Concentrations of 8 heavy metals: cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony (Sb) and tin (Sn) were examined in 3 species of bivalves (Perna viridis, Crassostrea rivularis ...Concentrations of 8 heavy metals: cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony (Sb) and tin (Sn) were examined in 3 species of bivalves (Perna viridis, Crassostrea rivularis and Ruditapes philippinarum) collected from 25 sites along the Pearl River Delta coastal waters in the South China Sea from July to August 1996. In general, Cd, Cu, Zn and Sn concentrations in the three bivalve species collected from the Estuarine Zone were significantly higher than those collected from the Western and Eastern Zones of the Pearl River Delta, which are related to the existence of various anthropogenic activities in the catchment of the Pearl River Delta. The Western Estuarine Zone is mainly impacted by Cr, Ni and Cu contamination. In Victoria Harbor, heavy metal contamination is mainly due to Cu and Pb. Cd, Cu and Zn concentrations in oysters were significantly higher than those in mussels and clams. This could be explained by the fact that oysters live mainly in the Estuarine Zone of the Pearl River Delta which receives most of the polluting discharges from the catchment of the Delta. During turbid condition, heavy metals(soluble or adsorbed on suspended particulates) discharged from the Delta are filtered from the water column and subsequently accumulated into the soft body tissues of oysters. Heavy metal concentrations in the three bivalve species were compared with the maximum permissible levels of heavy metals in seafood regulated by the Public Health and Municipal Services Ordinance, Laws of Hong Kong, and it was revealed that Cd and Cr concentrations in the three bivalve species exceeded the upper limits. At certain hotspots in the Delta, the maximum acceptable daily load for Cd was also exceeded.展开更多
Uncontrolled bleeding and infection can cause significant increases in mortalities.Hydrogel sealants have attracted extensive attention for their ability to control bleeding.However,because interfacial water is a form...Uncontrolled bleeding and infection can cause significant increases in mortalities.Hydrogel sealants have attracted extensive attention for their ability to control bleeding.However,because interfacial water is a formidable barrier to strong surface bonding,a challenge remains in finding a product that offers robust tissue adhesion combined with anti-infection properties.Inspired by the strong adhesive mechanism of biofilm and mussels,we report a novel dual bionic adhesive hydrogel(DBAH)based on chitosan grafted with methacrylate(CS-MA),dopamine(DA),and N-hydroxymethyl acrylamide(NMA)via a facile radical polymerization process.CS-MA and DA were simultaneously included in the adhesive polymer for imitating the two key adhesive components:polysaccharide intercellular adhesin(PIA)of staphylococci biofilm and 3,4-dihydroxy-L-phenylalanine(Dopa)of mussel foot protein,respectively.DBAH presented strong adhesion at 34 kPa even upon three cycles of full immersion in water and was able to withstand up to 168 mm Hg blood pressure,which is significantly higher than the 60–160 mm Hg measured in most clinical settings.Most importantly,these hydrogels presented outstanding hemostatic capability under wet and dynamic in vivo movements while displaying excellent antibacterial properties and biocompatibility.Therefore,DBAH represents a promising class of biomaterials for high-efficiency hemostasis and wound healing.展开更多
文摘Concentrations of 8 heavy metals: cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony (Sb) and tin (Sn) were examined in 3 species of bivalves (Perna viridis, Crassostrea rivularis and Ruditapes philippinarum) collected from 25 sites along the Pearl River Delta coastal waters in the South China Sea from July to August 1996. In general, Cd, Cu, Zn and Sn concentrations in the three bivalve species collected from the Estuarine Zone were significantly higher than those collected from the Western and Eastern Zones of the Pearl River Delta, which are related to the existence of various anthropogenic activities in the catchment of the Pearl River Delta. The Western Estuarine Zone is mainly impacted by Cr, Ni and Cu contamination. In Victoria Harbor, heavy metal contamination is mainly due to Cu and Pb. Cd, Cu and Zn concentrations in oysters were significantly higher than those in mussels and clams. This could be explained by the fact that oysters live mainly in the Estuarine Zone of the Pearl River Delta which receives most of the polluting discharges from the catchment of the Delta. During turbid condition, heavy metals(soluble or adsorbed on suspended particulates) discharged from the Delta are filtered from the water column and subsequently accumulated into the soft body tissues of oysters. Heavy metal concentrations in the three bivalve species were compared with the maximum permissible levels of heavy metals in seafood regulated by the Public Health and Municipal Services Ordinance, Laws of Hong Kong, and it was revealed that Cd and Cr concentrations in the three bivalve species exceeded the upper limits. At certain hotspots in the Delta, the maximum acceptable daily load for Cd was also exceeded.
基金supported by the National Key R&D Program of China(2019YFA0905203)National Natural Science Foundation of China(51703095)+4 种基金Natural Science Foundation of Jiangsu Province(BK20171010)the State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201905)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(XTB1804)Jiangsu Agricultural Science and Technology Innovation Fund(CX(19)3115)the China Postdoctoral Science Foundation(2019M661814).
文摘Uncontrolled bleeding and infection can cause significant increases in mortalities.Hydrogel sealants have attracted extensive attention for their ability to control bleeding.However,because interfacial water is a formidable barrier to strong surface bonding,a challenge remains in finding a product that offers robust tissue adhesion combined with anti-infection properties.Inspired by the strong adhesive mechanism of biofilm and mussels,we report a novel dual bionic adhesive hydrogel(DBAH)based on chitosan grafted with methacrylate(CS-MA),dopamine(DA),and N-hydroxymethyl acrylamide(NMA)via a facile radical polymerization process.CS-MA and DA were simultaneously included in the adhesive polymer for imitating the two key adhesive components:polysaccharide intercellular adhesin(PIA)of staphylococci biofilm and 3,4-dihydroxy-L-phenylalanine(Dopa)of mussel foot protein,respectively.DBAH presented strong adhesion at 34 kPa even upon three cycles of full immersion in water and was able to withstand up to 168 mm Hg blood pressure,which is significantly higher than the 60–160 mm Hg measured in most clinical settings.Most importantly,these hydrogels presented outstanding hemostatic capability under wet and dynamic in vivo movements while displaying excellent antibacterial properties and biocompatibility.Therefore,DBAH represents a promising class of biomaterials for high-efficiency hemostasis and wound healing.
