249 research outputs found

    Modelling the impact of land subsidence on urban pluvial flooding: a case study of downtown Shanghai, China.

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    This paper presents a numerical analysis of pluvial flooding to evaluate the impact of land subsidence on flood risks in urban contexts using a hydraulic model (FloodMap-HydroInundation2D). The pluvial flood event of August 2011 in Shanghai, China is used for model calibration and simulation. Evolving patterns of inundation (area and depth) are assessed over four time periods (1991, 1996, 2001 and 2011) for the downtown area, given local changes in topography and rates of land subsidence of up to 27mm/yr. The results show that land subsidence can lead to non-linear response of flood characteristics. However, the impact on flood depths is generally minor (<5cm) and limited to areas with lowest-lying topographies because of relatively uniform patterns of subsidence and micro-topographic variations at the local scale. Nonetheless, the modelling approach tested here may be applied to other cities where there are more marked rates of subsidence and/or greater heterogeneity in the depressed urban surface. In these cases, any identified hot-spots of subsidence and focusing of pluvial flooding may be targeted for adaptation interventions

    20230502 The mechanism of Nrf2 regulating oxidative stress in diabetes nephropathy http://zglcyj.ijournals.cn/zglcyj/ch/reader/create_pdf.aspx?file_no=20230502 10.13429/j.cnki.cjcr.2023.05.002 YIN Dapeng, GUO Zhixin Department of Endocrinology, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China Oxidative stress participates in the occurrence of diabetic nephropathy(DN). Abnormal glucose metabolism will lead to the production of oxygen free radicals, damaging the intrinsic cells of the kidney, affecting the structure and function of renal tissue. Meanwhile, 〖JP2〗the high glucose-induced oxidative stress inhibits the expression of the antioxidant factor Nrf2, which activation has a protective effect on the kidney of diabetic mice, and can improve the kidney injury at the cellular level. However, the antioxidant mechanism of Nrf2 involved in DN remains unclear. This paper will introduce the role of Nrf2 in regulating oxidative stress at the cellular level to improve renal injury caused by high glucose. Oxidative stress, Nrf2, Diabetic nephropathy, Podocyte, Mesangial cells, Glomerular endothelial cells, Renal tubules, Ferroptosis 646 650 2022-12-08 2023-05-20 20230502 The mechanism of Nrf2 regulating oxidative stress in diabetes nephropathy http://zglcyj.ijournals.cn/zglcyj/ch/reader/create_pdf.aspx?file_no=20230502 10.13429/j.cnki.cjcr.2023.05.002 YIN Dapeng, GUO Zhixin Department of Endocrinology, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China Oxidative stress participates in the occurrence of diabetic nephropathy(DN). Abnormal glucose metabolism will lead to the production of oxygen free radicals, damaging the intrinsic cells of the kidney, affecting the structure and function of renal tissue. Meanwhile, 〖JP2〗the high glucose-induced oxidative stress inhibits the expression of the antioxidant factor Nrf2, which activation has a protective effect on the kidney of diabetic mice, and can improve the kidney injury at the cellular level. However, the antioxidant mechanism of Nrf2 involved in DN remains unclear. This paper will introduce the role of Nrf2 in regulating oxidative stress at the cellular level to improve renal injury caused by high glucose. Oxidative stress, Nrf2, Diabetic nephropathy, Podocyte, Mesangial cells, Glomerular endothelial cells, Renal tubules, Ferroptosis 646 650 2022-12-08 2023-05-20 The mechanism of Nrf2 regulating oxidative stress in diabetes nephropathy

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    Oxidative stress participates in the occurrence of diabetic nephropathy(DN). Abnormal glucose metabolism will lead to the production of oxygen free radicals, damaging the intrinsic cells of the kidney, affecting the structure and function of renal tissue. Meanwhile, the high glucose-induced oxidative stress inhibits the expression of the antioxidant factor Nrf2, which activation has a protective effect on the kidney of diabetic mice, and can improve the kidney injury at the cellular level. However, the antioxidant mechanism of Nrf2 involved in DN remains unclear. This paper will introduce the role of Nrf2 in regulating oxidative stress at the cellular level to improve renal injury caused by high glucose

    Validating city-scale surface water flood modelling using crowd-sourced data

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    Surface water and surface water related flood modelling at the city-scale is challenging due to a range of factors including the availability of subsurface data and difficulty in deriving runoff inputs and surcharge for individual storm sewer inlets. Most of the research undertaken so far has been focusing on local-scale predictions of sewer surcharge induced surface flooding, using a 1D/1D or 1D/2D coupled storm sewer and surface flow model. In this study, we describe the application of an urban hydro-inundation model (FloodMap-HydroInundation2D) to simulate surface water related flooding arising from extreme precipitation at the city-scale. This approach was applied to model an extreme storm event that occurred on 12 August 2011 in the city of Shanghai, China, and the model predictions were compared with a ‘crowd-sourced’ dataset of flood incidents. The results suggest that the model is able to capture the broad patterns of inundated areas at the city-scale. Temporal evaluation also demonstrates a good level of agreement between the reported and predicted flood timing. Due to the mild terrain of the city, the worst-hit areas are predicted to be topographic lows. The spatio-temporal accuracy of the precipitation and micro-topography are the two critical factors that affect the prediction accuracies. Future studies could be directed towards making more accurate and robust predictions of water depth and velocity using higher quality topographic, precipitation and drainage capacity information

    Coupled modeling of storm surge and coastal inundation: a case study in New York City during Hurricane Sandy

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    In this paper we describe a new method of modeling coastal inundation arising from storm surge by coupling a widely used storm surge model (ADCIRC) and an urban flood inundation model (FloodMap). This is the first time the coupling of such models is implemented and tested using real events. The method offers a flexible and efficient procedure for applying detailed ADCIRC storm surge modeling results along the coastal boundary (with typical resolution of ∼100 m) to FloodMap for fine resolution inundation modeling ( 70 m). In further testing, we explored the effects of mesh resolution and roughness specification. Results agree with previous studies that fine resolution is essential for capturing intricate flow paths and connectivity in urban topography. While the specification of roughness is more challenging for urban environments, it may be empirically optimized. The successful coupling of ADCIRC and FloodMap models for fine-resolution coastal inundation modeling unlocks the potential for undertaking large numbers of probabilistically-based synthetic surge events for street-level risk analysis

    Evaluating the impact and risk of pluvial flash flood on intra-urban road net- work: A case study in the city center of Shanghai, China

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    Urban pluvial flood are attracting growing public concern due to rising intense precipitation and increasing consequences. Accurate risk assessment is critical to an efficient urban pluvial flood management, particularly in transportation sector. This paper describes an integrated methodology, which initially makes use of high resolution 2D inundation modeling and flood depth-dependent measure to evaluate the potential impact and risk of pluvial flash flood on road network in the city center of Shanghai, China. Intensity–Duration–Frequency relationships of Shanghai rainstorm and Chicago Design Storm are combined to generate ensemble rainfall scenarios. A hydrodynamic model (FloodMap-HydroInundation2D) is used to simulate overland flow and flood inundation for each scenario. Furthermore, road impact and risk assessment are respectively conducted by a new proposed algorithm and proxy. Results suggest that the flood response is a function of spatio-temporal distribution of precipitation and local characteristics (i.e. drainage and topography), and pluvial flash flood is found to lead to proportionate but nonlinear impact on intra-urban road inundation risk. The approach tested here would provide more detailed flood information for smart management of urban street network and may be applied to other big cities where road flood risk is evolving in the context of climate change and urbanization

    Evaluating the cascading impacts of sea level rise and coastal flooding on emergency response spatial accessibility in Lower Manhattan, New York City

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    This paper describes a scenario-based approach for evaluating the cascading impacts of sea level rise (SLR) and coastal flooding on emergency responses. The analysis is applied to Lower Manhattan, New York City, considering FEMA’s 100- and 500-year flood scenarios and New York City Panel on Climate Change (NPCC2)’s high-end SLR projections for the 2050s and 2080s, using the current situation as the baseline scenario. Service areas for different response timeframes (3-, 5- and 8-minute) and various traffic conditions are simulated for three major emergency responders (i.e. New York Police Department (NYPD), Fire Department, New York (FDNY) and Emergency Medical Service (EMS)) under normal and flood scenarios. The modelling suggests that coastal flooding together with SLR could result in proportionate but non-linear impacts on emergency services at the city scale, and the performance of operational responses is largely determined by the positioning of emergency facilities and the functioning of traffic networks. Overall, emergency service accessibility to the city is primarily determined by traffic flow speed. However, the situation is expected to be further aggravated during coastal flooding, with is set to increase in frequency and magnitude due to SLR

    Structural Topology Optimization of Brake Disc Using the Equivalent Moving Load Method

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    During the braking process, the brake disc is subjected to the moving load. The process-point of the moving load moves along a certain trajectory, which makes it difficult to design the brake disc structure by using a traditional topology optimization method. The novel Equivalent Moving Load (EML) method proposed in this paper aims to solve this problem. According to the principle of continuous photographing technology, a mathematical model was established by using the round inward polygonal approximation algorithm. The EML method equalizes the continuous dynamic load action to many finite working conditions by geometric approximation. These working conditions are placed along the trajectory. The structure of the brake disc is then optimized by the EML method. Additionally, the influence of the layout style of the brake pads and the total number of working conditions on the optimization result are discussed in this paper. The optimization results showed that the new structure is a three-annulus structure. The weight of the new structure is reduced by 57.95% compared to the initial structure by structural topology optimization using the EML method. It was proved that structural topology optimization using the EML method is efficient in optimizing a structure subjected to dynamic load

    The chromosome-level rambutan genome reveals a significant role of segmental duplication in the expansion of resistance genes

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    Rambutan (Nephelium lappaceum var. lappaceum), a tropical fruit tree native to southeastern Asia, belongs to the family Sapindaceae. Rambutan is a popular table fruit and is also processed into preserves, juices, wines, and sorbets [1]. At present, only three Sapindaceae genomes are publicly available: Xanthoceras sorbifolium [2], Dimocarpus longan (longan) [3], and Acer yangbiense [4]. During the process of submitting this manuscript, the genome paper for the rambutan cultivar Baoyan7 became available online, but its genome sequence has not yet been released [5]

    Linking a storm water management model to a novel two-dimensional model for urban pluvial flood modeling

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    This article describes a new method of urban pluvial flood modeling by coupling the 1D storm water management model (SWMM) and the 2D flood inundation model (ECNU Flood-Urban). The SWMM modeling results (the overflow of the manholes) are used as the input boundary condition of the ECNU Flood-Urban model to simulate the rainfall–runoff processes in an urban environment. The analysis is applied to the central business district of East Nanjing Road in downtown Shanghai, considering 5-, 10-, 20-, 50-, and 100-year return period rainfall scenarios. The results show that node overflow, water depth, and inundation area increase proportionately with the growing return periods. Water depths are mostly predicted to be shallow and surface flows generally occur in the urban road network due to its low-lying nature. The simulation result of the coupled model proves to be reliable and suggests that urban surface water flooding could be accurately simulated by using this methodology. Adaptation measures (upgrading of the urban drainage system) can then be targeted at specific locations with significant overflow and flooding
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