Extreme precipitation accelerates nitrate leaching in the intensive agricultural region with thick unsaturated zones.

Nitrate accumulation in the soil profile in the intensive agricultural region has been widely concerned in the world. However, the changes in nitrate accumulation characteristics caused by climate change, such as extremely high precipitation, are not well quantified, particularly for the regions with thick unsaturated zones. Here, we resampled the soil profiles taken in normal year (2020) after extreme precipitation year (2021) (>800 cm) in three regions in the southern Loess Plateau (LP) with three different water managements including rainfed orchards (n = 10), well-irrigated orchards (n = 4) and canal-irrigated orchards (n = 8). The accumulation amounts, peak depths, and accumulation depths of nitrate soil profiles of the different regions of two years were compared. The results showed that average nitrate accumulation in normal year at the rainfed region (800-cm depth), well-irrigated region (800-cm depth) and canal-irrigated region (1400-cm depth) were 5995 kg N ha-1, 9765 kg N ha-1, and 19,608 kg N ha-1, respectively. Compared with 2020, extreme precipitation in 2021 led to 56-91% reductions (2060-3702 kg N ha-1) in nitrate accumulation in 0-200 cm soil layer, and average nitrate leaching into the aquifer was >1390 kg N ha-1 in the canal-irrigated region. Average migration depths of nitrate peak in rainfed, well-irrigated and canal-irrigated regions were 92 cm, 115 cm, and 188 cm, respectively; as for nitrate accumulation depths, they were 10 cm, 80 cm and 108 cm, respectively. Vertically, the dried soil layer and paleosol layer (high clay content) in the canal-irrigated region significantly hindered nitrate deep migration caused by the extreme precipitation. The result highlights that extreme precipitation significantly accelerated nitrate leaching in the deep soil profiles, and future vulnerability and risk assessment studies must account for the impacts of extreme precipitation on nitrate leaching.

Association of serum vitamin C levels with Asthma in adults: results of NHANES 2003-2006 and mendelian randomization study.

BACKGROUND: The protective effect of vitamin C as an antioxidant against asthma in adults remains controversial. This study used an observational study and Mendelian randomization (MR) analysis to investigate the association between adult asthma and serum vitamin C levels. METHODS: Using information from the National Health and Nutrition Examination Survey (NHANES) 2003-2006, we carried out an observational study. A multivariate logistic regression model was employed to examine the connection between adult asthma and serum vitamin C levels. We used the inverse-variance weighted (IVW) method of MR analysis as the primary method to analyze the causal effect of serum vitamin C levels on asthma in adults. RESULTS: A total of 8,504 participants were included in the observational study, including 639 in the asthma group and 7,865 in the non-asthma group. Before sample weighting, serum vitamin C was associated with a reduced risk of asthma in adults (OR = 0.798, 95% CI: 0.673-0.945, P = 0.009). After sample weighting, serum vitamin C was not associated with adult asthma risk (OR = 0.829, 95% CI: 0.660 ~ 1.042, P = 0.104). MR analysis showed no causal relationship between serum vitamin C and adult asthma in either the UK Biobank (OR = 0.957, 95% CI: 0.871 ~ 1.053, P = 0.370) or FinnGen (OR = 0.973, 95% CI: 0.824 ~ 1.149, P = 0.750) cohorts. CONCLUSION: Our study did not support a causal association between serum vitamin C levels and adult asthma risk. The relationship between serum vitamin C and adult asthma requires further research.

BRCA2 mutation in advanced lung squamous cell carcinoma treated with Olaparib and a PD-1 inhibitor: a case report.

Background: Mutations in the human breast cancer susceptibility gene 2 (breast cancer 2, BRCA2) increase the risk of breast, ovarian and other cancers. Olaparib, an oral poly[adenosine diphosphate (ADP)-ribose] polymerase (PARP) inhibitor, is usually prescribed to treat BRCA mutated tumors, especially breast and ovarian cancers. Programmed cell death-1 (PD-1) inhibitors have revolutionized the treatment of lung cancer and many other cancers by destroying the interaction between receptors with ligands in the tumor-immune microenvironment and enabling T cells to recognize and attack cancer cells. Case description: In our study, we report a patient with advanced BRCA2 lung squamous cell carcinoma who received platinum-based chemotherapy combined with paclitaxel. Seven months later, the disease progressed. BRCA2 mutations were detected in peripheral blood by next-generation sequencing. After 2 months of treatment with Olaparib combined with Cindilimab, the patient was in partial remission and the progression-free survival (PFS) lasted for 6 months, but the patient developed immune renal damage. Conclusions: This study adds to the clinical data for the treatment of BRCA2 mutant non-small cell lung cancer by demonstrating that lung squamous cell carcinoma has a good response to PARP inhibitors. It also serves as a reminder that there may still be some negative effects from targeted superimposed immunotherapy.

Competitive proton-trapping strategy enhanced anti-freezing organohydrogel fibers for high-strain-sensitivity wearable sensors.

Stretchable organohydrogel fibers are attracting considerable interest for next-generation flexible and wearable soft strain sensors due to their excellent stability in harsh environments. However, due to the uniformly distributed ions and reduced number of carriers in the whole material, the sensitivity of organohydrogel fibers under subzero temperature is not desirable, which significantly hinders their practical application. Herein, a newly competitive proton-trapping strategy was designed to obtain anti-freezing organohydrogel fibers for high-performance wearable strain sensors via a simple freezing-thawing process, in which tetraaniline (TANI), serving as the proton trapper, and representing the shortest repeated structural unit of polyaniline (PANI), was physically crosslinked with polyvinyl alcohol (PVA) (PTOH). The as-prepared PTOH fiber exhibited an outstanding sensing performance at -40 °C due to the unevenly distributed ion carriers and the highly breakable proton-migration pathways, with a high gauge factor of 24.6 at a strain of 200-300%. Moreover, the existence of hydrogen bonds between the TANI and PVA chains endowed PTOH with a high tensile strength (1.96 MPa) and toughness (8.0 MJ m-3). Accordingly, strain sensors made from PTOH fibers and knitted textiles could monitor human motions rapidly and sensitively, demonstrating their potential as wearable anti-freezing anisotropic strain sensors.

Differentiating between tuberculous and non-tuberculous pleural effusions using the pleural fluid ratio of 10× adenosine deaminase/lactate dehydrogenase.

Background: Adenosine deaminase (ADA) is a sensitive marker of tuberculous pleural effusion (TBPE). However, in pleural effusion (PE), the detection of ADA alone cannot be used to determine whether the increase in the ADA level is caused by the rising proportion of macrophages and lymphocytes in the cell components or by the increase in the total cell number. The diagnostic precision of ADA is probably restricted due to the false positive and negative results. Thus, we explored the clinical value of the ratio of PE ADA to lactate dehydrogenase (LDH) in differentiating between TBPE and non-TBPE. Methods: Patients hospitalized with PEs between January 2018 and December 2021 were retrospectively recruited for this study. We analyzed the values of ADA, LDH, and 10× ADA/LDH in the patients with TBPE and non-TBPE. We also determined the sensitivity, specificity, Youden index, and area under the curve for 10× ADA/LDH at different ADA levels and evaluated its diagnostic accuracy. Results: In total, 382 patients with PEs were included in the study. Among whom, 144 were diagnosed with TBPE, this supposes a "pre-test probability" >40%. It is quite high, 134 with malignant PEs, 19 with parapneumonic PEs, 43 with empyema, 24 with transudate PEs, and 18 with other types of PE of a known etiology. The ADA levels were positively correlated with the LDH levels in TBPE. LDH levels usually increase in response to cell damage or cell death. The 10× ADA/LDH level was significantly increased in the TBPE patients. In addition, the 10× ADA/LDH level increased as the ADA level increased in TBPE. To differentiate between TBPE and non-TBPE, the optimal cut-off value of 10× ADA/LDH at different ADA levels was assessed using receiver operating curves. At an ADA level >20 U/L, 10× ADA/LDH showed the best diagnostic performance, and had a specificity and sensitivity of 0.94 (95% CI: 0.84-0.98) and 0.95 (95% CI: 0.88-0.98), respectively. Conclusions: The 10× ADA/LDH dependent diagnostic index can be used to distinguish TBPE from non-TBPE and could be used to guide future clinical decisions.

Soil aggregation is more important than mulching and nitrogen application in regulating soil organic carbon and total nitrogen in a semiarid calcareous soil.

Evaluating soil aggregation and microbial activities within soil aggregates contributes to understanding carbon (C) and nitrogen (N) cycling. Here we examined soil aggregate distribution, C and N pools, and extracellular enzymatic activities (EEAs) in soil aggregates after 16-year mulching (CT, no mulch; RF, plastic-mulched ridges and straw-mulched furrows; SM, straw mulch) and N fertilization (0, 120, and 240 kg ha-1). RF and SM significantly increased macroaggregate formation and aggregate stability (MWD, mean weight diameter) but N rate did not. Mulching had similar effects on aggregate-associated SOC (soil organic C) and TN (total N), with the order SM > RF > CT in macroaggregates and macroaggregate-occluded microaggregates. N input significantly increased TN in most cases, whereas its effect on SOC was only significant in SM. Notably, the majority of SOC and TN was isolated in the macroaggregate-occluded silt and clay fractions. SOC, TN, microbial biomass C (MBC), and microbial biomass N (MBN) decreased as aggregate-size decreased, whereas C- and N-acquiring enzymes varied greatly across aggregate fractions. Mulching had greater effects than N-fertilization on soil C and N pools and EEAs, whilst SM performed more beneficial effects than RF on SOC, TN, MBC, MBN, and EEAs. MBC rather than SOC was associated with MWD in bulk soil, while significant relations between MWD and SOC were observed in macroaggregates and macroaggregate-occluded microaggregates. Partial least squares path modeling illustrated that soil aggregation was the most important factor affecting SOC and TN, followed by mulching and N addition. Regression analysis further revealed that α-glucosidase and leucine aminopeptidase were major variables mediating SOC and TN dynamics at the aggregate scale. This study highlights the importance of macroaggregate-occluded microaggregate fraction sensitively evaluating soil C and N dynamics, and straw mulch can effectively increase soil aggregation and stabilization of C and N in semiarid areas with infertile soils.

Long-term trajectories of BMI and cumulative incident metabolic syndrome: A cohort study.

Background: Body mass index (BMI) has been widely recognized as a risk factor for metabolic syndrome (MetS). However, the relationship between the trajectory of BMI and cumulative incident MetS is still unclear. We investigate the associations of long-term measurements of BMI with MetS among young adults in the China Health and Nutrition Survey. Methods: We enrolled individuals aged 10 to 20 at baseline with recorded BMI at each follow-up interview, and 554 participants were finally included in our study. The assessment and incidence of MetS were evaluated by blood tests and physical examinations in their adulthood. A latent class growth mixed model was used to identify three BMI trajectory patterns: a low baseline BMI with slow development (low-slow, n=438), a low baseline BMI with fast development (low-fast, n=66), and a high baseline BMI with fast development (high-fast, n=50). Logistic regression was used to explore the relationship between different BMI trajectories and the incidence of MetS. Result: During a follow-up of 16 years, 61 (11.01%) participants developed MetS. The combination of elevated triglycerides and reduced high-density lipoprotein cholesterol was most frequent in diagnosed MetS. In multivariate adjusted models, the low-fast and high-fast BMI trajectories showed a significantly higher risk of MetS than those with the low-slow BMI trajectory (low-high: OR = 3.40, 95% CI: 1.14-10.13, P < 0.05; high-fast: OR = 5.81, 95% CI: 1.63-20.69, P < 0.05). Conclusion: Our study identified three BMI trajectories in young adults and found that long-term measurements of BMI were also associated with cumulative incident MetS.

Association between malnutrition and contrast-associated acute kidney injury in congestive heart failure patients following coronary angiography.

Background: Previous studies have shown that malnutrition is very common in patients with congestive heart failure (CHF) and is closely related to the occurrence of acute kidney injury. However, the relationship between malnutrition and contrast-associated acute kidney injury (CA-AKI) is unclear. Method and results: We obtained data from 842 patients who were diagnosed with CHF following coronary angiography (CAG) or percutaneous coronary angiography (PCI) and had follow-up information from January 2013 to February 2016. The patients were divided into 3 groups according to the Controlling Nutritional Status Score before CAG or PCI procedure (Group 1: Normal; Group 2: Mild Malnutrition; Group 3: Moderate to Severe Malnutrition). The main endpoint was CA-AKI. Univariate and multivariable logistic regression analyses were performed. 556 (60.0%) patients suffered from malnutrition before CAG or PCI. During a median follow-up of 2.1 years, A total of 49 (5.82%) patients developed CA-AKI. Additionally, 5 (1.75%), 26 (6.27%) and 18 (12.77%) events were documented in patients with normal, mild and moderate or severe malnutrition, respectively (p < 0.01). In multivariable-adjusted models, patients with malnutrition showed a significantly higher incidence of CA-AKI than those in the normal group. Conclusion: Malnutrition is an independent risk factor for CA-AKI in CHF patients following CAG.

Infliximab in the treatment of tislelizumab-induced steroid-refractory immune checkpoint inhibitor-related pneumonia: case report and literature review.

Background: Infliximab has been recommended by the American Society of Clinical Oncology (ASCO) guidelines for the treatment of steroid-refractory immune checkpoint inhibitor-related pneumonia (CIP), but clinical evidence remains insufficient. In order to improve the level of diagnosis and treatment and rational use of infliximab in the treatment of CIP, a successful case is reported and the relevant literature is reviewed. Case Description: We report a 67-year-old male patient with small cell lung cancer (SCLC) who was admitted to hospital with rapidly worsening dyspnea and bilateral interstitial lung following PD-1 inhibitor (tislelizumab) combined with chemotherapy and radiation therapy. According to the comprehensive judgment of the patient's medical history, clinical symptoms, imaging manifestations, laboratory tests, exclusion of infection, heart failure and treatment response, the diagnosis of grade 4 CIP was made. The patient's condition did not improve after high-dose glucocorticoid and immunoglobulin therapy. After infliximab was added, the clinical manifestations and imaging were significantly improved, oxygenation index also gradually return to normal, then the patient was discharged smoothly. Conclusions: This report suggests that infliximab should be considered when high-dose glucocorticoids combined with immunoglobulin are ineffective for severe CIP. At the same time, this case indicates that inflammatory factors, especially tumor necrosis factor (TNF-α), may be prospective in predicting the efficacy of infliximab in the treatment of steroid-refractory CIP.

The association between prothrombin time-international normalized ratio and long-term mortality in patients with coronary artery disease: a large cohort retrospective study with 44,662 patients.

BACKGROUND: The association between prothrombin time-international normalized ratio (PT-INR) and long-term prognosis among patients with coronary artery disease (CAD) without atrial fibrillation or anticoagulant therapy was still unclear. We analyzed the association of PT-INR levels and long-term mortality in a large cohort of CAD patients without atrial fibrillation or using of anticoagulant drugs. METHODS: We obtained data from 44,662 patients who were diagnosed with CAD and had follow-up information from January 2008 to December 2018. The patients were divided into 4 groups (Quartile 1: PT-INR ≤ 0.96; Quartile2: 0.96 < PT-INR ≤ 1.01; Quartile3: 1.01 < PT-INR ≤ 1.06; Quartile4: PT-INR > 1.06). The main endpoint was long-term all-cause death. Kaplan-Meier curve analysis and Cox proportional hazards models were used to investigate the association between quartiles of PT-INR levels and long-term all-cause mortality. RESULTS: During a median follow-up of 5.25 years, 5613 (12.57%) patients died. We observed a non-linear shaped association between PT-INR levels and long-term all-cause mortality. Patients in high PT-INR level (Quartile4: PT-INR > 1.06) showed a significantly higher long-term mortality than other groups (Quartile2 or 3 or 4), (Compared with Quartile 1, Quartile 2 [0.96 < PT-INR ≤ 1.01], aHR = 1.00, 95% CI 0.91-1.00, P = 0.99; Quartile 3 [1.01 < PT-INR ≤ 1.06], aHR = 1.10, 95% CI 1.01-1.20, P = 0.03; Quartile 4 [PT-INR > 1.06], aHR = 1.33, 95% CI 1.22-1.45, P < 0.05). CONCLUSIONS: Our study demonstrates high levels of PT-INR were associated with an increased risk of all-cause mortality.

Vulnerability and driving factors of soil inorganic carbon stocks in Chinese croplands.

The long-term stability of soil inorganic carbon (SIC) and its minimum contribution towards global C cycle has been challenged, as recent studies have showed rapid decreases in SIC stocks in intensive agricultural systems. However, the extent of SIC losses and its driving factors remains unclear. Here, we compared changes in SIC density (SICD) in Chinese croplands between the 1980s and 2010s. The SIC contents in 1980s were obtained from second national soil survey (n = 949) and published studies (n = 47). The SIC contents in 2010s were based on resampling of soil profiles from the same locations during 2019 and 2020 (n = 30), as well as data from published studies and national soil survey (n = 903). We found that Chinese croplands have lost 27-38% of SICD from the 0-40 cm soil layer and that the soil pH has decreased by 0.53 units over the past 30 years. These SIC losses increased with the ratio of precipitation (P) to potential evapotranspiration (PET) and most notably with nitrogen (N) fertilization. The SICD decreased greatly in humid and semiarid regions, and these losses were enhanced by high N fertilization rates; however, the SICD increased in very arid regions. This analysis demonstrates that the water balance and N fertilization are major drivers leading to dramatic losses of SICD in croplands and, consequently, to decreases in soil fertility and functions.

Intensive vegetable production results in high nitrate accumulation in deep soil profiles in China.

A comprehensive understanding of the patterns and controlling factors of nitrate accumulation in intensive vegetable production is essential to solve this problem. For the first time, the national patterns and controlling factors of nitrate accumulation in soil of vegetable systems in China were analysed by compiling 1262 observations from 117 published articles. The results revealed that the nitrate accumulation at 0-100 cm, 100-200 cm, 200-300 cm, and >300 cm were 504, 390, 349, and 244 kg N ha-1, with accumulation rates of 62, 54, 19, and 16 kg N ha-1 yr-1 for plastic greenhouse vegetables (PG); for open field vegetables (OF), they were 264, 217, 228, and 242 kg N ha-1 with accumulation rates of 26, 24, 18, and 10 kg N ha-1 yr-1, respectively. Nitrate accumulation at 0-100 cm, 0-200 cm, and 0-400 cm accounted for 5%, 11%, and 17% of accumulated nitrogen (N) inputs for PG, and represented 4%, 9%, and 13% of accumulated N inputs for OF. Nitrogen input rates and soil pH had positive effects and soil organic carbon, water input rate, and carbon to nitrogen ratio (C/N) had negative effects on nitrate accumulation in root zone (0-100 cm soil). Nitrate accumulation in deep vadose zone (>100 cm soil) was positively correlated with N and water input rates, and was negatively correlated with soil organic carbon, C/N, and the clay content. Thus, for a given vegetable soil with relatively stable soil pH and soil clay content, reducing N and water inputs, and increasing soil organic carbon and C/N are effective measures to control nitrate accumulation.

High Nitrate Accumulation in the Vadose Zone after Land-Use Change from Croplands to Orchards.

Additional evidence indicates that the nitrate stored in the deep soil profile has an important role in regulating the global nitrogen (N) cycle. This study assessed the effects of land-use changes from croplands to intensive orchards (LUCO) on N surplus, nitrate accumulation in deep soil, and groundwater quality in the kiwifruit belt of the northern slope region of the Qinling Mountains, China. LUCO resulted in comparatively high N surplus in orchards (282 vs 1206 kg ha-1 yr-1, respectively). The average nitrate accumulation within the 0-10 m profiles of orchards was 7113 kg N ha-1, which was equal to approximately the total N surplus of 6 years of the orchards. The total nitrate stock within 0-10 m soil profiles of the kiwifruit belt was 266.5 Gg N, which was 3.5 times higher than the total annual N input. The nitrate concentrations of 97% of groundwater samples exceeded the WHO standard. The LUCO resulted in large nitrate storage in the vadose zone and caused serious contamination of groundwater. Our study highlights that nitrate accumulation in the vadose zone of an intensive land-use system is one of the main fates of surplus N and also a hotspot of nitrate accumulation.

Do soil property variations affect dicyandiamide efficiency in inhibiting nitrification and minimizing carbon dioxide emissions?

Nitrification inhibitors (NIs) are used to retard the nitrification process and reduce nitrogen (N) losses. However, the effects of soil properties on NI efficacy are less clear. Moreover, the direct and indirect effects of soil property variations on NI efficiency in minimizing carbon dioxide (CO2) emissions have not been previously studied. An incubation experiment was conducted for 40 days with two treatments, N (200 mg N-urea kg-1) and N + dicyandiamide (DCD) (20 mg DCD kg-1), and a control group (without the N) to investigate the response of ammonia-oxidizing bacteria (AOB) and archaea (AOA) to DCD application and the consequences for CO2, nitrous oxide (N2O) and ammonia (NH3) emissions from six soils from the Loess Plateau with different properties. The nitrification process completed within 6-18 days for the N treatment and within 30->40 days for the N + DCD treatment. AOB increased significantly with N fertilizer application, while this effect was inhibited in soils when DCD was applied. AOA was not sensitive to N fertilizer and DCD application. The nitrification rate was positively correlated with the clay (p < 0.05) and SOM contents (p < 0.01); DCD was more effective in loam soil with low SOM and high soil pH. Soil pH significantly was decreased with N fertilizer application, while it increased when DCD was applied. Moreover, DCD application decreased CO2 emissions from soils by 22%-172%; CO2 emissions were negatively correlated with the clay and SOM contents. DCD application decreased N2O emissions in each soil by 1.0- to 94-fold compared with those after N fertilizer application. In contrast, DCD application increased NH3 release from soils by 59-278%. NH3 volatilization was negatively correlated with clay (p < 0.05) and SOM (p < 0.01) contents and positively correlated with soil pH (p < 0.01). Therefore, soil texture, SOM and soil pH have significant effects on the DCD performance, nitrification process and gaseous emissions.

A gain-of-function mutation in PDR1 of Candida glabrata decreases EPA1 expression and attenuates adherence to epithelial cells through enhancing recruitment of the Mediator subunit Gal11A.

Genetic studies have revealed critical roles of transcription factor Pdr1 and the Mediator subunit Gal11A in regulating azole resistance in Candida glabrata. Recently, PDR1 gain-of-function (GOF) mutations have been shown to not only increase azole resistance but also enhance adherence during C. glabrata infection. However, mechanism of how Pdr1 regulates adherence, especially the implication of PDR1 GOF mutations in the regulation of the major adhesin gene EPA1, remains uncharacterized. Initially, we unexpectedly observed that expression of PDR1 harbouring GOF mutation G346D down-regulated EPA1 transcription and attenuated adherence to epithelial cells in different strain backgrounds. Given that PDR1 GOF mutations have been previously regarded as stimulators for adherence of this species, these findings prompted us to explore the regulation of EPA1 by wild-type Pdr1 and Pdr1 harbouring G346D mutation. Epitope tagged version of Pdr1 and Gal11A were utilized to determine the association of Pdr1 and Gal11A with EPA1 promoter. A combination of approaches including deletion, molecular, and biochemical assays showed that EPA1 is a direct target of Pdr1, and demonstrated for the first time that PDR1 G346D mutation decreases EPA1 expression and attenuates adherence to epithelial cells via enhancing recruitment of Gal11A. Taken together, our data propose a critical role of Gal11A in Pdr1-regulated EPA1 expression and adherence to epithelial cells, which could be utilized a novel therapeutic target for the treatment of hyper-adherent C. glabrata infection.

Crystal structure of bovine herpesvirus 1 glycoprotein D bound to nectin-1 reveals the basis for its low-affinity binding to the receptor.

Bovine herpesvirus 1 (BHV-1) has received increasing attention for its potential oncolytic applications. BHV-1 recognizes nectin-1 for cell entry via viral glycoprotein D (gD) but represents a low-affinity nectin-1 binding virus. The molecular basis underlying this low receptor-binding affinity, however, remains unknown. Here, the crystal structures of BHV-1 gD in the free and nectin-1-bound forms are presented. While showing an overall resembled nectin-1 binding mode to other alphaherpesvirus gDs, BHV-1 gD has a unique G-strand/α2-helix interloop that disturbs gD/nectin-1 interactions. Residue R188 residing in this loop is observed to otherwise cause strong steric hindrance with the bound receptor, making a large conformational change of the loop a prerequisite for nectin-1 engagement. Subsequently, substitution of R188 with glycine markedly enhances the affinity of the BHV-1-gD/nectin-1 interaction (by about fivefold). These structural and functional data delineate the receptor-recognition basis for BHV-1, which might facilitate BHV-1-based oncolytic design in the future.

How much nitrogen does Africa need to feed itself by 2050?

Nitrogen (N) fertilizers are very important for global food self-sufficiency (FSS), particularly for Africa, where the N input in agriculture is very low. This is the first work which studies and calculates the amount of N fertilizer that each country in Africa needs to feed itself by 2050. In this study, we used five different scenarios of inorganic fertilizer N (IFN) use and human diets to calculate the amount of N fertilizer needed to achieve FSS in Africa by 2050 and analyze the changes in N budget; N losses and N use efficiency (NUE). These scenarios include 1) business as usual (BAU), 2) equitable diet (EqD; self-sufficiency), 3) an IFN input 20% less than the EqD (S1), 4) an IFN input 40% less than the EqD (S2), and 5) a 20% increase in IFN input relative to the EqD (S3). Under the BAU scenario, production trends continue as they have over the past five decades, including an unhealthy human diet. In the EqD scenario, the priority is to meet the local demand for both animal and plant proteins with a healthy human diet. Under the EqD scenario, increasing the total N input from 35 kg N ha-1 yr-1 to 181 kg N ha-1 yr-1 during 2016-2050 is needed to achieve FSS in Africa. This increase in N fertilizer use represents unprecedented N inputs to African terrestrial ecosystems - at least 52 Tg N yr-1 - which would lead to inevitable increases in N losses. We also found that the NUE would decrease from 63% during 2010-2016 to 50% by 2050, whereas the total N surplus would increase from 13 kg N ha-1 yr-1 to 90 kg N ha-1 yr-1 by 2050. The estimated gaseous emissions would increase from 8 kg N ha-1 yr-1 to 61 kg N ha-1 yr-1 by 2050. Our findings conclude that, it is very important to consider the high N losses in Africa if the EqD scenario is applied. The S1 and S2 scenarios result in much less environmental N loss, and better NUE compared with the EqD scenario. Therefore, based on these findings we can recommend the implementation of the S2 scenario with an IFN dose of 77 kg N ha-1 yr-1, in parallel with the use of modern agricultural techniques and the increased use of organic inputs.

Dramatic loss of inorganic carbon by nitrogen-induced soil acidification in Chinese croplands.

Intensive crop production systems worldwide, particularly in China, rely heavily on nitrogen (N) fertilization, but left more than 50% of fertilizer N in the environment. Nitrogen (over) fertilization and atmospheric N deposition induce soil acidification, which is neutralized by soil inorganic carbon (SIC; carbonates), and carbon dioxide (CO2 ) is released to the atmosphere. For the first time, the loss of SIC stocks in response to N-induced soil acidification was estimated for Chinese croplands from 1980 to 2020 and forecasts were made up to 2100. The SIC stocks in croplands in 1980 were 2.16 Pg C (16.3 Mg C/ha) in the upper 40 cm, 7% (0.15 Pg C; 1.1 Mg C/ha) of which were lost from 1980 to 2020. During these 40 years, 7 million ha of cropland has become carbonate free. Another 37% of the SIC stocks may be lost up to 2100 in China, leaving 30 million ha of cropland (37.8%) without carbonates if N fertilization follows the business-as-usual (BAU) scenario. Compared to the BAU scenario, the reduction in N input by 15%-30% after 2020 (scenarios S1 and S2) will decrease carbonate dissolution by 18%-41%. If N input remains constant as noted in 2020 (S3) or decreases by 1% annually (S4), a reduction of up to 52%-67% in carbonate dissolution is expected compared to the BAU scenario. The presence of CaCO3 in the soil is important for various processes including acidity buffering, aggregate formation and stabilization, organic matter stabilization, microbial and enzyme activities, nutrient cycling and availability, and water permeability and plant productivity. Therefore, optimizing N fertilization and improving N-use efficiency are important for decreasing SIC losses from acidification. N application should be strictly calculated based on crop demand, and any overfertilization should be avoided to prevent environmental problems and soil fertility decline associated with CaCO3 losses.

Will income inequality influence the abatement effect of renewable energy technological innovation on carbon dioxide emissions?

Environmental pollution and income inequality have become two salient issues in China. To achieve a green economic transformation, China urgently needs to develop renewable energy technologies to reduce carbon dioxide (CO2) emissions. However, the relationship among income inequality, renewable energy technological innovation (RETI) and CO2 emissions has not received sufficient attention in the current literature. Based on Chinese provincial panel data from 2000 to 2015, this paper adopts a panel fixed effect regression model and a panel threshold model to perform an analysis on the nonlinear relationship among these factors. The results show that (1) RETI is conducive to reducing per capita CO2 emissions (PCE). However, with an increase in income inequality, the abatement effect of RETI on per capita CO2 emissions will be hindered, and RETI will even positively contribute to PCE. (2) The panel threshold model shows that the impact of RETI on PCE has a significant single-threshold effect with regard to income inequality. When income inequality is lower than the threshold value, the impact of RETI on PCE is not significant. However, above the threshold value, that is, within the interval of higher income inequality, an increase in RETI will positively contribute to PCE. Finally, from the perspectives of income inequality and RETI, relevant policy implications are put forward for achieving the transformation of a low-carbon economy.

Strategies to mitigate nitrate leaching in vegetable production in China: a meta-analysis.

Nitrate leaching is a main nitrogen (N) loss pathway in vegetable production. Although there are numerous mitigation practices that control nitrate leaching, an integrated assessment of these measures is lacking. Thus, we conducted a meta-analysis to integrate the assessment of strategies for controlling nitrate leaching from vegetable systems in China. The main strategies included improved N fertilizer management (INFM), reduced water management (RWM), comprehensive regulation of N fertilizer and water management (CFWM), and catch crops (CCs). Each mitigation measure decreased nitrate leaching significantly and did not reduce vegetable yields. CFWM reduced nitrate leaching the most at 41% on average, followed by CCs, RWM, and INFM (35%, 24%, and 22%, respectively). The nitrate leaching scaled yields (NLSY, defined as yield divided by the quantity of nitrate leaching) were significantly increased by 87%, 44%, 32%, and 27% for CFWM, CCs, INFM, and RWM, respectively. The efficacies of the strategies were dependent on soil properties. CFWM, INFM, and RWM were more effective in soils with low pH and coarse texture than in other soils. In conclusion, the risk of nitrate leaching from vegetable production systems is high, and INFM and CFWM are suggested to decrease nitrate leaching from vegetable production.