The shape of reactive nitrogen losses from intensive farmland in China.

Reactive nitrogen (Nr) pollution has changed radically accompanied by severe intensive farming. This pollution further contributes to ecological degradation and climate warming. Despite this recognition, little is known about the spatial pattern of various Nr loss from croplands and corresponding environmental costs. Here, we identified the major pathway of Nr loss based on provincial estimates in 2008 and 2018, and validated by synchronous observation of ammonia volatilization, N runoff and N leaching using historical literature synthesis. We also evaluated environmental costs at provincial scale and detected the influence factors that dominating the pollution swapping among different Nr forms. Our results show that the total Nr loss was 6.28 ± 1.81 and 5.56 ± 2.30 Tg N yr-1 for Chinese croplands in 2008 and 2018. Ammonia volatilization, which accounted for more than half of the total Nr at the national scale, was proven to be the major Nr loss for two-thirds of the provinces and 80 % of the field observations. The contribution of runoff, which is dominant by precipitation, soil clay content and CEC, was gradually smaller than that of leaching from southeast to northwest. Ammonia and nitrous oxide contributed of 59.3 % âˆ¼ 65.4 % of TNr but 80.9 % âˆ¼ 81.5 % of total environmental damage caused by Nr in China. The use of nitrification inhibitors and straw return indicated pollution swapping among various Nr forms. This study emphasizes that the future practices to reduce total Nr loss need to account for local environmental conditions and have pollution swapping in sights.

Quercetin inhibits caspase-1-dependent macrophage pyroptosis in experimental folic acid nephropathy.

BACKGROUND: The role of pyroptosis in kidney disease is limited and incomplete. Quercetin, a flavonoid compound present in a variety of fruits, vegetables, and plants, has shown antioxidant and anti-inflammatory properties. This study was designed to validate the importance of pyroptosis in an experimental model of folic acid nephropathy and to explore the effect of quercetin in protecting against pyroptosis. METHODS: Gene set enrichment analysis (GSEA) and weighted gene co-expression network analysis (WGCNA) were used to establish the correlation between pyroptosis and folic acid nephropathy. Immune cell infiltration, network pharmacology and single-cell RNA sequencing analysis were utilized to ascertain the specific target of quercetin in relation to pyroptosis. Finally, quercetin's role was verified in vivo and in vitro. RESULTS: The GSEA analysis revealed a significant correlation between pyroptosis and folic acid nephropathy (NES = 1.764, P = 0.004). The hub genes identified through WGCNA were closely associated with inflammation. Molecular docking demonstrated a strong binding affinity between quercetin and caspase-1, a protein known to be involved in macrophage function, as confirmed by immune cell infiltration and single-cell analysis. Quercetin demonstrated a significant amelioration of kidney injury and reduction in macrophage infiltration in the animal model. Furthermore, quercetin exhibited a significant inhibition of caspase-1 expression, subsequently leading to the inhibition of pro-inflammatory cytokines expression, such as IL-1ß, IL-18, TNF-α, and IL-6. The inhibitory effect of quercetin on macrophage pyroptosis was also confirmed in RAW264.7 cells. CONCLUSION: This study contributes substantial evidence to support the significant role of pyroptosis in the development of folic acid nephropathy, and highlights the ability of quercetin to downregulate caspase-1 in macrophages as a protective mechanism against pyroptosis.

Associations among carotid plaque progression, cerebrovascular/cardiovascular diseases and LDL-C/non-HDL-C goal achievement in diabetic patients: A retrospective cohort study.

BACKGROUND: Impaired glycolipid metabolism can induce vascular injury and plaque formation. It is important to investigate the associations between carotid plaque progression and lipid-lowering goal achievement and cardiovascular disease. METHODS: Diabetic patients who underwent at least 2 carotid ultrasound scans with intervals ≥0.5 years and were hospitalized in the Department of Endocrinology at Sun Yat-sen Memorial Hospital were included. Patients were divided into 3 groups based on carotid plaque progression: the persistent plaque absence, new-onset plaque and persistent plaque presence groups. The primary outcomes were CHD and stroke, while the secondary outcomes were low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) goal achievement. RESULTS: There were 304 diabetic patients included, with a median follow-up period of 2.15 years. In multivariable logistic regression analysis, persistent plaque presence was positively associated with a 2.285-fold increase in coronary heart disease (CHD) prevalence, while new-onset plaque was associated with a 3.225-fold increase in stroke prevalence compared to persistent plaque absence in patients with follow-up periods ≥ 0.5 years. The association remained significant in patients with a follow-up period ≥ 1 year and ≥2 years. The velocity of average plaque length change was independently associated with increased ΔLDL-C (last - goal) (ß = 0.073, P = 0.048). CONCLUSION: Carotid plaque progression had long-term association with CHD and stroke starting from 0.5 years, while the velocity of average plaque length associated with increased ΔLDL-C (last - goal) might reflect patient response to statins. Repeated carotid plaque measurements might guide lipid-lowering therapies.

Deceleration of Cropland-N2O Emissions in China and Future Mitigation Potentials.

Agricultural soils are the largest anthropogenic emission source of nitrous oxide (N2O). National agricultural policies have been implemented to increase crop yield and reduce nitrogen (N) losses to the environment. However, it is difficult to effectively quantify crop-specific and regional N2O mitigation priorities driven by policies, due to lack of long-term, high-resolution crop-specific activity data, and oversimplified models. Here, we quantify the spatiotemporal changes and key drivers of crop-specific cropland-N2O emissions from China between 1980 and 2017, and future N2O mitigation potentials, using a linear mixed-effect model and survey-based data set of agricultural management measures. Cropland-N2O emissions from China tripled from 102.5 to 315.0 Gg N yr-1 between 1980 and 2017, and decelerated since 1998 mainly driven by country-wide deceleration and decrease in N rate and the changes in sowing structure. About 63% of N2O emissions could be reduced in 2050, primarily in the North China Plain and Northeast China Plain; 83% of which is from the production of maize (33%), vegetables (27%), and fruits (23%). The deceleration of N2O emissions highlights that policy interventions and agronomy practices (i.e., optimizing N rate and sowing structure) are potential pathways for further ambitious N2O mitigation in China and other developing countries.

Decoupling between ammonia emission and crop production in China due to policy interventions.

Cropland ammonia (NH3 ) emission is a critical driver triggering haze pollution. Many agricultural policies were enforced in past four decades to improve nitrogen (N) use efficiency while maintaining crop yield. Inadvertent reductions of NH3 emissions, which may be induced by such policies, are not well evaluated. Here, we quantify the China's cropland-NH3 emission change from 1980 to 2050 and its response to policy interventions, using a data-driven model and a survey-based dataset of the fertilization scheme. Cropland-NH3 emission in China doubled from 1.93 to 4.02 Tg NH3 -N in period 1980-1996, and then decreased to 3.50 Tg NH3 -N in 2017. The prevalence of four agricultural policies may avoid ~3.0 Tg NH3 -N in 2017, mainly located in highly fertilized areas. Optimization of fertilizer management and food consumption could mitigate three-quarters of NH3 emission in 2050 and lower NH3 emission intensity (emission divided by crop production) close to the European Union and the United States. Our findings provide an evidence on the decoupling of cropland-NH3 from crop production in China and suggest the need to achieve cropland-NH3  mitigation while sustaining crop yields in other developing economies.

Nitrogen and phosphorus trajectories (1998-2030) under regional development strategy of mainland China.

A good understanding of the nutrient cycle under a regional development strategy is crucial for nutrient management decision-making. Quantitatively assessment of nutrient flow under the regional coordinated development strategy in mainland China can provide scientific reference for achieving global high-quality coordinated economic and agricultural development. In this study, the characteristics of nitrogen (N) and phosphorus (P) flows of agricultural systems in mainland China from 1998 to 2030 were quantified using nutrient flows in food chain environment and resource (NUFER) model. The results revealed that national N and P surplus intensity were 50.3 and 18.6 kg·hm-2 in 2018, respectively, and there is still space for soil nutrient retention. The national input and output of N and P showed a continuous upward trend over the last two decades. Chemical fertilizer application and livestock rearing are the key points for nutrient management in China's agricultural systems. Under the regional development strategy, considerable geographical variation in N and P surplus intensity was observed across the country. From 1998 to 2013, the regional distribution of N and P surplus intensity was in accordance with regional economic characteristics. Areas with higher N and P surplus intensities were mainly in the eastern and central regions. From 2014 to 2018, equal emphasis on ecology and economy in the Yangtze River Economic Belt allowed development without aggravating the deterioration of the N and P surplus in the region. Over the next 10 years, our simulation predicts that future nutrient footprints tend to decrease, and coordinated governance of regional development and agricultural environment protection are the key to regional sustainable development.

Characteristics and drivers of daily nitrogen and phosphorus losses from rice-rapeseed rotation systems in the middle reaches of the Yangtze River.

Crop production systems involving the use of high rates of fertilizer application caused significant losses of nitrogen (N) and phosphorus (P) to the environment, resulting in air pollution and water body eutrophication. Quantitating N and P losses and its drivers in crop production systems was critical for optimizing water and fertilizer management measures to mitigate the nutrient losses. However, N and P losses estimation remains highly uncertain in the field at event scale. We here quantify daily N and P losses and its drivers (daily N and P water input, N and P uptake, N and P water surplus, water loss, etc.) in rice-rapeseed growing systems by high-frequency field experiments at event scale in Central China. Results revealed that there were significant trade-off relationships between daily uptake and surplus for N and P during the whole growing stages both for rice and rapeseed. Although it was not significantly related in heading to mature stage for rapeseed, synergies between daily input or surplus and loss were found for N. Redundancy analysis revealed that water input and leaching loss contributed most for N and P loss in rice and rapeseed. The nutrient losses in easier stages should be reduced by postponing the base fertilizer and making it in line with the crop uptake. The study enhanced our knowledge of N and P losses mechanism for crop production systems and provided a scientific basis for optimization of water and fertilizer managements and N and P loss estimation models.

Biogas slurry application could potentially reduce N2O emissions and increase crop yield.

The huge excrement quantity from the increasing large-scale livestock stressed the ecological, environmental deterioration. As a major benefit for handling livestock manure, the slurry of biogas (BS) is developed during the production of biogas that might increase plant productivity. However, nitrous oxide (N2O) emissions from BS are considered a significant danger to the environment due to global warming potential. Furthermore, applying different proportions of BS combined with chemical fertilizer (CF) on N2O productions in the North China Plain (NCP) remains unclear. Herein, two sequential field trials were performed by maize-wheat rotations to substitute the CF by BS and reduce N2O emissions while keeping the crop yield stable. Four treatments were conducted, including T1, T3, T6, and CK. A total of 226.5 kg N ha-1 used in the maize-wheat rotation system. Additionally, different ratios of BS (100%, 80%, and 50%) combined with CF were used in wheat season in the tillering stage. Results showed integrated applications of BS with CF have potential for reducing N2O emission. Our findings showed that the maximum grain yield of CF was 6250 kg ha-1, which might be achieved by applying 38% BS and 62% of CF. This ratio yielded 1.03 kg ha-1 N2O emissions, which was 15% lesser than the N2O emission of CK, 1.21 kg ha-1. Considering whole growing period of wheat biogas treatments significantly reduced the cumulative N2O emissions from 17% to 26% compared to CF. To achieve maximum yield and minimum N2O emissions, an optimum 38% BS ratio has been suggested. The integrated use of BS and CF provided the greatest grain yield because of necessary nutrients provided by both slurry and CF. Consequently, N2O emissions reduced based on frequency and type of fertilizer. In conclusion, 38% ratio of BS combined with 62% CF would be a suitable approach to mitigate N2O emission and simultaneously increase crop yield in NCP.

Improved Estimates of Ammonia Emissions from Global Croplands.

Reducing ammonia (NH3) volatilization from croplands while satisfying the food demand is strategically required to mitigate haze pollution. However, the global pattern of NH3 volatilization remains uncertain, primarily because of the episodic nature of NH3 volatilization rates and the high variation of fertilization practices. Here, we improve a global estimate of crop-specific NH3 emissions at a high spatial resolution using an updated data-driven model with a survey-based dataset of the fertilization scheme. Our estimate of the globally averaged volatilization rate (12.6% ± 2.1%) is in line with previous data-driven studies (13.7 ± 3.1%) but results in one-quarter lower emissions than process-based models (16.5 ± 3.1%). The associated global emissions are estimated at 14.4 ± 2.3 Tg N, with more than 50% of the total stemming from three stable crops or 12.2% of global harvested areas. Nearly three-quarters of global cropland-NH3 emissions could be reduced by improving fertilization schemes (right rate, right type, and right placement). A small proportion (20%) of global harvested areas, primarily located in China, India, and Pakistan, accounts for 64% of abatement potentials. Our findings provide a critical reference guide for the future abatement strategy design when considering locations and crop types.

Global mapping of crop-specific emission factors highlights hotspots of nitrous oxide mitigation.

Mitigating soil nitrous oxide (N2O) emissions is essential for staying below a 2 °C warming threshold. However, accurate assessments of mitigation potential are limited by uncertainty and variability in direct emission factors (EFs). To assess where and why EFs differ, we created high-resolution maps of crop-specific EFs based on 1,507 georeferenced field observations. Here, using a data-driven approach, we show that EFs vary by two orders of magnitude over space. At global and regional scales, such variation is primarily driven by climatic and edaphic factors rather than the well-recognized management practices. Combining spatially explicit EFs with N surplus information, we conclude that global mitigation potential without compromising crop production is 30% (95% confidence interval, 17-53%) of direct soil emissions of N2O, equivalent to the entire direct soil emissions of China and the United States combined. Two-thirds (65%) of the mitigation potential could be achieved on one-fifth of the global harvested area, mainly located in humid subtropical climates and across gleysols and acrisols. These findings highlight the value of a targeted policy approach on global hotspots that could deliver large N2O mitigation as well as environmental and food co-benefits.

Improved Jayaweera-Mikkelsen model to quantify ammonia volatilization from rice paddy fields in China.

Current estimates of China's ammonia (NH3) volatilization from paddy rice differ by more than twofold, mainly due to inappropriate application of chamber-based measurements and improper assumptions within process-based models. Here, we improved the Jayaweera-Mikkelsen (JM) model through multiplying the concentration of aqueous NH3 in ponded water by an activity coefficient that was determined based on high-frequency flux observations at Jingzhou station in Central China. We found that the improved JM model could reproduce the dynamics of observed NH3 flux (R2 = 0.83, n = 228, P < 0.001), while the original JM model without the consideration of activity of aqueous NH3 overstated NH3 flux by 54% during the periods of fertilization and pesticide application. The validity of the improved JM model was supported by a mass-balance-based indirect estimate at Jingzhou station and the independent flux observations from the other five stations across China. The NH3 volatilization losses that were further simulated by the improved JM model forced by actual wind speed were in general a half less than previous chamber-based estimates at six stations. Difference in wind speed between the inside and outside of the chamber and insufficient sampling frequency were identified as the primary and secondary causes for the overestimation in chamber-based estimations, respectively. Together, our findings suggest that an in-depth understanding of NH3 transfer process and its robust representation in models are critical for developing regional emission inventories and practical mitigation strategies of NH3.

Detection and attribution of nitrogen runoff trend in China's croplands.

Reliable detection and attribution of changes in nitrogen (N) runoff from croplands are essential for designing efficient, sustainable N management strategies for future. Despite the recognition that excess N runoff poses a risk of aquatic eutrophication, large-scale, spatially detailed N runoff trends and their drivers remain poorly understood in China. Based on data comprising 535 site-years from 100 sites across China's croplands, we developed a data-driven upscaling model and a new simplified attribution approach to detect and attribute N runoff trends during the period of 1990-2012. Our results show that N runoff has increased by 46% for rice paddy fields and 31% for upland areas since 1990. However, we acknowledge that the upscaling model is subject to large uncertainties (20% and 40% as coefficient of variation of N runoff, respectively). At national scale, increased fertilizer application was identified as the most likely driver of the N runoff trend, while decreased irrigation levels offset to some extent the impact of fertilization increases. In southern China, the increasing trend of upland N runoff can be attributed to the growth in N runoff rates. Our results suggested that increased SOM led to the N runoff rate growth for uplands, but led to a decline for rice paddy fields. In combination, these results imply that improving management approaches for both N fertilizer use and irrigation is urgently required for mitigating agricultural N runoff in China.

Evidence for the Importance of Atmospheric Nitrogen Deposition to Eutrophic Lake Dianchi, China.

Elevated atmospheric nitrogen (N) deposition has significantly influenced aquatic ecosystems, especially with regard to their N budgets and phytoplankton growth potentials. Compared to a considerable number of studies on oligotrophic lakes and oceanic waters, little evidence for the importance of N deposition has been generated for eutrophic lakes, even though emphasis has been placed on reducing external N inputs to control eutrophication in these lakes. Our high-resolution observations of atmospheric depositions and riverine inputs of biologically reactive N species into eutrophic Lake Dianchi (the sixth largest freshwater lake in China) shed new light onto the contribution of N deposition to total N loads. Annual N deposition accounted for 15.7% to 16.6% of total N loads under variable precipitation conditions, 2-fold higher than previous estimates (7.6%) for the Lake Dianchi. The proportion of N deposition to total N loads further increased to 27-48% in May and June when toxic blooms of the ubiquitous non-N2 fixing cyanobacteria Microcystis spp. are initiated and proliferate. Our observations reveal that reduced N (59%) contributes a greater amount than oxidized N to total N deposition, reaching 56-83% from late spring to summer. Progress toward mitigating eutrophication in Lake Dianchi and other bloom-impacted eutrophic lakes will be difficult without reductions in ammonia emissions and subsequent N deposition.

Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns.

The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P balance.

Hsa-miR-196a2 functional SNP is associated with severe toxicity after platinum-based chemotherapy of advanced nonsmall cell lung cancer patients in a Chinese population.

BACKGROUND: Rs11614913 is a polymorphism in hsa-miR-196a2 reported to alter mature microRNA expression and function. This single-nucleotide polymorphism (SNP) was reported to be associated with susceptibility and prognosis of lung cancer. METHODS: In this article, association study was performed to reveal the relation between SNP and response rate or severe toxicity after platinum-based regimen in advanced nonsmall cell lung cancer patients. RESULTS: By screening this polymorphism in 442 Chinese patients with MALDI-TOF Mass Spectrometer, significantly higher occurrence of grade 3 or 4 overall toxicity (P = 0.02) in response to treatment was found in patients with homozygous CC. After stratified analyses, association between rs11614912 and overall toxicity existed, especially in individuals treated with gemcitabine (P = 0.006) or cisplatin (P = 0.008), and in male patients (P = 0.02) or younger patients (P = 0.01). CONCLUSION: Our study confirmed that rs11614913 in hsa-miR-196a2 was associated with severe toxicity in lung cancer patients, and might help to improve individualized therapy in the future.

CTLA4 A49G polymorphism shows significant association with glioma risk in a Chinese population.

Cytotoxic T lymphocyte-associated antigen-4 (CTLA4) A49G is a polymorphism that is extensively studied in various cancers. To investigate whether it is associated with the occurrence of glioma in Chinese patients, we performed a case-control research study with 670 patients and 680 controls. In this group, we found that the genotype at this locus is significantly associated with glioma risk (GG vs. AA: P = 0.045; GG + AG vs. AA: P = 0.013). In some subgroups, G allele carriers are significantly less represented. We also observed significant correlations between the polymorphism genotype and glioma risk in patients with WHO histologic stages. We conclude that CTLA4 A49G might be a potential clinical biomarker for distinguishing persons with a high risk for developing gliomas.

Genome-wide prediction of G protein-coupled receptors in Verticillium spp.

G protein-coupled receptors (GPCRs) are critical factors in regulating morphogenesis, mating, infection and virulence in fungi. In this study, various computational strategies were applied to identify GPCR-like proteins from the genomes of both Verticillium dahliae and Verticillium albo-atrum. The putative GPCRs were distributed over 13 classes, and significantly, three of those represented novel classes of GPCR-like proteins in fungi. The three novel GPCRs had high levels of identity to their counterparts in higher eukaryotes, including Homo sapiens. The numbers of GPCR-like proteins in the two Verticillium spp. were similar to those seen in other filamentous fungi, such as Magnaporthe grisea, Neurospora crassa and Fusarium graminearum. Additionally, the carbon/amino acid receptors were divided into three different subclasses, indicating that differences among the GPCRs existed not only among different classes but also within classes. In conclusion, the identification and classification of GPCRs and their homology to some well-studied fungi will be an important starting point for future research in Verticillium spp.