Fibroblast growth factor 21 (FGF21) is an endocrine hormone that exerts bene cial effects on glucose and lipid metabolic homeostasis. However, the impact of FGF21 on type 1 diabetes-associated cognitive decline (DACD) and its mechanisms of action remain unclear. In this study, we aimed to evaluate the effects of FGF21 on lactate uptake and usage in a mouse model of streptozotocin-induced DACD. Sixweek-old male C57BL/6 mice were divided into the control, diabetic, and FGF21 (which received 2 mg/kg recombinant human FGF21) groups. At the end of the treatment period, learning and memory performance, nuclear magnetic resonance-based metabonomics, and expressions of various hippocampal protein were analyzed to determine the e cacy of FGF21. The results showed that, compared to the control mice, the diabetic mice had reduced long-term memory performance after the hyperglycemic insult; decreased hippocampal levels of lactate dehydrogenase-B (LDH-B) activity, bioenergy metabolites, and monocarboxylate transporter 2 (MCT2); as well as increased lactate levels.Impaired phosphoinositide 3-kinase (PI3K) signaling was also observed in the diabetic mice. However, FGF21 treatment restored LDH-B activity, β-nicotinamide adenine dinucleotide, and ATP levels; increased MCT2 expression and PI3K signaling pathway, which in turn improved the learning and memory defects. These ndings demonstrated that the effects of FGF21 in DACD were associated with its ability to improve LDH-B-mediated lactate usage and MCT2-dependent lactate uptake. Further, these bene cial effects of FGF21 in the hippocampus were mediated by the PI3K signaling pathways.

Regenerating cities must blend modernization and heritage. Both urban morphology and Historic Urban Landscape (HUL) highlight historical processes and may assist in regeneration. Using Chongqing as the study example may further understand mountain cities, which are prevalent worldwide but seldom examined in morphology research. This study explores and organizes the historical modernization of Chongqing’s parent city from early-modern times to the present day using a universal approach established in this research developed by the HUL perspective and research framework, Geographic information system (GIS), Depthmap tool, and historical map translation method. Large-scale modernization occurred prior to the 1980s, followed by more modest rehabilitation projects. The whole procedure is described by the phrase “Construction first, then planning, then transformation,” which entails a “free growth” block structure at the outset, along with planning control. The study contributes the following: (1) Establishing a theoretical framework and research technique for the universal city based on historical sources and modern instruments; (2) Chongqing’s future sustainable development and historical preservation depend in large part on figuring out the city’s complicated modernization history; (3) The study of mountain cities may benefit from understanding the geographical development and spatial dynamic layering of Chongqing. (4) This study bridges the gap in time by going beyond the early modern period covered by the previous ones and into the post-statehood era (1949–2022).

China has undergone a tremendous urbanization process over the past four decades, resulting in a considerable conflict between the desire to construct contemporary urban areas and the desire to safeguard old urban structures. In addition to destroying the physical space of ancient urban sites, urban development has fragmented the natural landscape and severed its structural relationship with the historical urban landscape. In this study, we selected Luoyang as the research object and digitally translated and laminated the laminar process of Luoyang’s historical urban landscape based on historical maps and related historical documents. It is intended to establish a digital historical urban landscape information database comprising data from different periods of the city through the systematic translation of historic maps and through combining the following different landscape carriers: urban spatial patterns, roads and streets, landscape units, and landmark buildings. While reading the historical maps of the city, the spatial analysis tool, ArcGIS, was used to identify the trajectory of the spatial evolution of Luoyang’s spatial structure throughout its history. In this paper, we suggest the establishment of a Luoyang urban historical axis system to integrate the city’s fragmented historical urban landscape, thereby strengthening the social perception of such historical urban landscapes and preserving their memory.

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With the rapid increase of network data, there are many challenges of security about data sharing in big data environment. The traditional attribute-based access control model generally adopts the centralized method. In the process of practical operation, once the decision node is attacked, the method will bring security risks to data resources. In order to improve the security of centralized access control and adapt to both dynamic and fine-grained characteristics of data access control in big data environment. The decentralized access control method for big data is proposed by combining the blockchain technology with attribute-based access control model.