compounds against Staphylococcus aureus (G+) and Escherichia coli (G−) are examined.
As the main target cells of immune regulation, macrophages play an important role in the bone regeneration process. Macrophages can be polarized into the M1 and M2 types under the stimulation of different factors. They have proinflammatory and anti-inflammatory effects, respectively, and play key roles in different stages of bone regeneration. The ratio of M1 to M2 macrophages can be regulated by immunomodulatory biomaterials to promote bone repair and regeneration. In this paper, we review the recent literature on the chemical, physical and biological properties of biomaterials and the regulation of macrophage polarization under the influence of other factors. We also cover new methods for preparing immunomodulatory biomaterials for bone regeneration. This paper will provide new design ideas for the development of biomaterials with immunological properties and will support the clinical translation of bone-related medical biomaterials.
As a monoatomic bridge, fluoride ion can transmit efficient magnetic interaction between lanthanide ions but its effect on tuning the magnetization dynamics has not been well understood. Herein, two monofluoride-bridged dinuclear dysprosium complexes [Dy2F(bbpen)2(EtOH)2]Br·EtOH (1) and [Dy2F(bbppy)2]Br·2EtOH (2) with Dy-F-Dy angles of ~178° and their diamagnetic-ion diluted analogues 1´ and 2´ were synthesized. Magnetic studies reveal that 1 and 1´ barely show any magnetization dynamics, but 2 and 2´ exhibit strong magnetization dynamics. Systematical experimental analysis combined with ab initio calculations reveals that the different magnetization dynamics between 1 and 2 mainly originate from the effect of magnetic anisotropy by terminal ligand and bridging group of the chelating ligand, and the fluoride bridge can effectively suppress the quantum tunneling of the magnetization and turn on Orbach process in 2.
Sodium-ion batteries (SIBs) have received significant attention in large-scale energy storage due to their low cost and abundant resources. To obtain high-performance SIBs, many intensive studies about electrode materials have been carried out, especially the cathode material. As various types of cathode material for SIBs, a 3D open framework structural Na3V2(PO4)2F3 (NVPF) with Na superionic conductor (NASICON) structure is a promising cathode material owing to its high operating potential and high energy density. However, its electrochemical properties are severely limited by the poor electronic conductivity due to the insulated [PO4] tetrahedral unit. In this review, the challenges and strategies for NVPF are presented, and the synthetic strategy for NVPF is also analyzed in detail. Furthermore, recent developments of modification research to enhance their electrochemical performance are discussed, including designing the crystal structure, adjusting the electrode structure, and optimizing the electrolyte components. Finally, further research and application for future development of NVPF are prospected.
Voriconazole (VZL) is a second-generation and broad-spectrum triazole against fungal infections. Being a BCS (biopharmaceutics classification system) class Ⅱ compound, the poor aqueous solubility has limited its bioavailability and clinical efficacy. Aims to overcome this disadvantage, a cocrystallization strategy based on crystal engineering principles has resulted in five new multi-component crystals of VZL with maleic acid, L-tartaric, protocatechuic, gallic, and 3,5-dinitrobenzoic acids. Structure analysis revealed that the hydroxyl/carboxylic acid···triazole N3 hydrogen bonding interaction appears as a main supramolecular heterosynthon in the VZL multi-component crystals with organic acids. And VZL molecule has a flexible conformation in each of the five multi-component structures. The newly synthesized multi-component crystals showed impressive solubility improvement compared to that of the raw material of VZL. Molecular electrostatic potential surfaces (MEPS) analysis based on density functional (DFT) calculations revealed that hydrogen bond interactions in cocrystals mainly involved pairwise interactions in the global maxima and minima sites, but this rule is not always followed. This study indicates the potential of cocrystals to improve the solubility and dissolution rate of VZL
Two bis-naphthalimide-based supramolecular gelators (NN-3 and NN-4) with a little difference of position of amino groups were designed and synthesized for the detection of oxaloyl chloride and phosgene. Energy transfer could be occurred between two naphthalimide groups in molecules NN-3 and NN-4. Yellow gels NN-3 and NN-4 were formed in some mixed solvents, and nanofibers with different size were obtained in these gels. The self-assembly processes of NN-3 and NN-4 in different solvents were investigated by UV-vis absorption, fluorescent spectra, SEM, FTIR, XRD and NMR. Gelators NN-3 and NN-4 could selectively detect oxaloyl chloride in solution and film states, but detect phosgene only in solution. NN-3 exhibited the ratiometric detection ability towards oxaloyl chloride and phosgene with the low limit of detection (LOD) of 210 nmol/L and 90 nmol/L, respectively. NN-4 as the corresponding control sample, it owned the higher LOD towards oxaloyl chloride and phosgene of 12.4 µmol/L and 64 µmol/L, respectively. Interestingly, films NN-3 and NN-4 could sensitively detect oxaloyl chloride gases with the low LOD of 2.0 ppm and 8.34 ppm, respectively. The detection mechanisms of NN-3 and NN-4 were well studied by 1H NMR titration, HRMS and theoretical calculation.
Nitrogen electro-reduction reaction (NERR) is a promising alternative method for ammonia production to the Haber–Bosch approach due to mild reaction conditions and free harmful by-product emission. A formidable challenge in bringing NERR closer to the practical application is developing an electro-catalyst which can simultaneously improve the Faraday efficiency and reduce the reaction over-potential. Herein, we fabricated a catalyst of nitrogen-doped carbon dots modified copper-phosphate nanoflower petals (CuPo-NCDs NF) via a self-assembly method. The flower structure endowed the CuPo-NCDs NF with large specific surface area, and thus enabled more active sites to be exposed. In particular, we demonstrated that the NCDs modified CuPo petals with flower-like structure can accelerate the interfacial proton-electron transfer, suppressing the competing hydrogen evolution reaction and promoting the desired NERR process. Ultimately, for the CuPo-NCDs NF catalyzed NERR, the FENH3 and the reaction potential both were boosted, the resultant energy efficiency of NERR reached a record-breaking value of 56.5%, and the NH3 yield rate increased by 7 times compared to NCDs. This study provides a novel catalyst with a new pathway to boost the NERR.
The Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) layered cathodes endow Li-ion batteries (LIBs) with high energy density. However, they usually suffer from limited ion-diffusion and structural instability during cycling. Although doping strategy can effectively alleviate these issues, the coupling effects of multi-element doping and the corresponding performance enhancement mechanism have been yet unclear. Here, we report a Zr/Ti dual-doped NCM811 cathode material (ZT-NCM811), in which Zr-ion is doped into both transition metal (TM) layers and lithium layers and Ti-ion is only distributed in TM layers. The dual-doping can effectively enhance crystal structure stability via inhibiting the lattice collapse along c-axis and decreasing the Li/Ni disorder. Meantime, the lattice oxygen escape is also greatly reduced due to the presence of stronger Zr-O and Ti-O bonds, further mitigating the crystal surface parasitic reactions with electrolyte. The resultant ZT-NCM811 exhibits high specific capacity of 124 mAh/g at even 10 C, much higher than undoped and single-doped NCM811, and a retention of 98.8% at 1 C after 100 cycles. The assembled ZT-NCM811/graphite full cell also delivers superior battery performances and durability.
Various phototheranostics have recently been developed for phototherapy. Through proper molecular design, the photochemical and photophysical properties of these phototheranostics can be promoted. Herein, an acceptor-donor-acceptor (A-D-A)-structured dye, BTP-4F-DMO, was synthesized and prepared into water-soluble nanoparticles (NPs). The obtained BTP-4F-DMO NPs had strong absorption from 650 nm to 850 nm and a fluorescence emission peak at ~900 nm that tailed to ~1100 nm. The NPs showed a superhigh photothermal conversion efficiency of 90.5% ± 5% and could simultaneously generate •OH and 1O2 with a 1O2 generation quantum yield of 4.6% under 808 nm laser irradiation. Due to these advanced properties, BTP-4F-DMO NPs can switch the role of autophagy from pro-survival to pro-death, thereby further promoting cancer cell death. These features make BTP-4F-DMO NPs a promising multifunctional phototheranostic agent for NIR-Ⅱ fluorescence/photoacoustic dual-mode imaging-guided synergetic photodynamic/photothermal therapy. In general, this work provides a strategy for expanding the biomedical applications of organic A-D-A-structured phototheranostics.