Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a ^(41)Ca tracer technique ...Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a ^(41)Ca tracer technique in SD rats was conducted to measure the endogenous fecal calcium and true absorption of calcium. Apparent absorption of calcium was measured as a control to the endogenous calcium labeling experiment. These results show that by using ^(41)Ca labeled endogenous calcium in vivo, researchers could obtain the true calcium absorption data without extrinsic labeling. Therefore, the method was not affected by the chemical structure or type of calcium supplement and might be used in evaluating the absorptivity of marketed calcium supplements.展开更多
When the thermal environment is under heated conditions, short-wavelength solar radiation shows a strong influence on the human body and the heat is accumulated in the human body. In order to demonstrate the effect of...When the thermal environment is under heated conditions, short-wavelength solar radiation shows a strong influence on the human body and the heat is accumulated in the human body. In order to demonstrate the effect of the short-wavelength solar radiation absorptivity of clothing on physiological temperature in an outdoor space, the relationship between the thermal environment evaluation index, ETFe, and the thermal sensory perceptions of the human body was investigated. A significant temperature difference of 2.7°C was shown for an ETFe that was thermally neutral (neither hot nor cold). The effect of short-wavelength solar radiation absorptivity was strongly apparent in ETFe when direct solar radiation was strong and in warmer outdoor spaces. In an outdoor space where the effect of the sky factor and albedo was strong, the setting of the short-wavelength solar radiation absorptivity was demonstrated to greatly impact the estimation of perceived and physiological temperature. When interviewing subjects on clothing in an outdoor space, it is essential to obtain the hue of clothing.展开更多
Choosing two different elements of rare earth, the absorptivity of them on copper and its alloys were researched from the category of rare earth, melting point, adding methods, casting temperature, time of heat preser...Choosing two different elements of rare earth, the absorptivity of them on copper and its alloys were researched from the category of rare earth, melting point, adding methods, casting temperature, time of heat preservation, quantity of rare earth additives etc. The laws of affecting the absorptivity are found through the research. The distributing of rare earth, existent state and the formed compounds on copper and its alloys were observed in the casting state. The absorptivities of rare earth on copper and its alloys were analyzed.展开更多
Background:Traditional Chinese medicine involves complex ingredients and mixtures of ingredients that often exhibit low bioavailability,and excipients are often lacking to increase the absorption-enhancing effects.Thi...Background:Traditional Chinese medicine involves complex ingredients and mixtures of ingredients that often exhibit low bioavailability,and excipients are often lacking to increase the absorption-enhancing effects.This study modified the generation 4 polyamidoamine dendrimer with polyethylene glycol of different molecular weights(5000,2000,1000)to form a series of polyamidoamine-co-polyethylene glycol(PAMAM-co-PEG)as a novel class of oral absorption enhancers.Evodiamine,the major alkaloid found in the traditional Chinese medicine Wu Zhu Yu(Fructus Evodiae),was used as a model drug to verify the absorption-enhancing effects and the safety of this alkaloid.Methods:This study utilized the solubility determination method documented in the Pharmacopoeia of the People’s Republic of China(2015 edition)and the D0 values recommended in the US FDA guidelines to comprehensively evaluate the solubility of evodiamine.The permeability of evodiamine was assessed using the apparent permeability coefficient in experiments based on in vitro cell models.Multiple aspects of the biological safety of PAMAM-co-PEG were explored using the MTT assay,LDH assay,and total protein release of the rat intestinal tract.Moreover,the absorption-enhancing effects of PAMAM-co-PEG at different molecular weights on evodiamine were verified via the use of in vitro cell models and in vivo intestinal loop circulation experiments with rats.Results:Evodiamine exhibited low solubility and permeability and was classified into class IV compounds using the biopharmaceutical classification system.PAMAM-co-PEG 2000 demonstrated improvement in the biosafety and absorption-enhancement effect of evodiamine at a specific concentration.This study showed that 0.05%(w/v)of PAMAM-co-PEG 2000 increased the cumulative penetration of evodiamine via cell transport by 1.32 times,and 0.10%(w/v)of PAMAM-co-PEG 2000 increased the area under curve value of evodiamine by 1.31 times.Conclusion:Evodiamine possesses low solubility and permeability and leads to poor oral bioavailability and a certain degree of cytotoxicity.PAMAM-co-PEG 2000 was found to be a potentially safe and efficient oral absorption enhancer.The results of this study might create a foundation for the development of novel excipients suitable for the complex active ingredients of traditional Chinese medicine.展开更多
The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, flexural strength, and notched impact strength of polytetrafluoroethylene/polyamide 6 (PTFE/PA6) and polytetrafluoroethyle...The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, flexural strength, and notched impact strength of polytetrafluoroethylene/polyamide 6 (PTFE/PA6) and polytetrafluoroethylene/polyamide 66 (PTFE/PA66) blends were investigated by water immersion test, uniaxial tensile test, three-point test, and Charpy impact fracture test. The water-absorptivity in the blend decreases with increasing PTFE content, which indicates that the PTFE phase restrains the polyamide phase from water absorption. For water-free blends, the addition of PTFE causes a reduction in tensile strength, while for water-absorbed PTFE/PA6 blends, the tensile strength increases with increasing PTFE. Simultaneously, the absorbed water improves the elongation, but results in a notable reduction in flexural strength of the blends. Although the addition of PTFE causes a reduction in notched impact strength of the blends, as compared to pure polyamide, the absorbed water has little effects on the notched impact strength of the blends. Finally, the effects of temperature and loading frequency on complex viscosity parameters of PTFE/PA6 and PTFE/PA66 melts were tested. It is found that the complex viscosity of PTFE/PA6 melt is reversed with increasing temperature and shear velocity, but that of PTFE/PA66 melt increases approximately in exponential form with increasing temperature. To fill polyamide with suitable mass percentage of PTFE can effectively reduce the viscosity of blend, and as a result, the molding and processing properties are improved.展开更多
基金supported by the National Nature Science Foundation of China(No.11375272)
文摘Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a ^(41)Ca tracer technique in SD rats was conducted to measure the endogenous fecal calcium and true absorption of calcium. Apparent absorption of calcium was measured as a control to the endogenous calcium labeling experiment. These results show that by using ^(41)Ca labeled endogenous calcium in vivo, researchers could obtain the true calcium absorption data without extrinsic labeling. Therefore, the method was not affected by the chemical structure or type of calcium supplement and might be used in evaluating the absorptivity of marketed calcium supplements.
文摘When the thermal environment is under heated conditions, short-wavelength solar radiation shows a strong influence on the human body and the heat is accumulated in the human body. In order to demonstrate the effect of the short-wavelength solar radiation absorptivity of clothing on physiological temperature in an outdoor space, the relationship between the thermal environment evaluation index, ETFe, and the thermal sensory perceptions of the human body was investigated. A significant temperature difference of 2.7°C was shown for an ETFe that was thermally neutral (neither hot nor cold). The effect of short-wavelength solar radiation absorptivity was strongly apparent in ETFe when direct solar radiation was strong and in warmer outdoor spaces. In an outdoor space where the effect of the sky factor and albedo was strong, the setting of the short-wavelength solar radiation absorptivity was demonstrated to greatly impact the estimation of perceived and physiological temperature. When interviewing subjects on clothing in an outdoor space, it is essential to obtain the hue of clothing.
文摘Choosing two different elements of rare earth, the absorptivity of them on copper and its alloys were researched from the category of rare earth, melting point, adding methods, casting temperature, time of heat preservation, quantity of rare earth additives etc. The laws of affecting the absorptivity are found through the research. The distributing of rare earth, existent state and the formed compounds on copper and its alloys were observed in the casting state. The absorptivities of rare earth on copper and its alloys were analyzed.
基金This research was funded by National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2015ZX09501005)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2016-I2M-1-012).
文摘Background:Traditional Chinese medicine involves complex ingredients and mixtures of ingredients that often exhibit low bioavailability,and excipients are often lacking to increase the absorption-enhancing effects.This study modified the generation 4 polyamidoamine dendrimer with polyethylene glycol of different molecular weights(5000,2000,1000)to form a series of polyamidoamine-co-polyethylene glycol(PAMAM-co-PEG)as a novel class of oral absorption enhancers.Evodiamine,the major alkaloid found in the traditional Chinese medicine Wu Zhu Yu(Fructus Evodiae),was used as a model drug to verify the absorption-enhancing effects and the safety of this alkaloid.Methods:This study utilized the solubility determination method documented in the Pharmacopoeia of the People’s Republic of China(2015 edition)and the D0 values recommended in the US FDA guidelines to comprehensively evaluate the solubility of evodiamine.The permeability of evodiamine was assessed using the apparent permeability coefficient in experiments based on in vitro cell models.Multiple aspects of the biological safety of PAMAM-co-PEG were explored using the MTT assay,LDH assay,and total protein release of the rat intestinal tract.Moreover,the absorption-enhancing effects of PAMAM-co-PEG at different molecular weights on evodiamine were verified via the use of in vitro cell models and in vivo intestinal loop circulation experiments with rats.Results:Evodiamine exhibited low solubility and permeability and was classified into class IV compounds using the biopharmaceutical classification system.PAMAM-co-PEG 2000 demonstrated improvement in the biosafety and absorption-enhancement effect of evodiamine at a specific concentration.This study showed that 0.05%(w/v)of PAMAM-co-PEG 2000 increased the cumulative penetration of evodiamine via cell transport by 1.32 times,and 0.10%(w/v)of PAMAM-co-PEG 2000 increased the area under curve value of evodiamine by 1.31 times.Conclusion:Evodiamine possesses low solubility and permeability and leads to poor oral bioavailability and a certain degree of cytotoxicity.PAMAM-co-PEG 2000 was found to be a potentially safe and efficient oral absorption enhancer.The results of this study might create a foundation for the development of novel excipients suitable for the complex active ingredients of traditional Chinese medicine.
基金This work was supported by the National Natural Science Foundation of China(No.50374038,50574040)Specialized Research Fund for the Doctoral Program of Higher Education(20030251002)+1 种基金Key Project of the Ministry of Education(03071)by the Department of Science and Technology Shanghai(045407017).
基金Prqject(10572123) supported by the National Natural Science Foundation of China Project(05JJ30014) supported by the Natural Science Foundation of Hunan Province, China Project(05C100) supported by the Scientific Research Fund of Education Department of Hunan Province, China
文摘The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, flexural strength, and notched impact strength of polytetrafluoroethylene/polyamide 6 (PTFE/PA6) and polytetrafluoroethylene/polyamide 66 (PTFE/PA66) blends were investigated by water immersion test, uniaxial tensile test, three-point test, and Charpy impact fracture test. The water-absorptivity in the blend decreases with increasing PTFE content, which indicates that the PTFE phase restrains the polyamide phase from water absorption. For water-free blends, the addition of PTFE causes a reduction in tensile strength, while for water-absorbed PTFE/PA6 blends, the tensile strength increases with increasing PTFE. Simultaneously, the absorbed water improves the elongation, but results in a notable reduction in flexural strength of the blends. Although the addition of PTFE causes a reduction in notched impact strength of the blends, as compared to pure polyamide, the absorbed water has little effects on the notched impact strength of the blends. Finally, the effects of temperature and loading frequency on complex viscosity parameters of PTFE/PA6 and PTFE/PA66 melts were tested. It is found that the complex viscosity of PTFE/PA6 melt is reversed with increasing temperature and shear velocity, but that of PTFE/PA66 melt increases approximately in exponential form with increasing temperature. To fill polyamide with suitable mass percentage of PTFE can effectively reduce the viscosity of blend, and as a result, the molding and processing properties are improved.
