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Conservative treatment and surgical treatment are both effective procedures for treating type II odontoid fractures in the elderly. Compared with surgical treatment, there is no significant difference in mortality; With respect to non-union numbers, conservative treatment numbers are higher than surgical treatment. Due to the poor quality of the evidence currently available, high quality RCTs are required. Level of evidence Level II: low-powered prospective randomized trial meta-analysis.

Recently, with large-scale use of natural gas and massive constructions of gas pipelines, more and more public concern is focused on pipeline leakage. The leakage caused by holes on gas pipelines generates economic losses to gas companies and causes risks to the environment and sometimes accidents. In order to detect and locate pipeline rupture immediately, the leakage detection method plays a key role in the overall integrity management in the pipeline system. One of the most important applications of transient simulation is dynamic leakage detection. A leakage detection model and the solution were proposed based on the three conservation laws in hydromechanics and the state equation, which includes transient simulation model and volume balance model. Dynamic parameters involved in the model such as pressure, flow and temperature can be acquired through SCADA (Supervisory Control and Data Acquisition) system. By analyzing the factors influencing leakage position, we came to a conclusion that leakage and outlet pressure are more important parameters compared to the coefficient of frictional resistance and pipeline diameter. The more leakage increases, the closer leakage point approaches pipeline outlet. Leakage location is closer to outlet when pipeline outlet pressure becomes bigger. Experiments were also carried out according to leakage percentage.

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