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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

Prevalence of Brick Tea-type Fluorosis in Children Aged 8–12 Years in Qinghai Province,China

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Biomedical and Environmental Sciences 2021年第4期34卷 334-336页

作者： li qiang zhao zhi Jun Qinghai Institute for Endemic Disease Prevention and Control Xining 811602QinghaiChina

Fluorosis is a serious health problem,and an endemic disease in certain areas in China,India,and some countries in Africa[1].There are three types of fluorosis which includes drinking-water type fluorosis,coal-burning pollution type fluorosis,and brick tea-type ***-burning pollution type fluorosis and brick tea-type fluorosis are found only in China's Mainland mainland.

关键词： mainland pollution Fluorosis

Commwarrior worm propagation model for smart phone networks

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The Journal of China Universities of Posts and Telecommunications 2008年第2期15卷 60-66页

作者： XIA Wei li zhao-hui CHEN zeng-qiang YUAN Zhu-zhi College of Information Technical Science Nankai UniversityTianjin 300071 China

Commwarrior worm is capable of spreading through both Bluetooth and multimedia messaging service （MMS） in smart phone networks. According to the propagation characteristics of Bluetooth and MMS, we built the susceptibleexposed-infected-recovered-dormancy （SEIRD） model for the Bluetooth and MMS hybrid spread mode and performed the stability analysis. The simulation results show good correlation with our theoretical analysis and demonstrate the effectiveness of this dynamic propagation model. On the basis of the SEIRD model, we further discuss at length the influence of the propagation parameters such as user gather density in groups, moving velocity of smart phone, the time for worm to replicate itself, and other interrelated parameters on the propagation of the virus. On the basis of these analytical and simulation results, some feasible control strategies will be proposed to restrain the spread of mobile worm such as commwarrior on smart phone network.

关键词： smart phone virus spreading model Bluetooth,MMS

A curve-based material recognition method in MeV dual-energy X-ray imaging system

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Nuclear Science and Techniques 2016年第1期27卷 13-20页

作者： zhi-qiang Chen Tiao zhao liang li Department of Engineering Physics Tsinghua University Key Laboratory of Particle and Radiation Imaging (TsinghuaUniversity) Ministry of Education

High-energy dual-energy X-ray digital radiography imaging is mainly used in the material recognition of cargo inspection. We introduce the development history and principle of the technology and describe the data process flow of our system. The system corrects original data to get a dual-energy transparence image. Material categories of all points in the image are identified by the classification curve,which is related to the X-ray energy spectrum. For the calibration of classification curve, our strategy involves a basic curve calibration and a real-time correction devoted to enhancing the classification accuracy. Image segmentation and denoising methods are applied to smooth the image. The image contains more information after colorization. Some results show that our methods achieve the desired effect.

关键词： X射线成像系统校准曲线材料识别识别方法数据处理流程透明图像分类精度实时校正

linear Analysis of Longshore Currents Instability over Mild Slopes

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China Ocean Engineering 2018年第6期32卷 675-682页

作者： SHEN liang-duo ZOU zhi-li zhao Xi-zeng School of Port and Transportation Engineering Zhejiang Ocean University State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Ocean College Zhejiang University

Longshore current instability is important to nearshore hydrodynamic and sediment transport. This paper investigates the longshore current instability growth model based experimental data with different velocity profiles of slopes1:100 and 1:40 by adopting a linear shear instability model with the bottom friction effects. The results show that:(1)Only backshear mode exists in the instability of longshore current for slope 1:40 and frontshear and backshear modes may exist slope 1:100.(2) The peaks of linear instability growth mode for slope 1:100 correspond to three cases: the dominant peak is formed by the joint action of both frontshear and backshear, or by backshear alone without the existence of the smaller peak or formed by either the frontshear or backshear.(3) Bottom friction can decrease the corresponding unstable growth rate but it cannot change the unstable fluctuation period. The results of fluctuation period, wavelength and spatial variation obtained by the analysis of linear shear instability are in good agreement with experimental results.

关键词： influence of bottom friction linear shear instability longshore current instability growth mode instability mode linear instability instability

Use of Spent Mushroom Substrate as Growing Media for Tomato and Cucumber Seedlings

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Pedosphere 2012年第3期22卷 333-342页

作者： ZHANG Run-Hua DUAN zeng-qiang li zhi-Guo State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) Wuhan Vegetable Research Institute Wuhan 430065(China) Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074(China)

The aim of this research was to evaluate weathered spent mushroom substrate （SMS）, made from spent Flammulina velutipes mushroom substrate, as a growing medium for nursery seedlings. Two vegetable species, cucumber （Cucumis sativus L. cv. Jinchun No. 2） and tomato （Solanurn lycopersicum L. cv. Mandy）, were grown in 8 media of SMS in various ratios with perlite or vermiculite. A mixed substrate of peat with perlite （1：1; v：v） was used as the control （CK）. The experiment was arranged in a completely randomized design under greenhouse conditions. Prior to sowing, some physical and chemical properties of the growing media were determined. Results showed that all the mixtures had desirable physical and chemical properties for their use in nursery tomato and cucumber seedlings except for the T4 （SMS：vermiculite = 1：1; v：v） and the T8 （SMS：perlite = 2：1; v：v） mixtures. Compared with the CK, increased plant height, leaf area, fresh weight, dry weight and index of seedling quality were found in the T3 （SMS：vermiculite = 2：1; v：v） and T6 （SMS：perlite = 4：1; v：v） growing media. SMS should be considered as an alternative for the widely used but expensive and resource-limited peat in greenhouse cultivation.

关键词： mushroom substrnte nursery seedlings peat perlite vermiculite

Learning Sequential and Structural Dependencies Between Nucleotides for RNA N6-Methyladenosine Site Identification

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IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2123-2134页

作者： Guodong li Bowei zhao Xiaorui Su Dongxu li Yue Yang zhi zeng Lun Hu Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of ScienceUrumqi 830011China College of Computer Xi’an Jiaotong UniversityXi’an 710049China IEEE

N6-methyladenosine(m6A)is an important RNA methylation modification involved in regulating diverse biological processes across multiple ***,the identification of m6A modification sites provides valuable insight into the biological mechanisms of complex diseases at the post-transcriptional *** a variety of identification algorithms have been proposed recently,most of them capture the features of m6A modification sites by focusing on the sequential dependencies of nucleotides at different positions in RNA sequences,while ignoring the structural dependencies of nucleotides in their threedimensional *** overcome this issue,we propose a cross-species end-to-end deep learning model,namely CR-NSSD,which conduct a cross-domain representation learning process integrating nucleotide structural and sequential dependencies for RNA m6A site ***,CR-NSSD first obtains the pre-coded representations of RNA sequences by incorporating the position information into single-nucleotide states with chaos game representation *** then constructs a crossdomain reconstruction encoder to learn the sequential and structural dependencies between *** minimizing the reconstruction and binary cross-entropy losses,CR-NSSD is trained to complete the task of m6A site *** experiments have demonstrated the promising performance of CR-NSSD by comparing it with several state-of-the-art m6A identification ***,the results of cross-species prediction indicate that the integration of sequential and structural dependencies allows CR-NSSD to capture general features of m6A modification sites among different species,thus improving the accuracy of cross-species identification.

关键词： Cross-domain reconstruction cross-species prediction N6-methyladenosine(m6A)modification site RNA sequence sequential and structural dependencies

Analog rise-time discriminator for CdZnTe detector

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Nuclear Science and Techniques 2017年第4期28卷 59-65页

作者： Chuan-Hao Hu Guo-qiang zeng liang-Quan Ge Shi-Long Wei Jian Yang qiang li Hong-zhi li Chengdu University of Technology Chengdu 610059 China National Ocean Technology Center Tianjin 300112 China

Due to variable time for charge collection,energy resolution of nuclear detectors declines,especially compound semiconductor detectors like cadmium zinc telluride(CdZnTe) *** solve this problem,an analog rise-time discriminator based on charge comparison principle is *** reference charge signal after attenuation is compared with the deconvoluted and delayed current *** is found that the amplitude of delayed current signal is higher than that of the reference charge signal when rise time of the input signal is shorter than the discrimination time,thus generating gating signal and triggering DMCA(digital multi-channel analyzer) to receive the total integral charge *** rise time of the input signal is longer than discrimination time,DMCA remains inactivated and the corresponding total integral charge signal is *** results show that combination of the designed rise-time discriminator and DMCA can reduce hole tailing of CdZnTe detector *** resolution of the system is 0.98%@662 keV,and it is still excellent under high counting rates.

关键词： Analog rise-time discriminator CdZnTe detector Charge comparison principle

三七总皂苷调控破骨细胞外泌体中差异miRNA表达抑制成骨细胞铁死亡

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中国组织工程研究 2025年第19期29卷 4011-4021页

作者：陶红成曾平刘金富田照丁强李晁辉韦建杰李豪广西中医药大学广西壮族自治区南宁市530200 广西中医药大学第一附属医院广西壮族自治区南宁市530023 广西中医基础研究重点实验室广西壮族自治区南宁市530200

背景:激素性股骨头坏死多是由于长期大量使用激素所致,但具体的发病机制尚未明确,有待于进一步研究。目的:筛选出三七总皂苷干预破骨细胞来源外泌体中的差异miRNA,在此基础上构建成骨相关铁死亡调控网络,以探索激素性股骨头坏死发生的... 详细信息

背景:激素性股骨头坏死多是由于长期大量使用激素所致,但具体的发病机制尚未明确,有待于进一步研究。目的:筛选出三七总皂苷干预破骨细胞来源外泌体中的差异miRNA,在此基础上构建成骨相关铁死亡调控网络,以探索激素性股骨头坏死发生的潜在机制及研究方向。方法:MTT实验检测不同浓度地塞米松和不同质量浓度三七总皂苷对Raw264.7细胞系的毒性作用;抗酒石酸酸性磷酸酶染色和TUNEL染色检测三七总皂苷对破骨细胞抑制和凋亡的影响;从三七总皂苷干预的破骨细胞中提取外泌体,对外泌体进行测序找出差异表达miRNA,通过CytoScape 3.9.1构建并可视化差异表达的miRNA与mRNA间的调控网络;通过GO分析和KEGG分析筛选候选mRNA;最后筛选出铁死亡相关的差异基因,构建铁死亡相关基因的调控网络。结果与结论:①通过MTT实验确定了适合干预Raw264.7细胞的地塞米松浓度(0.1μmol/L)和三七总皂苷质量浓度(1736.85μg/mL);②三七总皂苷对破骨细胞有抑制作用并能促进其凋亡;③从破骨细胞来源外泌体样本中鉴定出20个差异miRNA,通过靶标mRNA预测出11种成骨相关的差异miRNA,并构建了4个上调的差异表达miRNA对应于155个下调的候选mRNA以及7个下调的差异表达miRNA对应于238个上调的候选mRNA的调控网络;④在差异基因中筛选出与铁死亡相关的基因24个,最终构建了12个网络(miR-98-5p/PTGS2,miR-23b-3p/PTGS2,miR-425-5p/TFRC,miR-133a-3p/TFRC,miR-185-5p/TFRC,miR-23b-3p/NFE2L2,miR-23b-3p/LAMP2,miR-98-5p/LAMP2,miR-182-5p/LAMP2,miR-182-5p/TLR4,miR-23b-3p/ZFP36,miR-182-5p/ZFP36)。这些结果表明三七总皂苷可能通过调控破骨细胞外泌体来源miRNA的表达来调节成骨细胞铁死亡,为激素性股骨头坏死的机制研究提供新的思路。

关键词：激素性股骨头坏死三七总皂苷破骨细胞外泌体铁死亡调控网络