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Asymmetric radical allylation of β-keto esters with vinyl cyclopropanes by dual photoredox/nickel catalysis

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Science China Chemistry 2024年第11期67卷 3807-3816页

作者： Wen-Yuan Qu xue-Song Zhou Wen-Jing Xiao Jia-rong Chen Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction Ministry of EducationCollege of Chemistry Central China Normal University Wuhan Institute of Photochemistry and Technology Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province Gannan Normal University

Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.

关键词： asymmetric allylation photoredox catalysis radical addition nickel catalysis β-keto esters vinyl cyclopropanes

变截面波形钢腹板PC组合连续箱梁横向受力性能研究

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桥梁建设 2023年第2期53卷 90-97页

作者：赵品荣学亮王涛卜建清省部共建交通工程结构力学行为与系统安全国家重点实验室河北石家庄050043 石家庄铁道大学土木工程学院河北石家庄050043 道路与铁道工程安全保障省部共建教育部重点实验室河北石家庄050043

为研究变截面波形钢腹板PC组合连续箱梁的横向内力分布规律及有效分布宽度,以某连续梁桥为背景,设计、制作一片三跨变截面波形钢腹板PC组合连续箱梁的缩尺模型,通过试验与有限元模拟相结合的方法进行试验梁横向内力研究。按分级加载方... 详细信息

为研究变截面波形钢腹板PC组合连续箱梁的横向内力分布规律及有效分布宽度,以某连续梁桥为背景,设计、制作一片三跨变截面波形钢腹板PC组合连续箱梁的缩尺模型,通过试验与有限元模拟相结合的方法进行试验梁横向内力研究。按分级加载方式分别在试验梁中跨跨中与边跨跨中进行单点与双点加载,并采用Abaqus软件建立试验梁有限元模型,分析各工况下跨中截面的横向内力,以及中支点、横隔板对横向内力分布的影响;最后推导有效分布宽度计算公式,并与现行桥规值对比。结果表明:沿中线单点加载时,试验梁的横向应力由中腹板位置的顶板向两侧逐渐递减,偏载时两侧边腹板的横向应力差值较大,偏载工况下畸变与横向翘曲现象较明显,可采用增大腹板线刚度或增加横隔板厚度等措施进行改善;中支点对横向应力的分布具有较大的影响,工程应用应考虑中支点的影响;设置横隔板对抵抗跨中横向负弯矩具有较好的效果,横隔板处顶板横向应力明显减小;与有效分布宽度试验值相比,按桥规计算得到的有效分布宽度值较为保守,建议对现行桥规值进行适当修正。

关键词：组合梁箱形梁波形钢腹板横向应力有效分布宽度模型试验有限元法

Gut microbiota-bile acid crosstalk and metabolic fatty liver in spotted seabass(Lateolabrax maculatus): The role of a cholesterol, taurine and glycine supplement

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Animal Nutrition 2024年第2期17卷 87-99页

作者： Tingting Song Xiaofang liang Hao Wang Min xue Jie Wang National Aquafeed Safety Assessment Center Institute of Feed Research Chinese Academy of Agricultural Sciences

The prevalent practice of substituting fishmeal with plant protein frequently leads to disturbances in bile acid metabolism, subsequently increasing the incidence of metabolic liver diseases. Bile acid nutrients such as cholesterol, taurine and glycine have been shown to enhance bile acid synthesis and confer beneficial effects on growth. Therefore, this study aimed to investigate the effects of cholesterol-taurineglycine(Ch-Tau-Gly) supplement on bile acid metabolism and liver health in spotted seabass(Lateolabrax maculatus) fed a plant-based diet. Two isonitrogenous and isolipidic diets were formulated:(1) plant protein-based diet(PP);(2) PP supplemented 0.5% cholesterol, 0.5% taurine and 1.3% glycine(CTG). Each experimental diet was randomly fed to quadruplicate groups of 30 feed-trained spotted seabass in each tank. The results revealed that supplementing plant-based diet with Ch-Tau-Gly supplement led to an increase in carcass ratio(meat yield) in spotted seabass(P < 0.05), indirectly contributing positively to their growth. The dietary supplement effectively suppressed endogenous cholesterol synthesis in the liver, promoted the expression of bile acid synthesis enzyme synthesis, and simultaneously the expression of intestinal fxr and its downstream genes, including hnf4a and shp(P < 0.05). The reduction in Lactobacillus＿salivarius and bile salt hydrolase(BSH) were observed in CTG group with concurrently increased conjugated chenodeoxycholic acid(CDCA) bile acids(P < 0.05), suggesting the enhancement of the hydrophilicity of the bile acid pool. In CTG group, fatty liver was alleviated with a corresponding increase in lipid metabolism, characterized by a downregulation of genes associated with lipogenesis and lipid droplet deposition, along with an upregulation of genes related to lipolysis. Our study underscored the ability of Ch-Tau-Gly supplement to influence the gut microbiota, leading to an increase in the levels of conjugated CDCA(P < 0.05) in the bile aci

关键词： Cholesterol-taurine-glycine supplement Plant-based diets Fatty liver Gut microbiota–bile acid crosstalk Lipid metabolism

Engineering of geometrical configurations in dual-atom catalysts for electrocatalytic applications

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Journal of Energy Chemistry 2024年第7期94卷 273-287页

作者： Tao Zhang Yifan Liu liang xue Jingwen Sun Pan Xiong Junwu Zhu Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education School of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing210094JiangsuChina

Geometrical configurations play a crucial role in dual-atom catalysts(DACs)for electrocatalytic *** progress has been made to design DACs electrocatalysts with various geometri-cal configurations,but in-depth understanding the relationship between geometrical configurations and metal-metal interaction mechanisms for designing targeted DACs is still *** this review,the recent progress in engineering of geometrical configurations of DACs is systematically *** on the polarity of geometrical configuration,DACs can be classified into two different types that are homonuclear and heteronuclear ***,with regard to the geometrical configurations of the active sites,homonuclear DACs are identified into adjacent and bridged configurations,and heteronuclear DACs can be classified into adjacent,bridged,and separated ***,metal-metal interactions in DACs with different geometrical configurations are ***,the applications of DACs in different electrocatalytic reactions are discussed,including the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),hydrogen evolution reaction(HER),and other ***,the future challenges and perspectives for advancements in DACs are *** review aims to provide inspiration for the design of highly effcient DACs towards energy relatedapplications.

关键词： Dual-atom catalysts Geometrical configurations Homonuclear Heteronuclear Electrocatalysis

Alzheimer’s disease early diagnostic and staging biomarkers revealed by large-scale cerebrospinal fluid and serum proteomic profiling

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The Innovation 2024年第1期5卷 118-126页

作者： Qing-Qing Tao xue Cai Yan-Yan xue Weigang Ge liang Yue Xiao-Yan Li rong-rong Lin Guo-Ping Peng Wenhao Jiang Sainan Li Kun-Mu Zheng Bin Jiang Jian-Ping Jia Tiannan Guo Zhi-Ying Wu Department of Neurology and Research Center of Neurology in the Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of MedicineHangzhou 310009China liangzhu Laboratory Zhejiang UniversityHangzhou 311100China Westlake Laboratory of Life Sciences and Biomedicine Key Laboratory of Structural Biology of Zhejiang ProvinceSchool of Life SciencesWestlake UniversityHangzhou 310024China Institute of Basic Medical Sciences Westlake Institute for Advanced StudyHangzho 310024China Department of Neurology First Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Department of Neurology First Affiliated HospitalSchool of MedicineXiamen UniversityXiamen 361009China Innovation Center for Neurological Disorders and Department of Neurology Xuanwu HospitalCapital Medical UniversityNational Clinical Research Center for Geriatric DiseasesBeijing 100053China MOE Frontier Science Center for Brain Science and Brain-machine Integration School of Brain Science and Brain MedicineZhejiang UniversityHangzhou 310058China CAS Center for Excellence in Brain Science and Intelligence Technology Shanghai 200031China

Amyloid-b,tau pathology,and biomarkers of neurodegeneration make up the core diagnostic biomarkers of Alzheimer disease(AD).However,these proteins represent only a fraction of the complex biological processes underlying AD,and individuals with other brain diseases in which AD pathology is a comorbidity also test positive for these diagnostic *** ADspecific early diagnostic and disease staging biomarkers are *** this study,we performed tandem mass tag proteomic analysis of paired cerebrospinal fluid(CSF)and serum samples in a discovery cohort comprising 98 *** biomarkers were validated by parallel reaction monitoring–based targeted proteomic assays in an independent multicenter cohort comprising 288 *** quantified 3,238 CSF and 1,702 serum proteins in the discovery cohort,identifying 171 and 860 CSF proteins and 37 and 323 serum proteins as potential early diagnostic and staging biomarkers,*** the validation cohort,58 and 21 CSF proteins,as well as 12 and 18 serum proteins,were verified as early diagnostic and staging biomarkers,*** 19-protein CSF and an 8-protein serum biomarker panels were built by machine learning to accurately classify mild cognitive impairment(MCI)due to AD from normal cognition with areas under the curve of 0.984 and 0.881,*** 19-protein CSF biomarker panel also effectively discriminated patients with MCI due to AD from patients with other neurodegenerative ***,we identified 21 CSF and 18 serum stage-associated proteins re-flecting AD *** findings provide a foundation for developing bloodbased tests for AD screening and staging in clinical practice.

关键词： cerebrospinal Alzheimer fluid

Cracking on a nickel-based superalloy fabricated by direct energy deposition

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China Foundry 2024年第4期21卷 311-318页

作者： xue Zhang Ya-hang Mu liang Ma Jing-jing liang Yi-zhou Zhou Xiao-feng Sun Jin-guo Li School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based *** is essential to investigate the location of cracks and their forming *** study extensively examines the impact of solidification process,microstructural evolution,and stress concentration on crack initiation during direct energy deposition(DED).The results emphasize that the crack formation is significantly related to large-angle grain boundaries,rapid cooling *** caused by large-angle grain boundaries and a fast-cooling rate predominantly appear near the edge of the deposited *** cracks are more likely to form near the top of the deposited sample,due to the presence ofγ/γ'*** secondary dendritic arm and the carbides in the interdendritic regions can obstruct liquid flow during the final stage of solidification,which results in the formation of solidification cracks and *** work paves the way to avoid cracks in nickel-based superalloys fabricated by DED,thereby enhancing the performance of superalloys.

关键词： location cracks direct energy deposition nickel-based superalloys

Advancing brain-inspired computing with hybrid neural networks

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National Science Review 2024年第5期11卷 56-71页

作者： Faqiang Liu Hao Zheng Songchen Ma Weihao Zhang xue Liu Yansong Chua Luping Shi rong Zhao Center for Brain-Inspired Computing Research Optical Memory National Engineering Research CenterTsinghua University-China Electronics Technology HIK Group Co.Joint Research Center for Brain-inspired ComputingIDGMc Govern Institute for Brain Research Department of Precision Instrument Tsinghua University Neuromorphic Computing Laboratory China Nanhu Academy of Electronics and Information Technology

Brain-inspired computing, drawing inspiration from the fundamental structure and information-processing mechanisms of the human brain, has gained significant momentum in recent years. It has emerged as a research paradigm centered on brain–computer dual-driven and multi-network integration. One noteworthy instance of this paradigm is the hybrid neural network(HNN), which integrates computer-science-oriented artificial neural networks(ANNs) with neuroscience-oriented spiking neural networks(SNNs). HNNs exhibit distinct advantages in various intelligent tasks, including perception, cognition and learning. This paper presents a comprehensive review of HNNs with an emphasis on their origin, concepts, biological perspective, construction framework and supporting systems. Furthermore, insights and suggestions for potential research directions are provided aiming to propel the advancement of the HNN paradigm.

关键词： brain-inspired computing hybrid neural network dual-brain driven multi-network integration neuromorphic system

Effects of proton pump inhibitors on inflammatory bowel disease:An updated review

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World Journal of Gastroenterology 2024年第21期30卷 2751-2762页

作者： Yu liang Zhen Meng xue-Li Ding Man Jiang Department of Pharmacy The Affiliated Hospital of Qingdao UniversityQingdao 266003Shandong ProvinceChina Department of Intervention The Affiliated Hospital of Qingdao UniversityQingdao 266003Shandong ProvinceChina Department of Gastroenterology The Affiliated Hospital of Qingdao UniversityQingdao 266003Shandong ProvinceChina

Inflammatory bowel disease(IBD)is believed to be caused by various factors,including abnormalities in disease susceptibility genes,environmental factors,immune factors,and intestinal *** pump inhibitors(PPIs)are the primary drugs used to treat acid-related *** are also commonly prescribed to patients with *** studies have suggested a potential association between the use of certain medications,such as PPIs,and the occurrence and progression of *** this review,we summarize the potential impact of PPIs on IBD and analyze the underlying *** findings may provide insights for conducting further investigations into the effects of PPIs on IBD and serve as an important reminder for physicians to exercise caution when prescribing PPIs to patients with IBD.

关键词： Drug safety Proton pump inhibitor Inflammatory bowel disease Ulcerative colitis Crohn’s disease

Effects of alcohol on digestion,absorption and metabolism of sea cucumber saponins in healthy mice

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Food Science and Human Wellness 2024年第1期13卷 137-145页

作者： Wenxian Dang rong Li Jinyue Yang Changhu xue Qingrong Huang Yuming Wang Tiantian Zhang College of Food Science and Engineering Ocean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Department of Food Science Rutgers State University New BrunswickNJ 08901USA

Sea cucumber saponins have attracted more attention in recent years due to biological *** is a popular practice to soak sea cucumber in Baijiu at home and being applied to industrial manufacturing in ***,knowledge of the effect of alcohol on the absorption and metabolism of sea cucumber saponins is *** effects of alcohol on digestion,absorption and metabolism of sea cucumber saponins in BALB/c mice were investigated after gavage and tail intravenous *** results showed that the content of saponins in serum and liver was significantly higher under the influence of alcohol than that in the control group after oral *** promoted the absorption of sea cucumber saponins prototype as well as inhibited the process of saponins being transformed into deglycositic metabolites in the small ***,sea cucumber saponins remained in circulation for a long time and alcohol slowed down the clearance of sea cucumber saponins under the influence of alcohol after intravenous *** confirmed the feasibility of marinating sea cucumber in Baijiu to improve the efficacy of saponins and provides an important theoretical basis for the utilization of sea cucumber and the development of sea cucumber liquor.

关键词： Holothurin A Echinoside A Alcohol Absorption Metabolism