Effects of fresh-salt water interaction on spatial variations of soil organic carbon in reed wetland of Yellow River Estuary.

Estuarine wetlands exhibit significant interaction between fresh and salt water, with long-term carbon sequestration capability. We set up 60 sampling sites in the reed wetlands of the fresh-salt water interaction zone of the Yellow River Estuary, covering four different zones of the weak-intensity fresh-salt water interaction zone (WIZ), medium-intensity fresh-salt water interaction zone (MIZ), high-intensity interaction fresh-salt water zone (HIZ) and strong-intensity fresh-salt water interaction zone (SIZ). We investigated how fresh-salt water interaction affected the spatial variation of soil organic carbon (SOC) storage. The results showed that the area of reed wetland accounted for 17.8% of the total area of the fresh-salt water interaction zone the Yellow River Estuary, which mainly distributed in the WIZ and MIZ. The SOC content of reed wetland in the fresh-salt water interaction zone ranged from 1.09 to 3.65 g·kg-1, the SOC density was between 1.85-5.84 kg·m-2, and the SOC storage was (17.32±3.64)×104 t. The SOC content and SOC density decreased with increasing fresh-salt water interaction. There were significant differences in surface SOC content between different subzones of the fresh-salt water interaction zone. The surface SOC content decreased significantly with the increases of fresh-salt water interaction intensity. SOC density was positively correlated with SOC, TN, NH4+-N, and biomass, but negatively correlated with salt ions, soil bulk density, pH, and EC. SOC storage in the 0-30 cm soil layer accounted for 50.9%-64.2% of that in the 0-60 cm soil layer, while SOC storage in the 0-60 cm soil layer occupied 19.1%-37.7% of that in the 0-400 cm soil layer. The results could provide a scientific basis for accurately evaluating SOC storage of estuarine wetlands, improving carbon sink function and wetland management.

Effects of tidal hydrology on soil phosphorus forms in the Yellow River estuary wetland: A field study of soil core translocation.

Phosphorus (P) forms in soil are related to the P cycle and play an important role in maintaining the productivity and function of wetlands. Tidal hydrology is a key factor controlling soil P forms in estuary wetlands; however, the response of soil P forms to tidal hydrological changes remains unclear. A translocation experiment in the Yellow River Estuary wetland was conducted to study the effect of hydrological changes on P forms in the soil, in which freshwater marsh soils in the supratidal zone were translocated to salt marshes in different intertidal zones (up-high-tidal zone, high-tidal zone, and middle-tidal zone). Over a 23-month experiment, soil properties showed varying changes under different tidal hydrology conditions, with an increase in pH, salinity, Ca2+ and salt ions and a decrease in iron oxide and nutrients. Compared with the control, the content of different forms of phosphorus (total phosphorus, inorganic phosphorus, organic phosphorus, and calcium-bound phosphorus) in the cultured soil cores decreased from 3.3 % to 67.0 % in the intertidal zones, whereas the content of ferrum­aluminum-bound phosphorus increased from 58.9 % to 65.1 % at the end of the experiment. According to the partial least squares structural equation model, P forms are influenced by tidal hydrology mainly through the mediation of salt ions and nutrient levels. These results suggest that seawater intrusion promotes the release of P in the supratidal zone soil of estuary wetlands.

cFLIPL alleviates myocardial ischemia-reperfusion injury by regulating pyroptosis.

Alleviating myocardial ischemia-reperfusion injury (MIRI) plays a critical role in the prognosis and improvement of cardiac function following acute myocardial infarction. Pyroptosis is a newly identified form of cell death that has been implicated in the regulation of MIRI. In our study, H9c2 cells and SD rats were transfected using a recombinant adenovirus vector carrying cFLIPL , and the transfection was conducted for 3 days. Subsequently, H9c2 cells were subjected to 4 h of hypoxia followed by 12 h of reoxygenation to simulate an in vitro ischemia-reperfusion model. SD rats underwent 30 min of ischemia followed by 2 h of reperfusion to establish an MIRI model. Our findings revealed a notable decrease in cFLIPL expression in response to ischemia/reperfusion (I/R) and hypoxia/reoxygenation (H/R) injuries. Overexpression of cFLIPL can inhibit pyroptosis, reducing myocardial infarction area in vivo, and enhancing H9c2 cell viability in vitro. I/R and H/R injuries induced the upregulation of ASC, cleaved Caspase 1, NLRP3, GSDMD-N, IL-1ß, and IL-18 proteins, promoting cell apoptosis. Our research indicates that cFLIPL may suppress pyroptosis by strategically binding with Caspase 1, inhibiting the release of inflammatory cytokines and preventing cell membrane rupture. Therefore, cFLIPL could potentially serve as a promising target for alleviating MIRI by suppressing the pyroptotic pathway.

[Effects of Water-salt Environment on Freshwater Wetland Soil C, N, and P Ecological Stoichiometric Characteristics in the Yellow River Estuary Wetland].

Carbon (C), nitrogen (N), and phosphorus (P) are important nutrients, and their ecological stoichiometric characteristics can reflect the quality and fertility capacity of soil, which is critical to understanding the stable mechanisms of estuarine wetland ecosystems. Under global changes, the increase in salinity and flooding caused by sea level rise will lead to changes in biogeochemical processes in estuarine wetlands, which is expected to affect the ecological stoichiometric characteristics of soil C, N, and P and ultimately interfere with the stability of wetland ecosystems. However, it remains unclear how the C, N, and P ecological stoichiometric characteristics respond to the water-salt environment in estuarine wetlands. We differentiated changes in the C, N, and P ecological stoichiometric characteristics through an ex-situ culture experiment for 23 months in the Yellow River Estuary Wetland. The five sites with distinct tidal hydrology were selected to manipulate translocation of soil cores from the freshwater marsh to high-, middle-, and low-tidal flats in June 2019. The results showed that soil water content (SWC); electrical conductivity (EC); and C, N, and P ecological stoichiometric characteristics of freshwater marsh soil significantly changed after translocation for 23 months. SWC decreased on the high- and middle-tidal flats (P<0.05) and increased on the low-tidal flat (P<0.05). EC increased to different degrees on all three tidal flats (P<0.05). Soil total organic carbon (TOC) and total nitrogen (TN) were significantly lower on the high-tidal flat (P<0.05), whereas total phosphorus (TP) was significantly lower on the middle- and high-tidal flats (P<0.05). C:N was decreased on the high- and middle-tidal flats (P<0.05); C:P and N:P were lower on the high-tidal flat; and all C, N, and P ecological stoichiometric characteristics showed no change on the low-tidal flat (P>0.05). Pearson's analysis showed that the ecological stoichiometric characteristics of C, N, and P were related to some properties of soil over the culture sites. The PLS-SEM model showed that the water-salt environment had different effects on soil C:N, C:P, and N:P through the main pathways of negative effects on soil TOC and TP. The results suggest that sea level rise may impact the C, N, and P ecological stoichiometric characteristics in freshwater marsh soil, resulting in some possible changes in the nutrient cycles of estuarine wetlands.

Liraglutide Attenuates Myocardial Ischemia/Reperfusion Injury Through the Inhibition of Necroptosis by Activating GLP-1R/PI3K/Akt Pathway.

Necroptosis is a crucial programmed cell death that is tightly associated with myocardial ischemia/reperfusion injury (MI/RI). Liraglutide is an effective option for the treatment of type 2 diabetes and has recently been reported to exert cardioprotective effects on MI/RI. Researchers do not know whether the cardioprotective effect of liraglutide is involved in regulating necroptosis. This study aimed to explore the effect of liraglutide on MI/RI-induced necroptosis and its potential mechanisms. Hypoxia/reoxygenation (H/R) was performed on H9c2 cells in vitro to simulate ischemia/reperfusion (I/R) injury, and an MI/RI rat model was established in vivo by ligating the anterior descending branch of the left coronary artery. H/R or I/R damage was assessed by performing biochemical assay, Hoechst 33342/PI staining, H&E (hematoxylin and eosin) staining, and Annexin-V/PI staining. Our data revealed that liraglutide resulted in markedly increased cell viability and reduced cardiac enzyme release by protecting cardiomyocytes from a necrosis-like phenotype after H/R. The myocardial infarct size and cardiac enzyme release were reduced in the heart tissues from the liraglutide-treated group. The levels of necroptosis-associated proteins (receptor-interacting protein kinase 3 (RIPK3), p-RIPK3, and phosphorylated-mixed lineage kinase domain-like protein (p-MLKL)) were also reduced by the liraglutide treatment. Mechanistically, we revealed that liraglutide exerted cardioprotective effects through a glucagon-like peptide-1 receptor (GLP-1R) and phosphatidylinositol-3 kinase (PI3K)-dependent pathway. Both the GLP-1R inhibitor exendin (9-39) and the PI3K inhibitor LY294002 abrogated the protective effects of liraglutide in vitro. We found that liraglutide may attenuate MI/RI by inhibiting necroptosis, in part by enhancing the activity of the GLP-1R/PI3K/Akt pathway.

Clinical efficacy of sacubitril-valsartan combined with acute ST-segment elevation myocardial infarction after reperfusion: A systematic review and meta-analysis.

Background: Several studies have investigated the combined use of sacubitril- valsartan after reperfusion in acute ST-segment elevation myocardial infarction (STEMI). However, the sample sizes of these studies were small and their results were somewhat heterogeneous. To determine the effect of sacubitril-valsartan on myocardial ischemia-reperfusion. Methods: Search PubMed, EMbase, Web of Science and The Cochrane Library, CNKI database, VIP database and Wanfang digital journal full-text database for eligible articles from their date of inception up to April, 2022. All data were meta-analyzed using Review Manager 5.3 and STATA 16.0 software. Results: A total of 23 studies including 2,326 patients with acute STEMI were included. These results of this meta-analysis indicated that left ventricular ejection fractions (LVEF) value within 6 months after surgery (OR, 4.29; 95% confidence interval, 3.78-4.80; P < 0.00001), left ventricular end-diastolic diameter (LVEDD) value within 6 months after surgery (OR, -3.11; 95% CI, -3.87 to -2.35; P < 0.00001) and left ventricular end-diastolic volume (LVEDV) value 6 months after operation (OR, -6.22; 95% CI, -7.10 to -5.35; P < 0.00001) are better than without sacubitril and valsartan. Conclusion: To sum up the above, the results of this study suggest that sacubitril- valsartan can reduce the reperfusion injury of ischemic myocardium by improving cardiac function within a follow-up period of 6 months.

[Spatial Distribution and Eco-stoichiometric Characteristics of Soil Nutrient Elements Under Different Vegetation Types in the Yellow River Delta Wetland].

To clarify the distribution characteristics and the ecological stoichiometric characteristics of nutrient elements in soils under different vegetation types, four typical natural wetlands, i.e., Phragmites australis wetland, Tamarix chinensis wetland, Suaeda salsa wetland, and Tidal flat wetland, as well as Gossypium spp. fields that were reclaimed from natural wetlands, were selected as study sites in the Yellow River Delta, and comparisons between the agricultural reclamation land and natural wetlands were conducted. The results showed that the soil total organic carbon (TOC) and total nitrogen (TN) contents in the natural wetlands were as follows:P. australis wetland and T. chinensis wetland>S. salsa wetland>Tidal flat, and the contents of TOC and TN were significantly negatively related to electrical conductivity (EC) and pH values (P<0.05). The contents of TOC, TN, and total phosphorus (TP) in Gossypium spp. fields were significantly higher than those in natural wetlands (P<0.05), especially the contents of nitrate nitrogen (NO3--N) in Gossypium spp. fields, which were 9.4-11.4 times that of natural wetlands. However, no significant correlations between TOC, TN, and TP and EC and pH values (P>0.05) were observed in Gossypium spp. fields. The results of correlation analysis showed that the C/N of natural wetlands were mainly controlled by the contents of TN (P<0.05), and the C/N of the Gossypium spp. fields were significantly lower than those of natural wetlands (P<0.05). The soil C/P and N/P of natural wetlands and Gossypium spp. fields in the Yellow River Delta were low, and the variation trends were consistent with those of soil TOC and TN. Comparative analysis revealed, on the whole, that there were significantly different soil nutrient element contents, C/N, C/P, and N/P in Gossypium spp. fields compared to those of natural wetlands (P<0.05). The process of reclamation could significantly change the spatial distribution of nutrient elements in wetlands. Our results should be of importance in revealing the biogeochemical process of soil nutrient elements in coastal wetland and the influence of agricultural reclamation activities on the differentiation of soil nutrient elements.

Elemental stoichiometry (C, N, P) of soil in the Yellow River Delta nature reserve: Understanding N and P status of soil in the coastal estuary.

The Yellow River Delta Nature Reserve (YNR), which includes two separated regions: part of the old Yellow River Delta (OYD) and part of the current Yellow River Delta (CYD), was established to protect coastal wetlands in the coastal estuary. A total of 120 plots were sampled in the YNR in April 2016, and the spatial patterns of soil C, N and P contents and their stoichiometric ratios (C:N (RCN), C:P (RCP) and N:P (RNP)) were studied and interpolated using the Ordinary Kriging method. Results indicated that the soil elemental contents and stoichiometric ratios showed high spatial heterogeneity and large variations. The mean C:N:P ratio (RCNP) was ~ 64.7:2.3:1 in OYD, and ~ 64.5:2.0:1 in CYD, respectively, and a well-constrained RCP ratio ~ 65:1 was found in the 0-50 cm soil depth within the YNR. N showed greater variation than C and P. Furthermore, N contents in the 0-5 cm soil layer of OYD were significantly higher than that of CYD (F = 4.79, p = 0.03); RCN in 0-5 cm, 5-10 cm layers of OYD was significantly lower than those in the same layers of CYD (F = 4.75, p = 0.03; F = 5.18, p = 0.02, respectively). RNP in 0-5 cm soil layer of OYD was notably higher than that of CYD (F = 4.88, p = 0.03). These results were due to the combined actions of sedimentation, reclamation and fertilization. Finally, we concluded that a longer reclamation and fertilization history led to decreased RCN in coastal estuary soils, confirmed that the soil of the YNR exhibits N limitation, and suggested that the soil RCN and RNP could be good indicators of the anthropogenic improvement status during soil development in this coastal estuary.

Environmental threats induced heavy ecological burdens on the coastal zone of the Bohai Sea, China.

The environment of the Bohai Sea is under enormous pressure because of rapid economic and urban development associated with increased population inhabiting the coastal zone. Environmental threats to the coastal ecosystem were analyzed using 2006-2017 statistical/monitoring data from the State Oceanic Administration, China. The results showed that harmful algal blooms occurred a total of 104 times during the period of 2006-2017, for a cumulative area of more than 21,275 km2. The main environmental threats came from offshore oil and gas production in the form of hydrocarbon pollution during extraction, as well as from urban wastewater and sewage. Oil pollution, mainly generated from spills, offshore oil platforms and large number of vessels/ports, was found to cause very severe negative impacts on the environment. Another threat is from excessive groundwater exploitation which has resulted in seawater intrusion and soil salinization occurrence in more than 90% of coastal areas around the Bohai Sea. The maximum distance of intrusion by seawater and soil salinization was more than 40 and 32 km inland, respectively. Contamination by terrestrial pollutants was identified as another threat affecting the environment quality of the Bohai Sea. Approximately 840,000 t of pollutants were carried into the sea by major rivers annually for 2010-2017. The standard discharge rate of terrestrial-source sewage outlets did not exceed 50%; however, only 13.12% of sea areas adjacent to sewage outlets (rivers) met the environmental quality requirements for functional marine areas. The results also showed the frequency of storm surges in the Bohai Sea which was 8.83 times per year and the resulting annual direct economic losses reached (RMB) 1.77 billion for 2006-2017. The results highlight the urgent need to implement an ecological management strategy to reduce the heavy ecological burdens in the coastal zone of the Bohai Sea.

Impacts of inland pollution input on coastal water quality of the Bohai Sea.

Inland pollutants input is a key impact factor for the coastal water quality of the Bohai Sea. The coastal and inland water pollutant inputs were analyzed by using monitoring data of recent years from the State Oceanic Administration. The results showed that more than 56% of the Bohai Sea area was unclean seawater in 2012, although the water quality improved gradually after that time. In 2017, about one-third of the Bohai Sea area still had unclean seawater. Inorganic nitrogen, reactive phosphate, and petroleum hydrocarbons are the main pollutants in the seawater. A total of approximately 840,000 t of pollutants was transported to the sea each year by major rivers during 2010-2017. Significant correlations (p < 0.05) were found between the third-grade level seawater area and the pollutants of CODcr, petroleum, NO3--N, NH4+-N, NO2--N, Cu, and Pb and between the inferior fourth-grade level seawater area and the pollutants of petroleum, NO2--N, Pb, and NO3--N. The standard discharge rate of terrestrial-source sewage outlets was no more than 50%. The low standard discharge rate of the major terrestrial-source sewage pollutants of CODcr, NH4+-N, TP, BOD5, and SS caused more than 80% of the monitored sea areas adjacent to the selected key sewage outlets to not meet the water quality requirements of the marine functional area. The results suggest that implementing a coastal water management plan is necessary to reduce the heavy ecological burdens on the coastal zone of the Bohai Sea.

Duration of dual antiplatelet therapy after percutaneous coronary intervention with implantation of second-generation drug-eluting stent: A meta-analysis of randomized controlled trials.

Objective: The optimal duration of dual antiplatelet therapy (DAPT) in patients after PCI with implantation of a drugeluting stent is still controversial. We conducted a meta-analysis to compare the efficacy and safety of short term DAPT (≤ 3 months) followed by P2Y12 inhibitor monotherapy and standard DAPT (12 months) after PCI. Method: Relevant studies published in Medline, Embase, CoChrane Library were searched for randomized controlled trials (RCTs) until November 2019. Studies were screened by selection criteria then quality assessed through the Cochrane Collaboration's tool. Data were extracted from the included studies and statistically analyzed by RevMan 5.3 software. Results: Five RCTs (n=18,357) were included. Compared with standard DAPT, the short term DAPT was associated with a significant decrease in the major bleeding [odds ratio (OR)=0.43, 95% Confidence Interval (CI):0.32-0.58, P <0.00001] and any bleeding [OR=0.56, 95%CI:0.47-0.66, P<0.00001]. There were no significant differences in all-cause death [OR=0.91, 95%CI:0.71-1.16, P =0.45], major adverse cardiac and cerebrovascular event [OR=1.01, 95%CI:0.87-1.17, P =0.91] and stent thrombosis [OR=0.97, 95%CI:0.61-1.54, P =0.91] between with the short term DAPT group and the standard DAPT group. Conclusions: Short term DAPT followed by P2Y12 monotherapy could reduce the risk of bleeding without increasing the incidence of ischemic events after PCI with implantation of second-generation DES compared with standard DAPT. Therefore, short term DAPT may be a promising strategy to balance ischemic events and bleeding complications in patients after PCI.

Soil seed bank and vegetation differences following channel diversion in the Yellow River Delta.

Vegetation plays a key role in influencing the morphodynamics of river deltas, yet channelization of most of the world's rivers limits delta movement and resulting vegetation patterns. Thus, our understanding of vegetation dynamics in newly formed and abandoned deltaic wetlands is still poor. The artificial channel diversion of the mouth of the Yellow River in 1996 created conditions that mimic a natural delta lobe shift by increasing freshwater, sediment, and nutrient supply to wetlands along the new Yellow River course (NYR) and allowing seawater encroachment in the abandoned Yellow River course (OYR). To examine the effects of this river channel shift on the vegetation and seed bank structure, above-ground vegetation and seed bank species richness and diversity were examined from the channel to the marsh interior in wetlands of both OYR and NYR. A total of 17 plant species were found growing across both sites, 9 species were in OYR and 16 species in NYR. Soil depth did not influence seed bank density in OYR, but the seed bank density in the 0-5 cm soil layer was significantly greater than in the 5-10 cm soil layer in NYR. Species diversity of the vegetation and soil seed bank was strongly influenced by soil salinity and hydrology, which varied along the gradient from seaside to river bank. There was a greater separation in species composition between seed bank and vegetation in the OYR than in the NYR. The findings suggest that channel diversion of the Yellow River Had a significant effect to the above-ground vegetation. However, the species richness and diversity of soil seed banks in the OYR was similar to that of the NYR, indicating that seed banks had a greater tolerance to external disturbance compared with vegetation.

Effect of salinity on soil respiration in relation to dissolved organic carbon and microbial characteristics of a wetland in the Liaohe River estuary, Northeast China.

Increasing salinity has important impacts on biogeochemical processes in estuary wetlands, with the potential to influence the soil respiration, dissolved organic carbon (DOC) and microbial population. However, it is unclear how soil respiration is related to changes in the DOC and microbial community composition with increasing salinity. In this study, soil cores were sampled from a brackish wetland in the Liaohe River estuary and treated by salinity solutions at four levels (fresh water, 3‰, 5‰, and 10‰). Samples of gas, water and soil were collected to determine the respiration rates and microbial community structure of the soil and the DOC leaching from the soil. Compared to the low-salinity treatments (fresh water and 3‰), the high-salinity treatments (5‰ and 10‰) decreased the soil respiration rates by 45-57% and decreased the DOC concentrations by 47-55%. However, no significant differences were observed within the low-salinity treatments nor the high-salinity treatments. There is a positive correlation between the soil respiration rates and DOC concentrations in all treatments, but it does not indicate a genetic cause-effect relationship between them. The microbial community structure varied with the salinity level, with higher ß- and δ-Proteobacteria abundance, as well as higher Anaerolineae, and lower Clostridia abundance in the high-salinity treatments. The respiration rates were slightly negatively related to the richness of Proteobacteria and positively related to the richness of Clostridia. This study suggests that there may be a salinity threshold (3-10‰) impacting the organic carbon loss from estuarine brackish wetlands. In addition, the response of soil respiration to increasing salinity may be mainly linked to changes in the microbial community composition rather than changes in the DOC quantity.

Distribution of carbon, nitrogen and phosphorus in coastal wetland soil related land use in the Modern Yellow River Delta.

The delivery and distribution of nutrients in coastal wetland ecosystems is much related to the land use. The spatial variations of TOC, TN, NH4+-N, NO3--N and TP and associated soil salinity with depth in 9 kinds land uses in coastal zone of the modern Yellow River Delta (YRD) was evaluated based on monitoring data in field from 2009 to 2015. The results showed that the average contents of soil TOC, TN, NO3--N, NH4+-N and TP were 4.21 ± 2.40 g kg-1, 375.91 ± 213.44, 5.36 ± 9.59 and 7.20 ± 5.58 and 591.27 ± 91.16 mg kg-1, respectively. The high N and C contents were found in cropland in southern part and low values in natural wetland, while TP was relatively stable both in profiles and in different land uses. The land use, land formation age and salinity were important factors influencing distributions of TOC and N. Higher contents of TOC and N were observed in older formation age lands in whole study region, while the opposite regulation were found in new-born natural wetland, indicating that the anthropogenic activities could greatly alter the original distribution regulations of nutrients in coastal natural wetlands by changing the regional land use.