In Situ Synthesis of Cuprous Oxide/Cellulose Nanofibers Gel and Antibacterial Properties

Cellulose nanofibers were synthesized by acetobacter xylinum(xylinum 1.1812).The cellulose nanofibers with 30-90 nm width constructed three-dimension network gel,which could be used as a wound dressing since it can provide moist environment to a wound.However,cellulose nanofibers have no antimicrobial activity to prevent wound infection.To achieve antimicrobial activity,the cellulose nanofibers can load cuprous oxide(Cu2O)particles on the surface.The cuprous oxide is a kind of safe antibacterial material.The copper ions can be reduced into cuprous oxides by reducing agents such as glucose,N2H4 and sodium hypophosphite.The cellulose nanofibers network gel was soaked in CuSO4 solution and filled with copper ions.The cuprous oxide nanoparticles were in situ synthesized by glucose and embedded in cellulose nanofibers network.The morphologies and structure of the composite gel were analyzed by FESEM,FTIR,WAXRD and inductively coupled plasma(ICP).The sizes of Cu2O embedded in cellulose nanofibers network are 200-500 nm wide.The peak at 605 cm−1 attributed to Cu(I)-O vibration of Cu2O shits to 611 cm−1 in the Cu2O/cellulose composite.The Cu2O/cellulose nanofibers composite reveals the obvious characteristic XRD pattern of Cu2O and the results of ICP show that the content of Cu2O in the composite is 13.1%.The antibacterial tests prove that the Cu2O/cellulose nanofibers composite has the high antibacterial activities which is higher against S.aureus than against E.coli.

加强与周边发展中国家税务合作的思考——基于“亲诚惠容”理念与“一带一路”倡议

在习近平总书记提出的"亲诚惠容"周边外交理念与"一带一路"倡议指引下,中国与周边发展中国家的经济合作成果丰硕,国际税收合作日益加深。为了进一步帮助周边发展中国家提高税收征管能力,建议大力支持具备地缘优势的沿边省份在发展边境贸易合作基础上,搭建国际经贸合作区纳税服务综合平台,提升税收征管能力和税收情报交换能力,探索建立"四个体系",扎实开展与周边发展中国家的税务合作。