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Study on Catalytic Behavior of Iron-based Catalyst with IITP as Electron Donor in the Polymerization of Butadiene

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Chinese Journal of Polymer Science 2024年第5期42卷 612-619,I0007页

作者： Shi-Liang Xu Ying-Nan Zhao yao yu Qi Yang Li-Hua Na Heng Liu Chun-yu Zhang Xue-Quan Zhang Key Laboratory of Advanced Rubber Material Ministry of EducationSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Shandong Provincial College Laboratory of Rubber Material and Engineering School of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Key Lab of Rubber-Plastics Ministry of Education/Shandong Provincial Key Lab of Rubber-plasticsSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China

In this study,a novel iron-based catalyst system,Fe(acac)3/(isocyanoimino)triptenylphosphorane(IITP)/AlR3,was employed for the synthesis of syndiotactic 1,2-polybutadiene in hexane.This catalyst system exhibits remarkably high catalytic activity,achieving a polymerization activity of 762 kgpolymer·molcatalyst^(-1)·h^(-1)at 50℃with a[BD]/[Fe]molar ratio of 20000.Furthermore,living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene polymerization.These characteristics were well demonstrated by a narrow molecular weight distribution(PDI≈2.0)of the resulting polybutadiene and a linear relationship between-ln(1-c)and polymerization time as well as number average molecular weight and polymer yield.The resultant polymer showed a 1,2-selectivity of approximately 76%and stereoregularity ranging from 62%to 73%(rrrr).Additionally,through kinetic studies on polymerization reaction,an apparent activation energy Ea value of this catalytic system was calculated to be 84.98 kJ·mol^(-1),which suggests that high polymerization temperature favors efficient polymerization.

关键词： Iron catalyst Syndiotactic 1,2-polybutadiene Elastomers Donor Selectivity

Multi-Robot Cooperative Localization: Time-Varying Unobservable Subspace Analysis and Consistent Algorithm Design

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Journal of Systems Science & Complexity 2024年第5期 1937-1955页

作者： HAO Ning HE Fenghua yao yu School of Astronautics Harbin Institute of Technology

This paper investigates the problem of cooperative localization(CL) for a multi-robot system(MRS) under dynamic measurement topology, which involves a group of robots collectively estimating their poses with respect to a common reference frame using ego-motion measurements and robot-to-robot relative measurements. The authors provide a theoretical analysis of the time-varying unobservable subspace and propose a consistent cooperative localization algorithm. First, the authors introduce the relative measurement graph(RMG) to represent the relative pose measurements obtained by the MRS at each instant. Then, the authors derive the local observability matrix over a time interval.An equivalent relationship is established between the local observability matrix and the spectral matrices of the RMG. Moreover, the authors present a method for constructing the unobservable subspace based on the RMG under different topology conditions. Based on this analysis, the authors design a consistent cooperative localization algorithm that satisfies the constraints of the time-varying unobservable subspace. An analytical optimal solution is derived for the constrained optimization problem.Monte Carlo numerical simulations are conducted to demonstrate the consistency and accuracy of the proposed method.

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Transfer of disulfide bond formation modules via yeast artificial chromosomes promotes the expression of heterologous proteins inKluyveromyces marxianus

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mLife 2024年第1期3卷 129-142页

作者： Pingping Wu Wenjuan Mo Tian Tian Kunfeng Song Yilin Lyu Haiyan Ren Jungang Zhou yao yu Hong Lu State Key Laboratory of Genetic Engineering School of Life SciencesFudan UniversityShanghaiChina Shanghai Engineering Research Center of Industrial Microorganisms ShanghaiChina

Kluyveromyces marxianus is a food-safe yeast with great potential for producing heterologous proteins.Improving the yield in K.marxianus remains a challenge and incorporating large-scale functional modules poses a technical obstacle in engineering.To address these issues,linear and circular yeast artificial chromosomes of K.marxianus(KmYACs)were constructed and loaded with disulfide bond formation modules from Pichia pastoris or K.marxianus.These modules contained up to seven genes with a maximum size of 15 kb.KmYACs carried telomeres either from K.marxianus or Tetrahymena.KmYACs were transferred successfully into K.marxianus and stably propagated without affecting the normal growth of the host,regardless of the type of telomeres and configurations of KmYACs.KmYACs increased the overall expression levels of disulfide bond formation genes and significantly enhanced the yield of various heterologous proteins.In high-density fermentation,the use of KmYACs resulted in a glucoamylase yield of 16.8 g/l,the highest reported level to date in K.marxianus.Transcriptomic and metabolomic analysis of cells containing KmYACs suggested increased flavin adenine dinucleotide biosynthesis,enhanced flux entering the tricarboxylic acid cycle,and a preferred demand for lysine and arginine as features of cells overexpressing heterologous proteins.Consistently,supplementing lysine or arginine further improved the yield.Therefore,KmYAC provides a powerful platform for manipulating large modules with enormous potential for industrial applications and fundamental research.Transferring the disulfide bond formation module via YACs proves to be an efficient strategy for improving the yield of heterologous proteins,and this strategy may be applied to optimize other microbial cell factories.

关键词： disulfide bond formation expression of heterologous proteins Kluyveromyces marxianus telomere yeast artificial chromosome

Metal oxide ion gated transistors based sensors

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Science China(Technological Sciences) 2024年第4期67卷 1040-1060页

作者： LI Yang yao yu WANG LeLe WANG LiWei PANG yunCong LUO ZhongZhong ARUNPRABAHARAN Subramanian LIU ShuJuan ZHAO Qiang College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts&Telecommunications(NJUPT)Nanjing 210023China State Key Laboratory of Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts&Telecommunications(NJUPT)Nanjing 210023China Department of Chemical Engineering Polytechnique MontréalMontréalQuébec H3C3J7Canada

Metal oxide ion-gated transistors(MOIGTs)have garnered significant attention within the sensing domain due to their potential for achieving heightened sensitivity while consuming minimal energy across diverse scenarios.By harnessing the advantageous combination of metal oxides'high carrier mobility and facile surface customization,coupled with the potent signal amplification capabilities of ion-gated transistors,MOIGTs offer a promising avenue for discerning biomolecules,overseeing chemical reactions,p H levels,as well as facilitating gas or light determination.Over the past few decades,the MOIGT field has made remarkable strides in refining device physics,enhancing material properties,showcasing robust sensing capabilities,and broadening its application spectrum.These advancements have simultaneously unveiled new challenges and opportunities,necessitating interdisciplinary expertise to fully unlock the commercial potential of MOIGTs.In this comprehensive review,we offer a snapshot of this swiftly evolving technology,delve into its current applications,and provide insightful recommendations for future directions in the coming decade.

关键词： sensors ion gated transistors metal oxide semiconductors biosensors chemosensors pH sensors

Implementation Research and Results of Hypertension Control Strategy and Model in Rural Areas

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Cardiology Discovery 2024年第1期4卷 1-4页

作者： Guozhe Sun Jing Wu Pengyu Zhang yao yu Yingxian Sun Department of Cardiovascular Medicine The First Hospital of China Medical UniversityShenyangLiaoning 110001China National Center for Chronic and Noncommunicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100050China

Hypertension has become a major risk factor for cardiovascular disease(CVD)and premature mortality worldwide,with high prevalence and relatively poor control rate,especially in rural areas.[1]Blood pressure(BP)control in rural areas is the most vulnerable spot in hypertension control and is a key target to reduce cardiovascular and cerebrovascular events and total mortality.Medical workers globally have devoted considerable efforts to solving this problem and some progress has been made[Table 1].[2–6]Our recent study proved that a novel,village doctor-led,multifaceted intervention strategy for BP control was an effective,feasible,and safe method for controlling hypertension in rural China.[6]

关键词： mortality Blood cardiovascular

Advances in mesenchymal stem cells therapy for tendinopathies

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Chinese Journal of Traumatology 2024年第1期27卷 11-17页

作者： Xu-Feng Mao Xi-Qian Zhang Zhe-yu yao Hai-Jiao Mao Department of Orthopaedic Surgery The First Affiliated Hospital of Ningbo UniversityNingbo315010Zhejiang provinceChina

Tendinopathies are chronic diseases of an unknown etiology and associated with inflammation.Mesenchymal stem cells(MSCs)have emerged as a viable therapeutic option to combat the pathological progression of tendinopathies,not only because of their potential for multidirectional differentiation and self-renewal,but also their excellent immunomodulatory properties.The immunomodulatory effects of MSCs are increasingly being recognized as playing a crucial role in the treatment of tendinopathies,with MSCs being pivotal in regulating the inflammatory microenvironment by modulating the immune response,ultimately contributing to improved tissue repair.This review will discuss the current knowledge regarding the application of MSCs in tendinopathy treatments through the modulation of the immune response.

关键词： Mesenchymal stem cells Tendinopathy Immunomodulation Treatment Review

Effect of Feeding Steel Strip Carbon Content on Macrosegregation Distribution in Large Continuous Casting Round Bloom

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An unusual anterior mitral leaflet perforation in a patient with no infective endocarditis:a case report

Dongbei Daxue Xuebao/Journal of Northeastern University 2024年第4期45卷 499-506页

作者： yao, yu-Chao Liu, Zhong-Qiu Rong, Wen-Jie Li, Bao-Kuan School of Metallurgy Northeastern University Shenyang 110819 China

Feeding a cold steel strip into continuous casting（CC）mold is an effective method to improve the center quality of large round bloom. A liquid-columnar-equiaxed solidification three-phase volume averaged solidification model was developed to explore the effect of feeding strip carbon content on solidification structure and macrosegregation distribution of large CC round bloom in this paper. The results show that the carbon content of feeding steel strip has a significant effect on the growth of equiaxed crystals and columnar crystals. Under the condition of both low and high strip carbon contents，the effect of feeding steel strip on increasing equiaxed grain volume fraction will be reduced. The solute concentration and distribution in the casting bloom can be directly affected by regulating the solute concentration of steel strip. The steel strip with 1. 0 times the carbon content of casting steel（rC=1. 0）has the best improvement effect on the large CC round bloom， with the radial extreme difference of carbon content and macrosegregation index of the bloom being 0. 165 7% and 38. 36%，respectively. © 2024 Northeast University. All rights reserved.

关键词： Continuous casting

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Emergency and Critical Care Medicine 2024年第1期4卷 39-41页

作者： Kaiming Wei yu yao Chuanzhen Liu yuan Cao Department of Cardiovascular Surgery Qilu Hospital of Shandong UniversityJinanShandongChina Department of Emergency Medicine Qilu Hospital of Shandong UniversityJinanShandongChina National Key Laboratory for Innovation and Transformation of Luobing Theory The Key Laboratory of Cardiovascular Remodeling and Function ResearchChinese Ministry of EducationChinese National Health Commission and Chinese Academy of Medical SciencesDepartment of CardiologyQilu Hospital of Shandong UniversityJinanShandongChina.

Background:Mitral valve perforation refers to the occurrence of cracks or openings in the structure of the mitral valve,allowing blood to escape through these gaps.Typically,this is caused by infective endocarditis and the most common site is the anterior leaflet.However,it is crucial to explore other potential causes of valve damage,particularly when conventional risk factors are not apparent.Case presentation:We present a case of a middle-aged male patient who developed mitral valve perforation because of aortic valve regurgitation in the absence of infective endocarditis.Conclusion:Exploring such rare cases contributes to a deeper understanding of valvular diseases and enhances clinical decision making for effective management.

关键词： Anterior mitral leaflet Aortic valve Case report Perforation Prolapse Regurgitation

A robust indium-organic framework with open tubular channels for efficient separation of acetylene

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Nano Research 2024年第4期17卷 3139-3146页

作者： Yong-Zhi Li Gang-Ding Wang Fan Xu Qing Yin Danyang Zhao Jiqiu Qi Yanwei Sui Lei Hou yao-yu Wang School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education Shaanxi Key Laboratory of Physico-Inorganic ChemistryCollege of Chemistry&Materials ScienceNorthwest UniversityXi’an 710069China

Considering the tremendous applications and purification requirement of acetylene(C_(2)H_(2)),seeking appropriate adsorbents with high capacity and selectivity is a vital task and remains an enduring challenge.Herein,we designed and synthesized a robust three-dimensional(3D)indium-organic framework([(Me)_(2)NH_(2)][In(L6)_(0.5)(IPA)_(0.5)]·DMA·2H_(2)O(In-L6-IPA,DMA=dimethylammonium,IPA=isopropyl alcohol))featuring two types of one-dimensional(1D)tubular channels.The activated In-L6-IPA displayed high loading for C_(2)H_(2)(104.4 cm^(3)·g^(-1),the second highest value among all reported indium-based metal-organic frameworks(MOFs))and simultaneously selective adsorption for C_(2)H_(2) over CO_(2),C_(2)H_(6),and ethylene(C_(2)H_(4))at 298 K under 100 kPa.Molecular modelling revealed that the porous wall of In-L6-IPA provides more and stronger multiple interactions for C_(2)H_(2) than CO_(2),C_(2)H_(6),and C_(2)H_(4) containing C–H···π,C–H···O,and O···πinteractions.Breakthrough experiments validated the actual separation ability for various ratios of binary C_(2)H_(2)/C_(2)H_(4) and C_(2)H_(2)/CO_(2) mixtures as well as equimolar ternary C_(2)H_(2)/C_(2)H_(4)/CO_(2) and C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6) mixtures with excellent reusability.

关键词： indium-organic framework crystal structure gas adsorption acetylene(C_(2)H_(2))separation