Heavy metal contamination in urban soils poses a significant threat to sustainable development and public health. Therefore, a systematic evaluation of the sources and risks of heavy metals in urban soils is essential. This study applies an improved Nemerow index, the matter-element extension model, and a Monte Carlo-based health risk model. In addition, it integrates lead isotope analysis, correlation analysis, Self-Organising Maps (SOM), Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR), and the MixSIAR isotopic mixing model. These methods are combined to enable accurate source apportionment and source-specific risk assessment. The results indicate that the high-value zones of all eight heavy metals are mainly distributed in the southeastern part of the city. The overall ecological risk remains at a controllable level. Carcinogenic and non-carcinogenic risks for adults are negligible, whereas those for children reach 27.30 % and 3.14 %, respectively. Lead-isotope signatures indicate that coal combustion and traffic emissions are the principal sources of lead in soil. Source-health risk analysis suggests that coal combustion is likely an important contributor to overall pollution, with arsenic (As, a metalloid) and its coal-related inputs likely warranting greater attention in control strategies. Children appear to be a more vulnerable group requiring targeted protection. This study provides policy recommendations for preventing and controlling soil pollution in Lanzhou. It also bridges the gap in precise source identification and source-based risk assessment for urban soils.

COPs (combustion organic carbons) are a type of pollutant generated during fuel combustion, and the rapid accumulation of COPs in lake environments poses a serious threat to watershed climate change and lake ecological security. Taihu was used as the study area, and the concentrations of char in the surface sediments of Taihu were significantly higher than those of soot, with average concentrations of 2.2 and 0.5 mg kg− 1 respectively. In combination with 137CS and 210Pb dating technologies, the historical concentrations of COPs in Taihu have been reconstructed for the past century. The concentrations of all COPs have increased rapidly since the reform and opening up and have remained stable since approximately 2003, which is closely related to China’s industrial economic development and legal measures for environmental protection. Combined with the source apportionment receptor model, the contribution amount of each pollution source to the COPs in the sediment of Taihu in the past century was quantified. In the past hundred years, biomass sources have made relatively stable contributions to COPs in the Taihu Lake sediments. With the rapid development of social economy, the amount of petroleum fossil fuel combustion has increased year by year, and the COPs contributions to the Taihu Lake sediments have also increased rapidly in the past 40 years, becoming the main source of COP.

Methylmercury (MeHg) in coastal sediments poses significant ecological and human-health risks due to its high toxicity, strong bioaccumulation potential, and mobility within benthic environments. This study investigates the spatiotemporal distribution, preservation mechanisms, and historical burial fluxes of MeHg in surface sediments and sediment cores collected from Jiaozhou Bay (JZB), a semi-enclosed and urbanized bay in northern China. Surface sediments exhibited low-to-moderate MeHg concentrations (0.03-0.37 ng/g) with a pronounced east-west concentration gradient. Higher MeHg levels were found in the northeastern estuary and the bay mouth, primarily driven by elevated inorganic Hg inputs (from riverine and wastewater sources) and enhanced methylation potential. Correlation analyses revealed that MeHg concentrations in surface sediments were weakly and positively correlated with total Hg (p < 0.05). Furthermore, the %MeHg were significantly modulated by key environmental parameters, including total organic carbon, nitrogen, sulfur, and grain size (p < 0.05). In the sediment cores, Core 14 exhibited significant inter-annual variability with a gradual long-term increase; meanwhile, Core 20 showed a sharp increase in 2014-2015, and Core 28 recorded elevated values during the 1990s, 2016, and 2018. The sedimentary MeHg burial fluxes across the cores increased steadily over time, reaching a common peak around 2013-2017. This maximum accumulation is likely due to the combination of increased MeHg inputs and favorable methylation conditions. The maximal MeHg accumulation observed in the subsurface layers of this coastal bay raises significant concern regarding the ecological contamination risk posed by sediments acting as a persistent secondary source.

To investigate the nationwide pollution status of PAHs in sediments and provide data support and clear direction for water pollution control across China, this study systematically integrated publicly available concentration data of PAHs in surface sediments from Chinese water bodies between 1993 and 2023. It reveals their spatiotemporal distribution patterns, source characteristics, and ecological risks. Results indicate that PAHs pollution exhibits a temporal trend of "initial increase followed by decline," peaking around 2006. Spatially, it shows a pattern of "higher concentrations in the east (598.06 ng/g) than in the west (580.97 ng/g), and higher in the north (724.39 ng/g) than in the south (485.98 ng/g)." Source apportionment using two receptor models yielded largely consistent results. Comparison indicated APCS-MLR provided more reliable outcomes, attributing contribution rates as follows: biomass combustion (48.26 %), coal combustion (25.49 %), transportation emissions (13.77 %), and petroleum emissions (12.48 %). Ecological risk assessment using both the risk quotient (RQ) method and the toxicity equivalent (TE) method yielded highly consistent results, indicating the highest ecological risk for PAHs in the Northeast region and the lowest in the Central region. The calculated national overall RQ(NCs) for sediment PAHs was 263.128, and RQ(MPCs) was 2.631, indicating a medium-to-high risk level.

The Jiaozhou Bay (JZB) intertidal zone is a significant carbon reservoir that plays a crucial role in transporting and accumulating organic matter; however, quantitative studies of organic matter sources are scarce. In this study, we present bulk parameters of total organic carbon (TOC), TOC/TN, δ13C, and biomarker contents in 36 surface sediment samples from the JZB intertidal zones to quantify the contribution of organic carbon (OC) derived from terrestrial/marine sources, such as C3 plants, C4 plants, estuarine productivity, sewage outlets, and marine productivity. The results demonstrated that a two-end-member model based on the traditional indicators of TOC/TN or δ13C is not appropriate for quantifying the OC source. The presence of C3 plants, C4 plants, and sewage outlets in the JZB intertidal zone could lead to errors in determining OC contribution when solely using TOC/TN or δ13C. A classical mixing diagram (three-end-member model) utilizing TOC/TN and δ13C values revealed that OC contribution was dominated by marine productivity throughout the intertidal zone. In the west, the average OC contribution from marine productivity, estuarine productivity, and C4 plants was 73.8 %, 14.2 %, and 12.0 %, respectively. In the east, the average OC contribution from marine productivity, estuarine productivity, and sewage outlets was 57.6 %, 24.9 %, and 17.4 %, respectively. The higher OC contribution from marine productivity in the west was attributed to the occurrence of Spartina alterniflora, while the OC contribution from estuarine productivity in the east was primarily due to the presence of more rivers flowing into the JZB compared to the west. By combining biomarkers and OC contents, a significant positive relationship verified the suitability of the end-member values selected for the three-end-member mixing model in the west and east intertidal zones of JZB. This finding was further supported by principal component analysis (PCA) analyses of these proxies. This study demonstrated that OC sources in intertidal zones varied among contrasting coastal environmental conditions and addressed the knowledge gap regarding biogeochemical cycles and ecological protection in the JZB intertidal zones.

The rapid accumulation of black carbon (BC) in the environment has posed a serious threat to climate change and ecological security in river basins. Lakes are important accumulation sinks for BC, and microorganisms in lake sediments play a significant and irreplaceable role in maintaining lake ecological security. However, there has been little research on the impact of BC on lake microorganisms, and studies have focused only on bacteria, neglecting the impact on fungi. Moreover, there is a lack of methods to identify areas where BC poses a risk of microbial contamination. This study used Taihu Lake as the study area and explored the spatial distribution characteristics of BC components, bacteria, fungi and other indicators in the sediment. The accumulation of organic carbon in the Taihu Lake sediments, like BC, has been strongly affected by human activities in recent years. The BC, BCchar and organic carbon contents in Taihu Lake sediments were the main factors affecting the diversity and function of bacteria and fungi. There are differences in the response of bacteria and fungi to BC in the sediment of Taihu Lake, among which the BC mainly played a negative role in bacterial diversity and a positive role in fungal diversity. A risk assessment model for BC on microorganisms has been established, and risk areas for bacteria and fungi have been identified, accounting for 52.0 % and 4.3 % of the total area, respectively. Finally, the spatial clustering characteristics of sediment BC and bacterial and fungal diversity were combined, a comprehensive risk assessment model of the effects of BC on microorganisms was constructed, and the risk areas were accurately identified. The risk areas reached 51.0 % of the total area of Taihu Lake, and the ecological security areas reached 31.1 %. This study provides scientific and systematic methods and technologies for ensuring the security of river and lake ecosystems and preventing and controlling BC pollution.

Lanthanide (Ln) elements form a cofactor complex with pyrroloquinoline quinone (PQQ) in bacterial alcohol dehydrogenases (Ln3 +-ADH). The lanthanide elements did not support Ln3+-ADH activity equally, with only early lanthanides (La3+-Gd3+) promoting high enzyme activity. However, the early lanthanides did not promote the activity equally and the detailed mechanism of Ln3+-ADH exhibiting different activity in the presence of different light Lns remains obscure. To uncover the role of lanthanides in promoting Ln3+-ADH activity, we systemically characterized the activity of an Ln3+-ADH from Pseudomonas putida KT2440 (PedH) in the presence of various Ln3+ ions. In the results, enzyme activity displayed a bell-shaped trend along with the lanthanide series, with Nd3+ providing the highest activity. Active site mutation analysis revealed that modifying the number of coordinating ligands shifted the metal preference of the enzyme. DFT calculation revealed that the HOMO-LUMO gap, substrate interaction energy and metal ions binding distances were critical for the lanthanides in promoting enzyme activity. This work shed light on the critical role of metal ions in Ln3+-ADH catalysis, providing insights for future exploration and engineering of Ln-dependent proteins.

Accurate identification of heavy metals (HMs) pollution sources is a premise for effective management of HMs pollution, while the existing source apportionment methods are subject to greater human subjectivity. Taking agricultural soil in Yiwu City as a case study, based on receptor models, GeoDetector was introduced to compensate for the defects that receptor models could not consider the spatial geographic information, to reduce the interference of anthropogenic subjective judgments on the identification of HMs pollution sources. In this study, the GeoDetector involves natural explanatory variables (slope, aspect, and elevation) and anthropogenic explanatory variables (land use type, pH, and the nearest distance from the sampling site to rivers, factories, roads, railways and residential areas). With the assistance of GeoDetector, the source apportionment results showed that HMs originated from fertilization (43.38 %), emissions from traffic and urban household (32.64 %), and river irrigation (23.98 %). Whether concentration-oriented or source-oriented, probability of health risk for population is very low. Soil HMs had a mild comprehensive environmental capacity (EC) risk (PI = 0.93), and Cd brought by fertilization reached a moderate EC risk (Pi = 0.41). This study can provide reference for the priority control of soil HMs pollution sources, in order to effectively reduce pollution risks.

The landscape pattern has been under stress by both human and natural factors in recent years， resulting in many ecological risks. In this study， the landscape pattern index method was used to assess the landscape ecological risk （LER） in Jiangxi Province from 2000 to 2020， and the spatial autocorrelation approach was applied to investigate the spatial clustering patterns of LER. Then， we used exploratory regression to select the driver combination with the strongest explanatory power and the smallest multicollinearity problem from nine candidate factors. The Geodetector and GTWR model were used to explore the relationship between landscape ecological risk and its driving factors. The results were as follows： ① During the study period， the mean value of landscape ecological risk in Jiangxi Province increased from 0.071 2 to 0.072 5， which is a generally low level. ② From 2000 to 2020， the low-risk area decreased in size by 6.14%， whereas the medium-high risk area and high-risk area expanded by 1.06% and 1.45%， respectively. ③ There was significant spatial autocorrelation of landscape ecological risk in Jiangxi Province. Although the area of spatial agglomeration decreased， the distribution pattern was relatively stable， with low-low agglomeration area in the west， central region， and south and high-high agglomeration area in the north. ④ The explanatory power of natural factors for landscape ecological risk in Jiangxi Province is high， and the explanatory power of the interaction among all factors is stronger than that of a single factor. ⑤ The driving factor combination of population， GDP， annual precipitation， DEM， and NDVI is the combination with the strongest explanatory power. The maximum variance inflation factor （VIF） value of this driving factor combination is 0.06. Population and GDP have positive driving effects on landscape ecological risk in Jiangxi Province， whereas NDVI， annual precipitation， and DEM have inhibitory effects. From the fitting effect， the AICc value and Radj2 value of the GTWR model are -66 139.80 and 0.55， respectively， which is better than the OLS and GWR model result. The results of this study provide a reference for ecological risk management in Jiangxi Province and other regions.

The Loess Plateau, a vital ecological region in China, suffers from severe soil pollution and erosion. The soil fertility index (SFI) is a key indicator for assessing soil conditions, and understanding its spatial distribution and influencing factors is crucial for effective soil management. Machine learning methods, capable of analyzing complex and high-dimensional data, offer potential for large-scale SFI prediction. This study focuses on Lanzhou, a representative city on the Loess Plateau, using soil samples and the data of five key factors screened from environmental big data to train three machine learning models (random forest [RF], LightGBM, and XGBoost) for SFI prediction. The results show that all models effectively matched reference data trend, with XGBoost achieving the highest performance (R-2 > 0.81). Notably, normalized difference vegetation index (NDVI) and soil organic carbon density (SOCD) emerged as the dominant predictors, collectively contributing over 80% to SFI prediction accuracy. Predicted SFI values in Lanzhou ranged from 0.09 to 0.91, with medium and lower quality soils predominantly located in central and north-central regions, highlighting the need for soil quality improvement. This study provides a theoretical basis and scientific support for large-scale SFI prediction.

Although soil combustible organic pollutants (COPs) pose a serious threat to human well-being, their spatial distribution patterns, responses to environmental constraints, and areas of risk throughout China are still unclear. This knowledge gap hinders the control of soil COPs, causing us to overlook their impact on climate change and the environment. In this study, a total of 420 soil samples, distributed in typical regions of China, were tested for COPs content, including black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs). Interest points (POI) such as parking lots, gas stations, and car services have become the main factors that influence soil COPs enrichment, and can be considered new indicators in other organic pollution studies. By comparing various machine learning simulations and predictions, this study accurately predicted the content of soil COPs in China and pointed out that, as the "third pole of the world", the Qinghai Tibet Plateau will face an unprecedented crisis. We established a method for assessing the comprehensive risk of soil COPs and identified at-risk areas, which accounted for 38.9 % of China's total soil area. Our research findings emphasize the main driving factors for soil COPs and identify areas in China that require prioritized soil COPs control.

The disturbance of ecological stability may take place in tropical regions due to the elevated biomass density resulting from heavy metal and other contaminant pollution. In this study, 62 valid soil samples were collected from Sanya. Source analysis of heavy metals in the area was carried out using absolute principal component-multiple linear regression receptor modelling (APCS-MLR); the comprehensive ecological risk of the study area was assessed based on pollution sources; the Monte-Carlo model was used to accurately predict the health risk of pollution sources in the study area. The results showed that: The average contents of soil heavy metals Cu, Ni and Cd in Sanya were 5.53, 6.56 and 11.66 times higher than the background values of heavy metals. The results of soil geo-accumulation index (Igeo) showed that Cr, Mo, Mn and Zn were unpolluted to moderately polluted, Cu and Ni were moderately polluted, and Cd was moderately polluted to strongly polluted. The main sources of heavy metal pollution were natural sources (57.99%), agricultural sources (38.44%) and traffic sources (3.57%). Natural and agricultural sources were jointly identified as priority control pollution sources and Cd was the priority control pollution element for soil ecological risk. Heavy metal content in Sanya did not pose a non-carcinogenic risk to the population, but there was a carcinogenic risk to children. The element Zn had a high carcinogenic risk to children, and was a priority controlling pollutant element for the risk of human health, with agricultural sources as the priority controlling pollutant source.

The long-term changes of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in sediments can reflect the ecological risks (ER) caused by their pollution sources in different historical periods. This is of great significance to the improvement of environmental protection policies in the future. The study area is located in Taihu Lake, China. 137Cs and 210Pb were used for dating. Indicators related to local socio-economic development were introduced to optimize source identification in the absolute principal component score multiple linear regression (APCS-MLR) model. On this basis, the mean effect range median quotient (M-ERM-Q) method was used to evaluate the ER of source-oriented HMs and PAHs at different ages. The HMs content was relatively stable from 1949 to 2015, and then increased significantly. The PAH contents were on the rise during the whole historical period. The average contribution rate of traffic emission and fertilization to HMs was 50.59 % and 49.41 %. Ecological risk caused by Traffic emitted pollutants was relatively stable before 2015, then increased sharply, and finally reached a medium–high level. However, fertilization ER has always maintained an increasing trend and accelerated after 1980, ultimately reaching medium–low ER. The contribution rates of coal combustion, mixed sources (biomass and coal) and gasoline combustion to PAHs were 13.20 %, 52.45 % and 34.36 %, respectively. The ER of mixed sources and gasoline combustion showed a gradually increasing trend before 2007, and then began to decrease. However, coal combustion ER has been increasing, and the increase accelerated in 2000. Nevertheless, the ER of these three sources was still low. Overall, a certain degree of HMs pollution has been caused by traffic emissions and fertilization in recent years. Local governments should prioritize the control of these two sources to protect the Taihu Lake ecosystem.

Multi-medium heavy metals pollution is a crucial pathway to destroy the urban environmental resources cycle. In this study, Nanjing of China, a typical mega city, was taken as the study area. Compared with other cities or countries, Cr, Cu and Zn in human nails and hair in the study area have higher concentration characteristics, while Cd and Pb have lower concentration characteristics. By combining the health risk status of heavy metals in soil and dustfall, the spatial clustering characteristics of heavy metals in soil dustfall and the concentration information of heavy metals in humans in the study area, a potential toxic risk area identification method based on soil-dustfall-human (SDB-HR) was established. Through Monte Carlo analysis, it’s found that the risk of Zn and Cr in soil-dustfall to human health is relatively high, with the probability of carcinogenesis reaching 51.2 % and 50.2 %, respectively. By the proposed method, different levels of heavy metal risk areas in urban environments can be more reasonably and effectively identified, which will provide important technical and theoretical support for the precise management of heavy metals in urban environments.

Abstract Background Lactate, a glycolytic metabolite mainly produced in muscles, has been suggested to regulate myoblast differentiation, although the underlying mechanism remains elusive. Recently, lactate‐mediated histone lactylation is identified as a novel epigenetic modification that promotes gene transcription. Methods We used mouse C2C12 cell line and 2‐month‐old male mice as in vitro and in vivo models, respectively. These models were treated with lactate to explore the biological function and latent mechanism of lactate‐derived histone lactylation on myogenic differentiation by quantitative real‐time PCR, western blotting, immunofluorescence staining, chromatin immunoprecipitation, cleavage under targets and tagmentation assay and RNA sequencing. Results Using immunofluorescence staining and western blotting, we proposed that lactylation might occur in the histones. Inhibition of lactate production or intake both impaired myoblast differentiation, accompanied by diminished lactylation in the histones. Using lactylation site‐specific antibodies, we demonstrated that lactate preferentially increased H3K9 lactylation (H3K9la) during myoblast differentiation (CT VS 5, 10, 15, 20, 25 mM lactate treatment, P = 0.0012, P = 0.0007, and the rest of all P < 0.0001). Notably, inhibiting H3K9la using P300 antagonist could block lactate‐induced myogenesis. Through combined omics analysis using cleavage under targets and tagmentation assay and RNA sequencing, we further identified Neu2 as a potential target gene of H3K9la. IGV software analysis (P = 0.0013) and chromatin immunoprecipitation‐qPCR assay (H3K9la %Input, LA group = 9.0076, control group = 2.7184, IgG = 0.3209) confirmed that H3K9la is enriched in the promoter region of Neu2. Moreover, siRNAs or inhibitors against Neu2 both abrogated myoblast differentiation despite lactate treatment, suggesting that Neu2 is required for lactate‐mediated myoblast differentiation. Conclusions Our findings provide novel understanding of histone lysine lactylation, suggesting its role in myogenesis, and as potential therapeutic targets for muscle diseases.

Refractory Black carbon (rBC) emitted from the combustion of biomass and fossil fuels plays an important role in the climate system. In this study, we established a record of the rBC concentration spanning 1932-2013 from an ice core retrieved from the Chongce ice cap of the West Kunlun Mountains in the western Tibetan Plateau. The record showed an increasing trend since the 1980s. The mean concentration of rBC was 2.66 ng g-1 before 1980 and 5.33 ng g-1 since 1980. The significant increase since the 1980s was very different from similar records from European ice cores. An analysis of atmospheric circulation and backward trajectories suggested that former USSR, the Middle East, and South Asia were the most likely source regions for the rBC deposited at the Chongce ice cap. This conclusion was also supported by the historical emission data in these regions. Phase analysis indicated that high rBC concentrations were closely associated with drought-induced biomass burning in the rBC source regions at the decadal timescale. These findings suggested that anthropogenic emissions controlled the long-term rBC trend, while the peak phases were caused from an increase of biomass burning.

T cell intracellular antigen 1 related protein (TIAR), an RNA-binding protein (RBP), regulates pre-messenger RNA (pre-mRNA) alternative splicing, has been suggested to affect the maturation of primordial germ cells and early mouse embryo development. However, the underlying mechanism remains elusive. In this study, we revealed that TIAR was primarily located in the nucleus at the 2-cell stage embryo, accompanied by highly active transcription. Using immunofluorescence staining and western blotting, we first described the localization and expression level of TIAR during the whole period of oocyte matured and embryogenesis. Knocked down of TIAR could significantly inhibit transcribed and blocked the early mouse embryo development. Combined with RNAP II inhibitor and pre-RNA splicing inhibitor treatment, we further supposed that TIAR might affect transcription at 2-cell via regulating pre-mRNA splicing, and then regulate early mouse embryo development. Collectively, our results provided a novel and potential understanding of TIAR in embryogenesis, suggesting TIAR is required for transcription and embryonic development.

Mines are an important weapon in modern naval warfare, playing a crucial role in the execution of maritime blockade tasks by armed forces. Facing potential future maritime armed conflicts, how to implement a maritime blockade using mines and how to counter enemy mines will be essential challenges in naval battles. A thorough understanding and mastery of the legal issues involved in mine warfare is a necessary prerequisite for the scientific use of mines in blockades. Additionally, conducting operations strictly in accordance with the law helps belligerents gain more international public opinion support during maritime blockade operations. This paper mainly focuses on the international legal rules related to the use of mines in maritime blockades, exploring legal issues that may arise during blockade missions and proposing targeted countermeasures and suggestions.