Objective To analyze the results of acceptance testing of 60 extraoral dental X-ray equipment in Beijing, China from 2021 to 2022, and understand the main types and performance parameters of newly installed extraoral dental X-ray machines in the clinical market of Beijing, as well as the level of installation and trial run of the whole machine by various manufacturers, and to summarize the problems found in acceptance testing for improving equipment testing. Methods Field acceptance testing and evaluation were carried out according to the Specification for Testing of Quality Control in Medical X-Ray Diagnostic Equipment (WS 76—2020). Results The overall qualified rate of 60 extraoral dental X-ray equipment was 98.33%. Under the same condition of the same tube voltage for one dental equipment, the maximum deviation of the tube voltage indicated by the two modes (panorama and skull) is 5.5%, and the maximum difference of the half-value layer of the useful beam is 1.22 mm Al. There is also a certain difference between the exposure time indicating deviation from the panorama and the skull, with a maximum difference of 75.51%. Conclusion Strengthening ex-factory quality control, installing, and debugging of equipment can basically guarantee the performance of newly installed equipment. In the testing process, it is critical to ensure the effective point of measurement of the dose detector located on the central axis of the primary beam.

Objective: To investigate the function and potential mechanism of hepatocellular carcinoma(HCC) cells-derived extracellular nicotinamide phosphoribosyl transferase(eNAMPT) in the angiogenesis of human umbilical vein endothelial cells(HUVEC). Methods: The eNAMPT secretion of HCC cells were stimulated by hypoxia treatment and investigated the angiogenesis of HUVEC was investigated by tube formation assays. Transcriptomic RNA sequencing(RNA-seq) analyses of HUVEC under eNAMPT treatment were used to explore the mechanism of the effect of eNAMPT-insulin receptor(INSR) axis on angiogenesis. Western blot was used to detect the effects of eNAMPT-INSR axis on protein expression of HUVEC cells. qRT-PCR was used to detect the influence of eNAMPT-INSR axis on the expression of HUVEC intracellular related target genes. Results: ELISA and Western blot results showed that the protein level of eNAMPT in the culture supernatant of HCC cells increased significantly after hypoxia stimulation.In vitroangiogenesis assay results showed that eNAMPT significantly increased the nodules number and total length of tubes in HUVEC. The transcriptome sequencing results of HUVEC showed that eNAMPT, as an insulin analogue, participated in the regulation of biological processes such as cell migration and angiogenesis in HUVEC, and might promote angiogenesis by activating insulin-like signaling pathways. Western blot results showed that the eNAMPT-INSR axis affected p-AKT and p-ERK1/2 protein levels in PI3K-AKT and MAPK-ERK1/2 signaling pathways in HUVEC. qRT-PCR results showed that the eNAMPT-INSR axis affected the expression of angiogenesis related target genes MMP2, MMP9 and VEGF in HUVEC. Conclusion eNAMPT secreted by HCC cells promotes angiogenesis by binding INSR to activate the PI3K-AKT and MAPK-ERK1/2 signaling pathways.