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Access to High-molecular-Weight Polyethylenes through High Temperature Ethylene Polymerization Catalysed by Ethylene-Bridged ansa-(3-R-Cyclopentadienyl)(Fluorenyl) Zirconocene Complexes

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Chinese Journal of Polymer Science 2024年第1期42卷 42-51,I0007页

作者： Bo Li Haiyan Ma Jiling Huang Shanghai Key laboratory of Functional Materials Chemistry and laboratory of Organometallic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of C1-symmetric ethylene-bridged ansa-(3-R-cyclopentadienyl)(fluorenyl) metallocene complexes(Zr: 1-5;Hf: 6) have been synthesized, characterized and investigated as catalyst precursors for the high temperature ethylene polymerization. Using methylaluminoxane(MAO) as the cocatalyst, zirconium complexes 1-5 bearing a bulky substituent on the 3-position of the cyclopendienyl ring showed high catalytic activities up to 1.48×10^(7) g PE·mol_(Zr)^(-1)·h^(-1) toward the polymerization of ethylene and afforded polyethylenes with high molecular weights(1.49×10^(5)-6.31×10^(5) g/mol), meanwhile exhibting great thermal stability at high temperatures up to 120 ℃ together with a long catalytic life time up to 2 h. By adopting low Al/Zr ratios, such as 125, polyethylenes with ultra high molecular weights up to 2.86×106 g/mol were obtained. It is worthy of noting that zirconium complexes 1-4 bearing a substituent with an aryl pendant showed temperature-dependent activities, which increased rapidly with the increase of polymerization temperature, thus weak interaction of the pendent aryl group with the cationic active center is proposed to account for the very low activities displayed at low temperatures. In contrast to zirconocene complexes 1-5, hafnocene complex 6 only displayed very low catalytic activities toward the polymerization of ethylene and afforded polyethylenes with molecular weights ten times smaller than those obtained by zirconocene complexes 1-5. Zirconocene complexes 1-5 were also able to catalyse the polymerization of propylene at high temperatures, but only afforded waxes with low molecular weights.

关键词： ansa-Metallocene Ethylene Propylene Polymerization High temperature

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Tripartite motif-containing protein 11(TRIM11):a novel weapon against Alzheimer’s disease

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Signal Transduction and Targeted Therapy 2024年第2期9卷 339-340页

作者： Yichu Fu Bi Zhang Jianfeng Liu College of Life Science and Technology Key Laboratory of Molecular Biophysics of MOEHuazhong University of Science and TechnologyWuhanHubei 430074China

In a recent study published in Science,Zhang et *** that tripartite motif-containing(TRIM)protein 11(TRIM11)exhibited strong inhibition on tau aggregation,which is a pathological characteristic of tauopathies including Alzheimer’s disease(AD).1 This makes TRIM11 a promising novel target for the treatment of AD and other tauopathies.

关键词： Alzheimer tau TRIM

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A practical guide for fast implementation of SNARE-mediated liposome fusion

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biophysics Reports 2024年第1期10卷 31-40页

作者： Shen Wang Cong Ma Key laboratory of molecular biophysics of the Ministry of Education College of Life Science and TechnologyHuazhong University of Science and Technology

Soluble N-ethylmaleimide-sensitive factor attachment protein receptor(SNAER) family proteins are the engines of most intra-cellular and exocytotic membrane fusion pathways(Jahn and Scheller 2006).Over the past two decades, in-vitro liposome fusion has been proven to be a powerful tool to reconstruct physiological SNARE-mediated membrane fusion processes(Liu et al. 2017). The reconstitution of the membrane fusion process not only provides direct evidence of the capability of the cognate SNARE complex in driving membrane fusion but also allows researchers to study the functional mechanisms of regulatory proteins in related pathways(Wickner and Rizo 2017). Heretofore, a variety of delicate methods for in-vitro SNARE-mediated liposome fusion have been established(Bao et al. 2018;Diao et al. 2012; Duzgunes 2003; Gong et al. 2015; Heo et al. 2021; Kiessling et al. 2015; Kreye et al.2008; Kyoung et al. 2013; Liu et al. 2017; Scott et al. 2003). Although technological advances have made reconstitution more physiologically relevant, increasingly elaborate experimental procedures, instruments, and data processing algorithms nevertheless hinder the non-experts from setting up basic SNARE-mediated liposome fusion assays. Here, we describe a low-cost, timesaving, and easy-to-handle protocol to set up a foundational in-vitro SNARE-mediated liposome fusion assay based on our previous publications(Liu et al. 2023; Wang and Ma 2022). The protocol can be readily adapted to assess various types of SNARE-mediated membrane fusion and the actions of fusion regulators by using appropriate alternative additives(e.g., proteins, macromolecules, chemicals, etc.). The total time required for one round of the assay is typically two days and could be extremely compressed into one day.

关键词： Liposome fusion SNARE In-vitro reconstitution Protocol

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Wood of trees:Cellular structure,molecular formation,and genetic engineering

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Journal of Integrative Plant Biology 2024年第3期66卷 443-467页

作者： Yingying Zhu Laigeng Li State Key laboratory of Herbage Improvement and Grassland Agro-ecosystems and College of Ecology Lanzhou UniversityLanzhou 730000China National Key laboratory of Plant molecular Genetics CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032China

Wood is an invaluable asset to human society due to its renewable nature,making it suitable for both sustainable energy production and material ***,wood derived from forest trees plays a crucial role in sequestering a significant portion of the carbon dioxide fixed during photosynthesis by terrestrial ***,with the expansion of the global population and ongoing industrialization,forest coverage has been substantially decreased,resulting in significant challenges for wood production and *** production practices have changed away from natural forests toward plantation ***,understanding the underlying genetic mechanisms of wood formation is the foundation for developing high-quality,fast-growing plantation *** ideal forest trees for wood production using genetic technologies has attracted the interest of *** studies have been carried out in recent years on the molecular,genetic,and cell-biological mechanisms of wood formation,and considerable progress and findings have been *** studies and findings indicate enormous possibilities and prospects for tree *** review will outline and assess the cellular and molecular mechanisms of wood formation,as well as studies on genetically improving forest trees,and address future development prospects.

关键词： cambium cell wall Populus wood formation xylem

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taBOX: A water-soluble tetraanionic rectangular molecular container for conjugated molecules and taste masking for berberine and palmatine

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Chinese Chemical Letters 2024年第5期35卷 175-178页

作者： Qihan Lin Jiabin Xing Yue-Yang Liu Gang Wu Shi-Jia Liu Hui Wang Wei Zhou Zhan-Ting Li Dan-Wei Zhang Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China

A water-soluble macrocycle that bears four carboxylate anions has been designed and prepared,which forms a rectangular cavity that can efficiently encapsulate discrete electron-deficient aromatic compounds,including berberine and *** macrocycle is revealed to be highly biocompatible and able to inhibit the bitter taste of the two drugs.

关键词： Macrocycle Multianion molecular container molecular recognition Bitter taste masking

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Mechanisms underlying key agronomic traits and implications for molecular breeding in soybean

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Journal of Genetics and Genomics 2024年第4期51卷 379-393页

作者： Chao Fang Haiping Du Lingshuang Wang Baohui Liu Fanjiang Kong Guangdong Key laboratory of Plant Adaptation and molecular Design Guangzhou Key Laboratory of Crop Gene EditingInnovative Center of Molecular Genetics and EvolutionSchool of Life SciencesGuangzhou UniversityGuangzhouGuangdong 510006China

Soybean(Glycine max[L.]Merr.)is an important crop that provides protein and vegetable oil for human *** soybean is a photoperiod-sensitive crop,its cultivation and yield are limited by the photoperiodic conditions in the *** contrast to other major crops,soybean has a special plant architecture and a special symbiotic nitrogen fixation system,representing two unique breeding ***,flowering time,plant architecture,and symbiotic nitrogen fixation are three critical or unique yielddetermining *** review summarizes the progress made in our understanding of these three critical yield-determining factors in ***,we propose potential research directions to increase soybean production,discuss the application of genomics and genomic-assisted breeding,and explore research directions to address future challenges,particularly those posed by global climate changes.

关键词： Soybean Grain yield Flowering time Plant architecture Nodulation Symbiotic nitrogen fixation Genome study

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Catalysis by subsurface metal atoms in Al(001) through electron transfer

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National Science Review 2024年第4期11卷 12-13页

作者： Bo Sun Ding Ma Beijing National laboratory for molecular Science New Cornerstone Science Laboratory College of Chemistry and Molecular Engineering Peking University

Heterogeneous catalysis plays a crucial role in the chemical industry, which has evolved from the investigation of chemisorption to an electronic structure[1]. Diverse strategies, such as alloying,doping, and confining, have been applied to enhance the catalytic properties of active sites through electronic modulation. The electron transfer between active sites and substrates profoundly influences catalytic activity [2].

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Recent advances in the synthesis and application of N-heterocyclic carbene-based molecular cages

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Science China Chemistry 2024年第5期67卷 1510-1523页

作者： Qiongjie Chai Lixin Duan Yanzhe Ma Tianheng Hou Tao Tu Shanghai Key laboratory of molecular Catalysis and Innovative Materials Department of ChemistryFudan UniversityShanghai 200438China State Key laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

N-Heterocyclic carbene(NHC)-based cages have emerged as a prominent and dynamic research area within the research field of chemistry. Leveraging the distinctive electronic and steric properties of NHC ligands, the design, synthesis, and application of these corresponding cages have garnered substantial scholarly interest. In recent years, we have witnessed the successful fabrication of diverse NHC-based cages through a range of synthetic methodologies, which hold significant potential for applications in molecular recognition and catalysis. In this review, we delve into the foundational synthetic strategies that underlie the creation of NHC-based cages, employing approaches encompassing metal–NHC chelation, coordination assembly,and covalent bonding. Additionally, we compile the diverse applications of these cages within catalytic processes and molecular recognition. Lastly, we shed light on the current limitations of synthesis and outline future trends in the development of NHCbased cages.

关键词： N-heterocyclic carbene molecular cages supramolecular chemistry synthetic strategies applications

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Simple and robust 3D MINFLUX excitation with a variable phase plate

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Light(Science & Applications) 2024年第7期13卷 1354-1363页

作者： Takahiro Deguchi Jonas Ries European molecular Biology laboratory Cell Biology and BiophysicsHeidelbergGermany. Max Perutz Labs Vienna Biocenter Campus(VBC)ViennaAustria. University of Vienna Center for Molecular BiologyDepartment of Structural and Computational BiologyViennaAustria. University of Vienna Faculty of PhysicsViennaAustria

MINFLUX has achieved extraordinary resolution in superresolution imaging and single fluorophore *** is based on localizing single fluorophores by rapid probing with a patterned beam that features a local intensity *** implementations,however,are complex and expensive and are limited in speed and ***,we show that a combination of an electro-optical modulator with a segmented birefringent element such as a spatial light modulator produces a variable phase plate for which the phase can be scanned on the MHz *** or top-hat phase patterns generate high-contrast compact excitation point-spread functions for MINFLUX localization in the x,y,and z-direction,respectively,which can be scanned across a fluorophore within a microsecond,switched within 60 microseconds and alternated among different excitation *** discuss how to compensate for non-optimal performance of the components and present a robust 3D and multi-color MINFLUX excitation module,which we envision as an integral component of a high-performance and cost-effective open-source MINFLUX.

关键词： excitation phase switched

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Bridging molecular photosensitizer and catalyst on carbon nanotubes toward enhanced selectivity and durability for CO_(2)photoreduction

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Journal of Environmental Sciences 2024年第6期140卷 157-164页

作者： Xiaofeng Cui Xueting Wang Lijun Zhao Jixin Wang Tingting Kong Yujie Xiong Anhui Engineering Research Center of Carbon Neutrality The Key Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Laboratory of Molecular-Based MaterialsCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China School of Chemistry and Chemical Engineering Anqing Normal UniversityAnqing 246011China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China

Homogenous molecular photocatalysts for CO_(2)reduction,especially metal complex-based photosensitizer-catalyst assemblages,have been attracting extensive research interests due to their efficiency and ***,their low durability and recyclability limit practical *** this work,we immobilized the catalysts of metal terpyridyl complexes and the photosensitizer of[Ru(bpy)3]Cl2onto the surface of carbon nanotubes through covalent bonds and electrostatic interactions,respectively,transforming the homogeneous system into a heterogeneous *** characterizations prove that these metal complexes are well dispersed on CNTs with a high loading(ca.12 wt.%).Photocatalytic measurements reveal that catalytic activity is remarkably enhanced when the molecular catalysts are anchored,which is three times higher than that of homogeneous molecular ***,when the photosensitizer of[Ru(bpy)3]Cl2is immobilized,the side reaction of hydrogen evolution is completely suppressed and the selectivity for CO production reaches 100%,with its durability also significantly *** work provides an effective pathway for constructing heterogeneous photocatalysts based on rational assembly of efficient molecular photosensitizers and catalysts.

关键词： durability selectivity catalyst

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