OBJECTIVES: To investigate the protective mechanism of quercetin, the core component of Zuo Gui Wan, against Alzheimer's disease through the PI3K/AKT signaling pathway, based on network pharmacology, molecular docking, and cell experi-ments. METHODS: The active components of Zuo Gui Wan were identified by searching TCMSP, PubChem, Swiss Target Prediction, and BATMAN-TCM databases, and their potential targets were predicted. The target information was standardized using Uniprot, and Alzheimer's disease-related target genes were obtained from Drugbank, GeneCards, and OMIM. The intersection of these datasets was used to identify the potential targets of Zuo Gui Wan for treating Alzheimer's disease. Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The protein-protein interaction (PPI) network of potential targets was visualized using Cytoscape 3.10.1 software and the STRING database. The key active compounds and core potential targets for treating Alzheimer's disease with Zuo Gui Wan were identified through calculation. Based on the enrichment analysis results and literature, quercetin and the PI3K/AKT pathway were selected for verification. Molecular docking and binding ability prediction between quercetin and the core target AKT were performed using CB-Dock2, and visualization was conducted with AutoDock and PyMOL software. Finally, Aβ_1-42-induced HT-22 mouse hippocampal neuronal cells were used to construct an Alzheimer's disease cell model. Quercetin, the PI3K inhibitor LY294002, and the activator EGF were used as interventions. The groups were divided as follows: Control, Aβ_1-42, Aβ_1-42+Quercetin 2.5 μM, Aβ_1-42+Quercetin 5 μM, Aβ_1-42+Quercetin 10 μM, Aβ_1-42+EGF, and the PI3K/AKT modulation group: Control, LY294002, LY294002+Quercetin 10 μM, LY294002+EGF. CCK-8 assays were performed to detect cell viability, while JC-1, Calcein AM-PI, and Hoechst staining were used to assess cell apoptosis. Western blotting was employed to detect the expression of relevant target proteins. RESULTS: Network pharmacology and cell experiments collectively demonstrate that the key active ingredient of Zuo Gui Wan, quercetin, targets core proteins such as AKT1 and GSK3β through a network-based approach, significantly enriching the PI3K/AKT pathway. Molecular docking results indicate that quercetin has a strong binding affinity with AKT. Experimental validation in the Aβ_1-42 oligomer-induced HT-22 model reveals that quercetin significantly activates the PI3K/AKT signaling pathway, which is inhibited by Aβ_1-42 oligomers, as well as Bcl-2 protein expression. It also suppresses the expression of Cleaved Caspase 3/Caspase 3, BAX, and Cytochrome C proteins. JC-1, Hoechst 33342, and Calcein AM-PI staining results further show that quercetin can significantly alleviate apoptosis induced by Aβ_1-42 oligomers in HT-22 cells. Treatment with the PI3K inhibitor LY294002 in HT-22 cells leads to reduced cell viability and decreased expression of p-AKT/AKT and Bcl-2 proteins, while increasing the expression of Cleaved Caspase 3/Caspase 3, BAX, and Cytochrome C proteins. Additionally, apoptosis levels increase as observed in JC-1, Hoechst 33342, and Calcein AM-PI staining, all of which can be reversed by quercetin and the PI3K agonist EGF. CONCLUSIONS Quercetin, the key active ingredient of Zuo Gui Wan, exerts its protective effects against Alzheimer's disease by regulating the PI3K/AKT signaling pathway, inhibiting neuronal cell damage and apoptosis.

Objective To evalutate the accuracy of CyberKnife system and measure its relative output factor.Methods The accuracy of target localization of the system was measured with E2E test,film dosimetry,6D-skull tracking mode and fiducial tracking mode.Six kinds of detectors were used to detect the collimators of the system.Results The positioning errors were (0.531 ±0.293) and (0.482±0.297) mm respectively by 6D-skull tracking mode and fiducial tracking mode.The detectors proved the relative output factors of 5-mm collimator were 0.133 ±0.006,0.320±0.010,0.635 ±0.010,0.656±0.009,0.777± 0.013 and 0.680±0.014,and those of 35-mm collimator were 0.983±0.002,0.990±0.002,0.987±0.001,0.992±0.002,0.990± 0.010 and 0.981 ±0.010.Conclusion The total error of CyberKnife system was less than 1 mm.Large collimater has high consistencies between the output factors of the detectors,while there are significant differences between the output factors in case of the collimater with the diameter less than 15 mm.