Physiologically Based Liver Modeling and Risk Assessment

Because of the inherent complexity of biological systems, there is often a choice between a number of apparently equally applicable physiologically based models to describe uptake and metabolism processes in toxicology or risk assessment. These models may fit the particular data sets of interest equally well, but may give quite different parameter estimates or predictions under different (extrapolated) conditions. Such competing models can be discriminated by a number of methods, including potential refutation by means of strategic experiments, and their ability to suitably incorporate all relevant physiological processes. For illustration, three currently used models for steady-state hepatic elimination--the venous equilibration model, the parallel tube model, and the distributed sinusoidal perfusion model--are reviewed and compared with particular reference to their application in the area of risk assessment. The ability of each of the models to describe and incorporate such physiological processes as protein binding, precursor-metabolite relations and hepatic zones of elimination, capillary recruitment, capillary heterogeneity, and intrahepatic shunting is discussed. Differences between the models in hepatic parameter estimation, extrapolation to different conditions, and interspecies scaling are discussed, and criteria for choosing one model over the others are presented. In this case, the distributed model provides the most general framework for describing physiological processes taking place in the liver, and has so far not been experimentally refuted, as have the other two models. These simpler models may, however, provide useful bounds on parameter estimates and on extrapolations and risk assessments.     

毛细管顶空气相色谱法测定饮用水中的氯仿和四氯化碳

建立了用毛细管顶空气相色谱法测定饮用水中氯仿和四氯化碳的方法。色谱条件为 非极性毛细管柱(30m×0.32mm×0.25μm),柱温40℃ 汽化室温度200℃,检测器为微池电子捕获检测器 检测器温度250℃ 载气为高纯N_2 流速3.2mL/min,尾吹气流速56.8mL/min,采用不分流进样 吹扫时间0.61min,吹扫流量20mL/min。实验表明 该方法准确度高,灵敏度比国标方法大大提高,适用于饮用水中氯仿和四氯化碳的分析测定。     

杯芳烃衍生物用作毛细管气相色谱固定液传质阻力系数的测定

研究杯芳烃衍生物二丁氧基杯［４］芳烃用作毛细管气相色谱固定液时醇同系物、苯同系物的传质阻力系数     

毛细管电泳法分离测定饮料中色素含量的研究

建立了毛细管电泳法直接分离测定饮料中日落黄、胭脂红、柠檬黄的方法,研究了缓冲溶液种类、浓度、pH值、电压等对分离的影响.在波长247 nm,分离电压15 kV,pH=10.0,10 mmol.L-1NaH2PO4-10 mmol.L-1Na2B4O7缓冲溶液中,日落黄、胭脂红、柠檬黄在8 min内得到了较好的分离,用于测定市售饮料中三组分含量得到满意结果.     

Two-dimensional generalisations of dynamic programming for image analysis

Dynamic programming (DP) is a fast, elegant method for solving many one-dimensional optimisation problems but, unfortunately, most problems in image analysis, such as restoration and warping, are two-dimensional. We consider three generalisations of DP. The first is iterated dynamic programming (IDP), where DP is used to recursively solve each of a sequence of one-dimensional problems in turn, to find a local optimum. A second algorithm is an empirical, stochastic optimiser, which is implemented by adding progressively less noise to IDP. The final approach replaces DP by a more computationally intensive Forward-Backward Gibbs Sampler, and uses a simulated annealing cooling schedule. Results are compared with existing pixel-by-pixel methods of iterated conditional modes (ICM) and simulated annealing in two applications: to restore a synthetic aperture radar (SAR) image, and to warp a pulsed-field electrophoresis gel into alignment with a reference image. We find that IDP and its stochastic variant outperform the remaining algorithms.     

RNA电泳结果和Northern blot效果的关系探讨

对RNA电泳结果和Northernblot效果的关系进行了探讨，结果表明利用RNA电泳结果可判断最终Northernblot的质量。     

非绝热毛细管中制冷剂流动特性的数学模型及数值计算

本文建立了非绝热毛细管中制冷剂流动特性的数学模型，利用隐式差分格式和Ｒｕｎｇｅ－Ｋｕｔｔａ方法对该模型进行了数值计算，并与实验结果进行了比较．     

毛细管电泳内标法测定奶制品中三聚氰胺含量

建立了毛细管电泳内标法检测牛奶、奶粉、奶片和奶茶中三聚氰胺含量的方法.研究了缓冲溶液种类、浓度、pH值、电压等对分离的影响,并对分离条件进行了优化.在波长236nm、分离电压15kV、pH 2.0、15mmol·L-1磷酸二氢钠缓冲溶液中,以邻苯二胺为内标物,三聚氰胺在7min内得到较好的分离,三聚氰胺在1.5~200mg·L-1范围内具有良好是线性关系,平均加标回收率为96.2%.     

毛细管电泳法直接分离检测水溶液中Cd2+、Cu2+、Ni2+、Zn2+的研究

建立了毛细管电泳法直接分离测定水样中Cd2 、Cu2 、Ni2 、Zn2 金属离子的方法,研究了缓冲溶液种类、浓度、pH值、有机添加剂等对分离的影响,对分离条件进行了优化.在波长223nm,分离电压25kV,pH=4.30,150 mmol/L HAc-NaAc乙醇(20%)缓冲溶液中,使Cd2 、Cu2 、Ni2 、Zn2 与邻二氮菲形成的配合物在4 min内得到了较好的分离,迁移时间和峰面积的相对标准偏差分别小于0.95%和3.5%,且浓度与峰面积之间具有良好的线性关系.     

L-白氨酸拆分手性药物的毛细管电泳实验

将教学与科研相结合,以科研成果充实和更新实验教学内容.借助一个快速、简单、实用的毛细管电泳实验,帮助学生了解毛细管电泳分析技术中的一些基本概念及其实际应用情况.