羟基磷灰石/胶原-聚乳酸三维多孔框架材料的制备成形及分析

目的：合成新型的复合生物材料框架作为骨组织工程研究的细胞外基质材料。方法：本研究采用材料学自组装技术的原理，以Ⅰ型胶原蛋白为分子模板，引导钙磷盐在液相中的矿化，制备具有天然骨基质层状结构的羟基磷灰石／胶原复合材料，并以热致分相法制备了羟基磷灰石／胶原-聚乳酸复合三维多孔框架。结果：羟基磷灰石／胶原复合材料具有与天然骨基质相似的成分与结构，加入聚乳酸制备成三维多孔框架，孔隙直径界于50um-300um。结论：羟基磷灰石／胶原-聚乳酸复合三维多孔框架可能作为骨组织工程良好的细胞外基质材料。     

Adhesion contact dynamics of HepG2 cells on galactose-immobilized substrates

The specific recognition between asialoglycoprotein receptor and galactose ligand at cell-substrate interfaces has been shown to mediate hepatocyte adhesion and maintain liver specific functions of hepatocytes. Conventionally, the success of hepatocyte attachment on engineered tissue scaffold is inferred from the degree of two-dimensional cell spreading that is measured by transmitted light microscopy. However, the actual contact mechanics and adhesion strength of hepatocytes during two-dimensional cell spreading has not been elucidated due to lack of biophysical probe. In this study, a novel biophysical technique known as confocal reflectance interference contrast microscopy (C-RICM) in conjunction with phase contrast microscopy is utilized to probe the adhesion dynamics, contact mechanics and two-dimensional spreading kinetics of HepG2 cells on galactose immobilized and collagen gel coated substrates. C-RICM demonstrates that HepG2 cells form strong adhesion contacts with both galactose-immobilized surfaces and collagen gel coated substrates. Moreover, HepG2 cells maintain their compact shapes in the presence of asialoglycoprotein receptor-mediated recognition while they become exceedingly spread under integrin-mediated adhesion on collagen gel coated substrate. The initial rate of adhesion contact formation and the steady-state adhesion energy of HepG2 cell population are highest on substrate conjugated with galactose ligand via a longer spacer. The adhesion dynamics and final adhesion energy of HepG2 cells depends both on the type of ligand-receptor interaction and the length of spacer between the ligand and substrate. Most importantly, new biophysical insights into the initial hepatocyte attachment that are critical for hepatocyte culture are provided through the decomposition of two-dimensional spreading and adhesion contact formation on bio-functional substrates.     

PKA对跨膜型和分泌TNF—α胞毒效应的影响

目的：研究ＰＫＡ对跨膜型ＴＮＦα（ｍＴＮＦ－α）杀瘤效应的影响。方法：用ＴＮＦ生物活性检测方法在体外观察ＰＫＡ激活剂和抑制剂对一型ＴＮＦ－α杀伤不同肿瘤细胞的影响。结果：ＰＫＡ激活剂Ｆｏｒｓｋｏｌｉｎ（１０μｍｏｌ／Ｌ）和抑制剂Ｈ８（１５μｍｏｌ／Ｌ）可分别增强和抑制ｓＴＮＦ－α对其第三靶细胞的胞毒活性,对其余４株耐受细胞却无逆转使用,而且对ｍＴＮＦ－α的胞毒效应无任何影响。此外,ＰＫＡ活性增强,     

青春期糖尿病雄鼠血清和性腺血管紧张素转换酶活性变化

４０日龄雄性Ｗｉｓｔａｒ大鼠２１只，分为对照（Ｃ）组，腹腔内注射赋形剂和糖尿病（Ｄ）组，腹腔内注射链脲菌素（ｓｔｒｅｐｔｏｚｏｔｏｃｉｎ，ＳＴＺ），５５ｍｇ／ｋｇ体重，观察６０天。结果表明，Ｄ组大鼠的睾丸、附睾、附睾尾重量显著低于Ｃ组（Ｐ＜０．０１）；Ｄ组附睾尾精子计数显著少于Ｃ组（Ｐ＜０．００１）。ＡＣＥ活性测定结果表明，Ｄ组睾丸和附睾尾组织ＡＣＥ活性显著低于Ｃ组（Ｐ＜０．０５），而血清ＡＣＥ显著高于Ｃ组（Ｐ＜０．０１），相关检验显示，附睾重量，附睾尾精子计数与附睾尾ＡＣＥ水平呈显著正相关（Ｐ＜０．０１），与血清ＡＣＥ呈显著负相关（Ｐ＜０．０５，Ｐ＜０．０１）。     

Analysis of fMRI data by blind separation of data in a tiny spatial domain into independent temporal component

Independent Component Analysis (ICA) is a promising tool for the analysis of functional magnetic resonance imaging (fMRI) time series. In these studies, mostly assumed is a spatially independent component map of fMRI data (spatial ICA). In this paper, we assume that the temporal courses of the signal and noises are independent within a Tiny spatial domain (temporal ICA). Then with fast-ICA algorithm, spatially neighboring fMRI data were blindly separated into several temporal courses and were preassumed to be formed by a signal time course and several noise time courses where the signal has the largest correlation coefficient with the reference signal. The final functional imaging was completed for the signals obtained from each voxel. Simulations showed that compared with the spatial ICA method, the new temporal ICA method is more effective than the spatial ICA in detecting weak signal in a fMRI dataset. As background noise, the simulations include simulated Gaussian noise and fMRI data without stimulation. Finally, vivo fMRI tests showed that the excited areas evoked by a visual stimuli are mainly in the region of the primary visual cortex and that evoked by auditory stimuli are mainly in the region of the primary temporal cortex.     

Synthesis and drug release behavior of poly (trimethylene carbonate)-poly (ethylene glycol)-poly (trimethylene carbonate) nanoparticles

ABA-type triblock copolymers poly (trimethylene carbonate)-poly (ethylene glycol)-poly (trimethylene carbonate) were synthesized by ring-opening polymerization of trimethylene carbonate initiated by dihydroxyl poly (ethylene glycol). The critical micelle concentration of amphiphilic triblock copolymers in aqueous solution was determined by fluorescence spectroscopy using 9-chloromethyl anthracene as fluorescence probe. Core-shell-type nanoparticles were prepared by the dialysis technique. Transmission electron microscopy images showed that these nanoparticles were regularly spherical in shape. Micelle size determined by dynamic light scattering is 50-160 nm. Anticancer drug methotrexate (MTX) as model drug was loaded in the polymeric nanoparticles. X-ray powder diffraction spectra showed that model drugs were molecularly dispersed in the core. In vitro release behavior of MTX was investigated.     

山紫菀与紫菀镇咳祛痰作用的实验研究

本实验对山紫菀(蹄叶橐吾Ligularia fischeri Turcz.)作了镇咳、祛痰作用的研究,并与紫菀(Aster tataricus L.)在同等条件下进行了比较,它们的浓缩水煎剂均有明显的祛痰作用,而无明显的镇咳作用,二者之间无显著性差异。它们的挥发油乳剂及水煎剂也均未表现出明显的镇咳作用。紫菀挥发油毒性大于山紫菀。