Objective To explore the effect of nano-hydroxyapatite/collagen scaffolds incorporating ADM-PLGA microspheres in repairing large bone defects of rabbit femoral condyle. Methods Animal models of bone defects were induced in 21 New Zealand white rabbits by drilling holes in bilateral femoral lateral condyles , and the rabbits were equally divided into 3 groups:group A as the control group with the defects untreated , group B treated by filling with nano-hydroxyapatite/collagen scaffolds (NHAC), and group C treated by filling with the nano-hydroxyapatite/collagen scaffolds incorporating ADM-PLGA microspheres (ADM-PLGA-NHAC). At week 12 after implanting , the rabbits were all sacrificed for the implanted scaffolds , which were then examined by X-ray , and Micro-CT 3D reconstruction and in histology for evaluation of the new bone formation. Results X-ray, Micro-CT and the measurement and analysis of BMD indicated thatthere was no significant differencein the new bone formation between group B and group C (P > 0.05). The histological examination revealed that. 12 weeks after operation an evident number of new born bones were seen on the implanted scaffolds in groups B and C , while very few were seen scattering in group A. Conclusion The nano-hydroxyapatite/collagen scaffolds incorporating ADM-PLGA microspheres is effective in repairing bone defect without influencing the prosthetic process.

Objective To investigate the prevalence and endoscopic detection rate of proximal serrated polyps and to screen the risk factors. Methods The data of 9010 colonoscopies performed by 22 endoscopists between September 2016 and September 2017 were reviewed. The adenoma detection rate (ADR) and proximal serrated polyp detection rate (PSDR) were calculated, and the correlation between ADR and PSDR was estimated by Pearson correlation coefficients. Multivariate logistic regression was used to analyze PSDR among endoscopists. Results For all subjects, the mean ADR was 30. 07％ ( ranged from 20. 00％ to 40. 78％) and mean PSDR was 4. 70％ ( ranged from 1. 52％ to 9. 28％) . PSDR of males was 1. 38 times of that of females ( OR=1. 38, 95％CI:1. 13-1. 69, P<0. 01) . For 3560 cases ( 39. 51％) of 50 years and older subjects, the mean ADR was 45. 01％ ( 28. 99％-57. 78％) and mean PSDR was 6. 08％(2. 07％-10. 56％). PSDR was moderately correlated with ADR (r=0. 48, P=0. 02). PSDR of males was 1. 36 times of that of females (OR=1. 36, 95％CI: 1. 04-1. 80, P=0. 03). Endoscopist was a significant risk factor for detection of proximal serrated polyps ( P<0. 01) . Compared with endoscopist with the highest PSDR, odds ratio of other endoscopists ranged from 0. 16 (95％CI:0. 06-0. 40, P<0. 01) to 0. 83 (95％CI:0. 53-1. 32, P=0. 44) . Conclusion Proximal serrated polyps are more common in males, who are over 50 years old. The PSDR is highly variable and dependent on endoscopists. It is possible that a certain proportion of proximal serrated polyps are missed during colonoscopy.