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Root canal (RC) therapy is the primary treatment of dental-pulp and periapical diseases. The mechanical method and chemical irrigation have limitations in RC therapy. Much attention has focused on exploring more controllable and efficacious antimicrobial methods. Although the introduction of photodynamic therapy (PDT) has provided the ideas for RC debridement, the problems of low photosensitive efficiency and nonsignificant germicidal potency of traditional photosensitizers (e.g., methylene blue) have not been solved. Since the concept of "aggregation-induced emission" (AIE) was proposed, optimization of photosensitizers has been boosted considerably. Herein, an AIE photosensitizer, DPA-SCP, with a strong ability to generate singlet oxygen, is proposed for use as an antibacterial application in infected RCs. The antimicrobial activity of DPA-SCP against Enterococcus faecalis suspensions was tested. To explore the antibacterial ability of this photosensitizer against bacterial-biofilm colonization on the inner walls of RCs, we established a model of bacterial biofilm infection. PDT mediated by DPA-SCP had a significant germicidal effect on E. faecalis suspensions and 21-day biofilms in human RCs. PDT mediated by DPA-SCP could achieve efficiency equivalent to that observed using 1% NaOCl, and lead to no significant change in the dentin surface, chemical corrosion, or cytotoxicity.

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In the north of China, the road is covered with the solid ice-snow which seriously affects the traffic safety of the city, it is a problem that how to clear the solid ice-snow quickly and efficiently. The concave disc clearing machine and the vertical milling clearing machine have been developed respectively based on the thought of agricultural machinery concave disc and vertical milling principle. The concave disc clearing machine is the clearing plate passively cutting ice-snow, which can complete crushing, cutting, scraping, tilt and push five operations. The vertical milling clearing machine is the cutting knife actively cutting ice-snow with function of milling, crushing, copying, obstacle etc, which has a very strong crushing capacity for ice film like high density ice-snow. The comprehensive clearing snow performance test of the concave disc and vertical milling clearing machine were performed under three kinds of road conditions. The test results show that the concave disc machine and the vertical milling machine have good operation, high working efficiency and the clearing rate are all higher than 90%, parameters setting and all indexes can meet the requirements of snow clearing operations. The concave disc machine is suitable for the plate compacted ice-snow which density is lower than 550 kg/m 3 and thickness range from10 mm to 80 mm. The vertical milling machine is suitable for the plate and ice film ice-snow which density range from 300 to 750kg/m 3 and thickness is lower than 50mm, especially suitable for ice film freezing ice -snow, which density is higher than 550kg/m 3 .