Although the type of XHD150B-IO 800mA X-ray machine possesses a damage protection electric circuit for the main thyristors, with the first switch of photographic hand valve pressed, abnormal instant exposure still appears when double (in different phase) or more than three main thyristors are broken through, short-circuited or mis-energized, and consequently the high voltage element or X-ray machine will break down. Therefore the original electric circuit must be improved. Material: A few of leads. Method: We exchange the conjunction sequence of three NO (normal open) contacting points of radiograph high voltage preparing work relay--MAG SW- R with three reverse parallel connection of main thyristors. Conclusion: The normal procedure of radiographic exposure won't be disturbed after the improvement. When whichever one or more than two main thyristors is broken through, short-circuited or mis-energized, the spoilage can be detected instantly and the protection circuit works correspondingly, which guarantees the safety of X-ray machine.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.