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Tough Polymeric Hydrogels Based on Amino Acid Derivative Mediated Dynamic Metal Coordination Bonds

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Chinese Journal of Polymer Science 2024年第10期42卷 1578-1588,I0014页

作者： meng Li meng-Yuan zhang Wu-Xuan Lei Zhu-Ting Lv Qing-Hua Shang Zheng Zhao Jiang-Tao Li yi-Long Cheng Engineering Research Center of Energy Storage Materials and Devices Ministry of EducationSchool of ChemistryXi’an Jiaotong UniversityXi’an710049China Polymer Materials&Engineering Department School of Materials Science&Engineering Chang’an UniversityXi’an710064China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China Department of Nuclear Medicine the First Affiliated Hospital of ChinaXi’an Jiaotong UniversityXi’an710049China

Abstract The development of physically crosslinked hydrogels with excellent mechanical and sensing properties is of importance for expanding the practical applications of intelligent soft hydrogel ***,after copolymerization of hydroxyl-containing amino acid derivative N-acryloyl serine(ASer)with acrylamide(AM),we introduce Zr4+through an immersion strategy to construct metal ion-toughened non-covalent crosslinked hydrogels(with tensile strength of up to 5.73 MPa).It is found that the synergistic coordination of hydroxyl and carboxyl groups with Zr^(4+)substantially increases the crosslinking density of the hydrogels,thereby imparting markedly superior mechanical properties compared to hydroxyl-free Zr^(4+)-crosslinked hydrogels,such as N-acryloyl alanine(AAla)copolymerized with AM hydrogels(with tensile strength of 2.98 MPa)Through the adjustment of the composition of the copolymer and the density of coordination bonds,the mechanical properties of the hydrogels can be modulated over a wide ***,due to the introduction of metal ions and the dynamic nature of coordination bonds,the hydrogels also exhibit excellent sensing performance and good self-recovery properties,paving the way for the development of flexible electronic substrates with outstanding comprehensive performances.

关键词： Hydrogel Amino acid Metal coordination Mechanical performance Flexible sensor

Cross-border E-commerce and China's Exports during the COVID-19 Pandemic

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China & World Economy 2024年第3期32卷 215-242页

作者： yi Che meng Yuan Yan zhang Lin Zhao School of Business East China University of Science and TechnologyChina School of Business Xiangtan UniversityChina School of Economics Shanghai University of Finance and EconomicsChina

China's exports experienced a rapid recovery after the outbreak of the 2019 COVID-19 pandemic.A primary engine was cross-border e-commerce(CBEC)trade,which bucked the downward export trend during the *** exploring the variation in the number of CBEC comprehensive pilot zones across provinces,we identified the causal impact of CBEC on exports using monthly province-product-destination data for 2019 and *** found strong and robust evidence that CBEC contributed to exports during the pandemic by promoting the expansion of incumbent exports(intensive margin)rather than through the expansion of product categories and exporting partners(extensive margin).Specifically,higher pandemic risk suppressed the role of CBEC at the intensive margin while enhancing it at the extensive *** to developed countries benefited more from CBEC,both intensively and *** with final products,a larger number of intermediate products were exported through CBEC after the outbreak of the pandemic.

关键词： China's exports COVID-19 pandemic cross-border e-commerce extensive margin of trade intensive margin of trade

Insights into Euphorbia diversity: Probing the contrasts between Euphorbia fischeriana Steud and Euphorbia ebracteolata Hayata

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Journal of Pharmaceutical Analysis 2024年第5期14卷 775-779页

作者： Kaicheng Du yi zhang Lei Sun Muke Tao Tiantian Zuo Yumeng Wang Zhengfeng zhang Dali meng School of Traditional Chinese Materia Medica Shenyang Pharmaceutical UniversityShenyang110016China NMPA Key Laboratory for Quality Monitoring of Narcotic Drugs and Psychotropic Substances Chongqing Institute for Food and Drug ControlChongqing401121China National Institutes for Food and Drug Control Beijing100050China

In traditional Chinese medicine(TCM),Euphorbia fischeriana Steud(***)and Euphorbia ebracteolata Hayata(***),commonly referred to as“Langdu”,are widely extensively utilized for treating lymphatic tuberculosis and ringworm[1].Both plant species are perennial herbaceous plants mainly distributed in northeastern China,Mongolia,Russia(Siberia),and Republic of Korea[2].There have been many reports on the chemical constituents and pharmacological effects of the two plant species,which has made more and more researchers realize that there may be differences between *** and *** some cases,long-term improper use of herbal medicines can even lead to life-threatening conditions[3,4].Therefore,it is essential to employ an effective technology to differentiate between these two plants based on their chemical constituents and biological activities,so as to reduce the harm caused by the mixing and misuse of medicinal ***,the present paper describes a study of the differences between *** and ***,using untargeted plant metabolomics and biological activity *** study aims to provide valuable insight into their equivalence and potential interchangeability in TCM and clinical medication.

关键词： Euphorbia Siberia northeastern

Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

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National Science Review 2024年第2期11卷 155-167页

作者： Peng He meng-Yang Hu Jin-Hong Li Tian-zhang Qiao yi-Lin Lu Shou-Fei Zhu Frontiers Science Center for New Organic Matter State Key Laboratory and Institute of Elemento-Organic Chemistry Nankai University

Iron catalysts are ideal transition metal catalysts because of the Earths abundant, cheap, biocompatible features of iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively,and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

关键词： spin effect spin-delocalization spin crossover iron-catalysis alkyne hydrosilylation

Comprehensive evaluation of rare case:From diagnosis to treatment of a sigmoid Schwannoma:A case report

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World Journal of Gastrointestinal Oncology 2024年第1期16卷 244-250页

作者： Jing-yi Li Xi-Zhuang Gao Jian zhang Xiang-Zheng meng yi-Xian Cao Kun Zhao Clinical Medical College of Jining Medical University Jining Medical UniversityJining 272000Shandong ProvinceChina Department of Gastroenterology The First People's Hospital of JiningJining 272000Shandong ProvinceChina

BACKGROUND Schwannomas are uncommon tumors originating from Schwann cells,forming the neural *** account for approximately 2%-6%of all mesenchymal tumors and are most commonly identified in peripheral nerve trunks,with rarity in the gastrointestinal *** gastrointestinal locations,the stomach harbors the majority of nerve sheath tumors,while such occurrences in the sigmoid colon are exceptionally *** SUMMARY This study presented a clinical case involving a 60-year-old female patient who,during colonoscopy,was diagnosed with a submucosal lesion that was later identified as a nerve sheath *** patient underwent surgical resection,and the diagnosis was confirmed through *** study highlighted an exceptionally uncommon occurrence of a nerve sheath tumor in the sigmoid colon,which was effectively managed within our ***,a comprehensive review of relevant studies was *** The preoperative diagnosis of nerve sheath tumors poses challenges,as the definitive diagnosis still relies on pathology and *** categorized as benign,these tumors have the potential to demonstrate malignant ***,the optimal treatment approach entails the complete surgical excision of the tumor,ensuring the absence of residual lesions at the margins.

关键词： Schwannoma Gastrointestinal stromal tumors Treatment Sigmoid colon Case report

Self-assembly of perovskite nanocrystals:From driving forces to applications

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Journal of Energy Chemistry 2024年第1期88卷 561-578,I0013页

作者： yi Li Fei zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell *** review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are ***,we summarize the collective optoelectronic properties and application areas of perovskite superlattice ***,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

关键词： Self-assembly Metal halide perovskite Nanocrystals Driving forces

Molecular Ferroelastic Induced by Mono-/Double-Protonation Strategy

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Chinese Journal of Chemistry 2024年第15期42卷 1706-1712页

作者： Jia-Qi Luo meng-meng Lun Qiang-Qiang Jia Zhi-Jie Wang Hai-Feng Lu yi zhang Da-Wei Fu Institute for Science and Applications of Molecular Ferroelectrics Key Laboratory of the Ministry of Education for Advanced Catalysis MaterialsZhejiang Normal UniversityJinhuaZhejiang 321004China Ordered Matter Science Research Center Jiangsu Key Laboratory for Science and Applications of Molecular FerroelectricsSoutheast UniversityNanjingJiangsu 211189China

Molecular ferroelastics with the natural features of mechanical flexibility and switchable spontaneous strain have attracted widespread attention in the scientific community due to their potential applications in tunable gratings,flexible memorizers,strain sensors,and intelligent ***,most designs of molecular ferroelastics remain in the stage of blind exploration,posing a challenge to achieve a functional ferroelastic more ***,we have successfully obtained a molecular ferroelastic,[Me_(2)NH(CH_(2))_(2)NH_(3)](ReO_(4))_(2)(Me_(2)NH(CH_(2))_(2)NH_(3)=N,N-dimethylethylenediammonium),under the guidance of the mono-/double-protonation ***_double-protonated[Me_(2)NH(CH_(2))_(2)NH_(3)](ReO_(4))_(2) undergoes a paraelastic-ferroelastic phase transition with the Aizu notation of 2/mFi at 322 ***,the theoretical calculation and experimental measurement simultaneously show that[Me_(2)NH(CH_(2))_(2)NH_(3)](ReO_(4))_(2) possesses good mechanical flexibility,because its elastic modulus(E)of 8.26 GPa and hardness(H)of 0.45 GPa are smaller than the average values of organic crystals(E of 12.05 GPa and H of 0.5 GPa),which makes it promising to apply in wearable pressure sensors,implantable medical sensors,high-precision tuners,*** work further enriches the molecular ferroelastic family and demonstrates that mono-/double-protonation is one of the effective molecular modification strategies for designing ferroelastics.

关键词： Molecular crystal Ferroelastic Mono-/double-protonation Mechanical flexibility Phase transition Crystal engineering Computational chemistry Molecular dynamics

Establishment of microneurovascular units in alginate hydrogel microspheres to reveal the anti-hypoxic effect of salidroside

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Journal of Pharmaceutical Analysis 2024年第6期14卷 926-929页

作者： Shiyu Chen Yuxuan Li yingrui zhang Hongren Yao Tong Xu yi zhang Jin-Ming Lin Xian-Li meng State Key Laboratory of Southwestern Chinese Medicine Resources Innovative Institute of Chinese Medicine and PharmacyChengdu University of Traditional Chinese MedicineChengdu611137China Beijing Key Laboratory of Microanalytical Methods and Instrumentation Department of ChemistryKey Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology(Ministry of Education)Tsinghua UniversityBeijing100084China School of Ethnic Medicine Chengdu University of Traditional Chinese MedicineChengdu611137China

Microneurovascular units(mNVUs),comprising neurons,micro-glia,and blood-brain barrier(BBB)endothelial cells,are pivotal to the central nervous system and are associated with cerebral hypoxia and brain *** hypoxia triggers microglial overactivity,causing inflammation,neuronal injury,and disruption of the BBB[1].Salidroside(Sal),a key compound in Tibetan medicine Rhodiola crenulata,mitigates hypoxia-induced metabolic disorders and neuronal damage by preserving mitochondrial function[2].

关键词： injuries preserving Tibetan

Cooperative User-Scheduling and Resource Allocation Optimization for Intelligent Reflecting Surface Enhanced LEO Satellite Communication

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China Communications 2024年第2期21卷 227-244页

作者： meng meng Bo Hu Shanzhi Chen Jianyin zhang State Key Lab of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Lab of Wireless Mobile Communication China Academy of Telecommunication TechnologyBeijing 100191China Research Institute of China Mobile Beijing 100053China

Lower Earth Orbit(LEO) satellite becomes an important part of complementing terrestrial communication due to its lower orbital altitude and smaller propagation delay than Geostationary satellite. However, the LEO satellite communication system cannot meet the requirements of users when the satellite-terrestrial link is blocked by obstacles. To solve this problem, we introduce Intelligent reflect surface(IRS) for improving the achievable rate of terrestrial users in LEO satellite communication. We investigated joint IRS scheduling, user scheduling, power and bandwidth allocation(JIRPB) optimization algorithm for improving LEO satellite system *** optimization problem of joint user scheduling and resource allocation is formulated as a non-convex optimization problem. To cope with this problem, the nonconvex optimization problem is divided into resource allocation optimization sub-problem and scheduling optimization sub-problem firstly. Second, we optimize the resource allocation sub-problem via alternating direction multiplier method(ADMM) and scheduling sub-problem via Lagrangian dual method ***, we prove that the proposed resource allocation algorithm based ADMM approaches sublinear convergence theoretically. Finally, we demonstrate that the proposed JIRPB optimization algorithm improves the LEO satellite communication system throughput.

关键词： convex optimization intelligent reflecting surface LEO satellite communication OFDM