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A simple fluorescence anisotropy assay for detection of bisphenol A using fluorescently labeled aptamer

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Journal of Environmental Sciences 2020年第11期32卷 19-24页

作者： Liying Liu qiang zhao State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental analysis.Taking advantage of aptamers as affinity ligands and fluorescence anisotropy(FA)analysis,we developed a simple and rapid FA assay for BPA by employing a single tetramethylrhodamine(TMR)labeled short 35-mer DNA aptamer against BPA.The assay is based on the BPA-binding induced conformation change of TMR-labeled aptamer and alteration of interaction between TMR and guanine bases,resulting in change of FA signals.We screened the FA change of aptamer probes having TMR label on a specific site of the aptamer upon BPA addition.The aptamer with a TMR label on the 22nd T base showed large FA-decreasing response to BPA and maintained good binding affinity to BPA.By using this TMR-labeled aptamer,we achieved FA detection of BPA with a detection limit of 0.5μmol/L under the optimized conditions.This assay was selective towards BPA and enabled the detection of BPA spiked in tap water sample,showing the potential applications on water samples.

关键词： Bisphenol A Aptamer Fluorescence anisotropy Fluorescence polarization Microscale thermophoresis Binding affinity

Isothermal oxidation behavior of Nb-bearing austenitic cast steels at 950℃

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International Journal of Minerals,Metallurgy and Materials 2022年第4期29卷 814-824页

作者： Hailong zhao Longfei Li qiang Feng Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China

The oxidation behaviors of three austenitic cast steels with different morphologies of primary carbides at 950℃ in air were investigated using scanning electron microscopy,energy dispersive spectroscopy,and focused ion beam/transmission electron microscopy.Their oxidation kinetics followed a logarithmic law,and the oxidation rate can be significantly decreased as long as a continuous silica layer formed at the scale/substrate interface.When the local Si concentration was inadequate,internal oxidation occurred beneath the oxide scale.The spallation of oxides during cooling can be inhibited with the formation of internal oxidation,owing to the reduced mismatch stress between the oxide scale and the substrate.The“Chinese-script”primary Nb(C,N)was superior to the dispersed primary Nb(C,N)in suppressing the oxidation penetration in the interdendritic region by supplying a high density of quick-diffusion Cr channels.In addition,the innermost and outermost oxidation layers were enriched with Cr,whereas the Cr evaporation in the outermost layer was significant when the water vapor concentration in the environment was high enough.These findings further the understanding regarding the oxidation behavior of austenitic cast steels and will promote the alloy development for exhaust components.

关键词： austenitic cast steels isothermal oxidation primary Nb(C,N) internal oxidation Cr depletion

Passage shock wave/boundary layer interaction control for transonic compressors using bumps

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Chinese Journal of Aeronautics 2022年第2期35卷 82-97页

作者： Yongzhen LIU Wei zhao Qingjun zhao qiang ZHOU Jianzhong XU Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Light-duty Gas Turbine Chinese Academy of SciencesBeijing 100190China

Flow separation due to shock wave/boundary layer interaction is dominated in blade passage with supersonic relative incoming flow,which always accompanies aerodynamic performance penalties.A loss reduction method for smearing the passage shock foot via Shock Control Bump(SCB)located on transonic compressor rotor blade suction side is implemented to shrink the region of boundary layer separation.The curved windward section of SCB with constant adverse pressure gradient is constructed ahead of passage shock-impingement point at design rotor speed of Rotor 37 to get the improved model.Numerical investigations on both two models have been conducted employing Reynolds-Averaged Navier-Stokes(RANS)method to reveal flow physics of SCB.Comparisons and analyses on simulation results have also been carried out,showing that passage shock foot of baseline is replaced with a family of compression waves and a weaker shock foot for moderate adverse pressure gradient as well as suppression of boundary layer separations and secondary flow of low-momentum fluid within boundary layer.It is found that adiabatic efficiency and total pressure ratio of improved blade exceeds those of baseline at 95%-100%design rotor speed,and then slightly worsens with decrease of rotatory speed till both equal below 60%rated speed.The investigated conclusion implies a potential promise for future practical applications of SCB in both transonic and supersonic compressors.

关键词： Flow separation Passage shock Shock Control Bump(SCB) Shock wave/boundary layer interaction Transonic compressors

Wind speed prediction based on nested shared weight long short-term memory network

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The Journal of China Universities of Posts and Telecommunications 2021年第1期28卷 41-51页

作者： Han Fengquan Han Yinghua Lu Jing ZHAO Qiang School of Computer and Communication Engineering Qinhuangdao Branch of Northeast UniversityQinhuangdao 066000China

With the expansion of wind speed data sets, decreasing model training time is of great significance to the time cost of wind speed prediction. And imperfection of the model evaluation system also affect the wind speed prediction. To address these challenges, a hybrid method based on feature extraction, nested shared weight long short-term memory(NSWLSTM) network and Gaussian process regression(GPR) was proposed. The feature extraction of wind speed promises the best performance of the model. NSWLSTM model reduces the training time of long short-term memory(LSTM) network and improves the prediction accuracy. Besides, it adopted a method combined NSWLSTM with GPR(NSWLSTM-GPR) to provide the probabilistic prediction of wind speed. The probabilistic prediction can provide information that deviates from the predicted value, which is conducive to risk assessment and optimal scheduling. The simulation results show that the proposed method can obtain high-precision point prediction, appropriate prediction interval and reliable probabilistic prediction results with shorter training time on the wind speed prediction.

关键词： wind speed prediction feature extraction long short-term memory(LSTM)network shared weight forecast uncertainty

Which sectors should be covered by the EU Carbon Border Adjustment Mechanism?

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Advances in Climate Change Research 2023年第6期14卷 952-962页

作者： Bo-qiang LIN Heng-Song zhao School of Management China Institute for Studies in Energy PolicyXiamen UniversityXiamen 361005China

The European Union(EU)is developing the Carbon Border Adjustment Mechanism(CBAM)to address carbon leakage in international trade.However,the EU has paid inadequate attention to input-output linkages,specifically those in the steel,aluminum,and fertiliser industries.This study aims to identify priority sectors eligible for initial regulation within the emissions-intensive trade-exposed(EITE)industries based on input-output linkages and compare its impacts with the current CBAM sector coverage.This study constructs a Global Production Network(GPN)and Carbon Flow Network(CFN)to present the input trade and embodied carbon flows for the EITE industries.This study highlights the role of the EITE industries as influential nodes in the production network and how the EITE industries in the EU contribute to carbon emissions.To improve the economy and political acceptability,CABM should cover four priority sectors with low economic impacts but a crucial role in reducing emissions,such as plastics,phosphorus fertiliser,aluminum,and copper industry.

关键词： Carbon Border Adjustment mechanism Input-output analysis Hypothetical extraction method Production network Embodied carbon emissions

Cenozoic Tethyan changes dominated Eurasian animal evolution and diversity patterns

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Zoological Research 2022年第1期43卷 3-13页

作者： Zhe zhao Zhong-E Hou Shu-qiang Li Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China

Cenozoic tectonic evolution in the Tethyan region has greatly changed the landforms and environment of Eurasia,driving the evolution of animals and greatly affecting the diversity patterns of Eurasian animals.By combining the latest Tethyan paleogeographic models and some recently published Eurasian zoological studies,we systematically summarize how tectonic evolution in the Tethyan region has influenced the evolution and diversity patterns of Eurasian animals.The convergence of continental plates,closure of Tethys Sea,and Tethyan sea-level changes have directly affected the composition and spatial distribution of Eurasian animal diversity.The topographic and environmental changes caused by Tethyan tectonics have determined regional animal diversity in Eurasia by influencing animal origin,dispersal,preservation,diversification,and extinction.The ecological transformations resulted in the emergence of new habitats and niches,which promoted animal adaptive evolution,specialization,speciation,and expansion.We highlight that the Cenozoic tectonic evolution of the Tethyan region has been responsible for much of the alteration in Eurasian animal distribution and has been an essential force in shaping organic evolution.Furthermore,we generalize a general pattern that Tethyan geological events are linked with Eurasian animal evolution and diversity dynamics.

关键词： Tethys Mediterranean Biogeography Zoogeography Phylogeny

Prevalence of Brick Tea-type Fluorosis in Children Aged 8–12 Years in Qinghai Province,China

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Biomedical and Environmental Sciences 2021年第4期34卷 334-336页

作者： LI qiang zhao Zhi Jun Qinghai Institute for Endemic Disease Prevention and Control Xining 811602QinghaiChina

Fluorosis is a serious health problem,and an endemic disease in certain areas in China,India,and some countries in Africa[1].There are three types of fluorosis which includes drinking-water type fluorosis,coal-burning pollution type fluorosis,and brick tea-type fluorosis.Coal-burning pollution type fluorosis and brick tea-type fluorosis are found only in China's Mainland mainland.

关键词： mainland pollution Fluorosis

Response to the outbreak of severe acute hepatitis of unknown origin in children

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World Journal of Pediatrics 2022年第8期18卷 525-528页

作者： Jie Chen qiang Shu Zheng‑Yan zhao National Clinical Research Center for Child Health National Children’s Regional Medical CenterChildren’s HospitalZhejiang University School of MedicineHangzhou 310052China

During October 2021 and February 2022,nine pediatric patients with acute hepatitis of unknown origin were identifed in Children’s of Alabama[1].These patients were tested negative for hepatitis viruses;and several other etiologies of hepatitis in children including autoimmune hepatitis were ruled out[1].In a short period of time,the number of cases has surged in many countries;importantly,the rate has exceeded past annual incidence in various regions[2–4].On 23 April 2022,World Health Organization(WHO)has issued a warning on severe hepatitis of unknown origin in children[5].As of May 18,575 suspected cases have been identifed in Europe,United States of American(USA),Israel,India,Japan,and other countries;35 children required liver transplantation and 11 died[6].

关键词： hepatitis acute origin

Rapid sensitive fluorescence detection of cadmium(Ⅱ)with pyrene excimer switching aptasensor

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Journal of Environmental Sciences 2023年第11期133卷 1-7页

作者： Hao Yu qiang zhao State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China School of Environment Hangzhou Institute for Advanced StudyUCASHangzhou 310000China

Heavy metal cadmium(Ⅱ)contamination often occurs,causing great health risk to human due to high toxicity of cadmium(Ⅱ).Rapid,sensitive and simple detection of cadmium(Ⅱ)are of great importance in environmental monitoring.Taking advantage of aptamer in specific recognition,easy modification,and capability of binding-induced structure change,here we reported a simple fluorescent sensor with rapid and sensitive response for Cd^(2+)using aptamer pyrene excimer switch.The aptamer was labeled with dual pyrene molecules at two ends of the sequence.The binding of Cd^(2+)to this aptamer probe brought the pyrene labels into close proximity and enhanced formation of a pyrene excimer,which generated increased fluorescence at 485 nm.By measuring the fluorescence of pyrene excimer,we achieved detection of Cd^(2+)with this aptasensor.Under the optimum experimental conditions,the detection limit of Cd^(2+)reached nanomolar levels.This method was selective and allowed for the detection of Cd^(2+)in tap water.This fluorescence aptasensor is promising for rapid detection of Cd^(2+)in broad applications.

关键词： Aptamer Cadmium Pyrene excimer Fluorescence Sensor