Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during...Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during the processing of mining wastewater and leaching of mine tailings.Owing to their excellent physicochemical properties,cementitious materials are widely used for the solidification/stabilization of heavy metals,immobilizing heavy metals via two distinct mechanisms.Physically,their favorable characteristics,including high mechanical strength,low porosity,and durable matrix,create effective barriers.Chemically,the alkaline environment facilitates the precipitation of metal hydroxides/carbonates.Conversely,hydration products(calcium silicate hydrate gels and ettringite)contribute to immobilization through adsorption and physical encapsulation.This study systematically investigated the migration mechanisms of heavy metal contaminants in mine tailings;further,it elucidated the multifaceted immobilization pathways of cementitious materials,which involve synergistic adsorption,precipitation,and encapsulation by hydration products combined with homocrystalline substitution.A comprehensive analysis indicated that cementitious materials significantly reduced the mobility and bioavailability of heavy metals.Nonetheless,their long-term stability and potential environmental impact require further investigation.This study aims to provide theoretical support for environmental management and sustainable resource utilization,and to explore the broader application potential of cementitious technology for heavy metal stabilization,thereby establishing a theoretical foundation for future research on heavy metals in low-cement solidified/stabilized tailings.展开更多
Background:The association between delayed surgery and survival outcomes in locally advanced rectal cancer patients with a poor response to neoadjuvant chemoradiotherapy(nCRT)remains unclear.This study aimed to determ...Background:The association between delayed surgery and survival outcomes in locally advanced rectal cancer patients with a poor response to neoadjuvant chemoradiotherapy(nCRT)remains unclear.This study aimed to determine the optimal timing of surgery following nCRT in these patients and to explore the association between delayed surgery and survival outcomes.Methods:Restricted cubic spline curves were used to determine the optimal timing of surgery for patients with a poor response to nCRT(ypT2-4N0 or ypTxN+).The patients were divided into two groups:the early surgery group and the delayed surgery group.Propensity score matching(PSM)analysis was employed to reduce the selection bias and survival analysis was conducted to assess the survival differences.Immunostaining of post-operative specimens was performed to investigate whether the difference in survival was associated with the CD8^(+) T-cell density in the tumor.Results:A total of 583 patients were enrolled in this study.The optimal timing for surgery was determined to be 9 weeks after nCRT.In PSM analysis,delayed surgery was associated with worse disease-free survival(63.0%vs 76.3%at 5 years,53.0%vs 76.3%at 10 years;P=0.003)and cancer-specific survival(72.9%vs 85.5%at 5 years,60.1%vs 81.8%at 10 years;P=0.001).Immunostaining analysis showed that longer waiting times were associated with decreased CD8^(+) T-cell density in tumors(P=0.017).Conclusions:Patients who had a poor tumor response after nCRT,detected by using magnetic resonance imaging restaging or other assessments,need timely radical surgery without delay.展开更多
Microplastics(MPs),recognized as an emerging global environmental concern,have been extensively detected worldwide,with specific attention directed towards the Yangtze River Estuary(YRE)and East China Sea(ECS)regions....Microplastics(MPs),recognized as an emerging global environmental concern,have been extensively detected worldwide,with specific attention directed towards the Yangtze River Estuary(YRE)and East China Sea(ECS)regions.Despite their critical research significance,there remains a knowledge gap concerning the distribution of MPs in the benthic layer within this area,particularly regarding interactions governing their occurrence.Here we illuminate the distribution of MPs within the benthic layer and unravel the intricate interplay between bottom water and sediment in the YRE and ECS.We find that MPs are notably more abundant in bottom water,ranging from 8 to 175 times higher than in surface water.These MPs predominantly consist of polyester fibers,exhibit a size range between 0.5 and 5.0 mm,and display distinct coloration.Co-occurrence network analysis and Principal Coordinate Analysis confirm a robust correlation between MPs in bottom water and sediment,signifying the pivotal role of bottom water in mediating the distribution and transportation of MPs within the benthic layer.Furthermore,a positive correlation between MPs in sediment and bottom water turbidity underscores the impact of surface sediment resuspension and upwelling on MPs distribution.This study clarifies the intricate interactions within the benthic layer and highlights the crucial role of bottom water as a mediator in the vertical distribution of MPs,advancing our understanding of the“source-to-sink”transport processes governing MPs within water-sediment systems.展开更多
基金supported by the National Natural Science Foundation of China(No.52374121)the Henan Province Science and Technology Research and Development Joint Fund,China(No.235200810016)the National Key Research and Development Program,China(No.2023YFC2907203).
文摘Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during the processing of mining wastewater and leaching of mine tailings.Owing to their excellent physicochemical properties,cementitious materials are widely used for the solidification/stabilization of heavy metals,immobilizing heavy metals via two distinct mechanisms.Physically,their favorable characteristics,including high mechanical strength,low porosity,and durable matrix,create effective barriers.Chemically,the alkaline environment facilitates the precipitation of metal hydroxides/carbonates.Conversely,hydration products(calcium silicate hydrate gels and ettringite)contribute to immobilization through adsorption and physical encapsulation.This study systematically investigated the migration mechanisms of heavy metal contaminants in mine tailings;further,it elucidated the multifaceted immobilization pathways of cementitious materials,which involve synergistic adsorption,precipitation,and encapsulation by hydration products combined with homocrystalline substitution.A comprehensive analysis indicated that cementitious materials significantly reduced the mobility and bioavailability of heavy metals.Nonetheless,their long-term stability and potential environmental impact require further investigation.This study aims to provide theoretical support for environmental management and sustainable resource utilization,and to explore the broader application potential of cementitious technology for heavy metal stabilization,thereby establishing a theoretical foundation for future research on heavy metals in low-cement solidified/stabilized tailings.
基金supported by Sun Yat-sen University 5010 research fund[201313]Guangdong Basic and Applied Basic Research Foundation[grant no.2021A1515010096 and 2023A1515010243]+1 种基金Sun Yat-sen University Basic Research Fund[grant no.19ykpy180]Science and Technology Projects in Guangzhou[grant no.2023A04J1763].
文摘Background:The association between delayed surgery and survival outcomes in locally advanced rectal cancer patients with a poor response to neoadjuvant chemoradiotherapy(nCRT)remains unclear.This study aimed to determine the optimal timing of surgery following nCRT in these patients and to explore the association between delayed surgery and survival outcomes.Methods:Restricted cubic spline curves were used to determine the optimal timing of surgery for patients with a poor response to nCRT(ypT2-4N0 or ypTxN+).The patients were divided into two groups:the early surgery group and the delayed surgery group.Propensity score matching(PSM)analysis was employed to reduce the selection bias and survival analysis was conducted to assess the survival differences.Immunostaining of post-operative specimens was performed to investigate whether the difference in survival was associated with the CD8^(+) T-cell density in the tumor.Results:A total of 583 patients were enrolled in this study.The optimal timing for surgery was determined to be 9 weeks after nCRT.In PSM analysis,delayed surgery was associated with worse disease-free survival(63.0%vs 76.3%at 5 years,53.0%vs 76.3%at 10 years;P=0.003)and cancer-specific survival(72.9%vs 85.5%at 5 years,60.1%vs 81.8%at 10 years;P=0.001).Immunostaining analysis showed that longer waiting times were associated with decreased CD8^(+) T-cell density in tumors(P=0.017).Conclusions:Patients who had a poor tumor response after nCRT,detected by using magnetic resonance imaging restaging or other assessments,need timely radical surgery without delay.
基金supported by the National Natural Science Foundation of China(No.41977329,No.41771513,No.42049903,No.42277403)the Natural Science Foundation of Guangdong Province(No.2021B1515020041)for financial supportWe thank the crews of the ZheyukeⅡfor their hard work at sea and the scientists who joined the cruise to help in data collection.
文摘Microplastics(MPs),recognized as an emerging global environmental concern,have been extensively detected worldwide,with specific attention directed towards the Yangtze River Estuary(YRE)and East China Sea(ECS)regions.Despite their critical research significance,there remains a knowledge gap concerning the distribution of MPs in the benthic layer within this area,particularly regarding interactions governing their occurrence.Here we illuminate the distribution of MPs within the benthic layer and unravel the intricate interplay between bottom water and sediment in the YRE and ECS.We find that MPs are notably more abundant in bottom water,ranging from 8 to 175 times higher than in surface water.These MPs predominantly consist of polyester fibers,exhibit a size range between 0.5 and 5.0 mm,and display distinct coloration.Co-occurrence network analysis and Principal Coordinate Analysis confirm a robust correlation between MPs in bottom water and sediment,signifying the pivotal role of bottom water in mediating the distribution and transportation of MPs within the benthic layer.Furthermore,a positive correlation between MPs in sediment and bottom water turbidity underscores the impact of surface sediment resuspension and upwelling on MPs distribution.This study clarifies the intricate interactions within the benthic layer and highlights the crucial role of bottom water as a mediator in the vertical distribution of MPs,advancing our understanding of the“source-to-sink”transport processes governing MPs within water-sediment systems.
