The activation of IL-17 signaling has been linked to the pathogenesis of many chronic, inflammatory lung diseases including cystic fibrosis. Through unbiased single-cell RNAseq screening, we found that IL-17+ T cells highly express Srm and Smox, which encode two key enzymes involved in spermidine synthesis, spermidine synthase and spermine oxidase respectively. Spermidine has been shown to reduce inflammation by regulating macrophage activation and balancing Th17/Treg differentiation; however its direct effects on Th17 cytokine production have not been carefully investigated. Here, using already differentiated Th17 cells from cultured mouse splenocytes, we found that exogenous spermidine directly inhibits IL-1β/IL-23-induced IL-17 production. Blockade of endogenous spermidine synthesis enhanced IL-17 production above native levels, further supporting the notion that spermidine is a direct regulator of cytokine secretion independent of differentiation. In vivo, spermidine alleviates lung inflammation in both Pseudomonas aeruginosa (PA) and LPS induced acute lung injury models. Further RNA-seq analysis suggests that spermidine suppression of Th17 cytokine production is mediated through its PRDX1-dependent antioxidant activity. Our data suggests that spermidine is a direct regulator of Type-17 T cell cytokine production and has potent anti-inflammatory effects against lung inflammation.
This study compares the accuracy of two genomic approaches in estimating genetic diversity levels, which could be useful for informing species conservation assessments of abundant, exploited fish species. The first approach (SNP-calling-based) is the commonly used pipeline of SNP calling followed by SNP filtering at a determined Minor Allele Frequency (MAF). The second approach (genotype-likelihood-based) does not perform SNP calling but estimates the Site Spectrum Frequency (SFS) based on alignment quality and sample size. The results show up to two-fold differences in the magnitude of the estimated nucleotide diversities among the analyzed datasets. The SNP-calling-based approach produces overestimates when missing data are considered in the analysis and shows pronounced deviations of the SFS towards high-frequency SNPs when filtering by MAF > 5%. The genotype likelihood-based approach showed that nucleotide diversity estimates significantly deviated from neutral expectations, as expected based on the known history of the case-study fish population analyzed here, regardless of whether missing data were considered. In contrast, the SNP-calling-based approach only shows this expected difference when no missing data are included and no MAF filtering is performed. Overall, the results indicate that using the SNP-calling-based approach may hide the effects of population size declines in abundant exploited fish species, while genotype-likelihood-based estimates of nucleotide diversity can effectively contribute to informing conservation assessments.
In recent years, researchers have focused on exploring alternative fuel technologies that enhance engine performance and combustion efficiency while reducing nitrogen oxide (NOx) and particulate matter (PM) emissions. Water-diesel emulsified fuel, which requires no engine modifications, has emerged as a critical pathway for cleaner diesel engine applications. This review systematically examines the combustion characteristics, emission performance, and energy efficiency of emulsified fuels in compression ignition (CI) engines. Studies indicate that compared to conventional pure diesel, emulsified fuels significantly optimize combustion processes through micro-explosion phenomena, shorten ignition delays, and improve combustion efficiency. Notably, NOx and PM emissions are simultaneously reduced, effectively resolving the traditional trade-off dilemma between pollutant reduction targets. Emulsified fuel exhibits comparable power output and fuel consumption rates to those of pure diesel, while delivering enhanced environmental benefits. Additionally, innovative technologies such as hydrogen nanobubbles further enhance combustion dynamics by improving fuel atomization and radical generation, though challenges persist in stabilizing non-aqueous nanobubbles and scaling up production. Despite ongoing advancements in policy incentives (e.g., green hydrogen subsidies) and combustion mechanism research, industrial adoption of emulsified fuels still faces technical hurdles, including equipment corrosion and issues with long-term storage stability issues. In conclusion, water-based emulsified fuels and hydrogen-water blending technologies provide efficient and low-cost transitional solutions for reducing diesel engine emissions, with their multi-component synergistic optimization mechanisms laying a theoretical and practical foundation for future clean fuel development.
Ecological conservation and governance play key roles in constructing an ecological civilization society, while intergovernmental cooperation provides new perspectives for cross-regional ecological governance. We employed a social network analysis (SNA) method to examine 110 published ecological policies from 2000 to 2024 in the Source Region of the Yangtze River (SRYR). The study has three key findings. Firstly, intergovernmental collaborative policies on ecological protection showed an upward trend, with intra-provincial collaborations within Qinghai Province being the most frequent. Secondly, four collaboration models were demonstrated, namely: national ministries, national and provincial, cross-provincial and intra–provincial collaborations. National agencies and Qinghai provincial agencies collaboratively set objectives, which Qinghai operationalizes with incentive-constraint measures. Then, the targeted guidelines were launched by national and provincial authorities. Afterward, cross–provincial agreements and mechanisms facilitate joint actions. Thirdly, we revealed the hierarchical structures, including a national network, two central-local sub-networks, three-tier inter-provincial partnerships, and four regional sub-clusters. Core actors include national ministries that coordinate cross-departmental efforts. The Qinghai provincial government serves as a central-local hub. It maintains strong transboundary ties with Aba and Ganzi Prefectures of Sichuan Province. Provincial departments such as ecology and environment, forestry and grasslands, and finance lead intra-provincial collaborations. These findings offer new insights for integrating multi-level governance in ecological protection and ecological civilization construction.
