Explore the vast range of titles available.

We investigated soil bacterial and fungal communities, constructed co‐occurrence networks, and estimated bacterial traits along a gradient of nitrogen (N) input. The results showed that soil bacterial co‐occurrence networks complexity decreased with increasing N input. The ratio of negative to positive cohesion decreased with increasing N input, suggesting the declined competitive but strengthened cooperative interactions. However, soil fungal network complexity did not change under N enrichment. In addition, N input stimulated the copiotroph/oligotroph ratio, ribosomal RNA operon (rrn) copy number, and guanine‐cytosine (GC) content of soil bacteria, shifting bacterial life history strategy toward copiotroph with increased r‐/K‐strategy ratio. Piecewise structural equation modeling results further revealed that the reduction in bacterial co‐occurrence network complexity was directly regulated by the increased bacterial r‐/K‐strategy ratio, rather than reduced bacterial richness. Our study reveals the mechanisms through which microbial traits regulate interactions and shape co‐occurrence networks under global changes.

Ballastless track continuous welded rails (CWR) are used on a multi-span 100 m simply supported steel truss bridge of a mixed passenger and freight railway, to study the mechanical characteristics and influence factors of CWR on the 100 m simply supported steel truss bridge, a track-bridge-piers spatial finite element model was established based on the track-bridge interaction (TBI) principle. The influence of design parameters such as the number of bridge spans, the longitudinal stiffness of piers of the simply supported steel truss bridge, the arrangement of bridge bearings, the type of rail, and the track longitudinal resistance type on the mechanical characteristics of CWR on the simply supported steel truss bridge were systematically examined. The research results indicate that for multi-span simply supported steel truss bridges, the model can be simplified by considering 8 spans when the total number of spans exceeds 8. Likewise, when the number of adjacent concrete box girder spans exceeds 5, 5 spans can be adopted. The longitudinal stiffness of piers of the simply supported steel truss bridge has a significant influence on the rail braking force and the rail broken gap. Increasing the longitudinal stiffness of the piers from 399kN/cm to 5000kN/cm has a much greater effect on the forces and deformations of CWR on the bridge than increasing it further from 5000kN/cm to 10000kN/cm. The bridge expansion length is primarily governed by the arrangement of fixed bearings on the adjacent concrete box girder. Therefore, to reduce the forces in the CWR on the bridge, the simply supported steel truss bridges and the adjacent concrete box girders should adopt a consistent bearing arrangement. In addition, rails with a larger cross-sectional area can reduce the additional rail stress. The used of small resistance fastener systems for ballastless track decreases the rail expansion force and rail braking force by 56.72% and 18.05%, respectively, but it increases the rail broken gap by 37.49%. The research results can provide references for the design of CWR on the simply supported steel truss bridge.

High temperature (HT) and drought stress (DS) play negative roles in wheat growth, and are two most important factors that limit grain yield. Starch, the main component of the wheat [][endosperm, accounts for 65–75% of grain weight, and is significantly influenced by environmental factors. To understand the effects of post-anthesis HT and DS on starch biosynthesis, we performed a pot experiment using wheat cultivar “Zhengmai 366” under field conditions combined with a climate-controlled greenhouse to simulate HT. There were two temperature regimes (optimum day/night temperatures of 25/15°C and high day/night temperatures of 32/22°C from 10 days after anthesis to maturity) accompanied by two water treatments (optimum of ∼75% relative soil water content, and a DS of ∼50% relative soil water content). Optimum temperature with optimum water treatment was the control (CK). We evaluated the expression patterns of 23 genes encoding six classes of enzymes involved in starch biosynthesis in wheat grains using real-time qPCR. HT, DS, and HT+DS treatments altered gene expression profiles. Compared to the CK, expression of 22 of the 23 genes was down regulated by HT, and only one gene ( ISA2 ) was up-regulated by HT. Actually ISA2 was the only gene up-regulated by all three stress treatments. The expression of 17 genes was up-regulated, while six genes, including granule-bound starch synthase ( GBSSI ) , AGPS2 , BEIII, PHOL, ISA1 , and AGPL2 , were down-regulated by DS. Eleven genes were down-regulated and 12 were up-regulated by HT+DS. The activity of ADP-Glc pyrophosphorylase, starch synthases , GBSS, SS, and starch branching enzymes in the stress treatments (HT, DS, and HT+DS) often appeared to peak values in advance and declined significantly to be lower than that in the CK. The genes that coordinated participation in the enzymes formation can serve as an indicator of the enzymes activity potentially involved in starch biosynthesis. HT, DS, and HT+DS altered the timing of starch biosynthesis and also influenced the accumulation of amylose, amylopectin, total starch, and sucrose. Under HT, DS, and HT+DS, the key enzymes activity and their genes expression associated with the conversion of sucrose to starch, was reduced, which was the leading cause of the reductions in starch content. Our study provide further evidence about the effects of stress on starch biosynthesis in wheat, as well as a physiological understanding of the impact of post-anthesis heat and DS on starch accumulation and wheat grain yield.

Excessive nitrogen (N) application combined with water shortage has a negative effect on crop production, particularly wheat ( L.) production in the North China Plain. This study examined root growth and water and nitrogen use efficiencies in wheat grown on loam soil in the North China Plain, from 2012 to 2014 using a fixed-position experiment initiated in 2010. The experiment followed a completely randomized split-plot design with four replications, taking irrigation [no irrigation (W0) versus irrigation at jointing plus flowering (W2)] as the main plot and N treatment (0, 180, 240, and 300 kg N ha ) as the subplot. Compared with W0, W2 increased grain yield and root weight density (RWD) by up to 91.3 and 57.7% in 2012-2013, and 15.5 and 43.0% in 2013-2014, respectively, across all N application rates. Irrigation had no effect on grain water use efficiency (WUE ), but caused a decrease in biomass WUE at vegetative growth stage (WUE ) and at grain-filling stage (WUE ). Significant improvements in grain yield and biomass WUE during vegetative growth stage, and reductions in nitrogen-use efficiency (NUE) and RWD, were observed with increasing N application. Compared with non-N treatment, N treatment increased yield by up to 98.9 and 93.7% in 2012-2013 and 2013-2014, respectively, decreasing RWD by 12.0 and 16.9%. Correlation analysis further revealed that RWD was positively correlated with grain yield, evapotranspiration (ET) and NUE. NUE was also positively correlated with nitrogen uptake efficiency (UPE). Overall, the findings suggest that optimal N application improves NUE by increasing above-ground nitrogen uptake as a result of optimized RWD and a synchronous increase in WUE, thus increasing yield. Under the experimental conditions, an N application rate of 240 kg N ha plus irrigation at jointing and flowering is recommended.

A mechanistic understanding of the carbon (C) cycle-climate change feedback is essential for projecting future states of climate and ecosystems. Here we report a novel field mechanism and evidence supporting the hypothesis that nocturnal warming in a temperate steppe ecosystem in northern China can result in a minor C sink instead of a C source as models have predicted. Nocturnal warming increased leaf respiration of two dominant grass species by 36.3%, enhanced consumption of carbohydrates in the leaves (72.2% and 60.5% for sugar and starch, respectively), and consequently stimulated plant photosynthesis by 19.8% in the subsequent days. Our experimental findings confirm previous observations of nocturnal warming stimulating plant photosynthesis through increased draw-down of leaf carbohydrates at night. The enhancement of plant photosynthesis overcompensated the increased C loss via plant respiration under nocturnal warming and shifted the steppe ecosystem from a minor C source (1.87 g C·m⁻²·yr⁻¹) to a C sink (21.72 g C·m⁻²·yr⁻¹) across the three growing seasons from 2006 to 2008. Given greater increases in daily minimum than maximum temperature in many regions, plant photosynthetic overcompensation may partially serve as a negative feedback mechanism for terrestrial biosphere to climate warming.

Less than 20% of melanoma patients respond to programmed cell death-1 (PD-1) blockade immunotherapies. Thus, it is crucial to understand the dynamic changes in the tumor microenvironment (TME) after PD-1 blockade, for developing immunotherapy efficacy. A genomic analysis was conducted by The Cancer Genome Atlas (TCGA) datasets and web platform TIMER2.0 datasets. Pathway enrichment analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Peripheral blood mononuclear cells (PBMCs), regulatory T (Treg) cells, and B16-F10 melanoma mice were used as models. The cellular and molecular characteristics and mechanisms of Treg cells in melanoma were assessed by performing gene expression studies, immunohistochemistry, RNA sequencing, and flow cytometry. Here, we evaluate the countenance of T cell immunoglobulin and mucin-domain containing-3 (Tim-3), and various immunosuppressive factors within tumor-infiltrated Treg cells after treatment with anti-PD-1 or the indicator transduction and activator of transcription 3 (STAT3) inhibitors. Increased expression of Tim-3 is markedly observed within the tissues of the PD-1 blockade resistance of melanoma patients. Targeting STAT3 significantly boosts the response of resistant-PD-1 therapy within the melanoma mouse model. Mechanistically, the manifestation of STAT3 decreases the expression of Tim-3 and various cytokines in the purified Treg cells from individual PBMCs and the murine melanoma model, limiting the immunosuppression of Treg cells. Our findings indicate that Tim-3 expression on Treg cells within the TME is STAT3-dependent, providing support to STAT3 as a target and enhancing the immunotherapy for patients suffering from melanoma.

Accurate and efficient cloud detection is critical for maintaining the usability of optical remote sensing imagery, particularly in large-scale Earth observation systems. In this study, we propose FEMNet, a lightweight dual-branch network that combines state space modeling with convolutional encoding for multi-class cloud segmentation. The Mamba-based encoder captures long-range semantic dependencies with linear complexity, while a parallel CNN path preserves spatial detail. To address the semantic inconsistency across feature hierarchies and limited context perception in decoding, we introduce the following two targeted modules: a cross-stage semantic enhancement (CSSE) block that adaptively aligns low- and high-level features, and a multi-scale context aggregation (MSCA) block that integrates contextual cues at multiple resolutions. Extensive experiments on five benchmark datasets demonstrate that FEMNet achieves state-of-the-art performance across both binary and multi-class settings, while requiring only 4.4M parameters and 1.3G multiply–accumulate operations. These results highlight FEMNet’s suitability for resource-efficient deployment in real-world remote sensing applications.

The intensive use of synthetic nitrogen fertilizers over the last century has both increased agricultural productivity and modified biogeochemical cycles in terrestrial ecosystems, causing severe negative environmental impacts. Tea ( Camellia sinensis L.) plantations usually receive high levels of synthetic fertilizers, which strongly affect plant and soil properties. However, there is no quantitative study to assess how synthetic N additions affect soil chemistry and the production and quality of tea shoots. Here, we conducted a comprehensive meta-analysis to evaluate the effects of experimental synthetic N fertilizers. Our main findings are (1) N additions in tea plantations acidify soils (− 0.41 pH unit in average) and produce soil nutrient imbalance. Soil acidification commonly exacerbates the accumulations of toxic aluminum ions. (2) Synthetic N fertilizer additions may strongly increase tea production by almost 70% but alter tea shoot quality by increasing the concentrations of free amino acids (+ 16%), caffeine (+ 14%), and water extracts (+ 5%) while decreasing those of soluble sugars (− 8%) in the tea shoots. The responses of soil chemistry, tea production, and quality to N additions can vary among experimental conditions, tea tree species, and N fertilizer forms. Because there is statistical limitation in this meta-analysis, our findings recommend performing additional field studies to explore the potential mechanisms of nutrient cycling and ecosystem functioning under synthetic N additions. The development of a sustainable N management strategy in tea plantations is also urgently needed to enhance N use efficiency and reduce environmental risks.

Excessive or improper nitrogen (N) application rates negatively affect crop production and thereby environmental quality, particularly for winter wheat production in the North China Plain. Therefore, it is very important to optimize N fertilizer input to balance grain yield, environmental risk, and benefits under irrigated conditions. Three long-term stationary field experiments including five N levels, from 0 to 300 kg ha [0 (N0), 90 (N90), 180 (N180), 240 (N240), and 300 (N300) kg ha ] were carried out to investigate the effects of N regime on wheat yield, photosynthesis, and N balance at different sites. The grain yield and protein content increased quadratically with N rate, and the maximum values were 8087 kg ha and 13.9% at N application rates of 250 and 337 kg N ha , respectively. N application increased the photosynthetic fluorescence parameters (Pn, Gs, and Tr) and N metabolism enzyme activities (NR and GS) which then increased grain yield. The leaching of soil nitrate into the deeper soil layers ( > 100 cm) increased with higher N fertilization and experimental years. The partial factor productivity (PFPN) was decreased by N because the apparent N loss increased with N application rate. In order to balance grain yield, N use efficiency (NUE), and N loss, the recommended N rate should be 120-171 kg N ha , and the corresponding yields and apparent N loss were 7278-7787 ka ha and 22-37 kg ha , respectively.

Background Numerous individual studies have investigated the diagnostic value of EBV-DNA, EA-IgA, VCA-IgA, EBNA1-IgA and Rta-IgG detection for nasopharyngeal carcinoma (NPC), but the conclusions remain controversial. This meta-analysis aimed to determine the value of EBV-DNA, EA-IgA, VCA-IgA, EBNA1-IgA and Rta-IgG detection in the diagnosis of NPC. Methods PROSPERO registration number: CRD42019145532. PubMed, EMBASE, Cochrane Library, and Chinese data libraries (Wanfang, CNKI, and CBM) were searched up to January 2019. The pooled sensitivity, specificity, and positive likelihood, negative likelihood, and diagnostic odds ratios were conducted in this meta-analysis. Summary receiver operating characteristic curves evaluated the test-performance global summary. Publication bias was examined by Deek’s funnel plot asymmetry test. Results Forty-seven studies with 8382 NPC patients (NPC group) and 15,089 individuals without NPC (Control group) were included in this meta-analysis. The sensitivity, specificity, positive likelihood (+ LR), negative likelihood (-LR), DOR and AUC of EBV-DNA in diagnosis of NPC were: 0.76 (95% CI 0.73–0.77), 0.96 (95% CI 0.95–0.97), 14.66 (95% CI 9.97–21.55), 0.19 (95% CI 0.13–0.28), 84 (95% CI 50.45–139.88), 0.96 ( SE : 0.001), and 0.55 (95% CI 0.54–0.57), 0.96 (95% CI 0.96–0.97), 12.91 (95% CI 9.55–17.45), 0.35 (95% CI 0.29–0.43), 39.57 (95% CI 26.44–59.23), 0.94 ( SE: 0.002) for the EA-IgA , and 0.85 (95% CI 0.84–0.85), 0.89 (95% CI 0.88–0.89), 6.73 (95% CI 5.38–8.43), 0.17 (95% CI 0.12–0.23), 43.03 (95% CI 31.51–58.76), 0.93 ( SE : 0.007) for the VCA-IgA , and 0.86 (95% CI 0.85–0.88), 0.87 (95% CI 0.88–0.90), 7.55 (95% CI 5.79–9.87), 0.16 (95% CI 0.13–0.19), 50.95 (95% CI 34.35–75.57), 0.94 ( SE: 0.008) for the EBNA1-IgA , and 0.70 (95% CI 0.69–0.71), 0.94 (95% CI 0.94–0.95), 9.84 (95% CI 8.40–11.54), 0.25 (95% CI 0.21–0.31), 40.59 (95% CI 32.09–51.35), 0.95 ( SE: 0.005) for the Rta-IgG . The EBV-DNA had larger AUC compared with other EBV-based antibodies ( P  < 0.05), while the difference between EA-IgA, VCA-IgA, EBNA1-IgA and Rta-IgG was not statistically significant ( P  > 0.05). Conclusions EBV-DNA, VCA-IgA, EBNA1-IgA and Rta-IgG detection have high accuracy in early diagnosis NPC. In addition, EBV-DNA detection has the higher diagnosis accuracy in NPC. On the other hand, EA-IgA is suitable for the diagnosis but not NPC screening.