Genetic studies have revealed that variants in genes that encode regulators of the complement system are major risk factors for the development of age-related macular degeneration(AMD).The biochemical consequences of ...Genetic studies have revealed that variants in genes that encode regulators of the complement system are major risk factors for the development of age-related macular degeneration(AMD).The biochemical consequences of the common polymorphism in complement factor H(Tyr402His)include increased formation of the membrane attack complex(MAC),which is deposited at the level of the inner choroid and choriocapillaris.Whereas the MAC is normally protective against foreign pathogens,it can also damage resident bystander cells when it is insufficiently regulated.Indeed,human maculas with early AMD show loss of endothelial cells in the choriocapillaris,the principal site of MAC activation.Modeling of MAC injury of choroidal endothelial cells in vitro reveals that these cells are susceptible to cell lysis by the MAC,and that unlysed cells alter their gene expression profile to undergo a pro-angiogenic phenotype that includes increased expression of matrix metalloproteinase-9.Strategies for protecting choriocapillaris endothelial cells from MAC-mediated lysis and for replacing lysed endothelial cells will be discussed.展开更多
Owing to the importance of Sharpless epoxidation reaction in asymmetric synthesis,the regio-and stereoselective opening of the resulting 2, 3-epoxyalcohols has become a topicof current interest.Although many nucleophi...Owing to the importance of Sharpless epoxidation reaction in asymmetric synthesis,the regio-and stereoselective opening of the resulting 2, 3-epoxyalcohols has become a topicof current interest.Although many nucleophiles attack Cin high selectivity under the actionof Ti(OR)4,some of them like halides, azide, and cyanide only show moderate propensity展开更多
The world airport network(WAN) is one of the networked infrastructures that shape today's economic and social activity, so its resilience against incidents affecting the WAN is an important problem. In this paper, ...The world airport network(WAN) is one of the networked infrastructures that shape today's economic and social activity, so its resilience against incidents affecting the WAN is an important problem. In this paper, the robustness of air route networks is extended by defining and testing several heuristics to define selection criteria to detect the critical nodes of the WAN.In addition to heuristics based on genetic algorithms and simulated annealing, custom heuristics based on node damage and node betweenness are defined. The most effective heuristic is a multiattack heuristic combining both custom heuristics. Results obtained are of importance not only for advance in the understanding of the structure of complex networks, but also for critical node detection.展开更多
文摘Genetic studies have revealed that variants in genes that encode regulators of the complement system are major risk factors for the development of age-related macular degeneration(AMD).The biochemical consequences of the common polymorphism in complement factor H(Tyr402His)include increased formation of the membrane attack complex(MAC),which is deposited at the level of the inner choroid and choriocapillaris.Whereas the MAC is normally protective against foreign pathogens,it can also damage resident bystander cells when it is insufficiently regulated.Indeed,human maculas with early AMD show loss of endothelial cells in the choriocapillaris,the principal site of MAC activation.Modeling of MAC injury of choroidal endothelial cells in vitro reveals that these cells are susceptible to cell lysis by the MAC,and that unlysed cells alter their gene expression profile to undergo a pro-angiogenic phenotype that includes increased expression of matrix metalloproteinase-9.Strategies for protecting choriocapillaris endothelial cells from MAC-mediated lysis and for replacing lysed endothelial cells will be discussed.
文摘Owing to the importance of Sharpless epoxidation reaction in asymmetric synthesis,the regio-and stereoselective opening of the resulting 2, 3-epoxyalcohols has become a topicof current interest.Although many nucleophiles attack Cin high selectivity under the actionof Ti(OR)4,some of them like halides, azide, and cyanide only show moderate propensity
文摘The world airport network(WAN) is one of the networked infrastructures that shape today's economic and social activity, so its resilience against incidents affecting the WAN is an important problem. In this paper, the robustness of air route networks is extended by defining and testing several heuristics to define selection criteria to detect the critical nodes of the WAN.In addition to heuristics based on genetic algorithms and simulated annealing, custom heuristics based on node damage and node betweenness are defined. The most effective heuristic is a multiattack heuristic combining both custom heuristics. Results obtained are of importance not only for advance in the understanding of the structure of complex networks, but also for critical node detection.