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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1期68卷 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： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

Propagating subduction initiation of the Caroline Plate at the Mussau Trench

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Science China Earth Sciences 2025年第1期68卷 253-269页

作者： chun-Feng LI Yongkang DENG Tao WU Dongdong DONG Guoliang ZHANG Jiazheng ZHANG Yutao LIU Yaqing LI Fugui tang Lulu ZHANG Department of Marine Sciences Zhejiang University Laboratory of Marine Mineral Resources Laoshan Laboratory key Lab of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences key Lab of Ocean and Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Science & Technology on Integrated Information System Lab Institute of Software Chinese Academy of Sciences

New seismic imaging from the Mussau Trench confirms that, under horizontal compression on an oceanic plate boundary, it is within the young and weak oceanic plate that a trench will develop, and it is the young plate, not so long after its birth, that starts to subduct toward the old plate. The Mesozoic Pacific Plate cannot easily bend, under the joint horizontal compression and vertical gravity pull, even with a pre-existing weak zone in place and with a large age offset across the plate boundary. The bending of the Caroline Plate near the northern end of the Mussau Trench started only after a long-time span of trench migration, and/or after a prolonged transition from initial compression to trench development. Highly contrasting trench deformation and sedimentary accretion between two parallel seismic sections support an evident migration of underthrusting or significant longitudinal heterogeneity along the trench. The swift transition from underthrusting to non-thrusting can be explained by a counter-clockwise rotation of the Caroline Plate. That miniature accretionary wedges develop even before the subduction initiates imply strong compression and uplifting before the underthrusting can kick-start. Rotation of the Caroline Plate have been halted as the Mussau Trench is seismically rather quiet and the Lyra Trough to the east shows relaxational extension.

关键词： Mussau Trench Subduction initiation Seismic reflection Caroline Plate

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Extraction Separation of Germanium with Hydroxamic Acid HGS98

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Journal of Central South University 2000年第1期12卷 40-42页

作者： tang Shu-fang zhou chun-shan JIANG Xin-yu ZHAO chun-lei College of Chemistry and Chemical Engineering Central South University of TechnologyChangsha 410083China

The extraction separation of germanium from indium raffinate in hydrometallurgical zinc process was discussed. The conditions and mechanism of the extraction with hydroxamic acid HGS98 have been investigated in detail. The results show that u sing 2% (mass fraction) hydroxamic acid HGS98 and 5% D 2EHPA as synergist, germanium is extracted (1 stage) over 99% in 5 min at phase ratio ( V o∶ V a) of 1∶5 from indium raffinate with original acidity. Then, using 2 mol·L -1 NH 4F as strip liquor, the stripping recovery is over 98% in 15 min at phase ratio of 1∶1. This process has the following advantages:easy to operate, high recovery and selectivity, and lower investment cost. It provides a new way to recover rare metal-germanium from metallurgical spent residues.

关键词： extraction separation germanium hydroxamic acid HGS98

Impedance Analysis Considering Unstable Subsystem Poles for MMC-HVDC-based Wind Farm Integration System

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CSEE Journal of Power and Energy Systems 2022年第2期8卷 634-639页

作者： ke Ji Hui Pang shan Liu Guangfu tang China Electric Power Research Institute Beijing100192China Global Energy Interconnection Research Institute Beijing 102211China

Employing the AC/DC impedance analysis method,extensive research has been conducted on issues pertaining to harmonic resonance observed in wind farm-connected MMCHVDC systems over the past 5 *** general,this method divides the studied system into two subsystems at AC and DC ***,the impedance produced by these subsystems can be used to determine the system stability by implementing Nyquist criterion or generalized Nyquist stability ***,the existing impedance analysis methods usually assume the subsystems to be stable and disregard certain special cases with potentially unstable subsystems,where the unstable poles of these subsystems must be evaluated before applying Nyquist *** view of this consideration,a simplified method for identifying unstable subsystem poles is presented in this ***,the shortcoming of existing impedance analyses is rectified by considering the unstable subsystem *** proposed method and the stability analyses are validated by the electromagnetic transient simulation performed in PSCAD/EMTDC.

关键词： AC/DC side impedance method harmonic resonance MMC-HVDC small-signal stability wind farm

Effect of strain,strain rate and temperature on workability of AZ80 wrought magnesium alloy

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中国有色金属学会会刊：英文版 2012年第S3期22卷 650-655页

作者： Lü wen-quan QUAN Guo-zheng YU chun-tang ZHAO Lei zhou Jie College of Materials Science and Engineering Chongqing University

The hot deformation behavior of AZ80 wrought magnesium alloy was studied in the temperature range of 523-673 K and the strain rate range of 0.01-10 s-1 using hot compression *** the flow stresses behavior,the processing maps were calculated and analyzed according to the dynamic materials *** stable,metastable and unstable regimes were *** optimum processing conditions were suggested as following:the DRX regions in Domain #1-0.25,Domain #2-0.25,Domain #1-0.45,Domain #2-0.45,Domain #3-0.45,Domain #1-0.65 and Domain #1-0.85,and the DRV regions in Domain #3-0.25 and Domain #*** each "safe" DRX domain,it is preferable to conduct hot working in the small region around efficiency peak *** strain has a great influence on the processing *** whole area of the "safe" domains increases with the increase of true strain from 0.25 to 0.65,while it decreases with the increase of true strain from 0.65 to *** results of kinetic analysis reveal that the values of apparent activation energy in all the domains are higher than that for self-diffusion in pure magnesium (135kJ/mol),and the deformation mechanism in all the domains is likely to be cross-slip.

关键词： AZ80 magnesium alloy strain rate kinetic analysis processing map flow behavior

A Brain-inspired SLAM System Based on ORB Features

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International Journal of Automation and computing 2017年第5期14卷 564-575页

作者： Sun-chun zhou Rui Yan Jia-Xin Li Ying-ke Chen Huajin tang Neuromorphic Computing Research Center College of Computer ScienceSichuan UniversityChengdu 610065China

This paper describes a brain-inspired simultaneous localization and mapping （SLAM） system using oriented features from accelerated segment test and rotated binary robust independent elementary （ORB） features of RGB （red, green, blue） sensor for a mobile robot. The core SLAM system, dubbed RatSLAM, can construct a cognitive map using information of raw odometry and visual scenes in the path traveled. Different from existing RatSLAM system which only uses a simple vector to represent features of visual image, in this paper, we employ an efficient and very fast descriptor method, called ORB, to extract features from RCB images. Experiments show that these features are suitable to recognize the sequences of familiar visual scenes. Thus, while loop closure errors are detected, the descriptive features will help to modify the pose estimation by driving loop closure and localization in a map correction algorithm. Efficiency and robustness of our method are also demonstrated by comparing with different visual processing algorithms.

关键词： Simultaneous localization and mapping (SLAM) RatSLAM mobile robot oriented features from accelerated segment test and rotated binary robust independent elementary (ORB) features of RGB (red green blue) cognitive map.

Excavation-induced microseismicity: microseismic monitoring and numerical simulation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第6期13卷 445-460页

作者： Nu-wen XU chun-an tang Hong LI Feng DAI ke MA Jing-dong SHAO Ji-chang WU State key Laboratory of Hydraulics and Mountain River Engineering College of Water Resources and Hydropower Siehuan UniversityChengdu 610065China Institute o fRock Instability and Seismicity Research Dalian University of TechnologyDalian 116024China HydroChina Chengdu Engineering Corporation Chengdu 610072China China Guodian Dadu River Dagangshan Hydropower Development Co. Ltd.Ya'an 625409China

The volume of influence of excavation at the right bank slope of Dagangshan Hydropower Station, southwest China, is essentially determined from microseismic monitoring, numerical modeling and conventional measurements as well as in situ observations. Microseismic monitoring is a new application technique for investigating microcrackings in rock slopes. A micro- seismic monitoring network has been systematically used to monitor rock masses unloading relaxation due to continuous exca- vation of rock slope and stress redistribution caused by dam impoundment later on, and to identify and delineate the potential slippage regions since May, 2010. An important database of seismic source locations is available. The analysis of microseismic events showed a particular tempo-spatial distribution. Seismic events predominantly occurred around the upstream slope of 1180 m elevation, especially focusing on the hanging wall of fault XL316-1. Such phenomenon was interpreted by numerical modeling using RFPA-SRM code （realistic failure process analysis-strength reduction method）. By comparing microseismic activity and results of numerical simulation with in site observation and conventional measurements results, a strong correlation can he obtained between seismic source locations and excavation-induced stress distribution in the working areas. The volume of influence of the rock slope is thus determined. Engineering practices show microseismic monitoring can accurately diagnose magnitude, intensity and associated tempo-spatial characteristics of tectonic activities such as faults and unloading zones. The integrated technique combining seismic monitoring with numerical modeling, as well as in site observation and conventional surveying, leads to a better understanding of the internal effect and relationship between microseismic activity and stress field in the right bank slope from different perspectives.

关键词： Microseismic monitoring Rock slope Numerical simulation Stability analysis Dagangshan Hydropower Station

Advances in Research on Genetically Engineered Plants for Metal Resistance

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Journal of Integrative Plant Biology 2006年第11期48卷 1257-1265页

作者： Ri-Qing Zhang chun-Fang tang Shi-Zhi wen Yun-Guo Liu ke-Lin Li College of Resource and Environment Central South Forestry University Changsha 410004 China College of Environmental Science and Engineering Hunan University Changsha 410082 China）

The engineering application of natural hyperaccumulators In removing or inactivating metal pollutants from soil and surface water In field trials mostly presents the insurmountable shortcoming of low efficiency owing to their little biomass and slow growth. Based on further understanding of the molecular mechanism of metal uptake, translocation, and also the separation, identification, and cloning of some related functional genes, this article highlights and summarizes In detail the advances in research on transgenlc techniques, such as Agrobacterlurn tumefaciens-medlated transformation and particle bombardment, in breeding of plants for metal resistance and accumulation, and points out that deepening the development of transgenlc plants Is one of the efficient approaches to improving phytoremedlatlon efficiency of metalcontaminated environments. From the viewpoint of sustainable development, governments should strengthen support to the development of genetic engineering for metal resistance and accumulation In plants.

关键词： accumulation genetically engineered metal plants resistance.

Kinetic Characteristics of Neutralizing Antibody Responses Vary among Patients with COVID-19

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Biomedical and Environmental Sciences 2021年第12期34卷 976-983页

作者： LI Ling Hua TU Hong Wei LIANG Dan wen chun Yan LI An An LIN Wei Yin HU ke Qi HONG wen shan LI Yue Ping SU Juan ZHAO San Tao LI Wei YUAN Run Yu zhou Ping Ping HU Feng Yu tang Xiao Ping ke Chang wen ke Bi Xia CAI Wei Ping Guangzhou Eighth People’s Hospital Guangzhou Medical UniversityGuangzhou 510060GuangdongChina Guangdong Provincial Center for Diseases Control and Prevention Guangzhou 511430GuangdongChina School of Public Health Southern Medical UniversityGuangzhou 510515GuangdongChina shantou University Medical College Shantou 515063GuangdongChina

Objective The coronavirus disease 2019(COVID-19) pandemic continues to present a major challenge to public health. Vaccine development requires an understanding of the kinetics of neutralizing antibody(NAb) responses to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods In total, 605 serum samples from 125 COVID-19 patients(from January 1 to March 14, 2020)varying in age, sex, severity of symptoms, and presence of underlying diseases were collected, and antibody titers were measured using a micro-neutralization assay with wild-type *** NAbs were detectable approximately 10 days post-onset(dpo) of symptoms and peaked at approximately 20 dpo. The NAb levels were slightly higher in young males and severe cases, while no significant difference was observed for the other classifications. In follow-up cases, the NAb titer had increased or stabilized in 18 cases, whereas it had decreased in 26 cases, and in one case NAbs were undetectable at the end of our observation. Although a decreasing trend in NAb titer was observed in many cases, the NAb level was generally still *** We demonstrated that NAb levels vary among all categories of COVID-19 patients. Longterm studies are needed to determine the longevity and protective efficiency of NAbs induced by SARS-CoV-2.

关键词： Sex Kinetics Neutralizing antibody SARS-CoV-2