[Hydro-chemical Characteristics and Ion Origin Analysis of Surface Groundwater at the Shengjin Lake and Yangtze River Interface].

The interface between Shengjin Lake and Yangtze River was selected as the study area. The water chemical composition and hydrogen and oxygen isotope values of different types of water bodies were tested, and their seasonal variation characteristics were analyzed to explore the sources of chemical ions in the surface and groundwater. Finally, the contribution of mixed water sources to chemical ions in groundwater was estimated. The results show the following ① The concentration of chemical ions in the surface and groundwater of the study area is higher than that of atmospheric precipitation, and the physical and chemical parameters exhibit seasonal variation. ② Surface water mainly belongs to the Ca-HCO3 type, but the proportion of the Ca-SO4 type in summer is significantly lower than that in other seasons; Groundwater primarily belongs to Ca-HCO3 and Ca-SO4 types, with proportions of 46% and 27%, respectively, and the seasonal difference is not significant. ③ Ca2+ and Mg2+ in the surface and groundwater mainly come from the dissolution of carbonate rocks, carbonic acid and sulfate ions participate in the dissolving process of carbonate minerals. Na+and Cl- are partly derived from atmospheric precipitation and partly sourced from agricultural fertilization and manure sewage. ④ Mixed water sources is also an important source of chemical ions in groundwater, with the average contribution 28% to Cl-, showing a seasonal trend.

[Remote Sensing Monitoring on Spatial Differentiation of Suspended Sediment Concentration in a River-Lake System Based on Sentinel-2 MSI Imaging:A Case for Shengjin Lake and Connected Yangtze River Section in Anhui Province].

Carrying out monitoring of suspended sediment concentration in river and lake systems is of great significance for understanding the laws of sediment transport in water and formulating policies on water environmental control. Taking Shengjin Lake and the connected Yangtze river section in Anhui province as the study area, band reflectance of a Sentinel-2 MSI sensor is simulated according to field spectral datasets, and the retrieval model is established by statistical regression from the synchronized suspended sediment concentration measurements. Then, the retrieved results from 28 scene MSI images during 2017-2019 are used to analyze the spatiotemporal variation of suspended sediment concentration in rivers and lakes, and the influence of water level variation on their spatial differentiation is also discussed. The results show that:① The retrieval model established by the ratio of the sixth band to the third band of the MSI sensor is suitable for high-turbidity water type, with high accuracy (R2=0.863, RMSE=22.211 mg·L-1). ② Spatially, the suspended sediment concentration near the lake entrances, northwestern parts of the upper and middle lake areas, and the lower lake is relatively higher, and that of Shengjin Lake is lower than that of the Yangtze River overall except for in summer. Temporally, the suspended sediment concentration in Shengjin Lake is relatively lower in summer and higher in other seasons, while the connected Yangtze River section exhibits the opposite intra-annual variation. ③ The water level, which is caused by the connectivity of rivers and lakes under the influence of the sluice, is the key factor affecting the spatial differentiation of suspended sediment concentration in the river and lake system. The suspended sediment concentration in Shengjin Lake contributes to the Yangtze River in dry and normal water periods, and that in the normal water period is more significant. In contrast, during the flood period, the correlation between suspended sediment concentration in the Yangtze River and that in Shengjin Lake is not obvious.

Vitexin protects against ischemia/reperfusion-induced brain endothelial permeability.

Brain endothelial permeability plays a crucial role in blood-brain barrier (BBB), but the permeability enhancement in cerebral ischemia reperfusion (I/R). Vitexin has certain neuroprotective effects, but the effect brain endothelial permeability in I/R injury was unknown. In this study, the effects of Vitexin on endothelial permeability and the underlying mechanisms in human brain microvascular endothelial cells (HBMEc) I/R injury model were investigated. Cell viability, lactate dehydrogenase (LDH), inflammation and apoptosis were detected. The effects of Vitexin on BBB integrity tight junction, matrix metalloproteinases (MMP) were also investigated. The mechanism was confirmed by PI3K inhibitor and NOS inhibitor in normal or eNOS siRNA transfection HBMEc. Vitexin significantly reduced LDH, Caspase 3 level, alleviated inflammation, also could maintain BBB integrity, increased tight junction proteins expression and inhibited MMP. The mechanism is related to reduction of intracellular NO and ONOO-, regulated eNOS, iNOS activity. Vitexin significantly preserved eNOS phosphorylation in response to the activated Akt. Moreover, combined with PI3K inhibitor or low dosage of NOS inhibitor, totally abolished Vitexin-induced eNOS phosphorylation, the protected effect was also attenuated, but still significantly between model cells. However, combined with high dosage NOS inhibitor which both inhibited the eNOS phosphorylation and iNOS, the protected effect of Vitexin was abrogated. In addition, eNOS silencing cells were used to further clarify the regulatory role of Vitexin on iNOS. Our findings showed that Vitexin could play a protective role in I/R-induced brain endothelial permeability by simultaneously increase eNOS phosphorylation and inhibit iNOS.

[Effects of butylphthalide on the apoptosis of PC-12 cells under the induction of ß-amyloid peptide].

OBJECTIVE: To study the protective effects of butylphthalide (NBP) on the Aß(25-35)-induced apoptosis in PC-12 cells. METHODS: The apoptosis of PC-12 cell was analyzed by MTT assay, transmission electron microscope and PI method at different concentrations of NBP (0.1, 1.0, 10, 100 µmol/L) with the addition of Aß or not. The expressions of Bcl-2 and cytochrome C (Cyt-C) were detected by Western blot. RESULTS: As demonstrated by the MTT assay, the values of cell viability were 76.5% ± 1.1%, 84.2% ± 1.3%, 89.5% ± 1.3% and 81.9% ± 1.9% at various concentration (0.1, 1.0, 10, 100 µmol/L) of NBP respectively. The model group was 71.7% ± 1.4%. It was revealed that the former could significantly prevent the cell viability under the induction of Aß(25-35) (P < 0.05). A pretreatment with 10 µmol/L NBP could significantly inhibit the decrease of viability under the induction of Aß(25-35) (P < 0.05). PI showed that the apoptosis rate of the 10 µmol/L NBP treatment group was significantly lower than that of the model group. Under electron microscope, the characteristics of cell apoptosis were significant in the model group. And the cell morphology of the 10 µmol/L NBP treatment group was normal. The expression rate of Bcl-2 protein in the 10 µmol/L NBP treatment group was obviously higher than that in the model group. Cyt-C was weakly expressed in nerve cells of the normal and the 10 µmol/L NBP groups. But it had a strong expression in the model group. CONCLUSION: NBP prevents the injury of PC12 cells by Aß. And the mechanism may be related to the elevated level of Bcl-2 and the inhibited mitochondrial release of Cyt-C.