新型非接触式微液滴点样喷头的研制

微阵列芯片在基因检测等领域有着广泛的应用,制备微阵列芯片的的点样设备可分为接触式和非接触式两种,其中接触式点样需要频繁的清洗点样针头,非接触式点样设备则需要外界气泵或使用复杂的MEMS工艺制作。为了简化生物微阵列芯片制作过程中繁琐的取样、点样、清洗工作和降低点样仪器的成本,研制了一种新型的储液式微液滴点样装置,具有无需清洗、成本低、制作简便的优点。该装置采用压电陶瓷双晶片作为动力驱动,通过双晶片在液体中的振动激发出水击波,传递至喷孔处使喷孔液面发生振动,从而激发出微液滴滴落。研制的储液式微液滴点样装置可以容纳1 mL的液体试剂,可得到体积为1 nL的微液滴,可重复上万次的点样而不需清洗。以储液式微液滴点样装置为基础,进一步制作了点样仪样机。根据实验测量,储液式微液滴点样装置所产生微液滴的直径为200μm,可以满足生物微阵列芯片的制备要求。     

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。     

脂肪干细胞研究近况

脂肪干细胞是一类可以自我更新、繁殖产生更多的干细胞,进而可以分化成许多有特定功能的细胞系,具有一般干细胞的特点,可作为多种组织工程的种子细胞,有非常重要的研究和应用价值.本文着重对脂肪干细胞在诱导分化方面的最新发展进行了阐述,希望能为脂肪干细胞的进一步的研究提供理论基础.     

基于微喷技术的微胶囊制造实验研究

利用压电驱动器产生的低频振动，使微流道中的流体产生脉冲流动，通过微喷头实现微流体的数字化离散和喷射。通过控制振动的频率和微喷头的直径，可以实现微胶囊尺寸的数字化控制。利用悬浮交联微胶囊制备方法，以海藻酸钠包覆胰岛细胞进行了微胶囊制作实验，制造出了尺寸均匀的微米级尺度微胶囊。展望了基于微流体数字化的微胶囊制造技术的发展前景。     

沟槽式微热管缩径工艺研究及装置开发

分析了沟槽式微热管的缩径工艺,通过实验研究分析对比了模具挤压、钢球旋压和径向锻造这三种方法对微热管缩径质量的影响,并在此基础上设计出了符合沟槽式微热管缩径工艺要求的高效缩径装置.     

微胶囊相变储能材料研究及应用进展评述

微胶囊相变材料（Microencapsulated Phase Change Material,MCPCM）是应用微胶囊技术在固液相变材料表面包覆一层性能稳定的高分子膜而构成的具有核壳结构的复合材料。本文综述了微胶囊相变材料的制备方法、研究进展和应用领域;分析了各种制备方法的优缺点,并指出了制备微胶囊相变材料中存在的问题及今后发展方向。     

自润滑微胶囊摩擦学研究进展

综述微胶囊技术在复合材料发展中的应用状况,介绍微胶囊常用的制备方法及自润滑微胶囊在减摩抗磨领域的应用,并探讨自润滑微胶囊在聚合物基体中的摩擦机制,指出自润滑微胶囊多元化协同减摩抗磨效应在复合材料中的发展方向。     

微拉伸系统中微弹簧力学传感器的研究

研究应用于薄膜力学微拉伸测试系统的微弹簧力传感器.在单轴薄膜微拉伸系统的基础上,通过有限元模拟分析,研究以S型弹簧为结构基础的微弹簧力传感器.根据模拟结果,利用高精度线切割和UV-LIGA(Ultraviolet Lithographie GalVanoformung Abformung)技术制备出微弹簧力传感器,并在自制装置上进行标定.标定结果表明,由负胶工艺制备的自由式微弹簧力传感器有良好的线性,而且与Ansys模拟的弹性系数结果一致,为微拉伸测试系统提供良好的条件.     

微胶囊技术及其在聚合物材料中的应用

综述了近几年微胶囊技术的发展,归纳总结了微胶囊的制备方法,着重阐述了微胶囊技术在提高聚合物材料自修复、增韧、阻燃、减摩抗磨等性能方面的应用研究,并对多元复合材料体系中微胶囊及添加剂的协同效应提出了展望。     

石蜡相变微胶囊的制备及其隔热性的研究

以石蜡为囊芯，脲醛树脂为囊壳，通过原位聚合法制得了微胶囊。研究了脲醛预聚体的生成和脲醛预聚体的固化2个阶段的工艺条件对微胶囊形成的影响。显微观察微胶囊形貌完整。涂膜隔热性能测试结果表明，该种微胶囊具有明显吸热性能，可作为隔热添加剂使用。     

基于非参数变换的尿沉渣细胞图像识别方法

首先提出一种改进的局部秩变换(D-LRT)方法,通过计算图像像素的局部秩进行图像变换,根据阈值选取实现低对比度和局部模糊的尿沉渣细胞图像分割。然后提出一种局部直方图统计(LHS)方法提取细胞图像平移、旋转、光照不变特征。该方法通过高斯模糊获取不同尺度下的细胞高斯模糊图像,并利用RIUP-LBP算子获取细胞高斯模糊图像的RIUP-LBP特征图谱,基于距离变换采取由内而外的方式,分层统计细胞高斯模糊图像及其RIUP-LBP特征图谱的直方图,将所有直方图串联作为细胞图像的LHS局部特征。还同时将LHS特征结合图像的几何特征、Harris角点及灰度共生矩阵特征,从局部和全局角度构造尿沉渣细胞图像的特征向量。最后采用支持向量机(SVM)对7类典型尿沉渣细胞图像进行分类。实验结果表明:本文提出的D-LRT方法在低对比度和局部模糊的细胞图像分割中完整度明显提高,提出的LHS方法可以有效地提取7类尿沉渣细胞图像特征,7类细胞图像识别的平均准确率可达到93.0%,平均召回率可达93.2%。     

Protein localisation approaches for understanding yeast cell wall biogenesis

Yeast cells are surrounded by the cell wall, a rigid but dynamic structure that is essential for their viability. The complexity and functionality of this structure suggest that a high number of proteins must be involved in the biogenesis of the cell wall architecture and, as a consequence, in the maintenance of cell integrity. Among them, a high percentage is assumed to be located at the cell surface, mostly as structural or enzymatic components of the cell wall. Therefore, the presence of a protein in the cell wall is suggestive of its cell wall-related function. Different techniques can be used to specifically detect the cell wall localisation of a given protein or to identify cell wall proteins in large-scale analyses. These include the detection of proteins in whole cells or specific cell wall fractions by immunological, biochemical, microscopic, or genetic approaches, as well as the emerging proteomic technology. The advantages, limitations, and usefulness of these techniques are discussed and illustrated with some examples.     

Live cell tracking based on cellular state recognition from microscopic images

The analysis of cell motion is an essential process in fundamental medical studies because most active cellular functions involve motion. In this paper, a computer-assisted motion analysis system is proposed for cell tracking. In the proposed tracking process, unlike in conventional tracking methods, cellular states referring to the cellular life cycle are defined and appropriate strategies are adopted for cells at different states. The use of cellular state recognition allows detection of possible cell division and hence can improve the robustness of cell tracking. Experimental results show that cells can be successfully segmented and tracked over a long period of time, and the proposed system is found to be as accurate as manual tracking. Various quantitative analyses and visualizations are used to represent cell motion, which demonstrates the usefulness of the proposed system in the study of cell dynamics.     

Atomic force microscopy and cells: Indentation profiles around the AFM tip,cell shape changes,and other examples of experimental factors affecting modeling

We use atomic force microscopy in conjunction with a fluorescence microscope capable of optical sectioning to acquire images of white blood cells while force is applied with the AFM tip. The indentation profile within the cell is compared to the profile of the AFM tip: examples are shown for indentations at the center of the cell which are reasonable matches to the tip profile, and an additional example is shown for an indentation that is on the tilted side of a highly rounded cell and that differs from the tip shape. We also demonstrate that the AFM tip can interact with internal cell structures, we show that the contact area between the cell and the substrate can increase under applied pressure, that the main body of the cell can fuse with the extended lamellipodium, and that the cell can be displaced laterally by the AFM tip. The features illustrated here are relevant to the interpretation of indentation experiments that measure cell elasticity properties, as is discussed briefly. Microsc. Res. Tech. 78:626–632, 2015. © 2015 Wiley Periodicals, Inc.     

人工骨体外灌注中微管道内细胞及细胞悬液两相流数值研究

为了预知体外细胞悬液灌注中细胞浓度的分布和可能沉积的部位,以指导人工骨管道结构设计及灌注技术, 有必要进行微管道系统中细胞输运数值分析。研究了a,b,c三种微管道中细胞浓度分布、细胞和细胞悬液速度场及压力分布,并分析了微管道系统中细胞可能沉积的部位。研究表明,在该微管系统的模拟哈佛氏管和佛克曼管交叉处及距离下管壁约0．3r(半径)处细胞浓度较高,三种管道系统内细胞浓度分布范围分别集中在0．42％- 5．56％,0,36％～2．23％,1．94％～2．06％,离管壁一定距离处可能存在细胞相速度大于液相的过渡区域,该过渡区域内由于细胞扩散作用和贴壁生物特性将部分沉积于管壁,过渡区域外的主流区细胞相速度小于液相速度,但大部分细胞将被液相带走。     

The choice of cell face velocities in the three dimensional incompressible flow calculations on nonorthogonal grids

The effect of choice of cell face velocities on the solution behaviours in the three dimensional incompressible flow calculations on nonorthogonal grids are investigated in detail. The calculation schemes based on the curvilinear contravariant and covariant cell face velocities are developed and are applied to the test problems to assess their relative performances. It is observed that the accuracy of the converged solution is not affected by the different choice of cell face velocities. However, the scheme based on the covariant cell face velocities shows better convergence behaviours when the numerical grids are strongly nonorthogonal.     

基于异构Agent系统的虚拟制造单元

虚拟制造单元是虚拟制造系统的一个重要组成部分。本文分析了Agent系统特点 ,提出了一种基于异构A gent系统的虚拟制造单元 ,并建立了审慎式Agent和反应式Agent并存的系统体系结构。根据系统分层和异构的特点 ,定义了Agent的结构模型及其运行模式。采用过程调用模式与消息模式相结合的方式解决了各Agent之间的通信问题。根据所提出的观点并利用相关的开发工具 ,初步实现了一个虚拟制造单元     

Effects of defects on in-plane properties of periodic metal honeycombs

The effects of missing or fractured cell walls on in-plane effective elastic stiffness and initial yield strength of square and triangular cell metal honeycombs are investigated using finite element analysis. Due to the change of localized deformation mode, the in-plane properties of defected honeycombs can differ significantly from those of intact metal honeycombs, depending on cell type and stress state. First, the effect of the size of a statistical volume element of honeycomb cells with randomly removed cell walls is explored by using different numbers of cells with 5% of walls removed, subject to periodic boundary conditions. The size of a representative volume element (statistically homogeneous) is determined for each considered in-plane property. Next, the effective in-plane properties of square cell and triangular cell honeycombs are, respectively, calculated as a function of increasing number density of randomly removed cell walls. Finally, the sensitivities of axial compressive effective properties of these honeycombs to missing cell walls are compared with that of a previously analyzed hexagonal cell honeycomb. The results indicate that some in-plane properties sharply diminish with defect density, while others exhibit more gradual decay. In compression, the effective elastic stiffness and initial yield strength of triangular cell honeycombs are least sensitive to defects among those considered.     

Infra-red microspectroscopy of hydrated biological systems: design and construction of a new cell with atmospheric control for the study of plant cell walls

A new hydration cell has been constructed that allows wet biological samples, or samples of controlled moisture content, to be analysed in situ using infra-red microspectroscopy. The cell has been used to show that there are minor spectral changes associated with the hydration of pectin and tomato pericarp cell walls and slightly more significant changes in onion and carrot epidermal walls. The cell was also used to show that molecular orientations of polymers, previously observed in dry cell walls, were also to be seen in hydrated walls. For cell walls of onion and carrot epidermis, it was shown that the orientations of cell wall polymers are not affected by hydration. Furthermore, the polymer orientations in cell walls of fully elongated onion epidermal cells are different from those of elongating carrot epidermis. By using the hydration cell, it is now possible to investigate both fresh samples and wet systems routinely. The applications of this to the study of biological materials with infra-red microspectroscopy are discussed.     

An improved technique for the freeze-fracture of cell cultures grown as monolayers

An improved and rapid procedure for the freeze-fracture of cell cultures grown as monolayers is described. No additional equipment than normally used for freeze-fracturing is necessary and cell culture conditions are as usual on plastic dishes. Cells are grown on a plastic foil membrane so that they can be viewed with a light microscope. If necessary, while viewing with a binocular microscope, specimen holders are glued to the foil membrane over selected areas of the culture. The specimen holders with the attached cell culture are dissected out and processed for freeze-fracturing in a BIOETH 2005. Fracture planes occur along the cell surface as well as through entire cells. Analysis of corresponding fracture faces is possible.