Objective: To investigate the relationship of obsessive beliefs and obsessive-compulsive symptoms in medical students and to provide evidence for prevention and intervention of obsessive-compulsive symptoms in medical students. Methods: Medical students were enrolled from a medical college in Hangzhou and were selected among 3 to 6 classes from Grade One to Grade Four using stratified cluster sampling method. The students were assessed with Obsessive Beliefs Scale-44 （OBD-44） and Obsessive Compulsive Scale Revised （OCD-R）. Linear regression model was conducted to analyze the association between obsessive beliefs and obsessive-compulsive symptoms in medical students. Results: As 592 medical students were surveyed and 544 responses were valid, the response rate was 91.89%. The median score of OCD-R of medical students was 15,and 28.86 of them had obsessive-compulsive symptoms. Concerning OBD-44, the total score of medical students was 154.11±36.05, the scores of responsibility/threat, perfectionism/certainty and importance/control of thoughts were 61.12±14.53, 58.68±14.31 and 32.90±10.76, respectively. The Linear regression analysis demonstrated that gender could predict checking,washing,obsessing and neutralizing; responsibility/threat estimate predicted hoarding and obsessing ;perfectionism/certainty was the most significant predictor of checking,ordering,washing, neutralizing;and importance/control of thoughts predicted hoarding,checking,ordering,washing and obsessing（all P<0.05）. Conclusion Gender, importance/control of thoughts and perfectionism/certainty have significant impact over most of obsessive-compulsive symptoms in medical students.

Objective To explore the feasibility of individual identification based on the 2D-3D face image superimposition in Han individuals.Methods The 2D video surveillance images(including front,left and right side)and high-precision 3D face models of 10 Han individuals were collected,and Autodesk 3ds Max 2018 software was used to perform perspective matching on the 3D face models,and superimposed them on the 2D images,and the mean values of the distances between corresponding 11 feature points in the 2D-3D face images were calculated.The superimposition of 2D-3D face images from the same individual was defined as the matching group,and the superimposition of 2D-3D face images from different individuals was defined as the non-matching group.Results In general,the average distance ranges of the corresponding feature points between the matching group and the non-matching group did not overlap(P<0.05).Conclusion The non-overlapping mean range preliminarily indicates that the individual identification method based on the overlay comparison of 2D-3D face images described in this paper is feasible for Han individuals.