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Persistent heavy rainfall events (PHREs), as a result of the interaction among multiscale systems, are prone to continuously affect the middle and lower reaches of the Yangtze River valley (MLYR). Based on the observation and reanalysis data, a total of 41 PHREs during the mei-yu seasons of 1979–2020 are first identified over the MLYR and divided into prolonged (over 5 days) and normal (3–5 days) groups. The contributions of quasi-biweekly-scale and synoptic-scale components to the abovementioned two types of PHREs are analyzed. Prolonged PHREs are dominated by the quasi-biweekly component of precipitation (QBW_Pr), while normal PHREs depend on synoptic-scale components (SS_Pr). The quantitative moisture budget indicates that the favorable environment for the QBW_Pr of prolonged PHREs is associated with the interaction between background moisture and quasi-biweekly circulation disturbances. Approximately 80% of prolonged PHREs occurred in phases 6–8 of the boreal summer QBWO (BSISO2) life cycle. The large-scale meridional vertical circulation along the South China Sea (SCS)–MLYR, and the westward-propagating suppressed convection at low latitudes, accompanied by the substantial northward and upward moisture supply, significantly promotes and maintains the QBW_Pr for prolonged PHREs. In contrast, the QBWO signals are relatively insignificant in the evolution of normal PHREs. The impact of the low-latitude QBWO on the prolonged PHREs is further confirmed by sensitivity experiments with RegCM4.9. As the QBWO are weakened on the southeast lateral boundary near the SCS, the vertical circulation and moisture transport clearly diminish along the SCS–MLYR. Consequentially, precipitation reduces visibly during prolonged PHREs. Significance Statement Persistent heavy rainfall events (PHREs), as the reflection of the interaction among multiscale circulation systems, characterized by high intensity and wide coverage, are prone to cause severe flooding and death in the middle and lower reaches of the Yangtze River valley (MLYR). This study aims to investigate the connection between PHREs and different time scales of atmospheric variability, thus elucidating the crucial factors and the influencing mechanisms for the prolonged PHREs during the mei-yu season. Our results reveal that the prolonged PHREs are dominated by the quasi-biweekly component of precipitation, while normal PHREs depend on the synoptic-scale component. The quasi-biweekly precipitation of prolonged PHREs is promoted and maintained by the meridional vertical circulation along the South China Sea (SCS)–MLYR, which is accompanied by the westward-propagating SCS QBWO-related suppressed convection at low latitudes. This study highlights the specific role of the low-latitude QBWO to the formation of prolonged PHREs relative to normal PHREs.

The complexity and heterogeneity of urban land surfaces result in inconsistencies in near-surface winds, which in turn influence the diffusion and dispersion of air pollutants. In this study, we classified urban surface wind fields, quantified their steadiness, duration, and influence on air quality using hourly wind observations from 50 meteorological stations, as well as hourly PM

In view of the shortcomings of water supply network optimization design based on the traditional genetic algorithm in water supply safety and economy, an improved crossover operator adaptive algorithm and penalty function are proposed to improve the traditional genetic algorithm, which can effectively solve the problem of local optimal solution caused by too early convergence of the traditional genetic algorithm in pipe network optimization design. Taking a typical annular water supply network as an example, the calculation results show that the economy of the design scheme of the improved genetic algorithm is better than the traditional genetic algorithm, which fully shows that the improved genetic algorithm is practical and effective for the optimal design of water supply network.

Based on observation data supplied by the Chinese Meteorological Administration (CMA) and reanalysis datasets provided by the ECMWF, the multiscale causes of persistent heavy rainfall events (PHREs) that occurred from 1979 to 2018 during Meiyu periods over the middle and lower reaches of the Yangtze River (MLYR) are investigated. During Meiyu periods, precipitation shows obvious interannual variabilities. In PHRE years, the contribution rate of persistent heavy rainfall to the total precipitation is approximately 57%. Precipitation also shows significant synoptic-scale (less than 10 days) characteristics. Through the quantitative diagnosis of interactions among background-scale (greater than 30 days), quasi-biweekly-scale (10–30-days), and synoptic-scale variables, the possible causes of PHREs are explored. The results reveal that the difference in precipitation intensity between PHRE years and non-PHRE years is determined by the background water vapor, background wind and synoptic-scale wind conditions. In PHRE years, the prevailing background southwesterly winds from lower latitudes provide more background water vapor, and more mean kinetic energy is converted to perturbation energy. Moreover, the active synoptic-scale oscillations from higher latitudes and the convergence of Rossby wave disturbance energy over the MLYR could also cause the occurrence and maintenance of PHREs during Meiyu periods. The multiscale causes and corresponding circulation patterns in 2020 PHREs are similar to PHREs years.

Erythropoietin (EPO) is not only an erythropoiesis hormone but also an immune-regulatory cytokine. The receptors of EPO (EPOR)2 and tissue-protective receptor (TPR), mediate EPO’s immune regulation. Our group firstly reported a non-erythropoietic peptide derivant of EPO, cyclic helix B peptide (CHBP), which could inhibit macrophages inflammation and dendritic cells (DCs) maturation. As a kind of innate immune regulatory cell, myeloid-derived suppressor cells (MDSCs) share a common myeloid progenitor with macrophages and DCs. In this study, we investigated the effects on MDSCs differentiation and immunosuppressive function via CHBP induction. CHBP promoted MDSCs differentiate toward M-MDSCs with enhanced immunosuppressive capability. Infusion of CHBP-induced M-MDSCs significantly prolonged murine skin allograft survival compared to its counterpart without CHBP stimulation. In addition, we found CHBP increased the proportion of CD11b+Ly6G−Ly6Chigh CD127+ M-MDSCs, which exerted a stronger immunosuppressive function compared to CD11b+Ly6G−Ly6Chigh CD127− M-MDSCs. In CHBP induced M-MDSCs, we found that EPOR downstream signal proteins Jak2 and STAT3 were upregulated, which had a strong relationship with MDSC function. In addition, CHBP upregulated GATA-binding protein 3 (GATA-3) protein translation level, which was an upstream signal of CD127 and regulator of STAT3. These effects of CHBP could be reversed if Epor was deficient. Our novel findings identified a new subset of M-MDSCs with better immunosuppressive capability, which was induced by the EPOR-mediated Jak2/GATA3/STAT3 pathway. These results are beneficial for CHBP clinical translation and MDSC cell therapy in the future.

In this paper, a rainfall runoff pollution prediction method based on grey neural network algorithm is proposed in consideration of the current situation that the accuracy of research results related to rainfall runoff pollution prediction needs to be improved. Meanwhile, the characteristics of rainfall runoff pollution are analyzed from the perspectives of the main sources of rainfall runoff pollution, the types of rainfall runoff pollution, and the initial erosion. The neural network algorithm is optimized and trained according to the sample data to obtain the sample features; the sample data are predicted according to the extracted sample features, and the prediction model is generated by using the feature fusion technology for two groups of prediction results to generate the prediction model and realize the water drop prediction. The pollution concentration of runoff was obtained by the exponential function method. The experimental results show that the predicted values of discharge and pollution concentration are well fitted with the actual values, indicating that the proposed method has high accuracy and feasibility. Finally, from the viewpoint of non-engineering measures and engineering measures, the suggestions for treating runoff pollution and relevant supports for ecological environment protection are given.

Viral myocarditis, mainly caused by enteroviruses specially coxsackievirus B3 (CVB3) infection, is a common clinical cardiovascular disease and characterized by cardiac massive inflammation. Our previous study showed that CVB3-induced myocardial NLRP3 contributed to the development of viral myocarditis. In this study, we found that beside of being up-regulated in myocardiocytes, NLPR3 was also obviously increased in the cardiac infiltrating macrophages. While whether this accumulated NLRP3 influences, macrophage inflammatory responses remains unknown. By adoptive transfer assays, we found that mice receiving NLRP3 up-regulated macrophages showed much more abundant cardiac IL-1β production and more severe myocardial inflammation, while those receiving NLRP3 down-regulated macrophages showed much less IL-1β production and milder myocarditis, indicating that NLRP3 up-regulated macrophages played a pathological role in CVB3-induced myocarditis. In addition, we further found that it was CVB3 capsid proteins VP1 (predominant) and VP2, but not viral RNAs, robustly triggered macrophage NLRP3 up-regulation and activation. Our study demonstrated macrophage NLRP3 inflammasome could be efficiently be activated by CVB3 capsid proteins, and contributed to the pathogenesis of viral myocarditis. It might provide some clues to the development of new therapeutic strategies based on macrophage NLRP3 modulation.

High mobility group box 1 (HMGB1) presents in almost all somatic cells as a component of the cell nucleus. It is necessary for transcription regulation during cell development. Recent studies indicate that extracellular HMGB1, coming from necrotic cells or activated immune cells, triggers inflammatory response whereas intracellular HMGB1 controls the balance between autophagy and apoptosis. In addition, reduced HMGB1 can effectively mediate tissue regeneration. HMGB1, therefore, is regarded as a therapeutic target for inflammatory diseases. In this review, we summarized and discussed the immunomodulatory effect of HMGB1.

Streptococcus aureus (S. aureus)-induced acute lung injury (ALI) has a high incidence of mortality clinically. Glycyrrhizin (GL) is a traditional Chinese medicine for anti-inflammatory. However, the role of GL in S. aureus-induced ALI has not previously been elucidated. GL (25 mg/kg i.p.) administration exerts potent anti-inflammatory effect in this model. GL administration significantly alleviated inflammation via reduction of multiple cytokines (serum and lung tissue IL-6, TNF-α, IL-8, IL-1β and HMGB1) and immune cells (lung tissue neutrophil and macrophage infiltration). Additionally, we measured the signaling pathways (NF-kB and MARKs) and inflammasome dependent pyroptosis. The results suggest that GL inhibits NF-kB, p38/ERK pathways and pyroptosis. Furthermore, we used different inhibitors to treat infected-A549 cells and found that BMS-582949 (a p38 inhibitor) is the most effective inhibitor for inhibiting pro-inflammatory cytokines (IL-6, TNF-α and IL-1β) production, which suggests that p38 signaling pathway might be the main pathway for S. aureus-induced inflammation. Collectively, the data demonstrates that GL could mitigate inflammation after S. aureus infection.

Infiltrating macrophages have been proven as a pivotal pathological inflammatory cell subset in coxsackievirus B3 (CVB3) induced viral myocarditis. However, the mechanisms underlying the initiation and promotion of macrophage pro-inflammatory responses are still blur. We previously reported that cardiac ER stress contributed to CVB3-induced myocarditis by augmenting inflammation. In this study, we focused on the influence of ER stress on the macrophage inflammatory responses in the viral myocarditis. We found that ER stress was robustly induced in the cardiac infiltrating macrophages from CVB3-infected mice, and robustly facilitated the production of pro-inflammatory cytokines (IL-6, IL-12, MCP-1 and IP-10). Consistently, adoptive transfer of ER stressed macrophages significantly worsened the viral myocarditis; while transfer of ER stress-inhibited macrophages obviously alleviated the myocarditis. To our surprise, this significantly activated ER stress was not directly caused by the virus stimulation, but was transferred from the CVB3-infected, ER stressed myocardiocytes via soluble molecules in a TLR2, 4-independent way. In the present study, we reported that the transmissible ER stress from the infected myocardiocytes to macrophages could augment the pro-inflammatory responses and promoted the pathogenesis of viral myocarditis. Blocking ER stress transmission, instead of inhibiting its initiation, may represent novel therapeutic strategies against viral myocarditis.