As one of the seaweed polysaccharide, agarose has received much attention because of its biocompatibility. However, its application in biomedical field was limited with its biological inertia. Modification with some f...As one of the seaweed polysaccharide, agarose has received much attention because of its biocompatibility. However, its application in biomedical field was limited with its biological inertia. Modification with some functional groups is needed to obtain agarose derivatives with biological activity and expand its applications. Consequently, agarose was sulfated with chlorosulfonic acid-pyridine with formamide as dispersing agent. The orthogonal test result showed that the optimal reaction condition was the reaction time being 4 h, the reaction temperature 65 ℃ and the ratio of chlorosulfonic acid to agarose 1-4（mL/g）. Two kinds of the insoluble agarose sulfate （below 37 ℃） were synthesized with degree of substitution （DS） being 0.17 and 0.43 respectively. Infrared spectroscopy （IR） and tac nuclear magnetic resonance （13C-NMR） spectroscopy results proved that C3_6 in agarose was sulfated. Their hydrophobic property and BSA adsorption capacity rose with increasing DS, while the adsorption of lib was reduced. The anti-clotting properties of agarose sulfate were significantly improved, and agarose sulfate could protect red blood cells from deformation after adsorption of BSA. These findings demonstrate that the cold-water insoluble agarose sulfate has a promise for applications as heoarin-like material in anticoagulation or endothelial re^enera＇Lion scaffold.展开更多
For a long time, imports were always an important component part of China’s auto market, an important means for regulating the balance of supply and demand on the domestic market. But along with the rapid development...For a long time, imports were always an important component part of China’s auto market, an important means for regulating the balance of supply and demand on the domestic market. But along with the rapid development of the domestic auto industry, the position and action of automobile imports on the do-展开更多
In the 1980s, China’s auto market saw three dramatic fluctuations. Since the beginning of the 1990s, the market, as a whole, has become calm and stable without any major changes, though it has never evaded occasional...In the 1980s, China’s auto market saw three dramatic fluctuations. Since the beginning of the 1990s, the market, as a whole, has become calm and stable without any major changes, though it has never evaded occasional rises and fails. The pattern of demand on the market has been generally set and clear, and has begun to grow steadily. In view of the present situation, two major categories of vehicles—office-use and business or service use cars and trucks—have long been in demand on the market, almost dominat-展开更多
基金863 High-tech Plan (No. 2007AA09Z436)NNSFC(No. 31070853)+2 种基金Guangdong Technology Plan (No. 2010B031100015)Guangzhou Technology Plan (No. 2010-EJ0041)"12-5" National Tech Program
文摘As one of the seaweed polysaccharide, agarose has received much attention because of its biocompatibility. However, its application in biomedical field was limited with its biological inertia. Modification with some functional groups is needed to obtain agarose derivatives with biological activity and expand its applications. Consequently, agarose was sulfated with chlorosulfonic acid-pyridine with formamide as dispersing agent. The orthogonal test result showed that the optimal reaction condition was the reaction time being 4 h, the reaction temperature 65 ℃ and the ratio of chlorosulfonic acid to agarose 1-4（mL/g）. Two kinds of the insoluble agarose sulfate （below 37 ℃） were synthesized with degree of substitution （DS） being 0.17 and 0.43 respectively. Infrared spectroscopy （IR） and tac nuclear magnetic resonance （13C-NMR） spectroscopy results proved that C3_6 in agarose was sulfated. Their hydrophobic property and BSA adsorption capacity rose with increasing DS, while the adsorption of lib was reduced. The anti-clotting properties of agarose sulfate were significantly improved, and agarose sulfate could protect red blood cells from deformation after adsorption of BSA. These findings demonstrate that the cold-water insoluble agarose sulfate has a promise for applications as heoarin-like material in anticoagulation or endothelial re^enera＇Lion scaffold.
文摘For a long time, imports were always an important component part of China’s auto market, an important means for regulating the balance of supply and demand on the domestic market. But along with the rapid development of the domestic auto industry, the position and action of automobile imports on the do-
文摘In the 1980s, China’s auto market saw three dramatic fluctuations. Since the beginning of the 1990s, the market, as a whole, has become calm and stable without any major changes, though it has never evaded occasional rises and fails. The pattern of demand on the market has been generally set and clear, and has begun to grow steadily. In view of the present situation, two major categories of vehicles—office-use and business or service use cars and trucks—have long been in demand on the market, almost dominat-
