Circulation times of hepatocellular carcinoma cells by in vivo flow cytometry

Hepatocellular carcinoma （HCC） may metastasize to many organs. The survival rate is almost zero for metastatic HCC patients. Molecular mechanisms of HCC metastasis need to be understood better and new therapies must be developed. We have developed the ＂in vivo microscopy＂ to study the mechanisms that govern liver tumor cells spreading through the microenvironment in vivo. A recently developed ＂in vivo flow cytometer＂ combined with real-time confocal fluorescence imaging is used to assess spreading and the circulation kinetics of liver tumor cells. We measure the depletion kinetics of two related human HCC cell lines, high-metastatic HCCLM3 cells and low-metastatic HepG2 cells, which are from the same origin and obtained by repetitive screenings in mice. More than 60% of the HCCLM3 cells are depleted within the first hour. Interestingly, the low-metastatic HepG2 cells possess noticeably slower depletion kinetics. In comparison, less than 40% of the HepG2 cells are depleted within the first hour. The differences in depletion kinetics might provide insights into early metastasis processes.     

Synthesis and Characterization of TiO2 Doped ZnO Microtubes

以氯化锌和硫酸钛为原料,通过湿化学法成功制备了钛掺杂氧化锌微米管. 以粉末X射线衍射仪、场发射扫描电子显微镜、光致发光系统对样品进行了表征. 结果表明,未经掺杂的氧化锌微管具有良好的六方中空结构. 在TiO₂/ZnO比率小于5%时,钛掺杂和未掺杂氧化锌管具有相近的尺度,外表光滑,近于圆柱形. 当TiO₂/ZnO比率大于5%时,生成一种由ZnO, Ti₃O₅和TiO组成的多相混合物. 钛掺杂氧化锌在光催化降解甲基橙溶液效果明显.     

Respiratory noise correction using phase information

Respiratory noise is a confounding factor in functional magnetic resonance imaging (MRI) data analysis. A novel method called Respiratory noise Correction using Phase information is proposed to retrospectively correct for the respiratory noise in functional MRI (fMRI) time series. It is demonstrated that the respiratory movement and the phase of functional MRI images are highly correlated in time. The signal fluctuation due to respiratory movements can be effectively estimated from the phase variation and removed from the functional MRI time series using a Wiener filtering technique. In our experiments, this new method is compared with RETROICOR, which requires recording respiration signal simultaneously in an fMRI experiment. The two techniques show comparable performance with respect to the respiratory noise correction for fMRI time series. However, this technique is more advantageous because there is no need for monitoring the subjects’ respiration or changing functional MRI protocols. This technique is also potentially useful for correcting respiratory noise from abnormal breathing or when the respiration is not periodic.     

A cell functional minimization scheme for parabolic problem

We are interested in a robust and accurate finite volume scheme for 2-D parabolic problems derived from the cell functional minimization approach. The scheme has a local stencil, is locally conservative, treats discontinuity rigorously and leads to a symmetric positive definite linear system. Since the scheme has both cell centered unknowns and cell edge unknowns, the computational cost is an issue and a parallel algorithm is then suggested based on nonoverlapping domain decomposition approach. The interface condition is of the Dirichlet–Robin type and has a parameter λ. By choosing this parameter properly, the convergence of the iteration process could be sped up. Numerical results for linear and nonlinear problems demonstrate the good performance of the cell functional minimization scheme and its parallel version on distorted meshes.     

ASTER和Landsat-7 ETM+两种多光谱传感器影像的交互对比

20世纪末以来,多种新型传感器的升空使得不同传感器之间的互为比较成为一个新的研究热点,但是ASTER和Landsat-7 ETM+传感器多光谱数据之间的全面对比在国内外尚未报道,为此,该文对AS-TER和Lanolsat-7 ETM+传感器影像数据进行了对比互补研究.文章从传感器的轨道特征、扫描方式、光谱范围和光谱响应特征等方面对二者进行机理上的分析和对比.在此基础上,基于3对同步过空的影像对和大面积同质感兴趣区的实验和统计分析,研究了ASTER与Landsat-7 ETM+传感器在可见光-近红外、短波红外各对应光谱波段之间的关系,提出了各对应波段相互转换的关系方程式,验证了所求的关系方程的有效性.最后对两种传感器影像对应光谱波段的差异进行了分析.验证结果表明,所求的关系转换方程具有较高的精度.     

便携式多源光谱融合水质分析仪的研制

采用光谱信息融合理论,研制了一种新型便携式多参数水质分析仪,自行设计了仪器的分析方法、硬件结构、内部工作原理及软件功能.可作为一种无须化学试剂、体积小、快速、易于野外现场作业的绿色水质检测工具.通过对少量水质样品的光谱测量分析,快速检测了总有机碳(TOC)、化学需氧最(COD)等6类水质有机污染物指标.实际测量结果表明,本仪器采用的基于多源光谱信息融合的水质分析方法测量精度显著优于目前市场上普遍采用的常规紫外吸收光谱法.     

红外辐射在水雾中衰减计算的修正方法研究

水雾系统对红外光谱有着强烈的衰减作用,因此在军事目标的各种制导对抗中被予以高度的关注。以Mie散射理论为基础,分析了粒子对红外光谱前向散射的聚集特性,定义了近前向散射比,并确定了在应用朗伯比尔定律时需修正的粒子尺度和散射半角的范围。通过大量计算发现,单独将粒子尺度和散射半角的乘积作为独立变量计算的视消光系数不够精确。在中远红外波段,前向散射附近的小角度内散射强度积分与粒子尺度和散射角都成正比,若红外波长为定值,则与粒子半径成正比。最后根据前向散射规律给出了两个不单独以x.θ为变量的经验计算公式,使得对水雾消光的修正计算更加简便精确。     

Study on the Structure of TiO2 Thin Film by Means of Diffuse Reflectance Infrared Fourier Transform Spectroscopy

The diffuse reflectance infrared spectra of TiO₂ thin films deposited on different base materials and formed under different experimental conditions(temperature, ratio of tetrabutyl titanate to water and adulteration of different metallic elements) were determined and the structure of the films were discussed.     

Spectroscopic Properties and Electronic Structure of Bis(L—Histidine)Copper(II) Dinitrate Dihydrate

Electronic absorption spectrum, photoacoustic absorption spectrum and ESR spectrum of bis(L-histidine)copper(II) dinitrate dihydrate crystal were recorded. The experimental results are discussed quantitatively with ligand field theory (LFT) and the radial wave function of non-free copper(II). Our calculations coincides well with the experimental results, and in particular, provides significant correlations between the spectra and coordination structures. The ESR spectrum gives some information about the restudy of classification for the ESR spectra of bis(amino acidato)copper(II) complexs. Additionally, the differences between crystal and frozen solution spectra due to the variance of PH are also reported for the title compound.     

Spectroscopic Properties and Electronic Structure of (L-Glutamato)(2, 2′-Bipyridine) copper(II)

Cu(L-glu)(bpy)(L-glu = L-glutamato; bpy = 2, 2′-bipyridine) was prepared. Its electronic absorption spectrum and photoacoustic spectrum were recorded at room temperature. They were compared with each other and compared quantitatively with ligand field theory(LFT) and the radical wave function of non-free ions^[1–3]. Therefore, the electronic structure was also investigated with its spectrum behaviors and PLFT^[1–3].