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Application of electromagnetic interference-bp technology in mechanical noise control of small DC electrodes

Cao Hui, Zhang Xiaoyan

Diagnostyka

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2025

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Vol. 26, No. 3

art. no. 2025306

EN

With the widespread use of miniaturized electronic equipment in daily life, the problem of electromagnetic interference has become increasingly prominent, especially in precision instruments and communication equipment. To effectively reduce the causes of mechanical noise generated by small DC electrodes during operation and the electromagnetic interference effects on surrounding equipment, a mechanical noise control method that combines piezoelectric impedance technology and back-propagation neural networks is proposed. In the process, small DC motor electrodes were used as the research object, and the sources of mechanical noise generated by the motor were analyzed. At the same time, different analysis software was used to simulate and model the stator and rotor of the motor. The results show that when different algorithms are run on the training set and test set, when the amount of data increases to 560 and 1120 respectively, the method constructed in the experiment has the maximum fitness value, with values as high as 98.98% and 97.86%. When the training set is run, when the running time increases to 0.894s, the accuracy of the method constructed in the experiment to control mechanical noise reaches 91.68%. The application effect shows that when the material of the stator shell is steel, the occurrence of the maximum natural frequency of the stator is affected by the elastic modulus, which is far greater than the influence of the material density. The experiment provides new ideas and methods for noise and electromagnetic interference control of small DC electrodes.

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STAFGCN: a spatial-temporal attention-based fusion graph convolution network for pedestrian trajectory prediction

Lui Guihong, Pan Chenying, Zhang Xiaoyan, Leng Qiangkui

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2025

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Vol. 73, nr 1

art. no. e151960

EN

Pedestrian trajectory prediction provides crucial data support for the development of smart cities. Existing pedestrian trajectory prediction methods often overlook the different types of pedestrian interactions and the micro-level spatial-temporal relationships when handling the interaction information in spatial and temporal dimensions. The model employs a spatial-temporal attention-based fusion graph convolutional framework to predict future pedestrian trajectories. For the different types of local and global relationships between pedestrians, it first employs spatial-temporal attention mechanisms to capture dependencies in pedestrian sequence data, obtaining the social interactions of pedestrians in spatial contexts and the movement trends of pedestrians over time. Subsequently, a fusion graph convolutional module merges the temporal weight matrix and the spatial weight matrix into a spatial-temporal fusion feature map. Finally, a decoder section utilizes time-stacked convolutional neural networks to predict future trajectories. The final validation on the ETH and UCY datasets yielded experimental results with an average displacement error (ADE) of 0.34 and an final displacement error (FDE) of 0.55. The visualization results further demonstrated the rationality of the model.

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Rapid comparison of antitumor chemical constituents and mechanisms between Dendrobium nobile and Dendrobium officinale by UPLC-IT-TOF, network pharmacology and experimental verification

Liu Jie, Li Zhaoyang, Zeng Meiling, Liang Yan, Liang Bing, Ge Qiuping, Zhang Xiaoyan, Zhang Shilin, Zhou Wei

Acta Chromatographica

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2023

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Vol. 35, no. 2

123--138

EN

Dendrobium nobile and Dendrobium officinale as the main varieties of traditional Chinese medicine Dendrobium are widely used in clinic. The study aimed to systematically explore chemical constituents and their antitumor effect of D. nobile and D. officinale by ultra-performance liquid chromatography coupled with ion trap time-of-flight mass spectrometry (UPLC-IT-TOF), network pharmacology and cancer cell experiments. D. nobile extract and D. officinale extract could significantly inhibit the proliferation of human lung cancer A549 cells, human liver cancer HepG2 cells and human breast cancer MCF-7 cells in the dose-dependent manner (P < 0.05), the antitumor effect of D. officinale extract was stronger than that of D. nobile extract at the same drug concentration. A total of 40 chemical constituents of D. nobile and D. officinale including phenanthrenes, bibenzyls and other types of compounds had been identified by UPLC-IT-TOF, LCMSsolution and MetID software according to retention times, accurate mass, MSⁿ fragmentation, reference compounds and natural product databases. Phenanthrenes with good antitumor activity were mainly present in D. nobile, bibenzyls were the main compounds of D. officinale. Integrated networks of Herb-Compounds-Targets-Cancer revealed that gigantol, moscatilin, tristin, moscatin and densiflorol B were regarded as key antitumor compounds of D. nobile and D. officinale, D. nobile and D. officinale shared 7 targets accounting for 70% of the antitumor core targets, more than half of their antitumor KEGG pathways were similar. The results of molecular docking and western blotting experiments indicated that the antitumor mechanisms of D. nobile and D. officinale may be through inhibiting PI3K-Akt and HIF-1α signaling pathways.

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CF–PK–PD analysis of natural hemostatic compounds from Toddalia asiatica (Linn) Lam root bark in rats

Zhang Xiaoyan, Liu Jie, Sun Wenbo, Shen Xiangchun, Gong Xiaojian, Wang Cong, Liang Yan, Zhou Wei

Acta Chromatographica

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2021

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Vol. 33, no. 3

261--269

EN

Natural hemostatic compounds from Toddalia asiatica (Linn) Lam (T. asiatica) root bark had been investigated by a novel strategy, chemical fingerprint–pharmacokinetic–pharmacodynamic (CF–PK–PD) for the first time in this study. The extract sample of T. asiatica root bark was subdivided into petroleum ether (PE), ethyl acetate (EA) and n-butanol (n-B) sample by reagent extraction, EA sample showed significant hemostatic activity using prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB) as evaluation indexes from rat plasma of PK experiment in hemorrhagic rat model. CF analysis was adopted to assist us to discover six natural compounds from T. asiatica root bark in actual rat plasma after sample treatment by Ultra Performance Liquid Chromatography-Electrospray Ionization (UPLC-ESI) MS, there were only lomatin and 5-methoxy-8-hydroxy psoralen showing significant hemostatic effect (P < 0.05) mainly through endogenous coagulation pathway and fibrinolytic system. In PK–PD study, six compounds in EA sample exhibited relatively rapid absorption and slow elimination characteristics. The mean Tmax and t1/2β of isopimpinellin and pimpinellin were 1.74 and 0.59 h, 5.31 and 6.89 h in rats. On the basis of Sigmoid–Emax model, PK–PD related curves of FIB in hemorrhagic rat model after treatment of T. asiatica root bark were obtained. Predicted Emax, EC50 and ke0 of FIB under isopimpinellin were 4.87 mg/mL, 1.39 μg/mL and 0.81 1/h; predicted Emax, EC50 and ke0 of FIB under pimpinellin were 4.29 mg/mL, 2.47 μg/mL and 0.77 1/h. In conclusion, hemostatic compounds from T. asiatica root bark had been materialized, there were lomatin, isopimpinellin, pimpinellin and 5-methoxy-8-hydroxy psoralen at least as its main active substances through coagulation pathways and fibrinolytic system. CF–PK–PD method as a promising method was worthy of follow-up opening, application in pharmaceutical research.

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Antitumor chemical constituents of Toddalia asiatica (Linn) Lam root bark and its rational alternative medicinal parts by multivariate statistical analysis

Luo Cairong, Liu Jie, Liang Yan, Shen Xiangchun, Zhang Xiaoyan, Zhou Wei

Acta Chromatographica

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2021

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Vol. 33, no. 2

153--161

EN

Toddalia asiatica (Linn) Lam (T. asiatica) as a traditional Miao medicine was investigated to find rational alternative medicinal parts for T. asiatica root bark and its antitumor chemical constituents by quantitative pharmacognostic microscopy, high performance liquid chromatography (HPLC) fingerprint and multivariate statistical analysis. A bivariate correlation analysis method based on microscopic characteristics and content of chemical constituents was established for the first time, there were some regular discoveries between powder microscopic characteristics and common chromatographic peaks of T. asiatica through quantitative pharmacognostic microscopy, cork cells, calcium oxalate square crystal, brown clump, starch granule and phloem fiber, as powder microscopic characteristics may be placed where the main chemical constitutes were enriched. Scores plot of principal component analysis (PCA) and dendrogram of hierarchical clustering analysis (HCA) showed that 18 T. asiatica samples were distinguished correctly, clustered clearly into two main groups as follows: S01∼S03 (root bark) and S07∼S09 (stem bark) in cluster 1, S04∼S06 and S10∼S18 in cluster 2. Nineteen common peaks were obtained in HPLC fingerprint of T. asiatica, loadings plot of PCA indicated seven compounds played important roles in different part of samples (P10 > P08 > P07 > P14 > P16 > P17 > P19), peaks 04, 06, 07, 08, 10 were identified as hesperidin, 4-methoxycinnamic acid, toddalolactone, isopimpinlline and pimpinellin. MTT assay was used to determine the inhibitory activity of different medicinal parts of T. asiatica on human breast cancer MCF-7 cells, all parts of T. asiatica had different inhibitory effects on MCF-7 cell lines, root and stem barks of T. asiatica showed the best inhibitory activity. The relationship between chemical constituents and the inhibitions on MCF-7 cell had been established, significant antitumor constituents of T. asiatica were identified by correlation analysis, the order of the antitumor effect of the main compounds was P07 (toddalolactone) > P16 > P06 (4-methoxycinnamic acid), P11 > P18 > P10 (pimpinellin) > P08 (isopimpinellin) > P01 > P19 > P14 > P04 (hesperidin) > P17, which were antitumor chemical constituents of T. asiatica root bark. T. asiatica stem bark was the most rational alternative medicinal part for T. asiatica root bark.