Dry powder inhalers(DPIs) had been widely used in lung diseases on account of direct pulmonary delivery, good drug stability and satisfactory patient compliance. However, an indistinct understanding of pulmonary deliv...Dry powder inhalers(DPIs) had been widely used in lung diseases on account of direct pulmonary delivery, good drug stability and satisfactory patient compliance. However, an indistinct understanding of pulmonary delivery processes(PDPs) hindered the development of DPIs. Most current evaluation methods explored the PDPs with over-simplified models, leading to uncompleted investigations of the whole or partial PDPs. In the present research, an innovative modular process analysis platform(MPAP) was applied to investigate the detailed mechanisms of each PDP of DPIs with different carrier particle sizes(CPS). The MPAP was composed of a laser particle size analyzer, an inhaler device,an artificial throat and a pre-separator, to investigate the fluidization and dispersion, transportation,detachment and deposition process of DPIs. The release profiles of drug, drug aggregation and carrier were monitored in real-time. The influence of CPS on PDPs and corresponding mechanisms were explored. The powder properties of the carriers were investigated by the optical profiler and Freeman Technology four powder rheometer. The next generation impactor was employed to explore the aerosolization performance of DPIs. The novel MPAP was successfully applied in exploring the comprehensive mechanism of PDPs, which had enormous potential to be used to investigate and develop DPIs.展开更多
A method is described here for the quickly(<30 s) accurate determination of Cr(VI)(Cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GS...A method is described here for the quickly(<30 s) accurate determination of Cr(VI)(Cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GSH). The fluorescence of the AuNDs responses linearly to Cr(VI) concentrations, ranging widely from 1 nM to 10 m M with detection limit as low as 0.35 nM. At the same time, the AuNDs is demonstrated highly selective for Cr(VI) detection over other acid group ions and metal ions without any masking reagent. These make probability for practical use. The quenching mechanism is investigated deeply via fluorescent lifetime, XPS and TEM analysis. Different from most reported quenching explanation of aggregation derived from charge attraction, these results verify the redox reaction between Cr_2O_7^(2-)and sulfhydryl(–S) of GSH. The Au(I)–S bonds of AuNDs broke, accompanies with the oxidation of –S to form S–S bonds. As a result, AuNDs cross linked to each other. In the end, the fluorescence quenched. Attractively, the present study provides a new strategy for pollutant detection, such as from harmful Cr(VI) of Cr_2O_7^(2-)to nontoxic Cr(III).展开更多
基金funded by the Fundamental Research Funds for the Central Universities(Nos.21620434 and 2162014,China)the National Natural Science Foundation of China(Nos.81673375 and 81703431)+1 种基金the Science and Technology Foundation Guangzhou(No.201509030006,China)the National Students Innovation Training Program of China(No.201901390,China)。
文摘Dry powder inhalers(DPIs) had been widely used in lung diseases on account of direct pulmonary delivery, good drug stability and satisfactory patient compliance. However, an indistinct understanding of pulmonary delivery processes(PDPs) hindered the development of DPIs. Most current evaluation methods explored the PDPs with over-simplified models, leading to uncompleted investigations of the whole or partial PDPs. In the present research, an innovative modular process analysis platform(MPAP) was applied to investigate the detailed mechanisms of each PDP of DPIs with different carrier particle sizes(CPS). The MPAP was composed of a laser particle size analyzer, an inhaler device,an artificial throat and a pre-separator, to investigate the fluidization and dispersion, transportation,detachment and deposition process of DPIs. The release profiles of drug, drug aggregation and carrier were monitored in real-time. The influence of CPS on PDPs and corresponding mechanisms were explored. The powder properties of the carriers were investigated by the optical profiler and Freeman Technology four powder rheometer. The next generation impactor was employed to explore the aerosolization performance of DPIs. The novel MPAP was successfully applied in exploring the comprehensive mechanism of PDPs, which had enormous potential to be used to investigate and develop DPIs.
基金supported by the National Natural Science Foundation of China(51373061,21304090)Emphases Science and Technology Research Program of Jilin Province Science and Technology Development Plan(20180201060SF)Science Foundation of China University of Petroleum,Beijing(2462017YJRC027)
文摘A method is described here for the quickly(<30 s) accurate determination of Cr(VI)(Cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GSH). The fluorescence of the AuNDs responses linearly to Cr(VI) concentrations, ranging widely from 1 nM to 10 m M with detection limit as low as 0.35 nM. At the same time, the AuNDs is demonstrated highly selective for Cr(VI) detection over other acid group ions and metal ions without any masking reagent. These make probability for practical use. The quenching mechanism is investigated deeply via fluorescent lifetime, XPS and TEM analysis. Different from most reported quenching explanation of aggregation derived from charge attraction, these results verify the redox reaction between Cr_2O_7^(2-)and sulfhydryl(–S) of GSH. The Au(I)–S bonds of AuNDs broke, accompanies with the oxidation of –S to form S–S bonds. As a result, AuNDs cross linked to each other. In the end, the fluorescence quenched. Attractively, the present study provides a new strategy for pollutant detection, such as from harmful Cr(VI) of Cr_2O_7^(2-)to nontoxic Cr(III).
