Objective: To explore the hot issues and developing trend of the research of campus bulling,and to provide a reference for the research on campus bullying. Methods: The power of research, high-impact authors, highly cited journals, high-frequency keywords, and burst terms related to school bullying from the Web of Science database were analyzed using CiteSpace software. The data collection time was May 9, 2018. Results: A total of 3 561 literature data were obtained. The results showed that the country with the highest number of publications was the United States; England had the highest centrality and was in a critical position in the research. The University of Turku in Finland was the core research institution. Salmivalli C was the author of the highest publication, Olweus D was the most frequent cited author. The high-impact journal was Aggressive Behavior. In terms of high-frequency keywords, the core vocabulary such as bully, adolescence, and victim were listed. Middle school students were the most frequently studied; in the form of bullying, the frequency of violence, aggression, and cyberbully was more common; depression, mental health and health appeared more frequently in terms of bullying outcomes. Mutant words including school children, bullying, victimization, relational aggression were more common. Conclusion The research hotspots on campus bullying during the past decade include violence, gender, social support, and mental health. Bullying among college students will be a hot research topic in the future. Continued efforts should be carried out in the field of campus bullying in China.

Objective:To analyze the biomechanical characteristics of bilateral lumbo-iliac fixation by finite element analysis after digital optimization of a safe screw pathway.Methods:Firstly, a healthy adult male volunteer was recruited for this study who underwent CT scanning of the lumbus and pelvis, with a slice thickness of 0.625 mm.The original data were imported into Mimics 16.0 software for 3D lumbar and pelvic reconstruction.At the same time, a geometric screw pathway and a free screw pathway were generated in the pedicles of L4 and L5 and ilium.Secondly, all 3D models were imported into Ansys 12 software to assemble a finite element model.The displacements and von Misses stress distribution were measured in the conditions of forward bending, backward extending, lateral bending to the left and right, and left and right rotations in the models of 2 kinds of pathway after gravity axial load of 500 N was applied.Results:The models of 2 different pathways were similar in comprehensive displacement and stress in the conditions of forward bending, lateral bending and backward extending, and in the maximum stress of the screw in the conditions of forward bending and lateral bending.However, the comprehensive displacement and stress in the condition of rotation and the stress of the screw in the conditions of backward extending and rotating in the model of geometric screw pathway were obviously smaller than those in the model of free screw pathway.The maximum pelvic stress was on the screw surface between 190 and 260 MPa, concentrated on the bending area of the 2 screws connecting the sacrum and vertebral body.The lumbar-iliac fixation model showed high com-pressive stiffness.The maximum von Misses stress appeared in the L4-L5 pedicle screw on the longitudinal rod.Under rotational loading, the upper longitudinal rod connecting the L4-L5 pedicle screw and the iliac bone screw bore the maximum stress.Conclusions:Our finite element analysis shows that double verte-bral bodies and long screw fixation are effective ways of iliolumbar fixation.The geometric screw path optimized by digital analysis exhibits better fatigue resistance, rotation resistance and overall stability.Internal lum-bo-iliac fixation can effectively share the stress of vertebral bodies.

Based on the national policies, regulations and documents on residency training, this paper sorts out the historical evolution of the standardized residency training system in China, and divides its development into four stages: preliminary exploration, local pilot, national trials, and implementation. It also puts forward some practical thoughts on its development law and future trend, such aspects as that the system reform follows the top-down administrative order and indicative plan, the system pays attention to the gradual implementation on the basis of summing up practical experience, and the system needs continuous implementation and improvement from the overall perspective.