Ten trace and heavy metals （Fe, Mn, Ni, Zn, Cu, Cd, As, Co, Cr and V） were analysed in sediments collected from nine stations at the Tema Port of Ghana, during the dry and wet seasons. Analysis of samples was done u...Ten trace and heavy metals （Fe, Mn, Ni, Zn, Cu, Cd, As, Co, Cr and V） were analysed in sediments collected from nine stations at the Tema Port of Ghana, during the dry and wet seasons. Analysis of samples was done using INAA （instrumental neutron activation analysis） for Mn, V, Cu, As and Cd, and AAS （atomic absorption spectrophotometry） for Fe, Cr, Zn, Ni and Co. The concentrations of metals in sediments followed the orders Fe 〉 V〉 Mn 〉 Cd 〉 Ni 〉 Zn 〉 Cu 〉As, for the dry season and Fe 〉 V 〉 Ni 〉 Cu 〉 Zn 〉 Mn 〉 Cd 〉As, for the wet season. Concentrations of Co and Cr were below detection limit, whiles Cu, Cd and Ni were found to be above the TELs （threshold effect levels） of NOAA＇s （National Oceanic and Atmospheric Administration＇s） SQuiRTs （screening quick reference tables） at most sites. Estimated enrichment factors for individual metals showed very high contamination of the port＇s sediments, with Cd occurring at all sites, and Cu, As, V and Ni occurring at some sites for both dry and wet seasons. Although sediments from the Tema Port were highly enriched with Cd, Cu, Ni and V above natural background levels, the overall PLI （pollution load index） per sampling station considering background values of the analysed elements indicated that metal pollution in the port＇s sediment is below 1, indicating relatively unpolluted sediment.展开更多
Research was done with the objective of evaluating the quality of water supplied to the potable water system in Hidalgo Del Parral, which comes from two main supply sources： wells from ＂Valle del Verano＂, which pro...Research was done with the objective of evaluating the quality of water supplied to the potable water system in Hidalgo Del Parral, which comes from two main supply sources： wells from ＂Valle del Verano＂, which provide water to the east side of the city, and the Water Treatment Plant, which receives water from different mines and supplies the west side of the city. When this plant is overcome on its capacity of treatment, a part of the water from the mines is fed directly to the northwest part of the city. The metals lead （Pb）, chromium （Cr）, cadmium （Cd）, zinc （Zn）, and arsenic （As） were analyzed by atomic absorption （AA） technique, based on the United States Environmental Protection Agency （EPA） Method 7000B （Revision 2, February 2007）. The digestion process was done according to the guidelines established in Method NMX-AA-051-SCFI-2001, Analysis of Water-Determination of Metals by Atomic Absorption, developed by the National Standardization Technical Committee for Environmental Protection （Mexico）. The samples were collected from the following points： 13 wells and 2 re-pumping stations of ＂Valle del Verano＂, the inlet and outlet of the Water Treatment Plant, and domestic faucets. The east side of the city, supplied by the wells of ＂Valle del Verano＂, is metal-pollution free. The water that comes from the mines contains high concentrations of As, Zn, Cd and Pb, with levels that can get to 0.12, 32.6, 0.26 and 3.5 mg/L, respectively. This water pollution generated by mining can be concluded from the high levels found in the domestic samples in which, for several points, the concentrations exceed the parameters set by the current guideline. According to the results, it is vital to set a plan of remediation for the water that comes from the mines, because there is a great risk for health in the consumotion of this water.展开更多
Hesperetin,an abundant bioactive component of citrus fruits,is poorly water-soluble,resulting in low oral bioavailability.We developed new formulations to improve the water solubility,antioxidant activity,and oral abs...Hesperetin,an abundant bioactive component of citrus fruits,is poorly water-soluble,resulting in low oral bioavailability.We developed new formulations to improve the water solubility,antioxidant activity,and oral absorption of hesperetin.Two nano-based formulations were developed,namely hesperetin-TPGS(D-α-tocopheryl polyethylene glycol 1000 succinate)micelles and hesperetin-phosphatidylcholine(PC)complexes.These two formulations were prepared by a simple technique called solvent dispersion,using US Food and Drug Administration(FDA)-approved excipients for drugs.Differential scanning calorimetry(DSC)and dynamic light scattering(DLS)were used to characterize the formulations’physical properties.Cytotoxicity analysis,cellular antioxidant activity assay,and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations.The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility,which increased to 21.5-and 20.7-fold,respectively.The hesperetin-TPGS micelles had a small particle size of 26.19 nm,whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm.In addition,the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2-and 3.9-fold,respectively.Importantly,the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration(Cmax)from 2.64μg/mL to 20.67 and 33.09μg/mL and also increased the area under the concentration–time curve of hesperetin after oral administration to 16.2-and 18.0-fold,respectively.The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin,indicating these formulations’potential applications in drugs and healthcare products.展开更多
文摘Ten trace and heavy metals （Fe, Mn, Ni, Zn, Cu, Cd, As, Co, Cr and V） were analysed in sediments collected from nine stations at the Tema Port of Ghana, during the dry and wet seasons. Analysis of samples was done using INAA （instrumental neutron activation analysis） for Mn, V, Cu, As and Cd, and AAS （atomic absorption spectrophotometry） for Fe, Cr, Zn, Ni and Co. The concentrations of metals in sediments followed the orders Fe 〉 V〉 Mn 〉 Cd 〉 Ni 〉 Zn 〉 Cu 〉As, for the dry season and Fe 〉 V 〉 Ni 〉 Cu 〉 Zn 〉 Mn 〉 Cd 〉As, for the wet season. Concentrations of Co and Cr were below detection limit, whiles Cu, Cd and Ni were found to be above the TELs （threshold effect levels） of NOAA＇s （National Oceanic and Atmospheric Administration＇s） SQuiRTs （screening quick reference tables） at most sites. Estimated enrichment factors for individual metals showed very high contamination of the port＇s sediments, with Cd occurring at all sites, and Cu, As, V and Ni occurring at some sites for both dry and wet seasons. Although sediments from the Tema Port were highly enriched with Cd, Cu, Ni and V above natural background levels, the overall PLI （pollution load index） per sampling station considering background values of the analysed elements indicated that metal pollution in the port＇s sediment is below 1, indicating relatively unpolluted sediment.
文摘Research was done with the objective of evaluating the quality of water supplied to the potable water system in Hidalgo Del Parral, which comes from two main supply sources： wells from ＂Valle del Verano＂, which provide water to the east side of the city, and the Water Treatment Plant, which receives water from different mines and supplies the west side of the city. When this plant is overcome on its capacity of treatment, a part of the water from the mines is fed directly to the northwest part of the city. The metals lead （Pb）, chromium （Cr）, cadmium （Cd）, zinc （Zn）, and arsenic （As） were analyzed by atomic absorption （AA） technique, based on the United States Environmental Protection Agency （EPA） Method 7000B （Revision 2, February 2007）. The digestion process was done according to the guidelines established in Method NMX-AA-051-SCFI-2001, Analysis of Water-Determination of Metals by Atomic Absorption, developed by the National Standardization Technical Committee for Environmental Protection （Mexico）. The samples were collected from the following points： 13 wells and 2 re-pumping stations of ＂Valle del Verano＂, the inlet and outlet of the Water Treatment Plant, and domestic faucets. The east side of the city, supplied by the wells of ＂Valle del Verano＂, is metal-pollution free. The water that comes from the mines contains high concentrations of As, Zn, Cd and Pb, with levels that can get to 0.12, 32.6, 0.26 and 3.5 mg/L, respectively. This water pollution generated by mining can be concluded from the high levels found in the domestic samples in which, for several points, the concentrations exceed the parameters set by the current guideline. According to the results, it is vital to set a plan of remediation for the water that comes from the mines, because there is a great risk for health in the consumotion of this water.
基金Project supported by the National Natural Science Foundation of China(Nos.51773176,51522304,and U1501243)the Natural Science Foundation of Zhejiang Province(No.LY17H300002),China
文摘Hesperetin,an abundant bioactive component of citrus fruits,is poorly water-soluble,resulting in low oral bioavailability.We developed new formulations to improve the water solubility,antioxidant activity,and oral absorption of hesperetin.Two nano-based formulations were developed,namely hesperetin-TPGS(D-α-tocopheryl polyethylene glycol 1000 succinate)micelles and hesperetin-phosphatidylcholine(PC)complexes.These two formulations were prepared by a simple technique called solvent dispersion,using US Food and Drug Administration(FDA)-approved excipients for drugs.Differential scanning calorimetry(DSC)and dynamic light scattering(DLS)were used to characterize the formulations’physical properties.Cytotoxicity analysis,cellular antioxidant activity assay,and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations.The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility,which increased to 21.5-and 20.7-fold,respectively.The hesperetin-TPGS micelles had a small particle size of 26.19 nm,whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm.In addition,the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2-and 3.9-fold,respectively.Importantly,the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration(Cmax)from 2.64μg/mL to 20.67 and 33.09μg/mL and also increased the area under the concentration–time curve of hesperetin after oral administration to 16.2-and 18.0-fold,respectively.The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin,indicating these formulations’potential applications in drugs and healthcare products.
