Rabbit Anti-CAT monoclonal antibody, clone KN22-23

The soft and hard acid-base theory (HSAB) is a new acid-base theory created by Sir. Pearson based on the theory of Lewis acid-base electron. It can be used to explain various chemical reactions, especially in coordination chemistry. In this study, the synthesized Cat.1 - Cat.6 [N,P]Ti catalysts containing ligands with electron withdrawing groups were prepared for ethylene polymerization without the addition of cocatalyst. The other optimal conditions for ethylene polymerization were determined through optimizing the polymerization behavior. Cat.5 with ligand L5 containing tetrafluorobenzene ring showed a catalytic activity of to 2.83 x 10(5) g(P).(mol(M))(-1).h(-1) for this polymerization. The obtained polyethylene featured high weight average molecular weight of 8.6 x 10(5) g/mol. The molecular weight distribution of polyethylene obtained by these six catalysts were in 2.2-2.5, and the melting point was about 135 degrees C The reaction mechanism of ethylene polymerization was explored by HSAB. The results showed that when the substituent on the catalyst aniline was an electron withdrawing group, both the polymerization activity and the molecular weight of the obtained polymer were higher. Density Functional Theory (DFT) results indicated that ethylene was more inclined to react with one of the M-C bonds of the catalyst. The energy barrier for the ethylene insertion reaction by Cat.5 was the lowest, compared to other catalysts except Cat.1, which made ethylene insertion reaction easier. These ligands containing electron withdrawing groups on aniline ring made the catalytic active species more stable. Much higher molecular weight of polyethylene was produced by utilizing these catalysts with the ligands containing electron withdrawing groups on aniline ring. These experimental results were consistent with those of HSAB and DFT.

This study evaluated the effects of dietary Clostridium butyricum on intestinal enzyme activity, intestinal histology, immune-related gene expression, short-chain fatty acids and intestinal microbiota in common carp (Cyprinus carpio L.). Three hundred and sixty fish (89.89 +/- 0.77 g) were divided into three groups and fed a diet supplemented with C. butyricum at 0, 0.125% (0.25 x 10(7) CFU/g), or 0.5% (1 x 10(7) CFU/g) (denoted as NC, LCB and HCB, respectively) for 8 weeks. Compared with the NC group, growth performances were not affected by adding C. butyricum. The enzyme activity of catalase (CAT) and lysozyme (LZM) in the intestine of the HCB group were significantly enhanced, and the butyric acid and propionic acid content in both C. butyricum-treated groups increased. In the HCB group, mucin secretion and the height of the epithelium microvilli were obviously increased, and the mucosal folds were deeper and smoother. The intestinal gene expression of IL-10, TLR-2, MyD-88, ZO-1 and Occludin were significantly higher in the HCB group than that in the control group but not in the LCB group. Dietary C. butyricum increased the diversity of the intestinal microbiota of common carp. At the phylum level, the abundance of Bacteroidetes improved concomitantly with a significant decrease in the abundance of Fusobacteria and Proteobacteria. At the genus level, the relative abundance of the beneficial bacteria Bacteroides and Cetobacterium increased remarkably in the HCB group, and pathogens such as Aeromonas, Vibrio, and Pseudomonas were inhibited. In conclusion, the results from this study indicate that supplementing the diet with C. butyricum at an appropriate dose can improve the intestinal immunity of common carp by regulating the intestinal microbiota and improving the defence function of the intestinal barrier.