An acid-sensitive delivery system based on acylhydrazone bond was developed for high loading and efficient delivery of doxorubicin.Doxorubicin(DOX)was covalently combined with dihydrazide adipate to form acid-sensitiv...An acid-sensitive delivery system based on acylhydrazone bond was developed for high loading and efficient delivery of doxorubicin.Doxorubicin(DOX)was covalently combined with dihydrazide adipate to form acid-sensitive hydrazone bond based on Schiff base reaction,then the intermediate was covalently combined with carboxymethyl chitosan through amide bond to form polymeric prodrugs,and nanoparticles were formed through self-assembling.Moreover,the structural and particle properties of CMCS-ADH-DOX were characterized by ultraviolet visible near infrared spectrophotometry(UV),nuclear magnetic resonance spectroscopy(^(1)H-NMR),fourier transform infrared spectroscopy(FT-IR),dynamic light scattering(DLS),and transmission electron microscopy(TEM).The mean diameter of the self-assembled nanoparticles is 165 nm,while the morphology is a relatively uniform spherical shape.Moreover,these DOXloaded nanoparticles showed pH-triggered drug release behavior.Compared with free DOX,CAD NPs showed lower toxic side effects in L929 cells and similar toxicity in 4T1 cells.The experimental results indicate that the CMCS-ADH-DOX nanoparticles may be used as an acid-sensitive targeted delivery system with good application prospect for cancer.展开更多
城市轨道交通基础设施碳排放的定量研究已经成为交通运输领域低碳建设的关注焦点。以Web of Science(WOS)核心数据库和中国知网数据库为基础,对城市轨道交通基础设施碳排放的定量研究进行系统性综述与分析,从研究方法和影响因素2个方面...城市轨道交通基础设施碳排放的定量研究已经成为交通运输领域低碳建设的关注焦点。以Web of Science(WOS)核心数据库和中国知网数据库为基础,对城市轨道交通基础设施碳排放的定量研究进行系统性综述与分析,从研究方法和影响因素2个方面对样本文献进行深入分析与归纳,共涉及4种类型基础设施的碳排放,具体包括地铁系统(包括隧道和车站)、轻轨系统、市域快速轨道交通系统和有轨电车系统。首先对关于碳排放计算的文献的研究方法、目标与范围界定、功能单位和清单数据进行比较,确定研究方法的适用范围,并对数据来源进行分类;其次,确定并分析影响城市轨道交通基础设施隐含碳排放的关键因素;最后,讨论现有研究的不足。研究结果可为城市轨道交通基础设施碳排放核算标准化提供参考。展开更多
基金Funded by the Industrial Technology Research Institute of Hubei Provincial Department of Science and Technology(No.2020DEB012)the Hubei Provincial Department of Science and Technology Support Enterprise Technology Innovation Development Project(No.2021BAB119)。
文摘An acid-sensitive delivery system based on acylhydrazone bond was developed for high loading and efficient delivery of doxorubicin.Doxorubicin(DOX)was covalently combined with dihydrazide adipate to form acid-sensitive hydrazone bond based on Schiff base reaction,then the intermediate was covalently combined with carboxymethyl chitosan through amide bond to form polymeric prodrugs,and nanoparticles were formed through self-assembling.Moreover,the structural and particle properties of CMCS-ADH-DOX were characterized by ultraviolet visible near infrared spectrophotometry(UV),nuclear magnetic resonance spectroscopy(^(1)H-NMR),fourier transform infrared spectroscopy(FT-IR),dynamic light scattering(DLS),and transmission electron microscopy(TEM).The mean diameter of the self-assembled nanoparticles is 165 nm,while the morphology is a relatively uniform spherical shape.Moreover,these DOXloaded nanoparticles showed pH-triggered drug release behavior.Compared with free DOX,CAD NPs showed lower toxic side effects in L929 cells and similar toxicity in 4T1 cells.The experimental results indicate that the CMCS-ADH-DOX nanoparticles may be used as an acid-sensitive targeted delivery system with good application prospect for cancer.
文摘城市轨道交通基础设施碳排放的定量研究已经成为交通运输领域低碳建设的关注焦点。以Web of Science(WOS)核心数据库和中国知网数据库为基础,对城市轨道交通基础设施碳排放的定量研究进行系统性综述与分析,从研究方法和影响因素2个方面对样本文献进行深入分析与归纳,共涉及4种类型基础设施的碳排放,具体包括地铁系统(包括隧道和车站)、轻轨系统、市域快速轨道交通系统和有轨电车系统。首先对关于碳排放计算的文献的研究方法、目标与范围界定、功能单位和清单数据进行比较,确定研究方法的适用范围,并对数据来源进行分类;其次,确定并分析影响城市轨道交通基础设施隐含碳排放的关键因素;最后,讨论现有研究的不足。研究结果可为城市轨道交通基础设施碳排放核算标准化提供参考。
