The mediating role of depression symptoms in childhood abuse and cyberbullying among college students / 中华疾病控制杂志

Objective Analyze the correlation of depression between the childhood abuse behavior and adulthood cyberbullying behavior, so as to discuss and provide evidences for preventing the cyberbullying behavior of college students. Methods A total of 4 040 college students were surveyed after multistage stratified cluster random sampling from 6 universities in Shanxi Province of China by using childhood trauma questionnaire, self-rating depression scale and cyberbullying scale. Results In the three dimensions of cyberbullying, cyber-verbal bullying behavior, identity concealing behavior and cyber-forgery fraud behavior, male students and only child students scored higher than that of female students and non-only child students (all P<0.001). There was a positive correlation between childhood abuse, adult depression and cyberbullying (all P<0.001). The mediation effect results showed that depression symptoms of college students were mediating between childhood abuse experience and cyberbullying behavior (the mediation effect result was 0.090, P<0.001), the mediation effect contributed 12.16% to the total effect, the mediation model fitting index were 2/df=39.96，RMSEA=0.101，CFI=0.948，TLI=0.924，SRMR=0.043. Conclusions Childhood abuse experience and adulthood depression are closely related to the implementation of cyberbullying behavior in college, and depression plays part of mediating role in predicting the implementation of cyberbullying behavior in college students who has childhood abuse experience.

Measurement on bone density of children's mandible by quantitative computed tomography / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the change of bone density of children's mandible measured by quantitative computed tomography (QCT).</p><p><b>METHODS</b>71 children aged between 10-16 years were measured by QCT in left mandible angle, middle of mandible and right mandible angle. The differences were analyzed according to the age and sex respectively.</p><p><b>RESULTS</b>The density of mandible of left mandible angle, middle of mandible, right mandible angle were 44.29, 89.70, 54.31 mg/dL in the 10-12 ages group, and 63.85, 122.47, 70.23 mg/dL in the 13-16 ages group.</p><p><b>CONCLUSION</b>Male youngster's mandible density was increased with the age between 10-12 and 13-16 ages. There were significant differences between left mandible angle, middle of mandible and right mandible angle. There were significant differences of mandible density between male and female.</p>