CFRC/HAP 生物材料复合粘结因素和种植体骨界面研究

主要研究了在采用国产ＣＦＲＣ＿Ⅱ材料加工出表面层镶嵌低温烧结ＨＡＰ组分样品时，硼系生物玻璃作为ＣＣＨ生物材料复合粘结剂的作用机理。通过种植体以及其界面周围组织结构的ＳＥＭ和ＥＤＳ分析，初步查明ＣＣＨ复合材料表面层的结构形态，各组成之间以及复合体与种植界面新生骨组织机体的相互作用机制。     

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F0 by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.     

聚羟基丁酸酯缓释微粒作用下的埋植给药系统

制备了以壳聚糖水凝胶为基质的温度敏感型、可注射、并能够在体内生物降解的新型皮下埋植制剂,考察了该制剂中水溶性小分子药物的体外释放规律。为降低该类药物的释放速度,首先利用溶剂非溶剂法,以生物可降解的聚羟基丁酸酯为骨架,制备了抗癌药物5-氟尿嘧啶的微粒。在优化配比下,微粒收率达90%以上,包封率95%左右;然后将微粒温敏型水凝胶耦合制成复合给药系统。药物微粒化与温敏型水凝胶的耦合有效地控制了药物植入初期的“突释”问题,并将药物的释放周期延长至将近10个月。     

加载方向对种植体骨界面上应力分布的影响

目的:探讨加载方向对种植义齿周骨界面应力分布的影响,为临床种植提供参考。方法:用三维有限元法给两种种植分别从垂直、45°及水平方向施加200N载荷,并对其骨界面上应力分布进行分析。结果:种植体颊侧颈部骨界面是高应力集中区;水平向加载时,应力水平最高,是45°及垂直向加载时的2～3倍。结论:在牙科美学范畴内,适当减小种植体植入角度,可以改善种植体周骨界面上所受到的应力水平。     

用插销法研究低碳和低合金钢焊接接头的应力腐蚀

提出用插销法作为评定低碳、低合金钢焊接接头应力腐蚀破裂（ＳＣＣ）性能的方法，并以施加于插销的临界初始应力δｉｍｐＳＣＣ作为评定ＳＣＣ抗力的指标。用不同型号焊条焊制的２０ｇ和１６ＭｎＲ钢焊接接头ＨＡＺ各区及焊缝在沸腾混合硝盐溶液（ＭＮＳ）中的ＳＣＣ第三性的试验结果表明：以插销法的σｉｍｐＳＣＣ与分别以恒载拉伸法的σＳＣＣ和以悬臂弯曲法的Ｊ１ＳＣＣ评定的接头各区ＳＣＣ抗力的变化规律是一致的。文中还对Ｓ     

Effects and complications of placement of motility coupling post in porous polyethylene orbital implants

Objective： To investigate the effects and complications of primary and secondary placements of motility coupling post （MCP） in the unwrapped porous polyethylene orbital implant （PPOI） following enucleation. Methods： We investigated 198 patients who received PPOI implantation following the standard enucleation procedure in the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China, from 2002 to 2004. These patients were subgrouped into PPOI-only patients （112 cases, received PPOI following enucleation）, primary MCP patients （46 cases, received primary placement of MCP during PPOI operation）, and secondary MCP patients （40 cases, received secondary placement ofMCP 6 months after the initial surgery）. Effects and complications among these three groups were compared. Results： The PPOI-only patients took shorter treatment course when compared with other two MCP groups （P〈0.001）, without significant difference noted between the two MCP groups. However, the two MCP groups had better prosthetic motility than PPOI-only group （P〈0.001）, without significant difference between the two MCP groups. In the early stage, 2 eyes in the PPOI-only group and l eye in the primary MCP group had PPOI infection. In PPOI-only group, 3 （2.68%） eyes had PPOI exposure, which occurred after fitting the prostheses; 4 eyes （8.70%） in primary MCP group and 1 eye （2.50%） in secondary MCP had PPOI exposure, which occurred before fitting the prostheses. After prosthesis was fit successfully, the excessive discharge and granuloma were 33.9% and 1.79% in PPOI group-only, 53.3% and 8.9% in primary MCP group, and 52.5% and 7.5% in secondary MCP group, respectively. Conclusion： Both primary and secondary placements of MCP into the PPOI following enucleation can help patients to obtain desirable prosthetic motility, but may be associated with more complications. The primary placement of MCP with skilled operation in selected patients is more recommendable than secondary plac     

湖羊母体埋植褪黑素对其初生羔羊皮毛品质的影响

研究了湖羊母体埋植不同剂量的褪黑素对其初生羔羊皮毛品质的影响,与埋植空白管的对照组比较,高剂量褪黑素（１５０ｍｇ·只＾－１）虽对提高羔羊的初生体质量有一定的好处,但对其皮毛品质参数没有影响;低剂量褪黑素（１５ｍｇ·只＾－１）对所产羔羊的皮毛品质有所改善,该组皮毛品质参数均值和甲级皮张百分率明显高于对照组,由此可见,在湖羊母体埋植低氏剂量的外源裉黑素对提高羔皮品质具有直接而积极的意义。该操作简单且成     

丙酸睾酮埋植剂体内释放模型的建立

探讨丙酸睾酮(丙睾)埋植剂在大鼠体内的药物释放过程,建立释放模型。将丙睾埋植剂分别包装成2支和4支组,随后将70只雄性Wistar大白鼠按体重随机分为两组,在两组大鼠背部皮下分别植入2支和4支丙睾埋植剂。在丙睾埋植剂植入大白鼠体内前0 d及植入后的1 d、3 d、7 d、14 d、30 d、60 d、90 d、180 d,采用断尾方式采集2支组大鼠血样1 mL,用睾酮放射免疫试剂盒检测血清中睾酮含量。在埋植后的14 d、30 d、60 d、90 d、180 d将动物体内的丙睾埋植剂取出,通过重量的差值计算药物在体内的释放量。结果丙睾埋植剂在体内的累积释放量随着埋植时间的延长呈逐渐上升趋势。至180 d时,两组埋植剂内药物几乎全部释放出来。而体内血清中睾酮浓度变化趋势正好与体内释放量变化趋势相反,随着埋植天数的增加,睾酮浓度逐渐下降。经过释放模型验证,丙酸睾酮埋植剂体内释放遵循一级释放方程。埋植剂中的丙睾可以通过硅胶囊管壁渗透出来,被吸收入血后,可使血清中睾酮浓度维持几个月之久,可以认为本埋植剂是一种能长期缓慢释放丙睾药物的控释给药系统。     

上颌骨缺损颧种植体功能设计及生物力学评价

利用Branemark颧骨种植体,结合显微外科骨移植技术重建半侧缺损和全缺损上颌骨的形态和功能,并对重建的生物力学效果进行评价.基于CT扫描和图像及图形处理技术,建立标准人的模块化颅骨三维几何和有限元力学模型.基于该模型,模拟不同颌面骨缺损状态,设计上颌骨半侧和全缺损颧种植体长度、植入位置、植入方向,及常规种植体分布和数量,并利用有限元方法评价该设计的生物力学性能.结果表明,腓骨移植Branemark颧骨种植体种植修复半、全侧上颌缺损模型的应力分布中,应力最大值出现在颧种植体植入颧骨的颈部,颧种植体上应力值较周围支持组织的大,起到了颧突支柱对牙合力的传导作用;种植体结构中弯曲变化的位移不明显,并且种植体整体位移在颧骨附近逐渐减小为零.故腓骨重建颧种植修复上颌骨缺损方法能够有效传导牙合力,其周围支持组织具有良好的应力分布,是一种安全有效修复上颌缺损、恢复咀嚼功能的临床方法.     

AISI316L奥氏体不锈钢在摸拟人体组织液中腐蚀疲劳裂纹萌生的初步研究

AISI316L奥氏体不锈钢是较常用的金属植入材料之一.但在临床应用中,由它制成的植入物特别是全髋关节,常因腐蚀疲劳破断而失效.本文对316L不锈钢在Hank’s溶液中的腐蚀疲劳裂纹萌生机理进行了初步研究.结果发现,在Hank’s溶液中,自然钝化的316L不锈钢在稳定钝化态下,裂纹的萌生是由交变应力引起的微观塑性变形和Hank’s溶液交互作用的结果;在有点蚀产生的非钝化态下,裂纹的萌生是点蚀和腐蚀疲劳相叠加的结果.316L不锈钢经离子氮化表面处理后,提高了在Hank’s溶液中的抗点蚀能力,但在外加腐蚀电位的苛刻条件下,困氮化层发生晶间腐蚀和脱落而加速了裂纹的萌生