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Nickel-Catalyzed Cross-Electrophile Vinyl–Vinyl Coupling:An Approach to Structurally Versatile Dienylboronates

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CCS Chemistry 2022年第3期4卷 864-871页

作者： Guang-Li Xu Chun-Yan liu Xiaobo Pang xue-yuan liu Xing-Zhong Shu State Key Laboratory of Applied Organic Chemistry(SKLAOC) College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000

Cross C–C bond formation of two vinyl electrophiles is a long-standing challenge in synthetic ***,we report a nickel-catalyzed reductive vinyl–vinyl coupling between vinyl triflates and boron-substituted vinyl *** new protocol offers facile access to dienylboronates with high structural complexity and molecular *** reaction proceeds with a broad substrate scope under very mild *** synthetic utility of the method is highlighted by its gram-scale reaction,modification of complex molecules,and diverse transformation of the products.

关键词： nickel boron dienes cross-coupling reductive coupling

Palladium-Catalyzed One-Step Synthesis of Stereodefined Difunctionalized Glycals

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CCS Chemistry 2023年第3期5卷 741-749页

作者： Xiao-Ping Gong Yuke Li Hong-Chao liu Zhe Zhang Zhi-Jie Niu Ya-Nan Ding Yang An Xi Chen Yan-Chong Huang Rui-Qiang Jiao xue-yuan liu Yong-Min Liang State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000 Department of Chemistry Centre for Scientific Modeling and ComputationChinese University of Hong KongShatinHong Kong 999077

Efficiently modifying glycals by directly introducing functional groups into their double bonds is a longstanding ***,the strategy of introducing two different functional groups into 1-iodoglycals to obtain modified glycals in one step through palladium catalysis was reported for the first time,and the modified glycals contained stereodefined tetrasubstituted *** this method,various difunctionalized glycals that were difficult to form by other routes were synthesized in moderate to good *** experiments and density functional theory calculations show that the palladium catalyst played dual roles in this transformation,namely,inducing nucleophilic substitution and catalyzing Suzuki *** reaction intermediate was isolated and confirmed by X-ray crystallographic ***,the gram-scale synthesis and facile deprotection of the target compound enhances the practicality of this strategy.

关键词： palladium catalysis glycals tetrasubstitute olefins difunctionalization stereodefined threecomponent

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手性降冰片烯衍生物的制备及应用

化学进展 2017年第6期29卷 605-616页

作者：曹堃袁贝刘学吴敏芳姚臻浙江大学化学工程与生物工程学院化学工程联合国家重点实验室杭州310027

手性降冰片烯类衍生物是C5主馏分之一的(双)环戊二烯中一类重要的高附加值衍生产品,主要由环戊二烯和非对称的亲双烯体通过Diels-Alder反应制得。本文从合成手性降冰片烯衍生物的机理出发,重点介绍了在有/无催化剂条件下制备手性降冰片... 详细信息

手性降冰片烯类衍生物是C5主馏分之一的(双)环戊二烯中一类重要的高附加值衍生产品,主要由环戊二烯和非对称的亲双烯体通过Diels-Alder反应制得。本文从合成手性降冰片烯衍生物的机理出发,重点介绍了在有/无催化剂条件下制备手性降冰片烯酯类、醛类、酮类和酰基口恶唑烷酮类衍生物时的收率和立体选择性等。由手性二醇、二酚或口恶唑啉与配位较强的铝、硼、铜、钛或镧系金属络合物等配位而成的手性催化剂有利于提高手性降冰片烯衍生物合成速度及其立体选择性。同时,本文针对近年来手性降冰片烯衍生物在光致变色的光学材料和阴离子、阳离子及复合离子交换膜领域中的应用进行了简要概述。最后,对其研究方向和应用前景进行了展望。

关键词：手性降冰片烯衍生物环戊二烯亲双烯体狄尔斯-阿尔德反应

Stochastic Augmented-Based Dual-Teaching for Semi-Supervised Medical Image Segmentation

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Computers, Materials & Continua 2025年第1期82卷 543-560页

作者： Hengyang liu Yang yuan Pengcheng Ren Chengyun Song Fen Luo School of Computer Science and Engineering Chongqing University of TechnologyChongqing400054China College of Artificial Intelligence Chongqing Technology and Business UniversityChongqing400067China

Existing semi-supervisedmedical image segmentation algorithms use copy-paste data augmentation to correct the labeled-unlabeled data distribution ***,current copy-paste methods have three limitations:(1)training the model solely with copy-paste mixed pictures from labeled and unlabeled input loses a lot of labeled information;(2)low-quality pseudo-labels can cause confirmation bias in pseudo-supervised learning on unlabeled data;(3)the segmentation performance in low-contrast and local regions is less than *** design a Stochastic Augmentation-Based Dual-Teaching Auxiliary Training Strategy(SADT),which enhances feature diversity and learns high-quality features to overcome these *** be more precise,SADT trains the Student Network by using pseudo-label-based training from Teacher Network 1 and supervised learning with labeled data,which prevents the loss of rare labeled *** introduce a bi-directional copy-pastemask with progressive high-entropy filtering to reduce data distribution disparities and mitigate confirmation bias in *** the mixed images,Deep-Shallow Spatial Contrastive Learning(DSSCL)is proposed in the feature spaces of Teacher Network 2 and the Student Network to improve the segmentation capabilities in low-contrast and local *** this procedure,the features retrieved by the Student Network are subjected to a random feature perturbation *** two openly available datasets,extensive trials show that our proposed SADT performs much better than the state-ofthe-art semi-supervised medical segmentation *** only 10%of the labeled data for training,SADT was able to acquire a Dice score of 90.10%on the ACDC(Automatic Cardiac Diagnosis Challenge)dataset.

关键词： Semi-supervised medical image segmentation contrastive learning stochastic augmented

The complex roles of m^(6)A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

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Neural Regeneration Research 2025年第6期20卷 1582-1598页

作者： Yanxi Li Jing xue Yuejia Ma Ke Ye xue Zhao Fangliang Ge Feifei Zheng Lulu liu Xu Gao Dayong Wang Qing Xia Department of Biochemistry and Molecular Biology College of Basic Medical SciencesHarbin Medical UniversityHarbinHeilongjiang ProvinceChina College of Basic Medical Sciences Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Basic Medical Institute Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Key Laboratory of Heilongjiang Province for Genetically Modified Animals Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Translational Medicine Research and Cooperation Center of Northern China Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

N6-methyladenosine(m^(6)A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m^(6)A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m^(6)A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m^(6)A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m^(6)A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m^(6)A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m^(6)A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m^(6)A's role in neurodegenerative processes. The roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be a

关键词： Alzheimer's disease cell self-renewal central nervous system memory microglia nerve regeneration neurodegenerative diseases neurogenesis RNA methylation

Influence of introducing Zr,Ti,Nb and Ce elements on externally solidified crystals and mechanical properties of high-pressure die-casting Al–Si alloy

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 147-153页

作者： Junjie Li Wenbo Yu Zhenyu Sun Weichen Zheng Liangwei Zhang Yanling xue Wenning liu Shoumei Xiong Center of Materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Traffic&Transportation Engineering Central South UniversityChangsha 410075China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile *** can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated ***,the development of non-heat treatment Al alloys is becoming the hot *** addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of *** achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and *** influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic *** results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased ***,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical *** introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

关键词： aluminium alloy high-pressure die-casting externally solidified crystals non-heat treatment

Comparative proteomic analysis of plasma exosomes reveals the functional contribution of N-acetyl-alpha-glucosaminidase to Parkinson’s disease

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Neural Regeneration Research 2025年第10期20卷 2998-3012页

作者： yuan Zhao Yidan Zhang Xin liu Jian Zhang Ya Gao Shuyue Li Cui Chang Xiang liu Guofeng Yang Department of Geriatrics Second Hospital of Hebei Medical UniversityShijiazhuangHebei ProvinceChina Department of Neurosurgery The Second Hospital of Hebei Medical UniversityShijiazhuangHebei ProvinceChina

Parkinson’s disease is the second most common progressive neurodegenerative disorder,and few reliable biomarkers are available to track disease *** proteins,DNA,mRNA,and lipids carried by exosomes reflect intracellular changes,and thus can serve as biomarkers for a variety of *** this study,we investigated alterations in the protein content of plasma exosomes derived from patients with Parkinson’s disease and the potential therapeutic roles of these proteins in Parkinson’s *** a tandem mass tag-based quantitative proteomics approach,we characterized the proteomes of plasma exosomes derived from individual patients,identified exosomal protein signatures specific to patients with Parkinson’s disease,and identified N-acetyl-alpha-glucosaminidase as a differentially expressed protein.N-acetyl-alpha-glucosaminidase expression levels in exosomes from the plasma of patients and healthy controls were validated by enzyme-linked immunosorbent assay and western *** results demonstrated that the exosomal N-acetyl-alpha-glucosaminidase concentration was not only lower in Parkinson’s disease,but also decreased with increasing Hoehn-Yahr stage,suggesting that N-acetyl-alpha-glucosaminidase could be used to rapidly evaluate Parkinson’s disease ***,western blot and immunohistochemistry analysis showed that N-acetyl-alpha-glucosaminidase levels were markedly reduced both in cells treated with 1-methyl-4-phenylpyridinium and cells overexpressingα-synuclein compared with control ***,N-acetyl-alpha-glucosaminidase overexpression significantly increased cell viability and inhibitedα-synuclein expression in 1-methyl-4-phenylpyridinium-treated *** together,our findings demonstrate for the first time that exosomal N-acetyl-alpha-glucosaminidase may serve as a biomarker for Parkinson’s disease diagnosis,and that N-acetyl-alpha-glucosaminidase may reduceα-synuclein expression and 1-methyl-4-phenylpyridinium-induced n

关键词： biomarker diagnosis exosomes N-acetyl-alpha-glucosaminidase Parkinson’s disease proteomic α-synuclein

Advances in the Development of Gradient Scaffolds Made of Nano‑Micromaterials for Musculoskeletal Tissue Regeneration

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Nano-Micro Letters 2025年第3期17卷 455-500页

作者： Lei Fang Xiaoqi Lin Ruian Xu Lu liu Yu Zhang Feng Tian Jiao Jiao Li Jiajia xue Beijing Laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China School of Biomedical Engineering Faculty of Engineering and ITUniversity of Technology SydneySydneyNSW 2007Australia

The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered *** has led to growing interest in the development of gradient bone scaffolds with hierarchical structures mimicking the extracellular matrix of native tissues to achieve improved therapeutic *** on the anatomical characteristics of bone and interfacial tissues,this review provides a summary of current strategies used to design and fabricate biomimetic gradient scaffolds for repairing musculoskeletal tissues,specifically focusing on methods used to construct compositional and structural gradients within the *** latest applications of gradient scaffolds for the regeneration of bone,osteochondral,and tendon-to-bone interfaces are ***,the current progress of testing gradient scaffolds in physiologically relevant animal models of skeletal repair is discussed,as well as the challenges and prospects of moving these scaffolds into clinical application for treating musculoskeletal injuries.

关键词： Gradient scaffolds Musculoskeletal tissues Advanced manufacturing Biomaterials Tissue regeneration

Construction of 3D porous Cu_(1.81)S/nitrogen-doped carbon frameworks for ultrafast and long-cycle life sodium-ion storage

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 191-200页

作者： Chen Chen Hongyu xue Qilin Hu Mengfan Wang Pan Shang Ziyan liu Tao Peng Deyang Zhang Yongsong Luo Key Laboratory of Microelectronics and Energy of Henan Province Henan Joint International Research Laboratory of New Energy Storage TechnologyCollege of Physics and Electronic EngineeringXinyang Normal UniversityXinyang 464000China School of Physics and Electronic Engineering Nanyang Normal UniversityNanyang 473061China

Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific ***,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs ***,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for ***,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 *** work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode.

关键词： copper sulfide nanoparticles porous carbon framework fast charging long-cycle performance sodium-ion full batteries