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Nitric Oxide Content in Wheat Leaves and Its Relation to Programmed Cell Death of Main Stem and Tillers Under Different Nitrogen Levels

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Journal of Integrative Agriculture 2013年第2期12卷 239-250页

作者： GUO Jun-xiang chen Er-ying YIN Yan-ping WANG Ping LI Yong chen xiao-guang WU guang-lei WANG Zhen-lin National Key Laboratory of Crop Biology Agronomy College Shandong Agricultural University Xuzhou Sweetpotato Research Center/Sweetpotato Research Institute Chinese Academy of Agricultural Sciences

Nitric oxide （NO） is a key signaling molecule in different physiological processes of plants, including programmed cell death （PCD）. PCD of tillers plays an important role in surviving which are major components of grain yield. PCD was triggered in wheat leaves of main stem and tillers by NO content under different nitrogen treatments. In wheat, NO could be synthesized endogenously by nitrate reductase （NR）. As an inducible enzyme, NR activity was closely related to substrate concentration. Therefore, different nitrogen levels would change NR activity and NO production. The objective of this study was to determine the effects of NR activity, NO production, and the correlation between them on different tillers growth, development, senescence, and kernel protein content under different nitrogen levels. Field-experiments were conducted in 2009-2011 growing seasons, using two wheat cultivars with different spike-types. Results showed that for main stem and primary tillers, NR activity and NO content reached high level at heading stage, while for secondary tiller, the level of NR activity was low, but NO content was high in the present research. The NO synthesis depending on NR activity in wheat leaves was significant in the early growing stage, but the NO synthesis weakened with the progress of growing period. NO was related to the senescence of wheat leaves, but PCD was more sensitive to marked changes of NO content than NO content itself. N application had marked influence on the aging process of primary tiller, while had little influence on that of main stem and secondary tiller. Moreover, N fertilizer application could increase spike rate and protein content of primary tiller by N fertilizer application.

关键词： wheat nitric oxide programmed cell death tiller

20(S)-20-O-Camptothecin β-Aminopropionate: Novel Synthesis and Antitumor Activity in vitro

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Chemical Research in Chinese Universities 2006年第6期22卷 727-731页

作者： LI Yu-yan YOU Qi-dong WANG Lei chen Sheng chen xiao-guang LI Yan LI Hong-yan Department of Medicinal Chemistry School of Pharmacy China Pharmaceutical University Nanjing 210009 P. R. China Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College eijing 100050 P.R. China

To improve the biological anticancer activity of 20 （S）-camptothecin, a novel class of 20 （S）-20-O-camptotheein β-aminopropionates were designed and synthesized with eamptothecins as the starting materials, through acylation with acryloyl chloride followed by Michael＇s addition. Twelve esters, 1a-1d, 4a-4d and 5a-5d, were synthesized and evaluated by using MTT assay method. The results demonstrate that all these compounds show a potential eytotoxicity on KB, HT-29, HCT-8, and Bel7402 tumor cell lines. Some compounds, 1d, 4c, 5b, 5c and 5d, show a higher cytoto-xicity on KB and HCT-8 compared with eamptotheein.

关键词： Camptothecin β-Aminopropionate Anticancer Synthesis

Physiological and Molecular Response of Wheat Roots to Nitrate Supply in Seedling Stage

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Agricultural Sciences in China 2011年第5期10卷 695-704页

作者： WANG Ping WANG Zhen-lin CAI Rui-guo LI Yong chen xiao-guang YIN Yan-ping State Key Laboratory of Crop Biology/Shandong Key Laboratory of Crop Biology/Agronomy College Shandong Agricultural University Tai＇an 271018 P.R.China Agronomy Department Hebei Normal University of Science and Technology Changli 066600 P.R. China

The objective of this study was to understand the morphological,physiological,and molecular responses of wheat roots to nitrate supply at seedling *** wheat genotypes,Jimai 22 and Shannong 15,were grown in Hoagland＇s nutrient solution with different nitrate levels at seedling *** indicated that the plant dry weight and N accumulation increased with the increase of nitrate *** number of axial root,total uptake area （TUA）,and active uptake area （AUA） increased with more nitrate *** analysis indicated that significant positive correlations existed between N accumulation and dry weight,N accumulation and AUA,and N accumulation and AUA/***,the expressions of NRT2.1,NRT2.2,and NRT2.3 decreased with nitrate supply increased,the expressions of NRT1,NRT2.1,and NRT2.3 could maintain high level at N3 *** free amino acid and NO3- content in shoot also increased with the increased nitrate application,but no significant difference was found in root among the *** results implied that the increase of N uptake by nitrate supply was due to the morphological and physiological responses of wheat roots and the high expression level of TaNRT ***,the contribution of morphological,physiological,and molecular parameters was different between two genotypes of wheat.

关键词： wheat root parameters nitrate uptake N metabolites TaNRT expression

ATF3 promotes ferroptosis by suppressing system Xc-

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中国药理学与毒理学杂志 2019年第10期 776-777页

作者： WANG Li-yuan LIU Yi-chen DU Ting-ting chen xiao-guang YAN Chun-hong Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Georgia Cancer Center Harbin Commercial University Department of Biochemistry and Molecular Biology Medical College of Georgia Augusta University

OBJECTIVE The amino acid antiporter system Xc;is important for the synthesis of glutathione（GSH） that functions to prevent lipid peroxidation and protect cells from nonapoptotic, iron-dependent death（ie, ferroptosis）. Inhibition of system Xc;activity by small molecules（eg, erastin） can cause a decrease in the intracellular GSH level, leading to ferroptotic cell death. While the activity of system Xc;is mainly determined by the expression level of its subunit encoded by the gene SLC7A11, the mechanism by which system Xc;is regulated during ferroptosis remains largely unknown. The goal of this study is to determine whether ATF3, a common stress sensor, can regulate system Xc;activity and promote ferroptosis. METHODS Ferroptosis was evaluated by cell viability assays and confirmed by treating cells with ferrostatin-1. Lipid peroxidation was measured by flow cytometry after cell staining with BODIPY 581/591C11. The activity of system Xc;was measured by glutamate release and GSH assay. The binding of ATF3 to the SLC7A11 promoter was determined by chromatin immunoprecipitation and DNA affinity precipitation assays. The activity of SLC7A11 promoter or mutated promoters was measured by dual luciferase reporter assays. RESULTS Overexpression of ATF3 in various cancer cells（eg, HT1080） promoted lipid peroxidation and ferroptosis induced by erastin and other ferroptosis inducers（eg, RSL3）. Conversely, knockout of ATF3 expression blocked the accumulation of lipid peroxides and prevented cells from undergoing ferroptosis. ATF3 appeared to promote ferroptosis by inhibiting system Xc;,as ATF3 expression decreased, while ATF3 knockout increased, the amount of released glutamate and the intracellular GSH level. Moreover, bypassing system Xc;by treating cells with 2-mercaptoethanol（2-ME） or N-acetylcysteine（NAC） could alleviate the effects of ATF3 on ferroptosis. Mechanistically, ATF3 strongly bound to the SLC7 A11 promoter and repressedits activity. Mutating the putative ATF3-bindin

关键词： ATF3 ferroptosis SLC7A11 system Xc~- metabolic stress erastin p53

基于直接判决和导频跟踪的OFDM系统快时变信道估计

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通信学报 2006年第9期27卷 1-5,13页

作者：陈晖陈晓光复旦大学通信科学与工程系上海200433

提出了一种基于直接判决的OFDM系统的快时变信道估计方法。采用了直接判决算法进行信道估计,并从中选择有效的估计结果,联合导频信号进行信道跟踪。将基于训练序列的信道估计结果作为直接判决算法的初始值,利用传输信号直接判决的统计... 详细信息

提出了一种基于直接判决的OFDM系统的快时变信道估计方法。采用了直接判决算法进行信道估计,并从中选择有效的估计结果,联合导频信号进行信道跟踪。将基于训练序列的信道估计结果作为直接判决算法的初始值,利用传输信号直接判决的统计特性进行了信道估计,并利用改进的导频算法进一步地跟踪信道在时间上的变化。Simulink仿真结果表明,该估计算法适用于时变信道,比基于导频的信道估计方法和基于训练序列的信道估计方法效果都要好。

关键词：正交频分复用时变信道多普勒频移直接判决导频训练序列信道估计

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超高效厌氧生物反应器床层膨胀行为的研究

高校化学工程学报 2009年第6期23卷 1001-1006页

作者：陈小光郑平浙江大学环境与资源学院浙江杭州310029

采用厌氧颗粒污泥和实验室模拟产气,系统研究了超高效厌氧生物反应器的床层膨胀行为。以床层膨胀率、最大污泥量和最大泥水接触时间作为膨胀行为表征参数,分别建立了固定态、流化态和输送态行为模型,模型计算值与试验值吻合较好。固定态... 详细信息

采用厌氧颗粒污泥和实验室模拟产气,系统研究了超高效厌氧生物反应器的床层膨胀行为。以床层膨胀率、最大污泥量和最大泥水接触时间作为膨胀行为表征参数,分别建立了固定态、流化态和输送态行为模型,模型计算值与试验值吻合较好。固定态时,ul≤0.45mm·s-1,床层膨胀率为0,最大污泥量为4867mL(床层有效体积为7850mL),最大泥水接触时间逐渐逼近860s(HRT最大值为2222s);流化态时,0.45mm·s-16.88mm·s-1,颗粒污泥洗出床层。反应器高效稳定运行时,床层处于流化态,其床层膨胀率、最大污泥量和最大泥水接触时间分别逼近160%、1860mL和104s。

关键词：厌氧反应器膨胀行为流化态固定态输送态

Mechanism of the protective effects of noninvasive limbs preconditioning on myocardial ischemia-reperfusion injury

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Chinese Medical Journal 2005年第20期118卷 1723-1727页

作者： chen xiao-guang WU Bin-yang WANG Jun-ke BAI Tao Department of Anesthesiology First Affiliated Hospital ChinaMedical University Shenyang 110001 China

Background This study aimed at assessing the effect of noninvasive limb preconditioning on myocardial infarct size, and determining whether nitric oxide and neurogenic pathway play an important role in the mechanism of acute remote ischemic preconditioning （IPC）.Methods Forty Wistar rats were randomly divided into four experimental groups. In Group I , the rats underwent 30-minute occlusion of the left anterior descending coronary artery, and 120-minute reperfusion. In Group PL, the rats underwent four cycles of 5-minute occlusion and reperfusion of both hind limbs using a tourniquet before the experiment was continued as in Group I. In Group PL-N and Group PL-,, we administered L-nitro-arginine methyl ester （L-NAME） 10 mg/kg or hexamethonium chloride 20 mg,/kg intravenously, 10 minutes before IPC. Infarct size as a percentage of the area at risk was determined by triphenyhetrazolium chloride staining.Results There were no statistically significant differences in mean arterial pressure and heart rate among these groups at any time point during the experiment （ P〉0. 05 ）. The myocardial infarct size （IS） was decreased significantly in Group PL and Group PL-U compared with Group I , and the IS/AAR was 34. 5%± 7.6%, 35.9%±8.6% and58.5%±8.5%, respectively （P〈0.05）. The IS/AAR was 49.1%±6.5% in Group PEN, and there was no significant difference compared with Group I （P〉0. 05 ）.Conclusions Noninvasive limb IPC is effective in protecting the myocardium from ischemia reperfusion injury. Nitric oxide plays an important role in the mechanism of acute remote IPC, in which the neurogenic pathway is not involved.

关键词： limb preconditioning ·ischemia-reperfusion injury myocardial protection· nitric oxide·neurogenic pathway

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Gabor滤波器的快速实现

自动化学报 2007年第5期33卷 456-461页

作者：陈小光封举富北京大学信息科学技术学院智能科学系视觉与听觉信息处理国家重点实验室北京100871

本文提出了Gabor滤波器的两种快速实现方法．这两种方法首先把Gabor滤波器分解为多个不同方向上有着不同参数的一维高斯滤波器的组合,然后通过递归的方法分别实现这些高斯滤波器,从而实现Gabor滤波器．实验和分析结果表明,本文提出的Ga... 详细信息

本文提出了Gabor滤波器的两种快速实现方法．这两种方法首先把Gabor滤波器分解为多个不同方向上有着不同参数的一维高斯滤波器的组合,然后通过递归的方法分别实现这些高斯滤波器,从而实现Gabor滤波器．实验和分析结果表明,本文提出的Gabor滤波器的快速实现方法,不论是计算复杂度还是计算精度,都比基于卷积的标准实现方法有着更好的性能和效果．

关键词： Gabor滤波高斯滤波器非正交分解递归滤波快速算法

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一种基于奇异点的指纹校准方法

模式识别与人工智能 2006年第2期19卷 203-207页

作者：陈沛华陈晓光复旦大学通信科学与工程系上海200433

提出一种新的指纹图像校准算法.通过多分辨率的方法对指纹奇异点进行定位,既保证奇异点位置的精确性,也减少运算时间.通过分析指纹图像的方向场,核心方向被精确而快速地计算出来.在这两者的基础上基准点得到有效确定,然后根据基准点的... 详细信息

提出一种新的指纹图像校准算法.通过多分辨率的方法对指纹奇异点进行定位,既保证奇异点位置的精确性,也减少运算时间.通过分析指纹图像的方向场,核心方向被精确而快速地计算出来.在这两者的基础上基准点得到有效确定,然后根据基准点的位置和方向对现场指纹和数据库中指纹进行校准.与通常所用的点模式校准算法相比,本文提出的算法在复杂度上有所降低.而且受图像质量的影响较小.初步实验结果表明本文方法的有效性.在指纹图像质量较好时,本文方法在实现效率上有一定优势.

关键词：指纹识别指纹校准算法奇异点指纹匹配