Separation of Panax notoginseng saponins on modified rosin ester-bonded silica stationary phase and its mechanism.

A column prepared using a unique three-membered phenanthrene skeleton of rosin has complementary selectivity to a C18 column for some separation tasks. In this study, propylene pimaric acid (16-hydroxyethyl acrylate-34-n-butyl) ester (BRB) and propylene pimaric acid (16-hydroxyethyl acrylate-34-dodecyl) ester (BRLA) were used as functional ligands to prepare two novel stationary phases, namely BRB@SiO2 and BRLA@SiO2, through a "thiol-ene" click chemistry reaction. The characterization results of Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption measurements, and contact angle tests showed that the BRB@SiO2 and BRLA@SiO2 stationary phases were successfully prepared. In addition, the performance of the columns was evaluated using the Tanaka test and hydrophobic subtraction model, which showed that the stationary phases exhibited typical reversed-phase chromatography performance and good hydrophobicity, hydrophobic selectivity, and steric selectivity. The changes in the retention of Panax notoginseng saponins on a column under different chromatographic conditions (acetonitrile content, flow rate, and column temperature) were investigated. The separation effect of BRB@SiO2 and BRLA@SiO2 columns on P. notoginseng saponins was better than that of the C18 column and the BRLA@SiO2 column could replace the C18 column for the detection of P. notoginseng saponins.

A novel polynomial membership functions based control method for T-S fuzzy systems.

To solve the state feedback stabilization problem for a class of T-S fuzzy systems, a new stability synthesis method is raised to further relax the conservatism existing in the analysis process. First, a series of nonlinear polynomials are used to approximate the system membership functions. And satisfied approximation results can be obtained. Then a polynomials transformation method is raised to change the polynomial membership functions into linear form. This method can facilitate the synthesis process and achieve better approximation precision. Therefore, by a membership function involving stability analysis approach, linear matrix inequality form stability conditions are given. Finally, by presenting and analyzing a numerical and a practical examples, the conservatism reduction effects of the proposed methods are verified.

Membership Function Derivatives Transformation Approach for Stability Analysis and Stabilization Control of T-S Fuzzy Systems.

In this text, a membership function derivatives (MFDs) extrema-based method is proposed to relax the conservatism both in stability analysis and synthesis problems of Takagi-Sugeno fuzzy systems. By the designed algorithm, the nonpositiveness of the MFDs extrema is conquered. For an open-loop system, based on certain information of the MFs and derivatives, a series of convex stability conditions is derived. Then, an extremum-based construction method is adopted to involve the MF information. For the shape of MFDs, a coordinate transformation algorithm is proposed to involve it in the stability conditions to achieve local stable effects. For a state-feedback control system, conditions guaranteeing the stability and robustness are listed. Finally, simulation examples and comparisons are carried out to clarify the conservatism reduction results of the raised method.

Effects of polaprezinc on gastric mucosal damage and neurotransmitters in a rat model of chemotherapy-induced vomiting.

Objective To investigate the effects of polaprezinc (PZ) on cyclophosphamide (CTX)- or cisplatin (DDP)-induced gastric mucosal injury and on a rat model of neurotransmitter-mediated vomiting. Methods Sprague-Dawley rats were divided at random into Control, CTX, DDP, PZ+CTX, and PZ+DDP groups. After 20 days, brain tissues and sera were analyzed for the levels of dopamine (DA), 5-hydroxytryptamine (5-HT), and nuclear factor kappa B (NF-κB). Hematoxylin and eosin-stained sections of stomach, intestine, and brain tissues were examined using light microscopy. Results The levels of DA, 5-HT, and NF-κB in brain and serum samples of rats treated with CTX or DDP were significantly increased compared with those of rats in the Control group. There was a significant decrease in these values in the PZ group. Moreover, PZ reduced damage to brain tissue caused by CTX or DDP. Conclusions PZ decreased the levels of DA, 5-HT, and NF-κB in blood and brain tissues caused by CTX or DDP and reduced the chemotherapy-induced damage to the small intestine, stomach, and brain. These findings can be translated to the clinic to enhance the efficacy and safety of chemotherapy.