ABSTRACT
Stable isotope dilution mass spectrometry(ID-MS)is a quantitative method for determining the content of unla?beled compounds with stable isotope labeled compounds as internal standard. Stable isotope dilution liquid chromatography-mass spec?trometry(ID-LC-MS)has the advantages of high sensitivity,no quantitative separation of the analytes,and effective elimination of the biological matrices. The method has been widely used in quantitative analysis of biomarkers,drugs and their metabolites. In this pa?per,the mechanism and characteristics of ID-LC-MS are briefly introduced,and its medical applications are summarized.
ABSTRACT
Based on the biomechanical response of human knee joint to a front impact in occupants accidents, a finite element (FE) model of human knee joint was developed by using computer simulation technique for impacting. The model consists of human anatomical structure, including femoral condyle, tibia condyle, fibular small head, patellar, cartilage, meniscus and primary ligament. By comparing the results of the FE model with experiments of the knee joint in axial load conditions, the validation of the model was verified. Furthermore, this study provides data for the mechanical of human knee joint injury, and is helpful for the design and optimization of the vehicle protective devices.
Subject(s)
Humans , Biomechanical Phenomena , Finite Element Analysis , Knee Injuries , Knee Joint , Physiology , Models, Anatomic , Models, BiologicalABSTRACT
Objective To explore the optimal techniques in separation of phenols from Melastoma dodecandrum with macroporous resins.Methods Static and dynamic adsorption-desorption methods were adopted,and the concentration of phenols was measured by UV spectrophotometer to evaluate the separa-ting efficiency.Results The HPD 100 macroporous resin was found with the best separating efficiency,by which the content of phenols could reach more than 50 percent in the extraction.The optimum technique condition was 0.2 g/mL concentration of crude drug,pH value was 2.7—4.5,adsorption in 3 BV/h,delution by 5 BV,60% alcohol in 3 BV/h.Conclusion This method is simple and feasible with good efficiency of separation,which could also meet the industrial requirements.