Hydrodynamic reconstruction driven by China’s national water network has been widely implemented to balance water resources and improve water quality, but it also poses emerging challenges to the stability of carbon cycling at aquatic critical zone interfaces in water diversion rivers. However, the related regulatory pathways in riverine carbon biogeochemistry remain poorly understood. Here, we used controlled mesocosms manipulating both water depth and flow velocity to reveal how hydrologic controls imposed by hydrodynamic reconstruction regulate carbon transformations and emissions. Results showed that depth primarily governed ionic strength, whereas flow velocity modulated oxygen dynamics, together shaping the microenvironmental conditions that regulate carbon substrate partitioning. Deeper water with slow flow created reducing environments that enhanced microbial biomass carbon, increased Carbon Use Efficiency (CUE), stimulated methanogenesis, and lowered the net warming potential. In contrast, higher flow velocity strengthened oxygen delivery, stimulated aerobic respiration and carbon mineralization, leading to CO2-dominated emissions, rapid depletion of labile carbon, and an intensified warming potential. CUE emerged as a central mediator linking hydrologic conditions to divergent CO2 and CH4 emission pathways, revealing a hydrologic-biogeochemical mechanism underlying carbon cycling in water diversion rivers. The increased water depth enhanced microbial carbon retention and reduced CO2 flux by 25.65%, while shifting CH4 from a net sink to a net source. In contrast, the increased flow velocity accelerated labile carbon loss, increased CO2 flux by 89.04%, and reduced CH4 fluxes by 65.06%. These findings provide a new ecological perspective for evaluating the environmental benefits of national water network construction and offer scientific guidance for optimizing hydrodynamic management to support China’s carbon peaking and carbon neutrality goals.

The global prevalence of antibiotic resistance genes (ARGs) has aroused increasing concern due to its threat to ecological security and human health. Although biochar has been widely used for pollution remediation including ARGs, little is known its regulation on antibiotics and ARGs propagation under riparian zones, where undergo frequent occurrence of dry and wet alternations (DWA) caused by water-level fluctuation. Therefore, this study investigated the regulative effects of biochar through different addition approaches on ARGs spread in riparian zone sediments. Under DWA, the presence of biochar (2 % w/w) inhibited microbial diversity and function expression, especially for tiled biochar. In addition, compared with DWA, the tiled biochar decreased ARGs abundance by 45.36 %, while the well-mixed increased that by 269.02 %. The ARGs abundance in sediments was positively correlated with mobile genetic element abundance (R2=0.996, p < 0.05), indicative of high horizontal gene transfer potential of ARGs. Metabolomics revealed that both DWA and biochar significantly altered microbial metabolism pathways in sediments, involving sulfur metabolism and histidine metabolism. Furthermore, ARGs propagation in riparian zones may be dominantly driven by MGEs, especially by transposases and integrase. These findings highlight the tiled biochar remediation effects on ARGs in riparian zones under DWA caused by global warming.

Mixed legacy and emerging per- and polyfluoroalkyl substances (PFASs) are commonly found in soil and dust; however, the potential toxicity of PFAS mixtures (mPFASs) in insects is unknown. Using 16S rRNA gene sequencing and transcriptome sequencing (RNA-Seq), we evaluated the adverse effects of mPFASs on silkworms, a typical lepidopteran insect. After exposure to mPFASs, the silkworm midgut was enriched with high levels of PFASs, which induced histopathological changes. The composition of the midgut microbiota was significantly affected by mPFAS exposure, and functional predictions revealed significant disruption of some metabolic pathways. RNA-seq analysis revealed that mPFASs significantly changed the transcription profiles. Functional enrichment analysis of the differentially expressed genes also revealed that biological processes related to metabolic pathways and the digestive system were significantly affected, similar to the results of the gut microbiota analysis, suggesting that mPFAS exposure had an adverse effect on the metabolic function of silkworms and may further affect their normal growth. Finally, the significant correlation between abundance changes in the gut microbiota and metabolism/digestion-related genes further highlighted the role of the gut microbiota in mPFAS-related processes affecting the metabolic functions of silkworms. To our knowledge, this study is the first to evaluate the toxic effects of mPFASs in insects and provide basic data for further PFAS toxicity investigations in insects and comprehensive ecological risk assessments of mPFASs.

Conventional wastewater treatment methods cannot completely remove the ultraviolet (UV) filters or dissolved organic matter. The transformation characteristics of these substances during chlorination disinfection and the varying species-specific toxicities of their combinations remain unclear. Here, Daphnia magna and zebrafish were exposed to benzophenone-3 (BP-3) and humic acid (HA) before and after chlorination disinfection. The results from chemical indicators showed that chlorination treatment decreased UV254 values and changed the intensity of parallel factors in three-dimensional fluorescence. Based on chemical analysis, the chlorine concentration and chlorination time for the toxicity experiments were set at 5 mg/L and 6 h, respectively. Exposure to HA and BP-3 before and after chlorination decreased the heart rate (by 1.37-28.12 %) in both species. However, species-specific responses, including survival rate, swimming distance, and expression of genes related to neurodevelopment, growth, and oxidative stress, were induced by chlorination. Chlorination reduced the impact of HA exposure but worsened the effects of HA and BP-3 co-exposure on D. magna. However, in zebrafish, the toxic effects intensified in most of the exposure groups after chlorination. Correlation analysis showed that the parallel factors of three-dimensional fluorescence were correlated with toxic effects on zebrafish, whereas UV254 was more significantly correlated with toxic effects on D. magna. This study provides insights into the combined toxicity of UV filters and dissolved organic matter in different aquatic organisms during chlorination, which is useful for risk control and optimization of the chlorination process.

The coexistence of emerging pollutants and dissolved organic matter in wastewater complicates the transformation and generation of disinfection byproducts (DBPs) during chlorination treatment, which is essential for effective water quality evaluation and chlorination optimization. This study used fluoxetine (FLX) and humic acid (HA) as representative substances to analyze changes in their chemical characteristics and zebrafish embryonic developmental toxicity under different chlorination conditions. The analysis of the fluorescence characteristics and Fourier transform ion cyclotron resonance mass spectrometry indicated that chlorination treatment increased the aromatic compound content of the HA solution. FLX addition further increased the presence of aromatic ring structures and oxidized molecules, resulting in the formation of numerous Cl-DBPs with highly unsaturated and phenolic structures. Moreover, different responses in zebrafish embryo development and behavior were found with FLX, HA, and FLX + HA exposures. Cardiotoxicity was linked to changes in the concentration of cTn-I protein and expression of various genes. Prolonged chlorination conditions showed higher toxicities. Correlation analysis found a weak relation between chemical indicators and toxicity data, indicating that both analysis methods need to be considered when analyzing the impact of the chlorination. Further, a combination of chemical analyses and toxicity tests revealed that the FLX + HA solution with chlorination conditions of 3 mg/L for 30 min had lower chemical and toxic effects in this experiment. This study provides valuable scientific insights for the safe discharge of chlorinated water containing FLX and dissolved organic matter, as well as guidance for optimizing chlorination parameters in wastewater treatment.

Benzophenone-3 (BP-3) is a commonly used ultraviolet absorber that has the potential to accumulate in organisms, leading to toxicity. Benzophenone-8 (BP-8) is one of the major metabolites of BP-3. In this study, zebrafish were exposed to different concentrations of BP-3 and BP-8 (1 μg/L, 30 μg/L, and 300 μg/L) to investigate their accumulation and toxic effects in various tissues, including zebrafish brain, gut, and liver. The analysis focused on neurotoxicity, oxidative damage, inflammation, and gene expressions. The results showed that both BP-3 and BP-8 accumulated in the tissues, with the highest concentration observed in the gut, followed by the liver and brain. BP-8 exhibited a stronger ability to accumulate. In the brain, exposure to 1 μg/L of BP-3 and BP-8 promoted cortisol production, while higher exposures (30 μg/L and 300 μg/L) inhibited acetylcholinesterase activity and suppressed cortisol production. In the gut, both BP-3 and BP-8 exposures disrupted oxidative stress, inflammatory immunity, and apoptosis functions. In the liver, BP-3 and BP-8 affected hepatic metabolism, oxidative stress, apoptosis, and inflammatory immunity. Comparing gene expression in the brain, gut, and liver, it was found that BP-3 and BP-8 had a lower effect on gene expression in the brain, while the effect on the gut and liver was significantly higher. BP-8 generally had a higher effect than BP-3, which aligns with the observed accumulation pattern. These findings provide valuable insights for the risk assessment of BP-3 and BP-8 in the aquatic environment.

Microplastics (MPs) can adsorb and desorb organic pollutants, which may alter their biotoxicities. Although the toxicity of perfluorooctane sulfonate (PFOS) and its alternative 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) to organisms has been reported, the comparative study of their combined toxic effects with MPs on aquatic organisms is limited. In this study, adult female zebrafish were exposed to 10 μg/L PFOS/F-53B and 50 μg/L MPs alone or in combination for 14 days to investigate their single and combined toxicities. The results showed that the presence of MPs reduced the concentration of freely dissolved PFOS and F-53B in the exposure solution but did not affect their bioaccumulation in the zebrafish liver and gut. The combined exposure to PFOS and MPs had the greatest impact on liver oxidative stress, immunoinflammatory, and energy metabolism disorders. 16S rRNA gene sequencing analysis revealed that the combined exposure to F-53B and MPs had the greatest impact on gut microbiota. Functional enrichment analysis predicted that the alternations in the gut microbiome could interfere with signaling pathways related to immune and energy metabolic processes. Moreover, significant correlations were observed between changes in gut microbiota and immune and energy metabolism indicators, highlighting the role of gut microbiota in host health. Together, our findings demonstrate that combined exposure to PFOS/F-53B and MPs exacerbates liver immunotoxicity and disturbances in energy metabolism in adult zebrafish compared to single exposure, potentially through dysregulation of gut microbiota.

Benzophenone-3 (BP-3) as one of frequently used organic UV filters has been considered an emerging pollutant due to its toxicities. Benzophenone-8 (BP-8) is one of the main metabolites of BP-3 in organisms. Current reports show that BP-8 may be more toxic than BP-3. However, difference of their toxicities on embryonic development has rarely been reported. In this study, zebrafish embryos were chosen as the target organism to explore the developmental toxicities of BP-3 and BP-8. Non-targeted metabolomic analysis was performed to compare their modes of action. Results showed that BP-8 exposures led to higher bioaccumulation and lower hatching rate of zebrafish larvae than BP-3. Both BP-8 and BP-3 exposures caused behavioral abnormalities of zebrafish larvae, but no significant difference was found between them. At the metabolome level, 1 mu g/L BP-3 and 1 mu g/L BP-8 exposures altered neuroactive ligand-receptor interaction pathway and FoxO signaling pathway, respectively, which might be involved in the abnormal behaviors in zebrafish larvae. For higher exposure groups (30 and 300 mu g/L), both BP-3 and BP-8 exposures changed metabolism of cofactors and vitamins of zebrafish larvae. Exposure of BP-3 altered the metabolism by pantothenate and CoA biosynthesis pathway, while BP-8 exposure changed riboflavin metabolism and folate biosynthesis. The above results indicated different modes of action of BP-3 and BP-8 in zebrafish embryonic development. This study sheds new light to biological hazards of BP-3 due to its metabolism in aquatic organisms.

Hexafluoropropylene oxide dimer acid (HFPO-DA) and hexafluoropropylene oxide trimer acid (HFPO-TA) are considered as alternatives to perfluorooctanoic acid (PFOA). In this study, zebrafish were exposed to different concentrations of PFOA, HFPO-DA, and HFPO-TA (5 & mu;g/L and 500 & mu;g/L), and the toxic effects on oxidative damage, inflammation, and cell apoptosis in the gut were compared. Additionally, changes in gut metabolome profiles and microbial community structure were analyzed. The results revealed that exposures to HFPO-DA and HFPO-TA led to lower levels of oxidative damage compared to PFOA exposure. However, all three treatments had comparable effects on inflammation and apoptosis. The main biological pathways affected by all three exposures were lipid metabolism, nucleotide metabolism, amino acid metabolism, and environmental information processing. The effects on metabolome profiles were much higher for HFPO-DA and HFPO-TA compared to PFOA at a concentration of 5 & mu;g/L. At a concentration of 500 & mu;g/L, HFPO-DA and HFPO-TA showed similar effects to PFOA. This study also examined the Pearson correlations between gut microbiota and the toxic effects mentioned above. The abundance of specific apoptosis-related genera differed among the three target chemicals, suggesting they may act differently in inducing apoptosis. The correlations between HFPO-DA and HFPO-TA were mostly similar, which helps explain the similar effects observed in their respective treatment groups on metabolic profiles. Overall, this study indicates that HFPO-DA and HFPO-TA may not be safe alternatives to PFOA and provides valuable insights into their toxic effects and risk assessment in water environments.

为明确珠江流域雨季特征及ENSO(El Ni?o-Southern Oscillation)对雨季降雨的影响,利用多尺度滑动T检验法划分了珠江流域雨季,阐明CPW(Central Pacific Warming)、EPC(Eastern Pacific Cooling)、EPW(Eastern Pacific Warming)、传统ENSO和ENSO Modoki五种ENSO类型在发展期和衰减期对珠江流域雨季降雨产生的影响及其物理归因.研究结果表明:在EPC发展期和衰减期,珠江流域的雨季降雨显著减小;ENSO和ENSO Modoki在发展期更容易引发洪涝,而衰减期更容易引起干旱;更强的印度洋季风和北太平洋西部的反气旋会为珠江流域雨季带来更多的降雨.

Hexafluoropropylene oxide dimer acids (HFPO-DA) and hexafluoropropylene oxide trimer acids (HFPO-TA) are alternatives to perfluorooctanoic acid (PFOA). However, little information on the comparison of their toxicities is available. Here, zebrafish embryos were exposed to PFOA, HFPO-DA, and HFPO-TA with exposure concentra-tions of 5 and 500 mu g/L. Behavioral abnormal, enzyme activities and gene expression profiles in zebrafish em-bryos were determined. Results showed that exposure to PFOA and its alternatives increased heart rates and inhibited locomotor activity of zebrafish embryos. Further, their exposures changed the enzyme activities (acetylcholinesterase and oxidative stress-related enzymes), ATP content, and expressions of genes related to hypothalamic-pituitary-thyroid (HPT) axis, apoptosis, and lipid metabolism. Comparison analyses found that PFOA, HFPO-TA, and HFPO-DA exposures induced different effects on the embryonic development of zebrafish, which indicates the different modes of action. The HFPO-DA exposure induced specific effects on the disorder of lipid metabolism, HPT axis, and neurodevelopment. The HFPO-TA exposure also induced different effects from the PFOA exposure, which focused on lipid metabolism. The current data shows that the HFPO-DA and HFPO-TA might not be safe alternatives to PFOA. This study provides a new understanding of the biological hazards of PFOA alternatives in aquatic organisms, which can guide their usage.

Tetracycline antibiotics (TCs) and heavy metals are commonly used in livestock and poultry farming, leading to their coexistence in the aquatic environment. This coexistence causes combined toxicity to aquatic organisms. Here, zebrafish embryos were exposed to chlortetracycline (CTC), oxytetracycline (OTC), zinc chloride (ZnCl2), and their combinations for 120 h to evaluate their adverse effects on the growth, antioxidant system, immune system, and endocrine system during the early stage of life. OTC/ZnCl2 combined exposure significantly reduced the body weight, whereas the TCs/ZnCl2 combination significantly increased the heart rate of zebrafish larvae, suggesting growth impairment induced by TCs and ZnCl2. Further, combined groups showed more prominent toxicity to the antioxidant system than single groups, as revealed by related levels of enzyme activity and gene expression. In addition, the levels of most pro-inflammatory genes were downregulated, and those of NF-κB-related genes were upregulated in all treatment groups, indicating an immunosuppressive response and the potential role of NF-κB signaling, while the combined treatment was not more toxic than TCs or ZnCl2 alone. Similarly, hormone and endocrine related gene levels were determined. Although both single and combined exposures caused certain endocrine-disrupting effects, the combined exposure did not result in higher toxicity than a single exposure. Our findings showed that a mixture of TCs and ZnCl2 might exert greater toxic effects as compared to a single compound on some systems, providing fundamental data on the toxic effects of single and combined TC and ZnCl2 exposure on aquatic organisms, although studies are needed to explore the underlying mechanisms.

Water sources are an indispensable resource for human survival. Monitoring the pollution status of the surrounding environment is necessary to protect water sources. Research on the environmental matrix of deep eutectic solvents (DESs) has expanded rapidly because of their high extraction efficiency for various target analytes, controllable synthesis, and versatile structure. Following the synthesis of hydrophobic deep eutectic solvents (HDESs), their application in aqueous matrices broadened greatly. The present review conducted a survey on the pollutant extraction methods based DESs in environmental matrices from two aspects, application methods and matrix types; discussed the potential risk of DESs to the environment and future development trends; and provided some references for researchers to choose DES-based extraction methods for environmental research.

利用1960-2020年长江流域126个气象站点的降雨数据,采用滑动t检验法确定长江流域各站点的雨季起讫时间和雨季降雨量的时空分布规律,揭示了长江流域雨季特征变化与海表温度及大气环流的相关性.结果表明:长江流域的雨季开始时间、结束时间以及雨季降雨量具有明显的年代际和空间变化特征.从空间分布上看,雨季特征具有从东南向西北递减的带状分布规律;从时间变化规律上看,雨季特征具有明显的波动性.雨季特征的变化规律与海表温度及太平洋北部的反气旋密切相关,升高的海表温度会导致长江流域雨季开始时间延迟、结束时间提前以及降雨量减小,研究结果对掌握长江流域雨季特征与海表温度的遥相关性具有重要意义.

在泸渝段航道整治工程中,开辟神背嘴滩右槽为主航槽,整治初期效果显著.针对长江上游船舶大型化、神背嘴滩十余年河床演变后的航道条件适应性问题,基于滩槽演变、浅区变化、分流比、流速比降、与船舶发展和航道规划适应性等方面对神背嘴滩航道条件进行分析评价.评价认为航槽有所回淤.鉴于各水位期均存在坡陡流急的现象,提出特殊时期扩大泄水断面、适当提高部分整治建筑物高程的维护措施.

莲石滩是长江上游著名的复杂险滩,具有浅、 险、 急等复合碍航特性.基于前期碍航特性、 成滩原因和治理思路等研究成果,结合整治目标,对鱼鳅石浅滩和关刀碛急滩分别采用"疏槽维稳"和"扩枯稳中"的整治思路,根据设计航槽走向的不同提出两组方案进行模型试验.结果表明,两组方案均可基本解决碍航问题,方案2在顺应河势、 航线选择、整治效果方面更优.

叙渝段航道整治建筑物坝面维修受上游金沙江、 岷江枢纽电站的非恒定流影响明显.基于近年李庄、 朱沱两站逐时水位资料,分析了两站水位变化特征.根据低水位集中、 日变幅最小的原则提出了宜宾—合江、 合江—重庆河段航道整治建筑物坝面维修的最佳施工时间,为保证坝面的质量,可适当减小坝面厚度或采取分段施工的方法.

PURPOSE:To evaluate dentists' knowledge and practice of revascularization in Shanghai.METHODS:Using multistage, cluster and random sampling method, 5 districts from Shanghai urban and suburban areas were randomly selected, covering class-three and class-two hospitals, dental center, private hospitals and clinics, and 3 class-three authoritative dental special hospitals (nonrandom). A questionnaire survey was conducted among the endodontists, pedodontists and general dentists. SAS 9.13 software package was used for data analysis.RESULTS:A total of 834 dentists were investigated, and 588 valid questionnaires (75.3%) were collected. 401 (68.2%) dentists were familiar with revascularization, 20% of them treated patients with revascularization. The most common source of learning revascularization was continuing dental education (33.3%) and 85.8% dentists showed interest in revascularization. The most important reason for not using revascularization was unfamiliar with the operational procedure (41.5%).CONCLUSIONS:The middle-aged endodontic and pediatric specialists with higher education have better understanding and motion to apply revascularization, and are more interested in continuing dental education. In continuing education courses, lectures of revascularization with practical training should be increased, in order to promote revascularization application in dental practice.

利用小基线集合成孔径雷达干涉测量技术,对覆盖天水市区的17景ALSO-PALSAR影像数据进行干涉处理,提取该区域2007年2月9日-2011年2月20日的地表年平均变形速率分布图,监测结果显示主城区处于基本稳定状态,变形区主要集中在市区周边区域,如皂郊镇、太京镇以及罗峪沟等地,主要的地表变形类型有滑坡、危险边坡和地面沉降等,平均变形速率为-34.0～41.6 mm/a.对研究区内6个变形区域进行实地调查并分析成因,验证了InSAR技术高精度、观测覆盖范围广的特点以及在开展区域地质灾害识别应用中的准确度,为区内地质灾害监测选点和防治提供科学依据.