生物力学

Of the late two years,in order to find out a kind of dental implant ing materialwhich would possess both the very good properties of biological compatibility,the chemical compatibility and the mechanical compatibility,an animal experi-mental preselection was accomplished by our research team with six kinds of im-planting material chosen from four main sorts of oral implant ing material(met-al,ceramic,high polymer and carbon),As the result of the Preselection,thematerial……bio-ceramic was chosen by ...

为了寻求生物相容性、化学相容性和力学相容性均好的种植材料，在口腔四大类种植材料(金属、陶瓷、碳素、高分子)中，选用6种材料作了动物实验预选。根据预选结果，选定以生物陶瓷为主攻方向，从而研制成功锆磷灰石陶瓷，以之进行了理化性能、生物学性能、及动物实验考查，合平种植要求。并以考查结果与钛合金、多晶氧化铝、单晶氧化铝、钛合金喷涂氧化铝、低温各向同性碳、聚砜种植作了比较，主要性能均较其它几种比较材料为优。经临床初试，锆磷灰石陶瓷的种植效果也较好，其界面为骨性结合。

Machinable bioactive glass-ceramics containing mica and fluorapatite were prepared by high-temperature melting. The glass-ceramics were analyzed by means of X-ray diffractometry, scanning electron microscopy with energy dispersive spectrometer and Fourier transform infrared reflection spectrometry. The bending strength, hardness and fracture toughness of the materials were measured.

摘 要：采用高温熔铸法制备可加工生物活性云母/氟磷灰石玻璃陶瓷；用X射线衍射、扫描电镜和傅里叶变换红外光谱分析等手段对材料的相组成和微观形貌进行研究，测定材料的抗弯强度、硬度和断裂韧性等力学性能；采用体外模拟体液浸泡法测试材料的生物活性。

Machinable bioactive glass-ceramics containing mica and fluorapatite were prepared byhigh-temperature melting. The glass-ceramics were analyzed by means of X-ray diffractometry, scanning electron microscopy with energy dispersive spectrometer and Fourier transform infrared reflection spectrometry. The bending strength, hardness and fracture toughness of the materials were measured.

摘 要：采用高温熔铸法制备可加工生物活性云母/氟磷灰石玻璃陶瓷；用X射线衍射、扫描电镜和傅里叶变换红外光谱分析等手段对材料的相组成和微观形貌进行研究，测定材料的抗弯强度、硬度和断裂韧性等力学性能；采用体外模拟体液浸泡法测试材料的生物活性。

According to the experiment results of degradation in field, degradation mechanism of the biodegradable mulch film can include four stages: the first, the material surface appeared deficiency while the surface area and interstice increased of material in the action of natural environment and microorganism; the second, along with the surface area and interstice of material increased and the gap strengthened, the chemical chain of the high polymer's principal chain broke as a result of the hydrolysis or the enzymatic effect in the action of hydration, causing the molecular weight and mechanics function descended; the third, the molecular of high polymer split the low polymer after its physical mechanical function descended, the material decomposed the fragments, the mass defect intensified; the fourth, the low polymer of fragments form in the natural environment, the microorganism, the biological enzyme became the smaller fragments, thus absorbed by the phagocytes, or further turn into CO2 and H2O due to hydrolysis.

根据田间降解试验结果推测，生物全降解地膜的降解机理可能包括四个阶段：第一，在自然环境、微生物作用下，材料表面出现缺陷，同时表面积增大、空隙增多；第二，随着材料表面积的增大、空隙的增多，吸水性增强，在自水合作用下，高聚物主链由于水解或酶解而使化学链断裂，导致分子量和力学性能下降；第三，在其物理机械性能下降后，高聚物分子链断裂为低聚物分子，材料裂解为碎片状，质量损失加剧；第四，碎片状低聚物在自然环境、微生物、生物酶作用下进一步水解变成尺寸更小的碎片，从而被吞噬细胞吸收，或进一步水解，生成CO2和H2O。

Through designing of composition and structure of the bioactive graded coating,innerstress and its distribution in the coating were analyzed and calculated, the resultsshowed that when composition distribution coefficient n was 1.5, a reasonable stressdistribution could be got, that was at the beginning of deposition the suspension containingrichly BG granules was used so that a rich BG granules layer, a good transitional layerbetween BG layer at the bottom and the coating could be obtained at the titanium alloy side,the bottom of the coating; the stress value near the interface and surface and its character,pressure stress or tensile stress, were decided by the character of its composition itself.Changing composition distribution coefficient n could only change the variation tendency ofstress in the coating, but did not change the stress distribution rule in the coating. Thethinner the coating is, the sharper stress variation in the coating is, which does not mean thatthicker coating is better because the thicker the coating is, the little the permitteddeformation of coating is, so the coating thickness should be thinner, for example, about50μm for bending applications, but for applications only bearing pure shear stress, such asroot of tooth implant, the coating can be thicker little, for instance, about 80～100μm. The study on electrification characteristic and electrophoresis deposition of HAand BG granules in aqueous and non-aqueous solution system found that EPD almost didn'toccur in aqueous solution system. However, because HA granules take position charges inabsolute alcohol, a homogeneous EPD be carried out on the cathode titanium alloy slice, but taking negative charge in absolute alcohol the BG granules not be deposited on the cathode. A guided HA crystallizing, 100～300nm, on surface of the BG granules be realized by metathetical reaction, which cover BG granules with HA microcrystals and make the covered BG granules taking position charges in absolute alcohol, sequentially realize the EPCD of the BG and HA granules on the cathode, so it is feasible to make a titanium alloy/BG/HA bioactive graded coating by making use of EPCD technology. The corrosion experiment of rich boron bioglass coating and plasma spray coating showed that split phase, rich boron and rich silicon phase, occurred during its preparation. In basic medium the corrosion behavior of 〓 BG coating showed uniformity corrosion, the corrosion mostly occurred at rich boron phase area, therefore batch formula design of BGshould avoid the occurring of split phase. The corrosion appearance of plasma spray coatingappeared a non-uniform corrosion, mostly occurred at the edge of the laminated HA moltendrops, and emerged an accelerated corrosion tendency, which will easyly lead to corrosioncrackles extending to the interface and the happening of osmotic interfacial corrosion, thatmay be one of the major reasons leading to the coating cracking-off in the later period. Thetesting results of thermal expansion coefficient of 〓 and 〓BG showed the thermalexpansion coefficient of 〓 BG matched with that of titanium alloy better, and 〓 BG couldsinter with titanium alloy into densification enamel layer at low temperature (720℃).

将Ti6Al4V合金在1000℃下进行真空热处理会降低其力学性能，且合金内的V元素会向表面富集，因此，钛合金真空热处理和表面涂层的烧结温度不能过高，即应低于其相转变点；通过对生物活性梯度涂层的组成和结构的设计，分析和计算了梯度涂层内的应力大小和分布，结果表明：对于本研究，当成分分布系数n=1.5时，可以获得较合理的涂层力学性能，即在沉积开始时，采用富含BG颗粒的悬浮液，以便在钛合金侧获得同底层BG有良好过渡的富BG涂层；梯度涂层界面和表面的应力大小、性质由材料组成本身的性质决定，改变成分分布系数，只能改变涂层内应力变化的趋势；涂层的厚薄不影响涂层内的应力分布规律，但涂层越薄，涂层内的应力变化越快，但这并不意味着涂层越厚越好，因为涂层越厚，涂层允许的变形越小，对于应用于弯曲受力部位的涂层而言，涂层应薄一点为好(50μm)；而对于仅纯受剪切应力的部位，如牙根种植体，涂层可适当加厚(80～100μm)；通过对HA和BG颗粒在水溶液体系和非水溶液体系中的带电特性和电泳沉积的研究发现，它们在水溶液体系中很难发生电沉积；在无水乙醇溶液中，HA颗粒带正电，可在阴极钛合金片上发生均匀的电泳沉积，而BG颗粒则带负电荷；利用复分解反应法，可以制得100～300nm的HA，通过诱导HA在BG颗粒表面结晶，可对BG颗粒进行表面包覆，获得了被HA包覆的BG颗粒，改变了BG颗粒表面的带电特性，使BG和HA颗粒在无水乙醇中均带上正电荷，从而实现了HA和BG颗粒在阴极上的共沉积。

Bioreactor is a kind of device intended for in vitro tissue culture that incubates the cells or tissues taken from living bodies in simulated physiological environment in vivo. On the basis of original cell culture, the present bioreactors apply biomechanical stimulation to simulate the stressed environment of articular cartilage in vivo.

生物反应器是一种体外的组织培养装置，它将活体内取出的细胞或组织在模拟体内生理环境下进行孵育培养使之生长分化，现有的生物反应器主要是在原有细胞培养的基础上加以力学刺激以模拟关节软骨在体内的应力环境。

The porous NiTi shape memory alloy possessed a high mechanical property and good biocompatibility, its unique pore structure confirmed the ingrowths of tissue and the transmission of body fluid, and made the combination of the implant and the body tissue much firmer. Porous NiTi shape memory alloy was a kind of biomedical material with excellent prospect of application.

国内外的研究表明，多孔NiTi合金具有优良的生物相容性和高的力学性能，其独特的孔隙结构可保证组织的长入和体液的传输，使植入物与人体骨组织的结合更加牢固可靠，多孔NiTi形状记忆合金是一种具有良好应用前景的生物医用材料。

The porous NiTi shape memory alloy possessed a high mechanical property and good biocompatibility, its unique pore structure confirmed the ingrowths of tissue and the transmission of body fluid, and made the combination of the implant and the body tissue much firmer.

国内外的研究表明，多孔NiTi合金具有优良的生物相容性和高的力学性能，其独特的孔隙结构可保证组织的长入和体液的传输，使植入物与人体骨组织的结合更加牢固可靠，多孔NiTi形状记忆舍金是一种具有良好应用前号的生物医用材料。

Methods:(1) bFGF was loaded with PLGA, PELA and gelatin microspheres. The pharmac characteristics of particle size distribution, loading efficiency, entrapment efficiency, bFGF release kinetics were evaluated with scanning electronic microscope, MTT and ELISA respectively. The prescription with the best pharmac characteristics and the highest bioactivity of bFGF was chosen for the next step.

（1）制备PLGA，PELA和明胶微球，通过扫描电镜和激光粒度分布仪测定其粒径分布；ELISA法测定微球溶出度，包封率，bFGF释出动力学；MTT法测定微球释出的bFGF的生物活性，筛选出一种具有较好药剂学性质和较高bFGF生物活性的微球载体材料。

The elasticity of soft sample,especially biomolecules,is one of the most attractive issues in the field of nano measurement with atomic force microscopy.

利用原子力显微镜技术研究柔软样品特别是生物分子的力学性质是当前生物物理的热点之一，但在柔软样品的压弹性方面的研究结果远离实际情况。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新