ABSTRACT
In our previous studies,a novel cortex-like TiO2 coating was prepared on Ti surface through micro-arc oxidation (MAO) by using sodium tetraborate as electrolyte,and the effects of the coating on cell attachment were testified.This study aimed to investigate the effects of this cortex-like MAO coating on osseointegration.A sand-blasting and acid-etching (SLA) coating that has been widely used in clinical practice served as control.Topographical and chemical characterizations were conducted by scanning electron microscopy,energy dispersive X-ray spectrometer,X-ray diffraction,contact angle meter,and step profiler.Results showed that the cortex-like coating had microslots and nanopores and it was superhydrophilic,whereas the SLA surface was hydrophobic.The roughness of MAO was similar to that of SLA.The MAO and SLA implants were implanted into the femoral condyles of New Zealand rabbits to evaluate their in-vivo performance through micro-CT,histological analysis,and fluorescent labeling at the bone-implant interface four weeks after surgery.The micro-CT showed that the bone volume ratio and mean trabecular thickness were similar between MAO and SLA groups four weeks after implantation.Histological analysis and fluorescent labeling showed no significant differences in the bone-implant contact between the MAO and SLA surfaces.It was suggested that with micro/nanostructure and superhydrophilicity,the cortex-like MAO coating causes excellent osseointegration,holding a promise of an application to implant modification.
ABSTRACT
Objective:To compare the detection rate of colorectal adenoma (CRA) and its risk factors in different areas. Methods:Pa-tients with CRA from the 7th People's Hospital of Chongqing were designated to area group A (n=2182), and those from the 281 Hospi-tal of PLA in Qinhuangdao were designated to area group B (n=1866). The high risk group was screened on the basis of the following factors:①positive fecal occult blood;②colorectal cancer history of first-degree relatives;③intestinal adenoma history;④can-cer history;⑤change in defecation habit;and⑥history of at least two of the following:chronic diarrhea, chronic constipation, mu-cus and bloody stool, chronic appendicitis or appendix removal, and chronic cholecystitis or gallbladder removal. The detection rate of CRA and the high risk groups, the distribution of risk factors, and the detection rate of CRA in every risk factor in the two groups were compared. Results:The detection rate of CRA (15.6%) and the high risk group (25.8%) in area group A were similar to those in area group B (15.2%, 25.4%) (P>0.05). The distributions of risk factors from high to low in the two groups were⑤,⑥,①,③,②, and④. The distribution of risk factor⑤was higher in area group A (36.4%) than in area group B (30.6%) (χ2=3.900, P=0.048). The detec-tion rate of CRA in area group A (57.6%) with factor⑤was higher than that in area group B (44.1%) (χ2=6.131, P=0.013). Conclusion:The detection rate of CRA and the high risk group in the 7th People's Hospital of Chongqing were similar to those in the 281 Hospital of PLA. By contrast, the distributions of risk factors differ in the two area groups. Therefore, the screening direction of CRA in different areas should be based on the risk factors.