The escalation of anthropogenic heat emissions poses a significant threat to the urban thermal environment as cities continue to develop. However, the impact of urban spatial form on anthropogenic ...heat flux (AHF) in different urban functional zones (UFZ) has received limited attention. In this study, we employed the energy inventory method and remotely sensed technology to estimate AHF in Beijing’s central area and utilized the random forest algorithm for UFZ classification. Subsequently, linear fitting models were developed to analyze the relationship between AHF and urban spatial form indicators across diverse UFZ. The results show that the overall accuracy of the classification was determined to be 87.2%, with a Kappa coefficient of 0.8377, indicating a high level of agreement with the actual situation. The business/commercial zone exhibited the highest average AHF value of 33.13 W m−2 and the maximum AHF value of 338.07 W m−2 among the six land functional zones, indicating that business and commercial areas are the primary sources of anthropogenic heat emissions. The findings reveal substantial variations in the influence of urban spatial form on AHF across different UFZ. Consequently, distinct spatial form control requirements and tailored design strategies are essential for each UFZ. This research highlights the significance of considering urban spatial form in mitigating anthropogenic heat emissions and emphasizes the need for customized planning and renewal approaches in diverse UFZ.
The wetness index (W) was calculated using gridded monthly precipitation and potential evapotranspiration (PET) in the Beijing–Tianjin–Hebei region of China. Meteorological data from 1991 to 2020 ...were provided by the Climate Research Unit. The change in W and the factors influencing it were analyzed at regional and urban levels. The results show that (1) W of the Beijing–Tianjin–Hebei region fluctuated greatly year by year. W decreased (p < 0.05) during the years from 1991 to 2000, rose slightly (p < 0.05) from 2001 to 2010, and experienced almost no change in the last decade. (2) In the last two decades, W in some areas of the Beijing–Tianjin–Hebei region increased, probably owing to the increase in precipitation in this area. (3) In the context of climate warming, W values in the Beijing–Tianjin–Hebei region and major cities are affected by precipitation, while temperature has little impact on the values.
•CCE calculation was based on taxi trajectory.•G2SFCA was used to optimize the VSP model to calculate CCE.•Morning peak commuting had higher carbon emissions than evening peak commuting.•CCE was ...higher in the main urban area and western part of the central city.•CCE was higher in financial areas, urban ring roads and airport highways.
Commuting carbon emissions (CCE) constitute a significant portion of urban carbon emissions and exert a notable influence on urban land use policies and spatial planning strategies. Traditional methods for estimating CCEs have many disadvantages and are less accurate in terms of space and time. In this study, a typical weekday in the main urban area of Beijing is selected as the research object. First, taxi CCEs are estimated by an improved VSP model based on GPS trajectory data. Second, taxi CCEs are obtained by filtering the commuting trajectories based on POI data and taxi trajectories. Finally, the spatial distribution characteristics of taxi CCEs are analysed by spatial autocorrelation. The results show that (1) the morning peak commuting carbon emission in Beijing reaches 5338.04 kg/h, accounting for 26.13 % of the total carbon emission of cab trips; the evening peak commuting carbon emission reaches 3858.73 kg/h, accounting for 18.89 % of the total carbon emission of cab trips; (2) the spatial distribution of CCE in Beijing shows that the western part of the core area is higher, while the northeast and southwest of the central city are higher; (3) High-value commuting carbon emission areas are mainly concentrated in regions with a more developed financial industry; the carbon emissions from the city ring road and airport highway significantly surpass those of other areas. This research introduces an innovative approach to examine CCE and measure it within various functional zones of urban areas. The findings of this study can serve as valuable guidance for informing future urban spatial configurations and land use policies, leading to more effective and sustainable urban development.
Today, China's development mode has shifted from extensive management to meticulous management, so it is inevitable that data will be used to conduct quantitative analysis. In this study, we ...synthesized multi-source data and the term frequency-inverse document frequency (TF-IDF) algorithm to determine the dominant function of land within the Fifth Ring Road of Beijing, China. Additionally, we explored how point of interest (POI) distributions affect nighttime artificial light radiation using the Spearman correlation coefficient. The overall accuracy of land functional classification in the central urban area of Beijing was 88.07%, and the kappa coefficient was 85.28%. The core area of Beijing is dominated by commercial and business facilities, accounting for 29.37% of the total area, followed by residential (22.02%), mixed-use (16.51%), green space (10.62%), administration and public service (9.66%), transportation (9.31%), and industrial (2.52%) areas. The number of commercial and business facilities, administration and public services, and residential areas correlate positively with the vegetation adjusted nighttime light (NTL) urban index (VANUI) value. In contrast, the number of industrial facilities yielded a negative correlation with VANUI. This study provides support for the optimization of the functional layout and the distribution of public resources in the central urban area of Beijing.
Diabetes mellitus (DM), a most common chronic disease, is featured with impaired endothelial function and bioavailability of nitric oxide (NO), while E3 ubiquitin ligase appears to alleviate ...endothelial dysfunction as a promising option for DM treatment. Herein, we aimed to determine whether E3 ubiquitin ligase casitas B-lineage lymphoma (Cbl) alleviates endothelial dysfunction in DM rats by JAK2/STAT4 pathway.
A rat model of DM was developed through intraperitoneal injection of streptozotocin, followed by collection of aortic tissues to determine the expression of Cbl, JAK2, runt-related transcription factor 3 (Runx3) and STAT4. Human umbilical vein endothelial cells (HUVECs) were cultured in high glucose (HG) condition to induce DM as an in vitro model. With gain- and loss-function method, we assessed the aberrantly expressed Cb1 on endothelial dysfunction, NO production and apoptosis of HUVECs.
Cbl was reduced in DM rat tissues and HG-induced HUVECs, where JAK2, Runx3 and STAT4 were elevated. It was found that overexpression of Cbl alleviated endothelial dysfunction by increasing NO production and restoring vasodilation and suppressing apoptosis of HUVECs. Mechanistically, Cb1 enhanced JAK2 ubiquitination and decreased JAK2 and STAT4 expression, where STAT4 improved Runx3 expression by regulating histone H3 lysine 4 trimethylation level. Overexpression of JAK2 and STAT4, or Runx3 increased apoptosis of HUVECs, abrogating the effect of Cb1 on endothelial function.
In conclusion, Cbl alleviates endothelial dysfunction by inactivation of the JAK2/STAT4 pathway and inhibition of Runx3 expression in DM. These evidence might underlie novel Cbl-based treatment against DM in the future.
The protein PIAS1 functions as a type of ubiquitin-protease, which is known to play an important regulatory role in various diseases, including cardiovascular diseases and cancers. Its mechanism of ...action primarily revolves around regulating the transcription, translation, and modification of target proteins. This study investigates role and mechanism of PIAS1 in the RUNX3/TSP-1 axis and confirms its therapeutic effects on diabetes-related complications in animal models. A diabetic vascular injury was induced in human umbilical vein endothelial cells (HUVECs) by stimulation with H
2
O
2
and advanced glycation end product (AGE), and a streptozotocin (STZ)-induced mouse model of diabetes was constructed, followed by detection of endogenous PIAS1 expression and SUMOylation level of RUNX3. Effects of PIAS1 concerning RUNX3 and TSP-1 on the HUVEC apoptosis and inflammation were evaluated using the ectopic expression experiments. Down-regulated PIAS1 expression and SUMOylation level of RUNX3 were identified in the H
2
O
2
- and AGE-induced HUVEC model of diabetic vascular injury and STZ-induced mouse models of diabetes. PIAS1 promoted the SUMOylation of RUNX3 at the K148 site of RUNX3. PIAS1-mediated SUMOylation of RUNX3 reduced RUNX3 transactivation activity, weakened the binding of RUNX3 to the promoter region of TSP-1, and caused downregulation of TSP-1 expression. PIASI decreased the expression of TSP-1 by inhibiting H
2
O
2
- and AGE-induced RUNX3 de-SUMOylation, thereby arresting the inflammatory response and apoptosis of HUVECs. Besides, PIAS1 reduced vascular endothelial injury and atherosclerotic plaque formation in mouse models of diabetes by inhibiting the RUNX3/TSP-1 axis. Our study proved that PIAS1 suppressed vascular endothelial injury and atherosclerotic plaque formation in mouse models of diabetes via the RUNX3/TSP-1 axis.
With the development of the census and monitoring of national geographical conditions in China, the availability of information has sharply increased. Progress in data mining methods and social ...application tools has provided a way for solving the problems of low resource allocation and high uncertainty in decision-making regarding planning. To relieve non-capital functions and serve the healthy development of the Beijing Metropolitan Area, we propose a new model of self-adaptive cellular automaton based on ensemble learning (EL-CA). The method is based on the data collected by monitoring geographical conditions and is guided by complex geocomputing that simulates city-scale evolution in Beijing. A comparison of predicted and real data for Beijing in 2015 demonstrated that the predictions made by the EL-CA model proposed significantly outperformed those by traditional cellular automaton (CA) models based on empirical statistics. Data on the geographical conditions in Beijing in 2007 and 2015 were employed in model simulation and training to predict the scale of the city in 2023. The urban agglomeration points in Beijing tended to be dense, the overall construction land tended to be saturated, and the growth rate of land use areas slowed. Results from the model also established that the construction land in Beijing is close to saturation from a quantitative perspective, and the potential urban expansion hotspots in the future are mainly concentrated in the Tongzhou District, the Daxing District, the Fangshan District, the south side of the fourth and fifth ring roads, and the southwest side of Pinggu District. These results can provide decision-makers in urban planning with supporting data and support Beijing to relieve Beijing of functions nonessential to its role as China's capital.
In recent years, the conflict between human activities and the natural environment has led to global warming and the emergence of extreme weather events, prompting reflection on the climate ...adaptability of buildings. Historical and cultural districts often reflect the design and construction strategies of their era, which were shaped by the prevailing social environments and natural conditions, so they typically embody construction techniques tailored to address local climatic characteristics. Consequently, in this paper, we focus on 33 historic and cultural districts within Beijing's old city, along with seven proposed historic and cultural districts, to retrieve land surface temperatures (LST) using Landsat remote sensing data and radiative transfer equations. A spatiotemporal analysis was conducted to investigate the variations in LST distribution across different historic and cultural districts and to characterize the internal temperature features within the historic and cultural districts of Beijing's old city. Research indicates the following: (1) The Dashilan area boasts the highest average LST, while the Huangcheng area records the lowest. (2) Over the past six years, most historic and cultural districts have experienced a decline in LST. Notably, the most significant reductions in average LST have been observed in the areas west of Xinjiekou, Dongsi South, and from the 3rd to the 8th Street in Dongsi. (3) Within the historic and cultural districts, hot spots of LST are primarily concentrated in the residential areas with one-story traditional houses, while cold spots are predominantly found around water, cultural relics, and modern architectural structures.
Obesity can lead to excessive lipid accumulation in non-adipose tissues, such as the liver and skeletal muscles, leading to ectopic lipid deposition and damaging target organ function through ...lipotoxicity. FGF-21 is a key factor in regulating lipid metabolism, so we aim to explore whether FGF-21 is involved in improving ectopic lipid deposition. We observed the characteristics of ectopic lipid deposition in the liver and skeletal muscles of obesity-resistant mice, detected the expression of FGF-21 and perilipin, and found that obesity-resistant mice showed a decrease in ectopic lipid deposition in the liver and skeletal muscles and increased expression of FGF-21. After inhibiting the expression of FGF-21, a more severe lipid deposition in liver cells and skeletal muscle cells was found. The results indicate that inhibiting FGF-21 can exacerbate ectopic lipid deposition via regulating lipid droplet synthesis and decomposition, as well as free fatty acid translocation and oxidation. In conclusion, FGF-21 is involved in improving ectopic lipid deposition caused by obesity in the liver and skeletal muscles.
The local climate zone (LCZ) scheme has been widely utilized in regional climate modeling, urban planning, and thermal comfort investigations. However, existing LCZ classification methods face ...challenges in characterizing complex urban structures and human activities involving local climatic environments. In this study, we proposed a novel LCZ mapping method that fully uses space-borne multi-view and diurnal observations, i.e. daytime Ziyuan-3 stereo imageries (2.1 m) and Luojia-1 nighttime light (NTL) data (130 m). Firstly, we performed land cover classification using multiple machine learning methods (i.e. random forest (RF) and XGBoost algorithms) and various features (i.e. spectral, textural, multi-view features, 3D urban structure parameters (USPs), and NTL). In addition, we developed a set of new cumulative elevation indexes to improve building roughness assessments. The indexes can estimate building roughness directly from fused point clouds generated by both along- and across-track modes. Finally, based on the land cover and building roughness results, we extracted 2D and 3D USPs for different land covers and used multi-classifiers to perform LCZ mapping. The results for Beijing, China, show that our method yielded satisfactory accuracy for LCZ mapping, with an overall accuracy (OA) of 90.46%. The overall accuracy of land cover classification using 3D USPs generated from both along- and across-track modes increased by 4.66%, compared to that of using the single along-track mode. Additionally, the OA value of LCZ mapping using 2D and 3D USPs (88.18%) achieved a better result than using only 2D USPs (83.83%). The use of NTL data increased the classification accuracy of LCZs E (bare rock or paved) and F (bare soil or sand) by 6.54% and 3.94%, respectively. The refined LCZ classification achieved through this study will not only contribute to more accurate regional climate modeling but also provide valuable guidance for urban planning initiatives aimed at enhancing thermal comfort and overall livability in urban areas. Ultimately, this study paves the way for more comprehensive and effective strategies in addressing the challenges posed by urban microclimates.
PDF
