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RsaL is a self-regulatory switch that controls alternative biosynthesis of two AHL-type quorum sensing signals in Pseudomonas aeruginosa PA1201

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mLife 2024年第1期3卷 74-86页

作者： Ya-Wen He Zi-Jing Jin Ying Cui Kai Song Bo Chen lian zhou State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental SciencesSJTU-NLBP Joint R&D Centre for Biopesticides and BiofertilizersSchool of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghaiChina Zhiyuan Innovative Research Centre Student Innovation CentreZhiyuan CollegeShanghai Jiao Tong UniversityShanghaiChina

Pseudomonas aeruginosa is a ubiquitous and metabolically versatile microorganism naturally found in soil and water.It is also an opportunistic pathogen in plants,insects,animals,and humans.In response to increasing cell density,P.aeruginosa uses two acylhomoserine lactone(AHL)quorum-sensing(QS)signals(i.e.,N-3-oxo-dodecanoyl homoserine lactone[3-oxo-C12-HSL]and Nbutanoyl-homoserine lactone[C4-HsL]),which regulate the expression of hundreds of genes.However,how the biosynthesis of these two QS signals is coordinated remains unknown.We studied the regulation of these two QS signals in the rhizosphere strain PA1201.PA1201 sequentially produced 3-oxo-C12-HSL and C4-HSL at the early and late growth stages,respectively.The highest 3-oxo-C12-HSL-dependent elastase activity was observed at the early stage,while the highest C4-HSL-dependent rhamnolipid production was observed at the late stage.The atypical regulator RsaL played a pivotal role in coordinating 3-oxo-C12-HSL and C4-HSL biosynthesis and QS-associated virulence.RsaL repressed las/transcription by binding the-10 and-35 boxes of the lasl promoter.In contrast,RsaL activated rhll transcription by binding the region encoding the 5'-untranslated region of the rhll mRNA.Further,RsaL repressed its own expression by binding a nucleotide motif located in the-35 box of the rsaL promoter.Thus,RsaL acts as a molecular switch that coordinates the sequential biosynthesis of AHL QS signals and differential virulence in PA1201.Finally,C4-HSL activation by RsaL was independent of the Las and Pseudomonas quinolone signal(PQS)QS signaling systems.Therefore,we propose a new model of the QS regulatory network in PA1201,in which RsaL represents a superior player acting at the top of the hierarchy.

关键词： N-3-oxo-dodecanoyl homoserine lactone N-butanoyl-homoserine lactone Pseudomonas aeruginosa quorum sensing RsaL

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A Problem Not to Be Ignored: The Influencing Factors of Mobile Phone Addiction and Its Influence on Sleep Quality

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Health 2024年第5期16卷 459-469页

作者： Zihan Ji lian zhou Department of Occupational Medicine and Environmental Health School of Public Health of Nanjing Medical University Nanjing China Institute of Environment and Health Jiangsu Center for Disease Control and Prevention (Jiangsu Institute of Public Health) Nanjing China

Background and Objective: With the popularity and widespread use of mobile phones, the effects of mobile phone dependence and addiction on individuals’ physical and mental health have attracted more and more attention. The present study aims to analyze the current state of mobile phone addiction and its impact on sleep quality within the population, while also exploring the influence of related factors on sleep quality. Ultimately, this research will provide a scientific foundation for targeted intervention measures and strategies. Methods: A total of 253 permanent residents in Nanjing were randomly selected as study subjects. The Mobile Phone Addiction Index (MPAI) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the degree of smartphone addiction and sleep quality of the study subjects. Body mass index (BMI) was measured according to standardized procedures. Independent sample t-test, Chi-square test, rank sum test and multiple linear regression were used to analyze the correlation between mobile phone addiction and sleep quality, and P Results: 117 people (46.2%) were addicted to mobile phones. Chi-square test showed that the rate of mobile phone addiction in drinking group was significantly higher than that in non-drinking group (P P P P P P P P P P Conclusion: Mobile phone addiction may lead to shorter sleep duration and reduce sleep efficiency. The withdrawal of mobile phone addiction may have a negative impact on sleep quality. According to the characteristics of the population, appropriate comprehensive intervention measures should be taken to build an effective evaluation system, so as to reduce the impact of mobile phone addiction and withdrawal problems on sleep and improve sleep quality.

关键词： Mobile Phone Addiction Influencing Factors Withdrawal Sleep Quality

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The expression mechanism of programmed cell death 1 ligand 1 and its role in immunomodulatory ability of mesenchymal stem cells

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Chinese Journal of Traumatology 2024年第1期27卷 1-10页

作者： Zhuo Chen Meng-Wei Yao Xiang Ao Qing-Jia Gong Yi Yang Jin-Xia Liu Qi-zhou lian Xiang Xu Ling-Jing Zuo Department of Stem Cell&Regenerative Medicine State Key Laboratory of TraumaBurn and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042China College of Basic Medical Sciences Army Medical UniversityChongqing400038China Department of Orthopedics 953 Hospital of PLAShigatse Branch of Xinqiao HospitalArmy Medical UniversityShigatse857000Tibet Autonomous RegionChina Department of Rheumatology and Immunology Daping HospitalArmy Medical UniversityChongqing400042China Department of Obstetrics and Gynecology Chongqing People's HospitalChongqing401121China Department of Medicine Li Ka Shing Faculty of MedicineThe University of Hong KongHong KongChina Department of Nuclear Medicine The First People's Hospital of Yunnan provinceAffiliated Hospital of Kunming University of Science and TechnologyKunming650034China

Programmed cell death 1 ligand 1(PD-L1)is an important immunosuppressive molecule,which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1.The PD-L1 expression disorder plays an important role in the occurrence,development,and treatment of sepsis or other inflammatory diseases,and has become an important target for the treatment of these diseases.Mesenchymal stem cells(MSCs)are a kind of pluripotent stem cells with multiple differentiation potential.In recent years,MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases.Moreover,PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases.In this review,we will summarize the main regulatory mechanism of PD-L1 expression,and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

关键词： PD-L1 MSCs Immunomodulation

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Regional landscape transformation and sustainability of the rural homegarden agroforestry system in the Chengdu Plain,China

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Regional Sustainability 2022年第1期3卷 68-81页

作者： zhou lian HUANG Xueyuan ZHAO Chunmei PU Tiancun ZHANG Lei College of Landscape Architecture Sichuan Agricultural UniversityChengdu611130China

Traditional rural homegarden agroforestry system in the Chengdu Plain of China,called“Linpan”in Chinese,integrates the ecological functions of the landscape with human production activities.Studying the driving mechanisms of rural landscape changes in the Chengdu Plain is of great significance from stakeholders’perspective.Taking the Pidu Linpan Farming System(PLFS)in the suburban area of Chengdu(designated as one of China-Nationally Important Agricultural Heritage Systems in 2020)as a case,this study combined remote sensing image analysis,oral history interviews,and focus group interviews to elucidate the driving forces of landscape changes in the PLFS.The results show that tourism development,traffic accessibility,economic demand,and agricultural heritage protection measure are the main driving forces promoting the stability and maintenance of the traditional homegardens.In contrast,population ageing,land circulation,centralized residence,climate change,and living and recreational need are the forces leading to adverse changes in the traditional homegardens.In addition,these driving forces have led to the gradual abandonment of traditional agricultural activities and critical issues related to rural landscape planning and management.The current research indicates that infrastructure construction and increased traditional agricultural income are considered as the best practices of local stakeholders,promoting the development of the protected homegardens of heritage sites and tourist destinations.Finally,we put forward some suggestions to improve and maintain the traditional rural landscape:(1)establishing a benefit-sharing mechanism;(2)establishing a training system with traditional technology and culture;(3)strengthening infrastructure construction;(4)promoting the development of the agricultural industry;(5)improving the cultural quality of farmers;and(6)establishing a management system with legal effects.This research can provide a basis for the formulation of rural landscape planning and the orderly and heal

关键词： Sustainability Rural landscape Homegardens Agricultural heritage Social ecosystem Chengdu Plain

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Constrained multi-degree reduction of triangular Bézier surfaces

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Applied Mathematics(A Journal of Chinese Universities) 2009年第4期24卷 417-430页

作者： zhou lian WANG Guo-jin Department of Mathematics Zhejiang University Hangzhou 310027 China State Key Laboratory of CAD＆CG Zhejiang University Hangzhou 310027 China

This paper proposes and applies a method to sort two-dimensional control points of triangular Bezier surfaces in a row vector. Using the property of bivariate Jacobi basis functions, it further presents two algorithms for multi-degree reduction of triangular Bezier surfaces with constraints, providing explicit degree-reduced surfaces. The first algorithm can obtain the explicit representation of the optimal degree-reduced surfaces and the approximating error in both boundary curve constraints and corner constraints. But it has to solve the inversion of a matrix whose degree is related with the original surface. The second algorithm entails no matrix inversion to bring about computational instability, gives stable degree-reduced surfaces quickly, and presents the error bound. In the end, the paper proves the efficiency of the two algorithms through examples and error analysis.

关键词： triangular Bezier surface explicit boundary curve constraint corner constraint degree reduction Jacobi polynomial

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Can Rawls＇ Constructivism Avoid the Euthyphro Dilemma？ In Reply to Shafer-Landau

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Frontiers of Philosophy in China 2015年第4期10卷 568-578页

作者： zhou lian School of Philosophy Renmin University of China Beijing 100872 China

In this essay, I consider two challenges implicit in Russ Shafer-Landau’s criticism of constructivists: the realism challenge and the relativism challenge, respectively. I do not try to offer a decisive set of objections to the challenges; instead I argue that some objective versions of constructivism, especially Rawls’s constructivism, are not susceptible to the criticisms.

关键词： Euthyphro dilemma moral realism moral constructivism relativism

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Preliminary Mo isotope data of Phanerozoic clastic sediments from the northern margin of the Yangtze block and its implication for paleoenvironmental conditions

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Chinese Science Bulletin 2009年第5期54卷 822-829页

作者： zhou lian GAO Shan CHRIS Hawkesworth COREY Archer XIE ShuCheng State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China Department of Earth Sciences University of Bristol Bristol BS8 1R J U.K.

Mo isotopes along with Nd isotopes and other geochemical characteristics of the Phanerozoic clastic sediments from the northern margin of the Yangtze block were analyzed by MC-ICP-MS and some other techniques, spanning the period from Cambrian to Jurassic. The δ 98Mo values and εNd(t ) in these sedimets were observed to exhibit a large range of variation (?0.65‰―+1.87‰, ?1.46―?10.90, respec-tively). Specifically, the sample from Late Permian Maokou Formation has relatively positive values in both δ 98Mo and εNd(t ) (+0.97‰, ?1.46, respectively). These elevated values are proposed to relate to the input of a large quantity of H2S and HS- into the contemporaneous seawater by the volcanic eruption of the Emeishan mantle plume. Introduction of these sulfide gases would cause MoO42? to be transferred into MoS24?, favoring the preferential deposition of the heavy Mo isotope as MoS24? and thus leaving a positive Mo isotope value. The sample from Late Permian Changxing Formation has a significantly elevated δ 98Mo value of +1.87‰, in association with the relatively negative εNd(t ) (?10.90) and remain the relatively higher content of both TOC and total sulfur (TS) (1.52%, 2.02%, respectively). This infers the presence of the enhanced primary productivity and high organic burial during the Changxing pe-riod. The production of a huge quantity of HS? and H2S by the sulfate-reducing reaction led to the ex-istence of the elevated seawater δ 98Mo values during the Changxing period. The preliminary Phanero-zoic data reported here allow us to propose that the Mo isotope signature preserved in reductive sediments is related to the regional tectonic settings and the associated environmental conditions, and thus the measurement of δ 98Mo promotes our understanding on the evolution of the paleoenviron-mental event in the Earth history.

关键词：钼同位素古环境显生宙长江

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The environmental index of the rare earth elements in conodonts:Evidence from the Ordovician conodonts of the Huanghuachang Section,Yichang area

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Chinese Science Bulletin 2012年第4期57卷 349-359页

作者： CHEN XiaoHong zhou lian WEI Kai WANG Jin LI ZhiHong Wuhan Institute of Geology and Mineral Resources Wuhan 430223China Geological Processes and Mineral Resources State Key Laboratory of China University of GeosciencesWuhan 430074China

High-resolution microanalysis was performed on conodonts collected from the Huanghuachang section in the Yichang area using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This region is regarded as a standard section for the division and correlation of the Ordovician system in southern China. The results show that the values of (La/Yb)N and (La/Sm)N decrease, while the values of δCe increase as seawater deepens and energy decreases. As the sedimentary environment changes from shallow-water carbonate platform to platform margin to open continental shelf to shelf basin, rare earth element distribution curves gradually transform from a right inclined pattern to a flat pattern to a left inclined pattern and a hat-shaped pattern. The present work proves that the values and distributive patterns of rare earth elements in conodonts correspond with the sedimentary environment, and therefore provide reliable evidence for the application of rare earth element concentrations of biogenic phosphates such as conodonts for palaeoenvironmental reconstructions.

关键词：稀土元素宜昌地区牙形石奥陶系环境指标 LA-ICP-MS 证据黄花

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集约化柑橘种植抑制土壤磷循环微生物活性

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环境科学 2024年第5期45卷 2881-2890页

作者：周连昊曾全超梅唐英泽汪明霞谭文峰中国科学院重庆绿色智能技术研究院重庆400714 中国科学院大学北京101408 华中农业大学资源与环境学院武汉430070

微生物是调节土壤磷循环的关键驱动力.阐明土壤解磷菌的微生物矿化过程对于提高植物养分吸收率和作物产量具有重要意义.通过测定柑橘园与毗邻的自然林地土壤编码碱性磷酸酶基因(phoD)丰度、解磷细菌群落多样性和土壤无机磷组分,探究柑... 详细信息

微生物是调节土壤磷循环的关键驱动力.阐明土壤解磷菌的微生物矿化过程对于提高植物养分吸收率和作物产量具有重要意义.通过测定柑橘园与毗邻的自然林地土壤编码碱性磷酸酶基因(phoD)丰度、解磷细菌群落多样性和土壤无机磷组分,探究柑橘种植对土壤微生物获取磷策略的影响机制.结果表明,柑橘种植导致土壤pH下降,土壤有效磷累积,ω(有效磷)平均值高达112 mg·kg^(−1),显著高于毗邻的自然林地(3.7 mg·kg^(−1)).柑橘种植也会影响土壤磷素组成,柑橘土壤含有较高的可溶态磷(CaCl_(2)-P)、柠檬酸提取态磷(Citrate-P)和矿物结合态磷(HCl-P).自然林地土壤各磷组分均显著低于柑橘土壤,而phoD基因丰度和碱性磷酸酶活性显著高于柑橘土壤.高通量测序结果表明,柑橘土壤解磷细菌Shannon指数(4.61)显著低于自然林地(5.35),群落结构也有别于自然林地.柑橘种植改变了土壤解磷菌的群落组成,自然林地变形菌门的相对丰度显著低于柑橘土壤.土壤有效磷含量与碱性磷酸酶活性呈显著负相关,表明土壤高磷累积抑制土壤解磷细菌的活性.柑橘种植改变了土壤微生物对磷的获取策略,在柑橘园中,土壤微生物主要依赖外源磷,而自然林地土壤微生物主要以微生物分泌碱性磷酸酶矿化有机磷来获取磷的方式满足其生长需求.

关键词：集约化农业柑橘土壤微生物磷循环 phoD基因

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Corrosion behaviors of a new titanium alloy TZNT for surgical implant application in Ringer’s solution

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Rare Metals 2010年第1期29卷 37-44页

作者： LI Jun zhou lian LI Zuochen School of Materials Engineering Shanghai University of Engineering Science Shanghai 201620 China Northwest Institute for Nonferrous Metal Research Xl an 710016 China

A new near α-titanium alloy Ti12.5Zr2.5Nb2.5Ta （TZNT） for surgical implants was designed. The potentiodynamic technique was performed to investigate the corrosion behaviors of TZNT in Ringer＇s solution, and Ti6A14V, Ti6Al7Nb, and TA2 were taken as comparison. The structure of the passive film was analyzed using an X-ray photoelectron spectrometer （XPS）. The results indicate that TZNT possesses better corrosion resistance, when compared with Ti6A14V, Ti6A17Nb, and TA2. The passive film formed on the TZNT surface is composed of oxides, such as TiO2, ZrO2, Nb2O5, and Ta2O5. The elements Zr and Ta are rich, whereas Ti and Nb are poor in the passive film. The addition of Zr, Nb, and Ta with relatively low electrochemical reaction potentials can reduce the anode activity and improve passive properties. Other than that, oxides such as ZrO2, Nb2O5, and Ta2O5 with the nobler equilibrium constants make the passive film more stable.

关键词： titanium alloy surgical implant electrochemistry passive film corrosion resistance

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