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Science China Chemistry 2020年第6期63卷 850-859页

作者： yu mao P.Hu School of Chemistry and Chemical Engineering The Queen’s University of BelfastBelfastUK

To make methane a suitable energy carrier and transport less costly,it is an urgent and challenging task for us to convert methane to liquid under mild conditions *** this study,we explored partial methane oxidation to methanol by density functional theory(DFT)calculations using a hybrid functional(HSE06)with van der Waals(vdW)*** stabilities of different active sites over SSZ-13 and SAPO-34,two CHA type zeolites,are thoroughly investigated by ab initio molecular dynamics(AIMD)simulations and ab initio thermodynamics *** possible active sites,namely[CuOHCu]2+,[Cu(OH)2Cu]2+,[CuOCu]2+and[CuOH]+,are identified ***-to-methanol reaction mechanisms are further studied upon these most stable active sites,among which[CuOCu]2+and[CuOH]+are proved to be *** migration of species among zeolite pores are also discussed,which accounts for the activity on[CuOH]+*** concept may represent a more complete picture of catalytic reactions over zeolites in general.

关键词： DFT heterogeneous catalysis methane-to-methanol CHA zeolites

The toxicological effect of dietary excess of saccharicterpenin,the extract of camellia seed meal,in piglets

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Journal of Integrative Agriculture 2020年第1期19卷 211-224页

作者： WANG Man yu Bing HE Jun yu Jie LUO yu-heng LUO Jun-qiu mao xiang-bin CHEN Dai-wen Key Laboratory of Animal Disease-Resistance Nutrition Animal Nutrition InstituteSichuan Agricultural University

Recently, saccharicterpenin extracted from Camellia oleifera seed meal has become a widely used feed supplement in animal husbandry. In order to assess its safety, this study was designed to investigate the toxicity and histopathological effects of saccharicterpenin on piglets. One hundred-fifty weaned pigs((Yorkshire×Landrace)×Duroc), 75 males and 75 females with body weight(BW) of(7.35±0.29) kg, were randomly allotted to groups receiving diets supplemented with 0, 500, 1 000, 2 500 or 5 000 mg kg^–1 saccharicterpenin for 70 d. The diet with 500 mg kg^–1 saccharicterpenin supplementation improved liver glutathione peroxidase(GSH-Px) activity, and the diet with 1 000 mg kg^–1 saccharicterpenin supplementation improved liver glutathione S-transferase(GSH-S) activity in piglets on d 70(P<0.05). At 2 500 mg kg^–1, saccharicterpenin in the diets reduced average daily feed intake(ADFI) and average daily gain(ADG) of piglets from d 1 to 35, damaged the cardiac tissue and liver on d 35, and decreased white blood cell counts(WBC), activities of catalase(CAT) and GSH-Px, and concentrations of glucose(GLU) and urea nitrogen(BUN) in the blood of piglets on d 70(P<0.05). In addition, diets with 5 000 mg kg^–1 saccharicterpenin supplementation reduced ADFI, ADG and increased diarrhea rates of piglets from d 36 to 70, and decreased hemoglobin(HGB) concentration and activity of CAT in the blood of piglets on d 70(P<0.05). Moreover, at a rate of 5 000 mg kg^–1, saccharicterpenin supplementation increased pancreas index on d 35 and hepatic index on d 70, and damaged cardiac tissue, liver and spleen during the whole experimental period(P<0.05). These results suggested that dietary 500 mg kg^–1 saccharicterpenin supplementation had beneficial effects on piglets, but excessive supplementation(2 500 or 5 000 mg kg^–1) of saccharicterpenin in the diets could lead to growth retardation, hematological abnormalities and organ injuries.

关键词： growth retardation hematology organ injury piglets saccharicterpenin

Polyconchoecia commixtus gen. et sp. nov. (Ostracoda： Myodocopa： Halocyprididae) from the South China Sea

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Acta Oceanologica Sinica 2018年第10期37卷 70-78页

作者： DU Feiyan xiang Peng CHEN Ruixiang WANG Lianggen WANG yu WANG Chunguang LIN mao South China Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Guangzhou 510300 China Guangdong Province Key Laboratory of Fishery Ecology and Environment Guangzhou 510300 China Laboratory of Marine Biology and Ecology Third Institute of Oceanography State Oceanic Administration Xiamen 361005 China Collaborative Innovation Center of Deep Sea Biology Hangzhou 310012 China

Planktonic ostracods are small crustaceans abundant in marine ecosystem worldwide as appreciable part of marine zooplankton. Family Halocyprididae is a large group of halocyprid ostracods, and the tribe Conchoeciini has contained 21 genera previously. We described a further genus with a species Polyconchoecia commixtus gen. et sp. nov. from the middle of South China Sea in this study. The new species can be distinguished from related genera and species in having a unique combination of these characteristics： a lateral gland placed over right asymmetric gland and open near posterior margin; dense edge glands placed along ventral margin of carapace in line; shape of frontal organ; e-seta of first antenna is bare; endopod of second antenna has one small oval hump with central concave on mid-ventral margin, instead of processus mamillaris, exopod 1 has a small disto-dorsal spine, exopod 1 and 2 are fused, exopod 3 and 4 are bare; endopod 1 of mandible has one long ventral seta, endopod 2 has one ventral seta; maxillary endopod 1 has two basal setae; endopod 1 of fifth limb has only one ventral seta; endopod 1 of sixth limb and endopod 2 have no ventral seta. The definite distinctions in locations of major glands are the key characteristics of the new genus.

关键词： taxonomy Ostracoda tribe Conchoeciini Polyconchoecia commixtus gen. et sp. nov. South China Sea

Community structure and spatial-temporal variation of netzphytoplankton in the Bering Sea in summer

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Acta Oceanologica Sinica 2016年第4期35卷 99-107页

作者： WANG yu xiang Peng YE Youyin LIN Gengming YANG Qingliang LIN Heshan LIN mao Laboratory of Marine Biology and Ecology Third Institute of OceanographyState Oceanic Administration

Marine biodiversity is changing in response to altered physical environment, subsequent ecological changes as well as anthropogenic disturbances. In this study, phytoplankton samples in situ collected in the Bering Sea in July of 1999 and 2010 were analyzed to obtain phytoplankton community structure and spatial-temporal variation between the beginning and end of this decade, and the correlation of phytoplankton community dynamics and environmental factors was investigated. A total of 5 divisions, 58 genera and 153 species of phytoplankton belonging to 3 ecological groups were identified. The vast majority of phytoplankton consisted of diatoms accounting for 66.7% of the total species and 95.2% of the total abundance. Considering differentiation in spatial extent and phytoplankton sample types, there were subtle changes in species composition, large altering in abundance and significant variation in spatial distribution between two surveys. The abundance peak area was located at the Bering Strait while sub peak was found at the Bering Sea Basin. The boreal-temperate diatom was the dominant flora, which was subsequently replaced by eurythermal and frigid-water diatom. Phytoplankton community in the Bering Sea was not a simplex uniform community but composed of deep-ocean assemblage and neritic assemblage. The deep-ocean assemblage was located in the northwestern Pacific Ocean and Bering Sea Basin, dominated by boreal-temperate species（Neodenticula seminae, Thalassiothrix longissima, Amphiprora hyperborean, Chaetoceros atlanticus, Thalassiosira trifulta, etc.） and eurychoric species（Thalassionema nitzschioides, Ch. compressus, Rhizosolenia styliformis, etc.）, and characterized by low abundance, even interspecies abundance allocations, diverse dominant species and high species diversity. The neritic assemblage was distributed on the continental shelf and slope of Bering Sea and was mainly composed of frigid-water species（***？ldii, Ch. furcellatus, Ch. socialis

关键词： Bering Sea phytoplankton community structure spatial and temporal variation distribution environment changes

Protein tyrosine phosphatase 1B inhibitory activities of ursane-type triterpenes from Chinese raspberry, fruits of Rubus chingii

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Chinese Journal of Natural Medicines 2019年第1期17卷 15-21页

作者： ZHANG xiang-yu LI Wei WANG Jian LI Ning CHENG mao-Sheng KOIKE Kazuo Key Laboratory of Structure-Based Drug Design&Discovery Ministry of EducationShenyang Pharmaceutical University School of Pharmaceutical Engineering Shenyang Pharmaceutical University Faculty of Pharmaceutical Sciences Toho University

Protein tyrosine phosphatase 1 B(PTP1 B) has led to an intense interest in developing its inhibitors as anti-diabetes, anti-obesity and anti-cancer agents. The fruits of Rubus chingii(Chinese raspberry) were used as a kind of dietary traditional Chinese medicine. The methanolic extract of R. chingii fruits exhibited significant PTP1 B inhibitory activity. Further bioactivity-guided fractionation resulted in the isolation of three PTP1 B inhibitory ursane-type triterpenes: ursolic acid(1), 2-oxopomolic acid(2), and 2α, 19α-dihydroxy-3-oxo-urs-12-en-28-oic acid(3). Kinetics analyses revealed that 1 was a non-competitive PTP1 B inhibitor, and 2 and 3 were mixed type PTP1 B inhibitors. Compounds 1-3 and structurally related triterpenes(4-8) were further analyzed the structure-activity relationship, and were evaluated the inhibitory selectivity against four homologous protein tyrosine phosphatases(TCPTP, VHR, SHP-1 and SHP-2). Molecular docking simulations were also carried out, and the result indicated that 1, 3-acetoxyurs-12-ene-28-oic acid(5), and pomolic acid-3β-acetate(6) bound at the allosteric site including α3, α6, and α7 helix of PTP1 B.

关键词： Protein tyrosine phosphatase 1B Raspberry Rubus chingii Triterpene Ursane

Cloning and Characterization of Genes Coding for Fructan Biosynthesis Enzymes (FBEs) in Triticeae Plants

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Agricultural Sciences in China 2010年第3期9卷 313-324页

作者： GAO xiang SHE mao-yun YIN Gui-xiang yu Yang QIAO Wei-hua DU Li-pu YE Xing-guo National Key Facility of Crop Gene Resources and Genetic Improvement Key Laboratory of Crop Genetics and Breeding Ministry of Agriculture/Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China Biotechnology Research Institute Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China

Fructan is not only a carbon source for storage but also plays an important role as anti-stress agents in many plant species. Complex fructans having both β-（2,1）- and β-（2,6）-linked fructosyl units accumulate in Triticeae plants commonly. Three enzymes （sucrose： sucrose 1-fructosyltransferase, 1-SST, EC： 2.***.1.99; sucrose： fructan 6-fructosyltransferase, 6- SFT, EC： 2.***.1.10; and fructan： fructan 1-fructosyltransferase, 1-FFT, EC： 2.***.1.100） were involved in fructan biosynthesis in Triticeae plant species. We successfully isolated these genes from tetraploid wheat （Triticum turgidum, genotype： AABB）, common wheat （Triticum aestivum L., genotype： AABBDD） and three wild relatives of common wheat, Triticum urartu Thum. （the origin of the AA genome）, Aegilops speltoides （Tausch） Gren. （the putative source of the SS genome） and Aegilops tauschii Coss. （the source of the DD genome）. Sequence analysis revealed that all the FBEs （fructan biosynthetic enzymes） had three highly conserved functional motifs except 1-SST （EU981912） from tetraploid wheat species only with conserved DPNG. Low pI （isoelectric point） and potential N-glycosylation sites were predicted, which were crucial for protein compartmentation and post-translational process. Analysis on subcelluar localization signals showed that only 6-SFT had vacuolar-directed signal. Sequences alignment result showed that 1-SST and 1-FFT were more conservative and had closer relationship each other, while 6-SFT was more active during the evolution processing. According to the syntenic relationship between wheat and rice genome, FBEs were predicated to be located on the homeologous group 6 and group 2 chromosomes. Expression profile confirmed that expression of all the three FBEs were drought-stress induced. This study can assist to establish a useful theoretical platform for cold- or drought-tolerant improvement of wheat by modulating FBEs expression.

关键词： fructans fructan biosynthesis enzymes gene structure wheat evolution

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-yu Tang Chun-mao yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词：

同方期刊数据库

Single-source-precursor synthesis of porous W-containing SiC-based nanocomposites as hydrogen evolution reaction electrocatalysts

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Journal of Advanced Ceramics 2021年第6期10卷 1338-1349页

作者： Zhaoju yu Kangwei mao Yao FENG College of Materials Key Laboratory of High Performance Ceramic Fibers(Xiamen University)Ministry of EducationXiamen 361005China Technische Universitat Darmstadt Institut fur MaterialwissenschaftOtto-Berndt-Strafie 3D-64287DarmstadtGermany College of Materials Science and Engineering Changsha University of Science&TechnologyChangsha 410114China

In this paper,W-containing SiC-based ceramic nanocomposites were successfully prepared by a polymer-derived ceramic approach using allylhydridopolycarbosilane(AHPCS)as a SiC source,WC16 as a tungsten source,polystyrene(PS)as a pore forming agent as well as divinyl benzene(DVB)as a carbon rich ***-temperature phase behavior of the W-containing SiC-based ceramics after heat treatment was studied,showing that excessive DVB content in the feed will inhibit the crystallinity of W-containing nanoparticles in the final ceramic *** high specific surface area(SSA)of 169.4-276.9 m^(2)/g can be maintained even at high temperature in the range of 1400-1500℃,due to the carbothermal reaction which usually occurs between 1300 and 1400℃.All prepared W-containing SiC-based nanocomposites reveal electrocatalytic activity for the hydrogen evolution reaction(HER).In detail,compared with reversible hydrogen electrode(RHE),the ceramic sample PWA-2-1300 after heat treatment at 1300℃ has the smallest overpotential of 286 mV when the current density is 10 mA·cm^(-2) in acid medium,indicating the promising perspective in the water splitting field.

关键词： single-source-precursor W-containing phase SiC-based nanocomposites electrocatalyst hydrogen evolution reaction

Prioritizing chemicals for environmental management in China based on screening of potential risks

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Frontiers of Earth Science 2014年第1期8卷 104-114页

作者： xiangyi yu Yan mao Chemical Registration Center of Ministry of Environmental Protection Beijing 100012 China

The rapid development of China＇s chemical industry has created increasing pressure to improve the environmental management of chemicals. To bridge the large gap between the use and safe management of chemicals, we performed a comprehensive review of the international methods used to prioritize chemicals for environmental management. By comparing domestic and foreign methods, we confirmed the presence of this gap and identified potential solutions. Based on our literature review, we developed an appropriate screening method that accounts for the unique characteristics of chemical use within China. The proposed method is based on an evaluation using nine indices of the potential hazard posed by a chemical： three environmental hazard indices （persistence, bioaccumulation, and eco-toxicity）, four health hazard indices （acute toxicity, carcinogenicity, mutagenicity, and reproductive and developmental toxi- city）, and two environmental exposure hazard indices （chemical amount and utilization pattern）. The results of our screening agree with results of previous efforts from around the world, confirming the validity of the new system. The classification method will help decision- makers to prioritize and identify the chemicals with the highest environmental risk, thereby providing a basis for improving chemical management in China.

关键词： chemicals screening risk environmental management priority definition

First Passage Density of Brownian Motion with Two-sided Piecewise Linear Boundaries

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1505-1520页

作者： Zhen yu mao Zai TIAN Center for Applied Statistics School of StatisticsRenmin University of ChinaBeijing 100872P.R.China School of Mathematics and Data Science Changji UniversityChangji 831100P.R.China

The first passage time has many applications in fields like finance,econometrics,statistics,and ***,explicit formulas for the first passage density have only been obtained for a few *** paper derives an explicit formula for the first passage density of Brownian motion with twosided piecewise continuous boundaries which may have some points of *** are used to obtain a simplified formula for estimating the first passage ***,the results are also generalized to the case of two-sided general nonlinear *** can be easily carried out with Monte Carlo method and it is demonstrated for several typical two-sided boundaries that the proposed approximation method offers a highly accurate approximation of first passage density.

关键词： Boundary non-crossing probability first density passage density two-sided piecewise continuous boundaries Brownian motion