Latest ArticlesMagnesium rechargeable batteries (MRBs) present opportunities for grid-scale energy storage applications as a complement to Li-ion batteries (LIBS). The major challenges are the low reversible capacity, inferior cycling stability and unsatisfactory energy densities. Na3VCr0.5Fe0.5(PO4)3 with a well-defined NASION-type structure is used as cathode in Mg cell. Two-electrons reaction (~116 mAh/g), 1.5 V average voltage and 65% of capacity retention over 100 cycles are accomplished. Mg is inserted by a biphasic reaction with the participation of V3+/V4+/V5+ redox couples in the electrochemical reaction while the non-active redox couples such as Cr3+/Cr4+ and Fe2+/Fe3+ served as stabilizer to buffer the volume variation. A thermal stability up to ~412 ℃ is also exhibited. Therefore, incorporating a mixture of three transition metal (V/Cr/Fe) in this type of structures will broaden new perspectives for realizing high performance cathodes for MRBs.
Three highly oxidized hybrid flavonoids neosophoflavonoids A–C (1, 2a, and 2b) were isolated from the roots of Sophora flavescens. Neosophoflavonoid A possesses a unique highly oxidized heptacyclic 6/6/6/6/6/6/5 system. Neosophoflavonoids B and C are isomers and share the same highly oxidized hexacyclic 6/6/6/6/6/6 systems. Their planar structures were elucidated from 1D/2D nuclear magnetic resonance (NMR), ultraviolet spectroscopy (UV), infrared spectroscopy (IR), and high resolution electrospray ionization mass spectroscopy (HRESIMS) data. Their absolute configurations were determined by thorough GIAO 13C NMR (DP4+) calculation protocol and electronic circular dichroism (ECD) calculation method. The plausible biosynthetic routes for the compounds were also proposed. All compounds exhibited significant protein tyrosine phosphatase-1B (PTP1B) inhibitory activity with half maximal inhibitory concentration (IC50) values 3.94 ± 0.01, 0.38 ± 0.13, and 0.70 ± 0.01 µmol/L, respectively. In addition, compared to a positive control fenofibrate (Feno) at 20 µmol/L, compounds 2a and 2b exhibited stronger inhibitory effects on lipid accumulation in the oleic acid (OA)-induced cell model at 5 and 10 µmol/L.
Hidden natural products are representative of defensive strategies produced in vivo in diseased plants, a process that is induced by the plant immune system. The first transcriptome library of uninfected and pathogen infected Hibiscus tiliaceus stems was constructed by transcriptome sequencing technology, genes related to cadinene-type sesquiterpenoid biosynthesis were screened and combined with ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS) analysis data, which indicated pathological tissue had potential to produce novel carbon skeletons of cadinane sesquiterpenoid dimers. Successfully, two cadinane-derived sesquiterpenoid dimers with unprecedented carbon skeletons, hibisceusanols A (1) and B (2) were isolated for the first time from the stems of H. tiliaceus induced by plant-microbial interactions. Their structures and absolute configurations were unambiguously established by spectroscopy, advanced chemistry development (ACD) and electronic circular dichroism (ECD) methods. Compounds 1 and 2 exhibited significant antitumor activity in vitro with half maximal inhibitory concentration (IC50) values of 2.3–7.2 µmol/L. The anticancer effect was generated via the induction of HepG2 cell apoptosis by inhibiting the phosphatidylinositol 3-kinase (PI3K) pathway.
Since the appearance of Rochelle salt, ferroelectrics have received extensive attention from researchers due to they are playing an important role in sensors, memories, mechanical actuation, and so on. In recent years, with the rapid development of molecular ferroelectrics, high-performance molecular ferroelectrics have become effective complement to inorganic ferroelectrics. However, compared with inorganic ferroelectrics, the family of molecular ferroelectrics is relatively scarce, and exploring high-performance ferroelectric materials through new synthesis strategies has become the trend of molecular ferroelectrics. Here, we successfully transformed non-polar material 1 (2-H2PCA)2(H2O)CdCl6 (2-H2PCA = 2-picolylamine cation) into polar material 2 (2-H2PCA)2CdCl6 by single-crystal to single-crystal transformation (SCSCT). Meanwhile, 2 exhibits clear ferroelectricity with a high-temperature Tc of 378 K, a Ps of 1.18 µC/cm2 at 300 K. This work not only realizes the purpose of synthesizing ferroelectrics by forming polar structures by SCSCT, but also realizes the reversibility of SCSCT, which provides ideas for the construction and exploration of new molecular ferroelectrics.
Deep oxidation of NO molecules to nitrate species by photocatalysis with virtually no toxic byproduct NO2 generation is a challenging task. In this study, TiO2 in-situ grows based on NH2−MIL-125(Ti) (NM-125) not only inhibited TiO2 agglomeration, but also contacted more tightly to obtain efficient interfacial effects, thus displaying excellent photocatalytic NO removal activity (68.08%). The formation of TiO2 is directly confirmed by characterizations such as X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS). Meanwhile, UV–vis, photoluminescence, and photoelectrochemical analysis indicate that TiO2 formation effectively improves the optical properties. Moreover, the strong electron interaction and electron transport direction between NM-125 and TiO2 are investigated by density functional theoretical (DFT) calculation. Finally, combined with the results of electron spin resonance (ESR) and in-situ FT-IR test, the intermediate processes of NO adsorption and photocatalytic oxidation reaction are discussed in depth, where the production of reactive oxygen species (ROS) under light is the key factor in the successful degradation of NO. Compared with NM-125 which can only produce •OH through photogenerated electrons since the lower valence band position, NMT-2 can directly produce •OH through photogenerated holes, thereby relieving the pressure on photogenerated electrons and producing more ROS. This study will provide reasonable guidance for the modification of NM-125 for photocatalytic removal of ppb-level NO.
Zinc metal is regarded as one of the most promising anodes for Zn-based batteries in next-generation energy storage systems. However, the dendrite growth and interfacial corrosion lead to poor reversibility and cycle life of Zn anodes. Herein, we synthesize a 2-phosphate-1,2,4-butane tricarboxylic acid modified hyperbranched polyamidoamine containing rich terminal groups of phosphate and carboxyl (HPC) as modified layer for the Zn anodes. Importantly, the in situ acid-etching promotes the exposure of (002)Zn plane and the generated salt-polymer complexes could be adhered to the Zn anodes tightly. This greatly favors the uniform deposition of Zn and inhibits interfacial corrosion. Consequently, stable HPC@Zn anode plating/stripping for over 1200 h at a high areal capacity of 4 mAh/cm2 and a current density of 4 mA/cm2 is obtained. This study provides a new avenue of hyperbranched polymer in interfacial design for highly reversible and stable Zn metal anodes.
Hepatocellular carcinoma is a common and fatal malignancy for which there is no effective systemic therapeutic strategy. Dihydroartemisinin (DHA), a derivative of artemisinin, has been shown to exert anti-tumor effects through the production of reactive oxygen species (ROS) and resultant mitochondrial damage. However, clinical translation is limited by several drawbacks, such as insolubility, instability and low bioavailability. Here, based on a nanomedicine-based delivery strategy, we fabricated mitochondria-targeted carrier-free nanoparticles coupling DHA and triphenylphosphonium (TPP), aiming to improve bioavailability and mitochondrial targeting. DHA-TPP nanoparticles can be passively delivered to the tumor site by enhanced penetration and retention and then internalized. Flow cytometry and Western blot analysis showed that DHA-TPP nanoparticles increased intracellular ROS, which increased mitochondrial stress and in turn upregulated the downstream Bcl-2 pathway, leading to apoptosis. In vivo experiments showed that DHA-TPP nanoparticles exhibited anti-tumor effects in a mouse model of hepatocellular carcinoma. These findings suggest carrier-free DHA-TPP nanoparticles as a potential therapeutic strategy for hepatocellular carcinoma.
Polyketide synthases (PKSs) are megasynthases with multiple autonomously folding domains, which operate cooperatively in the PKS assemblies to synthesize specific polyketide scaffolds. Any nonreactive intermediates tethered to acyl carrier protein (ACP) domain in the PKS will block the elongation process of polyketide chains. In this study, we systematically elucidate the editing function of fungal type Ⅱ thioesterases (TEIIs) to hydrolyze ACP domain-bounded nonreactive acyl groups, which are uploaded by substrate promiscuous fungal phosphopantetheinyl transferase. Thereof, the TEIIs encoded in gene clusters of nonreducing PKS with reductase domain exhibit universal editing function. Besides, editing function was also found for TEIIs encoded in gene clusters of highly-reducing PKS with condensation domain. Hence, the editing TEIIs with function of recovery PKS are applied to improve the yield of the fungal polyketides in vivo. Our study provides valuable insights into the editing process of fungal PKSs, highlights the crucial role of TEIIs in enhancing polyketide production and introduces a novel metabolic engineering strategy for fungal polyketide biosynthesis by leveraging the editing function of TEIIs.
The application of nanotechnologies in formulation has significantly promoted the development of modern medical and pharmacological science, especially for nanoparticle-based drug delivery, bioimaging, and theranostics. The advancement of engineering particle design and fabrication is largely supported by a better understanding of how their apparent characteristics (e.g., size and size distribution, surface morphology, colloidal stability, chemical composition) influence their in vivo biological performance, which raises an urgent need for practical nanoformulation methods. Based on turbulent flow mixing and the self-assembly of molecules in fluids, flash technologies emerged as effective bottom-up fabrication strategies for effective nanoformulation. Among the flash technology family, flash nanocomplexation (FNC) is considered a novel and promising candidate that can promote and optimize formulation processes in a precise spatiotemporal manner, thus obtaining excellent fabrication efficiency, reproducibility and expandability. This review presents an overview of recent advances in fabricating drug-delivery nanoparticles using FNC platforms. Firstly, brief introductions to the basic principles of FNC technology were carried out, followed by descriptions of turbulent microvolume mixers that have significantly promoted the efficiency of FNC-based fabrications. Applications of real formulation cases were then categorized according to the self-assembly-driven interactions (including electrostatic interaction, coordination interaction, hydrogen bonding and hydrophobic interaction) and discussed to reveal the progressiveness of fabricating nanoparticles and discuss how its flexibility will provide advances and replenish the philosophy of nanomedicine formulation. In the end, the commercial potential, current limitations, and prospects of FNC technology for nanoformulation will be summarized and discussed.
Dual-state emission (DSE) molecules displayed conspicuous fluorescent performance both in solid and solution states. However, the construction of DSE molecules and the regulation of their emission wavelengths remains a great challenge. Based on the structure-function relationship of quinolinonitrile-type fluorophores, this work proposed a feasible strategy for modulating their fluorescent properties into DSE via limiting the torsion angle between the quinoline ring and C=C bond in the range of 4.7° to 30°. Based on this strategy, 53 compounds were obtained which displayed tunable emission wavelengths from 397 nm to 740 nm in solid-state and from 360 nm to 672 nm in solution. The feasibility of the strategy was supported by a series of theoretical calculations, optical characterizations, and crystal analysis, suggesting the compounds have great potential in imaging living cells and tissues with desired wavelengths.