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A virtual synchronous generator (VSG) has a good adaptability to the weak grid but its grid-connected active power (GCAP) has the problem of a slow dynamic response under the active power command step. An optimization strategy of the GCAP dynamic response for the VSG based on the virtual negative impedance combined with the active power transient damping control algorithm is proposed in this paper. The optimization strategy first uses the virtual negative impedance control method to reduce the VSG equivalent output impedance and the GCAP dynamic response time of the VSG. Then, the transient damping as well as the inhibition ability of the GCAP dynamic oscillation for the VSG are enhanced by the active power transient damping control algorithm. The Matlab/Simulink simulation software is used to study the GCAP dynamic response performances of the VSG in the condition of the active power command step, and the experimental test platform of a VSG grid-connected system is established. The simulation and experimental results jointly verify the feasibility and superiority of the proposed strategy in improving the GCAP dynamic response characteristics of the VSG under a weak grid.

The rapid and accurate identification of sugarcane stem nodes in the complex natural environment is essential for the development of intelligent sugarcane harvesters. However, traditional sugarcane stem node recognition has been mainly based on image processing and recognition technology, where the recognition accuracy is low in a complex natural environment. In this paper, an object detection algorithm based on deep learning was proposed for sugarcane stem node recognition in a complex natural environment, and the robustness and generalisation ability of the algorithm were improved by the dataset expansion method to simulate different illumination conditions. The impact of the data expansion and lighting condition in different time periods on the results of sugarcane stem nodes detection was discussed, and the superiority of YOLO v4, which performed best in the experiment, was verified by comparing it with four different deep learning algorithms, namely Faster R-CNN, SSD300, RetinaNet and YOLO v3. The comparison results showed that the AP (average precision) of the sugarcane stem nodes detected by YOLO v4 was 95.17%, which was higher than that of the other four algorithms (78.87%, 88.98%, 90.88% and 92.69%, respectively). Meanwhile, the detection speed of the YOLO v4 method was 69 f/s and exceeded the requirement of a real-time detection speed of 30 f/s. The research shows that it is a feasible method for real-time detection of sugarcane stem nodes in a complex natural environment. This research provides visual technical support for the development of intelligent sugarcane harvesters.

In wind turbine systems, bolted connections are frequently subjected to gravitational and centrifugal loads transmitted by the blades during operation. This can lead to the attenuation of bolt preloading, resulting in bolt loosening or uneven loading, which in turn affects the service life of the generator unit. Therefore, the study of bolt preloading variations is crucial. However, there are numerous factors influencing bolt preloading, and the existing techniques struggle to precisely assess bolt preloading. This paper proposed a bolt preloading evaluation technique based on the hammer modal method. Focusing on the 42CrMo4 bolted connection of a pitch bearing, a test platform for bolt preloading assessment is constructed. Hammer modal tests are conducted under various preloading forces. By combining finite element modal analysis, the correspondence between preloading changes and the bending frequencies and modes of the bolted connection is obtained. The research illustrated that with changes in bolt preloading, variations occur in coherence, phase, and natural frequencies of frequency response functions. The fundamental correlation between bolt preloading and the second-order bending frequency can be utilized to assess changes in preloading. Furthermore, the applicability of this method has been validated, offering a reference for evaluating bolt preloading.

Our previous study demonstrated the beneficial effects of exosomes secreted by cardiac mesenchymal stem cells (C-MSC-Exo) in protecting acute ischemic myocardium from reperfusion injury. Here, we investigated the effect of exosomes from C-MSC on angiogenesis in ischemic myocardium. We intramyocardially injected C-MSC-Exo or PBS into the infarct border zone after induction of acute mouse myocardial infarction (MI). We observed that hearts treated with C-MSC-Exo exhibit improved cardiac function compared to control hearts treated with PBS at one month after MI. Capillary density and Ki67-postive cells were significantly higher following treatment with C-MSC-Exo as compared with PBS. Moreover, C-MSC-Exo treatment increased cardiomyocyte proliferation in infarcted hearts. In conclusion, intramyocardial delivery of C-MSC-Exo after myocardial infarction enhances cardiac angiogenesis, promotes cardiomyocyte proliferation, and preserves heart function. C-MSC-Exo constitute a novel form of cell-free therapy for cardiac repair.

Background Studies in populations with or without cardiovascular disease have shown that very high HDL-C levels are associated with an increased risk of cardiovascular events. However, the exact relationship between HDL-C levels and long-term prognosis remains unknown in patients with myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI). Methods This was a post hoc secondary analysis of long-term follow-up results in patients undergoing PCI open-label, observational cohort study. Patients with MI who had undergone PCI were enrolled. Restricted cubic spline (RCS) analysis and logistic regression analysis were performed to assess the relationship between HDL-C levels and the risk of cardiovascular events. Results A total of 1934 patients with MI undergoing PCI were enrolled in our analysis and our population was divided in 3 groups according to the HDL-C plasma levels: HDL-C < 40 mg/dL (low HDL-C); HDL-C between 40 and 80 mg/ dL (medium HDL-C); and HDL-C > 80 mg/dL (high HDL-C). RCS analysis showed a nonlinear U-shaped association between HDL-C levels and major adverse cardiac and cerebrovascular events (MACCE) in patients with NSTEMI with adjusted variables. After adjusting for potential confounders, the follow-up analysis indicated that high risk group had elevated occurrence of MACCE than low risk group (HDL-C 35 and 55 mg/dL) (OR:1.645, P = 0.006). Conclusions Our analysis demonstrated that there is a U-shaped association between HDL-C and MACCE in patients with NSTEMI undergoing PCI.

Chimeric antigen receptor‐engineered natural killer T (CAR‐NKT) cell therapy represents a promising and innovative strategy in cancer immunotherapy, but is limited by acute toxicity and adverse effects, restricting broader clinical application despite durable responses. In this study, a novel nanobody targeting TM4SF1 is developed, which replaced the conventional single‐chain variable fragment (scFv) in the design of CARTM4SF1‐NKT cells. Moreover, CARTM4SF1‐extracellular vesicles (EVs) therapy as an optimized alternative to direct CAR‐NKT cell administration is introduced. Compared with conventional CARTM4SF1 engineered cells, CARTM4SF1‐EVs demonstrated superior antitumor efficacy while significantly reducing toxicity. This findings revealed that CARTM4SF1‐EVs selectively targeted TM4SF1‐expressing tumor cells in both in vitro and in vivo models. In hepatocellular carcinoma (HCC) mouse models, CARTM4SF1‐EVs induced immunogenic cell death (ICD) and effectively suppressed tumor growth and metastasis. The therapeutic efficacy of CARTM4SF1‐EVs is primarily attributed to their ability to remodel the immunosuppressive tumor microenvironment (TME), notably by enhancing CD8⁺ T cell activity and eliciting robust antitumor immune responses. Furthermore, CARTM4SF1‐EVs synergized with Immune Checkpoint Blockade (ICB) therapy, leading to durable antitumor immune memory. Collectively, these findings establish CARTM4SF1‐EVs therapy as a safe and effective strategy for targeted cancer immunotherapy, underscoring its potential for clinical application. TM4SF1‐nanobody engineered CAR‐natural killer T–derived extracellular vesicles (CARTM4SF1‐EVs) provide a cell‐free alternative to CAR‐NKT therapy, achieving potent, targeted antitumor activity with reduced toxicity. CARTM4SF1‐EVs induce immunogenic cell death, remodel the tumor microenvironment, and enhance CD8⁺ T‐cell antitumor immunity. They further synergize with immune checkpoint blockade, providing a safe and effective strategy for cancer immunotherapy.

Large polycyclic aromatic hydrocarbon (PAH) imides are promising candidates for optoelectronic applications in view of their narrow optical gaps and/or excited state charge transfer character. Diels–Alder (D–A) reactions of PAHs at bay regions can enable simultaneous extension of the aromatic structure and introduction of the imide moieties, but the actual use of this strategy has been limited. Herein, we demonstrate the D–A cycloaddition of dibenzo[ hi , st ]ovalene, one of the largest PAHs functioning as bisdiene, with maleimides to afford circumpyrene tetracarboxydiimides. Notably, efforts to optimize the yield of di-adduct revealed that the fully aromatized mono-adduct is inert toward further D–A reaction, and density functional theory (DFT) calculations instead indicated a partially dehydrogenated mono-adduct as the key intermediate enabling the second cycloaddition. The resulting product represents a rare example of PAH diimide featuring an acceptor-donor-acceptor type structure. Detailed spectroscopic and theoretical studies, including transient absorption and two-dimensional electronic spectroscopy, revealed the emergence of a bright intramolecular charge transfer state that could be directly excited to demonstrate distinct photophysical dynamics. These findings provide deep mechanistic insights into the D–A reactivity of large PAHs and underscores the potential of such PAH imides for advanced optoelectronic and photonic applications. Although Diels–Alder (D–A) reactions of polycyclic aromatic hydrocarbons (PAHs) at bay regions can enable the introduction of imide moieties to form large PAH imides — which are promising candidates for optoelectronic applications —the use of this synthetic strategy has remained limited. Here, the authors demonstrate the D–A cycloaddition of dibenzo[ hi , st ]ovalene with maleimides to produce circumpyrene tetracarboxydiimides featuring an acceptor-donor-acceptor-type structure, exhibiting bright intramolecular charge transfer character relevant for optoelectronic devices.

Dendrobium officinale (DEN) has long been a medicinal and functional food resource in China. This study employed network pharmacology to reveal its mechanisms of action in the treatment of cardiovascular diseases (CVDs), including myocardial infarction (MI) and hemorrhagic cerebrovascular diseases (HCD). The active ingredients of DEN were identified by liquid chromatography‑tandem mass spectrometry (LC‑MS/MS) and screened using the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP). Functional enrichment analysis and gene set enrichment analysis were performed to identify enriched pathways, followed by molecular docking, single-cell RNA sequencing (scRNA-seq) analysis, and experimental verification. Two active ingredients of DEN, quercetin and wogonin, were identified, corresponding to 100 and 25 potential targets, respectively. A total of 390 and 363 DEGs were screened between MI and HCD samples, and were intersected with the potential targets of quercetin and wogonin. Functional enrichment analysis of targets associated with the two core targets, matrix metalloproteinase-9 (MMP9) and glycogen phosphorylase L (PYGL), revealed enrichment in pathways related to the cellular matrix and neutrophil degranulation. GSEA showed that samples stratified by high or low expression of MMP9 and PYGL were predominantly enriched in inflammation-related pathways. Quercetin showed strong binding to MMP9. scRNA-seq data confirmed the expression of PYGL and MMP9 at single-cell resolution. Furthermore, silencing MMP9 in modeled AC16 cells attenuated injury and promoted proliferation. This study showed that the active compounds of DEN may exert therapeutic effects on MI and HCD through multiple mechanisms, thereby supporting the efficacy of DEN in treating CVDs.

Dredged soil treatment and reuse remain major economic and environmental challenges in geotechnical and highway engineering. Cement-based stabilization can effectively improve the engineering properties of dredged soil, but its large-scale use is associated with high material costs, energy consumption, and carbon emissions. In this study, a solid-waste-based binder composed of calcium carbide slag (CS), ground granulated blast-furnace slag (GGBS), and fly ash (FA) was developed as a potential cement alternative for stabilizing organic-rich dredged soil in road applications. Based on mortar-performance screening, a CS:GGBS:FA mass ratio of 0.25:0.50:0.25 was selected, and the road performance and durability of the resulting CS-GGBS-FA (CGF)-stabilized soil were systematically evaluated. Laboratory tests, including California bearing ratio (CBR), dynamic resilient modulus (MR), wet–dry (W–D) cycling, and freeze–thaw (F−T) cycling, were conducted, with cement-stabilized soil used as a reference. The results showed that the CBR and MR of the CGF-stabilized soil increased significantly with binder content and curing time, meeting the requirements for subgrade and subbase applications under different highway classes. Compared with cement-stabilized soil, the CGF-stabilized soil showed slightly lower CBR and MR values at the same binder content but exhibited favorable strength retention and mass stability during W–D and F–T cycling. Overall, a CGF content of at least 8% provided sufficient strength, stiffness, and durability for road use.

In order to improve the steering characteristics, roll characteristics, and lateral characteristics of heavy commercial vehicles, a multiobjective handling stability comprehensive score optimization model (MHSCS optimization model) was proposed in this study. In this study, the main factors affecting the steering characteristics, roll characteristics, and lateral characteristics are determined by combining the road test method and ADAMS software simulation analysis method. Based on the above road tests and ADAMS software simulation analysis, the MHSCS optimization model was proposed with “understeering degree,” “vehicle roll angle”, and “rearward amplification (RWA)” as evaluation indexes, and the response surface method combined with genetic algorithm was used to carry out multiobjective optimization of heavy commercial vehicle. ADAMS simulation results show that the comprehensive improvement degree of steering characteristics, roll characteristics, and lateral characteristics of a heavy commercial vehicle after optimization is 15.26%. Finally, the field road test results show that the scoring error between the comprehensive scoring optimization model and the real vehicle test was controlled at 0.4%, which proves the accuracy of the optimization model established in this study and effectively improves the handling stability of heavy commercial vehicles.