Mutant strains of GO112 and BM302 with a high 2-keto-L-gulonic acid （2KLG） transformation rate induced by ion beam implantation were separately and combinatorially compared with the original strains GO29 and BM80 to...Mutant strains of GO112 and BM302 with a high 2-keto-L-gulonic acid （2KLG） transformation rate induced by ion beam implantation were separately and combinatorially compared with the original strains GO29 and BM80 to study the mutagenic effects of ion beam implantation. Both the sole GOl12 and mixed BM302：GOl12 demonstrated improved SNDH activity and 2KLG yield compared to the original strains. The mutant combinations of BM302：GOl12 showed a longer stationary phase and higher biomass than BM80：GO29. The mutant BM302 exhibited a stronger capacity to maintain a stable pH environment at mixed fermentation with Gluconobacter oxydans （G. oxydans） for 2KLG transformation and facilitated the growth of G. oxydans compared with the original strain BM80. The promotive capacity to L-sorbosone dehydrogenase （L-SNDH） from the supernate of BM302 was 1.6-fold higher than that of BM80. Genes encoded SNDH in GO29 and GOl12 were amplified and sequenced, and mutations including three transitions （CG →TA, CG →TA, GC → AT） and one transversion （AT→ TA） were confirmed from GO29 to GOl12. The corresponding amino acid was changed as Leu →Phe, Arg → Gln and Asn → Lys.展开更多
The deposition of high-quality diamond films and their adhesion on cemented carbides are strongly influenced by the catalytic effect of cobalt under typical deposition conditions. Decreasing Co content on the surface...The deposition of high-quality diamond films and their adhesion on cemented carbides are strongly influenced by the catalytic effect of cobalt under typical deposition conditions. Decreasing Co content on the surface of the cemented carbide is often used for the diamond film deposition. But the leaching of Co from the WC-Co substrate leading to a mechanical weak surface often causes a poor adhesion. In this paper we adopted an implant copper layer prepared by vaporization to improve the mechanical properties of the Co-leached substrate. The diamond films were grown by microwave plasma chemical vapor deposition from CH4:H2 gas mixture. The cross section and the morphology of the diamond film were characterized by scanning electron microscopy (SEM). The non-diamond content in the film was analyzed by Raman spectroscopy. The effects of pretreatment on the concentrations of Co and Cu near the interfacial region were examined by energy dispersive spectrum (EDS) equipped with SEM. The adhesion of the diamond on the substrate was evaluated with a Rockwell-type hardness tester. The results indicate that the diamond films prepared with implant copper layer have a good adhesion to the cemented carbide substrate due to the recovery of the mechanical properties of the Co-depleted substrate after the copper implantation and the formation of less amorphous carbon between the substrate and the diamond film.展开更多
BAEKGROUND： Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve g...BAEKGROUND： Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve grafting, what is the effect of nerve regeneration after repair？OB]EETIVE： To observe the local nervous status of the detected part of sciatic nerve repaired through subcutaneously implanting peripheral nerve allograft, and compare the effect with fresh autologous nerve grafting.DESTGN ： Contrast observation.SETTING ： Departments of Orthopaedics of Zhengzhou Fifth People＇s Hospital and First Hospital Affiliated to Chongqing Medical University.MATEREALS ： Totally 30 healthy adult Wistar male rats, with body mass of （200±20）g, were enrolled. Optical microscope （Olympus biological microscope BHS, Japan）, Electron microscope （H-600, Japan）,CM-2000 biomedical image analysis system （CM-2000,Beihang） and myoelectricity scanner （KEYPOINT, Denmark） were used in this experiment.METHODS ： This experiment was carried out in the Orthopaedic Laboratory of Chongqing Medical University between October 2000 and April 2002. ① Six rats were chosen as the donors for allogenic nerve grafting, and 15 mm sciatic nerve segment was chosen as graft. The other rats were randomly divided into two groups： allogenic nerve grafting group and autologous nerve grafting group, with 12 rats in each group. In the allogenic nerve grafting group, a skin incision was made on the posterior side of right thigh, and subcutaneous blunt dissection was performed prorsally a little, then allograft was implanted. Two weeks later, sciatic nerve was exposed at the posterior side of left thigh and cut respectively at 5 mm and another 10 mm away from pelvis. The donor nerve （with connective tissue veil） implanted subcutaneously on the right thigh was taken out. Sectioned connective tissue at the proximal end was trimmed and that at the distal end as done but reserved 10 mm in length, and inosculated antegradely at the nerve defect on the left side with 11/0 nylon line. Twelve rats in autologous nerve grafting group underwent a 10 mm sciatic nerve defect inci- sion on the right thigh and implant of fresh sciatic nerve from left thigh. The incision on the left thigh was repaired in situ. ②2,4,8 and 14 weeks after grafting, the nerve specimen of anastomosis segment was observed under optical microscope. Fourteen weeks after grafting, the ultrathin section of distal sciatic nerve was observed under transmission electron microscope. The number and size of regenerated axons at the cross section of anastomosis of proximal and distal sciatic nerve were analyzed with biomedical image analysis system. Neuroelectrophysiological change of in vivo sciatic nerve was detected with myoelectricity scanner.③ t test was used in the comparison of difference of measurement data.MAZN OUTCOME MEASURES ： ① Observation of anastomosis part of sciatic nerve under optical and electron microscopes in the two groups. ② Comparison of motor nerve conduction velocity, latent period and action potential peak as well as the number and size of cross-section of anastomosis part of proximal and distal sciatic nerve between two groups.RESULTS： ①Observation under optical microscope：Two weeks after grafting, neve axon of repaired region broke and medullary sheath denatured in the allogenic nerve grafting group and autologous nerve grafting group. At the same time, vascular engorgement and a little lymphocytes infiltration were found in the autologous nerve grafting group, but those were found worsened in the allogenic nerve grafting group. Four weeks after grafting, the intensity of the inflammatory reaction was similar between two groups, some collagen fibers at the proximal end proliferated; 8 weeks after grafting, the inflammatory reaction ended basically and the collagen fibers proliferated obviously in the two groups. ② Observation under electron microscope： Fourteen weeks after grafting, the structure of epineurium was in integrity and there were no obvious differences in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a few unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. ③The number and size of regenerated axons of anastomosis of proximal and distal sciatic nerve had no significant difference 14 weeks after grafting [（575.500±7.495） vs（585.700±11.172） axons/visual field ; （389.300±49.073） vs （407.600±0.283） axons/visual field;（6 423.830±119.911 ） vs （6 695.36± 84.287） μm^2/visual field = （ 5 980.110±74.572） vs（5 980.110±74.572） μm^2/visual field] （P 〉 0.05）. ④ Neuroelectrophysiological examination showed that there were no significant differences in motor nerve evoked potential latent pedod[（1.420±0.346）vs （1.237±0.250） ms] , motor nerve conduction velocity [（ 12.120±0.906 ） vs（13.020±0.599） m/s]and latent period of sciatic nerve [（0.500±0.380）vs （1.250±1.067） mV] of rats between two groups （P 〉 0.05）.CONCLUSTON： Although subcutaneous implant of peripheral nerve allograft has some inflammatory reactions, no obvious rejection is found. Repair results of two groups show that subcutaneous implant of allograft can promote nerve regeneration, which is similar to autologous nerve grafting.展开更多
Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.M...Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.Methods Two hundred and展开更多
The mechanism of improving the TID radiation hardened ability of partially depleted silicon-oninsulator（SOI） devices by using the back-gate phosphorus ion implantation technology is studied. The electron traps intro...The mechanism of improving the TID radiation hardened ability of partially depleted silicon-oninsulator（SOI） devices by using the back-gate phosphorus ion implantation technology is studied. The electron traps introduced in Si O2 near back Si O2/Si interface by phosphorus ions implantation can offset positive trapped charges near the back-gate interface. The implanted high concentration phosphorus ions can greatly reduce the back-gate effect of a partially depleted SOI NMOS device, and anti-total-dose radiation ability can reach the level of 1 Mrad（Si） for experimental devices.展开更多
Objective To study the effect of primary prevention of implantable cardioverter defibrillator(ICD)on sudden cardiac death(SCD)in patients with dilated cardiomyopathy.Methods A total of 36 patients with dilated cardiom...Objective To study the effect of primary prevention of implantable cardioverter defibrillator(ICD)on sudden cardiac death(SCD)in patients with dilated cardiomyopathy.Methods A total of 36 patients with dilated cardiomyopathy treated in our hospital from 2013-12 to2014-12 were studied including 29(80.6%)male and 7(19.4%)female with the mean age of(63±11.8)展开更多
Background Developmental dysplasia encompasses a wide spectrum of hip pathology ranging from a shallow acetabulum to a completely dislocated ＇high-riding＇ hip. It is a common cause of secondary osteoarthritis in you...Background Developmental dysplasia encompasses a wide spectrum of hip pathology ranging from a shallow acetabulum to a completely dislocated ＇high-riding＇ hip. It is a common cause of secondary osteoarthritis in young adults and is the underlying diagnosis in up to 48% of patients requiring total hip arthroplasty （THA） for coxarthrosis. The aim of this study was to evaluate efficiency and safety of THA using Zweym（311er hip implant in the treatment of severe osteoarthritis secondary to developmental dysplasia of the hip （DDH） in adults. Methods From January 2000 to February 2008, 35 patients （40 hips） with developmental dysplasia of the hip were included. Five were male and 30 were female, with ages ranging from 26 to 65 years and an average age of 45 years. According to Hartofilakidis classification, there were type I in 5 hips, type II in 20 hips, type III in 15 hips. All the patients were performed the THA using the Zweym011er hip implant. The preoperative average Harris score was 44. The bilateral arthroplasty was performed in 5 patients and the unilateral arthroplasty in 30 patients. The patients mainly suffered from pain and claudication. Clinical and radiological results were analyzed. The Harris score was used for outcome measurement. Results Thirty five patients （40 hips） were followed and the mean follow-up period was 46 months （ranged from 24 months to 96 months）. The latest follow-up average Harris score was 88.9 （97.1% of good rate）. All the patients were pain-free and there was no sign of infection, aseptic loosening and subsidence. Conclusions In summary, THA using Zweym011er hip implant is a good treatment method for severe osteoarthritis secondary to DDH in adults. The key techniques for the total hip replacement are as follows： good preoperative plan, firmly placing the acetabular component in the true acetabulum, proper preparation of proximal femur, suitable femoral component choosing and improving the techniques of the bone graft.展开更多
文摘Mutant strains of GO112 and BM302 with a high 2-keto-L-gulonic acid （2KLG） transformation rate induced by ion beam implantation were separately and combinatorially compared with the original strains GO29 and BM80 to study the mutagenic effects of ion beam implantation. Both the sole GOl12 and mixed BM302：GOl12 demonstrated improved SNDH activity and 2KLG yield compared to the original strains. The mutant combinations of BM302：GOl12 showed a longer stationary phase and higher biomass than BM80：GO29. The mutant BM302 exhibited a stronger capacity to maintain a stable pH environment at mixed fermentation with Gluconobacter oxydans （G. oxydans） for 2KLG transformation and facilitated the growth of G. oxydans compared with the original strain BM80. The promotive capacity to L-sorbosone dehydrogenase （L-SNDH） from the supernate of BM302 was 1.6-fold higher than that of BM80. Genes encoded SNDH in GO29 and GOl12 were amplified and sequenced, and mutations including three transitions （CG →TA, CG →TA, GC → AT） and one transversion （AT→ TA） were confirmed from GO29 to GOl12. The corresponding amino acid was changed as Leu →Phe, Arg → Gln and Asn → Lys.
文摘The deposition of high-quality diamond films and their adhesion on cemented carbides are strongly influenced by the catalytic effect of cobalt under typical deposition conditions. Decreasing Co content on the surface of the cemented carbide is often used for the diamond film deposition. But the leaching of Co from the WC-Co substrate leading to a mechanical weak surface often causes a poor adhesion. In this paper we adopted an implant copper layer prepared by vaporization to improve the mechanical properties of the Co-leached substrate. The diamond films were grown by microwave plasma chemical vapor deposition from CH4:H2 gas mixture. The cross section and the morphology of the diamond film were characterized by scanning electron microscopy (SEM). The non-diamond content in the film was analyzed by Raman spectroscopy. The effects of pretreatment on the concentrations of Co and Cu near the interfacial region were examined by energy dispersive spectrum (EDS) equipped with SEM. The adhesion of the diamond on the substrate was evaluated with a Rockwell-type hardness tester. The results indicate that the diamond films prepared with implant copper layer have a good adhesion to the cemented carbide substrate due to the recovery of the mechanical properties of the Co-depleted substrate after the copper implantation and the formation of less amorphous carbon between the substrate and the diamond film.
文摘BAEKGROUND： Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve grafting, what is the effect of nerve regeneration after repair？OB]EETIVE： To observe the local nervous status of the detected part of sciatic nerve repaired through subcutaneously implanting peripheral nerve allograft, and compare the effect with fresh autologous nerve grafting.DESTGN ： Contrast observation.SETTING ： Departments of Orthopaedics of Zhengzhou Fifth People＇s Hospital and First Hospital Affiliated to Chongqing Medical University.MATEREALS ： Totally 30 healthy adult Wistar male rats, with body mass of （200±20）g, were enrolled. Optical microscope （Olympus biological microscope BHS, Japan）, Electron microscope （H-600, Japan）,CM-2000 biomedical image analysis system （CM-2000,Beihang） and myoelectricity scanner （KEYPOINT, Denmark） were used in this experiment.METHODS ： This experiment was carried out in the Orthopaedic Laboratory of Chongqing Medical University between October 2000 and April 2002. ① Six rats were chosen as the donors for allogenic nerve grafting, and 15 mm sciatic nerve segment was chosen as graft. The other rats were randomly divided into two groups： allogenic nerve grafting group and autologous nerve grafting group, with 12 rats in each group. In the allogenic nerve grafting group, a skin incision was made on the posterior side of right thigh, and subcutaneous blunt dissection was performed prorsally a little, then allograft was implanted. Two weeks later, sciatic nerve was exposed at the posterior side of left thigh and cut respectively at 5 mm and another 10 mm away from pelvis. The donor nerve （with connective tissue veil） implanted subcutaneously on the right thigh was taken out. Sectioned connective tissue at the proximal end was trimmed and that at the distal end as done but reserved 10 mm in length, and inosculated antegradely at the nerve defect on the left side with 11/0 nylon line. Twelve rats in autologous nerve grafting group underwent a 10 mm sciatic nerve defect inci- sion on the right thigh and implant of fresh sciatic nerve from left thigh. The incision on the left thigh was repaired in situ. ②2,4,8 and 14 weeks after grafting, the nerve specimen of anastomosis segment was observed under optical microscope. Fourteen weeks after grafting, the ultrathin section of distal sciatic nerve was observed under transmission electron microscope. The number and size of regenerated axons at the cross section of anastomosis of proximal and distal sciatic nerve were analyzed with biomedical image analysis system. Neuroelectrophysiological change of in vivo sciatic nerve was detected with myoelectricity scanner.③ t test was used in the comparison of difference of measurement data.MAZN OUTCOME MEASURES ： ① Observation of anastomosis part of sciatic nerve under optical and electron microscopes in the two groups. ② Comparison of motor nerve conduction velocity, latent period and action potential peak as well as the number and size of cross-section of anastomosis part of proximal and distal sciatic nerve between two groups.RESULTS： ①Observation under optical microscope：Two weeks after grafting, neve axon of repaired region broke and medullary sheath denatured in the allogenic nerve grafting group and autologous nerve grafting group. At the same time, vascular engorgement and a little lymphocytes infiltration were found in the autologous nerve grafting group, but those were found worsened in the allogenic nerve grafting group. Four weeks after grafting, the intensity of the inflammatory reaction was similar between two groups, some collagen fibers at the proximal end proliferated; 8 weeks after grafting, the inflammatory reaction ended basically and the collagen fibers proliferated obviously in the two groups. ② Observation under electron microscope： Fourteen weeks after grafting, the structure of epineurium was in integrity and there were no obvious differences in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a few unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. ③The number and size of regenerated axons of anastomosis of proximal and distal sciatic nerve had no significant difference 14 weeks after grafting [（575.500±7.495） vs（585.700±11.172） axons/visual field ; （389.300±49.073） vs （407.600±0.283） axons/visual field;（6 423.830±119.911 ） vs （6 695.36± 84.287） μm^2/visual field = （ 5 980.110±74.572） vs（5 980.110±74.572） μm^2/visual field] （P 〉 0.05）. ④ Neuroelectrophysiological examination showed that there were no significant differences in motor nerve evoked potential latent pedod[（1.420±0.346）vs （1.237±0.250） ms] , motor nerve conduction velocity [（ 12.120±0.906 ） vs（13.020±0.599） m/s]and latent period of sciatic nerve [（0.500±0.380）vs （1.250±1.067） mV] of rats between two groups （P 〉 0.05）.CONCLUSTON： Although subcutaneous implant of peripheral nerve allograft has some inflammatory reactions, no obvious rejection is found. Repair results of two groups show that subcutaneous implant of allograft can promote nerve regeneration, which is similar to autologous nerve grafting.
文摘Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.Methods Two hundred and
基金Project supported by the Major Fund for the National Science and Technology Program,China(No.2009ZX02306-04)the Fund of SOI Research and Development Center(No.20106250XXX)
文摘The mechanism of improving the TID radiation hardened ability of partially depleted silicon-oninsulator（SOI） devices by using the back-gate phosphorus ion implantation technology is studied. The electron traps introduced in Si O2 near back Si O2/Si interface by phosphorus ions implantation can offset positive trapped charges near the back-gate interface. The implanted high concentration phosphorus ions can greatly reduce the back-gate effect of a partially depleted SOI NMOS device, and anti-total-dose radiation ability can reach the level of 1 Mrad（Si） for experimental devices.
文摘Objective To study the effect of primary prevention of implantable cardioverter defibrillator(ICD)on sudden cardiac death(SCD)in patients with dilated cardiomyopathy.Methods A total of 36 patients with dilated cardiomyopathy treated in our hospital from 2013-12 to2014-12 were studied including 29(80.6%)male and 7(19.4%)female with the mean age of(63±11.8)
文摘Background Developmental dysplasia encompasses a wide spectrum of hip pathology ranging from a shallow acetabulum to a completely dislocated ＇high-riding＇ hip. It is a common cause of secondary osteoarthritis in young adults and is the underlying diagnosis in up to 48% of patients requiring total hip arthroplasty （THA） for coxarthrosis. The aim of this study was to evaluate efficiency and safety of THA using Zweym（311er hip implant in the treatment of severe osteoarthritis secondary to developmental dysplasia of the hip （DDH） in adults. Methods From January 2000 to February 2008, 35 patients （40 hips） with developmental dysplasia of the hip were included. Five were male and 30 were female, with ages ranging from 26 to 65 years and an average age of 45 years. According to Hartofilakidis classification, there were type I in 5 hips, type II in 20 hips, type III in 15 hips. All the patients were performed the THA using the Zweym011er hip implant. The preoperative average Harris score was 44. The bilateral arthroplasty was performed in 5 patients and the unilateral arthroplasty in 30 patients. The patients mainly suffered from pain and claudication. Clinical and radiological results were analyzed. The Harris score was used for outcome measurement. Results Thirty five patients （40 hips） were followed and the mean follow-up period was 46 months （ranged from 24 months to 96 months）. The latest follow-up average Harris score was 88.9 （97.1% of good rate）. All the patients were pain-free and there was no sign of infection, aseptic loosening and subsidence. Conclusions In summary, THA using Zweym011er hip implant is a good treatment method for severe osteoarthritis secondary to DDH in adults. The key techniques for the total hip replacement are as follows： good preoperative plan, firmly placing the acetabular component in the true acetabulum, proper preparation of proximal femur, suitable femoral component choosing and improving the techniques of the bone graft.
