ABSTRACT
OBJECTIVE To establish a quantitative analysis model for the contents of tussilagone， moisture， ethanol-soluble extract and total ash in Farfarae Flos based on near-infrared spectroscopy （NIRS）， providing a new idea for the rapid quality evaluation of Farfarae Flos and its preparations. METHODS Referring to the 2020 edition of the Chinese Pharmacopoeia， the contents of the main quality control indexes tussilagone， moisture， ethanol-soluble extract and total ash in 130 batches of Farfarae Flos from 19 producing areas were determined by HPLC， drying method， hot dip method and ash assay， respectively. The NIRS data information of the medicinal herbs of Farfarae Flos was collected， and then NIRS combined with the partial least squares method was used to establish the individual quantitative analysis models of the above quality control indexes in the samples， and the predictive model of the NIRS content was obtained after sample validation with validation set. RESULTS The range for the contents of tussilagone， moisture， ethanol-soluble extract and total ash in 130 batches of Farfarae Flos were 0.051 4%-0.103 5%， 7.75%-10.93%， 20.17%-31.12%， and 7.68%-12.10%， respectively. The internal cross-validation coefficients of determination （R2） of the established models for the quantitative analysis of tussilagone， moisture， ethanol-soluble extract and total ash in Farfarae Flos were 0.985 8， 0.968 4， 0.973 4， 0.988 0， respectively； the root mean square errors of calibration （RMSEC） were 0.001 54， 0.187， 0.478， 0.127， respectively； the root mean square errors of prediction （RMSEP） were 0.001 81， 0.212， 0.543， 0.149， respectively； RMSEP/RMSEC were 1.175 3， 1.133 7， 1.136 0 and 1.173 2， respectively， which were all within a reasonable range （1＜RMSEP/RMSEC≤1.2）. The mean absolute errors between the true and model-predicted values of the above four quality control indexes in the validation set of samples were －0.000 36， 0.061 43， 0.144 00， and 0.010 43， respectively，and the mean predicted recoveries were 99.65%， 100.72%，100.66%， and 100.15%， respectively. CONCLUSIONS The established NIRS quantitative analysis model has high stability and reliable results， which can be used for the rapid batch prediction of the content of relevant quality control indexes in Farfarae Flos.
ABSTRACT
OBJECTIVE@#To review the biomechanical research progress of internal fixation of tibial plateau fracture in recent years and provide a reference for the selection of internal fixation in clinic.@*METHODS@#The literature related to the biomechanical research of internal fixation of tibial plateau fracture at home and abroad was extensively reviewed, and the biomechanical characteristics of the internal fixation mode and position as well as the biomechanical characteristics of different internal fixators, such as screws, plates, and intramedullary nails were summarized and analyzed.@*RESULTS@#Tibial plateau fracture is one of the common types of knee fractures. The conventional surgical treatment for tibial plateau fracture is open or closed reduction and internal fixation, which requires anatomical reduction and strong fixation. Anatomical reduction can restore the normal shape of the knee joint; strong fixation provides good biomechanical stability, so that the patient can have early functional exercise, restore knee mobility as early as possible, and avoid knee stiffness. Different internal fixators have their own biomechanical strengths and characteristics. The screw fixation has the advantage of being minimally invasive, but the fixation strength is limited, and it is mostly applied to Schatzker typeⅠfracture. For Schatzker Ⅰ-Ⅳ fracture, unilateral plate fixation can be used; for Schatzker Ⅴand Ⅵ fracture, bilateral plates fixation can be used to provide stronger fixation strength and avoid the stress concentration. The intramedullary nails fixation has the advantages of less trauma and less influence on the blood flow of the fracture end, but the fixation strength of the medial and lateral plateau is limited; so it is more suitable for tibial plateau fracture that involves only the metaphysis. Choosing the most appropriate internal fixation according to the patient's condition is still a major difficulty in the surgical treatment of tibial plateau fractures.@*CONCLUSION@#Each internal fixator has good fixation effect on tibial plateau fracture within the applicable range, and it is an important research direction to improve and innovate the existing internal fixator from various aspects, such as manufacturing process, material, and morphology.