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Extracellular vesicles (EVs) are defined as key nanoscale messengers that mediate intercellular communication, demonstrating immense potential in tissue repair and regenerative medicine. As the only organ in mammals capable of complete, cyclical regeneration, deer antlers provide EVs with exceptional regenerative bioactivity. This paper systematically reviews and prospectively discusses the research field of deer antler-derived EVs. We first outline their isolation strategies and characteristic functional subtypes, then focus on elucidating their multi-level molecular mechanisms driving tissue repair: at the cellular level, they directly regulate stem cell proliferation and lineage differentiation; at the microenvironmental level, they effectively remodel the immune ecology of injured areas by reprogramming immune cells and coordinating cytokine networks, thereby creating favorable conditions for regeneration. At the molecular level, they precisely regulate core signaling pathways, including the Wnt/β-catenin, NF-κB, miR-21-5p/STAT3, and TGF-β pathways. Finally, this paper prospectively explores cutting-edge developments in the field, including enhancing vesicle targeting and drug-loading capacity through engineering strategies, constructing controlled-release delivery systems based on smart materials, and developing precision therapies tailored to specific pathological microenvironments. This review aims to elucidate the biomedical potential of deer antler extracellular vesicles as regenerative nanomedicines for promoting tissue repair.

Similitude design plays a vital role in the analysis of vibration and shock problems encountered in large engineering equipment. Similitude design, including dimensional analysis and governing equation method, is founded on the dynamic similitude theory. This study reviews the application of similitude design methods in engineering practice and summarizes the major achievements of the dynamic similitude theory in structural vibration and shock problems in different fields, including marine structures, civil engineering structures, and large power equipment. This study also reviews the dynamic similitude design methods for thin-walled and composite material plates and shells, including the most recent work published by the authors. Structure sensitivity analysis is used to evaluate the scaling factors to attain accurate distorted scaling laws. Finally, this study discusses the existing problems and the potential of the dynamic similitude theory for the analysis of vibration and shock problems of structures.

Southwestern Henan Province in central China contains many down-faulted basins, including the Xixia Basin where the Upper Cretaceous continental sediments are well exposed. The Majiacun Formation is a major dinosaur-bearing stratigraphic unit that occurs in this basin. A new basal hadrosauroid dinosaur, Zhanghenglong yangchengensis gen. et sp. nov., is named based on newly collected specimens from the middle Santonian Majiacun Formation of Zhoujiagou Village, Xixia Basin. Two transitional features between basal hadrosauroids and hadrosaurids are attached to the diagnosis of the new taxon, namely five maxillary foramina consisting of four small scattered ones anteroposteriorly arranged in a row and a large one adjacent to the articular facet for the jugal, and dentary tooth crowns bearing both median and distally offset primary ridges. Zhanghenglong also displays a unique combination of plesiomorphic and derived features of hadrosauroids, and is clearly morphologically transitional between basal hadrosauroids and hadrosaurids. Furthermore, some measurement attributes in osteology are applied to the quantitative analysis of Zhanghenglong. For these attributes, the partition of the dataset on most hadrosauroid species resulting from model-based cluster analysis almost matches taxonomic separation between basal hadrosauroids and hadrosaurids. Data of Zhanghenglong on selected measurement attributes straddle the two combinations of intervals of partitioned datasets respectively related to basal hadrosauroids and hadrosaurids. This condition is similar to mosaic evolution of morphological characters present in the specimens of the taxon. The phylogenetic analysis of Hadrosauroidea recovers a clade composed of Zhanghenglong, Nanyangosaurus, and Hadrosauridae with an unresolved polytomy. Zhanghenglong is probably a relatively derived non-hadrosaurid hadrosauroid, based on the inferences made from the morphological comparisons, quantitative evaluation of measurements, and cladistic analysis. In combination with information on the stratigraphy, phylogeny and biogeography, the material of Zhanghenglong provides direct evidence for the hypothesis that hadrosaurids might have originated in Asia.

A long-span hybrid grid hangar structure and a modeling method for the long-span hybrid grid hangar structure based on the principle of leverage are proposed in this paper. Based on the SAP2000 spatial structure design software, the C# language was used to develop a plug-in to automatically create a long-span hybrid grid structure based on the principle of leverage, which realized the automatic generation by inputting parameters such as the span of the hangar structure, the number of horizontal grids, and the number of vertical grids. The optimization design method of the long-span hybrid grid structure based on particle swarm algorithm is proposed. SAP2000 software is used and the C# language is used to develop the optimization design program of the long-span hybrid grid structure based on the principle of leverage. The optimization design is carried out, and the optimization results show that the program can reduce the thickness of the roof and reduce the vertical displacement at the opening of the hangar roof on the basis of meeting the current specifications.

For the applicability of dynamic similitude models of thin walled structures, such as engine blades, turbine discs, and cylindrical shells, the dynamic similitude design of typical thin walled structures is investigated. The governing equation of typical thin walled structures is firstly unified, which guides to establishing dynamic scaling laws of typical thin walled structures. Based on the governing equation, geometrically complete scaling law of the typical thin walled structure is derived. In order to determine accurate distorted scaling laws of typical thin walled structures, three principles are proposed and theoretically proved by combining the sensitivity analysis and governing equation. Taking the thin walled annular plate as an example, geometrically complete and distorted scaling laws can be obtained based on the principles of determining dynamic scaling laws. Furthermore, the previous five orders’ accurate distorted scaling laws of thin walled annular plates are presented and numerically validated. Finally, the effectiveness of the similitude design method is validated by experimental annular plates.

In the present study, a new method of predicting the dynamic behavior of a variable thickness (VT) cantilever plate by using a thin plate scaled model is proposed. The thin plate model, defined as the model thin (MT) plate, is designed by using the newly proposed similitude design method. The method is derived based on the transfer matrix of both the stepped thickness (ST) plate that is simplified by the VT plate and the thin plate. The thickness of the MT plate is calculated by introducing the equivalent thickness corresponding to each VT plate’s vibration modals, such that a series of accurate distorted scaling laws are provided to predict each corresponding property. Moreover, an algorithm of designing the MT plate is proposed and a design process is summarized in steps. Finally, an example, where the prototype VT plate is made of 42 CrMo and the MT plate is made of NO. 45 steel, is discussed to validate the proposed design method, showing that the MT plate, which is designed by using the proposed method, can accurately predict the dynamic properties of the prototype VT plate, and showing its significance in engineering practice.

A finite element model of the cantilever combined support rotor included two discs established in this paper to predict and explain the nonlinear vibration phenomenon. The model considered local nonlinear support force generated by the combined support and the coupling effects of the rotor with the combined support. The nonlinear factors contained the clearance, the Hertz contact force and the vibration of the rolling bearing and the nonlinear force of the squeeze film damper. The combined support included bearing, squeeze film damper and squirrel cage elastic support. Finally, the high-dimensional partial differential equations with local nonlinearity were derived and solved by Newmark- β combined with Runge–Kutta method. Based on the above theoretical results, the bifurcation phenomenon of vibration response at different positions was analysed and the dynamic response of the rotor system at different positions due to the rotational speed was compared.

This study investigates a method of designing a simplified cylindrical shell model. This model accurately predicts the dynamic characteristics of a prototype cylindrical shell with sealing teeth accurately. The significance of this study is that it provides an acceptable process which guides the design of test models. Firstly, an equivalent cylindrical shell with rectangular rings is designed by combining the energy equation and numerical analysis. Then the transfer matrixes of the stiffened cylindrical shell and the cylindrical shell are employed to calculate the equivalent thickness of the simplified cylindrical shell commonly used in model tests. Further, the equivalent thicknesses are normalized by introducing an average equivalent thickness. The distorted scaling laws and size applicable intervals are investigated to reduce the errors caused by the normalization. Finally, a 42CrMo cylindrical shell with sealing teeth is used as a prototype and a number 45 steel scaled-down cylindrical shell is used as a distorted test model. The accuracy of the prediction is verified by using experimental data, and the results indicate that the distorted model can predict the characteristics of the stiffened cylindrical shell prototype with good accuracy.

Improving the identification accuracy of internal ballistic parameters in the solid rocket motor(SRM) is of great significance in guaranteeing that missiles fulfill their intended operational missions. In practice, the internal ballistic performance is according to the inverse calculation burning area obtained by the measured pressure data of the SRM and the measured burning rate, which still has ascending space for optimization in the prediction accuracy. Accordingly, a genetic algorithm-based method for the identification of internal ballistic parameters and performance prediction for SRMs was proposed. Based on the measured, data of limited test runs, the initial identification of the burning rate coefficient, pressure exponent and propellant density was carried out by GA (Genetic Algorithm). The model was updated on the basis of the inverse calculation burning area obtained by identification results. Then the secondary identification was carried out to modify the key parameters. The Φ50mm laboratory-scale test SRM was analyzed as an example. The internal ballistic performance in the SRM was predicted. The calculation results show that the prediction results obtained by the method are in high agreement with the measured pressure data, which verifies the effectiveness of the method in improving the prediction accuracy of the internal ballistic performance.

This study presents a novel temperature control strategy for Additive Manufacturing (AM) of thermosetting carbon fiber composites, integrating Dynamic Matrix Control (DMC), Improved Eagle Perching Optimization (IEPO), and a Proportional-Integral-Derivative (PID) controller, termed the DMC-IEPO-PID algorithm. This approach addresses traditional PID controller limitations like sluggish response, overshoot, and poor adaptability in complex manufacturing. By combining the simplicity of PID, adaptability of IEPO, and predictive accuracy of DMC, the algorithm improves temperature regulation in AM. Simulations and experiments at 250°C, 300°C, and 350°C showed superior performance in reducing fluctuations, stabilization time, and improving accuracy. The findings confirm the DMC-IEPO-PID’s effectiveness in handling nonlinearities and time-varying characteristics, optimizing AM processes for thermosetting composites.