Enhancing phosphorus source apportionment in watersheds through species-specific analysis.

Phosphorus (P) is a pivotal element responsible for triggering watershed eutrophication, and accurate source apportionment is a prerequisite for achieving the targeted prevention and control of P pollution. Current research predominantly emphasizes the allocation of total phosphorus (TP) loads from watershed pollution sources, with limited integration of source apportionment considering P species and their specific implications for eutrophication. This article conducts a retrospective analysis of the current state of research on watershed P source apportionment models, providing a comprehensive evaluation of three source apportionment methods, inventory analysis, diffusion models, and receptor models. Furthermore, a quantitative analysis of the impact of P species on watersheds is carried out, followed by the relationship between P species and the P source apportionment being critically clarified within watersheds. The study reveals that the impact of P on watershed eutrophication is highly dependent on P species, rather than absolute concentration of TP. Current research overlooking P species composition of pollution sources may render the acquired results of source apportionment incapable of assessing the impact of P sources on eutrophication accurately. In order to enhance the accuracy of watershed P pollution source apportionment, the following prospectives are recommended: (1) quantifying the P species composition of typical pollution sources; (2) revealing the mechanisms governing the migration and transformation of P species in watersheds; (3) expanding the application of traditional models and introducing novel methods to achieve quantitative source apportionment specifically for P species. Conducting source apportionment of specific species within a watershed contributes to a deeper understanding of P migration and transformation, enhancing the precise of management of P pollution sources and facilitating the targeted recovery of P resources.

Risk control and assessment of sulfide-rich sediment remediation by controlled-release calcium nitrate.

Nitrate stimulation is widely used in sediment remediation to eliminate sulfides, degrade organic pollutants and immobilize phosphorus. However, the environmental risks of nitrate escape and the subsequent release of pollutants (e.g. nitrite, ammonium and trace metals) to water bodies during its application has received less attention. In this study, controlled-release nitrate pellets (SedCaN pellets) were manufactured and applied at different sediment depths to examine their effectiveness in controlling the risk of nitrate escape and subsequent pollutant release. The germination of submerged plant was also analyzed to assess the ecological risks associated with the remediated sediment. The results showed that the SedCaN pellets slowly released calcium nitrate, which led to denitrifying sulfide oxidation, organic matter degradation and the immobilization of phosphorus as a calcium-bound species. Gas production by denitrification increased the sediment porosity (0.3-2.2%) and led to the concomitant release of nitrite, ammonium, and heavy metals, creating secondary risks. Application of the SedCaN pellets at depth decreased the nitrate escape and the secondary risks, presumably by means of a capping effect of the upper sediment. The release of nitrate, ammonium, Ni and Cu were partially limited by 91.6%, 19.0%, 61.6% and 57.4% when SedCaN pellets were incorporated into deeper sediments (7-9 cm). Moreover, the range of sulfide oxidation extended to the upper and lower sediments in the profile (column), while the sulfide oxidation efficiency reached 85.9-95.0%. Finally, increased germination of Bacopa monnieri (20.0-26%) demonstrated that in comparison to reference materials the ecological risks of the treated sediments was reduced and the habitat function of sediment was restored after nitrate-stimulating remediation. The results of this study provide valuable guidelines for nitrate-stimulating remediation of sulfide-rich (black-odor) sediments.

Implications of phosphorus partitioning at the suspended particle-water interface for lake eutrophication in China's largest freshwater lake, Poyang Lake.

Nutrient partition, especially for phosphorus (P), has been prominently changed that was caused by variation of river-lake relationship during the post-Three Gorges Reservoir and catchment alternations. Changes in proportion of total particulate phosphorus (TPP) and total dissolved phosphorus (TDP) might accelerate lake eutrophication, but limited attention has been paid to P partition over suspended particle (SP) levels. Data analysis showed that SP concentration presented a positive effect on TPP in wet season and soluble reactive phosphorus (SRP) in dry season, indicating seasonal physical and chemical variations. Based on this phenomenon, we proposed a hypothesis that the SP levels would affect TDP and TPP proportions by partition in aqueous-solid. It was found that using the parabola models to fit the sorption relationships of SRP and TDP (R2 > 0.6, p < 0.01), the maximum sorption capacity (Qmax) was 64.54 mg/kg and 60.52 mg/kg at 400 mg/L of SP level, respectively. In addition, the partition coefficients (KP) of TDP and SRP were logarithmically increased with SP levels, indicating that higher SP levels (>400 mg/L) would hinder the sorption process. Furthermore, enhancing turbulence lead to less sorption of SRP and TDP at high SP levels (>800 mg/L). The sorption of SRP and TDP related to the presence of Fe/Al oxy-hydroxides were enriched in the Fe/Al-P fraction (47% of TP). The findings of this study indicated that the low SP levels would increase P bioavailability for alga and is not conducive for lake eutrophication management.

Military-related posttraumatic stress disorder and mindfulness meditation: A systematic review and meta-analysis / 中华创伤杂志(英文版)

PURPOSE@#Posttraumatic stress disorder (PTSD) is a significant global mental health concern, especially in the military. This study aims to estimate the efficacy of mindfulness meditation in the treatment of military-related PTSD, by synthesizing evidences from randomized controlled trials.@*METHODS@#Five electronic databases (Pubmed, EBSCO Medline, Embase, PsychINFO and Cochrane Library) were searched for randomized controlled trials focusing on the treatment effect of mindfulness meditation on military-related PTSD. The selection of eligible studies was based on identical inclusion and exclusion criteria. Information about study characteristics, participant characteristics, intervention details, PTSD outcomes, as well as potential adverse effects was extracted from the included studies. Risk of bias of all the included studies was critically assessed using the Cochrane Collaboration's tool. R Statistical software was performed for data analysis.@*RESULTS@#A total of 1902 records were initially identified and screened. After duplicates removal and title & abstract review, finally, 19 articles in English language with 1326 participants were included through strict inclusion and exclusion criteria. The results revealed that mindfulness meditation had a significantly larger effect on alleviating military-related PTSD symptoms compared with control conditions, such as treatment as usual, present-centered group therapy and PTSD health education (standardized mean difference (SMD) = -0.33; 95% CI [-0.45, -0.21]; p < 0.0001). Mindfulness interventions with different control conditions (active or non-active control, SMD = -0.33, 95% CI [-0.46, -0.19]; SMD = -0.49, 95% CI [-0.88, -0.10], respectively), formats of delivery (group-based or individual-based, SMD = -0.30, 95% CI [-0.42, -0.17], SMD = -0.49, 95% CI [-0.90, -0.08], respectively) and intervention durations (short-term or standard duration, SMD = -0.27, 95% CI [-0.46, -0.08], SMD = -0.40, 95% CI [-0.58, -0.21], respectively) were equally effective in improving military-related PTSD symptoms.@*CONCLUSION@#Findings from this meta-analysis consolidate the efficacy and feasibility of mindfulness meditation in the treatment of military-related PTSD. Further evidence with higher quality and more rigorous design is needed in the future.

Comparative effectiveness of early versus delayed metformin in the treatment of type 2 diabetes.

AIM: The purpose of this study was to evaluate the effectiveness of early versus delayed initiation of metformin in type 2 diabetes. METHODS: We identified 2925 new users of metformin with type 2 diabetes between 2005 and 2012 in the electronic health records of an integrated health system in Northern California. Patients were matched 1:1 on the propensity for receiving early treatment (defined as ≤6 months from first evidence of diabetes). We evaluated the effectiveness of early versus delayed metformin treatment on intermediate clinical outcomes indicated by changes in hemoglobin A1c (HbA1c) and body mass index (BMI), as well as the incidence of therapy intensification (addition or substitution of a second antihyperglycemic agent). RESULTS: A total of 2144 propensity-score matched patients were included in the early or delayed treatment group (n=1072, in each). Early treatment was associated with significantly larger decreases in HbA1c (-0.36%; 95% confidence intervals [CI]: -0.44 to -0.27%; P<0.001) and BMI (-0.46 kg/m(2); 95% CI: -0.64 to -0.29 kg/m(2); P<0.001) relative to delayed treatment. Patients receiving early treatment also had a greater likelihood of attaining an HbA1c<7% (<53 mmol/mol) (odds ratio: 2.00; 95% CI: 1.63-2.45; P<0.001) and a reduced risk of therapy intensification (hazard ratio: 0.72; 95% CI: 0.61-0.85; P<0.001). CONCLUSIONS: Treatment with metformin earlier in the course of type 2 diabetes is associated with better glycemic control, more pronounced weight reduction, and a lower risk for therapy intensification than delayed treatment. Antihyperglycemic therapy should be initiated early after diagnosis to achieve optimal outcomes.