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Regulation of the High-Affinity Nitrate Transport System in Wheat Roots by Exogenous Abscisic Acid and Glutamine

Journal of Integrative Plant Biology 2007年第12期49卷 1719-1725页

作者： chao cai Xue-Qiang Zhao Yong-Guan Zhu Bin Li Yi-Ping Tong Zhen-Sheng Li The State Key Laboratory of Plant Cell and Chromosome Engineenng Institute of Genetics and Developmental Biology the Chinese Academy of Sciences Beijing 100101 China Research Center for Eco-environmental Sciences the Chinese Academy of Sciences Beijing 100085 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

Nitrate is a major nitrogen （N） source for most crops. Nitrate uptake by root cells is a key step of nitrogen metabolism and has been widely studied at the physiological and molecular levels. Understanding how nitrate uptake is regulated will help us engineer crops with improved nitrate uptake efficiency. The present study investigated the regulation of the high-affinity nitrate transport system （HATS） by exogenous abscisic acid （ABA） and glutamine （Gin） in wheat （Triticum aestivum L.） roots. Wheat seedlings grown in nutrient solution containing 2 mmol/L nitrate as the only nitrogen source for 2weeks were deprived of N for 4d and were then transferred to nutrient solution containing 50 μmol/L ABA, and 1 mmol/L Gin in the presence or absence of 2 mmol/L nitrate for 0, 0.5, 1, 2, 4, and 8 h. Treated wheat plants were then divided into two groups. One group of plants was used to investigate the mRNA levels of the HATS components NRT2 and NAR2 genes in roots through semi-quantitative RT-PCR approach, and the other set of plants were used to measure high-affinity nitrate influx rates in a nutrient solution containing 0.2 mmol/L ^15N-labeled nitrate. The results showed that exogenous ABA induced the expression of the TaNRT2.1, TaNRT2.2, TaNRT2.3, TaNAR2.1, and TaNAR2.2 genes in roots when nitrate was not present in the nutrient solution, but did not further enhance the induction of these genes by nitrate. Glutamine, which has been shown to inhibit the expression of NRT2 genes when nitrate is present in the growth media, did not inhibit this induction. When Gin was supplied to a nitrate-free nutrient solution, the expression of these five genes in roots was induced. These results imply that the inhibition by Gin of NRT2 expression occurs only when nitrate is present in the growth media. Although exogenous ABA and Gin induced HATS genes in the roots of wheat, they did not induce nitrate influx.

关键词： abscisic acid glutamine high-affinity nitrate transport system nitrate influx Tnticum aestivum.

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Total Synthesis of Przewaquinone A

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Chinese Chemical Letters 1997年第3期8卷 205-206页

作者： Wen Hu DUAN Jun chao cai (Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 200031) Shanghai Institute of Materia Medica Chinese Academy of Sciences Shanghai 200031 China

Przewaquinone A, a natural orthoquinone was synthesized through several steps, the analytic data of the synthetic target compound was identical with that of przewaquinone A.

关键词： HRMS HNMR Total Synthesis of Przewaquinone A

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Transient Stability Analysis Based on the Sensitivity of Trajectory Length

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Wuhan University Journal of Natural Sciences 2009年第2期14卷 169-173页

作者： JIANG Ningqiang HUANG chao cai Weifeng School of Automation Nanjing University of Science and Technology Nanjing 210094 Jiangsu China

The length of the trajectory is proposed as a function for the employment of the sensitivity analysis method in power system transient stability analysis. Its sensitivity to the faultclearing time is about 10 times higher than that of the energy function or the distance function. The integrating time is reduced to less than 3 s while the accuracy is maintained. It can also be used to provide parameter limits. Simulations on the WSCC 4 machine system and the New England system verify the effectiveness of sensitivity of trajectory length in transient stability analysis.

关键词： power system transient stability sensitivity analysis

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Analysis of Transition Mechanism of Cubic Boron Nitride Single Crystals under High Pressure-High Temperature with Valence Electron Structure Calculation

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Chinese Physics Letters 2019年第1期36卷 10-13页

作者： Mei-Zhe Lv Bin Xu Li-chao cai Feng Jia Xing-Dong Yuan School of Materials Science and Engineering Shandong University School of Materials Science and Engineering Shandong Jianzhu University

The possibilities of hexagonal boron nitride(hBN) and lithium boron nitride(Li_3BN_2) transition into cubic boron nitride(cBN) under synthetic pressure 5.0 GPa and synthetic temperature 1700 K are analyzed with the use of the empirical electron theory of solids and molecules. The relative differences in electron density are calculated for dozens of bi-phase interfaces hBN/cBN, Li_3BN_2/cBN. These relative differences of hBN/cBN are in good agreement with the first order of approximation(<10%), while those of Li_3BN_2/cBN are much greater than 10%.This analysis suggests that Li_3BN_2 is impossible to be intermediate phase but is a catalyst and cBN should be directly transformed by hBN.

关键词： Transition Mechanism Cubic Boron Valence Electron Structure Calculation

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Characteristic Optimization Based on Combined Statistical Indicators and Random Forest Theory

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CSEE Journal of Power and Energy Systems 2024年第6期10卷 2657-2666页

作者： Qingzhen Liu chao cai Lei Wu Renwu Yan School of Electric Engineering and Automation Fuzhou UniversityFuzhou 350116China Quanzhou Electric Power Supply Company State Grid Fujian Electric Power CompanyQuanzhou 362000China Electrical and Computer Engineering Department Stevens Institute of TechnologyHobokenNJ07030USA Department of Power System Fujian University of TechnologyFuzhou 350116China

In order to effectively utilize the dielectric response characteristics of transformers to diagnose the insulation state,this paper proposes a two-level hybrid optimization method for analyzing time-domain dielectric response *** optimization algorithm is based on the combined statistical indicators(CSI)and random forest(RF)*** initial feature space set is formed with 23 time-domain *** the first-level stage,statistical indices correlation,distance,and information indicators are integrated to assess the synthesis score of the characteristics,while highly redundant and lowclass discrimination characteristics are eliminated from the initial space *** the second-level stage,the Random Forest based outside bagging data theory is introduced to evaluate the least important characteristics,and the characteristics with low importance indices are excluded to obtain the final optimal feature space *** proposed method is carried out on 82 sets of data from actual dielectric response tests on oil-paper insulation ***,the final optimal feature space set,along with several other data sets,is tested via different diagnosis *** results show that the optimal feature space set obtained via the proposed method outperforms other feature space sets in terms of better adaptability and diagnosis accuracy.

关键词： Feature space optimization integrated statistical indicators oil-paper insulation state random forest time domain characteristic two-level algorithm

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Orthogonally woven 3D nanofiber scaffolds promote rapid soft tissue regeneration by enhancing bidirectional cell migration

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Bioactive Materials 2024年第9期39卷 582-594页

作者： Jiayi Yuan Bingbing Sun Weixing Ma chao cai Zhenzhen Huang Peiyi Zhou Lei Yi Lubin Liu Shixuan Chen School of Pharmacy Jiangsu Ocean UniversityLianyungang222005China Zhejiang Engineering Research Center for Tissue Repair Materials Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiang325001China Department of Critical Care Medicine The Air Force Characteristic Medical CenterAir Force Medical UniversityBeijing100000China Chongqing Health Center for Women and Children Chongqing Obstetric and Gynecologic HospitalChongqingChina Department of Burn Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China

Repairing large-area soft tissue defects caused by traumas is a major surgical *** multifunctional scaffolds with suitable scalability and favorable cellular response is crucial for soft tissue *** this study,we developed an orthogonally woven three-dimensional(3D)nanofiber scaffold combining electrospinning,weaving,and modified gas-foaming *** developed orthogonally woven 3D nanofiber scaffold had a modular design and controlled fiber *** vitro,the orthogonally woven 3D nanofiber scaffold exhibited adjustable mechanical properties,good cell compatibility,and easy drug *** vivo,for one thing,the implantation of an orthogonally woven 3D nanofiber scaffold in a full abdominal wall defect model demonstrated that extensive granulation tissue formation with enough mechanical strength could promote recovery of abdominal wall defects while reducing intestinal *** result of diabetic wound repair experiments suggested that orthogonally woven 3D nanofiber scaffolds had a higher wound healing ratio,granulation tissue formation,collagen deposition,and *** together,this novel orthogonally woven 3D nanofiber scaffold may provide a promising and effective approach for optimal soft tissue regeneration.

关键词： Tissue regeneration Electrospinning 3D nanofiber scaffold Orthogonal weaving Cell migration

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Multifractal estimation of NMR T_(2) cut-off value in low-permeability rocks considering spectrum kurtosis: SMOTE-based oversampling integrated with machine learning

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Petroleum Science 2023年第6期20卷 3411-3427页

作者： Xiao-Jun Chen Rui-Xue Zhang Xiao-Bo Zhao Jun-Wei Yang Zhang-Jian Lan Cheng-Fei Luo Jian-chao cai MOE Key Laboratory of Tectonics and Petroleum Resources Wuhan430074HubeiChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchesterM139PLUK Jianghan Oilfied SINOPECQianjiang430063HubeiChina Hainan Branch of CNOOC Ltd Haikou570311HainanChina CNOOC EnerTech-Drilling&Production Co.CNOOC Central Laboratory(Zhanjiang) Zhanjiang524057GuangdongChina National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China

The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight 0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.

关键词： Nuclear magnetic resonance Low-permeability porous media T_(2)cut-off value Fractal and multifractal Data augmentation Machine learning

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Gene Structure and Expression of the High-affinity Nitrate Transport System in Rice Roots

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Journal of Integrative Plant Biology 2008年第4期50卷 443-451页

作者： chao cai Jun-Yi Wang Yong-Guan Zhu Qi-Rong Shen Bin Li Yi-Ping Tong Zhen-Sheng Li State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental Biology the Chinese Academy of Sciences Beijing 100101 China Research Center for Eco-environmental Sciences the Chinese Academy of Sciences Beijing 100085 China Graduated University the Chinese Academy of Sciences Beijing 100049 China College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing 210095 China

Rice has a preference for uptake of ammonium over nitrate and can use ammonium-N efficiently. Consequently, transporters mediating ammonium uptake have been extensively studied, but nitrate transporters have been largely ignored. Recently, some reports have shown that rice also has high capacity to acquire nitrate from growth medium, so understanding the nitrate transport system in rice roots is very important for improving N use efficiency in rice. The present study Identified four putative NRT2 and two putative NAR2 genes that encode components of the high-affinity nitrate transport system （HATS） in the rice （Oryza sativa L. subsp, japonica cv. Nipponbare） genome. OsNRT2.1 and OsNRT2.2 share an Identical coding region sequence, and their deduced proteins are closely related to those from mono-cotyledonous plants. The two NAR2 proteins are closely related to those from mono-cotyledonous plants as well. However, OsNRT2.3 and OsNRT2.4 are more closely related to Arabidopsis NRT2 proteins. Relative quantitative reverse trsnscription-polymerase chain reaction analysis showed that all of the six genes were rapidly upregulated and then downrsgulated in the roots of N-starved rice plants after they were re-supplied with 0.2 mM nitrate, but the response to nitrate differed among gene members. The results from phylogenetic tree, gene structure and expression analysis implied the divergent roles for the Individual members of the rice NRT2 and NAR2 families. High-affinity nitrate influx rates associated with nitrate induction in rice roots were investigated and were found to be regulated by external pH. Compared with the nitrate influx rates at pH 6.5, alkaline pH （pH 8.0） inhibited nitrate influx, and acidic pH （pH 5.0） enhanced the nitrate influx in 1 h nitrate induced roots, but did not significantly affect that in 4 to 8 h nitrate induced roots.

关键词： high-affinity nitrate transport system nitrate influx NRT2 NAR2 Oryza sativa.

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Adaptive genetic diversity of dominant species contributes to species co-existence and community assembly

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Plant Diversity 2022年第3期44卷 271-278页

作者： Qiao-Ming Li chao-Nan cai Wu-Mei Xu Min Cao Li-Qing Sha Lu-Xiang Lin Tian-Hua He CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla666303YunnanChina Center of Plant Ecology Core Botanical GardensChinese Academy of SciencesMengla666303YunnanChina School of Advanced Study Taizhou UniversityTaizhou318000ZhejiangChina Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation Taizhou UniversityTaizhou318000ZhejiangChina School of Energy and Environment Science Yunnan Normal UniversityKunming650500YunnanChina School of Molecular and Life Sciences Curtin UniversityPO Box U1987PerthWA6845Australia

The synthesis of evolutionary biology and community ecology aims to understand how genetic variation within one species can shape community properties and how the ecological properties of a community can drive the evolution of a species.A rarely explored aspect is whether the interaction of genetic variation and community properties depends on the species'ecological *** we investigated the interactions among environmental factors,species diversity,and the within-species genetic diversity of species with different ecological *** high-throughput DNA sequencing,we genotyped a canopydominant tree species,Parashorea chinensis,and an understory-abundant species,Pittosporopsis kerrii,from fifteen plots in Xishuangbanna tropical seasonal rainforest and estimated their adaptive,neutral and total genetic diversity;we also surveyed species diversity and assayed key soil *** equation modelling revealed that soil nitrogen availability created an opposing effect in species diversity and adaptive genetic diversity of the canopy-dominant *** increased adaptive genetic diversity of *** led to greater species diversity by promoting *** species diversity reduced the adaptive genetic diversity of the dominant understory species,***,which was promoted by the adaptive genetic diversity of the canopy-dominant ***,such relationships were absent when neutral genetic diversity or total genetic diversity were used in the *** results demonstrated the important ecological interaction between adaptive genetic diversity and species diversity,but the pattern of the interaction depends on the identity of the *** results highlight the significant ecological role of dominant species in competitive interactions and regulation of community structure.

关键词： Adaptive genetic diversity Community assembly Dominant species Species-genetic diversity correlation(SGDC) Species co-existence Structural equation modelling

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Bottleneck Analysis for Data Acquisition in High-Speed Network Traffic Monitoring

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China Communications 2014年第1期11卷 110-118页

作者： JIANG Wei TIAN Zhihong cai chao GONG Bei College of Computer Science Beijing University of Technology Beijing 100124 China School of Computer National University of Defense Technology Changsha 410073 China Key Laboratory of Information and Network Security Ministry of Public Security Shanghai 201204 China School of Computer Science and Technology Harbin Institute of Technology Harbin 150001 China

The increasing network throughput challenges the current network traffic monitor systems to have compatible high-performance data *** design of packet processing systems is guided by the requirements of high packet processing *** this paper,we depict an in-depth research on the related techniques and an implementation of a high-performance data acquisition *** the bottleneck analysis with the aid of queuing network model,several performance optimising methods,such as service rate increasing,queue removing and model simplification,are *** experiment results indicate that this approach is capable of reducing the CPU utilization ratio while improving the efficiency of data acquisition in high-speed networks.

关键词： data acquisition bottleneck ana- lysis queuing theory semi-polling

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