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Air quality is one of the important conditions for a better residence life in the populated urban area and it is closed related to the micro-atmospheric environment. Atmospheric environment is controlled by air motion with multi-scales in the city, while air flows in the residence area are of micro-scale atmospheric motion. This paper introduces a modern numerical simulation method, i.e. large eddy simulation (LES), for studying micro-atmospheric flows in the city residence area. For the complex flow features in the residence area, the proper application of LES is studied and various numerical methods are compared in order to investigate their effects on the prediction accuracy of micro-atmospheric flows, for instance, roughness elements and immersed boundary method for complex terrain, different subgrid models and so on. The wind field (including turbulence properties) and contaminant dispersion are computed by the proposed method for a model and a realistic residence area, and the numerical results are in good agreement with the experimental measurements. micro-atmospheric environment, turbulence dispersion, large eddy simulationAir quality is a prerequisite for people's daily life. During the process of urbanization around the world and improvement of living standard, air quality in cities is drawing more and more attention. The increasing requirements of healthy and comfortable life call for more scientific city planning, while traditional empirical prediction and engineering estimation methods for air quality may not provide satisfactory results. With the improving of computer resources, computational fluid dynamics (CFD) becomes an economical and effective tool for environmental flow problems. However, for precise prediction of the turbulent flow in the urban residence area, further research is needed on the flow mechanism and numerical method.The atmospheric flows in an urban residence area are the sub-system of city atmospheric en-

The skin is a multi‐layered structure composed of the epidermis, dermis and hypodermis. The epidermis originates entirely from the ectoderm, whereas the dermis originates from various germ layers depending on its anatomical location; thus, there are different developmental patterns of the skin. Although the regulatory mechanisms of epidermal formation are well understood, mechanisms regulating dermis development are not clear owing to the complex origin. It has been shown that several morphogenetic pathways regulate dermis development. Of these, transforming growth factor‐β (TGF‐β) and fibroblast growth factor (FGF) signalling pathways are the main modulators regulating skin cell induction, fate decision, migration and differentiation. Recently, the successful generation of human skin by modulating TGF‐β and FGF signals further demonstrated the irreplaceable roles of these pathways in skin regeneration. This review provides evidence of the role of TGF‐β and FGF signalling pathways in the development of different skin layers, especially the disparate dermis of different body regions. This review also provides new perspectives on the distinct developmental patterns of skin and explores new ideas for clinical applications in the future.

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