The association between erector spinae muscle content and chronic heart failure and its severity.

AIMS: Previous studies have shown a significant reduction in skeletal muscle content in patients with chronic heart failure (CHF). The present study focused on the erector spinae muscle (ESM) to determine whether ESM content is associated with the development and severity of CHF. METHODS AND RESULTS: A total of 652 patients were included in this trial for the study. According to the diagnostic criteria of CHF, 652 patients were divided into two groups, namely, the control group (268 patients) and the CHF group (384 patients). Meanwhile, to assess whether the ESM is associated with the severity of CHF, patients in the CHF group were divided into two groups according to left ventricular ejection fraction (LVEF) values: heart failure with preserved ejection fraction (HFpEF, LVEF ≥50%, 256 patients) and heart failure with reduced ejection fraction (HFrEF, LVEF ≤40%, 68 patients). Receiver operating curve analysis was performed to assess whether ESM content could predict CHF and determine its severity. Compared with the control group, the patients in the CHF group were older, the prevalence of coronary heart disease (CHD) and atrial fibrillation was higher, the colour ultrasound results showed that LVEF decreased significantly, and the left ventricular end-diastolic internal diameter and left ventricular end-systolic internal diameter increased significantly. Besides, patients in the CHF group had significantly lower ESM content, and ESM is an independent predictor of heart failure, with an odds ratio of 0.713 (CHF group vs. control group, 95% confidence interval 0.626-0.811, P < 0.001). Compared with the HFpEF group, the HFrEF group has a lower prevalence of CHD, LVEF decreased significantly, the left ventricular end-diastolic internal diameter and left ventricular end-systolic internal diameter increased significantly, also patients in the HFrEF group had significantly lower ESM content compared with patients in the HFpEF group, and ESM is an independent predictor of the severity of heart failure, with an odds ratio of 0.514 (HFrEF group vs. HFpEF group, 95% confidence interval (0.418-0.633, P < 0.05). The results of receiver operating curve analysis showed that the sensitivity and specificity of ESM content for the diagnosis of CHF were 65.6% and 71.6%, respectively, while the sensitivity and specificity of ESM content for predicting the severity of CHF were 47.1% and 89.1%, respectively. CONCLUSIONS: The ESM is of great value in predicting the onset and severity of CHF.

Microcystin-LR exposure enhances toxin-degrading capacity and reduces metabolic diversity of sediment microbial communities.

Substantial outbreaks of cyanobacterial harmful algal blooms (cyanoHABs) are accompanied by the prevalent existence of microcystins (MCs) in eutrophic freshwater worldwide, which can compromise the safety of aquatic ecosystems and public health. However, the response of the sediment microbial community to MCs exposure remains unclear. In this study, the sediment microbial communities of Lake Taihu were continuously exposed to environmentally relevant concentration (10 µg/L) of microcystin-LR (MC-LR) in microcosms for three months to mimic MCs contamination during cyanoHABs. Meanwhile, the MC-LR degradation characteristics, metabolic profiles, functional genes, and structures of microbial communities were analyzed periodically. The results showed that the MC-LR degradation capacities of microbial communities significantly increased with prolonged toxin exposure time. The enhanced MC-LR degradation rate was positively correlated with the increase in the abundance of mlr genes, which corresponds to the MC-degrading bacterial community. However, the MC-LR degradation pathway was maintained, and one new biodegradation intermediate (Adda-Glu) was first identified. Moreover, the metabolic profiles of the microbial communities indicated that overall carbon metabolic activity displayed a stimulation-suppression trend, and the exposure led to different carbon utilization patterns. Furthermore, microbial community structure analysis showed that long-term MC-LR exposure enriched microbes associated with MC degradation (Pseudomonas, Stenotrophomonas, Sphingopyxis and Sphingomonas) but inhibited MC-sensitive bacterial genera. This study clearly elucidates that MC-LR exposure alters the function, metabolism, and structure of the sediment microbial community to adapt to polluted environments.

Insights into the Role of Na+ on the Transformation of Gypsum into α-Hemihydrate Whiskers in Alcohol-Water Systems.

Alcohol-water solution-mediated transformation of gypsum into α-hemihydrate (α-HH) whiskers provides a green alternative for the high-value-added recycling of flue gas desulfurization (FGD) gypsum. However, the role of non-lattice cations during the transformation is still unclear. We report an evolution from "boosting-retarding" to "boosting-retarding-boosting" and finally to "boosting only" effect of non-lattice Na+ functioned by the concentration of ethylene glycol (EG) in water solutions. The driving force increased almost linearly upon the introduction of Na+ through the formation of ion pairs, and a higher slope was obtained at a higher EG concentration. Adsorption of Na+ ions and solidification of eugsterite on gypsum surfaces blocked the nucleation sites of α-HH. The retarding effect first rapidly increased and gradually approached a limit, following a parabolic trend after Na+ ions were introduced. Pentasalt, with a structure similar to that of α-HH, precipitated on the gypsum surface at higher c(Na+). The interaction of the driving force and the structural evolution of calcium sulfate ionic clusters accounts for the evolution of transformation kinetics. The retardation zone was compressed with the increase in EG volume ratios, and a monotonic boosting effect upon Na+ was observed at a 35.0 vol % of EG. Nucleation kinetics dominates the aspect ratio of α-HH whiskers. This study may provide a significant guidance for the utilization of FGD gypsum.

Multiple pathways for the anaerobic biodegradation of microcystin-LR in the enriched microbial communities from Lake Taihu.

Anaerobic biodegradation is a non-negligible elimination approach for microcystin (MC) pollution and exhibits important bioremediation potential for environmental problems. However, the specific anaerobic MC-degrading mechanism remains unclear and few functional bacteria have been found. In this study, three microbial communities of sludges from different locations in Lake Taihu were collected and further enriched by microcystin-LR (MC-LR) under anaerobic conditions. MC-LR (1 mg/L) could be completely degraded by these enriched microbial communities under anaerobic conditions, but their degradation rates were significantly different. In addition, two different ring-opening sites of MC-LR in Ala-Leu and Arg-Adda were observed, and three new anaerobic degradation products were first identified, including two hexapeptides (MeAsp-Arg-Adda-Glu-Mdha-Ala and Adda-Glu-Mdha-Ala-Leu-MeAsp) and one end-product pentapeptide (Glu-Mdha-Ala-Leu-MeAsp). Based on the chemical structures and temporal trends of all detected degradation products, two novel anaerobic biodegradation pathways of MC-LR were proposed. Moreover, the MC-degrading genes mlrABC were not detected among all microbial communities, which suggested that some new MC-degrading mechanisms might exist under anaerobic conditions. Finally, through the comparison of microbial community structure, Gemmatimonas and Smithella were deduced as possible anaerobic MC-degrading bacteria. These findings strongly indicate that anaerobic biodegradation is an important method of self-repair in the natural environment and provides a potential removal strategy for MC pollution.

Removal of microcystins from water and primary treatment technologies - A comprehensive understanding based on bibliometric and content analysis, 1991-2020.

Microcystins are a group of heptapeptide hepatotoxins produced by a variety of algae and are frequently detected in aquatic ecosystems, posing a global threat to ecological stability and human health. However, it is difficult to eliminate them completely and innocuously from water by conventional water treatment processes. This study comprehensively evaluated a total of 821 original articles retrieved from the Web of Science (1991-2020) about the removal of microcystins using bibliometric and content analysis to provide a qualitative and quantitative research landscape and a global view of research hotspots and future research directions. Furthermore, the primary and promising treatment technologies for microcystin pollution were also summarized and discussed. The results indicated an urgent practical demand to remediate microcystin pollution according to the increasing number of publications since 2005. China had the highest number of publications, whereas the United States was the core country in the international collaboration network. The Chinese Academy of Sciences and University of Cincinnati showed their leading positions considering article amounts and academic cooperation. Dionysiou DD contributed the most articles, and Carmichael WW had the highest number of co-citations. Three treatment technologies, including biodegradation, chemical oxidation and adsorption, were the major strategies to remediate the pollution of microcystins in water. In addition, the toxicity of toxins/their metabolites, degradation kinetics, and elimination mechanism were also important research contents. Bacterial degradation, photocatalytic degradation, and multiple-technologies approach have been identified with great potential and should be given more attention in future studies. This work summarizes the current research status on microcystin management, provides a valuable reference for researchers to identify potential opportunities for collaboration in related fields, and guides future research directions to inter-disciplinary and multi-perspective approaches.

Biodegradation of Nodularin by a Microcystin-Degrading Bacterium: Performance, Degradation Pathway, and Potential Application.

Currently, studies worldwide have comprehensively recognized the importance of Sphingomonadaceae bacteria and the mlrCABD gene cluster in microcystin (MC) degradation. However, knowledge about their degradation of nodularin (NOD) is still unclear. In this study, the degradation mechanism of NOD by Sphingopyxis sp. m6, an efficient MC degrader isolated from Lake Taihu, was investigated in several aspects, including degradation ability, degradation products, and potential application. The strain degraded NOD of 0.50 mg/L with a zero-order rate constant of 0.1656 mg/L/d and a half-life of 36 h. The average degradation rate of NOD was significantly influenced by the temperature, pH, and initial toxin concentrations. Moreover, four different biodegradation products, linear NOD, tetrapeptide H-Glu-Mdhb-MeAsp-Arg-OH, tripeptide H-Mdhb-MeAsp-Arg-OH, and dipeptide H-MeAsp-Arg-OH, were identified, of which the latter two are the first reported. Furthermore, the four mlr genes were upregulated during NOD degradation. The microcystinase MlrA encoded by the mlrA gene hydrolyzes the Arg-Adda bond to generate linear NOD as the first step of NOD biodegradation. Notably, recombinant MlrA showed higher degradation activity and stronger environmental adaptability than the wild strain, suggesting future applications in NOD pollution remediation. This research proposes a relatively complete NOD microbial degradation pathway, which lays a foundation for exploring the mechanisms of NOD degradation by MC-degrading bacteria.

[Effect of Long-term Organic Amendments on Nitric Oxide Emissions from the Summer Maize-Winter Wheat Cropping System in Guanzhong Plain].

Agricultural soil is a significant source of nitric oxide (NO). The primary aim of this study was to quantify the effect of long-term organic amendments on NO emissions from the summer maize-winter wheat cropping system in Guanzhong Plain. NO fluxes were regularly measured by the static chamber method for one year (June 2016 to June 2017). Field experiments included four fertilizer treatments that commenced in 1990. The control (CK, 0 kg·hm-2) treatment was unfertilized throughout the years. The fertilized treatments were synthetic fertilizer (NPK, 165 kg·hm-2), synthetic fertilizer plus maize stalk (NPKS, (165+40) kg·hm-2), and synthetic fertilizer plus dairy manure (NPKM, (50+115) kg·hm-2) during the winter wheat season. They were fertilized with synthetic fertilizer (188 kg·hm-2) during the summer maize season. The results showed small NO emission [<12.2 g·(hm2·d)-1] from the CK treatment within the experimental period. Large NO fluxes [up to 112.0 g·(hm2·d)-1 in NPK treatment] were captured following sowing and fertilization during the summer maize season and following fertilization during the winter wheat season for all fertilized treatments. Annual NO emissions and direct emission factors ranged from 0.13 to 0.57 kg·hm-2 and from 0.04% to 0.12%, respectively. Annual NO emissions from the NPKS and NPKM treatments were 17.6% lower and 68.0% (P<0.05) larger than those from the NPK treatment, respectively. Seasonal NO emissions from the NPKS and NPKM treatments were 41.1%-60.0% (P<0.05) lower than those from the NPK treatment during the winter wheat season, indicating that organic amendments reduced NO emissions. Seasonal NO emissions from the NPKS and NPKM treatments were 25.2%-292.1% (P<0.05) larger than that from the NPK treatment during the summer maize season, mostly due to the positive effect of soil organic matter content on NO emissions.

Trade-off between soil organic carbon sequestration and nitrous oxide emissions from winter wheat-summer maize rotations: Implications of a 25-year fertilization experiment in Northwestern China.

The primary aims of this study were to (i) quantify the variations in nitrous oxide (N2O) emissions and soil organic carbon (SOC) sequestration rates under winter wheat-summer maize cropping systems in Guanzhong Plain and (ii) evaluate the impact of organic amendments on greenhouse gas mitigation over a long-term period. We measured N2O fluxes during the maize season in 2015 under four fertilizer regimes in a long-term fertilization experiment. Soil was treated with only synthetic fertilizers in the maize season and with synthetic fertilizers, synthetic fertilizers plus crop residues and synthetic fertilizers plus low and high levels of dairy manure in the winter wheat season from 1990. The SOC content (0-20cm) was collected annually at the same site between 1990 and 2015. Synthesis of our measurements and previous observations (between 2000 and 2009) within the investigated agricultural landscape revealed that cumulative N2O emissions increased with the SOC content following natural logarithm models during both the maize and winter wheat seasons (r2>0.77, p<0.001), implying a trade-off between N2O emissions and SOC sequestration. The SOC content increased under all fertilizer regimes, and the dynamics were well fitted by the linear and logistic regression models (r2>0.74, p<0.001), indicating that all the fertilizer treatments in this study sequestered SOC. By applying these regression models, we estimated that the two manure-amended treatments accumulated a negative global warming potential (ranging from -1.9 to -12.9tCO2-equivalentha-1) over the past 25years. However, this benefit would most likely be offset by high N2O emissions at saturated SOC levels before 2020. Our estimates suggest that organic amendments may not be efficient for greenhouse gas mitigation in Guanzhong Plain over a long-term period. We recommend efforts to inhibit N2O production via denitrification as being critical to resolving the conflict between SOC sequestration and N2O emissions.

[Effects of Long-term Organic Amendments on Soil N2 O Emissions from Winter Wheat-maize Cropping Systems in the Guanzhong Plain].

The primary aim of this study was to quantify the effects of long-term organic amendments on soil nitrous oxide (N2O) emissions. Using static chamber-gas chromatograph technique, we measured N2O fluxes from winter wheat-maize rotation system and related environmental factors in the Guanzhong Plain for one year (October 2014 to October 2015). Field experiments were based on the "Chinese National Loess Fertility and Fertilizer Effects Long-term Monitoring Experiment". Four treatments were control (CK, 0 kg·hm-2), NPK (NPK, 353 kg·hm-2), NPK combined with maize straw[NPKS, (353+40) kg·hm-2] and cattle waste[NPKM, (238+115) kg·hm-2]. During the experimental period, N2O fluxes from CK treatment were small[<2.9 g·(hm2·d)-1]; while emissions from fertilized treatments peaked after fertilization[up to 113.4 g·(hm2·d)-1 for NPKS] and irrigation[up to 495.0 g·(hm2·d)-1 for NPKM] during winter wheat and maize seasons, respectively. N2O flux was significantly correlated to soil water-filled pore space for all treatments (r>0.28,P<0.05). Annual N2O emissions were (0.1±0.0), (2.6±0.1), (3.4±0.7) and (2.9±0.3) kg·hm-2 for CK, NPK, NPKS and NPKM, respectively. The fertilized treatments released higher N2O emissions than CK treatment (P<0.05), indicating that fertilization stimulated N2O emissions. However, the differences in N2O emissions were not significant among the fertilized treatments (P=0.06), suggesting that organic amendments did not increase N2O emissions obviously. The direct emission factors were 0.72%, 0.83% and 0.80% for NPK, NPKS and NPKM, respectively, all of which were lower than the IPCC default of 1%. The yield-scaled N2O emission for NPKM was the lowest among the fertilized treatments.