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The ultratrace detection of crystal violet using surface enhanced Raman scattering on colloidal Ag nanoparticles prepared by electrolysis

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Chinese Chemical Letters 2009年第6期20卷 711-715页

作者： Ren ming Liu Yi Pu Kang Xing Fa zi ming Jun feng Man Cheng Min Zhen Si Application Institute of Spectroscopy Technology Chuxiong Normal University Chuxiong 675000 China

Highly active, stable and affordable surface enhanced Raman scattering （SERS） substrates were obtained by electrolyzing a mixture of AgNO3 （4 × 10^-4 mol/L） and Na3C6H5OTH2O （6 × 10^-5 mol/L） for 1, 2, 3 and 4 h at 7 V. With crystal violet （CV） as a test molecule, a portable Raman spectrometer with 785 nm laser excitation was employed to carry out the SERS detection. Colloidal Ag nanoparticles prepared by electrolyzing for 3 h with the particle size of （65 ±17） nm is a perfect SERS substrate for the ultratrace detection of CV, which displayed an enhancement factor of ca. 1.3 × 10^8 and the detection limit of CV is down to ca. 10-15 mol/L （ca. 10^-4 ppb） with 10^-1 mol/L KBr as aggregating agent. Thus, this SERS substrate will provide a hopeful foreground in ultratrace detection. Meanwhile, it will provide a possibility to bring Raman analysis out of the laboratory to process in situ, real-time detection and identification.

关键词： SERS Ultratrace detection Crystal violet Silver nanoparticle Electrolysis

Sesquiterpenoid and C14-polyacetylene glycosides from the rhizomes of Atractylodes lancea

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Chinese Chemical Letters 2017年第3期28卷 597-601页

作者： Kuo Xu zi-ming feng Jian-Shuang Jiang Ya-Nan Yang Pei-Cheng Zhang State Key Laboratory of Bioactive Substance and Function of Natural Medidnes Institute of Materia Medica Peking Union Medical College and Chinese Academy of Medical Sdences BeUing 100050 China

Four new glycosides including a eudesmane-type sesquiterpenoid（1）, a guaiane-type sesquiterpenoid（2）, and two C_（14）-polyacetylenes（3, 4） were isolated from the rhizomes of Atractylodes lancea. Their structures were elucidated by means of spectroscopic and spectrometric analyses（UV, IR, 1D and 2D NMR, and HR-ESIMS）. The absolute configurations of their aglycones were established based on the experimental and calculated electronic circular dichroism（ECD）, whereas those of monosaccharide moieties were determined by the GC method after chiral derivatization. Compound 4 showed weak anti-inflammatory effects on the LPS-induced NO production in microglia BV2 cells at a concentration of10μmmolL^（-1）.

关键词： Atractylodes lancea Eudesmane-type sesquiterpenoid Guaiane-type sesquiterpenoid C_(14)-Polyacetylene Anti-inflammatory effect

Indole Alkaloids from the Roots of Ervatamia hainanensis

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Chinese Chemical Letters 2006年第6期17卷 779-782页

作者： Jian Peng HUANG zi ming feng Chong Fei ZHENG Pei Cheng ZHANG Yang Min MA Institute of Materia Medica Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 College of Life Science Northwest A-F University Yangling Shaanxi 712100

Two new indole alkaloids, named ibogamine-18-carboxylic acid, 3, 4-didehydro-7, 8-dioxo-methyl ester 1, ibogamine-18-carboxylic acid, 16, 17-didehydro-9, 17-dihydro-9-hydroxy （2-oxopropyl）-methyl ester 2, were isola... 详细信息

关键词： Ervatamia hainanensis indole alkaloid ibogamine-18-carboxylic acid 3 4-didehydro-7 8-dioxo-methyl ester ibogamine- 18-carboxylic acid 16 17-didehydro-9 17-dihydro-9-hydroxy-(2-oxopropyl)-methyl ester.

Five Novel Pterocarpan Derivatives from Sophora flavescens

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Chinese Journal of Chemistry 2021年第10期39卷 2763-2768页

作者： Kai-Zhou Lu zi-ming feng Xiang Yuan Ya-Nan Yang Jian-Shuang Jiang Xu Zhang Pei-Cheng Zhang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing100050 China

Main observation and conclusion Five novel pterocarpan derivatives(1—5)and three known pterocarpans were isolated from the roots of Sophora flavescens *** structures were elucidated based on extensive spectroscopic data(UV,IR,1D and 2D NMR,and HR-ESI-MS).Notably,compounds 1—5 were the first reported natural products,which possess unique pterocarpan-glucose-long chain aliphatic acid *** kinds of aliphatic acids were determined by comparison with authentic aliphatic acids using HPLC-ELSD analysis after acid *** absolute configurations of 1—5 were confirmed by analysis of their ECD *** compounds were evaluated against lipopolysaccharide(LPS)-induced TNF-αproduction in RAW264.7 cells,and compound 1 showed significant inhibitory activity with inhibition rate of 86.22%,IC_(50)=0.79μmol/L(dexamethasone as positive control,inhibition rate of 71.38%).

关键词： Sophora flavescens Pterocarpan derivatives Natural products Structure elucidation Biological activity

Detecting Marionette Microblog Users for Improved Information Credibility

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Journal of Computer Science & Technology 2015年第5期30卷 1082-1096页

作者：吴贤范伟高晶冯子明俞勇 Department of Computer Science Shanghai Jiao Tong University Shanghai 200240 China Baidu Research Big Data Laboratory Sunnyvale CA 94089 U.S.A. Department of Coraputer Science and Engineering University at Buffalo Buffalo NY 14214 U.S.A.

In this paper, we propose to detect a special group of microblog users： the ＂marionette＂ users, who are created or employed by backstage ＂puppeteers＂, either through programs or manually. Unlike normal users that access microblog for information sharing or social communication, the marionette users perform specific tasks to earn financial profits. For example, they follow certain users to increase their ＂statistical popularity＂, or retweet some tweets to amplify their ＂statistical impact＂. The fabricated follower or retweet counts not only mislead normal users to wrong information, but also seriously impair microblog-based applications, such as hot tweets selection and expert finding. In this paper, we study the important problem of detecting marionette users on microblog platforms. This problem is challenging because puppeteers are employing complicated strategies to generate marionette users that present similar behaviors as normal users. To tackle this challenge, we propose to take into account two types of discriminative information： 1） individual user tweeting behavior and 2） the social interactions among users. By integrating both information into a semi-supervised probabilistic model, we can effectively distinguish marionette users from normal ones. By applying the proposed model to one of the most popular microblog platforms （Sina Weibo） in China, we find that the model can detect marionette users with F-measure close to 0.9. In addition, we apply the proposed model to calculate the marionette ratio of the top 200 most followed microbloggers and the top 50 most retweeted posts in Sina Weibo. To accelerate the detecting speed and reduce feature generation cost, we further propose a light-weight model which utilizes fewer features to identify marionettes from retweeters.

关键词： marionette microblog user information credibility fake follower fake retweet

Supramolecular polymer network constructed by a functionalized polyimidazolium salt derived from metal-carbene template approach

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Science China Chemistry 2024年第4期67卷 1224-1228页

作者： ming-ming Gan zi-En Zhang Yi-Fan Zhang Heng Zhang Li-Ying Sun Ying-feng Han Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China

In this study,we present a supramolecular templating approach for constructing polyimidazolium salt containing crown ether and cyclobutane *** strategy involves the formation of metal-carbene templates,photochemical cycloaddition,and subsequent demetallation of metal *** by the host-guest chemistry between crown ether units and ammonium salts,we successfully fabricated a supramolecular polymer SPN1,which features imidazolium receptors and cyclobutane *** obtained SPN1 demonstrates outstanding reversible stimulus-response,antibacterial behavior and conductivity.

关键词： metal-carbene template crown ether polyimidazolium salt host-guest chemistry

Arnequinol A and arnequinone A, two unique meroterpenoids from Arnebia euchroma

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Chinese Chemical Letters 2022年第5期33卷 2555-2558页

作者： Hai-Wei Yan Rong-Rong Du Xu Zhang Ya-Nan Yang Xiang Yuan zi-ming feng Jian-Shuang Jiang Pei-Cheng Zhang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Arnequinol A(1),featuring an unprecedented 6/6/3 tricyclic carbon skeleton fused with a heptatomic oxo-bridge,together with arnequinone A(2)bearing a highly conjugated methyl-shifting benzogeijerene skeleton,were isolated from Arnebia *** structures were elucidated by extensive spectro-scopic methods and quantum chemical calculations of the 13 C nuclear magnetic resonance(NMR)data and electronic circular dichroism(ECD)*** plausible biosynthetic pathways for 1 and 2 were *** in vitro test,compound 2 showed potent neuroprotective activity against serum-deprivation induced PC12 cell damage at a concentration of 10μmol/L.

关键词： Arnebia euchroma Meroterpenoids Arnequinol A and arnequinone A Cytotoxicity Neuroprotective activity

Synthesis and cytotoxic activity of heterocycle-substituted phthalimide derivatives

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Chinese Chemical Letters 2010年第8期21卷 902-904页

作者： Ya Jun Yang Ya Nan Yang Jian Shuang Jiang zi ming feng Hong Yan Liu Xian Dao Pan Pei Cheng Zhang Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine(Ministry of Education) Institute of Materia MedicaPeking Union Medical College and Chinese Academy of Medical SciencesBeijing 100050China Beijing Union Pharmaceutical Factory Beijing 102600China

A series of heterocycle-substituted phthalimide derivatives were *** diverse derivatives with heterocyclic rings,including furan,imidazo[1,2-a]pyridine,1,3,4-thiadiazine,imidazo[2,1-b][1,3,4]thiadiazine,pyrazole,1,2,4-triazolo[3,4- b][1,3,4]thiadiazine,thiazole and thiazoline,were obtained by the reactions ofα-bromoketone intermediate with various nucleophiles containing oxygen,nitrogen and sulfur *** cytotoxic activity was also evaluated against five human cancer cell lines in vitro.

关键词： Phthalimide Heterocycle α-Bromoketone Cytotoxic activity

Weyl Type Theorem for Bounded Linear Operator and Its Functional Calculus

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Acta Mathematica Sinica,English Series 2024年第2期40卷 528-536页

作者： Gao Hui zi feng Peng Tong LI School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

Let H be a complex infinite dimensional Hilbert space and B(H)be the algebra of all bounded linear operators on *** this paper,we mainly study the operators that satisfy both a-Weyl's theorem and property(R).Also,the operators whose functional calculus satisfies the two properties are also *** give the features for the operator or its functional calculus for which both a-Weyl's theorem and property(R)hold.

关键词： a-Weyl's theorem property(R) functional calculus