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Abnormal wear of stitch wires due to interference poses a serious threat to railway safety. To avoid this scenario, the concept of the dynamic envelope of the stitch wire was proposed, accompanied by an interference check method. A multi-node beam model of the stitch wire was established using the finite element method, employed to simulate the pantograph and catenary system, and validated by field test. The dynamic behaviour of the stitch wire was studied, and the concept of dynamic envelope was introduced. Moreover, factors affecting this envelope were analysed, and an interference check method was proposed. Results demonstrate that, the vibration of the stitch wire mainly occurs in the vertical direction and intensifies with increasing speed. Its vertical vibration increases from 70 mm to 137 mm as the train speed goes from 300 km/h to 400 km/h. Cantilever assembly errors and dropper installation issues are the main causes for the abnormal wear of stitch wires. A 100 mm assembly error reduces the clearance from 67 mm to 14 mm, while a 2 m dropper installation error eliminates the clearance entirely. This study provides valuable insights for enhancing the safety of catenary system. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Cone Beam Computed Tomography (CBCT) was used to observe and describe the distribution of canalis sinuosus (CS) in the Chinese population and the location of CS in the maxillary alveolar bone, so as to help oral surgeons evaluate the intraoperative risk and prognosis before maxillary surgery and reduce the complications caused by the injury of this structure in anterior surgery. PATIENTS AND METHODS: CBCT images of 600 patients admitted from 2021 to 2022 were collected to observe the anatomical structure of CS in the maxillary region. The following parameters were recorded: age, sex, number of CS, left and right distribution of CS, CS diameter, and location. Statistical analysis was performed on all of the collected data. RESULTS: The discovery rate of CS in this study was 59.75%, and it is commonly found in the lateral incisor area (64.82%). No significant difference can be found in the presence and number of CS in different gender and age groups (p>0.05). CONCLUSIONS: The use of high-resolution CBCT before implantation is of irreplaceable significance in the diagnosis and analysis of CS, which is conducive to reducing implantation complications and failure rate. The incidence of CS was independent of age or sex, while the location of CS was statistically significant. [ABSTRACT FROM AUTHOR]

Objective: To explore the incidence of sudden deafness accompanied with tinnitus, the selection of examination protocols and treatment, and to provide reference for the establishment of new guidelines for sudden deafness. Methods: CiteSpace software was used for analysis and data mining to analyze and summarize the computer-retrieved articles on diagnostic examination and treatment of sudden deafness accompanied with tinnitus collected from CNIC, Wanfang and Web of Science databases from 2011 to 2021. Results: A total of 207 randomized controlled studies were retrieved in this study, including 121 in Chinese and 86 in English. Finally, 74 Chinese literatures and 16 English literatures were included. Among the 74 valid Chinese literatures, 64 (86.5%) were accompanied with tinnitus, 58 (78.4%) with dizziness/vertigo, 25 (33.8%) with aural fullness, 10 (13.5%) with headache, 4 (5.4%) with insomnia, 4 (5.4%) with a mixture of dizziness and tinnitus, and 2 (2.7%) with vomiting. Among the 16 English literatures, 15 (93.8%) were accompanied with tinnitus, 12 (75.0%) with vertigo, 1 (6.3%) with aural fullness, and 1 (6.3%) with a mixture of various symptoms. Among the 64 Chinese articles mentioning tinnitus, only 9 mentioned tinnitus matching tests, and 1 mentioned that the treatment for tinnitus accompanying symptoms was sound therapy and psychological counseling. The incidence rates of tinnitus accompanying four different types of sudden deafness, from low to high, are as follows: low-to-mid frequency, 82.4%; mid-to-high frequency, 90.7%; complete deafness, 92.4%; and flat type, 92.8%. Conclusion: Tinnitus is the most common accompanying symptom of sudden deafness, and tinnitus matching test is an effective evaluation method. When establishing a scientific, comprehensive, and systematic diagnosis and treatment system or guidelines for sudden deafness, attention should be paid to the diagnosis and treatment of tinnitus symptoms and their adverse psychological reactions, in order to reduce the incidence of tinnitus patients in the later stage of recovery from sudden deafness.