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Stabilization/solidification mechanisms of tin tailings and fuming slag-based geopolymers for different heavy metals

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Frontiers of environmental Science & engineering 2024年第5期18卷 43-55页

作者： xian Zhou Zhengfu zhang Hui Yang School of Materials Science and engineering Kunming University of Science and TechnologyKunming650093China Kunming Metallurgical Research Institute Co. Ltd.Kunming650031China

Tin mine tailings(TMT)and fuming slag(FS)contain many heavy metals(As,Cr,Cu,Zn and Mn)that cause severe pollution to the environment.Herein,geopolymers were prepared using TMT,FS and flue gas desulfurization gypsum(FGDG)to immobilize heavy metals,and their compressive strength and heavy metal leaching toxicity were investigated.It was first determined that T4F5(TMT:FS=4:5)sample exhibited the highest compressive strength(7.83 MPa).T4F5 achieved 95%immobilization efficiency for As and Cr,and nearly 100%for Cu,Zn and Mn,showing good immobilization performance.A series of characterization analyses showed that heavy metal cations can balance the charge in the geopolymer and replace Al in the geopolymer structure to form covalent bonds.In addition,about 2%–20%of heavy metal Fe was immobilized in hydration products,heavy metal hydroxides and non-bridging Si–O and Al–O coordination with silica-aluminate matrices.AsO33−was oxidized into AsO43−,which may form Ca–As or Fe–As precipitates.Cr2O72−was converted to CrO42−under alkaline environment and then combined with OH−to form Cr(OH)3 precipitates.Mn2+may react directly with dissolved silicate to form Mn2SiO4 and also form Mn(OH)2 precipitates.The unstable Mn(OH)2 can be further oxidized to MnO2.The heavy metal cations were immobilized in the silicoaluminate lattice,while the anions tended to form insoluble precipitates.These results may benefit the industry and government for better handling of TMT,FS and solid wastes containing the abovementioned five heavy metals.

关键词： Heavy metals Cementitious materials Tin tailings Stabilization/solidification Redox

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Probing cell membrane integrity using a histone-targeting protein nanocage displaying precisely positioned fluorophores

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Nano Research 2023年第1期16卷 894-904页

作者： Ti Fang Chaoqun Li Ao Liang Hui zhang Fan zhang xian-en zhang Yi-Yu Yang Feng Li Guangzhou Women and Children’s Medical Center Guangzhou Medical UniversityGuangzhou 510120China State Key Laboratory of Virology Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan 430071China Faculty of Synthetic Biology Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Cell membrane integrity is fundamental to the normal activities of cells and is involved in both acute and chronic pathologies.Here,we report a probe for analyzing cell membrane integrity developed from a 9 nm-sized protein nanocage named Dps via fluorophore conjugation with high spatial precision to avoid self-quenching.The probe cannot enter normal live cells but can accumulate in dead or live cells with damaged membranes,which,interestingly,leads to weak cytoplasmic and strong nuclear staining.This differential staining is found attributed to the high affinity of Dps for histones rather than DNA,providing a staining mechanism different from those of known membrane exclusion probes(MEPs).Moreover,the Dps nanoprobe is larger in size and thus applies a more stringent criterion for identifying severe membrane damage than currently available MEPs.This study shows the potential of Dps as a new bioimaging platform for biological and medical analyses.

关键词： protein engineering fluorescent probes nanoparticles cell membrane damage ferritin superfamily

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A microfluidic cell chip for virus isolation via rapid screening for permissive cells

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Virologica Sinica 2022年第4期37卷 547-557页

作者： Weide Su Jingjiang Qiu Ying Mei xian-en zhang Yong He Feng Li State Key Laboratory of Virology Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan430071China School of Mechanics and Safety engineering Zhengzhou UniversityZhengzhou450001China Faculty of Synthetic Biology Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055China National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing100101China State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou310027China University of Chinese Academy of Sciences Beijing100049China Current address:Wuhan Institute of Biological Products Co. Ltd.Wuhan430070China

Virus identification is a prerequisite not only for the early diagnosis of viral infectious diseases but also for the effective prevention of epidemics.Successful cultivation is the gold standard for identifying a virus,according to the Koch postulates.However,this requires screening for a permissive cell line,which is traditionally time-,reagent-and labor-intensive.Here,a simple and easy-to-operate microfluidic chip,formed by seeding a variety of cell lines and culturing them in parallel,is reported for use in virus cultivation and virus-permissive host-cell screening.The chip was tested by infection with two known viruses,enterovirus 71(EV71)and influenza virus H1N1.Infection with EV71 and H1N1 caused significant cytopathic effects(CPE)in RD and MDCK cells,respectively,demonstrating that virus cultivation based on this microfluidic cell chip can be used as a substitute for the traditional plate-based culture method and reproduce the typical CPE caused by virus infection.Using this microfluidic cell chip method for virus cultivation could make it possible to identify an emerging virus in a highthroughput,automatic,and unprecedentedly fast way.

关键词： Virus cultivation Microfluidic cell chip Permissive cell enterovirus 71(EV71) Influenza virus

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Limit Theorems for Critical Galton-Watson Processes with Immigration Stopped at Zero

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Acta Mathematica Sinica,english Series 2024年第2期40卷 435-450页

作者： Dou Dou LI Mei zhang xian Yu zhang College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124P.R.China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero W.Some precise estimation on the probability generating function of the n-th population are obtained,and the tail probability of the life period of W is studied.Based on above results,two conditional limit theorems for W are established.

关键词： Branching immigration critical life period limit theorems

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Curcumin Interferes with TGF-β1-Induced Fibrosis in NRK-49F Cells by Reversing ADAMTS18 Gene Methylation

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Chinese Journal of Integrative Medicine 2024年第7期30卷 600-607页

作者： XU Ben zhang Jia-en YE Lin YUAN Chang-wei Department of Urology Peking University First Hospital and Institute of Urology Peking UniversityNational Urological Cancer Center

Objective: To explore the molecular mechanism by which curcumin affects renal interstitial fibrosis（RIF） progression by regulating ADAM metallopeptidase with thrombospondin type 1 motif 18（ADAMTS18） methylation. Methods: NRK-49F cells RIF model were induced with transforming growth factor β1（TGF-β1）. Effects of different concentrations of curcumin（0, 10, 20, and 30 μmol/L） on cell proliferation, cell cycle, cell apoptosis as well as cyclin D1 expression were analyzed by cell counting kit-8, flow cytometry and Western blot, respectively. ADAMTS18 methylation levels were determined by methylation-specific polymerase chain reaction. ADAMTS18, fibronectin（FN）, type Ⅰ collagen（Col-Ⅰ） and alpha-smooth muscle actin（α-SMA） mRNA and protein expressions were analyzed by real-time PCR（RT-PCR） and Western blot, respectively. Meanwhile, cells were treated with 50 mmol/L 5-aza-2'-deoxycytidine（5-aza-dC, demethylation agent） for 72 h. Effect of curcumin on extracellular matrix（ECM） deposition was evaluated by immunochemical staining and Western blot. NRK-49F cells were transfected with ADAMTS18 small interfering RNA and grouped into a normal control, ADAMTS18-knock-out（KO）, and ADAMTS18-KO+ 30 μmol/L curcumin groups, and whether curcumin can reverse the effect of ADAMTS18 knockdown on RIF was evaluated. Results: Compared with the control group, TGF-β1 significantly inhibited the proliferation of NRK-49F cells, blocked the G1/G0phase, promoted cell apoptosis and inhibited cyclin D1 expression（Pent concentrations of curcumin, 30 μmol/L curcumin significantly reversed these processes（P<0.01）. Immunochemical staining and Western blot results showed that curcumin significantly inhibited the deposition of FN, Col-Ⅰ and α-SMA（P<0.01）. Curcumin and 5-zaz-dC had synergistic effects, promoting ADAMTS18 expression, removing ADAMTS18 methylation, and reducing ECM deposition. ADAMTS18 knockdown promoted ECM accumulation, and curcumin reversed this process（P<0.01）. Conclusion: TGF-β1 induced fibrosis in NRK-49F cells.

关键词： renal fibrosis curcumin Chinese medicine ADAMTS18 methylation modification

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A switch-on molecular biosensor for detection of caspase-3 and imaging of apoptosis of cells

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Science China(Life Sciences) 2022年第3期65卷 540-549页

作者： Rui Gong Dianbing Wang Ghulam Abbas Shimin Li Qian Liu Mengmeng Cui xian-en zhang National Laboratory of Biomacromolecules CAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Faculty of Synthetic Biology Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Apoptosis is a form of programmed cell death that is essential for maintaining internal environmental stability.Disordered apoptosis can cause a variety of diseases;therefore,sensing apoptosis can provide help in study of mechanism of the relevant diseases and drug development.It is known that caspase-3 is a key enzyme involved in apoptosis and the expression of its activity is an indication of apoptosis.Here,we present a genetically encoded switch-on m Neon Green2-based molecular biosensor.m Neon Green2 is the brightest monomeric green fluorescent protein.The substrate of caspase-3,DEVD amino acid residues,is inserted in it,while cyclized by insertion of Nostoc punctiforme Dna E intein to abolish the fluorescence(inactive state).Caspase-3-catalyzed cleavage of DEVD linearizes m Neon Green2 and rebuilds the natural barrel structure to restore the fluorescence(activated state).The characterization exhibited that the Caspase-3 biosensor has shortened response time,higher sensitivity,and prolonged functional shelf life in detection of caspase-3 amongst the existing counterparts.We also used the Caspase-3 biosensor to evaluate the effect of several drugs on the induction of apoptosis of He La and MCF-7 tumor cells and inhibition of Zika virus invasion.

关键词： apoptosis caspase-3 molecular biosensor molecular imaging Zika virus

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Hybrid vibration isolation optimization of a flexible manipulator based on neural network agent model

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Chinese Journal of Aeronautics 2024年第5期37卷 482-505页

作者： Yongxin zhang Liang LI Dingguo zhang Wei-Hsin LIAO xian GUO School of Science Nanjing University of Science and TechnologyNanjing 210094China Department of Mechanical and Automation engineering The Chinese University of Hong KongHong KongChina

Segmented Active Constrained Layer Damping(SACLD)is an intelligent vibration-damping structure,which could be applied to the sectors of aviation,aerospace,and transportation engineering to reduce the vibration of flexible structures.Moreover,machine learning technology is widely used in the engineering field because of its efficient multi-objective optimization.The dynamic simulation of a rotational segmental flexible manipulator system is presented,in which enhanced active constrained layer damping is carried out,and the neural network model of Genetic Algorithm-Back Propagation(GA-BP)algorithm is investigated.Vibration suppression and structural optimization of the SACLD manipulator model are studied based on vibration mode and damping prediction.The modal responses of the SACLD manipulator model at rest and rotation are obtained.In addition,the four model indices are optimized using the GA-BP neural network:axial incision size,axial incision position,circumferential incision size,and circumferential incision position.Finally,the best model for vibration suppression is obtained.

关键词： Machine learning Vibration suppression Flexible manipulator Segmented active constrained layer damping Structural optimization

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Communication Resource-Efficient Vehicle Platooning Control With Various Spacing Policies

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 362-376页

作者： Xiaohua Ge Qing-Long Han xian-Ming zhang Derui Ding IEEE School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.

关键词： Automated vehicles constant time headway spacing constant spacing cooperative adaptive cruise control event-triggered communication vehicle platooning

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Altered hACE2 binding affinity and S1/S2 cleavage efficiency of SARS-CoV-2 spike protein mutants affect viral cell entry

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Virologica Sinica 2023年第4期38卷 595-605页

作者： Ke Wang Yu Pan Dianbing Wang Ye Yuan Min Li Yuanyuan Chen Lijun Bi xian-en zhang National Key Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing100101China Faculty of Synthetic Biology Shenzhen Institute of Advanced TechnologyShenzhen518055China University of Chinese Academy of Sciences Beijing100101China

SARS-CoV-2 variants are constantly emerging,hampering public health measures in controlling the number of infections.While it is well established that mutations in spike proteins observed for the different variants directly affect virus entry into host cells,there remains a need for further expansion of systematic and multifaceted comparisons.Here,we comprehensively studied the effect of spike protein mutations on spike expression and proteolytic activation,binding affinity,viral entry efficiency and host cell tropism of eight variants of concern(VOC)and variants of interest(VOI).We found that both the full-length spike and its receptor-binding domain(RBD)of Omicron bind to hACE2 with an affinity similar to that of the wild-type.In addition,Alpha,Beta,Delta and Lambda pseudoviruses gained significantly enhanced cell entry ability compared to the wild-type,while the Omicron pseudoviruses showed a slightly increased cell entry,suggesting the vastly increased rate of transmission observed for Omicron variant is not associated with its affinity to hACE2.We also found that the spikes of Omicron and Mu showed lower S1/S2 cleavage efficiency and inefficiently utilized TMPRSS2 to enter host cells than others,suggesting that they prefer the endocytosis pathway to enter host cells.Furthermore,all variants'pseudoviruses we tested gained the ability to enter the animal ACE2-expressing cells.Especially the infection potential of rats and mice showed significantly increased,strongly suggesting that rodents possibly become a reservoir for viral evolution.The insights gained from this study provide valuable guidance for a targeted approach to epidemic control,and contribute to a better understanding of SARS-CoV-2 evolution.

关键词： SARS-CoV-2 Variants of Concern(VOC) Omicron Binding affinity Viral entry Host-tropism

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Coordination environments build up and tune a superior synergistic “genome” toward novel trifunctional (TM-N_(x)O_(4−x))@g- C_(16)N_(3)-H_(3): High-throughput inspection of ultra-high activity for water splitting and oxygen reduction reactions

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Nano Research 2024年第4期17卷 2337-2351页

作者： Chunyao Fang xian Wang Qiang zhang Xihang zhang Chenglong Shi Jingcheng Xu Mengyu Yang Department of Physics University of Shanghai for Science and TechnologyShanghai 200093China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

Emerging as a prominent area of focus in energy conversion and storage technologies,the development of highly active metal-based single-atom catalysts(SACs)holds great signiﬁcance in searching alternatives to replace precious metals toward the efficient,stable,and low-cost hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).Combining the tremendous tunability of ligand and coordination environment with rich metal-based electrocatalysts can create breakthrough opportunities for achieving both high stability and activity.Herein,we propose a novel and stable holey graphene-like carbon nitride monolayer g-C_(16)N5(N_(4)@g-C_(16)N_(3))stoichiometries interestingly behaving as a natural substrate for constructing SACs((TM-N_(4))@g-C_(16)N_(3)),whose evenly distributed holes map rich and uniform nitrogen coordination positions with electron-rich lone pairs for anchoring transition metal(TM)atoms.Then,we employed density functional theory(DFT)calculations to systematically investigate the electrocatalytic activity of(TM-N_(4))@g-C_(16)N_(3) toward HER/OER/ORR,meanwhile considering the synergistic modulation of H-loading and O-coordination((TM-N_(x)O_(4-x))@g-C_(16)N_(3)^(-)H_(3),x=0–4).Together a“four-step procedure”screening mechanism with the first-principles high-throughput calculations,we find that(Rh-N_(4))and(Ir-N_(2)O_(2)-II)distributed on g-C_(16)N_(3)^(-)H_(3) can modulate the adsorption strength of the adsorbates,thus achieving the best HER/OER/ORR performance among 216 candidates,and the lowest overpotential of 0.098/0.3/0.46 V and 0.06/0.48/0.45 V,respectively.Additionally,the d-band center,crystal orbital Hamilton population(COHP),and molecular orbitals are used to reveal the OER/ORR activity source.Particularly,the Rh/Ir-d orbital is dramatically hybridized with the O-p orbital of the oxygenated adsorbates,so that the lone-electrons incipiently locate at the antibonding orbital pair up and populate the downward bonding orbital,allowing oxygena

关键词： single atom catalysts loading and coordination hydrogen evolution reaction oxygen evolution reaction oxygen reduction reaction

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