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Classification,biosynthesis,and biological functions of triterpene esters in plants

Plant Communications 2024年第4期5卷 67-93页

作者： Jia Liu Xue Yin chengxi kou Ramesha Thimmappa Xin Hua Zheyong Xue Key Laboratory of Saline-alkali Vegetation Ecology Restoration(Northeast Forestry University) Ministry of EducationHarbin 150040China Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization Northeast Forestry UniversityHarbin 150040China Amity Institute of Genome Engineering Amity UniversityNoidaUP India 201313India State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs Beijing 100700P.R.China

Triterpene esters comprise a class of secondary metabolites that are synthesized by decorating triterpene skeletons with a series of oxidation,glycosylation,and acylation *** triterpene esters with important bioactivities have been isolated and identified,including those with applications in the pesticide,pharmaceutical,and cosmetic *** also play essential roles in plant defense against pests,dis-eases,physical damage(as part of the cuticle),and regulation of root ***,there has been no recent summary of the biosynthetic pathways and biological functions of plant triterpene ***,we classify triterpene esters intofive categories based on their skeletons andfind that C-3 oxidation may have a significant effect on triterpenoid *** acid and aromatic moieties are common li-gands present in triterpene *** further analyze triterpene ester synthesis-related acyltransferases(TEsACTs)in the triterpene biosynthetic *** an evolutionary classification of BAHD acyltrans-ferases(BAHD-ATs)and serine carboxypeptidase-like acyltransferases(SCPL-ATs)in Arabidopsis thaliana and Oryza sativa,we classify 18 TEsACTs with identified functions from 11 *** the triterpene-skel-eton-related TEsACTs belong to BAHD-AT clades IIIa and I,and the only identified TEsACT from the SCPL-AT family belongs to the CP-I *** comprehensive review of the biosynthetic pathways and bioactivities of triterpene esters provides a foundation for further study of their bioactivities and applica-tions in industry,agricultural production,and human health.

关键词： triterpene esters acyltransferases classification biosynthesis biological functions

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Efficient heterologous biosynthesis of verazine,a metabolic precursor of the anti-cancer drug cyclopamine,in Nicotiana benthamiana

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Plant Communications 2024年第6期5卷 1-4页

作者： chengxi kou Jingling Liu Xue Yin Di He Jia Liu Xin Hua Rui Ma Wei Sun Zheyong Xue Pengda Ma College of Life Sciences Northwest A&F UniversityYangling 712100China Key Laboratory of Saline-alkali Vegetation Ecology Restoration(Northeast Forestry University) Ministry of EducationHarbin 150040China Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization Northeast Forestry UniversityHarbin 150040China Jilin Provincial Key Laboratory of Agricultural Biotechnology Jilin Academy of Agricultural SciencesChangchun 130033China Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine Institute of Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijing 100700China

Dear Editor,Among the large number of Veratrum steroid alkaloids(Zhang et al.,2020),cyclopamine has been shown to have various inhibitory mechanisms against cancer,including inhibition of the hedgehog signaling pathway,improvement of tumor tissue microenvironment,inhibition of cell respiration,promotion of cell apoptosis,and reversal of tumor drug resistance(Liu et al.,2023).The biosynthetic pathway of verazine,a possible metabolic precursor of cyclopamine,has been discovered in Veratrum californicum(Augustin et al.,2015).However,the content of Veratrum steroid alkaloids in plants is very low(Supplemental Figure 2),so reliance on direct extraction from plants for commercial production is not feasible.A more effective strategy is to synthesize rare plant secondary metabolites using synthetic biology technology(Liu et al.,2022).

关键词： cyclopamine cancer

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FK506 contributes to peripheral nerve regeneration by inhibiting neuroinflammatory responses and promoting neuron survival

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Neural Regeneration Research 2025年第7期20卷 2108-2115页

作者： Yuhui kou Zongxue Jin Yusong Yuan Bo Ma Wenyong Xie Na Han Department of Trauma and Orthopedics Peking University People’s HospitalBeijingChina National Center for Trauma Medicine Peking University People’s HospitalBeijingChina Key Laboratory of Trauma and Neural Regeneration(Peking University) Ministry of EducationBeijingChina Trauma Medicine Center Peking University People’s HospitalBeijingChina Department of Orthopedics China-Japan Friendship HospitalBeijingChina

FK506(Tacrolimus)is a systemic immunosuppressant approved by the *** and Drug ***506 has been shown to promote peripheral nerve regeneration,however,its precise mechanism of action and its pathways remain *** this study,we established a rat model of sciatic nerve injury and found that FK506 improved the morphology of the injured sciatic nerve,increased the numbers of motor and sensory neurons,reduced inflammatory responses,markedly improved the conduction function of the injured nerve,and promoted motor function *** findings suggest that FK506 promotes peripheral nerve structure recovery and functional regeneration by reducing the intensity of inflammation after neuronal injury and increasing the number of surviving neurons.

关键词： FK506 inflammation motor neurons nerve regeneration neuron peripheral nerve injury sensory neurons

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16.48% Efficient solution-processed CIGS solar cells with crystal growth and defects engineering enabled by Ag doping strategy

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Journal of Energy Chemistry 2025年第1期100卷 59-65页

作者： Mengyu Xu Shaocong Yan Ting Liang Jia Jia Shengjie Yuan Dongxing kou Zhengji Zhou Wenhui Zhou Yafang Qi Yuena Meng Litao Han Sixin Wu Key Laboratory for Special Functional Materials of MOE National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology School of Nanoscience and Materials Engineering Henan University

Solution-processed Cu（In,Ga）Se2（CIGS） solar cells suffer from serious carrier recombination and power conversion efficiency（PCE） loss because of the poor film properties and easy formation of ***, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage（VOC） of 662 m V and fill factor（FF） of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.

关键词： CIGS solar cells Solution-processed method Ag doping Crystal growth Defects engineering

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Cascade degradation and electrocatalytic upcycling of waste poly(ethylene terephthalate)to valued products

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Nano Research 2025年第1期18卷 76-93页

作者： Xin Li Zirui Jiang Zongkui kou John Wang Shiyou Zheng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Department of Materials Science and Engineering National University of SingaporeSingapore 117574Singapore

The global annual production of poly(ethylene terephthalate)(PET)has reached 82 million tons,yet only a small fraction(less than 20%)is *** ultra-slow degradation rate of PET results in the accumulation of PET waste in the environment,causing serious plastic pollution and posing severe challenges to *** response,great efforts have been directed toward developing a cascade degradation and electrocatalytic upcycling strategy,which serves as a“waste-towealth”*** strategy involves electro-reforming PEThydrolyzed intermediates or using PET pyrolyzed products as electrocatalysts to generate high-value *** review provides an overview of the state-of-the-art strategies for the“degradation-electrocatalytic upcycling(De-eUp)”of PET ***,an introduction to the strategy is provided,categorizing it into two main frameworks:“pyrolysis-electrocatalytic upcycling”and“hydrolysis-electrocatalytic upcycling”.The section on“pyrolysis-electrocatalytic upcycling”delves into the degradation methods for designing derived carbon nanomaterials and their utilization as high-performance ***“hydrolysis-electrocatalytic upcycling”section discusses recent advancements in electro-reforming of PET hydrolyzed intermediates for the production of C_(1) and C_(2) *** review concludes by examining the challenges and future prospects in developing an efficient and economical PET upcycling *** is anticipated that this review will stimulate further progress in plastic waste valorization.

关键词： poly(ethylene terephthalate)waste electrocatalytic upcycling pyrolysis hydrolysis ethylene glycol oxidation reaction

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Research on Key Technologies of Network Security Situational Awareness for Attack Tracking Prediction

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Chinese Journal of Electronics 2019年第1期28卷 162-171页

作者： kou Guang WANG Shuo TANG Guangming Artificial Intelligence Research Center National Innovation Institute of Defense Technology Information Engineering University

This paper analyzed the existing network security situation evaluation methods and discovered that they cannot accurately reflect the features of large-scale,synergetic, multi-stage gradually shown by network attack behaviors. For this purpose, the association between attack intention and network configuration information was deep analyzed. Then a network security situation evaluation method based on attack intention recognition was proposed. Unlike traditional method, the evaluation method was based on intruder. This method firstly made causal analysis of attack event and discovered and simplified intrusion path to recognize every attack phases, then realized situation evaluation based on the attack phases. Lastly attack intention was recognized and next attack phase was forecasted based on achieved attack phases, combined with vulnerability and network connectivity. A simulation experiments for the proposed network security situation evaluation model is performed by network examples. The experimental results show that this method is more accurate on reflecting the truth of attack. And the method does not need training on the historical sequence, so the method is more effective on situation forecasting.

关键词： Multi-stage attack Situation evaluation Network security Intention recognition Causal analysis

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An improved nonlinear conjugate gradient method with an optimal property

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Science China Mathematics 2014年第3期57卷 635-648页

作者： kou CaiXia School of Science Beijing University of Posts and Telecommunications

Conjugate gradient methods have played a special role in solving large scale nonlinear problems. Recently, the author and Dai proposed an efficient nonlinear conjugate gradient method called CGOPT, through seeking the conjugate gradient direction closest to the direction of the scaled memoryless BFGS method. In this paper, we make use of two types of modified secant equations to improve CGOPT method. Under some assumptions, the improved methods are showed to be globally convergent. Numerical results are also reported.

关键词： nonlinear conjugate gradient CGOPT unconstrained optimization global convergence modified secant equation

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Quality Control of Recycled Aggregates Derived from Construction and Demolition Wastes

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四川大学学报（工程科学版） 2009年第3期41卷 248-257页

作者： POON Chi-sun kou Shi-cong Dept. of Civil and Structural Engineering the Hong Kong Polytechnic Univ. Hung Horn Kowloon Hong Kong

In 2007,over 24 million tons of Construction and Demolition(C&D) wastes were generated in Hong *** the local landfills will be saturated in about 6 years,it is important to find a viable way to reuse these waste materials as to alleviate the demand on public fill *** order to tackle the problem,the Hong Kong government has set up a temporary recycling facility in Hong Kong in 2002 for producing different sizes of recycled aggregate for use in various construction *** Hong Kong Polytechnic University has been studying the feasible use of recycled aggregates in Hong Kong for a number of years.A substantial amount of experimental results on the properties of recycled aggregates and the effect of recycled aggregates on the properties of concrete and other construction products(*** blocks and granular sub-base) has been *** this paper,the experience of Hong Kong in using recycled aggregates are summarized and a set of quality control guidelines proposed for governing the use of recycled aggregates in Hong Kong is *** experience and guidelines may also be useful for the recycling of waste materials derived from the recent Sichuan earthquake in China.

关键词：建筑物工程质量抗震设计建筑结构

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A Barzilai-Borwein conjugate gradient method

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Science China Mathematics 2016年第8期59卷 1511-1524页

作者： DAI YuHong kou CaiXia LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems Science Chinese Academy of Sciences School of Science Beijing University of Posts and Telecommunications

The linear conjugate gradient method is an optimal method for convex quadratic minimization due to the Krylov subspace minimization property. The proposition of limited-memory BFGS method and Barzilai-Borwein gradient method, however, heavily restricted the use of conjugate gradient method for largescale nonlinear optimization. This is, to the great extent, due to the requirement of a relatively exact line search at each iteration and the loss of conjugacy property of the search directions in various occasions. On the contrary, the limited-memory BFGS method and the Barzilai-Bowein gradient method share the so-called asymptotical one stepsize per line-search property, namely, the trial stepsize in the method will asymptotically be accepted by the line search when the iteration is close to the solution. This paper will focus on the analysis of the subspace minimization conjugate gradient method by Yuan and Stoer(1995). Specifically, if choosing the parameter in the method by combining the Barzilai-Borwein idea, we will be able to provide some efficient Barzilai-Borwein conjugate gradient(BBCG) methods. The initial numerical experiments show that one of the variants, BBCG3, is specially efficient among many others without line searches. This variant of the BBCG method might enjoy the asymptotical one stepsize per line-search property and become a strong candidate for large-scale nonlinear optimization.

关键词： conjugate gradient method subspace minimization Barzilai-Bowein gradient method line search descent property global convergence

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A practical iterative two-view metric reconstruction with uncalibrated cameras

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1614-1623页

作者： ZHOU Yong-jun kou Xin-jian School of Naval Architecture. Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

This paper presents a practical iterative algorithm for two-view metric reconstruction without any prior knowledge about the scene and motion in a nonsingular geometry configuration. The principal point is assumed to locate at the image center with zero skew and the same aspect ratio, and the interior parameters are fixed, so the self-calibration becomes focal-length cali- bration. Existing focal length calibration methods are direct solutions of a quadric composed of fundamental matrix, which are sensitive to noise. A quaternion-based linear iterative Least-Square Method is proposed in this paper, and one-dimensional searching for optimal focal length in a constrained region instead of solving optimization problems with inequality constraints is applied to simplify the computation complexity, then unique rotational matrix and translate vector are recovered. Experiments with simulation data and real images are given to verify the algorithm.

关键词： Close-range photogrammetry Computer vision General relative orientation Unit quaternion Metric reconstruction

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