Warming-Induced Stimulation of Soil N2O Emissions Counteracted by Elevated CO2 from Nine-Year Agroecosystem Temperature and Free Air Carbon Dioxide Enrichment

Globally, agricultural soils account for approximately one-third of anthropogenic emissions of the potent greenhouse gas and stratospheric ozone-depleting substance nitrous oxide (N2O). Emissions of N2O from agricultural soils are affected by a number of global change factors, such as elevated air temperatures and elevated atmospheric carbon dioxide (CO2). Yet, a mechanistic understanding of how these climatic factors affect N2O emissions in agricultural soils remains largely unresolved. Here, we investigate the soil N2O emission pathway using a 15N tracing approach in a nine-year field experiment using a combined temperature and free air carbon dioxide enrichment (T-FACE). We show that the effect of CO2 enrichment completely counteracts warming-induced stimulation of both nitrification- and denitrification-derived N2O emissions. The elevated CO2 induced decrease in pH and labile organic nitrogen (N) masked the stimulation of organic carbon and N by warming. Unexpectedly, both elevated CO2 and warming had little effect on the abundances of the nitrifying and denitrifying genes. Overall, our study confirms the importance of multifactorial experiments to understand N2O emission pathways from agricultural soils under climate change. This better understanding is a prerequisite for more accurate models and the development of effective options to combat climate change.

Soil recalcitrant but not labile organic nitrogen mineralization contributes to microbial nitrogen immobilization and plant nitrogen uptake

Soil organic nitrogen (N) mineralization not only supports ecosystem productivity but also weakens carbon and N accumulation in soils. Recalcitrant (mainly mineral-associated organic matter) and labile (mainly particulate organic matter) organic materials differ dramatically in nature. Yet, the patterns and drivers of recalcitrant (MNrec) and labile (MNlab) organic N mineralization rates and their consequences on ecosystem N retention are still unclear. By collecting MNrec (299 observations) and MNlab (299 observations) from 57 15N tracing studies, we found that soil pH and total N were the master factors controlling MNrec and MNlab, respectively. This was consistent with the significantly higher rates of MNrec in alkaline soils and of MNlab in natural ecosystems. Interestingly, our analysis revealed that MNrec directly stimulated microbial N immobilization and plant N uptake, while MNlab stimulated the soil gross autotrophic nitrification which discouraged ammonium immobilization and accelerated nitrate production. We also noted that MNrec was more efficient at lower precipitation and higher temperatures due to increased soil pH. In contrast, MNlab was more efficient at higher precipitation and lower temperatures due to increased soil total N. Overall, we suggest that increasing MNrec may lead to a conservative N cycle, improving the ecosystem services and functions, while increasing MNlab may stimulate the potential risk of soil N loss.

Root rot destabilizes the Sanqi rhizosphere core fungal microbiome by reducing the negative connectivity of beneficial microbes

The stability of microbial communities, especially among core taxa, is essential for supporting plant health. However, the impacts of disease infection on the stability of rhizosphere fungal core microbiome remain largely unexplored. In this study, we delved into the effects of root rot infestation on the community structure, function, network complexity, and stability of Sanqi fungal core microbiomes, employing amplicon sequencing combined with co-occurrence network and cohesion analyses. Our investigation revealed that root rot disease led to a decrease in the α-diversity but an increase in the β-diversity of the Sanqi fungal core microbiomes in the rhizosphere. Notably, Ilyonectria, Plectosphaerella, and Fusarium emerged as indicator species in the rhizosphere core microbiome of root rot-infected Sanqi plants, while Mortierella predominated as the dominant biomarker taxa in healthy soils. Additionally, root rot diminished the complexity and modularity of the rhizosphere networks by reducing the metrics associated with nodes, edges, degrees, and modularity. Furthermore, root rot resulted in a reduction in the proportion of negative connections in the network and the negative/positive cohesion of the entire core fungal microbiome. Particularly noteworthy was the observation that root rot infection destabilized the rhizosphere core fungal microbiome by weakening the negative connectivity associated with beneficial agents. Collectively, these results highlight the significance of the negative connectivity of beneficial agents in ensuring the stability of core microbial community.IMPORTANCERoot rot disease has been reported as the most devastating disease in the production process of artificial cultivated Sanqi ginseng, which seriously threatens the Sanqi industry. This study provides valuable insights into how root rot influences microbial relationships within the community. These findings open up opportunities for disease prevention and the promotion of plant health by regulating microbial interactions. In summary, the research sheds light on the ecological consequences of root rot on rhizosphere fungal microbiomes and offers potential strategies for managing soil-borne diseases and enhancing plant health.

Intraosseous schwannoma of the mandible: new case series, literature update, and proposal of a classification

Intraosseous schwannoma of the mandible is rare, with diagnostic and therapeutic challenges. The aims of this study were to report new cases of intraosseous schwannoma of the mandible and to propose a clinical classification, providing suggestions for treatment methods. The cases of 13 patients treated at the authors' hospital and 86 cases reported previously in the literature were reviewed. The most common clinical feature was facial swelling (60/93). The rate of cortical thinning or expansion was 44.8% (43/96); widening of the inferior alveolar nerve canal on radiographs was observed in 15 patients.

Global patterns of soil available N production by mineralization-immobilization turnover in the tropical forest ecosystems

Available N (Navail) is important to nurish plant-microbial system and sequestrate carbon (C) in terrestrial ecosystems. For forest ecosystem, Navail is usually calculated as the sum of N2 fixation (NN2-fixed), N deposition (Ndeposition) and soil available N production (Navail-soil), in which Navail-soil determined the Navail production and its temporal changes. While, there is still a lack of Navail-soil estimation at the global and regional level due to the temporal and spatial variability of influencing factors, such as climate and soil physicochemical properties. By assembling a dataset of gross rates of soil N mineralization (GRmin), immobilization of ammonium (NH4+) (GRac) and nitrate (NO3-) (GRnc), as well as their corresponding geographic information, climate and main soil physicochemical properties, the Navail-soil produced from organic N (Norg) mineralization and inorganic N (Ninorg) immobilization turnover (MIT) was calculated via building a random forest (RF) model in global tropical forests. The results revealed a good fit between the observed and predicted GRmin (R2 = 0.76), GRac (R2 = 0.77) and GRnc (R2 = 0.67). We further estimated that the total mineralized N, immobilized NH4+ and NO3- was 23.97 (10.48-37.46), 17.98 (5.81-30.15) and 4.86 (1.46-8.26) Pg N year-1, respectively, leading to the total Navail-soil of 1.13 (-0.95-3.21) Pg N year-1. Referring to the reported average density of NN2-fixed and Ndeposition, the total NN2-fixed and Ndeposition was 0.03-0.05 and 0.01 Pg N year-1, respectively, by producting density and square meter of global tropic forest. Then the total Navail of global tropic forest ecosystem was 1.18 (-0.91-3.27) Pg N year-1 (Navail-soil + NN2-fixed + Ndeposition). According to the tight stoichiometric relationship between C and N in the production of gross primary productivity (GPP) and soil respiration (Rs), C:N ratio of 31.8-41.9 and 22.7-48.2 was calculated, respectively, which all fall into the C:N ratio range of plants and litter (13.9-75.9) in tropical forest ecosystem. These results confirmed the prediction of Navail-soil production from MIT was in line with theoretic estimates by applying RF machine learning. To our knowledge, this is the first estimation of Navail-soil and the results provide the theoretical basis to evaluate soil C sequestration potential in tropical (e.g. southern America, southeast Asia and Africa) forest ecosystem.

[Efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation in the treatment of secondary acute myeloid leukemia]

Objective: To evaluate the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with secondary acute myeloid leukemia (sAML) . Methods: In this multicenter, retrospective clinical study, adult patients aged ≥18 years who underwent allo-HSCT for sAML at four centers of the Zhejiang Hematopoietic Stem Cell Transplantation Collaborative Group from January 2014 to November 2022 were included, and the efficacy and prognostic factors of allo-HSCT were analyzed. Results: A total of 95 patients were enrolled; 66 (69.5%) had myelodysplastic syndrome-acute myeloid leukemia (MDS-AML) , 4 (4.2%) had MDS/MPN-AML, and 25 (26.3%) had therapy-related AML (tAML) . The 3-year CIR, LFS, and overall survival (OS) rates were 18.6% (95% CI 10.2%-27.0%) , 70.6% (95% CI 60.8%-80.4%) , and 73.3% (95% CI 63.9%-82.7%) , respectively. The 3-year CIRs of the M-AML group (including MDS-AML and MDS/MPN-AML) and the tAML group were 20.0% and 16.4%, respectively (P=0.430) . The 3-year LFSs were 68.3% and 75.4%, respectively (P=0.176) . The 3-year OS rates were 69.7% and 75.4%, respectively (P=0.233) . The 3-year CIRs of the groups with and without TP53 mutations were 60.0% and 13.7%, respectively (P=0.003) ; the 3-year LFSs were 20.0% and 76.5%, respectively (P=0.002) ; and the 3-year OS rates were 40.0% and 77.6%, respectively (P=0.002) . According to European LeukmiaNet 2022 (ELN2022) risk stratification, the 3-year CIRs of patients in the low-, intermediate-, and high-risk groups were 8.3%, 17.8%, and 22.6%, respectively (P=0.639) . The three-year LFSs were 91.7%, 69.5%, and 65.6%, respectively (P=0.268) . The 3-year OS rates were 91.7%, 71.4%, and 70.1%, respectively (P=0.314) . Multivariate analysis revealed that advanced disease at allo-HSCT and TP53 mutations were independent risk factors for CIR, LFS, and OS. Conclusion: There was no significant difference in the prognosis of patients who underwent allo-HSCT among the MDS-AML, MDS/MPN-AML, and tAML groups. Advanced disease at transplantation and TP53 mutations were poor prognostic factors. ELN2022 risk stratification had limited value for predicting the prognosis of patients with sAML following allo-HSCT.

Global patterns and controls of yield and nitrogen use efficiency in rice

Factors influencing rice (Oryza sativa L.) yield mainly include nitrogen (N) fertilizer, climate and soil properties. However, a comprehensive analysis of the role of climatic factors and soil physical and chemical properties and their interactions in controlling global yield and nitrogen use efficiency (e.g., agronomic efficiency of N (AEN)) of rice is still pending. In this article, we pooled 2293 observations from 363 articles and conducted a global systematic analysis. We found that the global mean yield and AEN were 6791 ± 48.6 kg ha-1 season-1 and 15.6 ± 0.29 kg kg-1, respectively. Rice yield was positively correlated with latitude, N application rate, soil total and available N, and soil organic carbon, but was negatively correlated with mean annual temperature (MAT) and soil bulk density. The response of yield to soil pH followed the parabolic model, with the peak occurring at pH = 6.35. Our analysis indicated that N application rate, soil total N, and MAT were the main factors driving rice yield globally, while precipitation promoted rice yield by enhancing soil total N. N application rate was the most important inhibitor of AEN globally, while soil cation exchange capacity (CEC) was the most important stimulator of AEN. MAT increased AEN through enhancing soil CEC, but precipitation decreased it by decreasing soil CEC. The yield varies with climatic zones, being greater in temperate and continental regions with low MAT than in tropical regions, but the opposite was observed for AEN. The driving factors of yield and AEN were climatic zone specific. Our findings emphasize that soil properties may interact with future changes in temperature to affect rice production. To achieve high AEN in rice fields, the central influence of CEC on AEN should be considered.

The loss of microbial autotoxin degradation functions is associated with the decline of beneficial bacterial agents induced by phenolic acids

Continuous cultivation of medicinal plants can disrupt the rhizosphere's microbial community. There is still a need to know about the beneficial bacterial community, their putative drivers, and the potential functions they may have. This study used different growth years of Sanqi ginseng (Panax notoginseng) with root rot to look at the beneficial microbial community structure, the function of microbial carbon source utilization, and the function of rhizosphere soil metabolism. The beneficial bacterial community changed and the relative abundance of beneficial agents was suppressed significantly with the successive Sanqi ginseng plantings. The carbon source utilization capacity and diversity increased significantly, whereas three autotoxin degradation-related pathways (biosynthesis of other secondary metabolites, metabolism of terpenoids and polyketides, and xenobiotics biodegradation and metabolism) were downregulated considerably with planting year extended. The changes in the beneficial agents were driven by the shifts in phenolic acid profiles, and the decline of beneficial microbes led to the loss of microbial autotoxin degradation functions. Overall, these results provide insight into beneficial microbes, microbial functions, phenolic acids, and their interactions, and these findings are essential for maintaining healthy and sustainable cultivation of Sanqi ginseng. IMPORTANCE Sanqi ginseng is a valuable perennial Chinese herb with various benefits for human health. However, continuous cultivation causes a high incidence of root rot disease, which leads to decreased yield and serious economic losses and ultimately impedes the sustainable development of Chinese medicine production. The significance of this study is to reveal the pattern of changes in beneficial bacteria and their related functions in root rot diseased rhizosphere with the successive planting years of Sanqi ginseng. This study found that the decline of beneficial bacterial agents mediated by phenolic acid profiles appears to be associated with the loss of microbial autotoxin degradation functions. This result may have new implications for deciphering the causes of Sanqi ginseng's continuous cropping obstacles.

Invited review: Good practices in genome-wide association studies to identify candidate sequence variants in dairy cattle

Genotype data from dairy cattle selection programs have greatly facilitated GWAS to identify variants related to economic traits. Results can enhance the accuracy of genomic prediction, analyze more complex models that go beyond additive effects, elucidate the genetic architecture of a trait, and finally, decipher the underlying biology of traits. The entire process, comprising data generation, quality control, statistical analyses, interpretation of association results, and linking results to biology should be designed and executed to minimize the generation of false-positive and false-negative associations and misleading links to biological processes. This review aims to provide general guidelines for data analysis that address data quality control, association tests, adjustment for population stratification, and significance evaluation to improve the reliability of conclusions. We also provide guidance on post-GWAS strategy and the interpretation of results. These guidelines are tailored to dairy cattle, which are characterized by long-range linkage disequilibrium, large half-sib families, and routinely collected phenotypes, requiring different approaches than those applied in human GWAS. We discuss common limitations and challenges that have been overlooked in the analysis and interpretation of GWAS to identify candidate sequence variants in dairy cattle.

Attribution and driving force of nitrogen losses from the Taihu Lake Basin by the InVEST and GeoDetector models

Quantifying temporal and spatial changes in reactive nitrogen (Nr) losses from a watershed and exploring its main drivers are the key to watershed water quality improvements. Huge Nr losses continue to threaten the safety of the water environment in the Taihu Lake Basin (TLB). Here, the InVEST and GeoDetector models were combined to estimate Nr losses in the TLB from 1990 to 2020 and explore driving forces. Different scenarios for Nr losses were compared, showing that Nr loss peaked at 181.66 × 10³ t in 2000. The key factors affecting Nr loss are land use, followed by elevation, soil, and slope factors, and their mean q-values were 0.82, 0.52, 0.51, and 0.48, respectively. The scenario analysis revealed that Nr losses increased under the business-as-usual and economic development scenarios, while ecological conservation, increased nutrient use efficiency, and reduced nutrient application all contribute to a reduction in Nr losses. The findings provide a scientific reference for Nr loss control and future planning in the TLB.

Effects of Solidago canadensis L. on mineralization-immobilization turnover enhance its nitrogen competitiveness and invasiveness

The effects of exotic plants on soil nitrogen (N) transformations may influence species invasion success. However, the complex interplay between invasive plant N uptake and N transformation in soils remains unclear. In the present study, a series of ¹⁵N-labeled pot experiments were carried out with Solidago canadensis L. (S. canadensis), an invasive plant, and the Ntrace tool was used to clarify the preferred inorganic N form and its effects on soil N transformation. According to the results, nitrate-N (NO₃^--N) uptake rates by S. canadensis were 2.38 and 2.28 mg N kg^-1 d^-1 in acidic and alkaline soil, respectively, which were significantly higher than the ammonium-N (NH₄⁺-N) uptake rates (1.76 and 1.56 mg N kg^-1 d^-1, respectively), indicating that S. canadensis was a NO₃^--N-preferring plant, irrespective of pH condition. Gross N mineralization rate was 0.41 mg N kg^-1 d^-1 in alkaline soil in the presence of S. canadensis L., which was significantly lower than that in the control (no plant, CK, 2.44 mg N kg^-1 d^-1). Gross autotrophic nitrification rate also decreased from 5.95 mg N kg^-1 d^-1 in the CK to 0.04 mg N kg^-1 d^-1 in the presence of S. canadensis in alkaline soil. However, microbial N immobilization rate increased significantly from 1.09 to 2.16 mg N kg^-1 d^-1, and from 0.02 to 2.73 mg N kg^-1 d^-1 after S. canadensis planting, in acidic and alkaline soil, respectively. Heterotrophic nitrification rate was stimulated in the presence of S. canadensis to provide NO₃^--N to support the N requirements of plants and microbes. The results suggested that S. canadensis can influence the mineralization-immobilization turnover (MIT) to optimize its N requirements while limiting N supply for other plants in the system. The results of the present study enhance our understanding of the competitiveness and mechanisms of invasion of alien plants.

[Bioinformatics analysis in metagenomic next-generation sequencing of pathogenic microorganisms: current status and challenges]

The clinical application of metagenomic next-generation sequencing (mNGS) in the diagnosis of unknown pathogenic infections and critical infections has become increasingly valuable. Due to the huge volume of mNGS data and the complexity of clinical diagnosis and treatment, mNGS has difficulties in data analysis and interpretation in practical application. Therefore, in the process of clinical practice, it is crucial to grasp the key points of bioinformatics analysis and establish a standardized bioinformatics analysis process, which is an important step in the transformation of mNGS from laboratory to clinic. At present, bioinformatics analysis of mNGS has made great progress, but with the high requirements of clinical standardization of bioinformatics analysis and the development of computer technology, bioinformatics analysis of mNGS is also facing new challenges. This article mainly elaborates on quality control, and identification and visualization of pathogenic bacteria.

Deciphering the Synergies of Reductive Soil Disinfestation Combined with Biochar and Antagonistic Microbial Inoculation in Cucumber Fusarium Wilt Suppression Through Rhizosphere Microbiota Structure

Application of reductive soil disinfestation (RSD), biochar, and antagonistic microbes have become increasingly popular strategies in a microbiome-based approach to control soil-borne diseases. The combined effect of these remediation methods on the suppression of cucumber Fusarium wilt associated with microbiota reconstruction, however, is still unknown. In this study, we applied RSD treatment together with biochar and microbial application of Trichoderma and Bacillus spp. in Fusarium-diseased cucumbers to investigate their effects on wilt suppression, soil chemical changes, microbial abundances, and the rhizosphere communities. The results showed that initial RSD treatment followed by biochar amendment (RSD-BC) and combined applications of microbial inoculation and biochar (RSD-SQR-T37-BC) decreased nitrate concentration and raised soil pH, soil organic carbon (SOC), and ammonium in the treated soils. Under RSD, the applications of Bacillus (RSD-SQR), Trichoderma (RSD-T37), and biochar (RSD-BC) suppressed wilt incidence by 26.8%, 37.5%, and 32.5%, respectively, compared to non-RSD treatments. Moreover, RSD-SQR-T37-BC and RSD-T37 caused greater suppressiveness of Fusarium wilt and F. oxysporum by 57.0 and 33.5%, respectively. Rhizosphere beta diversity and alpha diversity revealed a difference between RSD-treated and non-RSD microbial groups. The significant increase in the abundance, richness, and diversity of bacteria, and the decrease in the abundance and diversity of fungi under RSD-induced treatments attributed to the general suppression. Identified bacterial (Bacillus, Pseudoxanthomonas, Flavobacterium, Flavisolibacter, and Arthrobacter) and fungal (Trichoderma, Chaetomium, Cladosporium, Psathyrella, and Westerdykella) genera were likely the potential antagonists of specific disease suppression for their significant increase of abundances under RSD-treated soils and high relative importance in linear models. This study infers that the RSD treatment induces potential synergies with biochar amendment and microbial applications, resulting in enhanced general-to-specific suppression mechanisms by changing the microbial community composition in the cucumber rhizosphere.

Biochar application can mitigate NH3 volatilization in acidic forest and upland soils but stimulates gaseous N losses in flooded acidic paddy soil

Biochar (BC) has attracted attention for carbon sequestration, a strategy to mitigate climate change and alleviate soil acidification. Most meta-analyses have insufficiently elaborated the effects of BC on soil N transformation so the practical importance of BC could not be assessed. In this study, a ¹⁵N tracing study was conducted to investigate the effects of BC amendment on soil gross N transformations in acidic soils with different land-use types. The results show that the BC amendment accelerated the soil gross mineralization rate of labile organic N to NH₄⁺ (M_Nlab) (3 %-128 %) which was associated with an increase in total nitrogen. BC mitigated NH₃ volatilization (V_NH3) (52 %-99 %) in upland and forest soils due to NH₄⁺/NH₃ adsorption, while it caused higher gaseous N losses (NH₃ and N₂O) in flooded paddy soils. An important function was the effect of BC addition on NH₄⁺ oxidation (O_NH4). While O_NH4 increased (4 %-19 %) in upland soils, it was inhibited (34 %-71 %) in paddy soils and did not show a response in forest soils. Overall, the BC amendment reduced the potential risk of N loss (P_RL), especially in forest soils (82 %-98 %). This study also shows that the BC effect on soil N cycling is land-use specific. The suitability of practices including BC hinges on the effects on gaseous N losses.

Increasing Nitrogen Losses Due to Changing Food Consumption Patterns in Bayannur City, China

Increasing urbanization and affluence have led to changes in food consumption patterns. The application of nitrogen (N) fertilizers ensures food security but also leads to environmental pollution due to N losses, through processes such as acidification, eutrophication, and greenhouse gas emissions. To clarify whether changes in food consumption patterns could increase N losses and to explore sustainable food system pathways, this study integrated the Chinese Food System Dashboard and the Nutrient Flows in Food Chains, Environment and Resources Use model to quantify and compare the link between food consumption and N losses in different agricultural regions using a case study of Bayannur City in the Yellow River Basin from 2000 to 2016. During the study period, Bayannur's food consumption pattern changed from a "high carbohydrate and pork pattern" to a "high fiber and herbivore pattern", which represents a shift from low to high N consumption. The per-capita food consumption decreased by 11.55% from 425.41 kg cap^-1, whereas the per-capita N losses increased by 12.42% from 35.60 kg N cap^-1. The average share of the plant-oriented and animal-oriented food supply in these losses was 53.39% and 46.61%, respectively. There were differences in the food consumption patterns and N losses in Bayannur's farming, farming-pastoral, and pastoral regions. The changes in N losses were most significant in the pastoral region. The N losses to the environment increased sharply by 112.33% from 22.75 g N cap^-1 over the past 16 years. The low level of economic development in Bayannur resulted in a shift in the food consumption pattern to a high N consumption. Four measures to protect food security and reduce the food N cost were proposed: (1) increasing the wheat planting area and maintaining the existing corn one; (2) expanding the scale of high-quality alfalfa planting; (3) enhancing the area of oat grass and wheat replanting; and (4) using modern planting technology.

High carbon resource diversity enhances the certainty of successful plant pathogen and disease control

The host-associated microbiome highly determines plant health. Available organic resources, such as food for microbes, are important in shaping microbial community structure and multifunctionality. However, how using organic resources precisely manipulates the soil microbiome and makes it supportive of plant health remains unclear. Here, we experimentally tested the influence of carbon resource diversity on the microbial trophic network and pathogen invasion success in a microcosm study. We further explored how resource diversity affects microbial evenness, community functions, and plant disease outcomes in systems involving tomato plants and the in vivo soil microbiome. Increasing available resource diversity altered trophic network architecture, increased microbial evenness, and thus increased the certainty of successful pathogen control. By contrast, the invasion resistance effects of low resource diversity were less effective and highly varied. Accordingly, increases in the evenness and connection of dominant species induced by high resource diversity significantly contributed to plant disease suppression. Furthermore, high carbohydrate diversity upregulated plant immune system regulation-related microbial functions. Our results deepen the biodiversity-invasion resistance theory and provide practical guidance for the control of plant pathogens and diseases by using organic resource-mediated approaches, such as crop rotation, intercropping, and organic amendments.

Facilitating effects of the reductive soil disinfestation process combined with Paenibacillus sp. amendment on soil health and physiological properties of Momordica charantia

Reductive soil disinfestation (RSD) is an anaerobic and facultative anaerobic microbial-mediated soil management process. The extent of improvement of diseased soil properties by RSD relative to comparable healthy soil is, however, not well characterized. Importantly, how to promote the colonization efficiency of these facultative anaerobic functional species to ensure soil and plant health remain unknown. Here, Fusarium wilt-diseased soil of Momordica charantia grown under a plastic-shed field (PS-CK) was used to conduct molasses-RSD (MO-RSD) along with Paenibacillus sp. (a model of facultative anaerobic species) (MO_PA-RSD) treatment, and the soil from a nearby open-air paddy field was considered comparable healthy soil (OA-CK). Both RSD treatments significantly improved the properties of PS-CK soil, and the extent of improvement of soil pH, Fusarium oxysporum reduction efficiency (98.36%~99.56%), and microbial community and functional composition were higher than that achieved for OA-CK soil, which indicated that RSD-regulated most soil properties outperformed those of the comparable healthy soil. The disease incidence and ascorbic acid content of M. charantia in MO-RSD- and MO_PA-RSD-treated soils were considerably decreased, while the weight and soluble protein contents were correspondingly increased, as compared to those of M. charantia in PS-CK soil. Specifically, the changes in these physiological properties of M. charantia in MO_PA-RSD soil performed well than that in MO-RSD soil. The relative abundances of Cohnella, Effusibacillus, Rummeliibacillus, Oxobacter, Thermicanus, and Penicillium enriched in both RSD-treated soils were positively correlated with Paenibacillus and negatively correlated with F. oxysporum population and disease incidence (P < 0.05). Notably, the relative abundances of these potential probiotics were considerably higher in MO_PA-RSD-treated soil than in MO-RSD alone-treated soil. These results show that the RSD process with inoculation of Paenibacillus sp. could promote the colonization of this species and simultaneously stimulate the proliferation of other probiotic consortia to further enhance soil health and plant disease resistance.

Water quality status response to multiple anthropogenic activities in urban river

Water quality evaluation and degrading factors identification are crucial for predicting water quality evolution trends in an urban river. However, under the coupling of multiple factors, these targets face great challenges. The water quality status response to multiple anthropogenic activities in an urban river was evaluated and predicted based on comprehensive assessment methods and random forest (RF) model. We found that the distribution of each physicochemical parameter exhibits an obvious spatial clustering. The mean pollution level and trophic status of the urban river are medium pollution (water quality index = 59.79; Nemerow's pollution index = 2.00) and light eutrophication (trophic level index = 57.30). The water quality status is sensitive to anthropogenic activities, showing the following order of TLI and NPI values: residential district > industrial district > agricultural district and downtown > suburbs > countryside. According to the redundancy analysis, constructed land (F = 15.90, p < 0.01) and domestic sewage (F = 14.20, p < 0.01) evinced as the crucial factors that aggravated the water quality pollution level. Based on the simulation results of the RF model (variation explained = 94.91%; R² = 0.978), improving domestic sewage treatment standards is the most effective measure to improve the water quality (increased by 40.3-49.3%) in residential and industrial districts. While in a suburban district, improving the domestic sewage collection rate has more effectively (23%) than those in the residential and industrial districts. Conclusively, reducing exogenous pollution input and improving domestic sewage treatment standards are vital to urban river restoration. Clinical trial registration Not applicable.

Effects of Reductive Soil Disinfestation Combined with Liquid-Readily Decomposable Compounds and Solid Plant Residues on the Bacterial Community and Functional Composition

Reductive soil disinfestation (RSD) incorporated with sole plant residues or liquid-readily decomposable compounds is an effective management strategy to improve soil health. However, the synthetic effects of RSD incorporated with liquid-readily decomposable compounds and solid plant residues on soil ecosystem services remain unclear. Field experiments were carried out to investigate the effects of untreated soil (CK), RSD incorporated with sawdust (SA), molasses (MO), and their combinations (SA + MO) on the bacterial community and functional composition. The results showed that RSD treatments significantly altered soil bacterial community structure compared to CK treatment. The bacterial community structure and composition in MO and SA + MO treatments were clustered compared to SA treatment. This was mainly attributed to the readily decomposable carbon sources in molasses having a stronger driving force to reshape the soil microbial community during the RSD process. Furthermore, the functional compositions, such as the disinfestation efficiency of F. oxysporum (96.4 - 99.1%), abundances of nitrogen functional genes, soil metabolic activity, and functional diversity, were significantly increased in all of the RSD treatments. The highest disinfestation efficiency and abundances of denitrification (nirS and nrfA) and nitrogen fixation (nifH) genes were observed in SA + MO treatment. Specifically, SA + MO treatment enriched more abundant beneficial genera, e.g., Oxobacter, Paenibacillus, Cohnella, Rummeliibacillus, and Streptomyces, which were significantly and positively linked to disinfestation efficiency, soil metabolic activity, and denitrification processes. Our results indicated that combining RSD practices with liquid-readily decomposable compounds and solid plant residues could effectively improve soil microbial community and functional composition.

Potential biomarkers in the fibrosis progression of nonalcoholic steatohepatitis (NASH)

PURPOSE

Fibrosis is the only histological feature reflecting the severity and prognosis of nonalcoholic steatohepatitis (NASH). We aim to explore novel genes associated with fibrosis progression in NASH.

METHODS

Two human RNA-seq datasets were downloaded from the public database. Weighted gene co-expression network analysis (WGCNA) was used to identify their co-expressed modules and further bioinformatics analysis was performed to identify hub genes within the modules. Finally, based on two single-cell RNA-seq datasets from mice and one microarray dataset from human, we further observed the expression of hub genes in different cell clusters and liver tissues.

RESULTS

7 hub genes (SPP1, PROM1, SOX9, EPCAM, THY1, CD34 and MCAM) associated with fibrosis progression were identified. Single-cell RNA-seq analysis revealed that those hub genes were expressed by different cell clusters such as cholangiocytes, natural killer (NK) cells, and hepatic stellate cells (HSCs). We also found that SPP1 and CD34 serve as markers of different HSCs clusters, which are associated with inflammatory response and fibrogenesis, respectively. Further study suggested that SPP1, SOX9, MCAM and THY1 might be related to NASH-associated hepatocellular carcinoma (HCC). Receiver operating characteristic (ROC) analysis showed that the high expression of these genes could well predict the occurrence of HCC. At the same time, there were significant differences in metabolism-related pathway changes between different HCC subtypes, and SOX9 may be involved in these changes.

CONCLUSIONS

The present study identified novel genes associated with NASH fibrosis and explored their effects on fibrosis from a single-cell perspective that might provide new ideas for the early diagnosis, monitoring, evaluation, and prediction of fibrosis progression in NASH.

Soil dissolved organic matters mediate bacterial taxa to enhance nitrification rates under wheat cultivation

Studies have shown that dissolved organic matters (DOMs) may affect soil nutrient availability to plants due to their effect on microbial communities; however, the relationships of soil DOM-bacterial community-N function in response to root exudates remains poorly understand. Here, we evaluated the DOM composition, bacterial taxonomic variation and nitrogen transformation rates in both acidic and alkaline soils, with or without the typical nitrate preference plant (wheat, Triticum aestivum L.). After 30 days' cultivation, DOM compositions such as sugars, amines, amino acids, organic acid, and ketone were significantly increased in soil with wheat vs. bare soil, and these compounds were mainly involved in nitrogen metabolism pathways. Soil core bacterial abundance was changed while bacterial community diversity decreased in response to wheat planting. Function prediction analysis based on FAPROTAX software showed that the bacterial community were significantly (p < 0.05) affiliated with nitrification and organic compound degradation. Additionally, db-RDA and VPA analysis suggested that the contribution of soil DOM to the variance of bacterial community was stronger than that of soil available nutrients. Furthermore, the N-transformation related bacteria like Burkholderiales and ammonia-oxidizing bacteria (AOB) were positively correlated with soil gross nitrification rate, confirming that the soil N transformation was enhanced in both acidic and alkaline soils. Our results provide insight into how soil DOM affects the community structure and function of bacteria to regulate the process of nitrogen transformation in plant-soil system.

The influences of soil sulfate content on the transformations of nitrate and sulfate during the reductive soil disinfestation (RSD) process

The transformations and products of sulfate (SO₄^2-) and nitrate (NO₃^-), especially the influences of SO₄^2- content on the transformations during RSD process, are unclear. In this study, a series of soil SO₄^2- contents (from 333 to 3000 mg S kg^-1) were prepared before RSD treatment. The results indicated that nearly all the cumulative NO₃^- (>98.6%) was removed and not affected by the soil SO₄^2- content. The ¹⁵N recovery results showed that 0.57-1.24% and 2.94-4.59% of NO₃^- translated into ammonium (NH₄⁺) and organic N, respectively, and high SO₄^2- contents stimulated the processes of NO₃^- dissimilatory reduction and NO₃^- immobilization. The soluble SO₄^2- contents decreased by 397-922 mg S kg^-1, but the contents of total sulfur, sulfide, and sulfate precipitation varied slightly after RSD, indicating that the decreased SO₄^2- was mainly immobilized into organic sulfur in all soils. In addition, a fraction of decreased SO₄^2- was adsorbed to the soil with a relatively high SO₄^2- content. The leaching of SO₄^2- was high (42.9-602 mg S kg^-1) during the RSD process, and the leaching amounts increased with increasing soil SO₄^2- content. In terms of the gases emitted from the transformations of NO₃^- and SO₄^2-, the cumulative emissions of nitrous oxide (N₂O) and six sulfurous gases (hydrogen sulfide, carbonyl sulfide, carbon disulfide, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide) were in the ranges of 17.1-21.2 mg N kg^-1 and 7.78-23.5 μg S kg^-1, respectively, during the whole RSD process. The emissions of sulfurous gases were inhibited by high soil SO₄^2- content, but the N₂O emissions were unaffected. In conclusion, the soil SO₄^2- content influenced the transformations of NO₃^- and SO₄^2- during RSD process, and the SO₄^2- leaching and N₂O emissions might threaten the environment which should be concerned.

Cover Plants-Mediated Suppression of Fusarium Wilt and Root-Knot Incidence of Cucumber is Associated With the Changes of Rhizosphere Fungal Microbiome Structure-Under Plastic Shed System of North China

Cover crops are known to alleviate the adverse effects of continuous cropping by influencing plant health and changing host fungal-microbiome structures. However, insight into the shift of rhizomicrobiota composition and their effects on plant growth performance and resistance mechanism is still limited under plastic shed cultivation (PSC). Four leafy vegetable rotations namely spinach rotation (SR), non-heading Chinese cabbage rotation (NCCR), coriander rotation (CR), and leafy lettuce rotation (LLR) were used as cover crops in 7-years of continuous cucumber planted soil (CC). Their ecological impacts were studied for plant growth performance, replant diseases incidence rate, and rhizosphere fungal microbiome. Compared to CC, SR showed a highly suppressive effect on fusarium wilt, i.e., by 13.2% in the spring season, while NCCR decreased the root-knot nematode incidence rate by 8.9% in the autumn season. Such protective effects caused a significant increase of shoot and fruit biomass and thus sustained the fruit quality of cucumber. High-throughput sequencing revealed that the CR, SR, and NCCR treatments altered the fungal community composition by increasing the abundance of the beneficial fungal genera, decreasing pathogenic taxa, and fostering the saprotrophic and symbiotic functions. However, the relative abundance of most of the potentially pathogenic fungal genera increased in CC and LLR cropping. There were 8 potential pathogens and 10 beneficial or biocontrol fungi characterized. It was found that Paecilomyces, Chaetomium, Cladorrhinum, Zopfiella, Purpureocillium, and Metarhizium were the putative biocontrol microbes that positively affected plant growth and replanted diseases inhibition. The characterized Fusarium, Dactylonectria, Alternaria, Gibberella, and Aspergillus were the key pathogenic fungal agents found to be negatively associated with plant growth characters, suggesting that rhizomicrobiome may play an important role in the occurrence of disease incidence of cucumber plants. Considering the ecological potential of some cover plants, this study suggested that rotation with spinach, non-heading Chinese cabbage, or coriander can enhance rhizosphere immunity by triggering the development of plant-protective fungal microbiomes under plastic shed cucumber cultivation.

Global Patterns and Drivers of Soil Dissimilatory Nitrate Reduction to Ammonium

Dissimilatory nitrate reduction to ammonium (DNRA), the nearly forgotten process in the terrestrial nitrogen (N) cycle, can conserve N by converting the mobile nitrate into non-mobile ammonium avoiding nitrate losses via denitrification, leaching, and runoff. However, global patterns and controlling factors of soil DNRA are still only rudimentarily known. By a meta-analysis of 231 observations from 85 published studies across terrestrial ecosystems, we find a global mean DNRA rate of 0.31 ± 0.05 mg N kg^-1 day^-1, being significantly greater in paddy soils (1.30 ± 0.59) than in forests (0.24 ± 0.03), grasslands (0.52 ± 0.15), and unfertilized croplands (0.18 ± 0.04). Soil DNRA was significantly enhanced at higher altitude and lower latitude. Soil DNRA was positively correlated with precipitation, temperature, pH, soil total carbon, and soil total N. Precipitation was the main stimulator for soil DNRA. Total carbon and pH were also important factors, but their effects were ecosystem-specific as total carbon stimulates DNRA in forest soils, whereas pH stimulates DNRA in unfertilized croplands and paddy soils. Higher temperatures inhibit soil DNRA via decreasing total carbon. Moreover, nitrous oxide (N₂O) emissions were negatively related to soil DNRA. Thus, future changes in climate and land-use may interact with management practices that alter soil substrate availability and/or soil pH to enhance soil DNRA with positive effects on N conservation and lower N₂O emissions.

[Heparin-binding hemagglutinin as a composition antigen of tuberculosis vaccine exerts protective immune effects by inducing IL-17]

To explore the protective immune effect induced by mucosal delivery heparin-binding hemagglutinin (HBHA)-a candidate vaccine antigen of Mycobacterium tuberculosis. Female C57BL/6 mice were between 6 and 8 weeks of age before experimental use. Thirty mice received different immunization strategies and were randomly divided into the control group, the early secreting antigen target-6 (ESAT-6) intranasal immunization group, the HBHA intranasal immunization group, the BCG priming PBS control group, or BCG priming HBHA boost group, 6 mice in each group. In order to analyzed the immune effect, the concentrations of plasma Interleukin-17A (IL-17A) and other cytokines were measured by ELISA. Quantitative real-time PCR analyses were performed to detect the relative quantity (RQ) mRNA of IL-17A in the lung. The lung tissue sections were stained to detect the formation of the tertiary lymphoid structures. The chemokines contributed to formation of the tertiary lymphoid structures were also measured. Flow cytometry was used to detect the frequency of Th1 and Th17 cells in the system. Sixty mice in the BCG priming PBS control group and the BCG priming HBHA boost group were sacrificed at different time points after infection to count the lung bacterial burden. The concentrations of plasma IL-17A and relative quantity of lung IL-17A mRNA were highest in the BCG priming HBHA boost group [(14.76±4.73) pg/mL,RQ (12.27±6.71)], which was significantly higher than the control group [(5.57±2.95) pg/mL,RQ (1.30±0.97)] (t=4.213, P<0.001; t=5.984, P<0.001), and also significantly higher than the BCG priming PBS control group [(6.81±2.18) pg/mL,RQ (1.44±1.16)] (t=3.646 P=0.001; t=6.185 P<0.001). Compared with the BCG priming PBS control group (0.38±0.38)% the frequency of spleen Th17 cells were also significantly increased (t=-0.280, P=0.048) in the BCG-primary HBHA boost group (1.02±0.34)%. In addition, HBHA boosting could promote better formation of the tertiary lymphoid structures in the lung, and decrease the bacterial load on the early stage after BCG challenge. Collectively, mucosal delivery of HBHA can effectively enhance the protective effect after BCG vaccination, and it is a potential candidate vaccine component.

Comparative Microbial Nitrogen Functional Gene Abundances in the Topsoil vs. Subsoil of Three Grassland Habitats in Northern China

The microbial groups of nitrogen fixers, ammonia oxidizers, and denitrifiers play vital roles in driving the nitrogen cycle in grassland ecosystems. However, the understanding of the abundance and distribution of these functional microorganisms as well as their driving factors were limited mainly to topsoil. In this study, the abundances of nitrogen functional genes (NFGs) involved in nitrogen fixation (nifH), ammonia oxidation (amoA), and denitrification (nirK, nirS, and nosZ) were investigated in both topsoil (0-10 cm, soil layer with concentrated root) and subsoil (30-40 cm, soil layer with spare root) of three grassland habitats in northern China. The abundance of NFGs decreased with soil depth except for the archaeal amoA gene and the distribution of nifH, archaeal amoA, nirK, and nirS gene was significantly impacted by grassland habitats. Moreover, the distribution of NFGs was more responsive to the vertical difference than horizontal spatial heterogeneity. Redundancy analysis revealed that the distribution pattern of overall NFGs was regulated by grassland habitats, and these regulations were more obvious in the subsoil than in the topsoil. Variance partitioning analysis further indicated that soil resource supply (e.g., organic matter) may control the vertical distribution of NFGs. Taken together, the findings in this study could fundamentally improve our understanding of the distribution of N cycling-associated microorganisms across a vertical scale, which would be useful for predicting the soil N availability and guiding the soil N management in grassland ecosystems.

What is an appropriate caesarean delivery rate for China: a multicentre survey

Objective

To assess the current status of caesarean delivery (CD) in China, propose reference CD rates for China overall, and by regions, investigate the main indications for CDs and identify possible areas for safe reduction.

Design

A multicentre cross‐sectional study.

Setting

A total of 94 hospitals across 23 provinces in China.

Population

A total of 73 977 randomly selected deliveries.

Methods

We used a modified Robson classification to characterise CDs in subgroups and by regions, and the World Health Organization (WHO) C‐Model to calculate reference CD rates.

Main outcome measures

CD rates in China.

Results

In 2015–2016, the overall CD rate in China was 38.9% (95% CI 38.6–39.3%). Considering the obstetric characteristics of the population, the multivariable model‐based reference CD rate was estimated at 28.5% (95% CI 28.3–28.8%). Accordingly, an absolute reduction of 10.4% (or 26.7% relative reduction) may be considered. The CD rate varied substantially by region. Previous CD was the most common indication in all regions, accounting for 38.2% of all CDs, followed by maternal request (9.8%), labour dystocia (8.3%), fetal distress (7.7%) and malpresentation (7.6%). Overall, 12.7% of women had prelabour CDs, contributing to 32.8% of the total CDs.

Conclusions

Nearly 39% of births were delivered by caesarean in China but a reduction of this rate by a quarter may be considered attainable. Repeat CD contributed more than one‐third of the total CDs. Given the large variation in maternal characteristics, region‐specific or even hospital‐specific reference CD rates are needed for precision management of CD.

Tweetable abstract

The caesarean rate in 2015–2016 in China was 38.9%, whereas the reference rate was 28.5%.

The caesarean rate in 2015–2016 in China was 38.9%, whereas the reference rate was 28.5%.

Linked article This article is commented on by M Varner, p. 148 in this issue. To view this mini commentary visit https://doi.org/10.1111/1471-0528.16953.

Nitrogen cascade in the agriculture-food-environment system of the Yangtze Delta, 1998-2018

The nitrogen (N) cascade in rural areas of Changshu County should be measured and evaluated due to the large increase in anthropogenic disturbances in China's Yangtze Delta. Here, we developed a village-scale N flow model using Changshu County and its towns as a case study. The model included four subsystems and was used to describe the driving forces behind the N cascade from agricultural food production and household consumption to the environment (agriculture-food-environment) system. It was found that from 1998 to 2018 the N input increased from 274.63 to 848.65 kg N ha^-1. The cropland N use efficiency (NUEc) decreased by 10.35%, whereas the livestock feed N use efficiency (NUEa) increased by 51.84%. A relatively lower NUE, with a higher N input, was found in Shajiabang Town, which was attributed to hairy crab farming. Changes in dietary patterns led to the food N cost (FNC) being in the range of 4.59-7.74 kg kg^-1. Over the past two decades, the N losses from the agriculture-food-environment system decreased by 45.40% from 12,436.60 t N yr^-1 (1998). The contribution of the croplands, livestock-breeding, and household consumption to the N losses were 32.44%, 37.78%, and 29.78%, respectively. About 62.83% of the total N losses entered the water environment. Nitrogen emissions from the croplands accounted for 63.21% of the N losses into the atmosphere. Nitrogen oxide (NO_x) emissions accounted for 38.50% of the gas emissions, followed by NH₃ (28.36%) and N₂O (2.81%). The total N losses decreased annually but losses to the water environment increased by 5.10% from 60.16% (1998). The contribution of food production to the total N loss displayed a decreasing trend, while that of food consumption exhibited an increasing trend. Population growth and increased volumes of domestic waste in the Changsu area were the main driving forces for the increased contribution of household food consumption. The significant decline in cropland area and increase in built-up and heavily trafficked areas indicated an overall increase in anthropogenic disturbances, stimulating the N cascade in the Yangtze Delta from 1998 to 2018.

Microbial process-oriented understanding of stimulation of soil N2O emission following the input of organic materials

Although crop residue return increases upland soil emissions of nitrous oxide (N₂O), a potent greenhouse gas, the mechanisms responsible for the increase remain unclear. Here, we investigate N₂O emission pathways, gross nitrogen (N)-cycling rates, and associated N-cycling gene abundances in an upland soil following the addition of various organic material under aerobic incubation using a combination of ¹⁵N tracing technique, acetylene (C₂H₂) inhibition, and real-time PCR (qPCR) methods. Increased total N₂O emissions following organic material amendment was attributed to both increased nitrification-derived N₂O emissions, following increased ammonia-oxidizing bacteria (AOB)-amoA abundance, and denitrification-derived N₂O emissions, following increased nirS and decreased nosZ abundance. Increasing plant residue carbon (C)/N ratio decreased total N₂O emissions by decreasing the contribution of denitrification to N₂O emissions, potentially due to higher proportions of denitrified N emitted as N₂O than nitrified N emitted as N₂O. We further propose a novel conceptual framework for organic material input effects on denitrification-derived N₂O emissions based on the decomposable characteristics of the added organic material. For slowly decomposing organic materials (e.g., plant residue) with insufficient available C, NO₃^--N immobilization surpassed denitrification, resulting in gradual decrease in denitrification-derived N₂O emissions with an increase in mineralization of plant residue C losses. In contrast, available C provided by readily available C sources (e.g., glucose) seemed sufficient to support the co-occurrence of NO₃^--N immobilization and denitrification. Overall, for the first time, we offer a microbial process perspective of N₂O emissions following organic material input. The findings could facilitate the improvement of process-orientated models of N₂O emissions and the formulation of appropriate N₂O mitigation strategies for crop residue-amended soils.

[Choices of emergency treatment and surgical method for ruptured abdominal aortic aneurysms]

Objective: To investigate the emergency management process of ruptured abdominal aortic aneurysm (RAAA), and analyze the perioperative mortality factors of different surgical methods. Methods: The emergency data and hospitalization data of 91 patients with ruptured abdominal aortic aneurysm in Xiangya Hospital of Central South University from June 2010 to June 2019 were retrospectively analyzed.Twelve of the patients died preoperatively due to excessive blood loss, and the remaining 79 patients were hospitalized for open surgery (OSR) or endovascular repair (EVAR).The differences in age, time to hospital arrival, emergency preparation time, first creatinine value, emergency infusion volume, preoperative drop in blood pressure, preoperative use of vasoactive drugs and iliac artery involvement were compared between preoperative death group (n=12) and preoperative survival group (n=79), OSR group (n=50) and EVAR group (n=29), postoperative death group (n=23) and postoperative survival group (n=56). Results: Seventy-nine patients received open surgery or endovascular repair, and 23 died after operation. Age, time to hospital arrival, first creatinine value and emergency infusion volume were (77±11) years, (18±5)h, (469±150) μmol/L, (4 140±1 743) ml in the preoperative death group and (70±10) years, (12±8) h, (228±174) μmol/L, (1 358±1 211) ml in the preoperative survival group, respectively, and the differences were statistically significant (all P<0.05). There were no significant differences in preoperative data, intraoperative treatment and postoperative perioperative mortality between the open surgery group and the endovascular repair group (all P>0.05). The intraoperative blood loss, operation time and aortic occlusion rate in the endovascular repair group were 100 (50, 175) ml, (3.2±0.9) h, 13.8%, respectively, which were better than that in the open surgery group 1700 (600, 3425) ml, (5.2±1.1) h, 100%. The differences were statistically significant (all P<0.05). Age, emergency preparation time, first creatinine value, emergency infusion volume, blood pressure decline rate and vasoactive drug utilization rate in the death group were (77±8) years, (4.1±1.7) h, (456±172) μmol/L, (2 024±1 687) ml, 100%, 100%, respectively, and (68±10) years, (2.7±2.2) h, (135±26) μmol/L, (1 085±825) ml, 21.4%, 12.5% in the survival group, respectively. The differences were statistically significant (all P<0.05). Conclusions: Age, emergency preparation time, first creatinine value, emergency infusion volume, decreased blood pressure and use of vasoactive drugs are all associated with perioperative death in patients with ruptured abdominal aortic aneurysm. EVAR surgery is a better choice if conditions exist.

The complex multi-sectoral impacts of drought: Evidence from a mountainous basin in the Central Spanish Pyrenees

We analyzed the impacts of drought severity on a variety of sectors in a topographically complex basin (the upper Aragón basin 2181 km²) in the Central Spanish Pyrenees. Using diverse data sources including meteorological and hydrological observations, remote sensing and tree rings, we analyze the possible hydrological implications of drought occurrence and severity on water availability in various sectors, including downstream impacts on irrigation water supply for crop production. Results suggest varying responses in forest activity, secondary growth, plant phenology, and crop yield to drought impacts. Specifically, meteorological droughts have distinct impacts downstream, mainly due to water partitioning between streamflow and irrigation channels that transport water to crop producing areas. This implies that drought severity can extend beyond the physical boundaries of the basin, with impacts on crop productivity. This complex response to drought impacts makes it difficult to develop objective basin-scale operational definitions for monitoring drought severity. Moreover, given the high spatial variability in responses to drought across sectors, it is difficult to establish reliable drought thresholds from indices that are relevant across all socio-economic sectors. The anthropogenic impacts (e.g. water regulation projects, ecosystem services, land cover and land use changes) pose further challenges to assessing the response of different systems to drought severity. This study stresses the need to consider the seasonality of drought impacts and appropriate drought time scales to adequately assess and understand their complexity.

Can N Fertilizer Addition Affect N2O Isotopocule Signatures for Soil N2O Source Partitioning?

Isotopocule signatures of N₂O (δ¹⁵N^bulk, δ¹⁸O and site preference) are useful for discerning soil N₂O source, but sometimes, N fertilizer is needed to ensure that there is enough N₂O flux for accurate isotopocule measurements. However, whether fertilizer affects these measurements is unknown. This study evaluated a gradient of NH₄NO₃ addition on N₂O productions and isotopocule values in two acidic subtropical soils. The results showed that N₂O production rates obviously amplified with increasing NH₄NO₃ (p < 0.01), although a lower N₂O production rate and an increasing extent appeared in forest soil. The δ¹⁵N^bulk of N₂O produced in forest soil was progressively enriched when more NH₄NO₃ was added, while becoming more depleted of agricultural soil. Moreover, the N₂O site preference (SP) values collectively elevated with increasing NH₄NO₃ in both soils, indicating that N₂O contributions changed. The increased N₂O production in agricultural soil was predominantly due to the added NH₄NO₃ via autotrophic nitrification and fungal denitrification (beyond 50%), which significantly increased with added NH₄NO₃, whereas soil organic nitrogen contributed most to N₂O production in forest soil, probably via heterotrophic nitrification. Lacking the characteristic SP of heterotrophic nitrification, its N₂O contribution change cannot be accurately identified yet. Overall, N fertilizer should be applied strictly according to the field application rate or N deposition amount when using isotopocule signatures to estimate soil N₂O processes.

Ulinastatin improves myocardial ischemia-reperfusion injury in rats through endoplasmic reticulum stress-induced apoptosis pathway

OBJECTIVE

To investigate the protective role of ulinastatin (UTI) on myocardial ischemia-reperfusion (I/R) injury in rats via endoplasmic reticulum stress (ERS)-induced apoptosis pathway.

MATERIALS AND METHODS

A total of 60 rats were randomly divided into normal group (n=20), myocardial I/R model group (model group, n=20), and myocardial I/R model+UTI treatment group (treatment group, n=20). The myocardial function indicators [creatinine (Scr) and creatine kinase (CK)] were detected. Enzyme-linked immunosorbent assay (ELISA) was performed to measure serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and matrix metalloproteinase-9 (MMP-9). Meanwhile, the contents of reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) in rat left ventricular tissues were determined by ELISA as well. The cardiac function indexes were determined via magnetic resonance imaging (MRI) and echocardiography (ECG). Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining assay was carried out to detect the apoptosis of myocardial tissues. Additionally, the expression levels of endoplasmic reticulum stress and apoptosis genes were measured through quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) assay and Western blotting analysis, respectively.

RESULTS

Serum levels of alanine aminotransferase (ALT), CK, and Scr in model group were significantly higher than those in normal group (p<0.05). Besides, rats in model group had significantly lowered SOD, ejection fraction (EF, %), and fractional shortening (FS, %) than those in normal group (p<0.05). In addition, remarkably increased contents of TNF-α, IL-6, MMP-9, MDA, and ROS, as well as higher left ventricular end-diastolic diameter (LVEDd) and left ventricular end-systolic diameter (LVESd) were observed in model group in comparison with normal group (p<0.05). TUNEL staining results revealed that there were more apoptotic cells in model group than that in the other two groups (p<0.05). Expression levels of cysteine aspartic acid-specific protease 12 (Caspase-12) and glucose-regulated protein 78 (GRP78) were evidently higher in model group than those in normal group (p<0.05), while the expression level of B-cell lymphoma 2 (Bcl-2) was clearly lower in model group than that in normal group (p<0.05). UTI treatment partially reversed the above expression changes (p<0.05).

CONCLUSIONS

UTI has a protective effect against myocardial I/R injury in rats by repressing the occurrence of ERS-induced apoptosis.

Liquid biopsy by combining 5-hydroxymethylcytosine signatures of plasma cell-free DNA and protein biomarkers for diagnosis and prognosis of hepatocellular carcinoma

BACKGROUND

Liquid biopsy based on 5-hydroxymethylcytosine (5hmC) signatures of plasma cell-free DNA (cfDNA) originating from tumor cells provides a novel approach for early diagnosis in hepatocellular carcinoma (HCC). Here, we sought to develop a reliable model using cfDNA 5hmC signatures and protein biomarkers for diagnosis and prognosis of HCC.

PATIENTS AND METHODS

We carried out genome-wide 5hmC sequencing of cfDNA samples collected from 165 healthy volunteers, 62 liver cirrhosis (LC) patients and 135 HCC patients. A sensitive 5hmC diagnostic model was developed based on 5hmC signatures selected by sparse Partial Least Squares Discriminant Analysis and cross-validation to define the weighted diagnostic score (wd-score). Then, we combined protein biomarkers with the wd-score to build a more robust score (HCC score) by logistic regression.

RESULTS

The distribution pattern of differential 5hmC regions could clearly distinguish HCC patients, LC patients and healthy volunteers. The wd-score based on 64 5hmC signatures in cfDNA achieves 93.24% of area under the curve (AUC) to distinguish HCC patients from non-HCC patients, and the HCC score by combing protein biomarkers achieves 92.75% of AUC to distinguish HCC patients from LC patients. Meanwhile, the HCC score showed high capacity for screening high recurrence risk patients after receiving surgical resection, and appeared to be an independent indicator for both relapse-free survival (P = 0.00865) and overall survival (P = 0.000739). Furthermore, the values of the HCC score in patients' longitudinal plasma samples were positively associated with tumor burden dynamics during follow-up.

CONCLUSION

We have developed and validated a novel non-invasive liquid biopsy strategy for HCC diagnosis, prognosis and surveillance during HCC progression.

[The effect of peripheral blood cell score on the prognosis of multiple myeloma patients treated with bortezomib]

目的

评估外周血细胞检测结果在以硼替佐米为一线治疗的多发性骨髓瘤（MM）患者中的预后作用。

方法

回顾性分析2014年1月至2016年12月浙江大学医学院附属第一医院和浙江省舟山医院收治的155例初诊MM患者的临床数据，患者均一线接受以硼替佐米为基础方案的治疗。分析外周血细胞检测结果，包括ANC、单核细胞计数（AMC）、HGB、红细胞平均体积（MCV）、PLT以及其他临床特征对MM患者的预后评估作用。

结果

AMC（>0.6×10⁹/L）、MCV（>99.1fl）以及PLT（<150×10⁹/L）明显影响MM患者无进展生存（PFS）和总生存（OS），以上3个因子分别赋值1分，形成血细胞积分。结果显示，64例（41.3％）积分0，57例（36.8％）积分1，32例（20.6％）积分2，2例（1.3％）积分3，4组患者中位PFS时间分别为42.8、26.5、15.8、6.4个月（P<0.001），中位OS时间分别为未达到和48.2、31.1、31.4个月（P＝0.001）。多因素分析提示，血细胞积分（2～3对0～1）和骨髓浆细胞比例（>30％对≤30％）为PFS的独立预后因素（HR分别为1.95和1.76），而患者年龄（>65岁对≤65岁）、R-ISS分期（Ⅲ期对Ⅰ～Ⅱ期）和血细胞积分（2～3对0～1）是OS的独立预后因素（HR分别为2.08、2.13和2.12）。

结论

血细胞积分简单易得，可用于新药时代初治MM患者的预后评估，但仍需扩大病例并进行前瞻性研究进一步明确。

Soil gross nitrogen transformations in forestland and cropland of Regosols

Soil gross nitrogen (N) transformations could be influenced by land use change, however, the differences in inherent N transformations between different land use soils are still not well understood under subtropical conditions. In this study, an ¹⁵N tracing experiment was applied to determine the influence of land uses on gross N transformations in Regosols, widely distributed soils in Southwest China. Soil samples were taken from the dominant land use types of forestland and cropland. In the cropland soils, the gross autotrophic nitrification rates (mean 14.54 ± 1.66 mg N kg^-1 day^-1) were significantly higher, while the gross NH₄⁺ immobilization rates (mean 0.34 ± 0.10 mg N kg^-1 day^-1) were significantly lower than those in the forestland soils (mean 1.99 ± 0.56 and 6.67 ± 0.74 mg N kg^-1 day^-1, respectively). The gross NO₃^- immobilization and dissimilatory NO₃^- reduction to NH₄⁺ (DNRA) rates were not significantly different between the forestland and cropland soils. In comparison to the forestland soils (mean 0.51 ± 0.24), the cropland soils had significantly lower NO₃^- retention capacities (mean 0.01 ± 0.01), indicating that the potential N losses in the cropland soils were higher. The correlation analysis demonstrated that soil gross autotrophic nitrification rate was negatively and gross NH₄⁺ immobilization rate was positively related to the SOC content and C/N ratio. Therefore, effective measures should be taken to increase soil SOC content and C/N ratio to enhance soil N immobilization ability and NO₃^- retention capacity and thus reduce NO₃^- losses from the Regosols.

Toward High Precision XCO2 Retrievals From TanSat Observations: Retrieval Improvement and Validation Against TCCON Measurements

TanSat is the 1st Chinese carbon dioxide (CO2) measurement satellite, launched in 2016. In this study, the University of Leicester Full Physics (UoL-FP) algorithm is implemented for TanSat nadir mode XCO2 retrievals. We develop a spectrum correction method to reduce the retrieval errors by the online fitting of an 8th order Fourier series. The spectrum-correction model and its a priori parameters are developed by analyzing the solar calibration measurement. This correction provides a significant improvement to the O2 A band retrieval. Accordingly, we extend the previous TanSat single CO2 weak band retrieval to a combined O2 A and CO2 weak band retrieval. A Genetic Algorithm (GA) has been applied to determine the threshold values of post-screening filters. In total, 18.3% of the retrieved data is identified as high quality compared to the original measurements. The same quality control parameters have been used in a footprint independent multiple linear regression bias correction due to the strong correlation with the XCO2 retrieval error. Twenty sites of the Total Column Carbon Observing Network (TCCON) have been selected to validate our new approach for the TanSat XCO2 retrieval. We show that our new approach produces a significant improvement on the XCO2 retrieval accuracy and precision when compared to TCCON with an average bias and RMSE of -0.08 ppm and 1.47 ppm, respectively. The methods used in this study can help to improve the XCO2 retrieval from TanSat and subsequently the Level-2 data production, and hence will be applied in the TanSat operational XCO2 processing.

Lower plasma melatonin levels predict worse long-term survival in pulmonary arterial hypertension

Background

Exogenous melatonin has been reported to be beneficial in the treatment of pulmonary hypertension (PH) in animal models. Multiple mechanisms may be involved, with melatonin exerting anti-oxidant and anti-inflammatory effects, as well as inducing vasodilation and cardio-protection. However, endogenous levels of melatonin in treatment-naïve pulmonary arterial hypertension (PAH) patients and their clinical significance are still unknown.

Methods and results

Plasma levels of endogenous melatonin were measured by liquid chromatography-tandem mass spectrometry in treatment-naïve PAH patients (n=43) and healthy controls (n=111). Melatonin levels were higher in PAH patients when compared with controls (Median 118.9 [IQR 109.3–147.7] versus 108.0 [102.3–115.2] pM, P&lt;0.001) (Figure 1A). The overall mortality was 26% (11/43) during a median long-term follow-up of 42 [IQR: 32–58] months. When PAH patients were stratified into 4 groups according to the quartiles of melatonin levels, the mortality from below 1st quartile to above 4th quartile was 55% (6/11), 10% (1/10), 0% (0/12), and 40% (4/10), respectively (Figure 1B). Kaplan-Meier analysis further showed that patients with melatonin levels below the 1st quartile (&lt;109.3 pM) had a worse long-term survival than patients with melatonin levels above the 1st quartile (Mean survival times were 46 [95% CI: 30–65] versus 68 [58–77] months, Log-rank, p=0.026) (Figure 1C).

Conclusion

Endogenous melatonin levels were increased in treatment-naïve PAH patients, and lower levels of melatonin were associated with worse long-term survival in patient with PAH, however, whether exogenous melatonin supplements may be effective as a therapeutic strategy in human PAH remains to be established.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This work was supported by the China Scholarship Council (201606230252) as well as the Netherlands CardioVascular Research Initiative: an initiative with support of the Dutch Heart Foundation (CVON2014-11, RECONNECT), and German Center for Cardiovascular Research (DZHK81Z0600207). Instrumentation support was received from AB Sciex, ltd. for LC-MS/MS analyses performed in this study.

Different tryptophan-kynurenine metabolism profiles in human pulmonary arterial hypertension and animal models of pulmonary hypertension

Background

De novo NAD+ synthesis through the tryptophan-kynurenine (TK) metabolism was recognized as an important pathway in improving mitochondrial function and survival of injury or apoptotic cells, which are key processes involved in the pathogenesis of pulmonary arterial hypertension (PAH). Although abnormal TK metabolism has been reported in human PAH, the difference between human and animal models of pulmonary hypertension (PH) are currently unknown.

Objective

Determine and compare TK metabolism profiles in plasma from human PAH and 3 animal models of PH.

Methods

Human plasma was collected from treatment naïve patients with PAH (n=43) and healthy controls (n=111). Animal plasma was collected from 3 animal models of PH and corresponding controls, including monocrotaline (MCT) induced PH in rat (n=7, control n=6), Sugen + hypoxia (SuHx) induced PH in rat (n=5, control n=6), and pulmonary vein banding (PVB) induced PH in swine (n=7, control n=6). TK metabolites were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results

TK metabolism was altered in the plasma from of PAH compared to healthy controls (Figure 1A). Lower tryptophan (0.8 fold vs Control, p&lt;0.0001), maintained 3-hydroxyanthranilic acid, and higher kynurenine, 3-hydroxykynurenine, anthranilic acid, and quinolinic acid (1.5, 2.6, 2.0, 2.6 fold vs Control, respectively, p all&lt;0.0001) were seen in the plasma from human PAH. In the rat SuHx-PH model, kynurenine (0.7 fold, p&lt;0.01) and quinolinic acid (0.5 fold, p&lt;0.001) were lower, while 3-hydroxyanthranilic acid (4.3 fold, p&lt;0.001) was higher in PH compared to control (Figure 1B). However, the TK metabolism was unaltered in MCT-PH model in rat (Figure 1C), and PVB-PH model in swine (Figure 1D).

Conclusions

TK metabolism was altered in the plasma from human PAH. The TK metabolism profiles were different among 3 animal models of PH, but did not mimic the profile in human PAH. Further research is required to determine the mechanism(s) behind the abnormal TK metabolism in human PAH as well as whether these mechanisms relate to disease onset or progression.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This work was supported by the China Scholarship Council (201606230252) as well as the Netherlands CardioVascular Research Initiative: an initiative with support of the Dutch Heart Foundation (CVON2014-11, RECONNECT), and German Center for Cardiovascular Research (DZHK81Z0600207). Instrumentation support was received from AB Sciex, ltd. for LC-MS/MS analyses performed in this study.