AIM To prepare oral colon-specific metronidazole microsphere delivery system. METHODS Metronidazole microspheres were prepared with Quasi-emulsion method, and the colon site-specific delivery prescription and preparat...AIM To prepare oral colon-specific metronidazole microsphere delivery system. METHODS Metronidazole microspheres were prepared with Quasi-emulsion method, and the colon site-specific delivery prescription and preparation optimized with fractional factorial design. RESULTS The drug loading of colon site-specific delivery metronidazole microspheres was (39 94±0 15)%, and release fraction 71 78% in an artificial colon solution. CONCLUSION Optimized by fractional factorial design metronidazole microspheres possess the characteristics of a colon site-specific delivery system that delivers its most part in an artificial solution.展开更多
Dielectric barrier discharges （DBD） have been used in the degradation of dioxins due to the large number of excimers and free radicals produced in discharge process. In this article, the density functional theory （...Dielectric barrier discharges （DBD） have been used in the degradation of dioxins due to the large number of excimers and free radicals produced in discharge process. In this article, the density functional theory （DFT） is used to study the degradation mechanism of octachlorinated dibenzo-p-dioxin （OCDD） with the atomic oxygen O（3P） in DBD reactor. The reactants, intermediates, transition states and products are optimized at the MPWB1K/6- 31 ＋ G（d,p） level. The vibrational frequencies have been calculated at the same level. The reaction pathways and mechanisms are analyzed in detail. The effect of removing the chlorine atom on environment also has been discussed.展开更多
The current concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDD/Fs） were determined in soils contaminated with Chinese technical product sodium pentachlorophenate （ Na- PCP）. The estimated ...The current concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDD/Fs） were determined in soils contaminated with Chinese technical product sodium pentachlorophenate （ Na- PCP）. The estimated half-life of octachlorodioxin （OCDD） was about 14 years in contaminated soils based on the local historical record and mass balance calculation during the past 43 years（ 1960-2003）. The isomer profiles remained the same regardless of paddy field soil or riverbank soil. The results indicated that the congenerspecific information was efficient in estimating the PCDD/Fs fate in contaminated soils.展开更多
文摘AIM To prepare oral colon-specific metronidazole microsphere delivery system. METHODS Metronidazole microspheres were prepared with Quasi-emulsion method, and the colon site-specific delivery prescription and preparation optimized with fractional factorial design. RESULTS The drug loading of colon site-specific delivery metronidazole microspheres was (39 94±0 15)%, and release fraction 71 78% in an artificial colon solution. CONCLUSION Optimized by fractional factorial design metronidazole microspheres possess the characteristics of a colon site-specific delivery system that delivers its most part in an artificial solution.
基金supported by the National Natural Science Foundation of China (No. 21277082, 21177076, 71201093)the Promotive Research Fund for Excellent Young and Middleaged Scientists of Shandong Province (Nos. BS2012HZ009, BS2012SF012)+2 种基金Graduate Independent Innovation Foundation of Shandong University (No. yzc12120)Program for New Century Excellent Talents in University (NCET-13-0349)Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Community Framework Program (No. 295132)
文摘Dielectric barrier discharges （DBD） have been used in the degradation of dioxins due to the large number of excimers and free radicals produced in discharge process. In this article, the density functional theory （DFT） is used to study the degradation mechanism of octachlorinated dibenzo-p-dioxin （OCDD） with the atomic oxygen O（3P） in DBD reactor. The reactants, intermediates, transition states and products are optimized at the MPWB1K/6- 31 ＋ G（d,p） level. The vibrational frequencies have been calculated at the same level. The reaction pathways and mechanisms are analyzed in detail. The effect of removing the chlorine atom on environment also has been discussed.
文摘The current concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDD/Fs） were determined in soils contaminated with Chinese technical product sodium pentachlorophenate （ Na- PCP）. The estimated half-life of octachlorodioxin （OCDD） was about 14 years in contaminated soils based on the local historical record and mass balance calculation during the past 43 years（ 1960-2003）. The isomer profiles remained the same regardless of paddy field soil or riverbank soil. The results indicated that the congenerspecific information was efficient in estimating the PCDD/Fs fate in contaminated soils.
