一种新的提取脂肪间充质干细胞的方法及对提取细胞的分离、培养及鉴定

目的：探讨建立一种新的从膨胀液中提取脂肪间充质干细胞（ADSCs）的分离方法。方法：收集含有脂肪间充质干细胞的膨胀液,然后从膨胀液中分离出脂肪间充质干细胞并进行体外培养,观察培养间充质干细胞生长状态,流式细胞术检测间充质干细胞干性标记物,细胞生长曲线比较新方法与运用传统方法分离脂肪间充质干细胞的增殖活性,多向诱导分化鉴定其向成骨,成软骨及成脂方向分化的能力。结果：成功建立了一种新的从膨胀液中提取脂肪间充质干细胞的分离方法;分离自膨胀液的间充质干细胞数量虽然低于与等体积脂肪组织来源的间充质干细胞,但细胞生长曲线分析结果表明其增殖速度快,生长至第8天时,密度基本等同于脂肪组织来源间充质干细胞。间充质干细胞表面分子标记物CD73,CD90,CD105,CD45,CD34,CD11b,CD19,HLA—DR表达测定结果显示正常,阳性细胞率与脂肪组织来源的干细胞相近。多向诱导分化结果显示从膨胀液中分离的脂肪间充质干细胞可以向成脂、成骨和成软骨三向分化。结论：新方法分离的细胞确为脂肪间充质干细胞,符合国际干细胞协会规定的定义标准。     

开孔型橡塑多孔材料的应力-应变行为

研究了拉伸应力对开孔型橡胶一塑料多孔材料形态结构和力学性能的影响。结果表明：拉伸应力的增加使橡塑多孔材料产生了形变，导致了气泡孔孔径、透水率的增大。不同定伸长率试样的回缩率是有差异的，定伸长愈大，试样的回缩形变就愈大；回缩形变随时间的变化主要发生在拉伸试样恢复期的初期，30d后试样的形变基本稳定。     

DRYING WOOD: A REVIEW - PART I

ABSTRACT

This paper reviews the technology of wood drying and recent developments in the field. The importance of drying is reviewed first. Then the fundamentals of wood properties as they relate to drying are discussed, including how water is held in wood, how it moves through wood, and how drying stresses that lead to drying defects develop. Traditional drying technology for lumber, veneer, and heavy timbers is then presented. With this background, the discussion moves to recent developments in drying technology that have been implemented commercially, such as high-temperature drying, low-temperature drying, continuously rising temperature drying, vacuum drying, and advances in process control. Finally, a discussion is presented on drying technology of the future. This topic describes processes that offer potential improvements in drying technology, but are still in the research and development stage.     

The cytotoxicity evaluation of magnetic iron oxide nanoparticles on human aortic endothelial cells

One major obstacle for successful application of nanoparticles in medicine is its potential nanotoxicity on the environment and human health. In this study, we evaluated the cytotoxicity effect of dimercaptosuccinic acid-coated iron oxide (DMSA-Fe₂O₃) using cultured human aortic endothelial cells (HAECs). Our results showed that DMSA-Fe₂O₃ in the culture medium could be absorbed into HAECs, and dispersed in the cytoplasm. The cytotoxicity effect of DMSA-Fe₂O₃ on HAECs was dose-dependent, and the concentrations no more than 0.02 mg/ml had little toxic effect which were revealed by tetrazolium dye assay. Meanwhile, the cell injury biomarker, lactate dehydrogenase, was not significantly higher than that from control cells (without DMSA-Fe₂O₃). However, the endocrine function for endothelin-1 and prostacyclin I-2, as well as the urea transporter function, was altered even without obvious evidence of cell injury in this context. We also showed by real-time PCR analysis that DMSA-Fe₂O₃ exposure resulted in differential effects on the expressions of pro- and anti-apoptosis genes of HAECs. Meanwhile, it was noted that DMSA-Fe₂O₃ exposure could activate the expression of genes related to oxidative stress and adhesion molecules, which suggested that inflammatory response might be evoked. Moreover, we demonstrated by in vitro endothelial tube formation that even a small amount of DMSA-Fe₂O₃ (0.01 and 0.02 mg/ml) could inhibit angiogenesis by the HAECs. Altogether, these results indicate that DMSA-Fe₂O₃ have some cytotoxicity that may cause side effects on normal endothelial cells.     

成体干细胞可塑性研究进展

成体干细胞是存在于发育成熟机体组织中的具有自我更新和分化潜能的细胞。已证实,骨髓、神经、肌肉、脂肪等多种组织中的干细胞具有多向分化的潜能。这些干细胞可以打破胚层界限,横向分化为其他组织的成熟细胞,这种性质称为干细胞的可塑性,是成体干细胞应用于临床的理论基础,具有广阔的临床应用前景。然而对干细胞可塑性的机制仍存在较大的争议。本文对近几年此方面的研究进展作一综述。     

非灌流法分离大鼠肝星形细胞及其鉴定

目的采用非灌流法分离大鼠肝星形细胞(Hepatic stellate cell,HSC),并进行鉴定。方法采用非灌流法结合酶消化法分离大鼠肝脏细胞,密度梯度离心进一步分离HSC,油红染色检测HSC胞质中的脂滴,免疫组化法检测细胞中α-平滑肌肌动蛋白(α-Smooth muscle actin,α-SMA)、结蛋白(Desmin)及神经胶质酸性蛋白(Glial fibrillary acidic protein,GFAP)的表达。结果非灌流法结合酶消化法可成功分离大鼠HSC;密度梯度离心纯化的HSC经油红染色,细胞核周围可见红色脂滴;该细胞中α-SMA、结蛋白及GFAP的免疫组化染色结果均呈阳性,细胞着色率可达90%以上。结论成功建立了大鼠HSC的非灌流分离模式,所获得的HSC纯度较高,该方法稳定简便,具有一定的推广应用价值。     

纳米级金红石相二氧化钛晶胞数原子数和晶面原子数的计算与研究

以矿物晶体结构、晶体化学理论为基础，通过对纳米级金红石相二氧化钛颗粒的晶胞数、原子数及平行（001）面的表面原子数的计算，讨论了它们与纳米级金红石二氧化钛颗粒尺度大小的相关规律，并结合纳米微粒的特性对其进行了简要分析。     

RuAg/TiO2-C催化剂的制备及对甲醇的电催化氧化性能

采用改性溶胶凝胶法和水热合成法制备了掺C多孔纳米TiO2,并以其为载体制备了一种RuAg/TiO2-C甲醇催化剂。采用X射线衍射（XRD）、透射电镜（TEM）、X射线能谱（EDS）和X射线光电子能谱（XPS）等对催化剂进行了表征,测定了其对甲醇的电催化氧化性能。实验结果表明,RuAg的负载和C的掺杂能提高TiO2对甲醇的电催化性能,RuAg/TiO2-C对甲醇电催化的循环伏安曲线中未见甲醇氧化中间产物的氧化峰,0.544 V处有一个较大的甲醇氧化峰,其峰电流密度5.8 mA/cm2,RuAg/TiO2-C比商用PtRu/C催化剂具有更高的催化活性和抗毒性,RuAg合金的负载以及RuAg合金与掺C多孔纳米TiO2载体之间较强的相互作用是其对甲醇催化性能提高的主要因素。     

平板状固体氧化物燃料电池电化学特性Simlink建模与仿真

在分析平板状固体氧化物燃料电池电化学特性的基础上,建立了Simlink仿真模型,探讨了工作温度和燃料中水蒸气含量对燃料电池理想电势和有效电势的影响。仿真结果表明,低电流密度下,温度的升高会导致有效电势的降低;高电流密度下,有效电势会随着温度升高而增加。水蒸气含量越低,燃料电池的理想电势和有效电势越高。     

Swelling effect of a polymer electrolyte membrane on the development of a semi-empirical cell voltage model

We developed a new cell voltage model which depends on the current density response of the proton exchange membrane fuel cell (PEMFC). The proposed model focuses on the conductivity of a PEMFC fuel cell. The model for conductivity of a polymer electrolyte membrane, Nafion, uses the thermodynamic function to represent water activity. We observed membrane conductivity by monitoring the chemical potential of the swelling of the hydrogel. The swelling equilibrium of the ionized hydrogel is governed by the free energy of mixing, the free energy of elasticity, and the concentration of counterions with fixed charges on the gel network. A cell voltage equation with reasonable boundary conditions, including the swelling effect, which plays a major role in determining the cell voltage of a PEMFC, was newly developed.