Bcl-2、Bax、Fas、FasL、穿孔素和粒酶B在移植肾急性排斥中的共同表达和意义

目的 检测Bcl-2、Bax、Fas、FasL、穿孔素和粒酶B 在移植肾急性排斥时的表达水平,探讨其在急性排斥中的作用及可能的分子机制.方法 选取30例移植肾穿刺活检标本及18例正常供肾组织为研究对象,采用免疫组化方法检测Bcl-2、Bax、Fas、FasL、穿孔素和粒酶B 的表达情况.结果 ①根据Banff97病理诊断标准,急性排斥标本30例,其中ⅠA 12例,ⅠB 11例,ⅡA 5例,ⅡB 2例;②所有组织中均可发现细胞凋亡现象,急性排斥标本中更为明显;③Bcl-2在急性排斥标本中的表达水平低于正常组织(P＜0.05),与急性排斥的病理变化呈负相关(P＜0.05);Bax在两组的表达水平无差别(P＞0.05);Fas、FasL、穿孔素和粒酶B在急性排斥组中的表达水平均高于对照组,并与急性排斥的病理变化呈正相关,以FasL和粒酶B 最为明显(P＜0.01).结论 ①Bcl-2在肾小管上皮细胞的表达减少提示急性排斥反应的发生;②Bax对于预测急性排斥反应的意义不大;③Bcl-2、Fas、FasL、穿孔素和粒酶B的表达变化均与急性排斥反应密切相关,尤以FasL和粒酶B明显,可作为监测移植肾形态学变化、功能状态以及判断预后的重要指标.     

大鼠不同分离纯化方法对胰岛细胞丢失的影响

目的探讨提高大鼠胰岛细胞产量和纯度的最佳分离纯化方法。方法40只大鼠分为4组,每组10只。A组:Hanks液灌注 胶原酶V消化 Ficoll400梯度纯化;B组:组织剪碎研磨 筛网过滤;C组:胶原酶V灌注 Ficoll400梯度纯化;D组:胶原酶V灌注 筛网过滤。对用四种不同方法分离纯化的结果进行比较。结果完全随机设计的方差分析显示,A、B、C、D组收获量及纯度比较均有显著性差异(P<0.05);组间多重比较显示,A组收获量均高于B、D组(P<0.05),与C组比较差异无统计学意义(P>0.05);A组纯度与其他组比较均无显著性差异(P>0.05)。结论用胶原酶V或Hanks液灌注,Ficoll400梯度纯化法所收获胰岛细胞的产量和纯度较高,而且价格低廉,是一种较理想的胰岛细胞分离纯化方法。     

Solute clearance effect of citrate anticoagulation hemodialysate for hemodialysis in patients with high risk of bleeding

Objective To study the solute clearance effect of the new concentrated anticoagulation hemodiaiysate of citrate for hemodialysis in patients with high risk of bleeding. Methods Forty-two kidney failure patients with high risk of bleeding were divided into two groups (Group A and Group B) according to their hemodialysis manners. Patients in Group A were hemodialyzed with bicarbonate hemodialysate with low-molecular-weight heparin (dalteparin) anticoognlation and those in Group B with the new citrate antieoagnlation hemodialysate prepared in our hospital without any other anticoagulant. Blood urea nitrogen (BUN) and creatinine (Cr) concentrations were measured before and after dialysis, and Kt/V and urea reduction rate (URR) were calculated. In addition, activated clotting time (ACT) and ionized calcium (iCa2 ) concentration were also measured at the arterial and venous ends. Results ACT was extended and iCa2 concentration decreased significantly at the venous end compared with those at the arterial end in Group B (P<0.01). BUN and Cr concentrations were markedly decreased after dialysis compared with those before dialysis in both groups (P<0.01), and no significant difference in solute clearance effect, as indicated by Kt/V and URR, was observed between Group A and Group B (P>0.05). Conclusion The solute clearance effect of the new concentrated anticoagnlation hemodialysate of citrate is excellent during hemodiaiysis in kidney failure patients with high risk of bleeding.     

蚌埠闸减压井失效原因分析

蚌埠闸19口减压井建于20世纪60年代初,建成运行不久即淤堵严重。虽经数次清淤,但清后复淤,收效甚微,承压水位较工程运行初期逐年呈上升趋势。该文从井的外淤和内淤两个方面初步分析了减压井失效的原因,指出了原减压井设计上的缺陷。对今后减压井的设计和施工的改进可提供参考。     

基于PMV-PPD和EQT指标的乘员舱热舒适性研究

利用STAR-CCM+软件对某型轿车的乘员舱进行数值模拟,计算中考虑到太阳辐射和壁面间辐射的影响,设定太阳的方位角和高度角均为90?,通过仿真得到舱内速度场、温度场以及人体表面温度的分布;通过建立PMV-PPD指标评价乘员舱的整体热舒适性,再利用EQT指标评价舱内乘员的局部热舒适性,利用多指标评价体系较为全面地评价乘员舱内的热舒适状况。     

Hydrodynamics study of a BCF mode bioinspired robotic-fish underwater vehicle using Lighthill’s slender body model

This paper investigates the hydrodynamic characteristics of the rectilinear motion of a robotic fish underwater vehicle. This 2-joint, 3-link multibody vehicle model is biologically inspired by a body caudal fin carangiform fish propulsion mechanism. Navier–Stokes equations are used to compute the unsteady flow fields generated due to the interaction between the vehicle and the surrounding incompressible and Newtonian fluid (water) environment. The NACA 0014 airfoil aerodynamic profile has been designed to boost the swimming efficiency by reducing drag as the vehicle undergoes an undulatory/oscillatory motion. Using the Lighthill slender body model, a traveling wave mathematical function is defined to undulate the robotic fish posterior (caudal) region while the motion tracking is carried out by dynamic meshing technique. The results obtained show that though the net lift force approaches to zero, the net thrust or negative drag coefficient maintains a finite value dependent on kinematic parameters like tail beat frequency (TBF) and amplitude span (AS) at a given propulsive wavelength and the forward velocity of the vehicle. The results reveal the effects of TBF and AS on the coefficient of drag friction and the thrust force. Drag coefficients obtained from the simulations are compared and validated with the experimental results. The hydrodynamic results are found to be similar to the kinematic study results and suggest that TBF and AS play the most effective roles in the bioinspired propulsion technique. Relation of these parameters with propelling thrust force and forward velocity is also in conjunction over a given range of TBF and AS values.     

基于小波神经网络的路面破损识别

结合图象处理、模式识别等先进技术开发路面破损自动检测系统已经成为本领域的研究热点[1-5]。本主要研究了小波神经网络在路面破损识别中的应用，并与传统的BP神经网络作了对比。试验结果表明．在相同的训练样本情况下，小波神经网络的精度高于BP神经网络一为开发更为高效的路面破损自动检测系统提供新的思路。     

基于混合密度因子的路面破损自动识别研究

路面破损分类成为限制路面破损自动检测的普及和发展的重要因素．本文在已提出的破损密度因子算法的基础上,进一步设计出了混合密度因子,得到一种基于图像子块分布特征的路面破损识别算法．通过仿真,验证了其对常见的5种路面破损类型进行分类的可行性,并选择了另外一种路面破损分类算法来进行神经网络仿真对比．神经网络的训练样本是两组,测试样本也是两组,进行了四次仿真对比．四次仿真结果都显示混合密度因子算法有很高的识别率．     

三维非赫兹滚动接触理论在 轮轨滚动接触中的应用* ——TPLR 的编制及应用

应用Kalker 的三维弹性体非赫弱滚动接触理论, 将运动于直线轨道上的单轮对蠕滑率 ?力关系, 建立在TPLR (非赫兹轮轨蠕滑力数表) 中。分析了不同正压力所对应的蠕 滑力值以及用表中的数值修正的蠕滑力值的精度。简单介绍了该表的使用方法。      

基于DEA法的我国水运建设绩效评价

为推动我国水路交通运输的发展,针对资源重复投入、分配不均、基础设施重复建设、共享利用率不高等问题,采用数据包络分析（DEA）方法,对2008年我国12个省（区）的水运建设投入产出值进行评价,并对各省提出将有限的水运建设资源进行合理有效的分配和投放,从而获得投入产出效益最大化的建议。