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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

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AAV-mediated expression of p65shRNA and bone morphogenetic protein 4 synergistically enhances chondrocyte regeneration

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中国组织工程研究 2025年第17期29卷 3537-3547页

作者： Yu Yangyi Song Zhuoyue Lian Qiang ding kang Li Guangheng Shenzhen Key Laboratory of Musculoskeletal Tissue Reconstruction and Function Restoration Division of Adult Joint Reconstruction and Sports MedicineDepartment of Orthopedic SurgeryShenzhen People’s Hospital(The Second Clinical Medical College Jinan UniversityThe First Affiliated HospitalSouthern University of Science and Technology)Shenzhen 518020Guangdong ProvinceChina Department of Orthopedics Zhengzhou Orthopedics HospitalZhengzhou 450000Henan ProvinceChina Department of Orthopedics Shenzhen Pingle Orthopedics HospitalShenzhen 518000Guangdong ProvinceChina

BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent ***,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory *** studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage ***:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis ***:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were *** efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into *** experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 *** were collected at 4,12,and 24 weeks *** staining,including safranin O and Alcian blue,was applied after collecting articular ***,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in *** AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis *** cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal *** either p65shRNA or BMP4

关键词： osteoarthritis adeno-associated virus bone morphogenetic protein 4 p65-short hairpin RNA gene therapy short hairpin RNA transforming growth factor-β1 extracellular matrix articular cartilage chondrocytes.

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Anti-Noise Performance of the FT Continuous Zoom Analysis Method for Discrete Spectrum

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Chinese Journal of Mechanical Engineering 2010年第6期23卷 774-779页

作者： LINHuibin ding kang XU Chuanyan School of Mechanical and Automotive Engineering South China University of Technology Guangzhou 510640 China Guangdong Key Lab for Automotive Engineering Guangzhou 510640 China

As a discrete spectrum correction method, the Fourier transform （FT） continuous zoom analysis method is widely used in vibration signal analysis, but little effort had been made on this method＇s anti-noise performance. It is widely believed that the analysis accuracy of the method can be substantially improved by increasing the zoom multiple, however, with the zoom multiple increases, the frequency estimation accuracy may decline sometimes in practices. Aiming at the problems above, this paper analyzes the sources of frequency estimation error when a harmonic signal mixed with and without noise is processed using the FT continuous zoom analysis. According to the characteristics that the local maximum of the zoom spectrum may be wrongly selected when the signal is corrupted with noise, the number of wrongly selected spectrum lines is deduced under different signal-to-noise ratio and local zoom multiple, and then the maximum frequency estimation error is given accordingly. The validity of the presented analysis is confirmed by simulations results. The frequency estimation accuracy of this method will not improve any more under the influence of noise, and there is a best zoom multiple, when the zoom multiple is larger than the best zoom multiple; the maximum frequency estimation error will fluctuate back and forth. The best zoom multiple curves under different signal-to-noise ratios given provide a theoretical basis for the choice of the appropriate zoom multiples of the FT continuous zoom analysis method in engineering applications.

关键词： spectrum spectrum correction zoom analysis anti-noise performance

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An algorithm for decomposing a polynomial system into normal ascending sets

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Science China Mathematics 2007年第10期50卷 1441-1450页

作者： ding-kang WANG Yan ZHANG Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

We present an algorithm to decompose a polynomial system into a finite set of normal ascending sets such that the set of the zeros of the polynomial system is the union of the sets of the regular zeros of the normal ascending sets. If the polynomial system is zero dimensional, the set of the zeros of the polynomials is the union of the sets of the zeros of the normal ascending sets.

关键词： zero decomposition, normal ascending set, polynomial system

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Target Deployment and Retrieval Using JIAOLONG Manned Submersible in the Depth of 6600 m in Mariana Trench

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China Ocean Engineering 2017年第5期31卷 618-623页

作者： GAO Xiang ding kang REN Yu-gang FU Wen-tao ding Zhong-jun ZHAO Sheng-ya LIU Bao-hua National Deep Sea Center Institute of Deep-Sea Science and Engineering Chinese Academy of Sciences

China＇s 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench from the depth of 5500 to 6700 m, to investigate the geological, biological and chemical characteristics in the hadal area. During the cruise, JIAOLONG deployed a gas-tight serial sampler to collect the water near the sea bottom regularly. Five days later, the sub located the sampler in another dive and retrieved it successfully from the same location, which is the first time that scientists and engineers finished the high accuracy in-situ deployment and retrieval using a manned submersible with Ultra-Short Base Line （USBL） positioning system at the depth more than 6600 m. In this task, we used not only the USBL system of the manned submersible but also a compound strategy, including five position marks, the sea floor terrain, the depth contour, and the heading of the sub. This paper introduces the compound strategy of the target deployment and retrieval with the practical diving experience of JIAOLONG, and provides a promising technique for other underwater vehicles such as manned submersible or Remote Operated Vehicle （ROV） under similar conditions.

关键词： target deployment and retrieval manned submersible USBL Mariana Trench

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In vitro differentiation of rabbit bone marrow mesenchymal stem cells into Schwann cells Induction effect of platelet-rich plasma

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Neural Regeneration Research 2010年第1期5卷 35-40页

作者： Changsuo Xia Changrong ding Yingzhen Wang kang Sun Cailong Zhang Shaoqi Tian Department of Orthopaedics Affiliated Hospital of Qingdao University Medical College Qingdao 266003 Shandong Province China

BACKGROUND： Bone marrow mesenchymal stem cells （BMSCs） differentiate into Schwann cells via specific inducers. However, the induction and culture procedures are complicated. Various growth factors have been used for induction and culture, and are likely affected by their environment. OBJECTIVE： To explore the differentiation feasibility of platelet-dch plasma-induced rabbit BMSCs, supplemented with various growth factors, into Schwann-like cells in vitro, and to examine the secretory function of Schwann-like cells. DESIGN, TIME AND SETTING： This comparison study was performed at the Experimental Animal Center, Affiliated Hospital of Qingdao University Medical College, China in October 2008. MATERIALS： Platelet-rich plasma and BMSCs were respectively obtained from the femoral vein and bone marrow of 2-month old New Zealand rabbits. The rabbit nerve growth factor ELISA kit and rabbit nerve growth factor PCR kit （Jingmei Biotech, China）, as well as anti-rabbit S-100 immunofluorescence staining kit （Boster, China） were used in the present study. METHODS： BMSCs at passage three were harvested and were induced by 1 mmol/L β-mercaptoethanol and Dulbecco＇s-modified eagle＇s medium complete medium containing 35 ng/mL retinoic acid and 10% fetal bovine serum for the combination induction group, followed by incubation in complete medium supplemented with platelet-rich plasma. BMSCs in the single induction group were induced by β-mercaptoethanol and retinoic acid, followed by incubation in L-DMEM complete medium. BMSCs in the control group were incubated in L-DMEM complete medium. MAIN OUTCOME MEASURES： Cell growth in each group was observed under an inverted microscope. Following induction, S-100 protein expression was identified by immunofluorescence staining. Nerve growth factor protein concentrations in BMSC supernatant were subsequently measured by ELISA. In addition, nerve growth factor mRNA expression in the BMSCs was determined by reverse transcription-polymerase chain

关键词： mesenchymal stem cells Schwann-like cells induction differentiation

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Electrochemical corrosion failure mechanism of M152 steel under a salt-spray environment

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International Journal of Minerals,Metallurgy and Materials 2015年第11期22卷 1183-1189页

作者： Pan Yi Kui Xiao kang-kang ding Xu Wang Li-dan Yan Cheng-liang Mao Chao-fang Dong Xiao-gang Li Corrosion and Protection Center University of Science and Technology Beijing Institute of Advanced Materials and Technology University of Science and Technology Beijing State Key Laboratory for Marine Corrosion and Protection Luoyang Ship Material Research Institute Ningbo Institute of Material Technology & Engineering Chinese Academy of Sciences

The corrosion failure mechanism of M152 was studied using the neutral salt-spray test to better understand the corrosion behavior of 1Cr12Ni3Mo2VN（M152）, provide a basis for the optimization of material selection, and prevent the occurrence of failure. Moreover, the mechanism was investigated using the mass loss method, polarization curves, electrochemical impedance spectroscopy（EIS）, stereology microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy（EDS）. The results show that M152 steel suffers severe corrosion, especially pitting corrosion, in a high-salt-spray environment. In the early stage of the experiment, the color of the corrosion products was mainly orange. The products then gradually evolved into a dense, brown substance, which coincided with a decrease of corrosion rate. Correspondingly, the EIS spectrum of M152 in the late test also exhibited three time constants and presented Warburg impedance at low frequencies.

关键词： heat-resistant steel electrochemical corrosion failure mechanism salt spray test

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Hormonal Regulation of Leaf Morphogenesis in Arabidopsis

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Journal of Integrative Plant Biology 2007年第1期49卷 75-80页

作者： Lin-Chuan Li ding-Ming kang Zhang-Liang Chen Li-Jia Qu National Laboratory for Protein Engineering and Plant Genetic Engineering Peking-Yale Joint Research Center for Plant Molecular Genetics and AgroBiotechnology College of Life Sciences Peking University Beijing 100871 China Key Laboratory of Crop Genomics and Genetic Improvement of Ministry of Agriculture/Key laboratory of Crop Genetic Improvement of Beijing City College of Agronomy and Biotechnology China Agricultural University Beijing 100094 China

Leaf morphogenesis is strictly controlled not only by intrinsic genetic factors, such as transcriptional factors, but also by environmental cues, such as light, water and pathogens. Nevertheless, the molecular mechanism of how leaf morphogenesis is regulated by genetic programs and environmental cues is far from clear. Numerous series of events demonstrate that plant hormones, mostly small and simple molecules, play crucial roles in plant growth and development, and in responses of plants to environmental cues such as light. With more and more genetics and molecular evidence obtained from the model plant Arabidopsis, several fundamental aspects of leaf morphogenesis including the initiation of leaf primordia, the determination of leaf axes, the regulation of cell division and expansion in leaves have been gradually unveiled. Among these phytohormones, auxin is found to be essential in the regulation of leaf morphogenesis.

关键词： auxin curly leaf hormonal regulation leaf morphogenesis leaf shape

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A long-term in situ calibration system for chemistry analysis of seawater

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第9期11卷 701-708页

作者： Chun-yang TAN Bo JIN kang ding William E. SEYFRIED Jr. Ying CHEN State Key Lab of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China Department of Geology and Geophysics University of Minnesota Minneapolis 55455 USA

An in situ calibration system is a versatile exploration instrument for electrochemical sensors investigating the biochemical properties of the marine environment. The purpose of this paper is to describe the design of an auto-calibrating system for electrochemical (pH) sensors, which permits two-point in situ calibration, suitable for long-term measurement in deep sea aqueous environments. Holding multiple sensors, the instrument is designed to perform long-term measurements and in situ calibrations at abyssal depth (up to 4000 m). The instrument is composed of a compact fluid control system which is pressure-equilibrated and designed for deep-sea operation. In situ calibration capability plays a key role in the quality and reproducibility of the data. This paper focuses on methods for extending the lifetime of the instrument, considering the fluidics design, mechanical design, and low-power consumption of the electronics controller. The instrument can last 46 d under normal operating conditions, fulfilling the need for long-term operation. Data concerning pH measured during the KNOX18RR cruise (Mid-Atlantic Ridge, July-August, 2008) illustrate the desirable properties of the instrument. Combined with different electrodes (pH, H2, H2S, etc.), it should be of great utility for the study of deep ocean environments, including water column and diffuse-flow hydrothermal fluids.

关键词： pH Long-term In situ calibration Flow control Low power

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Study on the influence of projectile on muzzle disturbance

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Defence Technology（防务技术） 2018年第5期14卷 570-577页

作者： Fei-fei Liu Yan-ming Song Hai-long Yu Wen-ding Lin Jie Zhang Zhi-hui Si Ming-kang ding Xiao-ting Rui China Weapon Industry Corporation NHIC Nanjing Research Institute Nanjing210000China China Weapon Industry Corporation NHIC Baotou014000China Institute of Launch Dynamics Nanjing University of Science&TechnologyNanjing210094China

In order to make an efficient analysis of muzzle disturbance influenced by projectile mass, mass eccentricity, dynamic unbalance, load deviation, and clearance between projectile and bore, the orthogonal test method is extended to analyze the launch dynamics. Taking a tank as the research object, the launch dynamics equations of a tank system are established. Based on the stochastic simulation principle, the tank launch dynamic simulation system is constructed and through the development of the orthogonal test method, the influence of projectile on muzzle disturbance is studied. The study results provided both theoretical foundation and simulation approaches for improving the firing dispersion of the tank.

关键词： Muzzle disturbance Orthogonal test Projectile-barrel coupling Firing dispersion

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