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BACKGROUND:Most of the silver coating materials prepared using active screen plasma technology in the past do not involve the nanotechnology field.The formed silver coating is in a"thin film"form,which is coated on the surface of the substrate,and the distribution of silver particles on the surface is uneven.Its long-term antibacterial ability is challenged. OBJECTIVE:To prepare nano silver coatings capable of being"buried"within stainless steel(SS)substrates using active screen plasma surface modification(ASPSM)and to observe antibacterial activity. METHODS:The nano-silver coating was prepared by ASPSM technique on stainless steel substrate.Three groups of coating samples were prepared by adjusting the bombardment time(1,2,and 4 hours),which were denoted as 1 h-Ag-ASPSM@SS,2 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,respectively.The antibacterial activity of the coatings was analyzed by antibacterial ring test and Gram staining.The antibiotic coating samples of gentamicin combined with vancomycin were prepared by using stainless steel as substrate and were recorded as ACNs.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were inserted into Staphylococcus aureus or Pseudomonas aeruginosa suspension,respectively.The long-acting(84 days)antibacterial activity of the samples was analyzed by coating plate method.Bone marrow mesenchymal stem cells were co-cultured with stainless steel,2 h-Ag-ASPSM@SS,and ACNs,respectively.CCK-8 assay,dead/alive staining,and lactate dehydrogenase activity of cell supernatant were detected.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were taken after continuous exposure to Staphylococcus aureus suspension for 12 weeks.The amount of residual viable bacteria on the surface of the material was evaluated by spread plate method.Vancomycin drug sensitive disk method was used to evaluate the resistance of residual live bacteria on the surface of materials. RESULTS AND CONCLUSION:(1)With increasing bombardment time,the diameter of nano silver on the sample surface and the silver content in the coating gradually increased.Among them,the 2 h-Ag-ASPSM@SS exhibited the highest surface silver content while forming uniformly spherical nanoparticles.(2)Antibacterial ring test and Gram staining results demonstrated that compared with 1 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,the 2 h-Ag-ASPSM@SS exhibited better inhibitory effect on Staphylococcus aureus and pseudomonas aeruginosa.After co-culturing with bacteria for 42 and 84 days,the number of viable bacteria on the spread plate method was significantly lower in the 2 h-Ag-ASPSM@SS group compared to the stainless steel and ACNs groups.After co-culturing with Staphylococcus aureus for 84 days and Pseudomonas aeruginosa for 42 days,the number of viable bacteria on the surface of the eluate from the ACNs group was higher than that of the stainless steel group.(3)CCK-8 assay,live/dead staining and lactate dehydrogenase activity of cell supernatant displayed that 2 h-Ag-ASPSM@SS did not have obvious cytotoxicity.ACNs showed obvious cytotoxicity.(4)After co-culture with Staphylococcus aureus for 12 weeks,the residual viable bacteria on the surface of 2 h-Ag-ASPSM@SS group was less than that of stainless steel group,and the residual viable bacteria on the surface of the ACNs group was more than that of stainless steel group.Compared with the stainless steel group,the sensitivity to vancomycin was significantly decreased in the ACNs group(P<0.001),and there was no significant change in sensitivity to vancomycin in 2 h-Ag-ASPSM@SS group(P>0.05).(5)The above results indicate that the silver nanoparticle coated stainless steel greatly improves the deposition efficiency of silver nanoparticles on the stainless steel surface and has long-lasting antibacterial properties and good cell compatibility.
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Objective To investigate the biomechanical properties and clinical effects of the unilateral/bilateral percutaneous vertebroplasty (PVP) on the treatment of osteoporotic vertebral compression fractures in elderly patients. Methods The finite element models of the unilateral/bilateral percutaneous vertebroplasty (PVP) in osteoporotic vertebral compression fractures were established to evaluate changes in strain and stress of the fractured vertebra after surgery. Eighty patients with osteoporotic vertebral compression fractures underwent unilateral or bilateral PVP were collected for retrospective analysis. The operation time,intraoperative fluoroscopy times,injected bone cement volume, bone cement leakage rate and visual analogue scales (VAS) score between the two groups were analyzed. Results The maximum strain and stress in unilateral PVP group were 1.18 times and 1.15 times of those in bilateral PVP group,respectively.The operation time and intraoperative fluoroscopy times in unilateral PVP group were obviously smaller than those in bilateral PVP group (P0.05).Conclusions The biomechanical effect of unilateral PVP was similar to that of bilateral PVP. The puncture needle localization of unilateral PVP for treating elderly patients with osteoporotic vertebral compression fractures had the advantage of less operation time and limited X-ray exposure.
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BACKGROUND:Mason II type and III type radial head fractures with massive bone are mainly treated by open reduction and metal fixation, but metal implants have to be removed in the second operation, which increased patients’ travail and financial burden. Absorbable screw/rod also can be used to treat radial head fractures, and has its special advantages due to the low price and no second operation. OBJECTIVE:To compare the clinical therapeutic effects of absorbable rod and Herbert screw for the treatment of Mason II or III type radial head fractures. METHODS:A total of 80 patients with Mason II and III type radial head fractures were equal y assigned to experimental and control groups. They received open reduction and internal fixation. The experimental group was treated with absorbable rod and the control group received Herbert screw. RESULTS AND CONCLUSION:A total of 79 patients were fol owed up for averagely 34 months. No significant difference in average operative time, fracture healing time, Broberg and Morrey elbow scores and incidence of complications was detected between the experimental and control groups (P>0.05). However, treatment costs were lower in the experimental group than in the control group (P<0.05). Results indicated that the therapeutic effects between absorbable rod and Herbert screw for Mason II or III type radial head fractures were similar. However, absorbable rod for radial head fractures can avoid the second operation for removal of the implant. Therefore, we recommend absorbable rod in the choice of internal fixation materials.
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BACKGROUND:At present, the methods of treating unstable comminuted radial head fractures contain open reduction and internal fixation and metal prosthesis replacement. There were success cases treated by the two methods, but some shortcomings simultaneously existed. OBJECTIVE:To compare the clinical therapeutic effects of replacement of the radial head with metal prosthesis with open reduction and internal fixation for the treatment of unstable comminuted radial head fractures. METHODS:A prospective randomized control ed analysis was performed in 45 cases of unstable comminuted radial head fractures. These cases received open reduction and internal fixation and metal prosthesis replacement. This study compared the Broberg and Morrey elbow joint function score and the incidence of complications after fixation, and performed statistical analysis. RESULTS AND CONCLUSION:The subjects were fol owed up for 1-5 years, averagely 2.8 years. According to Broberg and Morrey scores, the average score was 90.1 and the incidence of complications was 13.6%in the prosthesis replacement group. The average score was 76.8 and the incidence of complications was 47.9%in the open reduction. Significant differences were visible between the two groups (P<0.01). Compared with the open reduction group, prosthesis replacement for unstable comminuted radial head fractures obtained better joint function and lower incidence of complications.
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Objective Through detecting the levels of von willebrand factor (vWF) ,vWF-cleaving protease (vWF-cp)before and after percataneous coronary intervention (PCI) in patients with coronary atherosclerotic heart disease ,to evaluate the relationship between them .Methods According to the results of coronary angiography ,study objects were divided into control group (normal) and PCI group ( the diagnosis of coronary heart disease with PCI operation ) .Enzyme-linked immunosorbent assay (ELISA) was carrout to determin the levels of plasma vWF concentration and vWF-cp activity in plasma and statistical analysis .Results The pre-operative ,postoperative vWF levels in plasma in PCI group were significantly higher than that in the normal control group ;The plasma vWF levels after PCI were significantly higher than that in the group before PCI (P< 0 .05) ;vWF-cp level of the PCI group were lower than in the control group ,and postoperation is lower than preoperation ( P < 0 .05) .With the coronary artery lesion worsen ,the plasma level of vWF increased ,while the level of vWF-cp activity decreased .Conclusion vWF and vWF-cp levels with the severity of coronary atherosclerosis and thrombosis risk was increased in different decreased ,which may play an important role in the pathogenesis of acute coronary syndromes .Changes of vWF and vWF-cp level after PCI indicate that interventional therapy can increase the risk of thrombosis to some extent .