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Aggregation and stability of selenium nanoparticles: Complex roles of surface coating, electrolytes and natural organic matter

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Journal of Environmental Sciences 2023年第8期130卷 14-23页

作者： Sujuan Yu Hao liu Rui Yang Wenjing Zhou Jingfu liu 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 Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department of Environmental Science&EngineeringNorth China Electric Power UniversityBaoding 071000China

the application of selenium nanoparticles(SeNPs)as nanofertilizers may lead to the release of SeNPs into aquatic ***,the environmental behavior of SeNPs is rarely *** this study,using alginate-coated SeNPs(Alg-SeNPs)and polyvinyl alcohol-coated SeNPs(PVA-SeNPs)as models,we systematically investigated the aggregation and stability of SeNPs under various water ***-SeNPs were highly stable in mono-and polyvalent electrolytes,probably due to the strong steric hindrance of the capping ***-SeNPs only suffered from a limited increase in size,even at 2500 mmol/L NaCl and 200 mmol/L MgCl_(2),while they underwent apparent aggregation in CaCl_(2) and LaCl_(3) *** binding of Ca^(2+) and La^(3+) with the guluronic acid part in alginate induced the formation of cross-linking *** organic matter enhanced the stability of Alg-SeNPs in monovalent electrolytes,while accelerated the attachment of Alg-SeNPs in polyvalent electrolytes,due to the cation bridge *** long-term stability of SeNPs in natural water showed that the aggregation sizes of Alg-SeNPs and PVA-SeNPs increased to several hundreds of nanometers or above 10μm after 30 days,implying that SeNPs may be suspended in the water column or further settle down,depending on the surrounding water *** study may contribute to the deep insight into the fate and mobility of SeNPs in the aquatic *** varying fate of SeNPs in different natural waters also suggests that the risks of SeNPs to organisms living in diverse depths in the aquatic compartment should be concerned.

关键词： Selenium nanoparticles Aggregation Stability Surface coating Electrolytes Natural organic matter

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Aedes Surveillance and Risk Warnings for Dengue—China,2016−2019

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China CDC weekly 2020年第24期2卷 431-437页

作者： Xiaobo liu Qiyong liu State Key Laboratory of Infectious Disease Prevention and Control Collaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesWHO Collaborating Centre for Vector Surveillance and ManagementNational Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina

Introduction:Aedes surveillance plays an important role in the risk warning and control of dengue in *** study analyzed Aedes larval density and its indicated dengue risk in 23 provincial-level administrative divisions(PLADs)from 2016 to 2019 to provide scientific evidence for sustainable dengue management(SDM)in the ***:the Breteau index(BI)and Mosq-ovitrap index(MOI)methods were utilized for Aedes larvae surveillance in 23 PLADs with 3 categories based on dengue risk stratification and Aedes *** and MOI were calculated and then dengue risk warning was carried out for the guidance of SDM in these PLADs based on the findings of Aedes ***:the seasonal fluctuations of Aedes larval density were similar in six class I PLADs during 2016–2019,and the density of Aedes larvae was relatively high in the PLADs of Zhejiang,Hainan,and Fujian while it was relatively low in Yunnan and *** Shanghai and Jiangsu,the BI of all other class II PLADs had reached the dengue transmission threshold during the study *** class III PLADs,the BI had reached dengue transmission threshold in most months in Shandong and Hebei during the study *** MOI was higher than 5 from June to September in all the studied years in Guangdong and was higher in most studied years in *** MOI of Beijing in August reached dengue transmission or outbreak threshold from 2017 to *** and Implications for Public Health Practice:Most class I and class II PLADs were at risk of dengue transmission during the surveillance months,2016–*** Aedes surveillance and risk warnings should be carried out in specific PLADs so as to provide scientific basis for SDM in the future.

关键词： Aedes utilized surveillance

A Novel Dual Pointer Approach for Entity Mention Extraction

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Chinese Journal of Electronics 2021年第1期30卷 127-133页

作者： liu Jie PANG Yihe ZHANG Kai liu Lizhen YU Zhengtao Department of Information Engineering Capital Normal University Research Center for Language Intelligence Capital Normal University Department of Information Engineering and Automation Kunming University of Science and Technology

the named entity extraction task aims to extract entity mentions from the unstructured text,including names of people, places, institutions and so on. It plays an important role in many Natural language processing(NLP) tasks, such as knowledge bases construction, automatic question answering system and information extraction. Most of the existing entity extraction studies are based on the long text data, which are easier to annotate due to the sufficient contextual information. Extracting entities from short texts such as search queries, conversations is still a challenging *** paper proposes a dual pointer approach for entity mention extraction, it extracts one entities by two position pointers of the input sentence. the end-to-end deep neural networks model based on the proposed approach can extract the entities by serially generating the dual *** evaluation results on the Chinese public dataset show that the model achieves the state-of-the-art results over the baseline models.

关键词： entity mention extraction novel dual pointer approach Chinese public dataset text analysis deep learning (artificial intelligence) long text data end-to-end deep neural networks model natural language processing automatic question answering system named entity extraction task unstructured text question answering (information retrieval) natural language processing tasks query processing knowledge bases construction knowledge based systems information extraction

Layer-dependent signatures for exciton dynamics in monolayer and multilayer WSe2 revealed by fluorescence lifetime imaging measurement

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Nano Research 2020年第3期13卷 661-666页

作者： Yuanshuang liu Huanglong Li Cuicui Qiu Xiangmin Hu Dameng liu State Key Laboratory of tribology Tsinghua UniversityBeijing 100084China Beijing Innovation Center for Future Chip Tsinghua UniversityBeijing 100084China

two-dimensional(2D)transition-metal dichalcogenide(tMD)materials have aroused noticeable interest due to their distinguished electronic and optical ***,little is known about their complex exciton properties together with the exciton dynamics process which have been expected to influence the performance of optoelectronic *** process of fluorescence can well reveal the process of exciton transition after *** this work,the room-temperature layer-dependent exciton dynamics properties in layered WSe2 are investigated by the fluorescence lifetime imaging microscopy(FLIM)for the first *** paper focuses on two mainly kinds of excitons including the direct transition neutral excitons and *** with the lifetime of neutral excitons(thin four-layer),trions possess a longer lifetime(~6.6 ns within four-layer)which increases with the number of *** attribute the longer-lived lifetime to the increasing number of trions as well as the varieties of trion configurations in thicker ***,the whole average lifetime increases over 10%when WSe2 flakes added up from monolayer to *** paper provides a novel tuneable layer-dependent method to control the exciton dynamics process and finds a relatively longer transition lifetime of trions at room temperature,enabling to investigate in the charge transport in tMD-based optoelectronics devices in the future.

关键词： two-dimensional(2D)WSe2 exciton dynamics fluorescence lifetime fluorescence lifetime imaging microscopy(FLIM) density functional theory(DFt)

Almost Disturbance Decoupling for HOFA Nonlinear Systems with Strict-Feedback Form

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Journal of Systems Science & Complexity 2022年第2期35卷 481-501页

作者： WANG Na liu Xiaoping liu Cungen WANG Huanqing ZHOU Yucheng School of Information and Electrical Engineering Shandong Jianzhu UniversityJinan 250101China Faculty of Engineering Lakehead UniversityThunder BayON P7B 5E1Canada the Department of Mathematics Bohai UniversityJinzhou 121013China

the article is devoted to the almost disturbance decoupling problem for high-order fully actuated(HOFA)nonlinear systems with strict-feedback *** the full-actuation feature of high-order fully actuated systems and Lyapunov stability theory,a state feedback control law and virtual control laws are *** unknown disturbances are handled by almost disturbance decoupling(ADD)***,the effectiveness of the control strategy is verified by stability analysis and simulation.

关键词： Almost disturbance decoupling high-order fully actuated systems strict-feedback systems

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Step-Directed Deposition of Au Nanostructures By Electron Beam Evaporation

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Journal of Rare Earths 2004年第Z2期22卷 141-144页

作者： Xu Xiangdong liu Zhihong Wang Yinchuan liu Zhongfan Institute of Microelectronics Tsinghua UniversityBeijing 100084China Institute of MicroelectronicsTsinghua UniversityBeijing 100084China Center for Nanoscale Science & TechnologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Center for Nanoscale Science & TechnologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Au atoms were vaporized by electron beam evaporation, and their subsequent growths on Si (111 ) and highly ordered pyrolytic graphite (HOPG) substrates were studied using atomic force microscopy. Results show that Au nanoparticles tend to nucleate and grow regularly along the step edges of HOPG, however, nanoparticles are distributed homogeneously over the whole Si substrate. the possibility of controlled growth of Au in ultrahigh vacuum with peculiar surface structures was preseuted.

关键词： electron beam evaporation HOPG Au controlled growth ultrahigh vacuum

Hydrogel-based artificial enzyme for combating bacteria and accelerating wound healing

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Nano Research 2020年第2期13卷 496-502页

作者： Hao Qiu Fang Pu Zhengwei liu Xuemeng liu Kai Dong Chaoqun liu Jinsong Ren Xiaogang Qu State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied ChemistryChinese Acadermy of SciencesChangchun 130022China University of Science and technology of China Hefei 230026China University of Chinese Academy of Sciences Beijing 100039China

Artificial enzymes have provided great antimicrobial activity to combat wound ***,the lack of tissue repair capability compromised their treatment ***,development of novel artificial enzyme concurrently with the excellent antibacterial activity and the property of promoting wound healing are ***,we demonstrated the hydrogel-based artificial enzyme composed of copper and amino acids possessed intrinsic peroxidase-like catalytic activity,which could combat wound pathogen effectively and accelerate wound healing by stimulating angiogenesis and collagen ***,the system possesses good biocompatibility for practical *** synergic effect of the hydrogel-based artificial enzyme promises the system as a new paradigm in bacteria-infected wound healing therapy.

关键词： hydrogel-based artificial enzyme peroxidase-like activity wound healing anti-bacteria

Porous polybenzimidazole membranes with positive charges enable an excellent anti-fouling ability for vanadium-methylene blue flow battery

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Journal of Energy Chemistry 2022年第5期31卷 247-254页

作者： Dongju Chen Guangyu liu Jie liu Changkun Zhang Zhizhang Yuan School of Chemistry and Chemical Engineering Liaoning Normal UniversityHuanghe Road 850Dalian 116029LiaoningChina Division of Energy Storage Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of Sciences457 Zhongshan RoadDalian 116023LiaoningChina

A cost-effective, high-performance and highly stable membrane has always been in intensively needed in aqueous organic-based flow batteries. Here we present a porous polybenzimidazole(PBI) membrane with positive charges that endow the membrane with a high rejection and an excellent anti-fouling ability for target organic molecule and asymmetric structure that affords a high conductivity for vanadiummethylene blue flow battery(V-MB FB). the morphologies and thickness of separating layer in particular of the porous PBI can be well adjusted by simply altering the polymer concentration in the cast solution and further afford the membrane with a controllable property in terms of both ion selectivity and ion conductivity. As a result, a V-MB FB assembled with a porous PBI membrane delivers a coulombic efficiency(CE) of 99.45% and an energy efficiency(EE) of 86.10% at a current density of 40 mA cm^(-2), which is 12% higher than that afforded by a Nafion 212 membrane. Most importantly, the V-MB FB demonstrates a methylene blue(MB) utilization of 97.55% at a theoretical capacity of 32.16 Ah L^(-1)(based on the concentration of MB in the electrolyte) because of the high ion conductivity of the membrane, which favors reducing the cost of a battery. the results suggest that the designed porous PBI membranes exhibit a very promising prospect for methylene blue-vanadium flow battery.

关键词： Electrochemical energy storage technology Vanadium-methylene blue flow battery Porous PBI membranes Anti-fouling stability

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Peptide nanotube loaded with a StING agonist,c-di-GMP,enhance cancer immunotherapy against melanoma

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Nano Research 2023年第4期16卷 5206-5215页

作者： Ziyuan Zhang Juan liu Min Xiao Quanfeng Zhang Zhonghua liu Meiyan liu Peng Zhang Youlin Zeng Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province Hunan Normal UniversityChangsha 410081China Laboratory of Chemical Biology and traditional Chinese Medicine Research(Ministry of Education of China) Hunan Normal UniversityChangsha 410081China the National&Local Joint Engineering Laboratory of Animal Peptide Drug Development College of Life SciencesHunan Normal UniversityChangsha 410081China

the activation of the stimulating factor of the interferon gene(StING)pathway can enhance the immune response within the *** diguanylate monophosphate(c-di-GMP)is a negatively charged,hydrophilic StING agonist,however,its effectiveness is limited due to the poor membrane permeability and low ***,we introduced KL-7 peptide derived from Aβamyloid fibrils that can self-assemble to form nanotubes to load and deliver c-di-GMP,which significantly enhanced c-di-GMP’s effectiveness and then exhibited a robust“in situ immunity”to kill melanoma ***-7 peptide nanotube,also called PNt,was loaded with negatively charged c-di-GMP via electrostatic interaction,which prepared a nanocomposite named *** of RAW 264.7 cells(leukemia cells in mouse macrophage)with c-di-GMP-PNt markedly stimulated the secretion of IL-6 and INF-βalong with phospho-StING(Ser365)protein expression,indicating the activation of the StING *** the unilateral flank B16-F10(murine melanoma cells)tumor-bearing mouse model,compared to PNt and cdi-GMP,c-di-GMP-PNt can promote the expression of INF-β,tNF-α,IL-6,and IL-1β.At the same time,up-regulated CD4 and CD8 active t cells kill tumors and enhance the immune response in tumor tissues,resulting in significant inhibition of tumor growth in tumor-bearing *** importantly,in a bilateral flank B16-F10 tumor model,both primary and distant tumor growth can also be significantly inhibited by ***,c-di-GMP-PNt demonstrated no obvious biological toxicity on the main organs(heart,liver,spleen,lung,and kidney)and biochemical indexes of *** summary,our study provides a strategy to overcome the barriers of free c-di-GMP in the tumor microenvironment and c-di-GMP-PNt may be an attractive nanomaterial for anti-tumor immunity.

关键词： cyclic diguanylate monophosphate stimulating factor of the interferon gene(StING) peptide nanotubes in situ immunity tumor immunotherapy