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Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

Science China Chemistry 2025年

作者： Shuai zhang Pei-Zhi Liu Yan-bo Li Qi zhang Jun-Zhao Xiao Yi-Fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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荞麦花叶黄酮对2型糖尿病大鼠肝损伤及IRS-2、PI3K、NF-κB表达的影响

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中国药理学通报 2013年第11期29卷 1582-1586页

作者：韩淑英姜妍王志路王建行张博男韩婷闫文娜河北联合大学药理学教研室河北联合大学冀唐学院教学管理部唐山师范学院教育学院教务处河北联合大学冀唐学院医学实验中心河北唐山063000

目的观察荞麦花叶黄酮(FBFL)对2型糖尿病大鼠肝损伤和IRS-2、PI3K及NF-κB表达的影响,并探讨其可能机制。方法用高脂饲料和链脲佐菌素建立大鼠2型糖尿病模型,以FBFL为干预因素,动态观察随机血糖(PBG)、空腹血糖(FBG)、空腹血胰岛素(FINS... 详细信息

目的观察荞麦花叶黄酮(FBFL)对2型糖尿病大鼠肝损伤和IRS-2、PI3K及NF-κB表达的影响,并探讨其可能机制。方法用高脂饲料和链脲佐菌素建立大鼠2型糖尿病模型,以FBFL为干预因素,动态观察随机血糖(PBG)、空腹血糖(FBG)、空腹血胰岛素(FINS)、血ALT、AST,光镜和电镜观察肝脏病理改变,免疫组化和Western blot检测肝IRS-2和PI3K蛋白表达。ELISA法检测肝组织NF-κB含量。结果与正常组比较,模型组大鼠血中PBG、FBG、FINS、HOMA-IR(胰岛素抵抗指数)、ALT、AST均明显升高(P<0.05,P<0.01),肝病理损伤明显,同时IRS-2、PI3K蛋白表达减少,NF-κB含量增加;FBFL治疗组能明显改善上述指标的变化,增加胰岛素敏感性,使肝组织损伤减轻和上调IRS-2、PI3K蛋白表达及减少NF-κB含量,且FBFL高剂量作用更明显。结论 FBFL对糖尿病肝损伤有抑制作用,其机制可能是通过降低血糖、改善胰岛素抵抗,上调IRS-2、PI3K蛋白表达及下调NF-κB蛋白表达等多途径实现的。

关键词：荞麦花叶黄酮 2型糖尿病肝损伤 IRS-2 PI3K NF-κB 胰岛素抵抗指数

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可调式汽轮发电机定子线棒端部成形设备研制

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模具工业 2017年第9期43卷 38-41页

作者：李霖张波陈楠李太波于代军张大龙山东齐鲁电机制造有限公司山东济南250100

为了解决现有成形设备柔性差的缺陷,开发了可调式汽轮发电机定子线棒端部成形设备,组合可调的结构使该设备可用于多种规格线棒的弯曲成形,采用机械、液压及电气一体化的操作系统,提高了成形设备的柔性,缩短了产品的制造周期,降低了生产... 详细信息

为了解决现有成形设备柔性差的缺陷,开发了可调式汽轮发电机定子线棒端部成形设备,组合可调的结构使该设备可用于多种规格线棒的弯曲成形,采用机械、液压及电气一体化的操作系统,提高了成形设备的柔性,缩短了产品的制造周期,降低了生产成本。

关键词：定子线棒成形设备渐开线锥体反弹变形

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Dendrobium officinale extract exerts antioxidant effects against skin photoaging through MMP9-TNF pathway

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Traditional Medicine Research 2025年第3期10卷 32-41页

作者： Bei-Bei Dong Yun Wang Han Zhao Wu-Yan Guo bo zhang College of Pharmacy Nankai UniversityTianjin 300350China Hepatobiliary Pancreatic Center Xuzhou Central HospitalXuzhou 221009China Clinic for Kidney and Hypertensive Diseases Hanover Medical SchoolHanover 30625Germany Tianjin JiAnKang Bio&TCM-technology Development Co. Ltd.Tianjin 300457China Institute for TCM-X MOE Key Laboratory of BioinformaticsBioinformatics DivisionBNRistDepartment of AutomationTsinghua UniversityBeijing 100084China

Background:Skin photoaging is a physiological or pathological process caused by multiple *** anti-skin photoaging drugs is a hot topic in cosmetology research *** purpose of this study was to explore the therapeutic effect of Dendrobium officinale(***)on skin ***:The ingredients of *** were detected by UHPLC-Q-TOF/*** targets of *** were screened by Swiss Target Prediction ***,NCBI,and OMIM databases were utilized to find out the targets associated with skin *** targets of *** and skin photoaging were obtained by Venn *** ingredient-disease target network and protein-protein interaction network were constructed by using the STRING database and Cytoscape *** key compounds and hub genes were obtained by analyzing *** DAVID database was applied for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of the overlapping *** Vina software was used to simulate molecular docking and the results were visualized using ***,the skin photoaging models of cells and mice were established to validate the results predicted by network ***:In ***,a total of 59 compounds and 595 targets were detected,of which 59 proteins were intersectional with skin photoaging *** top 10 active ingredients(Dendrophenol,Herbacetin,Lyoniresinol,Trans-ferulaldehyde,Naringenin,and so on)and 8 hub genes(AKT1,TNF,VEGFA,MAPK3,CASP3,MMP9,CTNNB1,and EGFR)were *** the key active compounds could bind well with core protein targets(binding energybolic process,extracellular matrix organization,and apoptotic process,*** also found that *** could enhance the cell viability and activity of anti-oxidases,reduce reactive oxygen species and MMP9 levels,and stable mitoc

关键词： Dendrobium officinale skin photoaging matrix metalloproteinase anti-oxidative stress

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Sensitivity improvement by Vernier effect in microwave photonic filter based on F-P fiber ring

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Optoelectronics Letters 2025年

作者： LIN Rui zhang Ailing CHANG Pengxiang PAN Honggang WANG Minghe WANG bo Engineering Research Center of Optoelectronic Devices & Communication Technology， Ministry of Education， Tianjin Key Laboratory of Film Electronic and Communication Devices， School of Electrical and Electronic Engineering， Tianjin University of Technology

A high sensitivity fiber optic temperature sensor based on Vernier effect in microwave photonic filter based on two paralleled F-P (Fabry-Perot) fiber ring is proposed and experimentally verified. Sensitivity is improved through the Vernier effect， which is caused by two parallel F-P fiber rings with approximate lengths. Temperature interrogation is achieved by monitoring the notch frequency of the superimposed frequency response curve. The temperature sensitivity of -484.514kHz/℃ is achieved in experiment， which is 57 times of the sensor without Vernier effect. The improved sensitivity and simple structure make it have wide potential applications in temperature monitoring of power systems.

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Particle Swarm Optimization Algorithm for Feature Selection Inspired by Peak Ecosystem Dynamics

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Computers, Materials & Continua 2025年第2期82卷 2723-2751页

作者： Shaobo Deng Meiru Xie bo Wang Shuaikun zhang Sujie Guan Min Li School of Information Engineering Nanchang Institute of TechnologyNanchang330099China

In recent years, particle swarm optimization (PSO) has received widespread attention in feature selection due to its simplicity and potential for global search. However, in traditional PSO, particles primarily update based on two extreme values: personal best and global best, which limits the diversity of information. Ideally, particles should learn from multiple advantageous particles to enhance interactivity and optimization efficiency. Accordingly, this paper proposes a PSO that simulates the evolutionary dynamics of species survival in mountain peak ecology (PEPSO) for feature selection. Based on the pyramid topology, the algorithm simulates the features of mountain peak ecology in nature and the competitive-cooperative strategies among species. According to the principles of the algorithm, the population is first adaptively divided into many subgroups based on the fitness level of particles. Then, particles within each subgroup are divided into three different types based on their evolutionary levels, employing different adaptive inertia weight rules and dynamic learning mechanisms to define distinct learning modes. Consequently, all particles play their respective roles in promoting the global optimization performance of the algorithm, similar to different species in the ecological pattern of mountain peaks. Experimental validation of the PEPSO performance was conducted on 18 public datasets. The experimental results demonstrate that the PEPSO outperforms other PSO variant-based feature selection methods and mainstream feature selection methods based on intelligent optimization algorithms in terms of overall performance in global search capability, classification accuracy, and reduction of feature space dimensions. Wilcoxon signed-rank test also confirms the excellent performance of the PEPSO.

关键词： Machine learning feature selection evolutionary algorithm particle swarm optimization

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Graphene Size Dependent Hardness and Strengthening Mechanisms of Cu/Graphene Composites:A Molecular Dynamics Study

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稀有金属材料与工程 2025年第1期54卷 17-26页

作者： zhang Shuang Chang Guo Li Liang Li Xiang Peng Haoran Chen Kaiyun Yang nan Huo Wangtu Advanced Materials Research Center Northwest Institute for Nonferrous Metal ResearchXi'an 710016China United Technology Center Western Metal Materials Co.LtdXi'an 710201China

The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of ***,the effect of the graphene size/distribution on the mechanical properties and related strengthening mechanisms has not been fully ***,under the same volume fraction and distribution conditions of graphene,molecular dynamics simulations were used to investigate the effect of graphene sheet size on the hardness and deformation behavior of Cu/graphene composites under complex stress *** models of pure single crystalline Cu and graphene fully covered Cu matrix composite were constructed for *** results show that the strengthening effect changes with varying the graphene sheet *** the graphene dislocation blocking effect and the load-bearing effect,the deformation mechanisms change from stacking fault tetrahedron,dislocation bypassing and dislocation cutting to dislocation nucleation in turn with decreasing the graphene sheet *** hardness of Cu/graphene composite,with the graphene sheet not completely covering the metal matrix,can even be higher than that of the fully covered *** extra strengthening mechanisms of dislocation bypassing mechanism and the stacking fault tetrahedra pinning dislocation mechanism contribute to the increase in hardness.

关键词： Cu/graphene composites graphene size hardness strengthening mechanism molecular dynamics

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New scoring system for the evaluation obstructive degrees based on computed tomography for obstructive colorectal cancer

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World Journal of Gastrointestinal Oncology 2025年第3期17卷 122-132页

作者： Xin-Chang Shang-Guan Jun-Rong zhang Chao-nan Lin Shuai Chen Yong Wei Wen-Xuan Chen Lin Pan Li-Qin Huang Shao-Hua Zheng Xian-Qiang Chen Department of Emergency Surgery Fujian Medical University Union HospitalFuzhou 350001Fujian ProvinceChina College of Physics and Information Engineering Fuzhou UniversityFuzhou 350001Fujian ProvinceChina

BACKGROUND The degree of obstruction plays an important role in decision-making for obstructive colorectal cancer(OCRC).The existing assessment still relies on the colorectal obstruction scoring system(CROSS)which is based on a comprehensive analysis of patients’complaints and eating *** data collection relies on subjective descriptions and lacks objective ***,a scoring system for the evaluation of computed tomography-based obstructive degree(CTOD)is urgently required for *** To explore the relationship between CTOD and CROSS and to determine whether CTOD could affect the short-term and long-term *** Of 173 patients were *** was obtained using k-means,the ratio of proximal to distal obstruction,and the proportion of nonparenchymal areas at the site of *** was integrated with the CROSS to analyze the effect of emergency intervention on ***-term and long-term outcomes were compared between the *** CTOD severe obstruction(CTOD grade 3)was an independent risk factor[odds ratio(OR)=3.390,95%confidence interval(CI):1.340-8.570,P=0.010]via multivariate analysis of short-term outcomes,while CROSS grade was *** the CTOD-CROSS grade system,for the non-severe obstructive(CTOD 1-2 to CROSS 1-4)group,the complication rate of emergency interventions was significantly higher than that of non-emergency interventions(71.4%vs 41.8%,P=0.040).The postoperative pneumonia rate was higher in the emergency intervention group than in the non-severe obstructive group(35.7%vs 8.9%,P=0.020).However,CTOD grade was not an independent risk factor of overall survival and progression-free *** CTOD was useful in preoperative decision-making to avoid unnecessary emergency interventions and complications.

关键词： Obstructive colorectal cancer Scoring system Computed tomography-based obstructive degree Colorectal obstruction scoring system Emergency intervention

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渭河流域地下水氮污染的来源示踪及其迁移转化过程识别

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环境科学学报 2025年第1期45卷 272-282页

作者：杨楠张妍孙豪王超西北大学城市与环境学院西安710127 西安理工大学西北旱区生态水利国家重点实验室西安710048

地下水氮污染与人类健康息息相关,对氮污染来源的划分是有效控制地下水污染的关键.本研究采集了渭河流域地下水样品,结合水化学方法和环境稳定同位素技术,对冬夏两季地下水中氮污染的时空分布特征、迁移转化过程及来源进行了研究,并结合... 详细信息

地下水氮污染与人类健康息息相关,对氮污染来源的划分是有效控制地下水污染的关键.本研究采集了渭河流域地下水样品,结合水化学方法和环境稳定同位素技术,对冬夏两季地下水中氮污染的时空分布特征、迁移转化过程及来源进行了研究,并结合SIAR同位素混合模型定量分析了不同来源氮对地下水硝酸盐氮的贡献率.结果表明,硝酸盐氮是渭河流域地下水氮污染的主要形式.夏季和冬季硝酸盐氮与氨氮浓度无显著性差异(p>0.05),而亚硝酸盐氮浓度在冬季显著大于夏季(p<0.01).硝酸盐氮浓度在空间上无显著性差异,亚硝酸盐氮浓度下游大于上、中游(p<0.01),氨氮浓度表现为中游大于上游和下游(p<0.01).冬季宝鸡市、兴平市与夏季宝鸡市、眉县、兴平市附近采样点硝酸盐氮浓度超过生活饮用水卫生标准(GB 5749-2022)规定的10 mg·L^(-1),两季超标率分别为20%和30%,超标样品δ^(15)N范围为+1.33%~+14.36%.地下水硝酸盐氮的主要来源是粪便及污废水、化肥以及土壤有机氮,以上来源对冬季地下水硝酸盐氮的贡献率分别为42.73%、22.99%和21.84%,对夏季的贡献率分别为40.34%、36.97%和18.02%,大气沉降在两季对地下水氮污染的贡献最小.冬季氮转化的主要过程是硝化作用与异化硝酸盐还原作用(DNRA),而夏季的主导过程为硝化作用,异化硝酸盐还原作用相对较弱.提高生活污废水收集效率,改善化粪池管理,推广有机肥料的施用,提高肥料与土壤中氮利用效率是减少渭河流域地下水硝酸盐氮的重要举措.

关键词：地下水氮污染氮氧双同位素迁移转化季节性变化

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Report on 3,143.6-km Time and Frequency Transfer Fiber Link with Ps-level Stability

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Chinese Physics Letters 2025年第1期42卷 68-72页

作者： bo Liu Xinxing Guo Jiang Chen Yanli Zhou Tao Liu Ruifang Dong Shougang zhang National Time Service Center Chinese Academy of SciencesXi'an 710600China University of Chinese Academy of Sciences Beijing 100039China Key Laboratory of Time Reference and Applications Chinese Academy of SciencesXi'an 710600China China Mobile Communications Group Shaanxi Co. LtdXi'an 710600China

This letter describes the implementation of a high-precision time and frequency transmission system using a two-way and wavelength division multiplexing scheme over 3,143.6 km of field fiber links,connecting 21 sites between Xi’an and Beijing,*** scheme incorporates a link noise clean-up system(LNCUS),wherein a controlled very-low-phase noise BVA oscillator acts as an internal frequency source at the relay site to effectively suppress the interference caused by the fiber link ***,the high-stability pulse generation technology in the LNCPS provides sufficient short-term stability to significantly improve the stability of the fiber time *** results indicate a time transfer stability in terms of time deviation(TDEV)of less than2.07 ps@1s,5.9 ps@100,000s,and combined uncertainty of less than 49.29 ps for the 3,143.6 km field fiber *** results represent a significant breakthrough in achieving high-accuracy time transfer and continuous operation over ultralong-span field optical fibers exceeding 3,000 km for the first *** enabled time transfer and synchronization services over the longest international optical fiber distance,thereby establishing a fundamental basis for constructing a nationwide high-precision time service through optical fiber networks.

关键词： fiber breakthrough exceeding

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