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1.
丝素蛋白作为生物医用材料的研究   总被引:13,自引:0,他引:13  
报道了以下研究,研制成同菌药物的丝素膜,它用于创面保护,能防止感染,加速面愈合;研制成多孔丝素膜,并研究了它们的结构和性能,多孔丝素膜能用作细胞培养的支架,药物缓释剂等;设计和研制成丝素成膜设备,该设备能用以生产丝素创面保护膜及其他医用膜。  相似文献
2.
建立新型国家预防医学体系战略研究   总被引:1,自引:0,他引:1       下载免费PDF全文
改革开放以来,伴随我国经济发展、劳动生活方式的改变,影响我国人民健康的主要疾病谱以及危险因素发生了巨大变化,现有的临床医学和预防医学教育体系已不再适应疾病预防控制、保障人民健康的实际需求。未来的卫生方针和政策、公共卫生和预防医学工作能否及时调整以应对这些变化和需求,是摆在我国卫生决策者面前的重大挑战。探讨建立适应实际需求的新型国家预防医学体系,并制定相应的卫生战略、战术和相关政策,从而实现有效利用有限的卫生资源,获取最大的健康保障效果。  相似文献
3.
高源  姚蓝 《声学技术》2006,25(2):91-97
ESPRIT算法是一种用信号旋转不变性来估计信号参数的方法,属于子空间分解技术。应用于矢量阵扩展孔径的方位估计时,则需要一定的算法去除其本征模糊。文中提出了一种适用于矢量水听器线阵的ESPRIT去模糊算法——MUSIC,并与另一种粗略估计去模糊的方法在性能上作出比较。仿真的结果证明:使用MUSIC方法不仅可以去除ESPRIT算法中的本征模糊,还可以克服线阵中的左右舷模糊问题,就不必进行归一化、不需要考虑声压传感器的存在。不论是单目标方位估计还是双目标分辨都具有更大的方位角估计适用范围和更强的稳定性。  相似文献
4.
对等离子喷涂HA/Ti复合涂层进行模拟体液和体外细胞试验,以考察涂层的生物学性能。结果指出,涂层经模拟体液浸泡后,表面覆盖一层碳酸磷灰石(carbonate-apatite),这表明涂层具有良好的生物活性,粗糙的涂层表面易于形成碳酸磷灰石,,模拟体液的浓度太小或pH值太大,均会导致碳酸磷灰石层不能在涂层表面形成,体外细胞试验显示,成骨细胞能在涂层表面紧密贴壁并正常生长,显示涂层具有优良的生物相容性  相似文献
5.
 通过对一个钢筋混凝土和钢煤斗的混和结构进行有限元分析,参照结构的实际破坏特征,找出破坏的原因,提出对该类结构设计有益的结论。采用了两种有限元软件,将分析结果进行了比较。讨论在兼顾准确和简洁的前提下如何建模和分析。同时也比较了几种建模方法的优劣,提出对有限元分析有参考价值的建议。  相似文献
6.
Osteomyelitis (bone infection) is often difficult to cure. The commonly-used treatment of surgical debridement to remove the infected bone combined with prolonged systemic and local antibiotic treatment has limitations. In the present study, an injectable borate bioactive glass cement was developed as a carrier for the antibiotic vancomycin, characterized in vitro, and evaluated for its capacity to cure osteomyelitis in a rabbit tibial model. The cement (initial setting time = 5.8 ± 0.6 min; compressive strength = 25.6 ± 0.3 MPa) released vancomycin over ~25 days in phosphate-buffered saline, during which time the borate glass converted to hydroxyapatite (HA). When implanted in rabbit tibial defects infected with methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis, the vancomycin-loaded cement converted to HA and supported new bone formation in the defects within 8 weeks. Osteomyelitis was cured in 87 % of the defects implanted with the vancomycin-loaded borate glass cement, compared to 71 % for the defects implanted with vancomycin-loaded calcium sulfate cement. The injectable borate bioactive glass cement developed in this study is a promising treatment for curing osteomyelitis and for regenerating bone in the defects following cure of the infection.  相似文献
7.
There is a great clinical need for biodegradable bile duct stents. Biodegradable stents made of an Mg–6Zn alloy were investigated in both vivo animal experiment and in vitro cell experiments. During the in vivo experiments, blood biochemical tests were performed to determine serum magnesium, serum creatinine (CREA), blood urea nitro-gen (BUN), serum lipase (LPS), total bilirubin (TB) and glutamic-pyruvic transaminase (GPT) levels. Moreover, tissue samples of common bile duct (CBD), liver and kidney were taken for histological evaluation. In the in vitro experiments, primary mouse extrahepatic bile duct epithelial cells (MEBDECs) were isolated and cultured. Cytotoxicity testing was carried out using the MTT method. Flow cytometry analyses with propidium iodide staining were performed to evaluate the effect of Mg–6Zn alloy extracts on cell cycle. The in vivo experiments revealed no significant differences (P > 0.05) in serum magnesium, CREA, BUN, LPS, TB or GPT before and after the operation. Based on the HE results, hepatocytes, bile duct epithelial cells, renal glomerulus and renal tubule tissues did not present significant necrosis. In the in vitro experiments, the cell relative growth rate curve did not change significantly from 20 to 40 % extracts. In vitro experiments showed that 20–40 % Mg–6Zn extracts are bio-safe for MEBDECs. In vivo experiments showed that Mg–6Zn stents did not affect several important bio-chemical parameters or, harm the function or morphology of the CBD, kidney, pancreas and liver. Our data suggested that this Mg–6Zn alloy is a safe biocompatible material for CBD.  相似文献
8.
Adsorption of plasma proteins to nanomaterial surfaces has a great influence on their bio-functionality. However, there is limited understanding of the relationship between the functional proteins in the protein corona and the biological identity of the materials. Here we show that the in situ generated thrombin in the protein corona of a Ca-zeolite surface displays a calcium-dependent, unusually high (~3,000 NIH U/mg) procoagulant activity, which is even stable against antithrombin deactivation. Removing the encapsulated Ca2+ in the zeolites leads to deactivation by antithrombin. Our observations suggest that the thrombin activity can be regulated by the inorganic surface and cations. Most importantly, our discovery indicates the link between the biomolecules in the protein corona and the procoagulant activity of the materials, providing a new molecular basis for the procoagulant mechanism for zeolite hemostatics.   相似文献
9.
To evaluate the ability of Mg–6Zn to replace titanium nails in the reconstruction of the intestinal tract in general surgery, we compared the Mg–6Zn and titanium implants with respect to their effects on rat’s intestinal tract by biochemical, radiological, pathological and immunohistochemical methods. The results indicated that Mg–6Zn implants started to degrade at the third week and disintegrate at the fourth week. No bubbles appeared, which may be associated with intestinal absorption of the Mg–6Zn implants. Pathological analyses (containing liver, kidney and cecum tissues) and biochemical measurements, including serum magnesium, creatinine, blood urea nitrogen, glutamic–pyruvic–transaminase and glutamic–oxaloacetic–transaminase proved that degradation of Mg–6Zn did not harm the important organs, which is an improvement over titanium implants. Immunohistochemical results showed that Mg–6Zn could enhance the expression of transforming growth factor-β1. Mg–6Zn reduced the expression of tumor necrosis factor at different stages. In general, our study demonstrates that the Mg–6Zn alloy had good biocompatibility in vivo and performed better than titanium at promoting healing and reducing inflammation. It may be a promising candidate for stapler pins in intestinal reconstruction.  相似文献
10.
It is well known that some microorganisms affect the corrosion of dental metal. Oral bacteria such as Actinomyces naeslundii may alter the corrosion behavior and stability of titanium. In this study, the corrosion behavior of titanium was studied in a nutrient-rich medium both in the presence and the absence of A. naeslundii using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). A. naeslundii was able to colonize the surface of titanium and then form a dense biofilm. The SEM images revealed the occurrence of micropitting corrosion on the metal surface after removal of the biofilm. The electrochemical corrosion results from EIS showed a significant decrease in the corrosion resistant (Rp) value after immersing the metal in A. naeslundii culture for 3 days. Correspondingly, XPS revealed a reduction in the relative levels of titanium and oxygen and an obvious reduction of dominant titanium dioxide (TiO2) in the surface oxides after immersion of the metal in A. naeslundii culture. These results suggest that the metabolites produced by A. naeslundii can weaken the integrity and stability of the protective TiO2 in the surface oxides, which in turn decreases the corrosion resistance of titanium, resulting in increased corrosion of titanium immersed in A. naeslundii solution as a function of time.  相似文献
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