[Assessment of Critical Loads of Nitrogen Deposition in Natural Ecosystems of China].

Excessive nitrogen (N) deposition causes a series of environmental problems, including biodiversity loss. Therefore, assessing current N deposition thresholds of natural ecosystems is critical for regional N management and pollution control. In this study, the critical loads of N deposition in mainland China were estimated using the steady-state mass balance method, and the spatial distribution of ecosystems that exceeded the critical load was evaluated. The results showed that areas with critical loads of N deposition higher than 56, in the range of 14-56, and lower than 14 kg·(hm2·a)-1 accounted for 6%, 67%, and 27% of that in China, respectively. The areas with higher critical loads of N deposition were mainly distributed in the eastern Tibetan Plateau, northeastern Inner Mongolia, and parts of south China. Lower critical loads of N deposition were mainly distributed in the western Tibetan Plateau, northwest China, and parts of southeast China. Moreover, the areas where N deposition exceeded the critical loads accounted for 21% of that in mainland China, being mainly distributed in southeast and northeast China. The exceedances of critical loads of N deposition in northeast China, northwest China, and the Qinghai-Tibet Plateau were generally lower than 14 kg·(hm2·a)-1. Therefore, the management and control of N in these areas that exceeded the critical load of deposition is more worthy of future attention.

[Runoff Simulation and Its Response to Extreme Precipitation in the Yangtze River Basin].

Studies on runoff are crucial for the scientific allocation, utilization, and development of water resources and can provide an important basis for the prevention and control of flood and drought disaster, as well as water environmental pollution management. Affected by global warming, the frequency and intensity of extreme climate events, particularly extreme precipitation, have significantly changed in recent years, which can directly or indirectly impact runoff changes. In this study, we used the SWAT model to simulate the spatiotemporal variations in runoff in the Yangtze River Basin from 1965 to 2019 and analyzed the response of runoff to precipitation under extreme conditions. The results showed that the changes in total runoff in the Yangtze River Basin were not significantly different from 1965 to 2019. The total runoff and the mid-lower runoff in the basin experienced four stages of "dry-wet-dry-wet." Simulations revealed that under the 50-year extreme precipitation event, the increase in daily average runoff was 6200%, 21%, and 15% for the typical sub-basins of the upper, middle, and lower reaches of the Yangtze River, respectively. Additionally, the increase in monthly and annual average runoff was 355%, 5%, and 1.3% and 78%, 1%, and 0.24%, for upper, middle, and lower reaches of the Yangtze River, respectively. Moreover, under the 100-year extreme precipitation, the average daily runoff increasing rates were 8000%, 25%, and 17% for upper, middle, and lower reaches of the Yangtze River, respectively, compared to the monthly increase of 437%, 7%, and 1.5% and annual increase of 96%, 1.2%, and 0.28%, respectively. Our findings may improve the understanding of hydrological responses to climate change and provide valuable inferences to decision-makers and water managers for better allocation and management of water resources.

A false positive serology test of SARS­CoV­2 in a patient with Waldenström's macroglobulinemia: A case report.

The serology test of SARS-CoV-2 is one of the critical assays to make a diagnosis of SARS-CoV-2 infection. The gold immunochromatography assay (GICA) is a common measure to test SARS-CoV-2 specific IgG and IgM. The sensitivity and specificity of the assay are ~>80%. It has been reported that the result of GICA could be compromised in various situations, such as auto-immune diseases, Kawasaki disease, pregnancy or other conditions. However, following the European Hematology Association's consensus statement on the management of Waldenström's Macroglobulinemia (WM) patients, serological tests for SARS-CoV-2 specific IgM should not be affected by the total IgM or paraprotein levels. The present study reports a patient with duplicate positive serology tests of SARS-CoV-2 which is hypothesized to be due to monoclonal IgM caused by WM.

[Denitrification Loss and N2O Emission from Different Carbon Inputs in Orchard Drains Sediments].

The orchard is an important economic crop in Taihu Lake region. Heavy nitrogen application in orchard results in great nitrogen loss to drainage ditch, and unbalanced carbon nitrogen ratio. Therefore, carbon might be an important limiting factor for sediment nitrification and denitrification. A soil incubation experiment controlled by the acetylene inhibition method was conducted under laboratory conditions to study the denitrification loss and N2O emissions of orchard drainage ditch soil. We designed five carbon input levels of 0, 5, 25, 50 and 100 mg·L-1, which were noted as C0, C1, C2, C3 and C4, respectively, meanwhile there was 5 mg·L-1 net nitrogen input in the form of KNO3 in each treatment. The results showed that carbon inputs could stimulate both denitrification rates (DN) and N2O emission rates. Carbon and nitrogen ratio had a significant effect on N2O emission rates and denitrification loss rates (P<0.05). When the carbon and nitrogen ratio was 10:1, total cumulative denitrification losses and N2O emissions were both highest (319.26 µg·kg-1 and 6.20 µg·kg-1, respectively) among the treatments, which accounted for 1.28% and 0.02% of net nitrogen input, respectively. This result indicated that the carbon and nitrogen ratio of 10:1 was most favorable for N2O emissions and denitrification process in sediments.

[Temporal and spatial variations of total nitrogen and total phosphorus in the typical reaches of Qinhuai River].

The year-round concentrations of total nitrogen (TN) and total phosphorus (TP) were monitored from June 2010 to May 2011 in the typical reaches of the Qinhuai River. The spatial and temporal variations in TN and TP concentrations and the pollution status of the river water were investigated using typical statistics analysis. Results showed that the river water was seriously polluted in terms of TN and TP, and that the concentrations of both TN and TP showed high spatial and temporal variations. The average TN concentrations of the river water in the traditionally managed agricultural area, intensively managed agricultural area, and urban area were 1.80, 3.97 and 9.25 mg L(-1), respectively; The corresponding average TP concentrations were 0.03, 0.11 and 0.50 mg L(-1), respectively, showing similar spatial patterns with those of TN. The spatial variations in TN and TP concentrations in river water indicated that the urban area and intensively managed agricultural area, rather than the traditionally managed agricultural area, were the major sources for TN and TP in the river water. The average TN concentrations of river water during the wet season and dry season were 1.89 and 4.58 mg x L(-1), respectively; and the corresponding average TP concentrations were 0.11 and 0.14 mg x L(-1), respectively. The temporal variations indicated that the pollution status of the river water was more serious during the dry season than that during the wet season. Assessment results of eutrophication indicated that the majority of Qinhuai River reaches were in the stage of eutrophication, thus deserving immediate controlling measures.

Alcohol abuse-related severe acute pancreatitis with rhabdomyolysis complications.

Non-traumatic rhabdomyolysis is a rare complication of acute pancreatitis. One of the major risk factors of both acute pancreatitis and rhabdomyolysis is alcohol abuse. However, only a few studies have reported the prognosis and association of severe acute pancreatitis (SAP) and rhabdomyolysis in alcohol abuse patients. In the present study, we report two cases presenting with SAP complicated by rhabdomyolysis following high-dose alcohol intake. The disease onset, clinical manifestations, laboratory data, diagnosis and treatment procedure of each patient were recorded, and the association with rhabdomyolysis was analyzed. Alcohol consumption was the most predominant cause of SAP and rhabdomyolysis in these patients. SAP-related rhabdomyolysis was primarily induced by the toxicity associated with pancreatic necrosis. The laboratory tests revealed that the concentration of serum creatine kinase (CK) and myoglobin increased and acute renal failure symptoms were present, which provided an exact diagnosis for SAP-induced rhabdomyolysis. Rhabdomyolysis and subsequent hypermyoglobinuria severely impaired kidney function and aggravated hypocalcemia. The therapy of early stage SAP complicated by rhabdomyolysis involved liquid resuscitation support. When first stage treatment fails, blood purification should be performed immediately. Both patients developed multiple organ failure (MOF) and succumbed to the disease. Considering the two cases presented, we conclude that alcohol-related SAP complicated by rhabdomyolysis may have a poor clinical prognosis.

[Statistical analysis of factors influencing N2O emission from paddy fields in Asia].

Most previous studies attributed variation in N2O emission from paddy fields to water managements and fertilizer input. In this study, we compiled a database of N2O emission from paddy fields in Asia, including water management, type and amount of nitrogen fertilizer, soil property, climate and rice types. After screening the influencing factors with statistical significance (p < 0.01) such as different water managements, N input, different organic N types, interaction of soil total nitrogen content and different pH levels, different annual temperature levels, and different rice types, a linear model was established to link N2O emission to those factors, which could totally explain up to 60.7% of the observed variation in N2O emission. The most important influencing factor was the amount of N fertilizer input, which had significantly positive correlation with N2O fluxes. Relative emission fluxes of continuous flooding, intermittent irrigation and wet irrigation were 0.17:0.56: 1. The soil total nitrogen content had significantly positive effect on N2O fluxes while the optimum pH for N2O emission was pH > 8. Straw of N-fixing crop had much higher fluxes than other organic fertilizers while manure had no significant effects on increasing N2O emission. Application of other crop straws actually reduced N2O emission by 36%, as compared with fields without organic N input. The relative fluxes for early rice and later rice were 71% and 48% of that for single rice, respectively. Inclusion of more influencing factors such as soil property, climate and rice type helped explaining more of the variations in the observed N2O emission from paddy fields.

[Effects of applying nitrogen fertilizer and fertilizer additive on rice yield and rice plant nitrogen uptake, translocation, and utilization].

A field experiment was conducted in the Taihu Lake region of southern Jiangsu to study the effects of applying nitrogen (N) fertilizer and fertilizer additive on the rice yield and the rice plant N uptake, translocation, and utilization. Applying N fertilizer had significant positive effects on the rice yield, accumulative absorbed N at all growth stages and at each growth stage, and N translocation rate after anthesis (P < 0.01). However, when the N application rate exceeded 200 kg x hm(-2), its yield-increasing effect was not significant (P > 0.05). The N translocation rate after anthesis and the N fertilizer use efficiency decreased with increasing N application rate. Applying fertilizer additive further improved the rice yield, accumulative absorbed N, N translocation rate after anthesis, and N fertilizer use efficiency, and this effect was more evident when the N application rate was equal to or greater than 200 kg x hm(-2). Relatively high rice yield and N use efficiency were achieved when applying 150 kg x hm(-2) of N fertilizer without the application of fertilizer additive.

[Effects of long-term fertilization on soil particulate organic carbon and nitrogen in a wheat-maize cropping system].

0-20 cm soil samples were collected from an 18-year wheat-maize rotation field on the North China Plain to study the effects of long-term fertilization on the contents and storages of soil particulate organic carbon (POC), particulate organic nitrogen (PON), incorporated organic carbon (IOC), and incorporated organic nitrogen (ION). The long-term fertilization experiment was designed to include 7 treatments, i.e., chemical NPK (NPK), organic manure (OM), 1/2 organic manure plus 1/2 chemical NPK (1/20 MN), chemical NP (NP), chemical PK (PK), chemical NK (NK), and control (CK). After 18 years experiment, all the fertilization treatments showed higher contents of soil POC, PON, IOC and ION, higher proportions of soil POC to soil total organic carbon (TOC) and of soil PON to soil total nitrogen (TON), and higher C/N ratio of soil particulate organic matter. The storages of soil POC and PON under fertilization treatments were increased by 11.7%-196.8% and 13.0%-152.2%, respectively, compared with the control. The contribution of soil POC to the increased storage of soil TOC ranged from 31.5% to 67.3%, and that of soil PON to the increased storage of soil TON ranged from 14.3% to 100.0%. The storages of soil IOC and ION under fertilization treatments increased by 2.0%-75.0% and 0.0%-69.8%, respectively, compared with the control. Among the fertilization treatments, treatment OM had the highest storages of soil POC, PON, IOC and ION, followed by treatment 1/20 MN, and the treatments of applying chemical fertilizers alone. Balanced application of chemical fertilizers (treatment NPK) showed higher storages of soil POC, PON, IOC and ION than imbalanced application (treatments NP, PK, and NK). It was suggested that applying organic manure or its combination with chemical NPK and the balanced application of chemical NPK could be the keys for the increase of soil POC, PON, IOC and ION contents and storages.