Background First generation drug-eluting stents （DESs） were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported...Background First generation drug-eluting stents （DESs） were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported. Hence, cobalt chromium based DES coated with a bioabsorbable polymer was an alternate choice. Methods Cobalt chromium based DES with bioabsorbable polymer （Simrex stent） as well as control stents （Polymer stent and EXCELTM stent） were implanted into porcine arteries. At a designated time, angiography, quantitative coronary angiography （QCA） analysis, histomorphometry, and electron-microscopical follow-up were performed. Results A total of 98 stents of all the three groups were harvested. At week 24, percent diameter stenosis （%DS）, late loss （LL）, and percent area stenosis （%AS） of Simrex was （12.9±0.4）%, （0.35±0.02） mm, and （24.5±4.2）%, respectively, without significant difference in comparison to commercialized EXCELTM stent. Slight inflammatory reaction was seen around the stent strut of Simrex, just as in the other two groups. Electron-microscopical follow-up suggested that it might take 4-12 weeks for Simrex to complete its re-endothelialization process. Conclusions Cobalt chromium based, bioabsorbable polymer coated sirolimus-eluting stent showed excellent biocompatibility. During 24 weeks observation in porcine model, it was proved that this novel DES system successfully inhibited neointima hyperplasia and decreased in-stent stenosis. It is feasible to launch a clinical evaluation to improve the current prognosis of DES implantation.展开更多
Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang(Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrast...Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang(Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrastructure of four wax pores including trilocular,quinquelocular,and multilocular pores as well as tubular ducts,recording characteristics of their structure,size and distribution.We found that that the integument of the mealybug consists of three main layers-the procuticle,epidermis and basement membrane-and four sub-layers of the procuticle-the epicuticle,exocuticle,endocuticle and formation zone.The waxsecreting gland cells were closely arranged in epidermis.All of them were complex and composed of one central cell and two or more lateral cells.These complex cells possess a large common reservoir for collection and storage.Synthesized by the glandular cells,the wax is excreted outside integument through canals.展开更多
文摘Background First generation drug-eluting stents （DESs） were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported. Hence, cobalt chromium based DES coated with a bioabsorbable polymer was an alternate choice. Methods Cobalt chromium based DES with bioabsorbable polymer （Simrex stent） as well as control stents （Polymer stent and EXCELTM stent） were implanted into porcine arteries. At a designated time, angiography, quantitative coronary angiography （QCA） analysis, histomorphometry, and electron-microscopical follow-up were performed. Results A total of 98 stents of all the three groups were harvested. At week 24, percent diameter stenosis （%DS）, late loss （LL）, and percent area stenosis （%AS） of Simrex was （12.9±0.4）%, （0.35±0.02） mm, and （24.5±4.2）%, respectively, without significant difference in comparison to commercialized EXCELTM stent. Slight inflammatory reaction was seen around the stent strut of Simrex, just as in the other two groups. Electron-microscopical follow-up suggested that it might take 4-12 weeks for Simrex to complete its re-endothelialization process. Conclusions Cobalt chromium based, bioabsorbable polymer coated sirolimus-eluting stent showed excellent biocompatibility. During 24 weeks observation in porcine model, it was proved that this novel DES system successfully inhibited neointima hyperplasia and decreased in-stent stenosis. It is feasible to launch a clinical evaluation to improve the current prognosis of DES implantation.
基金National Natural Science Foundation of China(31070584)Natural Science Foundation of Shanxi Province(2010011042-12011021029-2)
文摘Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang(Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrastructure of four wax pores including trilocular,quinquelocular,and multilocular pores as well as tubular ducts,recording characteristics of their structure,size and distribution.We found that that the integument of the mealybug consists of three main layers-the procuticle,epidermis and basement membrane-and four sub-layers of the procuticle-the epicuticle,exocuticle,endocuticle and formation zone.The waxsecreting gland cells were closely arranged in epidermis.All of them were complex and composed of one central cell and two or more lateral cells.These complex cells possess a large common reservoir for collection and storage.Synthesized by the glandular cells,the wax is excreted outside integument through canals.
