Abstract In this study, type II collagen was used to induce arthritis in mice to test the effect and mechanism of dandelion tea. The visual manifestations of arthritis, histopathological conditions of spleen, serum inflammatory factors and gene expression of synovium of foot and ankle joints in mice were detected by the methods of arthritis index (AI), spleen index, enzyme linked immunosorbent assay (ELISA), hematoxylin-eosin (H&E) staining and quantitative polymerase chain reaction (qPCR). The compound components of dandelion tea were determined by high performance liquid chromatography (HPLC). The experimental results show that dandelion tea can reduce the AI value, spleen index and paw swelling degree of arthritis mice, reduce the pathological damage of spleen, and increase the serum IL-10 and TGF-β levels, and can up-regulate Foxp3 expression and down regulate ROR-γt expression in the synovium of ankle joint. At the same time, the results of component analysis showed that the efficacy of dandelion tea came from the contents of gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, p-coumaric acid, rutin, myricetin, isoquercitrin, isochlorogenic acid and luteolin. It can be seen that dandelion tea is a health drink with good intervention effect on arthritis.

Solid acid-catalyzed dehydration of fructose to produce 5-hydroxymethylfurfural (5-HMF) has been a hotspot in biomass conversion research in recent years. In this study, a novel SAPO-34-based catalyst was prepared by consecutive steps of titanium doping, sulfuric acid impregnation, and sulfonic acid functionalization. Characterization of the catalyst with X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), BrunauerEmmett-Teller (BET), inductively coupled plasma optical emission spectrometer (ICP-OES), and acid-base titration revealed different pore structures and more acid content compared to SAPO-34. The catalyst was applied to the preparation of 5-HMF by dehydration of fructose, and the maximum yield (74.0%) of 5-HMF was obtained by reacting in dimethyl sulfoxide (DMSO) at 170 °C for 50 min. In addition, the applicability of the catalytic system to other substrates and the stability of the catalyst after five cycles were investigated, which are valuable for further probing on the concerned aspects.

Four kinds of neutral and alkaline protease genes from Aspergillus oryzae and Bacillus subtilis were isolated and shuffled. The shuffled genes were selected, inserted into pGAPZαA plasmid and transformed into Escherichia coli. The gene which could express high-activity protease was selected by screening the sizes of transparent zones around the colonies on casein plates. After an ideal protease gene was selected, it was sequenced and then transformed into Pichia pastoris X33. The result showed that the base in 1022th position of shuffled protease gene was changed from thymine to cytosine, inferring that cysteine was changed to arginine in the mutant protease. After 48 h incubation for the transformed P. pastoris with the mutant or native protease genes, the mutant protease activity was 36.4% higher than the native protease (P<0.05). The optimal pH and temperature of the mutant protease were 6.5-8.0 and 30-70°C, respectively, which indicated better stability than the native protease (P<0.05).