A Survey of Wild Birds Trading in the Beijing Bird Markets

Birds are an indispensable part of nature andthey play an important role in maintaining an ecologicalbalance. The existence of bird markets undoubtedlyposes a threat to the population of wild birds. Thegeographical location of Beijing is paramount to themigratory birds. The species of birds are rich in varietyand its quantity is large in scale. In addition, the birdmarket in old town Beijing has a long history - since theQing Dynasty, it has been the main bird market in thecity. Therefore, a survey of the major bird markets inthe city is highly representative. This study investigatedthe types, quantities, and prices of wild birds tradedin several major bird markets in Beijing from July16 to July 18, 2019. Data analysis and collation werealso conducted in this study. The results of the surveypresented 26 kinds of wild birds, with a total tradingvolume of an estimated 253. They are mainly birdsof the order of the passerine, 18 of which are underBeijing’s second-class protection, and one of them isunder first-class protection.

Oriented cellulose hydrogel:Directed tissue regeneration for reducing corneal leukoplakia and managing fungal corneal ulcers

Fungal corneal ulcer is one of the leading causes of corneal blindness in developing countries.Corneal scars such as leukoplakia are formed due to inflammation,oxidative stress and non-directed repair,which seriously affect the patients'subsequent visual and life quality.In this study,drawing inspiration from the oriented structure of collagen fibers within the corneal stroma,we first proposed the directional arrangement of CuTA-CMHT hydrogel system at micro and macro scales based on the 3D printing extrusion method combined with secondary patterning.It played an antifungal role and induced oriented repair in therapy of fungal corneal ulcer.The results showed that it effectively inhibited Candida albicans,Aspergillus Niger,Fusarium sapropelum,which mainly affects TNF,NF-kappa B,and HIF-1 signaling pathways,achieving effective antifungal functions.More importantly,the fibroblasts interacted with extracellular matrix(ECM)of corneal stroma through formation of focal adhesions,promoted the proliferation and directional migration of cells in vitro,induced the directional alignment of collagen fibers and corneal stromal orthogonally oriented repair in vivo.This process is mainly associated with MYLK,MYL9,and ITGA3 molecules.Furthermore,the downregulation the growth factors TGF-βand PDGF-βinhibits myofibroblast development and reduces scar-type ECM production,thereby reducing corneal leukoplakia.It also activates the PI3K-AKT signaling pathway,promoting corneal healing.In conclusion,the oriented CuTA-CMHT hydrogel system mimics the orthogonal arrangement of collagen fibers,inhibits inflammation,eliminates reactive oxygen species,and reduces corneal leukoplakia,which is of great significance in the treatment of fungal corneal ulcer and is expected to write a new chapter in corneal tissue engineering.