Objectives Osteoarthritis (OA) is a common degenerative joint disease with the pathological features of the reduced cartilage cellularity. Celastrol, a compound from Tripterygium wilfordii, exerted therapeutic effects on arthritis, but the potential mechanism remains unclear. Methods Tunicamycin was used to establish a model of OA in vitro, and ACLT surgery model in rats was applied to verify the mechanism. Chondrocytes were isolated from the knee articular cartilage of rabbit. MTT and flow cytometry assay were used to detect cell viability and apoptosis rate. Haematoxylin-eosin staining was used to assess for the histopathological changes. The activity and expression of apoptosis-related factors and ERs (endoplasmic reticulum stress)related factors were detected by ELISA, WB, PCR and IHC, respectively. Key findings Celastrol exhibited significant enhancement on cell viability and reduced the rate of apoptosis in Tm-exposed chondrocytes. Celastrol reduced enzyme activity and protein expression of caspase-3, caspase-6 and caspase-9, decreased Bip, Atf6, Chop and Xbp-1 expression both at protein and mRNA levels. Celastrol showed a more significant effect on cell apoptosis rate and mRNA expression in the combination with 4-PBA.Conclusions This study reveals that celastrol may prevent OA by inhibiting the ERs-mediated apoptosis. All these might supply beneficial hints for celastrol on OA treatment.

Conidia of Beauveria bassiana Bb-202, which have the potential for the control of the coleopteran pests, were produced on rice by solid-state fermentation (SSF) using tray bioreactor. As the solid substrate thickness increased, the production of conidia decreased. By cutting substrate into many small uniform pieces, metabolic heat and gas transfer in center of substrate could be improved. We concluded that the highest yield of 3.94×1012 conidia kg-1 rice was obtained as the substrate of 2cm thickness was cut into many small pieces (6cm×4cm×2cm). And the average yield of conidia increases by 45%. It indicated that cut solid substrate into many pieces would increasing the surface area of substrate. So the conidia yields were significantly increased.

In order to test the feasibility of co-composting for surplus sludge and garbage RD thermal decompositing nutrient soil, the mid-temperature composting experiments for the optimized conditions such as bacteria inoculating mode, initial moisture and pH were carried. The results showed that:(1) K-bacteria isolated from soil had a ability of decompositing insoluble mineral potassium to soluble forms at a rate of 9.20 μgK/200ml.h, and a decomposing ratio of 7.83% for potassium feldspar in liquid batch culturing. Moreover, after liquid enlargement culturing for 32h, the quantity of bacteria spores reached its climax, which ensured the high survival rate of K-bacteria. (2) The pre-compost inoculating mode (M1) was superior to post-compost (5th d M2) based on available nutrient or K-bacteria quantity increasing;(3) Through optimizing experiments, the best initial moisture of 50-60% and pH of 6.5 were determined with an ideal available nutrients and K-bacteria quantity in compost; (4) The inoculating of K-bacteria could increase the microbial quantity and activity, which may increase the heavy metal activity in compost, so the further researches on heavy metal passivation should be considered.