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Application of wastewater-based epidemiological monitoring of COVID-19 for disease surveillance in the city

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 81-87页

作者： Heng chen Zhenhua chen Liwen Hu Fengzhu Tang Dan Kuang Jiayi Han Yao Wang Xiao Zhang Yue cheng Jiantong Meng Rong Lu Lan Zhang chengdu Workstation for Emerging Infectious Disease Control and Prevention Chinese Academy of Medical SciencesChengdu 610047China chengdu Center for Disease Control and Prevention Chengdu 610047China National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Beijing 100050China National Institute of Environmental Health Chinese Center for Disease Control and PreventionBeijing 100050China

Wastewater-based surveillance serves as a supplementary approach to clinical surveillance of COVID-19 during the *** study aimed to track the prevalence of the disease and the viral genetic variability through wastewater-based surveillance in the post-epidemic *** January to December 2023,samples were collected from the influent lines of two wastewater treatment plants(WWTPs),concentrated using PEG8000,and subjected to detection of the target genes ORF 1ab and N of SARS-CoV-2 via reverse transcriptional quantitative PCR(RT-qPCR).For next-generation sequencing(NGS),high-quality samples from both wastewater and clinical patients were *** analysis were performed using R software to evaluate the correlation between the SARSCoV-2 RNA concentrations in wastewater and positive rate of reported cases,indicating a positive *** diversity patterns of SARS-CoV-2 in wastewater resembled those in the patient source based on Principal Coordinates Analysis(PCoA)with three clusters for different *** rise of RNA concentration in wastewater indicates the growth of cases and the emergence of new variants,serving as an early warning of potential viral mutations,disease outbreaks even possible ***,the genomic surveillance of wastewater could help identify new variants that may not be captured through population monitoring,especially when sample sizes are ***,surveillance of SARS-CoV-2 in municipal wastewater has emerged as a reliable,earlywarning monitoring system for COVID-19 in the post-epidemic era.

关键词： Wastewater-based epidemiology Monitoring COVID-19 Post-epidemic era

Nanomedicine Disrupts Stromal Barriers to Augment Drug Penetration for Improved Cancer Therapy

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Chinese Journal of Chemistry 2024年第10期42卷 1175-1189页

作者： Guo-Feng Luo Wei-Hai chen Xian-Zheng Zhang state Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei KeyLaboratory of StomatologySchool&Hospital of StomatologyWuhan UniversityWuhanHubei 430079China Key Laboratoryof Biomedical Polymers of Ministry of Education&Departmentof Chemistry Wuhan UniversityWuhanHubei 430072China

Tumor stroma composing diverse extracellular matrixes(ECM)and stromal cells shapes a condensed physical barrier,which severely hampers the efficient accessibility of nanomedicine to tumor cells,especially these deep-seated in the core of *** barrier significantly compromises the antitumor effects of drug-loaded nanomedicine,revealing the remarkable importance of disrupting stromal barrier for improved tumor therapy with deep penetration *** achieve this goal,various nanoparticle-based strategies have been developed,including direct depleting ECM components via delivering anti-fibrotic agents or targeting stromal cells to suppress ECM expression,dynamic regulation of nanoparticles’physicochemical properties(i.e.,size,surface charge,and morphology),mechanical force-driven deep penetration,natural/biomimetic self-driven nanomedicine,and transcytosis-inducing *** these nanostrategies were systemically summarized in this review,and the design principles for obtaining admirable nanomedicine were *** the rapid development of nanotechnology,elaborate design of multifunctional nanomedicine provides new opportunities for overcoming the critical stromal barriers to maximize the therapeutic index of various therapies,such as chemotherapy,photodynamic therapy,and immunotherapy.

关键词： Nanomedicine Tumor stroma Deep penetration Enhanced drug perfusion Cancer therapy Drug carriers Biomaterials Nanotechnology

Using Copula functions to predict climatic change impacts on floods in river source regions

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Advances in Climate Change Research 2024年第3期15卷 406-418页

作者： Ting-Xing chen Hai-Shen LYU Robert HORTON Yong-Hua ZHU Ren-Sheng chen Ming-Yue SUN Ming-Wen LIU Yu LIN The National Key Laboratory of Water Disaster Prevention College of Hydrology and Water ResourcesHohai UniversityNanjing 2098China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China Departmentof Agronomy lowa State UniversityAmes IA5oollUSA qilian Alpine Eology and Hydrology Research Station Northwest Instiuteof Eco-Environmentand ReourcesChinese Academy of SciencesLanzhou0000 China

Flood frequency in river source regions is significantly affected by rainfall and snowmelt as part of climatic changes.A traditional univariate flood frequency analysis cannot reflect the complexity of floods,and when used in isolation,it can only underestimate flood *** effective flood prevention and mitigation,it is essential to consider the combined effects of precipitation and *** functions can effectively quantify the joint distribution relationship between floods and their associated variables without restrictions on their distribution *** study uses copula functions to consider a multivariate probability distribution model of flood peak flow(q)with cumulative snowmelt(CSm)and cumulative precipitation(CPr)for the Hutubi River basin located in northern Xinjiang,*** joint frequencies of rainfall and snowmelt floods are predicted using copula models based on the Coupled Model Intercomparison Project Phase 6 *** results show that q has a significant positive correlation with 24-d CSm(r=0.559,p=0.002)and 23-d CPr(r=0.965,pquency will increase in the future,and mid-(2050e2074)and long-term(2075e2099)floods will be more severe than those in the near-term(2025e2049).The probability of flood occurrence is higher under the SSP2-4.5 and SSP1-2.6 scenarios than under *** during the historical period(1990e2014)led to extreme floods,and increasing future precipitation trends are found to be *** increases with rising temperatures and occurs earlier than estimated,leading to an earlier flood period in the basin and more frequent snowmelt *** q under the joint return period is larger than that during the same univariate return *** difference indicates that neglecting the interaction between precipitation and snowmelt for floods leads to an underestimation of the flood risk(with underestimations ranging from 0.3%to 22%).The underestimations decrease with an increase

关键词： Climate change Flood frequency Copula CMIP6 River source regions

qoS-Aware Computation Offloading in LEO Satellite Edge Computing for IoT:A Game-Theoretical Approach

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Chinese Journal of Electronics 2024年第4期33卷 875-885页

作者： Ying chen Jintao HU Jie ZHAO Geyong MIN School of Computer Science Beijing Information Science and Technology University University of Exeter

Low earth orbit(LEO) satellite edge computing can overcome communication difficulties in harsh environments, which lack the support of terrestrial communication infrastructure. It is an indispensable option for achieving worldwide wireless communication coverage in the future. To improve the quality-of-service(qoS) for Internet-of-things(IoT) devices, we combine LEO satellite edge computing and ground communication systems to provide network services for IoT devices in harsh environments. We study the qoS-aware computation offloading(qCO) problem for IoT devices in LEO satellite edge computing. Then we investigate the computation offloading strategy for IoT devices that can minimize the total qoS cost of all devices while satisfying multiple constraints, such as the computing resource constraint, delay constraint, and energy consumption constraint. We formulate the qoSaware computation offloading problem as a game model named qCO game based on the non-cooperative competition game among IoT devices. We analyze the finite improvement property of the qCO game and prove that there is a Nash equilibrium for the qCO game. We propose a distributed qoS-aware computation offloading(DqCO) algorithm for the qCO game. Experimental results show that the DqCO algorithm can effectively reduce the total qoS cost of IoT devices.

关键词： Satellites Costs Computational modeling Low earth orbit satellites quality of service Games Nash equilibrium

Supported Atomically Dispersed Pd Catalyzed Direct Alkoxylation and Allylic Alkylation

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Chinese Journal of Chemistry 2024年第7期42卷 719-724页

作者： Ruixuan qin Ziwen chen qingyuan Wu Nanfeng Zheng Pengxin Liu New Cornerstone Science Laboratory State Key Laboratory for Physical Chemistry of Solid SurfacesCollaborative Innovation Center of Chemistry for Energy Materialsand National&Local Joint Engineering Research Center of Preparation Technology of NanomaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamenFujian 361005China Innovation Laboratry for Scences and Technoogies of Energy Materials of Fujan Province(IKKM) Xiamen Fujian 361102China School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China Fujian Key Laboratory of Rare-earth Functional Materials Fujian Shanhai Collaborative Innovation Center of Rare-earth Functional MaterialsLongyanFujian 366300China

A new approach to allylic alkylation is realized using an atomically dispersed palladium catalyst(Pd1/TiO2-EG).Unlike conventional methods that require derivation of substrates and utilization of additives,this method allows for direct allylic alkylation from allylic alcohols,producing H2O as the sole *** catalyst's high efficiency is attributed to the local hydrogen bonding at the or-ganic-inorganic interface(Pd-EG interface),facilitating hydroxyl group activation forη3π-allyl complex *** system demonstrates successful direct C—O and C—C coupling reactions with high selectivity,requiring no *** study highlights the potential of supported atomically dispersed catalysts for greener and more efficient catalysis,meanwhile,offers unique insights into the distinct behavior of atomically dispersed catalysts in comparison to homogeneous or nanoparticle-based catalysts.

关键词： Atomically dispersed catalyst Alkylation C—C coupling Organic-inorganic Interface Hydrogen bond Tsuji-Trost reaction Green catalysis

Dielectric metasurface evolution from bulk to monolayer by strong coupling of quasi-BICs for second harmonic boosting

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Photonics Research 2024年第4期12卷 784-792页

作者： YINONG XIE qIANTING chen JIN YAO XUEYING LIU ZHAOGANG DONG JINFENG ZHU Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology Xiamen UniversityXiamen 361005China Shenzhen Research Institute of Xiamen University Shenzhen 518057China Department of Electrical Engineering City University of Hong KongHong Kong 999077China Institute of Materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore

2D materials are promising candidates as nonlinear optical components for on-chip devices due to their ultrathin structure. In general, their nonlinear optical responses are inherently weak due to the short interaction thickness with light. Recently, there has been great interest in using quasi-bound states in the continuum (q-BICs) of dielectric metasurfaces, which are able to achieve remarkable optical near-field enhancement for elevating the second harmonic generation (SHG) emission from 2D materials. However, most studies focus on the design of combining bulk dielectric metasurfaces with unpatterned 2D materials, which suffer considerable radiation loss and limit near-field enhancement by high-quality q-BIC resonances. Here, we investigate the dielectric metasurface evolution from bulk silicon to monolayer molybdenum disulfide (MoS2), and discover the critical role of meta-atom thickness design on enhancing near-field effects of two q-BIC modes. We further introduce the strongcoupling of the two q-BIC modes by oblique incidence manipulation, and enhance the localized optical field on monolayer MoS2dramatically. In the ultraviolet and visible regions, the MoS2SHG enhancement factor of our design is 105times higher than that of conventional bulk metasurfaces, leading to an extremely high nonlinear conversion efficiency of 5.8%. Our research will provide an important theoretical guide for the design of high-performance nonlinear devices based on 2D materials.

关键词： monolayer harmonic quasi

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SOME PROPERTIES OF THE INTEGRATION OPERATORS ON THE SPACES F(p,q,s)

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Acta Mathematica Scientia 2024年第1期44卷 173-188页

作者：陈家乐 School of Mathematics and Statistics Shaanxi Normal UniversityXi’an710119China

We study the closed range property and the strict singularity of integration operators acting on the spaces F(p,pα-2,s).We completely characterize the closed range property of the Volterra companion operator I_(g)on F(p,pα-2,s),which generalizes the existing results and answers a question raised in[***,Integral Equations Operator Theory,69(2011),no.1,87-99].For the Volterra operator J_(g),we show that,for 0<α≤1,J_(g)never has a closed range on F(p,pα-2,s).We then prove that the notions of compactness,weak compactness and strict singularity coincide in the case of J_(g)acting on F(p,p-2,s).

关键词： integration operator closed range property strict singularity

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High-Entropy Ceramics ReVO4 and Microwave Dielectric Properties

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Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society 2024年第9期52卷 2907-2914页

作者： chen D. Mo C. Nong L. Cui H. Wang Z. Liu L. Li C. Guangxi University Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices College of Material Science and Engineering Guilin University of Technology Guangxi Guilin 541004 China Guangxi Key Laboratory of Embedded Technology and Intelligent System Guilin University of Technology Guilin 541004 China

Introduction Microwave dielectric ceramics are widely used in microwave frequency (i.e., 300 MHz–300 GHz) circuits as communication electronic components such as resonators, filters, and antennas. The dielectric permittivity (εr), quality factor (q×f) and the temperature coefficient of resonant frequency (τf) are the main performance index to measure the quality of microwave dielectric ceramics. However, there is a constraint relationship between the performance parameters. In general, the giant εr may cause a large dielectric loss and a low q×f, and the volatility of εr originates an enormous τf value. Therefore, materials with superior intrinsic microwave dielectric properties are rare. The existing methods of controlling microwave dielectric properties mainly include ion substitution, composite control, laminated control and non-stoichiometric ratio control. These methods often require sacrificing one parameter to satisfy other parameters. High-entropy strategy is a novel regulation method used in inorganic materials. High-entropy ceramics refer to a ceramic system with a configuration entropy (Sc) of 1.5R. The high-entropy effect, sluggish diffusion effect, lattice distortion effect and synergy in components (i.e., cocktail effect) are four special effects of high-entropy ceramics. The high-entropy strategy shows a great potential in dielectric ceramics due to these unique effects. In this paper, high-entropy strategy was used to design rare-earth vanadate ceramics. The impact of high-entropy structure on the microwave dielectric properties was investigated. Methods High-entropy ceramics of ReVO4 were synthesized by a solid-phase method with high-purity rare earth oxides (Re2O3 with a purity of > 99.9%) and V2O5. The ceramics with different chemical formulas (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)VO4, (La0.2Ce0.2Nd0.2Sm0.2 Gd0.2)VO4, and (La0.2Ce0.2Nd0.2Sm0.2Y0.2)VO4, were denoted as Eu-5RVO, Gd-5RVO, and Y-5RVO, respectively. The raw materials were weighed according to a s

关键词： dielectric properties high-entropy ceramic microwave frequency vanadate zircon structure

地壳浅部S波速度结构的多频接收函数两步反演法及其在中国东北盆-山构造区的应用

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中国科学：地球科学 2024年第3期54卷 708-724页

作者：杨睿豪王旭陈凌冯铭业陈棋福中国科学院地质与地球物理研究所岩石圈演化国家重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院地质与地球物理研究所中国科学院地球与行星物理重点实验室北京100029

地壳浅部(<10km)速度模型既是地壳结构与变形研究和资源勘探前景评估的基础,又可为壳幔深部结构成像等研究提供先验信息.针对区域尺度结构,被动源方法相比主动源方法具有明显优势.被动源方法中,基于接收函数和/或体波振幅比的成像方法... 详细信息

地壳浅部(<10km)速度模型既是地壳结构与变形研究和资源勘探前景评估的基础,又可为壳幔深部结构成像等研究提供先验信息.针对区域尺度结构,被动源方法相比主动源方法具有明显优势.被动源方法中,基于接收函数和/或体波振幅比的成像方法由于具有较高空间分辨率,近年来受到广泛关注.然而,盆地松散沉积层内部的反射混响常导致此类方法表现出较强的多解性及不确定性,限制了其应用.因此,本文提出一种基于多频径向接收函数波形及其与垂向接收函数振幅比的两步反演法,以约束地壳浅部S波速度结构.理论测试表明,两步反演策略能有效降低反演多解性、提高结果稳定性.将该方法应用于一条横跨中国东北沉积盆地的线性地震台阵数据,获得了地壳浅部S波速度精细结构图像.结果显示,盆地与山地地壳浅部结构差异显著:二连盆地浅部(<1.0km)和松辽盆地浅部(<2.5km)速度较低(<2.8km s^(-1)),反映低速沉积层;松辽盆地7km以深地壳速度较高(3.4~3.8km s^(-1)),可能反映早白垩世镁铁质岩浆侵入体.此外,成像结果中速度异常分布与盆地内大型断裂、隆起及沉积凹陷等构造的地表位置吻合,速度异常延深深度也与已有地震勘探结果相吻合.这些观测表明,两步反演法能有效约束松散沉积盆地S波速度随深度变化特征,并实现区域尺度地壳浅部结构高精度成像.

关键词：接收函数频率依赖性两步反演地壳浅部S波速度结构松散沉积盆地

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