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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 ChemistryCentral China Normal UniversityWuhan 430079China Wuhan Institute of Photochemistry and Technology 7 North Bingang RoadWuhan 430083China Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province Gannan Normal UniversityGanzhou 341000China

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

LINEAR INSTABILITY OF TURBULENT BOUNDARY LAYER AS A MECHANISM FOR THE GENERATION OF LARGE SCALE COHERENT STRUCTURES

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Chinese Science Bulletin 1989年第20期34卷 1685-1688页

作者：吴雪松周恒 Department of Mechanics Tianjin University

I. BASIC IDEA Large eddies in the outer region of a turbulent boundary layer over a flat plate were found to have a mean streamwise extent of 2.5--3.0δ, where δ is the boundary layer thickness. Their convective velocity clusters around a value of 0.8U0, where U0 is the free stream velocity, and the period of their passage is roughly 3δ/U0.

关键词： coherent structure large eddy turbulent boundary layer

Unilateral spatial neglect,global processing deficit and prosopagnosia following right hemisphere stroke:a case report

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Chinese Medical Journal 2005年第21期118卷 1846-1848页

作者： LU xue-song YE Jing zhou Shu LU Bing-xun CHEN Xian-hong Department of Neurology Nanfang Hospital Southern Medical University Guangzhou 510515 China

Although unilateral spatial neglect, global processing deficit, or prosopagnosia followingbrain damage has been usually reported separately, to our knowledge, a report on a patient with the three mentioned syndromes has not been reported. We now present a case that developed unilateral spatial neglect, global processing deficit and prosopagnosia after right hemisphere stroke in September 2004.

关键词： attention prosopagnosia right hemisphere

关于网络计划“工期规定资源均衡”优化的几个问题

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铁道学报 2000年第4期22卷 117-130页

作者：邓雪松周继祖长沙铁道学院土木建筑学院湖南长沙410075

探讨了关于网络计划“工期规定资源均衡”优化的几个问题。对不同的优化目标、方法和具体算法进行了比较和分析 ,讨论了利用时差进行优化的实质。

关键词：网络计划 “工期规定资源均衡” 优化等价解

瓮安陡山沱组磷块岩中球状绿藻化石繁殖机制的发现(英文)

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微体古生物学报 2001年第4期18卷 373-378页

作者：薛耀松周传明唐天福中国科学院南京地质古生物研究所南京210008

贵州瓮安陡山沱组上段含磷地层中产有大量球状微化石 ,其中一些被鉴定为绿藻类分子。肖书海等认为这些被鉴定为绿藻分子的单细胞和多细胞球状化石中的 Megasphaera和 Parapandorina两属是动物卵和胚胎发育早期的化石。这一解释引起国际... 详细信息

贵州瓮安陡山沱组上段含磷地层中产有大量球状微化石 ,其中一些被鉴定为绿藻类分子。肖书海等认为这些被鉴定为绿藻分子的单细胞和多细胞球状化石中的 Megasphaera和 Parapandorina两属是动物卵和胚胎发育早期的化石。这一解释引起国际古生物学界的关注。然而 ,动物胚胎早期几次分裂非常迅速 ,可能在 2 4小时或更短的时间内即达到 6 4细胞分裂阶段 ,这使“动物胚胎”的解释蒙上难以捉摸的阴云。近年来 ,我们在实体标本的电镜扫描和岩石薄片研究中 ,观察到配子的存在和动孢子的释放 ,这是绿藻类繁殖的明显证据。在电子显微镜下 ,一个 8细胞球状化石 (Parapandorina raphospissa) (直径约 6 0 0 μm)的一个细胞中有若干特别的小球体 :外形陀螺状 ,直径和高均约为 2 0 μm,一端平而具螺旋状“脊”样装饰。我们认为这是被磷酸盐化而保存下来的配子。在岩石薄片中 ,见到表面光滑的球状化石的切面 (直径约 2 6 0 μm)中有一个圆形开口 (直径 10 0 μm) ,原生质凝缩后被磷酸盐化 ,与壁分离产生的孔洞中有连续的葡萄状磷质膜围绕 ,残余孔洞为白云石充填。另一个类似的切面(直径 2 40 μm)显示具有较厚的细胞壁 ,也有一个直径 10 0 μm的开口 ,成岩白云石的“塞子”中保存着一个直径约2 0 μm的磷酸盐化的小球 ,?

关键词：繁殖机制球状绿藻类陡山沱组贵州瓮安陡山沱组磷块岩化石

Study on the hydrogen absorption properties of a YGdTbDyHo rare-earth high-entropy alloy

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 127-135页

作者： Tongyue Li Ziliang Xie Wenjiao zhou Huan Tong Dawen Yang Anjia Zhang Yuan Wu Xiping song State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Whole Win(Beijing)Materials Sci.&Tech.Co. Ltd.Beijing 100083China

This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),*** indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed *** hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase *** alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period *** reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral *** results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.

关键词： rare-earth high-entropy alloy hydrogen absorption capacity pressure–composition–temperature curves kinetics

Recombinant chitinase-3-like protein 1 alleviates learning and memory impairments via M2 microglia polarization in postoperative cognitive dysfunction mice

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Neural Regeneration Research 2025年第9期20卷 2727-2736页

作者： Yujia Liu xue Han Yan Su Yiming zhou Minhui Xu Jiyan Xu Zhengliang Ma Xiaoping Gu Tianjiao Xia Department of Anesthesiology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsu ProvinceChina Medical School Nanjing UniversityNanjingJiangsu ProvinceChina Jiangsu Key Laboratory of Molecular Medicine Nanjing UniversityNanjingJiangsu ProvinceChina State Key Laboratory of Pharmaceutical Biotechnology Nanjing UniversityNanjingJiangsu ProvinceChina Department of Anesthesiology Zhongshan HospitalFudan UniversityShanghaiChina

Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of *** date,there are no viable treatment options for postoperative cognitive *** identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future *** identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial *** dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub ***,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re *** were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning *** addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western *** with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expr

关键词： Chil1 hippocampus learning and memory M2 microglia neuroinflammation postoperative cognitive dysfunction(POCD) recombinant CHI3L1

上尿路尿路上皮癌术前预后相关因素分析及初步风险分层模型构建

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北京大学学报（医学版） 2016年第6期48卷 1032-1037页

作者：邢云超熊耕砚方东张争蔡林张雷何志嵩李学松周利群北京大学第一医院泌尿外科北京大学泌尿外科研究所国家泌尿、男性生殖系肿瘤研究中心北京100034

目的:分析上尿路尿路上皮癌(upper tract urothelial carcinoma,UTUC)患者的术前预后因子,并构建适合中国患者的术前风险评估模型。方法:收集北京大学第一医院2003年至2013年的686例UTUC患者的临床和随访资料进行回顾性分析。结果:686... 详细信息

目的:分析上尿路尿路上皮癌(upper tract urothelial carcinoma,UTUC)患者的术前预后因子,并构建适合中国患者的术前风险评估模型。方法:收集北京大学第一医院2003年至2013年的686例UTUC患者的临床和随访资料进行回顾性分析。结果:686例患者中,男性303例(44.2%),女性383例(55.8%),术后高分期(T3和T4)肿瘤203例(29.6%),高分级(G3)肿瘤300例(43.7%),淋巴结转移(N1)54例(7.9%),其中,肾盂肿瘤、肿瘤长径大于5 cm、肾小球滤过率(estimated glomerular filtration rate,e GFR)≥30 m L/min和男性与术后肿瘤高分期相关;输尿管肿瘤、肿瘤长径大于5 cm、没有吸烟史与术后肿瘤高分级相关;肾盂肿瘤、肿瘤长径大于5 cm和术前贫血与术后淋巴结转移相关。患者的平均随访时间65个月,其间有208例(30.3%)患者死于肿瘤,210例(30.6%)患者出现了膀胱复发,其中肿瘤长径大于5 cm(P=0.001)、伴随同侧肾积水(P=0.041)和术前贫血(P=0.001)是患者术后肿瘤特异性死亡的独立危险因子,输尿管肿瘤(P=0.04)、多发肿瘤(P=0.005)和术前血肌酐含量大于133μmol/L(P=0.036)是患者术后膀胱复发的独立危险因素。结论:在UTUC患者常见的术前临床参数中,肿瘤长径大于5 cm、伴随同侧肾积水和术前贫血与术后肿瘤特异性生存呈独立相关,输尿管肿瘤、多发肿瘤和术前血肌酐大于133μmol/L与术后膀胱复发呈独立相关。基于这些术前预后因素构建的中国患者术前风险分层系统,可以帮助临床医生在术前就对患者进行初步的风险评估,并指导后续的临床治疗。

关键词：尿道上皮癌,移行细胞肿瘤复发,局部预后危险因素

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FSAE赛车转向梯形结构参数分析与优化

装备制造技术 2018年第7期 73-75,87页

作者：宋学前周岳斌黄成湖北文理学院机械工程学院湖北襄阳441053

为了优化转向梯形结构设计,建立了断开式转向梯形结构数学模型。考虑到转向过程中侧偏力对轮胎转角的影响,通过角位移传感器采集数据,对理想阿克曼转向轮转角进行矫正。利用MATLAB软件绘制了理论和矫正后的内外转向轮转角关系曲线,并根... 详细信息

为了优化转向梯形结构设计,建立了断开式转向梯形结构数学模型。考虑到转向过程中侧偏力对轮胎转角的影响,通过角位移传感器采集数据,对理想阿克曼转向轮转角进行矫正。利用MATLAB软件绘制了理论和矫正后的内外转向轮转角关系曲线,并根据内外转向轮转角关系曲线和阿克曼率优化了转向梯形结构设计,满足了赛车转向性能要求。

关键词：转向梯形数学模型分析矫正设计优化