转化生长因子-β1对大鼠腹膜间皮细胞炎症因子及细胞外基质表达的影响

目的 研究转化生长因子-β1（TGF-β1）对大鼠腹膜间皮细胞炎症因子表达和细胞外基质（ECM）积聚的影响。方法 体外培养SD 大鼠原代腹膜间皮细胞,静止24h 后,采用RT-PCR 检测TGF-β1（10ng/ml）刺激后0、3、6、12、24、48h 单核细胞趋化蛋白-1（MCP-1）、白介素-6（IL-6）、Ⅰ型胶原（CollagenⅠ）、纤溶酶原激活物抑制物-1（PAI-1）mRNA 的表达情况;Western blot 检测TGF-β1（10ng/ml）刺激后0、4、12、24、48h CollagenⅠ和PAI-1 表达情况;ELISA 法检测MCP-1 和IL-6 表达情况。结果 TGF-β1处理6h 后MCP-1、IL-6 和PAI-1mRNA 即开始逐渐升高,与0h 组的差异均有统计学意义（均P＜0.05）,24h 后显著升高（均P＜0.01）;TGF-β1 处理12h 后CollagenⅠmRNA 表达开始明显升高,与0h 比较差异有统计学意义（P＜0.05）,24h 后有显著升高（P＜0.01）;TGF-β1 处理4h 后IL-6 表达水平升高（P＜0.05）,24h 后显著升高（P＜0.01）;处理12h 后MCP-1 和PAI-1 表达水平较0h 明显升高（P＜0.05）,处理24h 后CollagenⅠ表达水平显著升高（P＜0.05）;TGF-β1 显著增加MCP-1、IL-6、CollagenⅠ、PAI-1 及其mRNA 的表达上调。结论 TGF-β1可能通过诱导大鼠腹膜间皮细胞炎症因子上调表达和ECM积聚导致腹膜纤维化。     

硒对肾间质纤维化大鼠肾组织结缔组织生长因子表达及肾小管上皮细胞表型转化的影响

目的探讨硒对肾间质纤维化大鼠肾组织结缔组织生长因子（CTGF）表达及肾小管上皮细胞表型转化的影响。方法以单侧输尿管结扎致肾间质纤维化大鼠模型。将54只SD大鼠随机分为假手术组（A组）、单侧输尿管梗阻（UUO）组（B组）、U-UO+硒组（C组）,每组18只。C组给予亚硒酸钠0.2mg/（kg·d）灌胃。A、B组给予同等剂量0.9%氯化钠溶液灌胃。术后第7、14、21天各组随机处死6只大鼠,肾组织行HE、Masson染色评定肾间质纤维化程度,免疫组织化学半定量法检测CTGF和α-平滑肌肌动蛋白（α- SMA）的表达。Western印迹法检测肾组织CTGF蛋白表达。化学比色法检测肾组织氧化指标谷胱甘肽过氧化物酶（GSH- Px）、超氧化物歧化酶（SOD）、丙二醛（MDA）的表达水平。结果术后各时点C组肾间质纤维化程度较B组明显减轻（P＜0.05）,肾组织CTGF和α- SMA的表达强度明显低于B组（P＜0.05或0.01）、GSH- Px和SOD水平明显高于B组（P＜0.05）,MDA含量明显低于B组（P＜0.05）。B组肾组织中CTGF、a- SMA表达量之间呈正相关（P＜0.05）,CTGF和a- SMA表达量与肾间质纤维化病变程度呈正相关（P＜0.05）。结论硒可以减轻UUO模型大鼠肾间质纤维化程度,其机制可能与硒的抗氧化作用、下调肾组织CTGF的表达、抑制肾小管上皮细胞－肌成纤维细胞转分化有关。     

Effect of an autapse on the firing pattern transition in a bursting neuron

On the basis of the Hindmarsh–Rose (HR) neuron model, the dynamics of electrical activity and the transition of firing patterns induced by three types of autapses have been investigated in detail. The dynamic effect of an autapse is detected by imposing a feedback term with a specific time-delay and autaptic intensity. We found that the delayed autaptic feedback connection switches the electrical activities of the HR neuron among quiescent, periodic and chaotic firing patterns. In the case of an electrical autapse, the transition from a periodic to a chaotic state occurs depending on the specific autaptic intensity and the time-delay. The excitatory chemical autapse plays a positive role in generating and enhancing the chaotic state. A time delay could decrease and suppress the chaotic state in the case of inhibitory chemical self-connections with a proper autaptic intensity. The bifurcation diagram vs. time-delay and autaptic intensity has been extensively studied, and the time series of membrane potentials and the distribution of information entropy have also been calculated to confirm the bifurcation analysis.     

肝豆状核变性患者的肾脏病变特点及长期使用青霉胺的影响研究

目的 探讨肝豆状核变性患者肾脏病变的特点及长期使用青霉胺治疗对其产生的可能影响。方法 选取70 例临床 确诊为肝豆状核变性患者作为观察组,根据临床表型和使用青霉胺时间分为肝脏型组、肝脑混合型组、脑型组及使用青霉胺＜5年组、5～10 年组、＞10 年组,检测并比较各组患者尿总蛋白（TG）、低分子量蛋白（LMW）、高分子量蛋白（HMW）、β2微球蛋白（β2-MG）、β－N-乙酰氨基葡萄糖苷酶（NAG）、白蛋白（ALG）及血肌酐（Scr）等肾脏病变相关指标;另选择无血缘关系且血铜蓝蛋白及铜氧化酶等铜代谢检查均正常的健康志愿者70 例作为对照组,检测上述指标并与观察组对照。结果 观察组的肾脏病变相关指标显著高于对照组;不同临床表型的患者各项指标间无统计学差异;随着服用青霉胺时间的延长,患者尿液中β2-MG、LMW百分比、NAG、TG水平逐渐降低,HMW 百分比、ALG水平逐渐升高,TG 呈现逐渐降低的趋势,Scr 保持不变。结论 肝豆状核变性患者肾小球和肾小管的功能均有明显的损伤;肾脏病变在不同临床表型之间无统计学差异,长期使用青霉胺治疗对肾小球的功能有一定的损伤。     

Effect of A-site cation substitution on magnetic transition temperature of (LaCa) MnO3

The ferromagnetic transition temperatures have been measured on two bathes of perovskite manganese oxides such as (La_1-x R _x )_2/3Ca_1/3MnO₃(R=Ce, Pr, Nd, etc.) and La_2/3(Ca_1-y Cd _y )_1/3MnO₃. It is found that the (La_1-x R _x )_2/3Ca_1/3MnO₃ samples have obviously different Curie temperatureT _C although their (r_A) (the average A-site cation radius) are almost identical, and theT _C in the system of (La_1-x R _x )_2/3Ca_1/3MnO₃(R=Ce, Pr, Nd, etc.) and La_2/3(Ca_1-y Cd _y )_1/3MnO₃. It is found that the (La_1-x R _x )_2/3Ca_1/3MnO₃ compounds increases with increasingy although (r_A) decreases slightly. It is suggested that the Curie temperature should be influenced by the average local A-site magnetic moment in the ferromagnetic perovskite manganite system. Project supported by the National Natural Science Foundation of China (Grant No. 19504012) and the Chinese Academy of Sciences.     

Propagation of torsional waves in tubular bones

By considering the material inhomogeneity and anisotropy of osseous tissues, the propagation of torsional waves in tubular bones has been studied in this paper. An exact closed form solution is presented. The electric and magnetic fields induced by the travelling torsional waves in tubular bones are also derived by accounting for the piezoelectricity of osseous material. Making use of the derived analytical solution, and the experimentally determined constants for osseous tissues, numerical values of the phase velocities and attenuation coefficients are calculated for different frequencies in the ultrasonic range. Further, the effects of material damping and inhomogeneity on the attenuation and phase velocities of the waves are examined.     

Optimization of bifunctional catalysts in tubular reactors

A number of chemical reactions of industrial importance, especially reforming reactions, are most effectively promoted by bifunctional catalysts in tubular reactors. For the determination of the optimal catalyst blend, a mathematical model for a general first-order kinetic reaction scheme is developed. The introduction of state-space definitions leads to a model described by a bilinear system. Based on that system and a suitably defined performance index, necessary conditions for the optimal catalyst blend are derived by means of the maximum principle. Special attention is directed to the singular solution of the optimization problem.This paper was presented at the 14th Joint Automatic Control Conference, Columbus, Ohio, 1973.     

Effect of the type of state of stress on the characteristics of the mechanical glass transition process in polymers

The effect of the type of state of stress on the activation energy and relaxation time is investigated with reference to the mechanical glass transition (softening) process in polymers. An expression relating the mechanical glass transition temperature with the structural glass transition temperature, the mean stress, and the stress intensity is obtained for isotropic homogeneous polymers. Experimental data obtained for polymethyl methacrylate in uniaxial tension and compression, pure bending, and shear are presented.All-Union Scientific Research Institute of Aviation Materials, Moscow. Translated from Mekhanika Polimerov, No. 2, pp. 195–199, March–April, 1971.     

管状曲面在曲线论中的应用

研究了围绕曲线的管状曲面上的曲率线,渐近线与测地线,给出它们的方程,揭示了这些曲线与Bertrand曲线或Mannheim曲线之间的关系,采用新的方法给出一条曲线是Bertrand曲线或Mannheim曲线的充要条件的另一种证明以及Mannheim侣线的曲率与挠率之间的关系．     

Vibration of a tubular bone in axial planes

By considering the material nonhomogeneity as well as the dissipative material behaviour of osseous tissues, the paper is devoted to a study of a vibrating tubular bone specimen. In conformity to recent experimental observations, nonlinear variation of the elastic moduli of bone tissues with volume density, has been paid due attention. Computational results indicate that while linear variation of the material parameters with volume density of bone tissues does not bring about any appreciable change in frequency of the bone specimen, nonlinear variation alters the frequency spectrum to a considerable extent.