Evaluation of corneal cell growth on tissue engineering materials as artificial cornea scaffolds

The keratoprosthesis(KPro;artificial cornea)is a special refractive device to replace human cornea by using heterogeneous forming materials for the implantation into the damaged eyes in order to obtain a certain vision.The main problems of artificial cornea are the biocompatibility and stability of the tissue particularly in penetrating keratoplasty.The current studies of tissue-engineered scaffold materials through comprising composites of natural and synthetic biopolymers together have developed a new way to artificial cornea.Although a wide agreement that the long-term stability of these devices would be greatly improved by the presence of cornea cells,modification of keratoprosthesis to support cornea cells remains elusive.Most of the studies on corneal substrate materials and surface modification of composites have tried to improve the growth and biocompatibility of cornea cells which can not only reduce the stimulus of heterogeneous materials,but also more importantly continuous and stable cornea cells can prevent the destruction of collagenase.The necrosis of stroma and spontaneous extrusion of the device,allow for maintenance of a precorneal tear layer,and play the role of ensuring a good optical surface and resisting bacterial infection.As a result,improvement in corneal cells has been the main aim of several recent investigations;some effort has focused on biomaterial for its well biological properties such as promoting the growth of cornea cells.The purpose of this review is to summary the growth status of the corneal cells after the implantation of several artificial corneas.

中药调控的骨髓基质细胞复合生物活性玻璃修复骨缺损的组织学及电镜观察研究

目的：观察经中药骨碎补提取液培养的兔骨髓基质细胞与生物活性玻璃联合培养构建的组织工程化人工骨修复兔桡骨缺损的效果。方法：体外分离培养兔的骨髓基质细胞，经过传代并经低浓度骨碎补提取液培养扩增后，与生物活性玻璃联合立体培养构建组织工程化人工骨后，植入兔桡骨缺损处，与生物活性玻璃、自体髂骨以及空白组进行对比，通过大体形态、组织学及电镜观察各组骨缺损修复的效果。结果：植入组织工程化人工骨的兔桡骨缺损完全愈合，成骨效果与自体髂骨相似明显优于其他组。结论：经中药骨碎补提取液培养的骨髓基质细胞复合生物活性玻璃构建的组织工程化人工骨能很好完成骨缺损的修复。

基于人工神经网络不锈钢套珩磨加工油石特性参数的智能选择

在综合分析工件材料、材料状态、表面硬度和要求达到的加工表面质量与油石各参数之间关系的基础上,采用改进的GCAQBP人工神经网络算法,通过对输入输出参数进行编码优化,构建了不锈钢材料珩磨加工油石特性参数智能选择模型。通过实验研究,证明了该智能选择模型与传统经验选择相比,具有选择速度快、可靠性高等优点。课题研究为珩磨加工油石特性参数的选择提供了一种新的智能方法。

基于人工神经网络珩磨加工参数智能选择方法的研究

利用人工神经网络鲁棒性、容错性好的特点,通过对珩磨加工工艺参数的分析研究,首先构建了基于人工神经网络的珩磨加工参数智能选择模型;在理论模型研究的基础上,进行了实验研究,并通过实验数据对模型参数进行了优化。研究证明该方法用于珩磨加工工艺参数的选择具有较好的智能、可靠性高、选择操作简单、实用性强等优点。

精密阀套的珩磨加工

本文论述了精密阀套内孔珩磨加工的优点,阐明了阀套珩磨加工的主要工艺流程。推荐了一种新的交叉孔去毛刺方法,介绍了珩磨加工余量及珩磨油石的选择原则和珩磨行程、超程量的调整方法并明确了珩磨速度、珩磨压力的选择规范,通过实例论证了阀套内孔圆柱度的测量及修正方法。

超精密阀套内孔的珩磨工艺研究

本文阐明了珩磨加工超精密阀套内孔的详细工艺流程,推荐使用一种全浮式珩磨夹具及精密珩磨头,通过加工实例给出了粗珩、半精珩、精珩及预孔加工的工艺参数,可有效地保证超精密阀套内孔圆柱度0.5μm的形状精度。