Induction of immune tolerance with heart-thymus composite allotransplantation in rats

Objective To study on the role of thymus transplantation for heart allograft in rats. Methods Vascularized heart-thymus combined transplantation was performed with microsurgical technique. Graft survival, histopathology, level of IL-2, IL-4 and its mRNA expression in serum and cardiac grafts were investigated. Results Heart-thymus combined transplantation achieved effect in the prolongation of cardiac graft survival with short-term administration of cyclosporine. Conclusions Vascularized thymus transplantation induced immune tolerance in thymectomized rats.     

Establishment and improvement of model of vascularized heart-thymus composite transplantation in rats

Objective To establish and improve the model of heart-thymus composite transplantation. Methods Vascularized both lobes of the thymus is transplanted heterotopically with the heart as a composite graft in rats.This technique was developed and assessed, and viability of the grafts was evaluated histologically. Results Donor operation costed 38. 5 ± 3. 52 min, vascular anastomosis costed 25.0 ± 3. 28 min, operating successful rate was 90%, acute rejection was observed in SD-Wistar group, viable thymus with normal microarchitecture was maintained in Wistar-Wistar group. Conclusions The improved novel technique for combined heart-thymus transplantation is a valuable method for study of the role of thymus in transplantation immunity.     

Establishment and improvement of model of vascularized heart-thymus composite transplantation in rats

Objective To establish and improve the model of heart-thymus composite transplantation. Methods Vascularized both lobes of the thymus is transplanted heterotopically with the heart as a composite graft in rats. This technique was developed and assessed, and viability of the grafts was evaluated histologically. Results Donor operation costed 38.5 ± 3.52 min, vascular anastomosis costed 25.0 ± 3.28 min, operating successful rate was 90%, acute rejection was observed in SD-Wistar group, viable thymus with normal microarchitecture was maintained in Wistar-Wistar group. Conclusions The improved novel technique for combined heart-thymus transplantation is a valuable method for study of the role of thymus in transplantation immunity.     

Effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac allo-transplantation in rats

Objective To observe the effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac silo-transplantation in rats. Methods Rats were randomly assigned to 9 groups, heart allo-transplantation were performed in abdominal site with micro-surgical technique. Recipients with allografts were treated with different doses of FTY720 and(or) ICAM-1 mAb. Graft survival, histopathology andlevel of serum IL-2, IFN-γ, IL-4, IL-10were investigated. Results Low doses of FTY720 (lmg/kg) combined with ICAM-1 mAb achieved synergistic effect in the prolongation of cardiac graft survival, combination index(CD =0.67. Conclusion Concomitant therapy of FTY720 and ICAM-1 mAb achieved a synergistic effect in the prolongation of heart allograft survival in rats.     

Effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac allo-transplantation in rats

Objective To observe the effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac allo-transplantation in rats. Methods Rats were randomly assigned to 9 groups, heart allo-transplantation were performed in abdominal site with micro-surgical technique. Recipients with allografts were treated with different doses of FTY720 and (or) ICAM-1 mAb. Graft survival, histopathology and level of serum IL-2, IFN-γ, IL-4, IL-10 were investigated. Results Low doses of FTY720 (1mg/kg) combined with ICAM-1 mAb achieved synergistic effect in the prolongation of cardiac graft survival, combination index(CI)=0.67. Conclusion Concomitant therapy of FTY720 and ICAM-1 mAb achieved a synergistic effect in the prolongation of heart allograft survival in rats.     

Objective function of cost in optimal tolerance allocation

An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coefficient is derived,which takes into account of several factors affecting the manufacturing cost,including the forming means of the blank,size,machining surface features,operator’s skills and machinability of materials. The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance,and,hence,an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient,the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation,which indicates the increase of the tolerance’s effects on the total manufacturing cost and,therefore,a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient,accurate and practicable.     

容侵模型分析

随着入侵手段的不断变化、发展,防火墙和入侵检测技术已经不能完全保证系统的安全性,如果在系统被入侵后还要提供一定的服务或者是降级的服务,这就需要容侵系统来维护这些服务的继续.分析了最近国际、国内的一些主要的容侵模型,并针对不同的模型给出一定的评价.通过这些分析可知,容侵技术继入侵检测、防火墙技术之后必将成为未来网络服务器的必备技术.     

融合免疫机制的协同进化模型

针对传统进化算法在计算效能方面存在的一些问题,借鉴协同进化算法的思想,提出了一种融合免疫机制的协同进化模型。该模型通过多个子种群各自分别进化以保持整个种群的多样性。在每次迭代进化过程中,各个子种群分别选择精英抗体并进行免疫记忆。随后各个子种群分别以不同的算法进行变异。若变异后抗体的适应度降低,则利用精英抗体对其进行引导操作。群体间的协作包括子种群间若干个抗体的随机交叉和子种群间的大规模迁移。最终进行免疫代谢,去除群中的弱适应度个体。算法反复迭代进行以上操作,直至达到既定目标或预定的循环迭代次数。通过对13个标准测试函数进行的仿真实验显示,该模型在搜索最优解或满意解时均优于传统的进化算法,同时在寻优效率上有较大的提升。     

模拟退火算法在并行公差优化中的应用

根据并行公差设计的特点,建立了并行公差设计的优化数学模型,该模型以总加工成本最小为目标函数,以装配功能要求、加工方法选择、加工余量公差、经济加工精度范围等为约束条件,将模拟退火算法应用于并行公差优化设计中,并给出了具体的算法流程。通过实例验证了其算法的正确性。     

CAD／CAPP集成中公差的模糊优化设计

在分析CAD／CAPP公差设计现状的基础上,指出在CAD／CAPP公差设计中模糊因素存在的客观性和不可避免性,运用模糊优化理论,提出了一种新的并行公差模糊优化设计数学模型．最后给出实例并分析了其结果．     

容错降维观测器设计及其应用

针对系统的不可靠输出，提出了一种新的降维观测器设计方法，该方法对系统输出不可靠具有容错能力，并且当输出正常后能够恢复对系统状态变量的跟踪，通过应用于某导弹姿控系统仿真计算证明了该方法的有效性和可行性。     

免疫算法在火电机组优化组合中的应用

为克服传统优化算法和遗传算法无法快速有效得到全局最优解的问题,提出了应用免疫算法进行机组组合优化.目标函数对应于免疫算法的抗原,优化解对应于免疫算法中的抗体,通过适应度来评价抗体与抗原的结合程度,与抗原结合最好的抗体就是问题的最优解.对机组运行状态的持续时间进行抗体编码,改善了算法的收敛性.经实例验证表明,优化免疫算法具有良好的搜索性能,是解决机组优化组合问题的有效方法.     

AutoCAD中尺寸公差的标注和修改研究

通过实例阐述了在AutoCAD2007绘图环境下机械制图中涉及到的尺寸公差的标注和修改的简便方法和技巧,以到达提高绘图效率的目的。     

图纸标注公差的计算机辅助公差设计

讨论了产品设计阶段设计公差的两类确定方法,在给出数模的基础上,按简单情况及通常的加工习惯,针对产品某项精度所关联之零件主要尺寸的公差及基本偏差,给出了计算机辅助公差设计的流程。     

求解非满载车辆调度问题的免疫遗传算法

非满载车辆调度问题是车辆调度问题中的一个基本问题,由于它是一个典型的NP难题,传统方法的求解结果往往不能令人满意.曾有研究将传统的遗传算法用于求解非满载车辆调度问题,但是由于遗传算法在遗传后期的波动现象,导致了迭代次数过大和准确率不高.该实验根据生物免疫系统的机理提出的免疫遗传算法,结合了遗传算法的进化操作和生物免疫中的浓度机制,通过抗体的期望繁殖率实现对抗体的促进和抑制,改善未成熟收敛.该算法是在传统遗传算法全局随机搜索的基础上,借鉴生物免疫机制中抗体的多样性保持策略,改善了传统遗传算法的群体多样性,通过与遗传算法的比较,结果表明,该算法不仅收敛,而且具有更好的全局和局部搜索能力和收敛速度.     

改进免疫克隆选择算法在VRP中的应用

针对在求解车辆路径问题(VRP)中免疫克隆选择算法收敛速度慢,遗传算法易陷入局部最优解的缺点,对抗体亲和力求解方法做了改进.提出了基于亲和力排序的抗体相似性矩阵的概念,并将其应用于抗体抑制策略,进而设计出改进免疫克隆选择算法.仿真结果表明该算法比遗传算法求的解的质量更高,收敛速度比免疫克隆选择算法快.     

免疫蚁群算法在电力系统无功优化中的应用

将人工免疫算法和蚁群算法相结合形成免疫蚁群算法,运用免疫机理提取疫苗获得初始解,通过免疫操作加快算法收敛速度,并用基于浓度的选择机制抑制算法的＂早熟＂.将该算法用于求解电力系统无功优化问题进行仿真,结果表明它的收敛速度和计算精度都有较大提高.     

一类免疫反应系统的Hopf分岔及控制

研究了一类病毒感染的免疫反应动力学模型的正平衡解稳定性和Hopf分岔条件,证明了正平衡解渐近稳定性和系统的渐近稳定的渐近稳定条件.给出一种基于输入-状态线性化的Hopf分岔控制方法,使得系统在给定的参数范围内是渐近稳定的.     

筛选与鲤鱼抗寒性状相关的微卫星分子标记

为了寻找鲤鱼中与抗寒性状相关的DNA序列,采用142个微卫星引物,对荷包红鲤抗寒品系、柏氏鲤及其杂交F2代中的青灰色抗寒与青灰色不抗寒个体的混合基因组DNA进行分析.经过710次微卫星分子标记检测,首次获得两个(引物HLJ578,HLJ580)与抗寒性状相关的微卫星分子标记.利用这些微卫星分子标记进一步对27个抗寒与不抗寒个体的基因组DNA进行检测,验证其准确性.结果表明:鲤鱼的抗寒性状是数量性状,且受微效多基因调控;与鲤鱼抗寒相关分子标记DNA序列的拷贝数在鲤鱼抗寒与不抗寒个体中存在差异,这些与抗寒性状相关的DNA序列的拷贝数目的多少将最终影响与抗寒性状有关的蛋白质表达量的多少.     

PD-1／PD-L共抑制信号研究进展

PD-1是主要表达在活化T细胞上的抑制性受体,与其配体PD-L(PD-L1,PD-L2)结合,可显著抑制T细胞的活化和增殖,并调节细胞因子的表达和分泌.简述PD-1/PD-L在免疫耐受、微生物感染及肿瘤免疫逃逸中的作用.