IL-6 significantly correlated with the prognosis in low-grade glioma and the mediating effect of immune microenvironment.

To screen immune-related prognostic biomarkers in low-grade glioma (LGG), and reveal the potential regulatory mechanism. The differential expressed genes (DEGs) between alive and dead patients were initially identified, then the key common genes between DEGs and immune-related genes were obtained. Regarding the key DEGs associated with the overall survival (OS), their clinical value was assessed by Kaplan-Meier, RCS, logistic regression, ROC, and decision curve analysis methods. We also assessed the role of immune infiltration on the association between key DEGs and OS. All the analyses were based on the TGCA-LGG data. Finally, we conducted the molecular docking analysis to explore the targeting binding of key DEGs with the therapeutic agents in LGG. Among 146 DEGs, only interleukin-6 (IL-6) was finally screened as an immune-related biomarker. High expression of IL-6 significantly correlated with poor OS time (all P < .05), showing a linear relationship. The combination of IL-6 with IDH1 mutation had the most favorable prediction performance on survival status and they achieved a good clinical net benefit. Next, we found a significant relationship between IL-6 and immune microenvironment score, and the immune microenvironment played a mediating effect on the association of IL-6 with survival (all P < .05). Detailly, IL-6 was positively related to M1 macrophage infiltration abundance and its biomarkers (all P < .05). Finally, we obtained 4 therapeutic agents in LGG targeting IL-6, and their targeting binding relationships were all verified. IL6, as an immune-related biomarker, was associated with the prognosis in LGG, and it can be a therapeutic target in LGG.

Coupling stable isotopes to evaluate sources and transformations of nitrate in groundwater and inflowing rivers around the Caohai karst wetland, Southwest China.

Nitrate is one of the most common pollutants in aquatic ecosystems, particularly in highly vulnerable karst aquifers. In Caohai Lake, an important karst wetland in southwestern China, karst surface water and groundwater are important recharge water sources, and nitrates flow into the wetland along with the surface water and groundwater, degrading the wetland water quality. Therefore, identifying the sources of nitrate in the surface water and groundwater in the Caohai catchment is of great significance to the protection of the wetland water environment. In this study, the nitrate concentrations, hydrochemistry and multiple stable isotope ratios (δ18O-H2O, δD-H2O, δ15N-NO3- and δ18O-NO3-) were used to identify the sources and fate of the NO3- in the groundwater and inflowing rivers around the Caohai wetland. The results showed that the NO3- concentrations in the groundwater samples from the southern side exceeded the WHO limit during the wet season, while other samples did not exceed the limit. The mean concentrations of NO3- in groundwater were higher than those in the inflowing river water, and NO3- concentrations decreased in the order of wet season>dry season>normal season in the groundwater and inflowing rivers. The hydrochemistry and multiple isotope ratios suggest that the nitrate transformation was dominated by nitrification processes, while denitrification had an influence on the transformation of NO3- (as evidenced by isotopes) in groundwater during the dry season. According to the analyses based on a stable isotope analysis in R (SIAR), sewage and manure were the main sources of NO3- in the groundwater, while sewage, manure and chemical fertilizer were the major sources of NO3- in the inflowing river water; therefore, the scientific use of farmland fertilizers and the treatment of domestic sewage should be strengthened to safeguard groundwater quality and control the NO3- concentrations in rivers.

[Hydrochemistry Characteristics and Estimation of the Dissolved Inorganic Carbon Flux in the Caohai Lake Wetland Catchment of Guizhou Province].

The Caohai Lake wetland in Weining County, Guizhou Province, is the largest karst wetland in China, and karst groundwater is an essential source of recharge and material. This study collected groundwater from the Caohai Lake catchment during the wet season, dry season, and flat season, and the main ion components of the groundwater were analyzed. The hydrochemistry characteristics and main ion sources of the groundwater were revealed, and the preliminary estimates of the karst carbon sink flux in the Caohai Lake catchment were calculated based on the solute load method. The results indicated that the water chemistry of the groundwater in the Caohai Lake catchment is primarily the HCO3-Ca type, and individual groundwater points in the southeast are the SO4-Ca type during the flat season. The dominant ions in the groundwater are Ca2+, Mg2+, and HCO3-. Seasonally, the average concentrations of SO42- and Mg2+ decreased in the order of flat season>dry season>wet season, while the average concentration of NO3- decreased in the order of wet season>dry season>flat season, and the seasonal variation of the other ions were not significant. Spatially, the concentrations of Ca2+ and HCO3- in the groundwater in the northern part of Caohai Lake, of K+, Na+, and Cl- in the southwest, and of Mg2+, NO3-, and SO42- in the southeast were relatively high. Ca2+, Mg2+, and HCO3- in the groundwater were primarily controlled by the dissolution of carbonate rocks, and carbonic acid, sulfuric acid and nitric acid were all involved in the weathering of carbonate rocks in the catchment. Most of the NO3- in the groundwater was affected mostly by the soil nitrogen and domestic sewage, while NO3- in the southeast groundwater was primarily affected by agricultural activities. The sources of K+, Na+, Cl-, and SO42- exhibited no obvious temporal and spatial differences, and the K+, Na+, and Cl- were mainly affected by human activities, while SO42- was mostly derived from the dissolution of sulfur compounds in the formation. The studied area has a high proportion of allogenic acids (sulfuric acid and nitric acid) participating in the weathering of carbonate rocks, which is the highest in the flat season and the lowest in wet season. After deducting the proportion of allogenic acids participating in the weathering of carbonate rocks, the average inorganic carbon flux in the Caohai Lake catchment is preliminarily estimated to be approximately 181.5 t·a-1, and the average karst groundwater transport of HCO3- to Caohai Lake is approximately 1144.1 t·a-1.