Per-and polyfluorinated alkyl substances(PFASs) are commonly used in industrial processes and daily life products.Because they are persistent, they accumulate in the environment, wildlife and humans.Although many stud...Per-and polyfluorinated alkyl substances(PFASs) are commonly used in industrial processes and daily life products.Because they are persistent, they accumulate in the environment, wildlife and humans.Although many studies have focused on two of the most representative PFASs, PFOS and PFOA, the potential toxicity of short-chain PFASs has not yet been given sufficient attention.We used a battery of assays to evaluate the toxicity of several four-carbon and six-carbon perfluorinated sulfonates and carboxyl acids(PFBS,PFHxS, PFBA and PFHxA), with a human mesenchymal stem cell(hMSC) system.Our results demonstrate significant cyto-and potential developmental toxicity for all the compounds analyzed, with shared but also distinct mechanisms of toxicity.Moreover, the effects of PFBS and PFHxS were stronger than those of PFBA and PFHxA, but occurred at higher doses compared to PFOS or PFOA.展开更多
To protect the wellbeing of research animals,certain non-invasive measures are in increasing need to facilitate an early diagnosis of health and toxicity.In this study,feces specimen was collected from adult zebrafish...To protect the wellbeing of research animals,certain non-invasive measures are in increasing need to facilitate an early diagnosis of health and toxicity.In this study,feces specimen was collected from adult zebrafish to profile the metabolome fingerprint.Variability in fecal metabolite composition was also distinguished as a result of aging,perfluorobutanesulfonate(PFBS)toxicant,and fecal transplantation.The results showed that zebrafish feces was very rich in a diversity of metabolites that belonged to several major classes,including lipid,amino acid,carbohydrate,vitamin,steroid hormone,and neurotransmitter.Fecal metabolites had functional implications to multiple physiological activities,which were characterized by the enrichment of digestion,absorption,endocrine,and neurotransmission processes.The high richness and functional involvement of fecal metabolites pinpointed feces as an abundant source of diagnostic markers.By comparison between young and aged zebrafish,fundamental modifications of fecal metabolomes were caused by aging progression,centering on the neuroactive ligand-receptor interaction pathway.Exposure of aged zebrafish to PFBS pollutant also significantly disrupted the metabolomic structure in feces.Of special concern were the changes in fecal hormone intermediates after PFBS exposure,which was concordant with the in vivo endocrine disrupting effects of PFBS.Furthermore,itwas intriguing that transplantation of young zebrafish feces efficientlymitigated the metabolic perturbation of PFBS in aged recipients,highlighting the health benefits of therapeutic strategies based on gut microbiota manipulation.In summary,the present study provides preliminary clues to evidence the non-invasive advantage of fecal metabolomics in the early diagnosis and prediction of physiology and toxicology.展开更多
简述了基于ROACH和Xilinx System Generator平台的接收机数字后端系统的设计与实现。介绍了Zoom-PFB算法原理,讨论了该算法的核心部分低通滤波和抽取的现场可编程门阵列(Field-Programmable Gate Array,FPGA)实现。针对谱线观测局部高...简述了基于ROACH和Xilinx System Generator平台的接收机数字后端系统的设计与实现。介绍了Zoom-PFB算法原理,讨论了该算法的核心部分低通滤波和抽取的现场可编程门阵列(Field-Programmable Gate Array,FPGA)实现。针对谱线观测局部高精度分辨率的需要,给出了将400 MHz带宽分为带宽25 MHz的16个通道,对其中任一通道做通道数为6 k、频率分辨率为4 k Hz的频谱细化系统的具体设计方案。在实验室条件下,对该数字后端的性能进行了分析和测试,并以4.5 m口径X/Y结构天线进行银道面中性氢谱线观测检验其应用效果,验证了方案的可行性。展开更多
Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terep...Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terephthalic acid-modified WO_(3) was prepared and further used as photocatalysts for perfluorobutane sulfonate(PFBS)degradation.In this design,terephthalic acid was used as an electron recombination center and heterojunction mediator,which effectively enhances the migration ability of electron-hole pairs and the physicochemical stability of the catalyst.In addition,in situ synthesis of CeO_(2)onto the WO_(3) surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO_(2)agglomeration.As a result,the CeO_(2)@WO_(3) photocatalyst exhibits excellent PFBS degradation ability(94%for CeO_(2)@WO_(3) vs.19%for CeO_(2)).After the fifth cyclic degradation experiment,the CeO_(2)@WO_(3) photocatalyst still maintains stable degradation efficiency.Furthermore,the reaction mechanism of the PFBS in CeO_(2)@WO_(3) photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry(LC-MS)technique.This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO_(2)@WO_(3) photocatalysts possess a promising prospect for degrading PFBS pollutants.展开更多
Multi-constrained pipes conveying fluid,such as aircraft hydraulic control pipes,are susceptible to resonance fatigue in harsh vibration environments,which may lead to system failure and even catastrophic accidents.In...Multi-constrained pipes conveying fluid,such as aircraft hydraulic control pipes,are susceptible to resonance fatigue in harsh vibration environments,which may lead to system failure and even catastrophic accidents.In this study,a machine learning(ML)-assisted weak vibration design method under harsh environmental excitations is proposed.The dynamic model of a typical pipe is developed using the absolute nodal coordinate formulation(ANCF)to determine its vibrational characteristics.With the harsh vibration environments as the preserved frequency band(PFB),the safety design is defined by comparing the natural frequency with the PFB.By analyzing the safety design of pipes with different constraint parameters,the dataset of the absolute safety length and the absolute resonance length of the pipe is obtained.This dataset is then utilized to develop genetic programming(GP)algorithm-based ML models capable of producing explicit mathematical expressions of the pipe's absolute safety length and absolute resonance length with the location,stiffness,and total number of retaining clips as design variables.The proposed ML models effectively bridge the dataset with the prediction results.Thus,the ML model is utilized to stagger the natural frequency,and the PFB is utilized to achieve the weak vibration design.The findings of the present study provide valuable insights into the practical application of weak vibration design.展开更多
基金supported by the National Natural Science Foundation of China (Nos.21876197, 21577166, 21707160)the Chinese Academy of Sciences (Nos.XDB14040301, 29[2015]30, QYZDJ-SSW-DQC017)the K.C.Wong Education Foundation.
文摘Per-and polyfluorinated alkyl substances(PFASs) are commonly used in industrial processes and daily life products.Because they are persistent, they accumulate in the environment, wildlife and humans.Although many studies have focused on two of the most representative PFASs, PFOS and PFOA, the potential toxicity of short-chain PFASs has not yet been given sufficient attention.We used a battery of assays to evaluate the toxicity of several four-carbon and six-carbon perfluorinated sulfonates and carboxyl acids(PFBS,PFHxS, PFBA and PFHxA), with a human mesenchymal stem cell(hMSC) system.Our results demonstrate significant cyto-and potential developmental toxicity for all the compounds analyzed, with shared but also distinct mechanisms of toxicity.Moreover, the effects of PFBS and PFHxS were stronger than those of PFBA and PFHxA, but occurred at higher doses compared to PFOS or PFOA.
基金supported by the National Natural Science Foundation of China(No.22006159)the Natural Science Foundation of Hubei Province,China(No.2021CFA086)the Innovative Team Program of Natural Science Foundation of Hubei Province,China(No.2021CFA032).
文摘To protect the wellbeing of research animals,certain non-invasive measures are in increasing need to facilitate an early diagnosis of health and toxicity.In this study,feces specimen was collected from adult zebrafish to profile the metabolome fingerprint.Variability in fecal metabolite composition was also distinguished as a result of aging,perfluorobutanesulfonate(PFBS)toxicant,and fecal transplantation.The results showed that zebrafish feces was very rich in a diversity of metabolites that belonged to several major classes,including lipid,amino acid,carbohydrate,vitamin,steroid hormone,and neurotransmitter.Fecal metabolites had functional implications to multiple physiological activities,which were characterized by the enrichment of digestion,absorption,endocrine,and neurotransmission processes.The high richness and functional involvement of fecal metabolites pinpointed feces as an abundant source of diagnostic markers.By comparison between young and aged zebrafish,fundamental modifications of fecal metabolomes were caused by aging progression,centering on the neuroactive ligand-receptor interaction pathway.Exposure of aged zebrafish to PFBS pollutant also significantly disrupted the metabolomic structure in feces.Of special concern were the changes in fecal hormone intermediates after PFBS exposure,which was concordant with the in vivo endocrine disrupting effects of PFBS.Furthermore,itwas intriguing that transplantation of young zebrafish feces efficientlymitigated the metabolic perturbation of PFBS in aged recipients,highlighting the health benefits of therapeutic strategies based on gut microbiota manipulation.In summary,the present study provides preliminary clues to evidence the non-invasive advantage of fecal metabolomics in the early diagnosis and prediction of physiology and toxicology.
基金Project supported by the National Natural Science Foundation of China(52300206)the Natural Science Foundation of Jiangsu Province(BK20230705)+2 种基金Industry-University Research Cooperation Project of Jiangsu Province,China(BY20221227)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB610014)the Talent-Recruiting Program of Nanjing Institute of Technology(YKJ202124)。
文摘Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terephthalic acid-modified WO_(3) was prepared and further used as photocatalysts for perfluorobutane sulfonate(PFBS)degradation.In this design,terephthalic acid was used as an electron recombination center and heterojunction mediator,which effectively enhances the migration ability of electron-hole pairs and the physicochemical stability of the catalyst.In addition,in situ synthesis of CeO_(2)onto the WO_(3) surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO_(2)agglomeration.As a result,the CeO_(2)@WO_(3) photocatalyst exhibits excellent PFBS degradation ability(94%for CeO_(2)@WO_(3) vs.19%for CeO_(2)).After the fifth cyclic degradation experiment,the CeO_(2)@WO_(3) photocatalyst still maintains stable degradation efficiency.Furthermore,the reaction mechanism of the PFBS in CeO_(2)@WO_(3) photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry(LC-MS)technique.This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO_(2)@WO_(3) photocatalysts possess a promising prospect for degrading PFBS pollutants.
基金Project supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.12421002)the National Science Funds for Distinguished Young Scholars of China(No.12025204)+1 种基金the National Natural Science Foundation of China(No.12372015)China Scholarship Council(No.202206890065)。
文摘Multi-constrained pipes conveying fluid,such as aircraft hydraulic control pipes,are susceptible to resonance fatigue in harsh vibration environments,which may lead to system failure and even catastrophic accidents.In this study,a machine learning(ML)-assisted weak vibration design method under harsh environmental excitations is proposed.The dynamic model of a typical pipe is developed using the absolute nodal coordinate formulation(ANCF)to determine its vibrational characteristics.With the harsh vibration environments as the preserved frequency band(PFB),the safety design is defined by comparing the natural frequency with the PFB.By analyzing the safety design of pipes with different constraint parameters,the dataset of the absolute safety length and the absolute resonance length of the pipe is obtained.This dataset is then utilized to develop genetic programming(GP)algorithm-based ML models capable of producing explicit mathematical expressions of the pipe's absolute safety length and absolute resonance length with the location,stiffness,and total number of retaining clips as design variables.The proposed ML models effectively bridge the dataset with the prediction results.Thus,the ML model is utilized to stagger the natural frequency,and the PFB is utilized to achieve the weak vibration design.The findings of the present study provide valuable insights into the practical application of weak vibration design.
