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Discovery of Natural Co-occurring Enantiomers of Monoterpenoid Indole Alkaloids

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Chinese Journal of Chemistry 2021年第4期39卷 866-872页

作者： Yang yu Mei-Fen bao Xiang-hai Cai State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan650201 China

Main observation and conclusion Two new pairs of monoterpenoid indole alkaloids(MIAs)enantiomers as well as their new congeners were isolated from stems of Tabernaemontana bovina Lour.(Apocynaceae).Their structures were elucidated by spectroscopic analyses and confirmed by X-ray diffractions and computational calculations.Tabovine A,tabovine B and tabovines C-D possessed unprecedented 6/5/5/6/6,6/5/5/6/5 and 6/5/6/6/6 ring systems,respectively.It is the first time to report co-occurring enantiomers of MIAs.Additionally,the explanation concerning biogenesis of MIAs was provided.The findings would open a new window where we could disclose more diverse MIAs.

关键词： Monoterpenoid indole alkaloid Enantiomers Tabovines A-D Structure elucidation Extraction and isolation

Soil anti-scourability enhanced by herbaceous species roots in a reservoir water level fluctuation zone

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Journal of Mountain Science 2021年第2期18卷 392-406页

作者： XU Wen-xiu YANG Ling BAO Yu-hai LI Jin-lin WEI Jie Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China School of Geography and Tourism Science Chongqing Normal UniversityChongqing 401331China University of Chinese Academy of Sciences Beijing 100049China

Revegetation is one of the successful approaches to soil consolidation and streambank protection in reservoir water level fluctuation zones(WLFZs).However,little research has been conducted to explore the impact of herbaceous species roots on soil anti-scourability during different growth stages and under different degrees of inundation in this zone.This study sampled two typical grasslands(Hemarthria compressa grassland and Xanthium sibiricum grassland)at two elevations(172 and 165 m a.s.l.)in the water level fluctuation zone(WLFZ)in the Three Gorges Reservoir(TGR)of China to quantify the changes in soil and root properties and their effects on soil anti-scourability.A simulated scouring experiment was conducted to test the soil anti-scourability in April and August of 2018.The results showed that the discrepancy in inundation duration and predominant herbaceous species was associated with a difference in root biomass between the two grasslands.The root weight density(RWD)values in the topsoil(0-10 cm)ranged from 7.31 to 13 mg cm^(-3) for the Hemarthria compressa grassland,while smaller values ranging from 0.48 to 8.61 mg cm^(-3) were observed for the Xanthium sibiricum grassland.In addition,the root biomass of the two herbs was significantly greater at 172 m a.***.l.than that at 165 m a.***.l.in the early recovery growth period(April).Both herbs can effectively improve the soil properties;the organic matter contents of the grasslands were 128.06%to 191.99%higher than that in the bare land(CK),while the increase in the water-stable aggregate ranged from 8.21%to 18.56%.Similarly,the topsoil antiscourability indices in both the herbaceous grasslands were larger than those in the CK.The correlation coefficients between the root length density(RLD),root surface area density(RSAD)and root volume density(RVD)of fine roots and the soil antiscourability index were 0.501,0.776 and 0.936,respectively.Moreover,the change in the soil antiscourability index was more sensitive to alternations in the RLD with diameters less than 0

关键词： Herbaceous species root system Soil anti-scourability Water level fluctuation zone Three Gorges Reservoir

Monoterpenoid Indole Alkaloids with Promoting Neurite Growth from Tabernaemontana divaricata

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Chinese Journal of Chemistry 2021年第5期39卷 1085-1092页

作者： Yan Deng Yang yu bao-bao Shi Mei-Fen bao Si-Meng Zhao Xiang-hai Cai State Key Laboratory of Phytochemistry and Plant Resources in West Chino Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China iHumon Institute ShanghaiTech UniversityShanghai 200031China

Phytochemical investigations on Tabernaemontana divaricata led to the isolation of seven undescribed monoterpenoid indole alkaloids,taberdicatines A-G(1-7).Taberdicatines A-C might be derived from Aspidosperma-type alkaloid,less skeletal carbons in 1-2 and an additional carbon in 3.Taberdicatines D-E(4-5)were attributed to Iboga alkaloids with enantiomeric skeleton,respectively.Alkaloid 3 could promote the neurite growth of mouse primary cortical neurons at the concentration of 5 pimol/L.

关键词： Monoterpenoid indole alkaloid Taberdicatines A-G Structure elucidation Extraction and isolation Promoting neurite growth

Flow stress model considering the transformation-induced plasticity effect and the inelastic strain recovery behavior

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International Journal of Minerals,Metallurgy and Materials 2011年第2期18卷 185-191页

作者： hai-yan yu Li bao School of Automotive Engineering Tongji University Shanghai 200092 China

On the basis of continuum mechanics and the Mori-Tanaka mean field theory, a micro-mechanical flow stress model that considered both the transformation-induced plasticity （TRIP） effect and the inelastic strain recovery behavior of TRIP multiphase steels was presented. The relation between the volume fraction of constituent phases and plastic strain was introduced to characterize the transformation-induced plasticity effect of TRIP steels. Loading-unloading-reloading uniaxial tension tests of TRIP600 steel were carried out and the strain recovery behavior after unloading was analyzed. From the experimental data, an empirical elastic modulus expression is extracted to characterize the inelastic strain recovery. A comparison of the predicted flow stress with the experimental data shows a good agreement. The mechanism of the transformation-induced plasticity effect and the inelastic recovery effect acting on the flow stress is also discussed in detail.

关键词： flow stress transformation-induced plasticity inelastic strain elastic modulus

A thermochemical model description of CaO-SiO2-Al2O3 silicate system

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China Foundry 2023年第6期20卷 480-490页

作者： Qiu-lin Wen Feng-man Shen hai-yan Zheng yun-bao Gao yu Wang Yan-chun Lou National Key Laboratory of Advanced Casting Technologies Liaoning Academy of Materials 3. School of Metallurgy Northeastern University

A thermochemical model based on the ion and molecule coexistence theory(IMCT) was developed to calculate thermodynamic data in the CaO-SiO2-Al2O3slag system, considering the influential role of oxide activities on the thermodynamic properties of slags. Using this model, iso-activity contours were obtained for oxide components CaO, SiO2and Al2O3in this system at temperatures of 1,873 K and 1,773 K. When compared with the IMCT model, it is found that the predicted activities of oxide components in the CaO-SiO2-Al2O3system using the model developed in this study better matches experimental data from literature in terms of both trend and numerical value. Therefore, the model developed in this study can serve as a robust modeling tool for metallurgical processes, and the thermodynamic data predicted by this new model can be used to improve the metallurgical technology.

关键词： thermochemical model CaO-SiO 2 -Al 2 O 3 slag system thermodynamic properties molecule coexistence theory TG223 A

Homogeneous nitrogen-doped(111)-type layered Sr5Nb4O15-xNx as a visible-light-responsive photocatalyst for water oxidation

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Nano Research 2022年第12期15卷 9976-9984页

作者： Shiwen Du hai Zou yunfeng bao yu Qi Xueshang Xin Shuowen Wang Zhaochi Feng Fuxiang Zhang State Key Laboratory of Catalysis Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China University of Chinese Academy of Sciences Beijing100049China

The development of visible-light-responsive photocatalysts for promoting solar-driven oxygen(O2)production from water splitting is a potentially attractive but still a challenging scheme.In the present work,a(111)-type layered perovskite oxynitride,Sr5Nb4O15-xNx,was synthesized via the nitridation treatment of the disk-like oxide precursor under the ammonia flow,which was fabricated using a flux method.The homogeneous dispersion of nitrogen(N)dopant in N-doped Sr5Nb4O15 was ascertained by energy-dispersive X-ray spectroscopy characterization,and the Sr5Nb4O15-xNx was found to be a direct semiconductor with a light absorption edge of approximately 640 nm.Density functional theory investigation implies that the hybridization between the outmost N 2p orbitals and O 2p orbitals upshifts the original valence band maximum of Sr5Nb4O15 and endows its visible-light-responsive characteristics.Loading with cobalt oxide(CoOx)as cocatalyst,the as-prepared Sr5Nb4O15-xNx exhibited an enhanced photocatalytic O2 evolution activity from water splitting under visible-light illumination(λ>420 nm).Moreover,another homogeneous N-doped layered perovskite-type niobium(Nb)-based oxynitride,Ba5Nb4O15-xNx,was also developed and investigated for the visible-light-actuated O2 production,highlighting the versatility of the present approach for exploring novel visible-light-responsive photocatalysts.

关键词： nitrogen-doped visible-light-responsive layered perovskite oxygen(O2)evolution water splitting

植物多样性而非其土壤遗留效应影响外来植物入侵

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Journal of Plant Ecology 2022年第3期15卷 639-649页

作者： Wei Xue Si-Mei Yao Lin Huang Sergio RRoiloa bao-Ming Ji Fei-hai yu Institute of Wetland Ecology&Clone Ecology/Zhejiang Provincial Key Laboratory of Evolutionary Ecology and Conservation Taizhou UniversityTaizhou 318000China BioCost Group Biology DepartmentUniversidade da CoruñaA Coruña 15071Spain School of Grassland Science Beijing Forestry UniversityBeijing 100083China

植物多样性可以影响外来植物入侵,然而植物多样性的土壤遗留效应是否能够影响外来植物入侵目前仍不清楚。植物多样性能够改变土壤微生物群落和土壤理化性质,这种遗留效应可能会对该土壤中外来植物的生长产生影响。因此,我们假设植物多... 详细信息

植物多样性可以影响外来植物入侵,然而植物多样性的土壤遗留效应是否能够影响外来植物入侵目前仍不清楚。植物多样性能够改变土壤微生物群落和土壤理化性质,这种遗留效应可能会对该土壤中外来植物的生长产生影响。因此,我们假设植物多样性的土壤遗留效应会影响外来植物的入侵。为了检验该假说,我们开展了一个两阶段的植物-土壤反馈实验。在土壤驯化阶段,我们将12个植物物种(4种禾草植物、3种豆科植物和5种杂类草植物)分别单独种植,或者随机选择8个物种(包含3个功能型)混合种植在土壤中。在反馈阶段,我们将入侵植物三叶鬼针草(Bidens pilosa)分别与本地禾草荩草(Arthraxon hispidus)、本地杂类草翅果菊(Pterocypsela indica)或者同时与荩草和翅果菊种植在被驯化过的土壤中。研究结果显示,三叶鬼针草相对于其本地竞争植物的生长取决于驯化植物和竞争植物物种的功能型。驯化植物的多样性对三叶鬼针草与其本地竞争植物之间的生长差异没有显著影响。然而,随着本地竞争植物物种多样性的增加,三叶鬼针草相对于其本地竞争植物的生长显著降低。这些结果表明,当前的植物多样性可以通过增加入侵植物和本地植物之间的生长不平衡性来减少外来植物的入侵。但是,植物多样性的土壤遗留效应对外来植物入侵的影响可能很小。

关键词：三叶鬼针草(Bidens pilosa) 竞争平衡多样性效应入侵植物植物-土壤反馈

Research on proximity effect of electromagnetic railgun

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Defence Technology（防务技术） 2016年第3期12卷 223-226页

作者： yu-tao LOU hai-yuan LI bao-ming LI National Key Laboratory of Transient Physics Nanjing University of Science and Technology

The rails of electromagnetic railgun can be ablated by the temperature rise due to current concentration.The current distributions on the rails and armature are not only affected by the skin effect,but also influenced by the proximity effect which is rarely mentioned.This paper illustrated the difference between skin effect and proximity effect,and the influencing factors of proximity effect were investigated.Results show that the current is concentrated on the surface around rails due to the skin effect,and the proximity effect exacerbates the current density on the inner surfaces of rails.Decrease in distance from rails enhances the proximity effect,but has nothing to do with the skin effect,which also augments the rail resistance,resulting in temperature rise.It can explain the reason why the ablation is often detected in the small caliber railgun.Research results in this paper can provide support for design and optimization of electromagnetic railgun.

关键词： Electromagnetic railgun Proximity effect Skin effect Ablation

Association between serum cartilage oligomeric matrix protein and coronary artery calcification in maintenance hemodialysis patients

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Journal of Geriatric Cardiology 2020年第2期17卷 67-73页

作者： Lahati HA Jun-bao SHI hai-Yi yu Kun YANG hai-Ning WANG Fang-Fang WANG Jiang-Li HAN Department of Cardiology and Institute of Vascular Medicine Peking University Third HospitalNHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory PeptidesKey Laboratory of Molecular Cardiovascular ScienceMinistry of EducationBeijing Key Laboratory of Cardiovascular Receptors ResearchBeijingChina Department of Nephrology Peking University Third HospitalBeijingChina Department of Endocrinology Peking University Third HospitalBeijingChina

Background Coronary artery calcification(CAC)is common in end-stage renal disease(ESRD)patients,and the extent of CAC is closely related to cardiovascular outcomes in ESRD patients.Cartilage oligomeric matrix protein(COMP),as a component of the vascular matrix,has been found to be an inhibitor of arterial calcification in basic studies.However,there is no clinical research on the correlation between COMP and CAC in maintenance hemodialysis(MHD)patients.The aim of this study was to explore the relationship between serum COMP levels and CAC and cardiovascular events in MHD patients.Methods Serum COMP levels were compared between 54 MHD patients and 66 healthy people.MHD patients were then divided into three groups according to the tertiles of the concentration of COMP level and were followed up for major adverse cardiac events(MACEs),which were defined as a combined end point of new onset angina pectoris,nonfatal myocardial infarction,heart failure,coronary artery revascularization,hospitalization due to angina pectoris and all-cause deaths.The CAC score was calculated based on computed tomography scans.Results The serum COMP level in MHD patients was significantly higher than that in the general population[984.23(248.43-1902.61)ng/mL vs.219.01(97.26-821.92)ng/mL,P<0.01].Serum COMP levels were positively correlated with CAC(r=0.313,P=0.021)and serum parathyroid hormone in MHD patients(r=0.359,P<0.01).Linear regression suggested that after adjusting for age,fasting blood glucose(Glu)and glycosylated hemoglobin(HbAlc),CAC score was an independent predictor in the final model for COMP level(β=0.424,t=3.130,P<0.01).The receiver operating characteristic(ROC)curve showed that COMP≥994 mg/mL had 68.0%sensitivity and 72.4%specificity for the prediction of severe CAC[area under the curve(AUC):0.674,P=0.030,95%CI:0.526-0.882].After a median follow-up of 16 months(8-24 months),there was no difference in the incidence rate of MACEs between the upper,middle and lower serum COMP groups.Conclusions Our study found that MHD patien

关键词： Biomarker Cartilage oligomeric matrix protein Coronary artery calcification Maintenance hemodialysis