Latest ArticlesBy integrating one strain-many compounds (OSMAC) and LC–MS-based molecular networking strategies, distachydrimanes A–F (1–6), six novel phenylspirodrimane dimers and hybrids representing two types of unprecedented terpenoid-polyketide hybrid skeletons, were isolated from the modified fermented rice substrate of a coral-derived fungus Stachybotrys chartarum. All the structures incorporating their absolute configurations were elucidated based on comprehensive spectroscopic analyses, mainly including HRESIMS and NMR data, single-crystal X-ray diffraction (Cu Kα), and comparison of the experimental electronic circular dichroism (ECD) data. Architecturally, compounds 1–6 represent an unprecedented class of dimeric phenylspirodrimanes with an unexpected C-18–C-23′ linkage, of which compounds 1–3 also feature an unexpected 5-methyl-1, 3-benzenediol moiety via a carbon-carbon linkage. The bioactivity assay demonstrated that compounds 1, 5 and 6 induced cell proliferation inhibition, G0/G1 cell cycle arrest, senescence and mitochondrial-mediated apoptosis in L1210 cells, highlighting their potentials as a new category of anticancer agents.
Electrocatalytic nitrogen reduction reaction (NRR) is an environmentally friendly method for sustainable ammonia synthesis under ambient conditions. Searching for efficient NRR electrocatalysts with high activity and selectivity is currently urgent but remains great challenge. Herein, we systematically investigate the NRR catalytic activities of single and double transition metal atoms (TM = Fe, Co, Ni and Mo) anchored on g-C6N6 monolayers by performing first-principles calculation. Based on the stability, activity, and selectivity analysis, Mo2@g-C6N6 monolayer is screened out as the most promising candidate for NRR. Further exploration of the reaction mechanism demonstrates that the Mo dimer anchored on g-C6N6 can sufficiently activate and efficiently reduce the inert nitrogen molecule to ammonia through a preferred distal pathway with a particularly low limiting potential of -0.06 V. In addition, we find that Mo2@g-C6N6 has excellent NRR selectivity over the competing hydrogen evolution reaction, with the Faradaic efficiency being 100%. Our work not only predicts a kind of ideal NRR electrocatalyst but also encouraging more experimental and theoretical efforts to develop novel double-atom catalysts (DACs) for NRR.
Improving the utilization of excitons has always been an important topic for the development of electroluminescence devices. In this work, we designed and synthesized three red TADF emitters TPA-DBT12, TPA-DBT3 and DTPA-DBT by employing dibenzothioxanthone (DBT) acceptor framework to stabilize the locally excited triplet state to participate in the reverse intersystem crossing (RISC) process. The fast RISC process and singlet radiation decay process gave rise to evidently enhanced exciton utilization. All of the red OLEDs based on these materials showed maximum EQE over 11% and high exciton utilization close to 100%. This work not only extend the acceptor framework for red materials but also provide a new perspective for the design of highly efficient red TADF materials with 100% exciton utilization by managing locally excited triplet state.
For more than a decade, the exfoliation of graphene and other layered materials has led to a tremendous amount of research in two-dimensional (2D) materials, among which 2D transition metal chalcogenides (TMCs) nanomaterials have attracted much attention in a wide range of applications including photoelectric devices, lithium-ion batteries, catalysis, and energy conversion and storage owing to their unique photoelectric physical properties. With such large specific surface area, strong near-infrared (NIR) absorption and abundant chemical element composition, 2D TMCs nanomaterials have become good candidates in biomedical imaging and cancer treatment. This review systematically summarizes recent progress on 2D TMCs nanomaterials, which includes their synthesis methods and applications in cancer treatment. At the end of this review, we also highlight the future prospects and challenges of 2D TMCs nanomaterials. It is expected that this work can provide the readers with a detailed overview of the synthesis of 2D TMCs and inspire more novel functional biomaterials based on 2D TMCs for cancer treatment in the future.
Clear cell renal cell carcinoma (ccRCC) is a heterogeneous malignancy with poor prognosis. Methylation of the N6 position of adenosine (m6A), the most common epigenetic modification in both messenger RNAs and noncoding RNAs, has been reported to regulate the initiation and progression of ccRCC. However, whether and how m6A-related long noncoding RNAs (m6ArlncRNAs) signify the progression of ccRCC remain unclear. We found m6ArlncRNAs are effective signatures illustrating immune landscape and risk stratification in ccRCC. We identified two differently expressed m6ArlncRNAs (DEm6ArlncRNAs), AC008870.2 and EMX2OS, as independent risk factors for overall survival of ccRCC patients, by applying stringent variable selection procedure to data from the Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma project. The risk score generated from the DEm6ArlncRNA expression categorizes patients into either high or low-risk groups, between which, enrichment analysis indicated an enrichment in immunerelated pathways. Under different DEm6ArlncRNA transcription pattern, the two risk groups differ in immune cell population composition and expression levels of therapy targeting genes. Nanoparticle is satisfactory strategy to delivering therapeutic drugs. For further clinical translation, we designed a novel nanoparticle delivery system packaged STM2457 (STM@8P4 NPs), which selectively inhibits AC008870.2- correlated m6A writer. STM@8P4 NPs loaded drug successfully with uniform particle size, long-term stability and high release efficiency. STM@8P4 NPs can easily enter ccRCC cells and showed a highly efficient ccRCC killing activity in vitro. Our results therefore indicate that m6ArlncRNAs expression can depict tumor microenvironment, predict prognosis for ccRCC patient and give hint to therapeutic strategies in ccRCC.
Breast cancer is the most prevalent cancer in women, and it was hard to prevent or diagnose at an early stage. Thus, it is imperative to develop advanced therapeutics for effective treatment. Herein, a targeted daunorubicin (DNR) and cytarabine (ara-C) co-delivery system was developed by modifying the ara-C loaded liposomes (LIP-ara-C) with the hyaluronic acid-DNR (HA-DNR) prodrugs. The co-assembled hybrid nanoparticles (HA-DNR/LIP-ara-C HNPs) exhibited good serum and storage stability with an average diameter of approximately 100 nm. By specifically binding to the CD44 receptors that overexpressed on cancer cells, these HNPs could be uptake via endocytosis and accumulate intracellularly, in which an optimized DNR and ara-C combination at a molar ratio of 1:5 could generate enhanced synergistic effects with reduced dose-related toxicity on cancer cells.
Disinfection by-products (DBPs) in water systems have attracted increasing attention due to their toxic effects. Removal of precursors (mainly natural organic matter (NOM)) prior to the disinfection process has been recognized as the ideal strategy to control the DBP levels. Currently, biological activated carbon (BAC) process is a highly recommended and prevalent process for treatment of DBP precursors in advanced water treatment. This paper first introduces the fundamental knowledge of BAC process, including the history, basic principles, typical process flow, and basic operational parameters. Then, the selection of BAC process for treatment of DBP precursors is explained in detail based on the comparative analysis of dominant water treatment technologies from the aspects of mechanisms for NOM removal as well as the treatability of different groups of DBP precursors. Next, a thorough overview is presented to summarize the recent developments and breakthroughs in the removal of DBP precursors using BAC process, and the contents involved include effect of pre-BAC ozonation, removal performance of various DBP precursors, toxicity risk reduction, fractional analysis of NOM, effect of empty bed contact time (EBCT) and engineered biofiltration. Finally, some recommendations are made to strengthen current research and address the knowledge gaps, including the issues of microbial mechanisms, toxicity evaluation, degradation kinetics and microbial products.
The random movement and easy recombination of photoinduced charges lead to a low conversion efficiency for photocatalytic hydrogen evolution. The cocatalyst design is a promising route to address such problem through introducing an appropriate cocatalyst on the semiconductor photocatalysts to construct the high-efficiency heterojunctions. Herein, novel CoS/Nb2O5 heterojunctions were constructed via in-situ loading CoS cocatalyst on the surface of Nb2O5 nanosheets. Through the femtosecond-resolved transient absorption spectroscopy, the average lifetime of charge carriers for 10 wt% CoS/Nb2O5 (159.6 ps) is drastically shortened by contrast with that of Nb2O5 (5531.9 ps), strongly suggesting the rapid charge transfer from Nb2O5 to CoS. The significantly improved charge-transfer capacity contributes to a high photocatalytic hydrogen evolution rate of 355 μmol/h, up to 17.5 times compared with pristine Nb2O5. This work would provide a new design platform in the construction of photocatalytic heterojunctions with high charge-transfer efficiency.
Construction of two RuⅢ cations and six lacunary Keggin fragments resulted in a novel Ru2W12-cluster {(RuO6)2(WO3)12(H2O)12} bridged polyoxometalate, NaH11[(RuO6)(AsW9O33)3{(W6O3)(H2O)6}]2 53H2O (NaH11·1·53H2O), which represent the largest cluster in all the Ru-containing polyoxometalates. The most interesting characteristic is that the symmetry-related Ru2W12-cluster-based hexamers contain two windmill-shaped [(RuO6)(AsW9O33)3{(W6O3)(H2O)6}] trimers or the Ru2W12 cluster was tightly wrapped by six segments of B-β-AsW9O33. The other remarkable feature is that there have one intriguing cubane structure: which is composed of the Ru(1, 2) and W(1, 28, 50, 51, 52, 53) atoms. The oxygenation reactions of anilines to azoxybenzenes was evaluated when NaH11·1·53H2O served as effective catalyst by probing various reaction. The inherent redox property of oxygen-rich polyoxometalate surfaces and high photocatalytic activity of the Ru-containing metal cluster imbedded in NaH11·1·53H2O provide sufficient driving force for the photocatalytic transformation from anilines to azoxybenzenes. The oxidation of anilines can be realized with higher selectivity to afford various azoxybenzene compounds. The durability test shows that Ru-doping catalyst displays excellent chemical stability during the photocatalytic process.
It is of great significance to develop effective antibacterial agents and methods to combat drug resistant bacterial infections due to its increasing threaten to human health and the ineffectiveness of antibiotics. Herein, a multifunctional hybrid nano-assembly (M1-Fe NPs) based on conjugated oligomer and ferrous ion was engineered with favorable bactericidal activity for synergetic antibacterial therapy. The chelation of ferrous ion not only enhances the photothermal conversion efficiency of M1 but also endows the nano-assembly with catalytic capability of transferring H2O2 into stronger oxidant hydroxyl radicals (•OH). Meanwhile, the generated heat can further promote the Fenton reaction activity. By generating cytotoxic heat and oxidative •OH, M1-Fe NPs can effectively kill Staphylococcus aureus in vitro and in vivo with the aid of low dosage of H2O2. The work provides a new multifunctional platform for combinational drug resistant antibacterial therapy and even antitumor therapy.