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Objective: Pretreatment of biological samples is the most critical step in pharmacokinetic studies, especially pre-treatment of plasma samples. The pretreatment of biological samples in pharmacokinetic study of Traditional Chinese Medicines (TCM) is difficult due to the complexity of the ingredients. An organic solvent system ethyl acetate: acetone (10: 1) solution used for liquid-liquid extraction has been developed in this study and compared with the commonly used protein precipitation method. Methods: Rats, Beagle dogs and humans plasma samples were adopted in this study in order to demonstrate the universality of the pretreatment method. Feasibility of this pretreatment method was also verified through its application to the pharmacokinetics of rhubarb in rats. Results: According to the results of extraction recovery matrix effect, it was indicated that the liquid-liquid extraction methods with new organic solvent might be suitable for variety of structures of compounds and various types of plasma samples. The pharmacokinetic study result showed that the developed pretreatment method could successfully be used for simultaneous determination of three active compounds modin, emodin-8-O-β-D-glucopyranoside (EDG) and rhein in rat plasma with high sensitivity, accuracy, and recovery by liquid chromatography tandem mass spectrometry (LC-MS/MS). Conclusion: The pretreatment method of liquid-liquid extraction methods with new organic solvent could be successfully applied for multi-component pharmacokinetics of TCM. Keywords: Pretreatment method, Liquid-liquid extraction, Protein precipitation, LC-MS/MS, Rhubarb

To further improve ring laser gyroscope (RLG) bias stability, a multiple-point temperature gradient algorithm is proposed for RLG bias compensation in this paper. Based on the multiple-point temperature measurement system, a complete thermo-image of the RLG block is developed. Combined with the multiple-point temperature gradients between different points of the RLG block, the particle swarm optimization algorithm is used to tune the support vector machine (SVM) parameters, and an optimized design for selecting the thermometer locations is also discussed. The experimental results validate the superiority of the introduced method and enhance the precision and generalizability in the RLG bias compensation model.

Angelica sinensis root (ASR) extract was obtained to investigate its effects on colorectal carcinogenesis in different stages of an Azoxymethane/Dextran sodium sulphate (AOM/DSS) model. In this study, we showed that ASR extract administration in the initial stage of the AOM/DSS model had cancer preventive effects with decreasing tumor incidence and a high-grade of intraepithelial neoplasia incidence. With respect to DNA damage, the amounts of 8-oxoguanine and γ-H2AX were suppressed in colon tissue. The balance of apoptosis and proliferation was approaching the normal state. In contrast, ASR extract administration in the promotion stage of the AOM/DSS model accelerated the progression of carcinogenesis. The maximum tumor size reached 49.85 ± 25.04 mm3. High-grade pathological changes were significantly increased. Decreased DNA damage and P53 level reflected the disrupted reactive oxygen species (ROS) concentration in colorectal tissue, which led to an imbalance of proliferative and apoptotic relationships. These findings suggested that the cancer-preventive effect of ASR extract may be stage-dependent in the process of carcinogenesis.