Background: This experiment was conducted to study the effect of different feed enzymes(phytase,xylanase,β-glucanase) on release rate of trace elements(Fe,Cu,Mn and Zn) in 6 commonly used feedstuffs(corn,wheat,barley...Background: This experiment was conducted to study the effect of different feed enzymes(phytase,xylanase,β-glucanase) on release rate of trace elements(Fe,Cu,Mn and Zn) in 6 commonly used feedstuffs(corn,wheat,barley,soybean meal,wheat bran,wheat middlings) by using an in vitro model,simulating the digestive processes in stomach for 2 h and then in small intestine for 6 h at 39 °C.Results: Phytase raised(P < 0.05) the release rate of Cu and Zn in corn,Cu,Zn and Mn in wheat,Cu in barley,Cu,Zn and Mn in soybean meal,Zn,Fe in wheat bran and Zn,Fe,Mn in wheat middlings.The release rate of various trace elements in feedstuffs was increased after xylanase addition.Compared with the control group,the release rate of soluble Cu in corn,wheat,barley and soybean meal,soluble Zn in corn,wheat and wheat middlings and soluble of Mn in corn,wheat,barley and wheat bran increased(P < 0.05) after xylanase treatment.After the treatment of β-glucanase,the release rate of soluble Cu in corn,wheat and wheat bran,soluble Fe in barley,soybean meal and wheat bran and soluble Mn in corn and wheat bran all increased(P < 0.05) compared with the control group.In each feedstuff,after corresponding enzyme treatment,the contents of phytic acid,xylan and β-glucan were significantly lower than those of the control group(P < 0.05).Conclusions: Results showed that bound trace elements in feedstuffs can be released by feed enzymes.It may be necessary to take the trace elements in feedstuffs into account in the actual feed preparation including feed enzymes.展开更多
The objective of this study was to develop once-daily metformin hydrochloride sustained-release tablets (MHSRT) and evaluate their in vitro release behavior. MHSRT were prepared by the film coating method. The in vitr...The objective of this study was to develop once-daily metformin hydrochloride sustained-release tablets (MHSRT) and evaluate their in vitro release behavior. MHSRT were prepared by the film coating method. The in vitro drug release rate of MHSRT and the commercial tablets Fortamet? made in the United States of America in water was fitted with zero order kinetic equation, and Ritger-Peppas kinetic equation in 0.1 M HCl and pH 6.8-phosphate buffer, respectively. The similarity factor f2 values of MHSRT in three different dissolution medium were 82, 80 and 74, respectively in comparison with imported Fortamet?, which were all greater than 50. The results of storage-stability showed that MHSRT were stable for at least 6 months under stress condition (40℃ ± 2℃, RH 75% ± 5%). Therefore, in this study, MHSRT were successfully prepared using optimized formulation technologies that meet mass produce. The in vitro release behavior of MHSRT was almost similar to that of imported Fortamet?.展开更多
According to the deficiency of the strain accumulating and releasing curves and the previous models, the strain-accumulating rate of the strain accumulating and releasing model has been deduced based on the G-R relati...According to the deficiency of the strain accumulating and releasing curves and the previous models, the strain-accumulating rate of the strain accumulating and releasing model has been deduced based on the G-R relation and the empirical formula between energy release and earthquake magnitude, where the strain-accumulating rate is relative independent of the strain-releasing rate. Five typical areas in Chinese mainland are selected on the basis of the hypothesis on active tectonic block, and small earthquakes from 1970 are imported to calculate the annual strain-accumulating rates considering the completeness of historical seismic data. Having introduced the strain-accumulating rates into the amended model, present strain phases are got. According to the present stages in their own cycles, the future earthquake tendency of each sub-region is discussed.展开更多
目的:制备水飞蓟素肠溶聚乳酸-羟基乙酸共聚物(PLGA)纳米粒,并研究其体外释药行为。方法:以羟丙基甲基纤维素邻苯二甲酸酯(HPMCP)为肠溶材料,采用纳米沉淀法制备水飞蓟素肠溶PLGA纳米粒和水飞蓟素PLGA纳米粒,观察其形态,检测其粒径、Zet...目的:制备水飞蓟素肠溶聚乳酸-羟基乙酸共聚物(PLGA)纳米粒,并研究其体外释药行为。方法:以羟丙基甲基纤维素邻苯二甲酸酯(HPMCP)为肠溶材料,采用纳米沉淀法制备水飞蓟素肠溶PLGA纳米粒和水飞蓟素PLGA纳米粒,观察其形态,检测其粒径、Zeta电位、包封率、载药量、稳定性、体外释放度(Q)。以粒径、包封率、载药量为指标筛选水飞蓟素肠溶PLGA纳米粒中PLGA-HPMCP质量比。结果:PLGA-HPMCP的最佳质量比为1∶0.25。所制水飞蓟素肠溶PLGA纳米粒和水飞蓟素PLGA纳米粒的粒径分别为224、193 nm,Zeta电位分别为-37.8、-40.7 m V;包封率分别为(74.7±2.2)%、(71.7±2.5)%,载药量分别为(5.39±0.24)%、(5.21±0.22)%;4℃下储存3个月后的渗漏率分别为0.2%、0.5%;人工胃液中Q_(48h)分别为38.6%、70.5%,人工肠液中Q48 h分别为80.2%、73.5%。结论:成功制得水飞蓟素肠溶PLGA纳米粒,其稳定性较好,能有效抑制水飞蓟素在人工胃液中的释放。展开更多
基金supported by the National Key R&D Program of China(No.2016YFD0501201)National Natural Sciences Foundation of China(No.31472102,No.31772607)Zhejiang Provincial Key Science Project(No.2015C03006)
文摘Background: This experiment was conducted to study the effect of different feed enzymes(phytase,xylanase,β-glucanase) on release rate of trace elements(Fe,Cu,Mn and Zn) in 6 commonly used feedstuffs(corn,wheat,barley,soybean meal,wheat bran,wheat middlings) by using an in vitro model,simulating the digestive processes in stomach for 2 h and then in small intestine for 6 h at 39 °C.Results: Phytase raised(P < 0.05) the release rate of Cu and Zn in corn,Cu,Zn and Mn in wheat,Cu in barley,Cu,Zn and Mn in soybean meal,Zn,Fe in wheat bran and Zn,Fe,Mn in wheat middlings.The release rate of various trace elements in feedstuffs was increased after xylanase addition.Compared with the control group,the release rate of soluble Cu in corn,wheat,barley and soybean meal,soluble Zn in corn,wheat and wheat middlings and soluble of Mn in corn,wheat,barley and wheat bran increased(P < 0.05) after xylanase treatment.After the treatment of β-glucanase,the release rate of soluble Cu in corn,wheat and wheat bran,soluble Fe in barley,soybean meal and wheat bran and soluble Mn in corn and wheat bran all increased(P < 0.05) compared with the control group.In each feedstuff,after corresponding enzyme treatment,the contents of phytic acid,xylan and β-glucan were significantly lower than those of the control group(P < 0.05).Conclusions: Results showed that bound trace elements in feedstuffs can be released by feed enzymes.It may be necessary to take the trace elements in feedstuffs into account in the actual feed preparation including feed enzymes.
文摘The objective of this study was to develop once-daily metformin hydrochloride sustained-release tablets (MHSRT) and evaluate their in vitro release behavior. MHSRT were prepared by the film coating method. The in vitro drug release rate of MHSRT and the commercial tablets Fortamet? made in the United States of America in water was fitted with zero order kinetic equation, and Ritger-Peppas kinetic equation in 0.1 M HCl and pH 6.8-phosphate buffer, respectively. The similarity factor f2 values of MHSRT in three different dissolution medium were 82, 80 and 74, respectively in comparison with imported Fortamet?, which were all greater than 50. The results of storage-stability showed that MHSRT were stable for at least 6 months under stress condition (40℃ ± 2℃, RH 75% ± 5%). Therefore, in this study, MHSRT were successfully prepared using optimized formulation technologies that meet mass produce. The in vitro release behavior of MHSRT was almost similar to that of imported Fortamet?.
基金State Key Basic Research Development and Programming Project of China (G19980407) and Social Commonweal Research Project of the Ministry of Science and Technology (2002DIA10001).
文摘According to the deficiency of the strain accumulating and releasing curves and the previous models, the strain-accumulating rate of the strain accumulating and releasing model has been deduced based on the G-R relation and the empirical formula between energy release and earthquake magnitude, where the strain-accumulating rate is relative independent of the strain-releasing rate. Five typical areas in Chinese mainland are selected on the basis of the hypothesis on active tectonic block, and small earthquakes from 1970 are imported to calculate the annual strain-accumulating rates considering the completeness of historical seismic data. Having introduced the strain-accumulating rates into the amended model, present strain phases are got. According to the present stages in their own cycles, the future earthquake tendency of each sub-region is discussed.
文摘目的:制备水飞蓟素肠溶聚乳酸-羟基乙酸共聚物(PLGA)纳米粒,并研究其体外释药行为。方法:以羟丙基甲基纤维素邻苯二甲酸酯(HPMCP)为肠溶材料,采用纳米沉淀法制备水飞蓟素肠溶PLGA纳米粒和水飞蓟素PLGA纳米粒,观察其形态,检测其粒径、Zeta电位、包封率、载药量、稳定性、体外释放度(Q)。以粒径、包封率、载药量为指标筛选水飞蓟素肠溶PLGA纳米粒中PLGA-HPMCP质量比。结果:PLGA-HPMCP的最佳质量比为1∶0.25。所制水飞蓟素肠溶PLGA纳米粒和水飞蓟素PLGA纳米粒的粒径分别为224、193 nm,Zeta电位分别为-37.8、-40.7 m V;包封率分别为(74.7±2.2)%、(71.7±2.5)%,载药量分别为(5.39±0.24)%、(5.21±0.22)%;4℃下储存3个月后的渗漏率分别为0.2%、0.5%;人工胃液中Q_(48h)分别为38.6%、70.5%,人工肠液中Q48 h分别为80.2%、73.5%。结论:成功制得水飞蓟素肠溶PLGA纳米粒,其稳定性较好,能有效抑制水飞蓟素在人工胃液中的释放。