Search Results (6,206)

Environmentally released carbon nanomaterials can alter polycyclic aromatic hydrocarbon (PAH) attenuation in agricultural soils, yet how their properties influence biodegradation in association with contaminant bioavailability and indigenous microbial responses remains unclear. This study compared nano-biochar (NBC), pristine and hydroxylated multi-walled carbon nanotubes (MWCNTs; 4–6 nm and >50 nm) in phenanthrene-contaminated soil, using raw biochar (RBC) as parent reference material. NBC showed the strongest promotion, reaching 68.17% biodegradation at 60 d and a maximum rate of 3.00 mg/kg/d, compared with 58.31% and 2.00 mg/kg/d in the unamended phenanthrene-spiked control. RBC exerted a weaker positive effect, suggesting biochar nanosizing favored biodegradation, accompanied by moderate bioavailability reduction and stimulation of microbial abundance, enzyme activity and diversity. In contrast, MWCNTs inhibited biodegradation, with reduced β-HPCD-extractable phenanthrene, suppressed polyphenol oxidase activity and more pronounced community shifts, while higher abundance of PAH-degradation gene nidA did not correspond to enhanced biodegradation. Pristine MWCNTs showed the lowest initial β-HPCD-extractable phenanthrene and biodegradation rates, whereas small-diameter MWCNTs most strongly limited final biodegradation extent, consistent with greater surface reactivity and intensified cell-contact stress. Hydroxylated MWCNTs exhibited weaker inhibition than pristine counterparts. These findings highlight the importance of material properties in shaping PAH fate and microbial ecology in agricultural soils. Full article

Atmospheric oxidation capacity is a key parameter for measuring the atmosphere’s self-cleaning ability. Its strength directly affects the degradation rate of pollutants such as methane, carbon monoxide, and nitrogen oxides, and has a profound impact on regional air quality, ecosystem health, and even global climate chemistry processes. Against the backdrop of increasing global anthropogenic emissions and rapid climate system changes, quantitatively assessing the spatiotemporal evolution of atmospheric oxidation capacity is particularly important. This study systematically simulated and assessed the atmospheric oxidation capacity of Guangdong Province in October 2017 based on the Weather Research and Forecasting with Chemistry model (WRF-Chem). To more scientifically quantify atmospheric oxidation capacity, this study examined a new observational index, AOC_TOX (the rate atmospheric oxidants being reduced), and compared it to the traditionally used index AOC_ODT (the rate atmospheric reductants being oxi32dized). The results show that the AOC_TOX and AOC_ODT indices exhibit a high degree of consistency in both temporal variation trends and spatial distribution patterns. Temporally, the diurnal variation characteristics of the AOC_TOX and AOC_ODT indices are highly consistent, with 24 h averages of 1.8 × 10⁷ cm⁻³ s⁻¹ and 2.0 × 10⁷ cm⁻³ s⁻¹, respectively, showing minimal difference. Spatially, the high-value and low-value regions of both indices significantly overlap. This result demonstrates the internal consistency of the new AOC_TOX index in characterizing atmospheric oxidation capacity. Furthermore, by analyzing the contributions of different oxidants, this study clarifies that hydroxyl radicals (OH) are the main driving force of atmospheric oxidation capacity during the day, while nitrate radicals (NO₃) play a dominant role at night. Finally, simulation analysis further reveals that human activity emissions are a key factor regulating the spatial pattern of regional atmospheric oxidation capacity. Full article

Background/Objectives: The whole plant of Tetrastigma hemsleyanum is used medicinally, but the tuberous root is by far the most commonly used part, and the way in which its metabolites are partitioned among organs and among geographic origins underpins both the rational choice of the medicinal part and the evaluation of herb quality. Methods: Here, untargeted metabolomics based on ultra-high-performance liquid chromatography coupled to high-resolution Orbitrap mass spectrometry was used to compare roots, stems and leaves collected from nine regions of southern China (81 samples) with tuberous roots collected from 17 sites in seven provinces (51 samples). Annotations were graded according to the Metabolomics Standards Initiative (MSI), curated with explicit plausibility rules, and every conclusion was re-tested across five nested annotation subsets. Results: Organ identity was the dominant source of metabolic variation: the three organs were completely separable (random forest out-of-bag accuracy 100%), the organ effect was about four times larger than that of sampling region (PERMANOVA pseudo-F 16.7 versus 4.1), and this contrast was essentially unchanged from the complete set of 615 annotations down to the most stringent subset of 19 flavonoids and phenolic acids. The organ-level pattern was chemically coherent: amino acids and lipids were relatively enriched in the tuberous root, soluble sugars and phenolic acids in the stem, and flavonoids and alkaloids in the leaf, matching the contrasting roles of a storage, a transport and a photosynthetic organ. Geographic differences among tuberous roots were, by contrast, weak and largely local: although provinces could be separated with 88.9% out-of-bag accuracy, accuracy fell to 42.2% when an entire, previously unseen collection site was held out (chance level 20%), and to 52.9% for a coarse macro-geographic zone (chance level 25%), whereas holding out an entire sampling region left organ classification unaffected (100%). Conclusions: The present data therefore document a strong, generalisable and chemically interpretable organ division of labour, but do not support the use of this metabolome for origin authentication. Because most annotations remain at MSI Level 3, individual compounds are reported as putative throughout, and all conclusions rest on multivariate and class-level evidence. Full article

Background: Antimicrobial resistance is a major global health challenge, with multidrug-resistant organisms (MDROs) emerging faster than new antimicrobial agents are being developed. The epidemiology of MDROs varies substantially across healthcare settings; however, newly established hospitals remain understudied. This study aimed to characterise the epidemiology and temporal trends of MDROs in a newly established tertiary hospital. Methods: A five-year retrospective longitudinal surveillance study was conducted from 2019 to 2023 in a newly established tertiary hospital in Southern China. Clinical isolates were collected from intensive care unit (ICU) and non-ICU wards. Nine major MDROs were investigated, including extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) and Escherichia coli (ESBL-ECO); carbapenem-resistant Klebsiella pneumoniae (CRKP), Escherichia coli (CRECO), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA); methicillin-resistant Staphylococcus aureus (MRSA); and vancomycin-resistant Enterococcus faecium (VREfm) and Enterococcus faecalis (VREfa). Results: A total of 1533 MDRO isolates were identified during the study period. The predominant pathogens were ESBL-ECO (48.1%), ESBL-KP (16.4%), MRSA (11.4%), and CRPA (11.1%). Most isolates were recovered from non-ICU wards (85.4%), and more than half (51.5%) were community-onset. Isolation rates of ESBL-ECO, CRECO, CRAB, and CRPA were significantly higher in the ICU than in non-ICU wards (all p < 0.05). The incidence density rate of hospital-acquired infections caused by ESBL-KP, CRAB, and CRPA was also significantly higher in the ICU (all p < 0.05). Longitudinal analysis revealed divergent trends among MDROs. While most MDRO isolation rates remained below provincial and national benchmark levels, CRKP and CRAB showed significant increasing trends. CRPA exhibited a distinct pattern, increasing rapidly during the early years after hospital opening, exceeding both provincial and national benchmarks by the second year and remaining elevated thereafter. Conclusions: MDRO epidemiology during the first five complete calendar years after hospital opening was characterised by a predominance of ESBL-ECO, ESBL-KP, MRSA, and CRPA, together with substantial non-ICU and community-onset burdens and heterogeneous temporal patterns across organisms. CRPA increased rapidly and remained above the available external benchmark thereafter. These findings highlight the need for hospital-wide, organism-specific MDRO surveillance, while maintaining intensified infection prevention and control in ICUs and continued vigilance for carbapenem-resistant pathogens, particularly CRPA. Full article

Amid rising population pressure, heightened volatility in international markets, and increasingly binding domestic resource and environmental constraints, safeguarding food security while maintaining ecological security has become a salient policy and academic concern in China. Within this context, our study investigates whether and how green finance contributes to the dual security of food and ecology. Building on a theoretical analytical framework, we elaborate on the functional role of green finance and empirically assess its effects using provincial panel data from China. We construct a composite index to gauge the level of green finance development and then employ a two-way fixed-effects model with province and year fixed effects to identify the overall impact of green finance, followed by a mediation model to uncover the underlying transmission mechanisms and sub-sample regressions to examine heterogeneity. The empirical evidence indicates that, while green finance significantly improves the dual security of food and ecology, substantial heterogeneity is observed, with stronger effects in southern regions, major grain-producing functional areas, and plain regions. Mechanism analyses further show that green finance advances dual security through three primary channels of agricultural structure adjustment, planting specialization, and agricultural green technological innovation, among which shifts in agricultural production structure, greater centralization of planting, and enhanced agricultural green innovation capacity constitute the dominant transmission mechanisms. By integrating food security and ecological security within a unified framework, we clarify the multidimensional pathways through which green finance supports sustainable agricultural development and provide new empirical evidence on how financial instruments can reconcile production and environmental objectives. Full article

Clarifying ecosystem service interactions under urbanization facilitates integrated ecological governance. This study took the rapidly urbanizing Su-Xi-Chang agglomeration in the Yangtze River Delta as the research area and applied the InVEST model to evaluate spatiotemporal variations in carbon storage, soil retention, water yield, and habitat quality from 2000 to 2023. The coupling coordination degree model and self-organizing map model were adopted to analyze urbanization–ecosystem interactions and the evolution of ecosystem service bundles, while the GeoDetector model was used to identify key socio-ecological drivers. The results reveal significant spatiotemporal divergences among the four ecosystem services. Carbon storage and habitat quality declined, while water yield and soil retention increased. Carbon storage and soil retention hotspots were persistently concentrated in the Yixing–Liyang Mountainous Area. Pairwise correlations further show that the synergy between water yield and soil retention strengthened over time, whereas their trade-offs with habitat quality intensified. The coupling coordination between urbanization and ecosystem services remained at a primary level yet exhibited a clear trajectory from imbalance toward optimization after 2010. Four ecosystem service bundles were identified, among which the urban-function-dominated bundle expanded by 190.39% from 2000 to 2023, indicating progressive spatial lock-in of urban land use. Differentiated zoning and targeted restoration strategies are proposed to reconcile urban development and ecological conservation. This study offers scientific references for ecological spatial optimization and refined ecological management in the Yangtze River Delta. Full article

Prediction of 2 m temperature during extreme cold events remains challenging because it is obtained diagnostically from near-surface atmospheric states and depends on various physical parameterization processes, thereby introducing multiple sources of forecast uncertainty. Our previous study has demonstrated that the Combined Nonlinear Forcing Singular Vectors (C-NFSVs) based ensemble forecasts can effectively characterize forecast uncertainty and recognize the dominant sources. However, the specific dynamical and physical parameterization processes associated with model-related forecast uncertainty remain unclear. In this study, we investigate the sensitivity of model-related 2 m temperature forecast uncertainty within the Weather Research and Forecasting (WRF) model to different dynamical and physical parameterization processes during extreme cold events over southern China. Based on the good reliability of C-NFSVs-based ensemble forecasts, the sensitivities of different temperature tendency terms to model perturbations were diagnosed by comparing the ensemble spreads from experiments using full C-NFSVs and those using only the initial component of C-NFSVs. The results indicate that, for the extreme cold events examined over southern China, the vertical advection and Planetary boundary layer (PBL) parameterization terms in the WRF model exhibit the strongest sensitivities to model perturbations, suggesting their close association with model-related 2 m temperature forecast uncertainty. This sensitivity may be associated with the roles of these processes in regulating the vertical redistribution of heat and the evolution of lower-tropospheric thermal structures. These findings provide new insights into the processes associated with model-related forecast uncertainty of 2 m temperature. Furthermore, they highlight the need for further investigations of vertical advection and PBL-related processes in the WRF model. Such investigations are expected to improve the understanding of their roles in forecast uncertainty and evaluate their potential implications for improving 2 m temperature forecasts during extreme cold events. Full article

The equitable allocation of health resources is fundamental to building healthy cities and advancing sustainable regional development. Using panel data for 122 county-level units in Hunan Province, China, from 2011 to 2022, this study constructs an evaluation index system for healthcare resource allocation and applies trend surface analysis, spatial autocorrelation, the Dagum Gini coefficient, and geographically and temporally weighted regression (GTWR) to examine the spatiotemporal evolution, equity, and driving factors of health resource allocation. The results show the following. (1) The level of health resource allocation in Hunan Province rose steadily, with the composite score increasing by 74%, yet a persistent spatial pattern of higher allocation in the east and north than in the west and south remained; hot spots clustered in Changsha, while cold spots concentrated in parts of Southern Hunan and Western Hunan. (2) Regional disparities narrowed gradually, and the Dagum decomposition identified transvariation density as the dominant source of inequality, with an average contribution of 53.58%, exceeding intra-group and inter-group differences. (3) The effects of the drivers exhibited marked spatiotemporal heterogeneity. Per capita GDP promoted health resource allocation mainly in developed regions, while urbanization exerted stronger positive effects in less-developed regions. The positive effect of per capita disposable income gradually shifted from less-developed to developed regions over time, and population density generally showed a positive effect, with stronger influences concentrated in the Greater Western Hunan region. This study contributes to a deeper understanding of how regional disparities and heterogeneous driving mechanisms shape health resource allocation, providing evidence for more adaptive and equitable healthcare governance. Full article

Background: Cunninghamia lanceolata (Lamb.) Hook. (C. lanceolata) is an important timber tree species in southern China. However, the molecular regulatory mechanisms underlying adventitious root formation during cutting propagation remain largely unclear. The lack of genetic resources has hindered molecular breeding efforts in this species. Methods: In this study, transcriptome analysis was performed on the root systems of scions from elite C. lanceolata clones at 7, 30, and 60 d after cutting. Results: Approximately 69.30 Gb of clean data were obtained. De novo assembly and gene prediction yielded 43,433 protein-coding genes, of which 32,886 (75.7%) were functionally annotated. Temporal clustering and comparative functional enrichment analyses revealed a distinct temporal functional shift during adventitious root development in C. lanceolata. Early stages were dominated by metabolic processes such as pyrimidine metabolism and carbohydrate biosynthesis, whereas later stages were governed by phytohormone signal transduction. Key components of the auxin pathway, including AUX1, AFB, IAA, and SAUR, exhibited dynamic and differential expression, which may be associated with adventitious root growth. Based on the transcriptome data, we identified nine members of the PIN gene family. Both transcriptomic expression profiles and qRT-PCR validation demonstrated that these PIN genes showed divergent expression trends across developmental stages, suggesting that they may participate in rooting by regulating polar auxin transport. Conclusions: This study systematically elucidates the molecular network underlying adventitious root formation in C. lanceolata cuttings. It enriches the omics resources for conifers and provides a theoretical foundation and omics basis for molecular breeding and efficient propagation of elite C. lanceolata clones. Full article

Common reed (Phragmites australis) is a native dominant plant in many coastal wetlands. To determine how rhizosphere effects and soil depth shape microbial communities, we sampled the rhizosphere and three bulk-soil layers (0–15, 15–30, and 30–45 cm) in a monodominant common-reed stand in a coastal salt marsh. Soil physicochemical properties and bacterial and fungal α-diversity, community composition, and assembly processes were evaluated using one-way ANOVA, principal coordinates analysis (PCoA), permutational multivariate analysis of variance (PERMANOVA), neutral community models, and phylogenetic null models. Rhizosphere pH was lower than that of 0–15 cm bulk soil (mean 8.434 vs. 8.712) but remained alkaline; soil organic matter, total nitrogen, hydrolyzable nitrogen, and total phosphorus were greatest in the rhizosphere. Neither bacterial nor fungal richness or Shannon diversity differed significantly among compartments (p > 0.05); fungal Shannon means ranged from 2.083 to 3.077, with relatively higher Bacteroidota and lower Acidobacteriota abundance in the rhizosphere. Fungal composition did not differ significantly (pseudo-F = 0.609, R² = 0.102, p = 0.9112), although Mucoromycota and Rozellomycota were relatively more abundant in the rhizosphere. Phylogenetic null models indicated predominantly deterministic bacterial assembly, with 10% dispersal limitation in the 15–30 cm layer. Fungal assembly was predominantly stochastic in bulk soils, whereas the rhizosphere was an exception: heterogeneous selection accounted for 60% of pairwise comparisons and median βNTI exceeded +2. The Mantel test identified only the association between total phosphorus and bacterial diversity as significant (0.01 < p < 0.05). These results show that rhizosphere filtering strongly structured bacterial composition and imposed deterministic selection on rhizosphere fungi. Full article

During CO₂ flooding, unfavorable mobility ratios and interlayer heterogeneity can induce preferential flow through high-permeability intervals, leaving central low-permeability intervals insufficiently swept and rich in remaining oil. To address the strong coupling among composite chemical-plugging parameters and the high computational cost of CMG-STARS simulations for individual candidate strategies, this study proposes an adaptive heterogeneous ensemble surrogate-assisted differential-evolution method (AHES-DE). The method integrates radial basis function, inverse-distance weighting, and ridge-linear surrogate models, whose predictions are dynamically weighted according to leave-one-out cross-validation errors. Explorer, Exploiter, and Robust roles are used for global search, local exploitation, and prediction-risk control, respectively, with differential-evolution offspring generation embedded in the Exploiter role. A stratified one-injector–four-producer conceptual model with a 21 × 21 × 6 grid was used to establish a numerical evaluation workflow comprising CO₂ injection, preferential-channel development, composite chemical plugging, and subsequent displacement. Mobile chemical concentration, adsorbed preformed particle gel (PPG) mass density, water-phase resistance factor, oil saturation at a common termination time, and net economic value (NEV) were used to evaluate treatment performance. Under an equal budget of 150 high-fidelity CMG-STARS evaluations per method, the reported single-seed final best-so-far NEVs were 2.45405 × 10⁹ CNY for AHES-DE, 2.44888 × 10⁹ CNY for differential evolution (DE), and 2.44698 × 10⁹ CNY for Latin hypercube sampling (LHS). The layer-resolved responses indicate more pronounced chemical transport, retention, and resistance development in the upper and lower preferential intervals, while the oil saturation in the central low-permeability interval decreased further after treatment, indicating that flow redistribution facilitated remaining-oil mobilization. A realistic geological model was further used to assess the engineering consistency of the identified flow-control mechanism. Full article

The Dajing Cu-Sn polymetallic deposit, situated within the southern Great Xing’an Range of northern China, is a representative Mesozoic magmatic–hydrothermal system within a major Cu–Sn–Ag–Pb–Zn metallogenic belt. Located at the junction between the Siberian and North China plates, the deposit occurs within a composite tectonic domain overprinted by the Paleo-Asian, Mongol–Okhotsk, and Paleo-Pacific systems. Building on field geological constraints and detailed ore petrography, this study utilizes SEM–CL imaging and in situ LA–ICP–MS trace-element analysis of hydrothermal quartz to reconstruct the multistage physicochemical evolution and fluid dynamics of the ore-forming system. Three quartz generations record successive mineralization stages: early QI forms grain cores associated with Stage I cassiterite–arsenopyrite–quartz mineralization; main-stage QII crystallized during or shortly after Stage II chalcopyrite precipitation and exhibits well-developed oscillatory zoning; and late QIII occurs mainly as rim overgrowths and fracture fillings and postdates Stage III ore-mineral precipitation. Quartz is characteristically Ti-poor (4.7–22.8 ppm), and its trace-element systematics indicate a low- to intermediate-temperature hydrothermal signature and a granitic magmatic–hydrothermal affinity. Al, Li, Na, K, and Ge show coupled behavior consistent with heterovalent substitution and vary markedly among quartz generations, with CL-bright QIIa showing relatively higher Al, Ge, and Na relative to CL-dark QIIb, whereas QIII is generally characterized by lower Al, Li, and Ge. Localized anomalously high Cu and Sn values are mainly attributed to the co-ablation of fine-grained mineral inclusions, metal-rich fluid inclusions, or fracture-filling components. These features indicate a chemically heterogeneous fluid reservoir with inferred relatively acidic conditions during the initial Sn-mineralization stage. The fluid system subsequently experienced recurrent physicochemical fluctuations associated with pulsed fluid input during the principal Cu-mineralization stage. QIII records a trace element-depleted late-fluid system associated with the terminal pyrite–quartz stage. Late fluids migrated along earlier quartz boundaries and fractures and may have undergone further cooling and dilution through fluid mixing and/or water–rock interaction. Overall, the fluid system shows a progressive shift in inferred fluid chemistry, consistent with decreasing acidity during hydrothermal evolution. Full article

Yellow-flowered camellias are a sought-after rarity that has a narrow natural distribution in southern China and northern Vietnam. Belonging to the Camellia sect. Chrysantha Chang, many of the yellow-flowered camellia species are endangered. In this study, whole-genome resequencing (WGR) was applied to a collection of 25 yellow-flowered camellias in the United States of America to generate molecular markers and estimate genetic diversity. A total of 200,385,257 SNPs, 15,632,190 indels, 420,648 structural variations, and 9067 CNVs were identified among the 25 plants. There were 122 SNPs within the chalcone synthase (CHS) gene. Two groups of plants, C. nitidissima and hybrids, were distinctly separated from the other individuals. High within-population diversity and moderate among-population differentiation were found. Compared to the genetic diversity present in the native regions of yellow-flowered camellias, only a limited number of species have been introduced to the United States. The current study is the first report of whole-genome resequencing of yellow camellias and the first investigation of genetic diversity and structure of a collection of individuals from the U.S. This significant genomic resource shall have a meaningful impact on conservation and breeding, as well as on species identification and evolution studies. The genetic diversity information shall guide the efforts in breeding and the introduction of new species. Full article

Proximate analysis is essential for assessing the nutritional composition of legumes. Near-Infrared Spectroscopy (NIRS) is widely used as a rapid, non-destructive method. However, commercial NIRS calibration models are primarily developed using major commercial legumes and may not represent the spectral variability of underutilised legumes, limiting their transferability across species. This study aimed to evaluate the proximate composition of local market legumes and adjust existing NIR equations for predicting proximate constituents. Twenty-six dry seed legume samples, representing four genera and multiple species from northern Thailand and southern China, were analysed using standard wet-chemistry methods. Reference analyses showed that soybeans contained the highest protein and fat levels among the legumes studied. Partial Least Squares regression was used to adjust prediction models, with 5–7 newly acquired samples per model. Model performance was evaluated using leave-two-out cross-validation. The adjusted models yielded root mean square error values of 0.987, 0.586, 0.671, 0.363, and 0.976 for protein, fat, moisture, ash, and fibre, respectively. Spectral adjustment improved agreement between predicted and reference values, particularly for protein, fat, and ash. This study demonstrated the initial potential of adapting existing NIRS calibration models to diverse legumes. Future work must prioritise independent external validation with expanded sample cohorts to establish operational robustness. Full article

Winter green manure incorporation is widely practised in southern China, yet its effect on soil carbon and nitrogen cycling gene abundances across a full ratoon rice cycle remains unclear. A field experiment combined three cropping systems differing in winter management (winter fallow–ratoon rice, FA; rapeseed–ratoon rice, RA; and Chinese milk vetch–ratoon rice, MV) with two ratoon rice varieties (Yliangyou 911 and Liangyou 6326). Soil properties and functional gene abundances were measured at three soil depths and three sampling stages, and theoretical grain yield was determined in the main and ratoon seasons. Green manure incorporation did not change the bulk physicochemical properties of the soil as a general effect but altered its labile carbon and nitrogen pools. Dissolved organic carbon under RA and MV was, respectively, 24.28% and 16.15% higher than under FA, and ammonium nitrogen under MV in the ratoon season was up to 193.04% higher than under FA, exceeding RA throughout the profile. The functional genes responded in contrasting directions. pmoA, mcrA, nirK and nosZ were lower under green manure (pmoA 20.00% and 14.53% lower under RA and MV), whereas AOA amoA, cnorB and nirS were higher (AOA amoA 0.42 and 0.55 log units higher), with the clearest shifts occurring in the ratoon season and the surface soil. Correlation, redundancy and path analyses indicated that the gene–environment associations were linked mainly to ammonium nitrogen, dissolved organic carbon and nitrate nitrogen, and that winter treatment was associated with yield indirectly, most closely through the soil carbon pool (standardized total effect 0.34–0.57), rather than acting on yield directly. Full article