HA/TiO 2 composite coating were fabricated via adding TiO 2 powder in the electrolyte by electrodeposition.The influence of current dens ity and deposition time on the content of TiO 2 in the coating,the influence of ...HA/TiO 2 composite coating were fabricated via adding TiO 2 powder in the electrolyte by electrodeposition.The influence of current dens ity and deposition time on the content of TiO 2 in the coating,the influence of the content of TiO 2 in the coating on the bonding strength of coating and the influence of sinte ring temperature on the structure and the bonding strength of coating were inves tigated.The experiment results show that the content of TiO 2 in the coating increase with reducing the current density and prolonging the deposition time,the bonding strength improve with increasing the content of TiO 2 in the coating,which can obtain18.7MPa when the weight percent TiO 2 in the coating attain72.2%.The addition of TiO 2 in the coating reduces the thermal expansion co - efficient of the coating,improves the bonding strength of coating and change s the fracture mechanism of the coat - ing from adhesion failure to cohesive failure.HA in the composite coatings i s decomposed by the catalysis reac - tion of TiO 2 at the temperature of sinter850 ℃ .Differential scanning calorimetry and X - ray diffractometry analy - ses showed that the chemical reaction between HA and TiO 2 lead to the product are α- TCP and CaTiO 3 at the temperature of sinter1200 ℃ .In order to prevent the coating from decomposing and attain hign bonding st rength,the sintering temperature should be less than820 ℃ .展开更多
Objective：To implant 80 mm-long artificial esophagi constructed of biomaterial in dogs, observe the perioperative survival rates and the incidence of postoperative complications, and study the mechanisms of postopera...Objective：To implant 80 mm-long artificial esophagi constructed of biomaterial in dogs, observe the perioperative survival rates and the incidence of postoperative complications, and study the mechanisms of postoperative healing. Methods： Specimens of the implanted esophagus, the ＂neo-esophagi＂, were taken for histopathologic study 1, 3, 6, 12, 24 months after operation. Results： The incidence of anastomotic leakage after the artificial esophagus implantation was 3.33%. The perioperative survival rate was 96.67%. The incidence of postoperative stenosis in the ＂neo-esophagi＂ was 81.48%; the stenoses were treated by expanding with esophagoscopy and implanting a stent. Epithelization of the mucosa in the ＂neo-esophagi＂ was completed in 3 to 6 months after surgery Structures such as submucosal muscle layers, mucous glands, nerve fibers, capillaries, etc. were regenerated after 12 months, and then reconstruction of the fibrous connective tissue layer was completed. Conclusion： Implanting a biomaterial artificial esophagus accomplishes safe reconstruction of defects in the esophagus. Advanced cellular structure of ＂neo-esophagus＂ can be regenerated after 1 year. Postoperative stenosis, which is related to hyperplasia and retraction of scar tissue, is still the most common complications which limiting the clinical application of the artificial esophagus.展开更多
文摘HA/TiO 2 composite coating were fabricated via adding TiO 2 powder in the electrolyte by electrodeposition.The influence of current dens ity and deposition time on the content of TiO 2 in the coating,the influence of the content of TiO 2 in the coating on the bonding strength of coating and the influence of sinte ring temperature on the structure and the bonding strength of coating were inves tigated.The experiment results show that the content of TiO 2 in the coating increase with reducing the current density and prolonging the deposition time,the bonding strength improve with increasing the content of TiO 2 in the coating,which can obtain18.7MPa when the weight percent TiO 2 in the coating attain72.2%.The addition of TiO 2 in the coating reduces the thermal expansion co - efficient of the coating,improves the bonding strength of coating and change s the fracture mechanism of the coat - ing from adhesion failure to cohesive failure.HA in the composite coatings i s decomposed by the catalysis reac - tion of TiO 2 at the temperature of sinter850 ℃ .Differential scanning calorimetry and X - ray diffractometry analy - ses showed that the chemical reaction between HA and TiO 2 lead to the product are α- TCP and CaTiO 3 at the temperature of sinter1200 ℃ .In order to prevent the coating from decomposing and attain hign bonding st rength,the sintering temperature should be less than820 ℃ .
基金Supported by the Science Foundation from Sci-Tech Office of Guangdong Province(A3020103)Science Foundation from Sci-Tech Bureau of Guangzhou City(2004Z3-E0551).
文摘Objective：To implant 80 mm-long artificial esophagi constructed of biomaterial in dogs, observe the perioperative survival rates and the incidence of postoperative complications, and study the mechanisms of postoperative healing. Methods： Specimens of the implanted esophagus, the ＂neo-esophagi＂, were taken for histopathologic study 1, 3, 6, 12, 24 months after operation. Results： The incidence of anastomotic leakage after the artificial esophagus implantation was 3.33%. The perioperative survival rate was 96.67%. The incidence of postoperative stenosis in the ＂neo-esophagi＂ was 81.48%; the stenoses were treated by expanding with esophagoscopy and implanting a stent. Epithelization of the mucosa in the ＂neo-esophagi＂ was completed in 3 to 6 months after surgery Structures such as submucosal muscle layers, mucous glands, nerve fibers, capillaries, etc. were regenerated after 12 months, and then reconstruction of the fibrous connective tissue layer was completed. Conclusion： Implanting a biomaterial artificial esophagus accomplishes safe reconstruction of defects in the esophagus. Advanced cellular structure of ＂neo-esophagus＂ can be regenerated after 1 year. Postoperative stenosis, which is related to hyperplasia and retraction of scar tissue, is still the most common complications which limiting the clinical application of the artificial esophagus.
