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Selective and facile deacetylation of pentacyclic triterpenoid under methanolic ammonia condition and unambiguous NMR analysis

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Chinese Chemical Letters 2020年第2期31卷 333-336页

作者： Han Wang Renyang Xu Shuobin Liang fuxiang ran Lihe Zhang Yongmin Zhang Demin Zhou Sulong Xiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Department of Pharmacy The Second Affiliated HospitalDalian Medical UniversityDalian 116023China Sorbonne Université Institut Parisien de Chimie MoléculaireCNRS UMR 82324 place Jussieu75005 ParisFrance

The acetyl ester plays an important role for protection of the hydroxyl groups in carbohydrates *** the present study,we described an efficient deprotection of acetyl group of pentacyclic triterpenoid by using methanolic ammonia in THF *** selectivity for cleaving gal-C2-OAc group of 3β-hydroxy-olean-12-en-28-oic acid 28-N-2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside(3) was achieved in the presence of methanolic ammonia within 4 h at low temperature(-60℃) in a yield of 56%.The reaction disclosed here provides a new method for the synthesis of C2 selective modified carbohydrates,which is more useful than conventional synthesis procedure that usually requires many steps including temporary regioselective protection and *** the reaction temperature was increased from -60℃ to room temperature,the cleavage of the other three acetyl groups of galactose in an order of C4-OAc>C3-OAc>C6-OAc was *** on this study,a plausible route for the deacetylation reaction has been proposed.

关键词： Pentacyclic triterpenoid Deacetylation Methanolic ammonia Selectivity Synthesis

Facile preparation and characterization of novel oleanane-type triterpene functionalized β-cyclodextrin conjugates

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Chinese Chemical Letters 2019年第3期30卷 690-693页

作者： Pingxuan Jiao Shouxin Wang Shuobin Liang Man Li Qianqian Gao Dezhong Ji Yingying Chen Haiwei Li fuxiang ran Yongmin Zhang Lihe Zhang Demin Zhou Sulong Xiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University School of Pharmacy Jining Medical University Sorbonne Universite Institut Parisien de Chimie Moleculaire CNRS UMR 8232 State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences

Oleanolic acid(OA) and echinocystic acid(EA), two naturally occurring pentacyclic oleanane triterpenes,are gaining increasing attention due to their promising pharmacological activities. Conjugation with amphiphilic α(β)-cyclodextrin(CD) via "click chemistry" can improve their solubility and anti-HCV entry potency. In the present work,four water-soluble β-CD-pentacyclic triterpene conjugates were designed and synthesized, in which OA and EA was coupled to one of the primary hydroxyl groups of β-CD via ester and amide bonds. The structures of the conjugates were unambiguously determined by ~1H NMR, ^(13)C NMR and HRMS or MALDI-TOF-MS. All the conjugates showed lower hydrophobicity(AlogP) than their parent compounds and no significant cytotoxicity was found to HL-60, A549, Hela and Bel-7402 cells at concentrations up to 10 μmol/L. Further anti-HCV entry activity and mechanism studies are under way in our laboratory.

关键词： β-Cyclodextrin DIBAL-H Oleanolic acid Echinocystic acid Synthesis

Treatment of severe radiation proctitis with high dosage of vitamin C in combination with cyclooxygenase-2 inhibitor

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Radiation Medicine and Protection 2024年第2期5卷 113-117页

作者： Han Wu Miaomiao Liu Huangang Jiang Hui Xu Jin Peng Jing Dai fuxiang Zhou Department of Radiation and Medical Oncology Zhongnan HospitalWuhan UniversityWuhan 430007China Hubei Key Laboratory of Tumor Biological Behaviors Zhongnan HospitalWuhan UniversityWuhan 430007China Hubei Clinical Cancer Study Center Zhongnan Hospital of Wuhan UniversityWuhan 430007China

Objective:To explore the new treatment strategies for radiation proctitis,which is the most common complication of pelvic tumor ***:Four cases of patients with severe radiation proctitis were treated with high-dosage vitamin C(VC,12–24 g/d,iv)combined with cyclooxygenase-2(cyclooxygenase-2,COX-2)***:For these four cases,the diarrhea,hematochezia,tenesmus,pain,and other symptoms were significantly *** edema of the rectal wall is also significantly improved in the imaging ***:The high-dosage VC combined with the treatment of severe radiation proctitis is safe and effective.

关键词： Radiation proctitis Vitamin C Cyclooxygenase-2 inhibitor Radiotherapy

Coupling of Adhesion and Anti‑Freezing Properties in Hydrogel Electrolytes for Low‑Temperature Aqueous‑Based Hybrid Capacitors

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Nano-Micro Letters 2024年第2期16卷 15-31页

作者： Jingya Nan Yue Sun Fusheng Yang Yijing Zhang Yuxi Li Zihao Wang Chuchu Wang Dingkun Wang fuxiang Chu Chunpeng Wang Tianyu Zhu Jianchun Jiang Institute of Chemical Industry of Forest Products Chinese Academy of ForestryKey Laboratory of Biomass Energy and MaterialJiangsu ProvinceNanjing 210042JiangsuPeople’s Republic of China Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037JiangsuPeople’s Republic of China Energy Technologies Area Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Department of Materials Science and Engineering Clemson UniversityClemsonSC 29634USA

Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety,mechanical and thermal stability and easy-to-direct *** electrolytes are appealing solid-state electrolytes because of eco-friendliness,high conductivity and intrinsic ***,the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion ***,we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing *** synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and ***,the cooperative solvation of ZnCl2 and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low *** significantly,the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance,delivering high-energy density of 39 Wh kg^(-1)at-60°C with capacity retention of 98.7%over 10,000 *** the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte,the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at-60°*** work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.

关键词： Interfacial adhesion Anti-freezing Hydrogel electrolytes Low-temperature hybrid capacitors Dynamic deformati

小陇山林区实施天然林保护工程成效与对策探析

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林业资源管理 2009年第2期 21-27页

作者：冉福祥甘肃林业职业技术学院

在全面调查林区实施天然林保护工程取得成效的基础上,以森林可持续经营理论为指导,综合运用科学分类和归纳的方法,分析了林区天然林保护工程在工程设计、实施与管理过程中存在的问题。分析得知,甘肃省小陇山林区天然林保护工程实施以来... 详细信息

在全面调查林区实施天然林保护工程取得成效的基础上,以森林可持续经营理论为指导,综合运用科学分类和归纳的方法,分析了林区天然林保护工程在工程设计、实施与管理过程中存在的问题。分析得知,甘肃省小陇山林区天然林保护工程实施以来成效显著,但在工程经营管理上仍存在管理体制不顺、经营管理水平较低、思想观念落后等问题。根据实际,提出了解决天然林保护区实际问题的对策:加大科技投入,提高工程实施的科技含量;完善法律监督机制,强化天然林保护工程管理;加快发展天保工程区后续产业,提高天然林区自我发展能力。

关键词：天然林保护工程实施成效问题分析对策小陇山林区

Isolation and characterization of mpox virus from the first mpox case in Shenzhen,China

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Virologica Sinica 2024年第2期39卷 335-337页

作者： Lin Cheng Liuqing Yang Miao Wang Yabo Peng Haiyan Wang Xiaoxiang Yang Juanjuan Zhao Mingxia Zhang fuxiang Wang Zheng Zhang Institute for Hepatology National Clinical Research Center for Infectious DiseaseShenzhen Third People's HospitalShenzhen518112China Department of Infectious Diseases Shenzhen Third People's HospitalShenzhen 518112China The Second Affiliated Hospital School of MedicineSouthern University of Science and TechnologyShenzhen 518112China

Dear Editor,Unlike previous outbreaks of the mpox(previously known as monkeypox),which were localized in Africa and resulted in small numbers of infections due to limited human-to-human transmission,the current outbreak beginning in May 2022,has spread rapidly primarily through human-to-human transmission in non-endemic countries(Gong et al.,2022).As of 27 Sep 2023,115 countries and regions have reported cases of mpox to the World Health Organization(WHO),bringing the total number of confirmed cases to 90,618 including 125 *** the number of new cases has decreased in most WHO regions in the second half of 2022,the curves reveal a long outbreak tail in different subregions of the *** worrying,106 mpox cases were reported in the mainland of China in June 2023.

关键词： mainland bringing

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密度泛函理论在光催化中的普遍应用

Chinese Journal of Catalysis 2024年第6期61卷 1-36页

作者：杜仕文章福祥中国科学院大连化学物理研究所催化基础国家重点实验室洁净能源国家实验室能源材料化学协同创新中心辽宁大连116023

在低碳发展的背景下,开发利用清洁无污染的太阳能对满足未来日益增长的能源需求至关重要.半导体光催化技术可将太阳能转化为化学能,为可再生能源的发展提供了重要支持.因此,深入理解光催化剂与光催化活性之间的内在关联,对于优化和提升... 详细信息

在低碳发展的背景下,开发利用清洁无污染的太阳能对满足未来日益增长的能源需求至关重要.半导体光催化技术可将太阳能转化为化学能,为可再生能源的发展提供了重要支持.因此,深入理解光催化剂与光催化活性之间的内在关联,对于优化和提升光催化效率至关重要.尽管科研人员在设计开发用于光催化反应的新材料方面付出了巨大努力,但对半导体的内在性质、表面活性位点和催化反应机理之间的深层次联系,仍缺乏充分的理解和认识.基于密度泛函理论(DFT)的第一性原理计算是揭示材料内禀电子结构性质和反应过程能量变化的重要工具,正逐渐获得研究者的广泛关注.并且,随着计算方法的不断优化,该领域也取得了显著的进步.本文通过系统梳理国内外代表性研究工作,深入探讨了DFT计算在光催化领域中的广泛应用.首先,总结了DFT计算在光催化领域中的六大优势:(1)预测光催化材料的电子结构,如能带结构、能带间隙和能级;(2)预测表面反应的吸附位点、吸附能等变化;(3)在原子水平上揭示电荷转移过程,包括电子和空穴的运动;(4)阐明光催化剂与底物之间的相互作用;(5)预测光催化材料中空位、间隙和掺杂等缺陷的形成及其影响;(6)阐明光催化反应的机理细节,包括中间物种、过渡态和反应途径等.接着,简要概述了常用于第一性原理计算的软件和计算方法,并特别关注了如何利用不同策略来纠正传统DFT方法对半导体电子结构特性的不适当估计.随后,分析了基于DFT计算的半导体电子和能量特性的典型研究案例,如能带结构、态密度、电荷分布、功函数、形成能和吸附自由能等.此外,还详细阐述了半导体催化剂在多种太阳能驱动反应中的基本应用,包括析氢反应、析氧反应、氧还原反应、CO_(2)还原反应和氮还原反应等.最后,指出了DFT计算在光催化研究中的机遇与挑战,并展望了未来可能的发展方向.综上,本文系统综述了DFT计算在光催化领域中的广泛应用,旨在深入理解光催化反应中“组成-结构-功能”之间的关系,并为未来开发设计用于太阳能到化学能催化转化的高效稳定催化剂提供参考.

关键词：光催化密度泛函理论第一性原理计算电子结构能量性质

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也谈语境吸收

汉语学报 2024年第1期 18-30页

作者：吴福祥北京语言大学语言科学院 100083

语境吸收作为语义演变的一种机制,近些年来在汉语研究文献中被反复提及。本文认为,语境吸收本质上是一种高度受限、较为特殊的语义演变现象,在汉语中真正合格的例证也非常少见。惟其如此,语境吸收只可能是语义演变的一种途径或结果,不... 详细信息

语境吸收作为语义演变的一种机制,近些年来在汉语研究文献中被反复提及。本文认为,语境吸收本质上是一种高度受限、较为特殊的语义演变现象,在汉语中真正合格的例证也非常少见。惟其如此,语境吸收只可能是语义演变的一种途径或结果,不可能是语义演变的机制。此外,本文主张,跟其他语义演变过程一样,语境吸收也涉及语用推理(共时)和语义化等过程。

关键词：语境吸收语用推理语义化语义演变

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路易十五“中国题材”挂毯寻踪

故宫博物院院刊 2024年第4期 53-65,144页

作者：郭福祥故宫博物院宫廷历史部

本文利用新发现的档案和实物材料,推断路易十五送给乾隆皇帝的“中国题材”挂毯至少有四件尚存于世。作者通过对故宫博物院藏四件玻璃底片上的挂毯照片,与欧洲现存“中国题材”挂毯实物和设计原稿进行对比,发现路易十五送给乾隆皇帝的... 详细信息

本文利用新发现的档案和实物材料,推断路易十五送给乾隆皇帝的“中国题材”挂毯至少有四件尚存于世。作者通过对故宫博物院藏四件玻璃底片上的挂毯照片,与欧洲现存“中国题材”挂毯实物和设计原稿进行对比,发现路易十五送给乾隆皇帝的这套挂毯在规格和图像内容上都作了相当大的改动。这种改动显示出法国将其作为国礼时所进行的变通。相关信息的追踪,不但丰富了我们对“中国题材”挂毯织作史和流通史的认识,也为探讨中法宫廷交往和文化交流提供了丰富的细节线索和样本。

关键词：中国题材挂毯壁衣玻璃底片中法宫廷交往礼品