The influence of wet-to-dry season shifts on the microbial community stability and nitrogen cycle in the Poyang Lake sediment.

In lake environments, seasonal changes can cause exposure of the lake sediment, leading to soil formation. Although previous studies have explored how environmental changes influence microbial functioning in the water-level-fluctuating zone, few studies have investigated how wholescale habitat changes affect microbial composition, community stability and ecological functions in lake environments. To address this issue, our study investigated the effects of sediment-to-soil conversion on microbial composition, community stability and subsequent ecological functioning in Poyang Lake, China. Our results revealed that, during sediment-to-soil conversion, the number of total and unique operational taxonomic units (OTUs) decreased by 40 % and 55 %, respectively. Moreover, sediment-to-soil conversion decreased the microbial community connectivity and complexity while significantly increasing its stability, as evidenced by increased absolute values of negative/positive cohesion. In sediment and soil, the abundance of dominant bacteria, and bacterial diversity strongly affected microbial community stability, although this phenomenon was not true in water. Furthermore, the specific microbial phyla and genes involved in the nitrogen cycle changed significantly following sediment-to-soil conversion, with the major nitrogen cycling processes altering from denitrification and dissimilatory nitrate reduction to ammonium to nitrification and assimilatory nitrate reduction to ammonia. Moreover, a compensation mechanism was observed in the functional genes related to the nitrogen cycle, such that all the processes in the nitrogen cycle were maintained following sediment-to-soil conversion. The oxidation-reduction potential strongly affected network complexity, microbial stability, and nitrogen cycling in the sediment and soil. These results aid in the understanding of responses of microorganisms to climate change and extreme drought. Our findings have considerable implications for predicting the ecological consequences of habitat conversion and for ecosystem management.

Distribution, sources, and potential health risks of fluoride, total iodine, and nitrate in rural drinking water sources of North and East China.

Small-scale water sources serving villages and towns are the main source of drinking water in rural areas. Compared to centralized water sources, rural water sources are less frequently monitored for water quality and have poor post-treatment facilities, making them vulnerable to drinking health risks. To reveal the hydrochemical characteristics, contaminant sources, and health risks in rural water sources, 189 water samples were collected from lakes and reservoirs, rivers, and groundwater in North and East China for major ions, nutrient salts, microelements, and stable isotope analysis. Statistical analysis and isotopic tracing were performed, as well as human health risk assessment. The exceeding threshold rates for fluoride (F-) and nitrate (NO3-) in surface water were 1.8 % and 9.1 %, respectively. For groundwater, the exceeding threshold rates were 20.9 % for F-, 15.7 % for total iodine (TI), and 4.5 % for NO3-. F- and TI were mainly derived from the leaching of fluoride- and iodine-containing minerals by cationic exchange, and NO3- is mainly derived from nitrogen in the soil (31.7-43.9 %), the use of ammonia fertilizers (24.3-36.1 %), and the discharge of manure and sewage (19.4-31.9 %). Nitrogen in the soil can be an important source of nitrate in the aquatic environment, and soils with higher clay content have a greater retention effect on the migration of nitrogen pollutants from the surface to the groundwater. F- in water sources contributes most to human health risks for drinking, followed by NO3- and TI, and a higher proportion of groundwater (37 %) present health risks for drinking than surface water (14 %) for children. Authorities should give high priority to optimizing the choice of water sources and technology for water treatment, and rational measures should be taken to protect water sources from the threats of anthropogenic pollution.

Effect of acupuncture in the acute phase of intracerebral hemorrhage on the prognosis and serum BDNF: a randomized controlled trial.

Background: Intracerebral hemorrhage (ICH) is a common cerebrovascular disease, with a high rate of disability. In the literature on Chinese traditional medicine, there is increasing evidence that acupuncture can help hematoma absorption and improve neurological deficits after cerebral hemorrhage. Brain-derived neurotrophic factor (BDNF), one of the most studied neurotrophic factors, is involved in a variety of neurological functions and plays an important role in brain injury recovery. We investigated the effect of acupuncture intervention in the acute phase of ICH on the prognosis and serum BDNF levels of several patient groups. Objective: To investigate the influence of acupuncture on the prognosis and brain-derived neurotrophic factor (BDNF) levels in patients in the acute phase of ICH. Methods: From November 2021 to May 2022, 109 subjects were consecutively enrolled, including patients with ICH, who were randomized into the acupuncture group (AG) and sham acupuncture group (SAG), and a control group (CG). The CG received the same acupuncture intervention as the AG, and the SAG received sham acupuncture, with 14 interventions in each group. The level of consciousness of patients with ICH was assessed and serum BDNF levels were measured in all three groups before the intervention and at 3 weeks after onset, and the level of consciousness and outcomes were assessed at 12 weeks after onset. Results: After the intervention, the level of consciousness of the AG improved significantly (P < 0.05); the BDNF level of only the AG increased significantly (P < 0.05); the changes in Glasgow Coma Scale (GCS) score and BDNF level were significantly greater in the AG than in the SAG (P < 0.05), especially for locomotion (P < 0.05). At 12 weeks post-onset, the AG showed better outcomes and recovery of consciousness than the SAG (P < 0.05).

Identification of nitrate sources of groundwater and rivers in complex urban environments based on isotopic and hydro-chemical evidence.

Groundwater and rivers in Chinese cities suffer from severe nitrate pollution. The accurate identification of nitrate sources throughout aquatic systems is key to the water nitrate pollution management. This study investigated nitrogen components of groundwater for twelve years and analyzed the sources of nitrate in the aquatic system based on dual isotopes (δ15N-NO3- and δ18O-NO3-) in the city of Nanjing, a core city of the Yangtze River Delta region, China. Our results showed that the ratio of nitrate to the sum of ammonia and nitrate in groundwater show an increasing trend during 2010-2021. The nitrate concentration was positively correlated with the proportion of cultivated land and negatively correlated with the proportion of forest land in the buffer zone. The relationship between Cl- and NO3-/ Cl- showed that agriculture and sewage sources increased during 2010-2015, sewage sources increased during 2016-2018, agriculture sources increased during 2019-2021. Manure and sewage were the primary sources of groundwater nitrate (72 %). There was no significant difference between the developed land (78 %), cultivated land (69 %), and aquaculture area (72 %). This indicates that dense population and intensive aquaculture in the suburbs have a significant impact on nitrate pollution. The contributions of manure and sewage to the fluvial nitrate sources in the lower reaches of the Qinhuai River Basin were 61 %. The non-point sources, including groundwater N (39 %) and soil N (35 %), were 74 % over the upper reaches. This study highlights the necessity of developing different N pollution management strategies for different parts of highly urbanized watersheds and considers groundwater restoration and soil nitrogen management as momentous, long-term tasks.

Dam construction reshapes sedimentary pollutant distribution along the Yangtze river by regulating sediment composition.

Dam construction has far-reaching impacts on pollutant accumulation and the pollutant-induced quality of aquatic environments. Nonetheless, its large-scale effects on pollutant distribution in sediments, which greatly contribute to the environmental impacts of coexisting pollutants, remain poorly understood. We collected sediments from the Yangtze River during the dry and normal seasons (with 'normal' defined in terms of precipitation level), and examined how dam construction alters the spatial trajectories of both inorganic and organic pollutants in the sediments. Sediment composition exhibited linear variation from the upper to the lower reaches, with clay and silt particles dominating the sediment in the Three Gorges Reservoir and sand particles dominating in the middle-lower reaches. Accordingly, upstream of the Three Gorges Dam (TGD), sedimentary carbon, nitrogen, phosphorus, heavy metal, polycyclic aromatic hydrocarbons (PAHs), and oxygenated PAHs (OPAHs) contents increased toward the TGD owing to its regulation of the spatial variation in sediment particle size. The TGD caused upstream sedimentary accumulation of pollutants to be higher nearer to the TGD than in the upper reaches by 17%-129% for carbon, nitrogen, and phosphorus, 7%-51% for heavy metals, 30% for PAHs, and 140% for OPAHs. Pollutant content was sharply lower below the TGD, by 0.58-11.15 times for carbon, nitrogen, and phosphorus, 0.1-2.6 times for heavy metals, 1.7 times for PAHs, and 5.6 times for OPAHs. Upstream of the TGD, levels of NH4+-N, the main form of N in the interstitial water of the Yangtze River, increased lineary toward the TGD, whereas those of NO3--N and NO2--N decreased. Sedimentary organic matter source contributions were consistent along the Yangtze River, being on an average 46% for C3 plants and 28% for soil organic substances, further confirming the dam's regulatory effect on pollutants. These findings provide a foundation for future assessments of the environmental impact of dam-induced river fragmentation and hydrological alterations, and for developing advanced watershed pollutant management strategies.

Elevated plasma intestinal fatty acid binding protein and aberrant lipid metabolism predict post-stroke depression.

Post-stroke depression (PSD) is the most common mood disorder caused by stroke. Stroke might bring about increased intestinal permeability accompanied by gut microbiota changes. According to the "gut-brain" axis hypothesis, increased intestinal permeability may contribute to PSD. Therefore, we investigated the association between increased intestinal permeability and the occurrence of PSD. Intestinal fatty acid binding protein (iFABP) is responsible for intestinal fatty acid absorption and transport and is often considered a biomarker of gut hyperpermeability, also known as leaky gut. We enrolled 48 healthy controls (HCs), 48 stroke patients without depression, and 48 PSD patients in this study. Plasma iFABP was measured in the three groups. CRP, LBP, and sCD14 were quantified for bacterial infection assessment. In addition, clinical laboratory indicators of lipid metabolism were assessed. The PSD patients exhibited higher iFABP levels compared with HCs and non-depressed stroke patients. Using OPLS discriminant analysis, four proteins (ApoA1, HDL-C, iFABP, and Lp(a)) were identified as potential biomarkers for distinguishing PSD patients from non-depression stroke patients. Our study discovered that elevated plasma iFABP levels in PSD patients correlated with the degree of depression, along with disturbed lipid metabolism. These findings also suggested the need to consider the role of a leaky gut in depression after stroke.

High oxidation state enabled by plated Ni-P achieves superior electrocatalytic performance for 5-hydroxymethylfurfural oxidation reaction.

Electrochemical 5-hydroxymethylfurfural oxidation reaction (HMFOR), as a clean biorefinery process, promotes a circular economy with value-added products. In HMFOR, the intrinsic catalytic activity and charge transfer mechanisms are crucial. Herein, nickel, co-deposited with phosphorus (Ni-P), attains superior electrocatalytic performance compared with Ni and its oxyhydroxides for the HMFOR. Such electrocatalytic activity of the Ni-P catalyst is attributed to the high oxidation state of surface Ni species, supported by the bulk Ni-P component. An unprecedented charge storing capacity enabled by the bulk Ni-P material maintains the spontaneous reaction between HMF and Ni3+ species to achieve a current density of 10 mA/cm2 normalized by the electrochemical active surface area at a low potential of 1.42 V vs RHE, reaching a 97% Faradaic efficiency toward 2,5-furandicarboxylic acid. This work, for the first time, sheds light on the importance of the electrode bulk material by showcasing the HMFOR via the Ni-P catalyst incorporating a charge-holding bulk component.

Determining nitrate sources in storm runoff in complex urban environments based on nitrogen and oxygen isotopes.

Urban storm runoff, as the primary transport medium for nutrients entering urban rivers, contributes to urban water contamination. Accurate source identification is critical for controlling water pollution. Although some studies have used nitrate isotopic composition (δ15N-NO3- and δ18O-NO3-) to identify nitrate (NO3--N) in urban storm runoff, the relatively low frequency of collecting samples in surface runoff within a single functional area hinders the understanding of spatial variations and dynamic process of NO3--N sources over the runoff process. This study investigated the nitrogen (N) concentrations and analyzed dynamic changes of NO3--N sources in surface runoff in different urban functional areas, drainage pipeline runoff, and channels during the complete runoff process in Wuxi, east China. The results showed that N concentrations in pipeline runoff and channels were higher than those in surface runoff, indicating that high concentration of N pollutants were accumulated in drainage pipelines. Information of δ15N-NO3- and δ18O-NO3- suggested that the main NO3--N source varied between runoff stages. NO3--N contribution from atmospheric deposition decreased in the order: surface runoff (57%) > residential pipeline runoff (25%) > channels (14%), while the opposite trend was observed for the contributions from sewage, increasing from 10%, 26% to 39%. In urban storm runoff, more sewage, fertilizers, and soil N were carried into the surface runoff after 30% of cumulative runoff ratio and carried into pipeline runoff in the initial 25% of cumulative runoff ratio in the residential area. As the first attempt to identify nitrate sources over the cumulative runoff in different urban functional areas, this work expands our understanding of the primary nitrate source in urban storm runoff. The findings provide important insights for developing strategies to mitigate non-point source water pollution.

Extracorporeal Shockwave Therapy as an Adjunctive Therapy for Frozen Shoulder: A Systematic Review and Meta-analysis.

BACKGROUND: The best nonsurgical treatment for frozen shoulder is still unclear. Extracorporeal shockwave therapy (ESWT) is an innovative adjunctive treatment for frozen shoulder, but its effect is still unclear. PURPOSE: To evaluate the published literature regarding the potential of ESWT as an adjunctive therapy for frozen shoulder. STUDY DESIGN: Systematic review; Level of evidence, 1. METHODS: Searches were conducted in the PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), and VIP Information databases for relevant studies between inception and November 2020. Included were randomized controlled trials (RCTs) for frozen shoulder that compared ESWT with routine treatments to controls. There were no restrictions on the treatment period, type of ESWT, or severity of symptoms. At least 1 of the following outcome indices was assessed: visual analog scale (VAS) for pain, Constant-Murley score (CMS) for shoulder function assessment, or external rotation range of movement (ER ROM). RevMan 5.3 software was used to evaluate the bias and quality of the included studies. For continuous variables, the mean difference (MD) or standardized MD (SMD) with the 95% CI was extracted. For dichotomous data, event ratios and sample sizes were extracted. RESULTS: Overall, 20 studies were included. The ESWT used as an adjunct to other interventions had better outcomes compared with control groups regarding immediate and short-term analgesic effects (immediate: MD, -1.10 [95% CI, -1.27 to -0.92], P < .00001; short-term: MD, -0.72 [95% CI, -0.94 to -0.50], P < .00001) as well as immediate function (SMD, 1.54 [95% CI, 1.19 to 1.89], P < .00001], I 2 = 0%). There was significant heterogeneity between studies for long-term analgesia (MD, -0.90 [95% CI, -1.40 to -0.41], P < .00001, I 2 = 89%) and ER ROM (MD, 10.31 [95% CI, 3.46 to 17.17], P < .003, I 2 = 93%). CONCLUSION: ESWT seems to be beneficial to patients with frozen shoulder by alleviating pain and improving function. ESWT could be used as an adjunct therapy to routine treatments, although the quality of the included RCTs was hampered by significant heterogeneity regarding long-term analgesia and joint ROM.

[Water Pollution Characteristics and Source Apportionment in Rapid Urbanization Region of the Lower Yangtze River: Considering the Qinhuai River Catchment].

Clarifying the current situation of regional water pollutants and the relationship between pollutants and pollution sources is considered essential for managing the water environment. Water quality identification index (WQI), cluster analysis (CA), positive matrix factorization (PMF), and stable isotope analysis in R (SIAR) were employed to interpret a large and complex water quality data set of the Qinhuai River catchment generated during 2015 to 2019 to monitor of 11 parameters at 29 different sampling sites. WQI analysis indicated that water quality in Qinhuai River catchment is considered to have "moderate pollution," and an improving trend of water quality was observed at the interannual scale. TN was the most deteriorated of all pollution parameters. CA and PMF results on the spatial scale revealed that sampling sites located at downtown of Nanjing and Lishui District or Jangling University town were highly polluted due to the sewage from domestic sewage and business service sewage (28.88%) as well as industrial wastewater (27.43%), while sampling sites located at Hushu Street Administrative District, Ergan River, and Sangan River were slightly polluted by rural domestic wastewater and garbage (28.79%), and agricultural non-point source pollution (24.3%). The middle-lower reaches (Jiangning Development Zone and Moling Street) and middle reaches (Lukou Street Administrative District) were moderately polluted by industrial wastewater (27.25%), sewage from domestic wastewater and business service wastewater (31.62%) as well as inner sources (24.76%). The SIAR results showed that NO3--N was the main nitrogen form, and the NO3--N mainly originated from sewage (61%) and soil (34%) in the Yuntaishan River sub-catchment. These results will aid in the development of measures required to control water pollution in river catchments.

Body Composition as a Predictor of Toxicity and Prognosis in Patients with Diffuse Large B-Cell Lymphoma Receiving R-CHOP Immunochemotherapy.

BACKGROUND: Our study measured the body composition of Diffuse large B-cell lymphoma (DLBCL) patients receiving rituximab with cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) regimen by computed tomographic (CT) and assessed their correlation with treatment-related toxicity and other adverse outcomes. METHODS: We retrospectively analyzed 201 DLBCL patients who underwent pre-treatment abdominal CT examination. CT images were used to assess body composition metrics at the third lumbar vertebrae including fat tissues and muscle. Based on the skeletal muscle area (SMA) and density (SMD), skeletal muscle index (SMI), skeletal muscle gauge (SMG = SMI × SMD) and lean body mass (LBM) were calculated. Also analyzed were the toxicity, adverse events and survival. RESULTS: We found that SMG, SMD, SMI and LBM were correlated with any grade 3-4 toxicity, dose reduction, hospitalization or termination of the treatment due to immunochemotherapy and worse survival. However, multivariate analysis demonstrated SMG [progression-free survival (PFS): hazard ratio (HR), 2.889; 95% CI, 1.401-5.959; p = 0.004; overall survival (OS): HR, 2.655; 95% CI, 1.218-5.787; p = 0.014] was the best predictor of poor prognosis. CONCLUSIONS: SMG, SMD, SMI and LBM were identified as predictors of adverse reactions and poor survival. SMG was an innovative and valuable indicator of immunochemotherapy toxicity and other adverse outcomes. Additionally, it can be used to individualize antineoplastic drug dosing.

The clinical implication of soluble PD-L1 (sPD-L1) in patients with breast cancer and its biological function in regulating the function of T lymphocyte.

This work investigated the clinical prognostic implications and biological function of plasma soluble programmed cell death ligand 1 in breast cancer patients. Plasma sPD-L1 levels of recurrent/metastatic breast cancer patients were determined, and the association of sPD-L1 levels and metastatic progression-free survival and metastatic overall survival was assessed. The PD-L1 expression on breast cancer cells was analyzed by flow cytometry, and the level of sPD-L1 in the supernatant of breast cancer cells was determined by enzyme-linked immunosorbent assay. Furthermore, the effect of sPD-L1 on the proliferation and apoptosis of T lymphocytes was detected by WST-1 assay and flow cytometry. The plasma sPD-L1 levels in 208 patients with recurrent/metastatic breast cancer before receiving first-line rescue therapy were measured. The optimal cutoff value of plasma sPD-L1 for predicting disease progression was 8.774 ng/ml. Univariate and multivariate analyses identified high sPD-L1 level (≥ 8.774 ng/ml) and visceral metastasis were independent factors associated with poor prognosis. Relevance analysis showed that the plasma sPD-L1 level was weaklyassociated with some systemic inflammation markers, including white cell count (WBC), absolute monocytecount, and absolute neutrophil count. Furthermore, we found sPD-L1 could be found in supernatant of culture with breast cancer cell line expressing PD-L1 on the cell surface and inhibit T lymphocyte function, playing a negative regulatory role in cellular immunity. sPD-L1 was a good tumor predictive maker in breast cancer and it may play a potentially important role in immune tolerance.

Quantitative identification of non-point sources of nitrate in urban channels based on dense in-situ samplings and nitrate isotope composition.

Quantitative identification of non-point sources of nitrate in urban channels plays a critical role in effective nutrient management in urban regions. This is an emerging issue due to fast urbanization and the resultant complicated hydrological and hydraulic conditions in urban areas. In this study, we examine spatial-temporal characteristics of nitrogen concentration in urban channels based on dense in-situ samplings during a one-year period over a small urban catchment in China. We quantitatively identify nitrate sources into urban channels based on dual-isotope analyses and Bayesian isotope mixing model. Results show that nitrogen concentration peaks in winter as well as in urban channels and land surfaces in the urban core region. Sewage (47%) is the dominate contributor to NO3--N in urban channels, followed by NH4+ in fertilizer (30%) as the second contributor. Sewage (NH4+ in fertilizer) contributes more NO3--N to channels in winter (summer) with the proportion of 65% (44%), and more NO3--N to urban core (suburban) channels with the proportion of 59% (42%). The rainfall and distribution of rainwater drains explain the monthly and spatial variations of contribution of NO3--N sources well, respectively. In addition, less NO3--N in the urban channels derives from nitrification, which is consistent with the results of high properties of NH4+-N/TN in this region. Our results highlight the key roles of land use types and rainfall in NO3--N source apportionment, and provide support for the nitrogen management practices in urbanized regions.

Memantine, Donepezil, or Combination Therapy-What is the best therapy for Alzheimer's Disease? A Network Meta-Analysis.

INTRODUCTION: Alzheimer's disease (AD) is a degenerative brain disease that progresses over time, heavily burdening patients, families, and aging societies worldwide. Memantine and donepezil are frequently used in its treatment, both as monotherapy and in combination. This multiple treatment comparison meta-analysis assessed the efficacy of these regimens and placebo in the management of AD. METHODS: We searched PubMed, Embase, the Cochrane Library, and Wanfang Med Online and China National Knowledge Infrastructure for English and Chinese publications from the first records to 17 April 2020. Two investigators scanned articles for placebo-controlled trials of memantine and donepezil alone and in combination. We extracted data on the following outcomes: cognition, global assessment, daily activities, neuropsychiatric symptoms, adverse events, and the acceptability and cost of these treatment regimens. RESULTS: Of 936 records screened, we included 54 trials in this analysis. The combination therapy was more effective in improving cognition (mean difference (MD)-5.01, 95% credible interval (95% Crl) -10.73 to 0.86 in the Alzheimer's Disease Assessment Scale-Cognitive Subscale; MD 9.61, 95% Crl 2.29 to 16.97 in the Severe Impairment Battery), global assessment (MD -2.88, 95% Crl -6.04 to 0.40), daily activities (MD 13.06, 95% Crl -34.04 to 58.92), and neuropsychiatric symptoms (MD -6.84, 95% Crl -10.62 to -2.82) compared with placebo. Memantine was more acceptable than placebo (MD 0.93, 95% Crl 0.69 to 1.22). CONCLUSIONS: Memantine plus donepezil showed superior outcomes for cognition, global assessment, daily activities, and neuropsychiatric symptoms, but lower acceptability than monotherapy and placebo. Combination therapy may be more cost-effective, because memantine slows the progression of AD.

Spatial-temporal characteristics of nitrogen degradation in typical Rivers of Taihu Lake Basin, China.

In this study, we focus on the measurement of different nitrogen (N) forms and investigate the spatial-temporal variability of degradation coefficient in river channels. We aim to provide a new approach of deriving in-situ degradation coefficients of different N forms, and highlight factors that determine the spatial-temporal variability of degradation coefficients. Our results are based on a two-year field survey in 34 channels around the Taihu Lake Basin, eastern China. The derived degradation coefficients of different N forms based our newly-developed experimental device are: degradation coefficients of TN, NH4+-N and NO3-N range from 0.006-0.449 d-1, 0.022-1.175 d-1 and -0.096-2.402 d-1, respectively. The degradation coefficients of N show strong dependence on N concentration and water temperature. The seasonal difference of water temperature and N concentration leads to spatial-temporal variability of degradation coefficients. The derived degradation coefficients of N are further verified through one-dimensional water quality model simulations. The degradation coefficient obtained in this study and the influencing factors of its spatial-temporal variability provide invaluable reference for studies in aquatic environment.

Spatio-Temporal Differences in Nitrogen Reduction Rates under Biotic and Abiotic Processes in River Water of the Taihu Basin, China.

Understanding spatio-temporal differences in nitrogen (N) transformation, transport and reduction rates in water bodies is critical to achieve effective mitigation of river eutrophication. We performed culture experiments in six rivers in the Taihu Basin using a custom made in-situ experimental apparatus. We investigated spatio-temporal differences in reduce processes and rates of different N forms and assessed the contribution of biological processes to dissolved inorganic N (DIN) reduce. Results showed that biological processes played a major role in N reduction in summer, while non-microbial processes were dominant in winter. We observed significant spatial and temporal differences in the studied mechanisms, with reduction rates of different N compounds being significantly higher in summer and autumn than spring and winter. Reduction rates ranged from 105.4 ± 25.3 to 1458.8 ± 98.4 mg·(m³·d)-1 for total N, 33.1 ± 12.3 to 440.9 ± 33.1 mg·(m³·d)-1 for ammonium, 56.3 ± 22.7 to 332.1 ± 61.9 mg·(m³·d)-1 for nitrate and 0.4 ± 0.3 to 31.8 ± 9.0 mg·(m³·d)-1 for nitrite across four seasons. Mean DIN reduction rates with and without microbial activity were 96.0 ± 46.4 mg·(m³·d)-1 and 288.1 ± 67.8 mg·(m³·d)-1, respectively, with microbial activity rates accounting for 29.7% of the DIN load and 2.2% of the N load. Results of correlation and principal component analysis showed that the main factors influencing N processing were the concentrations of different N forms and multiple environmental factors in spring, N concentrations, DO and pH in summer, N concentrations and water velocity in autumn and N concentrations in winter.