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Objective To explore the effect of FBXW7 on ferroptosis in head and neck squamous cell carcinoma. Methods Head and neck squamous cell lines HN4 and HN6 were cultured in vitro. FBXW7 and SOX2 overexpression plasmids were constructed, and the plasmids were stably transfected into cell lines. The overexpression transfection efficiency was verified at the transcription level and protein level by qRT-PCR and Western blot experiments, respectively. The lipid peroxidation levels of head and neck squamous cell carcinoma cells with overexpressing FBXW7 were verified by measuring malondialdehyde(MDA), glutathione(GSH), and reactive oxygen species(ROS) levels. After treating cells with ferroptosis inhibitor Fer-1, the changes in cell viability were further detected to verify the effect of FBXW7 on ferroptosis. The effect of transfection of the overexpressed plasmid on cellular pathways was detected by Western blot. Results HN4 and HN6 cell lines showed increased levels of lipid peroxidation after overexpression of FBXW7, and the ferroptosis inhibitor Fer-1 was able to effectively reverse the ferroptosis induced by overexpression of FBXW7. Western blot assay results showed that overexpression of FBXW7 reduced the expression of c-Myc, SOX2 and SLC7A11. Conclusion FBXW7 regulates the expression of SOX2-SLC7A11 by degrading c-Myc, thereby effectively regulating ferroptosis in HNSCC.

Skeletal reorganization reactions have emerged as an intriguing tool for converting readily available compounds into complicated molecules inaccessible by traditional methods. Herein, we report a unique skeleton‐reorganizing coupling reaction of cycloheptatriene and cycloalkenones with amines. In the presence of Rh/acid catalysis, cycloheptatriene can selectively couple with anilines to deliver fused 1,2‐dihydroquinoline products. Mechanistic studies indicate that the retro‐Mannich type ring‐opening and subsequent intramolecular Povarov reaction account for the ring reorganization. Our mechanistic studies also revealed that skeleton‐reorganizing amination between anilines and cycloalkenones can be achieved with acid. The synthetic utilization of this skeleton‐reorganizing coupling reaction was showcased with a gram‐scale reaction, synthetic derivatizations, and the late‐stage modification of commercial drugs. [ABSTRACT FROM AUTHOR]

Five-carbon dimethylallyl units, such as prenyl and reverse-prenyl, are widely distributed in natural indole alkaloids and terpenoids. In conventional methodologies, these valuable motifs are often derived from substrates bearing leaving groups, but these processes are accompanied by the generation of stoichiometric amounts of by-products. From an economical and environmental point of view, the basic industrial feedstock isoprene is an ideal alternative precursor. However, given that electronically unbiased isoprene might undergo six possible addition modes in the coupling reactions, it is difficult to control the selectivity. This article summarizes the strategies we have developed to achieve regioselective C–H functionalizations of isoprene under transition-metal and acid catalysis. 1 Introduction 2 Catalytic Coupling of Indoles with Isoprene 3 Catalytic Coupling of Formaldehyde, Arenes and Isoprene 4 Catalytic Coupling of 4-Hydroxycoumarins with Isoprene 5 Catalytic Coupling of Cyclic 1,3-Diketones with Isoprene 6 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

The rational design of the microporous layer (MPL) is very important for the water management of proton exchange membrane fuel cells (PEMFC). The uncertainty of pore structure distribution of MPL originated from the random stacking of particles. To facilitate the water transfer at high current density, it is necessary to improve the capillary force of the gas diffusion layer (GDL). The hierarchical porous structure MPL was designed by coating carbon nanotubes (CNTs) with different length-diameter ratios. In the process of constructing the network structure of CNTs, the polyvinylidene fluoride (PVDF)/N-methylpyrrolidone binder/solvent system alleviates the structural and performance defects caused by the agglomeration via an integrated method of dispersion and binding. The optimal current density of PEMFC at 0.2 V can reach 1913.8 mA/cm2 under the optimal MPL structure. The peak power density of GDL-G PVDF prepared with PVDF is 831.8 W/cm2 which is 8.85% and 15.74% higher than that of GDL-1 PVDF and GDL-2 PVDF with single pore structure, respectively. The lowest mass transfer resistance of GDL-G PVDF is 23.71 mΩ, indicating that it can discharge excess water at the catalyst layer/MPL interface to avoid flooding. This design provided a novel strategy for the stable operation of PEMFC at high current density. [Display omitted] • Two types of carbon nanotubes were used to construct MPL with hierarchical network structure. • Enhanced performance of PEMFC was achieved through enhancing capillary pressure. • The optimized properties of MPL ensure ultra-low mass transport resistance. • The MPLs with PVDF/NMP binder/solvent system facilitate the water and gas transport. [ABSTRACT FROM AUTHOR]

Background: Accurate preoperative prediction of lymph node metastasis (LNM) in esophageal cancer (EC) patients is of crucial clinical significance for treatment planning and prognosis., Aim: To develop a clinical radiomics nomogram that can predict the preoperative lymph node (LN) status in EC patients., Methods: A total of 32 EC patients confirmed by clinical pathology (who underwent surgical treatment) were included. Real-time fluorescent quantitative reverse transcription-polymerase chain reaction was used to detect the expression of B7-H3 mRNA in EC tissue obtained during preoperative gastroscopy, and its correlation with LNM was analyzed. Radiomics features were extracted from multi-modal magnetic resonance imaging of EC using Pyradiomics in Python. Feature extraction, data dimensionality reduction, and feature selection were performed using XGBoost model and leave-one-out cross-validation. Multivariable logistic regression analysis was used to establish the prediction model, which included radiomics features, LN status from computed tomography (CT) reports, and B7-H3 mRNA expression, represented by a radiomics nomogram. Receiver operating characteristic area under the curve (AUC) and decision curve analysis (DCA) were used to evaluate the predictive performance and clinical application value of the model., Results: The relative expression of B7-H3 mRNA in EC patients with LNM was higher than in those without metastasis, and the difference was statistically significant ( P < 0.05). The AUC value in the receiver operating characteristic (ROC) curve was 0.718 (95%CI: 0.528-0.907), with a sensitivity of 0.733 and specificity of 0.706, indicating good diagnostic performance. The individualized clinical prediction nomogram included radiomics features, LN status from CT reports, and B7-H3 mRNA expression. The ROC curve demonstrated good diagnostic value, with an AUC value of 0.765 (95%CI: 0.598-0.931), sensitivity of 0.800, and specificity of 0.706. DCA indicated the practical value of the radiomics nomogram in clinical practice., Conclusion: This study developed a radiomics nomogram that includes radiomics features, LN status from CT reports, and B7-H3 mRNA expression, enabling convenient preoperative individualized prediction of LNM in EC patients., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

The catalytic bis-allylation of alkynes is an important but challenging protocol to construct all-carbon tetra-substituted alkenes. Particularly, the catalytic unsymmetrical bis-allylation of alkynes remains as an underexplored task to date. We herein report an unprecedented unsymmetrical bis-allylation by simultaneously utilizing electrophilic trifluoromethyl alkene and nucleophilic allylboronate as the allylic reagents. With the aid of robust Ni 0 /NHC catalysis, valuable skipped trienes can be obtained in high regio- and stereo-selectivities under mild conditions. Mechanistic studies indicate that the reaction may proceed through a β-fluorine elimination of a nickelacycle followed by a transmetalation step with allylboronate. The present method exhibits a good tolerance of various functional groups. Besides, the skipped triene products can undergo an array of elaborate transformations, which highlights the potential applications of this strategy., (© 2023 Wiley-VCH GmbH.)

Skeletal reorganization reactions have emerged as an intriguing tool for converting readily available compounds into complicated molecules inaccessible by traditional methods. Herein, we report a unique skeleton-reorganizing coupling reaction of cycloheptatriene and cycloalkenones with amines. In the presence of Rh/acid catalysis, cycloheptatriene can selectively couple with anilines to deliver fused 1,2-dihydroquinoline products. Mechanistic studies indicate that the retro-Mannich type ring-opening and subsequent intramolecular Povarov reaction account for the ring reorganization. Our mechanistic studies also revealed that skeleton-reorganizing amination between anilines and cycloalkenones can be achieved with acid. The synthetic utilization of this skeleton-reorganizing coupling reaction was showcased with a gram-scale reaction, synthetic derivatizations, and the late-stage modification of commercial drugs., (© 2022 Wiley-VCH GmbH.)

Depending on the reactant property and reaction mechanism, one major regioisomer can be favored in a reaction that involves multiple active sites. Herein, an orthogonal regulation of nucleophilic and electrophilic sites in the regiodivergent hydroamination of isoprene with indazoles is demonstrated. Under Pd-hydride catalysis, the 1,2- or 4,3-insertion pathway with respect to the electrophilic sites on isoprene could be controlled by the choice of ligands. In terms of the nucleophilic sites on indazoles, the reaction occurs at either the N 1 - or N 2 -position of indazoles is governed by the acid co-catalysts. Preliminary experimental studies have been performed to rationalize the mechanism and regioselectivity. This study not only contributes a practical tool for selective functionalization of isoprene, but also provides a guide to manipulate the regioselectivity for the N-functionalization of indazoles., (© 2021 Wiley-VCH GmbH.)

In the present paper, based on the fast evaluation technique of near infrared, a method to predict the yield of atmos- pheric and vacuum line was developed, combined with H/CAMS software. Firstly, the near-infrared (NIR) spectroscopy method for rapidly determining the true boiling point of crude oil was developed. With commercially available crude oil spectroscopy da- tabase and experiments test from Guangxi Petrochemical Company, calibration model was established and a topological method was used as the calibration. The model can be employed to predict the true boiling point of crude oil. Secondly, the true boiling point based on NIR rapid assay was converted to the side-cut product yield of atmospheric/vacuum distillation unit by H/CAMS software. The predicted yield and the actual yield of distillation product for naphtha, diesel, wax and residual oil were compared in a 7-month period. The result showed that the NIR rapid crude assay can predict the side-cut product yield accurately. The near infrared analytic method for predicting yield has the advantages of fast analysis, reliable results, and being easy to online operate, and it can provide elementary data for refinery planning optimization and crude oil blending.