Climate change and urbanization have increasingly exacerbated the threat of storm floods to urban metro systems. To enhance the flood emergency management of metro systems, this study proposes a two-stage stochastic o...
Climate change and urbanization have increasingly exacerbated the threat of storm floods to urban metro systems. To enhance the flood emergency management of metro systems, this study proposes a two-stage stochastic optimization model. In this model, the closure decisions for risky stations and the allocation of flood control resources are implemented before and during the rainstorm, respectively, to maximize the average utility of passengers in the metro network. A case study on the Shanghai metro system is conducted to demonstrate the applicability and effectiveness of the proposed model. The results indicate that the two-stage stochastic optimization model can generate refined closure schemes and dynamically adaptive protection schemes for risky metro stations. Compared to one-stage strategies that do not consider the uncertainty of rainstorms, the two-stage model achieves higher passenger utility. Furthermore, the mechanisms behind the closure decisions made by the two-stage model are interpreted using an explainable artificial intelligence (XAI) technique, SHAP (SHapley Additive explanation). It is revealed that a metro station with low passenger volume in a high-rainfall sub-catchment has a greater probability of being closed before floods. Future works can be conducted to further explore feedback mechanisms between the two optimization stages or optimize the location and inventory of resource warehouses for metro systems.
The adipose tissue is a metabolically active endocrine organ with a dynamic secretome that is known to be implicated in metabolic disorders. Various studies have demonstrated detrimental downstream endocrinal effects ...
详细信息
The adipose tissue is a metabolically active endocrine organ with a dynamic secretome that is known to be implicated in metabolic disorders. Various studies have demonstrated detrimental downstream endocrinal effects of dysfunctional adipose tissue on other metabolic tissues, such as skeletal muscle and liver. In vitro ‘Adipose-on-Chip’ (AOC) models have been developed as an animal-alternative experimental platform to mimic adipose dysfunction in metabolic diseases. However, existing AOCs have not modeled both overtime lipid accumulation and inflammation of adipocytes in the presence of excess circulating free fatty acids (FFA), which are hallmarks of dysfunctional adipose tissue in obesity. This study reports for the first time, the establishment of a physiologically-relevant AOC disease model, which mimics adipose tissue pathophysiology in obesity via excessive FFA loading. The AOC model supports 3D perfusion culture of human bone marrow mesenchymal stem cell (BMMSC) differentiated adipocytes with improved adipogenic phenotypes as compared to conventional 2D well-plate cultures. Adipocytes in the AOC can be induced into a diseased phenotype on-chip, where they become both hypertrophic and inflamed when treated with an FFA mixture. This AOC disease model provides a more physiological experimental system to study the effects of adipose tissue dysfunction on downstream tissues for mechanistic investigations into obesity-related metabolic diseases.
This study combines reactive and antisolvent crystallization concepts via mixing-induced supersaturation to demonstrate a wider range of options for solvent system selection in multicomponent crystallization. This app...
详细信息
暂无评论