Metabolism such as Cairo evolves rabidly, to transform existing urban spaces. The result of transformation process may lead to the loss of the original space qualities. Opera and Ataba squares are junction space which...Metabolism such as Cairo evolves rabidly, to transform existing urban spaces. The result of transformation process may lead to the loss of the original space qualities. Opera and Ataba squares are junction space which is one of these urban spaces that meanwhile is suffering from this process. This junction space is between two unique urban structures Fatima Cairo and Down town Cairo. This urban structure needs to be a grand civic expression of the 19th century urban system with the new energies of the functionalist city. This Gordian knot of elevated highways, congested surface roads, extensive automobile parking and sprawling informal markets will be integrated into a new open space system that optimizes the city＇s intensified energies. This paper discusses urban structure transformation of the junction space urban structure timeline. Ending with a proposal finally transforms this space into a sustainable urban development.展开更多
Natural products are often secondary metabolites in living organisms with a wide variety of biological activities. The diversification of their structures, aiming to the search for biologically active small molecules ...Natural products are often secondary metabolites in living organisms with a wide variety of biological activities. The diversification of their structures, aiming to the search for biologically active small molecules by expanding chemical and functional spaces, is a major area of current interest in synthetic chemistry. However, developing synthetic accessibility and efficiency often faces challenges associated with structural complexity. Synthetic biology has recently emerged and is promising to accomplish complex molecules; by contrast, the application to structural diversification of natural products relies on the understanding, development and utilization of compatible biosynthetic machinery. Here, we review the strategies primarily concerning the artificial evolution of microbial natural products whose biosynthesis features template enzymology, including ribosomaUy synthesized and post-translationally modified peptides as well as the assembly line-resultant polyketides, non-ribosomal peptides and hybrids. The establishment of these approaches largely facilitates the expansion of the molecular diversity and utility through bioengineering at different stages/levels of biosynthetic pathways.展开更多
We consider the process of hemodialysis performed by means of a hollow fiber dialyzer with a special focus on the dynamics of the light solutes （including metabolic waste products） through the porous fibers membrane...We consider the process of hemodialysis performed by means of a hollow fiber dialyzer with a special focus on the dynamics of the light solutes （including metabolic waste products） through the porous fibers membrane. The model we illustrate here completes the one formulated in a previous paper in which solutes concentrations in the dialyzate were neglected. Exploiting the large difference between the characteristic time of the processes in the machine and the relaxation time to equilibrium in the body, we confine our study to the case of constant input data in order to emphasize the role of the solute transport mechanisms. Numerical solutions show that diffusion is dominant at the early stage of filtration.展开更多
文摘Metabolism such as Cairo evolves rabidly, to transform existing urban spaces. The result of transformation process may lead to the loss of the original space qualities. Opera and Ataba squares are junction space which is one of these urban spaces that meanwhile is suffering from this process. This junction space is between two unique urban structures Fatima Cairo and Down town Cairo. This urban structure needs to be a grand civic expression of the 19th century urban system with the new energies of the functionalist city. This Gordian knot of elevated highways, congested surface roads, extensive automobile parking and sprawling informal markets will be integrated into a new open space system that optimizes the city＇s intensified energies. This paper discusses urban structure transformation of the junction space urban structure timeline. Ending with a proposal finally transforms this space into a sustainable urban development.
基金supported by the National Natural Science Foundation of China (81402831, 21520102004, 31430005, 21472231)Science and Technology Commission of Shanghai Municipality (Shanghai, China) (14JC1407700, 15JC1400400) of China
文摘Natural products are often secondary metabolites in living organisms with a wide variety of biological activities. The diversification of their structures, aiming to the search for biologically active small molecules by expanding chemical and functional spaces, is a major area of current interest in synthetic chemistry. However, developing synthetic accessibility and efficiency often faces challenges associated with structural complexity. Synthetic biology has recently emerged and is promising to accomplish complex molecules; by contrast, the application to structural diversification of natural products relies on the understanding, development and utilization of compatible biosynthetic machinery. Here, we review the strategies primarily concerning the artificial evolution of microbial natural products whose biosynthesis features template enzymology, including ribosomaUy synthesized and post-translationally modified peptides as well as the assembly line-resultant polyketides, non-ribosomal peptides and hybrids. The establishment of these approaches largely facilitates the expansion of the molecular diversity and utility through bioengineering at different stages/levels of biosynthetic pathways.
文摘We consider the process of hemodialysis performed by means of a hollow fiber dialyzer with a special focus on the dynamics of the light solutes （including metabolic waste products） through the porous fibers membrane. The model we illustrate here completes the one formulated in a previous paper in which solutes concentrations in the dialyzate were neglected. Exploiting the large difference between the characteristic time of the processes in the machine and the relaxation time to equilibrium in the body, we confine our study to the case of constant input data in order to emphasize the role of the solute transport mechanisms. Numerical solutions show that diffusion is dominant at the early stage of filtration.
