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Coactivation Does Not Contribute to Fatigue-Induced Decreases in Isokinetic Forearm Flexion and Extension Torque
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作者 Tyler J.Neltner John Paul V.Anders +5 位作者 Robert W.Smith Jocelyn E.Arnett Joshua L.Keller Terry J.Housh Richard J.Schmidt Glen O.Johnson 《Journal of Science in Sport and Exercise》 CSCD 2023年第4期314-321,共8页
Purpose The present study examined the effects of a reciprocal,slow velocity forearm flexion and extension task on fatigue-induced changes in isokinetic torque,agonist and antagonist muscle activation,and coactivation... Purpose The present study examined the effects of a reciprocal,slow velocity forearm flexion and extension task on fatigue-induced changes in isokinetic torque,agonist and antagonist muscle activation,and coactivation ratios at slow and moderate velocities.Methods Nine women(mean±SD:age=21.0±1.7 years;body mass=68.1±8.2 kg;height=167.4±7.2 cm)completed pre-testing for forearm flexion and extension isokinetic peak torque at 60 and 180°/s,a fatiguing task of 50 maximal,recip-rocal,isokinetic muscle actions at 60°/s,and post-testing.The amplitude(AMP)of the electromyographic(EMG)signals from the biceps and triceps were simultaneously recorded.Torque and EMG AMP were normalized to the corresponding values from the pre-testing peak torque movements.Repeated measures ANOVAs and pairwise comparisons were used to identify mean changes in torque,EMG AMP,and coactivation ratios.Results The torque analyses indicated significant decreases from pre-to post-testing for forearm flexion(14.1%±5.0%;P<0.001)and extension(25.4%±12.2%;P<0.001)at 60°.At 180°/s there was a significant decrease,collapsed across the forearm movements(24.7%±11.7%;P<0.001).For EMG AMP and coactivation ratios,there were no changes(P>0.05)from pre-to post-testing for either velocity or movement.Conclusions The torque responses were velocity-specific,with greater fatigability exhibited for forearm extension versus flexion at 60°/s,but no differences at 180°/s.The parallel EMG AMP responses between the agonist and antagonist muscles for both velocities supported the lack of fatigue-induced changes in coactivation ratios.Thus,our results demonstrated that fatigue-induced decreases in torque were not attributable to increases in antagonist activation or coactivation. 展开更多
关键词 coactivation ISOKINETIC FATIGUE Forearm flexion Extension
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Computational design of BC_(3)N_(2) based single atom catalyst for dramatic activation of inert CO_(2) and CH4 gasses into CH_(3)COOH with ultralow CH_(4) dissociation barrier
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作者 Chenxu Zhao Menghui Xi +2 位作者 Jinrong Huo Chaozheng He Ling Fu 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第1期493-498,共6页
The production of CH_(3)COOH from CO_(2)and CH_(4) has stimulated much interest due to the high energy density of C2 species.Various kinds of catalysts have been developed while the high dissociation barrier of CH_(4)... The production of CH_(3)COOH from CO_(2)and CH_(4) has stimulated much interest due to the high energy density of C2 species.Various kinds of catalysts have been developed while the high dissociation barrier of CH_(4) and low selectivity still hinders the efficiency of the reaction.We have herein proposed a novel catalyst with single metals loaded on 2D BC_(3)N_(2) substrate(M@2D-BC_(3)N_(2))based on density functional theory.Among numerous candidates,Pt@2D-BC_(3)N_(2) possesses the most favorable reactivity with an ultralow barrier of CH_(4) splitting(0.26 e V),which is due to the efficient capture ability of CH_(4) on Pt site.Besides,the selectivity for CH_(3)COOH is also very high,which mainly stems from the unique electronic properties of molecules and substrate:The degenerated states,including s,px,pyand pz,in CO_(2)reflects the existence of delocalizedπbonds between C and O.This can interact with states of Pt(s),Pt(pz),Pt(dxz),Pt(dyz),and Pt(z2)in Pt@2D-BC_(3)N_(2).The kinetics model also proves that our system can promote CH_(3)COOH production via simply increasing the temperature or the coverage of CH_(4) and CO_(2).Our results provide a reasonable illustration in clarifying mechanism and propose promising candidates with high reactivity for further study. 展开更多
关键词 Density functional theory CO_(2)/CH4 coactivation 2D BC_(3)N_(2)substrate CH_(3)COOH production
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Multiplex and optimization of dCas9-TV-mediated gene activation in plants 被引量:3
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作者 Xiangyu Xiong Jieping Liang +2 位作者 Zhenxiang Li Ben-Qiang Gong Jian-Feng Li 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2021年第4期634-645,共12页
Synthetic gene activators consisting of nucleasedead Cas9(dCas9)for single-guide RNA(sgRNA)-directed promoter binding and a transcriptional activation domain(TAD)represent new tools for gene activation from endogenous... Synthetic gene activators consisting of nucleasedead Cas9(dCas9)for single-guide RNA(sgRNA)-directed promoter binding and a transcriptional activation domain(TAD)represent new tools for gene activation from endogenous genomic locus in basic and applied plant research.However,multiplex gene coactivation by d Cas9-TADs has not been demonstrated in whole plants.There is also room to optimize the performance of these tools.Here,we report that our previously developed gene activator,dCas9-TV,could simultaneously upregulate OsGW7 and OsER1 in rice by up to 3,738 fold,with one sg RNA targeting to each promoter.The gene coactivation could persist to at least the fourth generation.Astonishingly,thepolycistronictRNA-sgRNAexpression under the maize ubiquitin promoter,a Pol II promoter,could cause enormous activation of these genes by up to>40,000-fold in rice.Moreover,the yeast GCN4 coiled coil-mediated dCas9-TV dimerization appeared to be promising for enhancing gene activation.Finally,we successfully introduced a self-amplification loop for dCas9-TV expression in Arabidopsis to promote the transcriptional upregulation of AtFLS2,a previously characterized dCas9-TV-refractory gene with considerable basal expression.Collectively,this work illustrates the robustness of dCas9-TV in multigene coactivation and provides broadly useful strategies for boosting transcriptional activation efficacy of dCas9-TADs in plants. 展开更多
关键词 dCas9-TV HERITABILITY self-amplification loop multiplex gene coactivation synthetic transcription activator
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鞍座高度对女性休闲骑行中下肢肌肉协调及踏板力的影响 被引量:1
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作者 王勇 梁雷超 +3 位作者 汤运启 黄灵燕 伍勰 刘宇 《中国体育科技》 CSSCI 北大核心 2022年第2期55-61,共7页
目的:通过设置骑行时不同鞍座高度,以了解鞍座高度变化对骑行时下肢肌肉活动、肌群间协调关系以及踏板输出力的影响。方法:10名受试者以随机顺序完成3种(自选高度座高,P;较低高度座高,L;较高高度座高,H)鞍座高度下的骑行,采用Delsys无... 目的:通过设置骑行时不同鞍座高度,以了解鞍座高度变化对骑行时下肢肌肉活动、肌群间协调关系以及踏板输出力的影响。方法:10名受试者以随机顺序完成3种(自选高度座高,P;较低高度座高,L;较高高度座高,H)鞍座高度下的骑行,采用Delsys无线表面肌电测试系统、三维脚蹬测力台和三维红外动作捕捉系统,同步采集下肢肌肉肌电数据、踏板反作用力和下肢运动学;使用三维分析软件、Matlab软件计算分析连续10个踩踏周期的运动学、动力学和肌电指标。结果:鞍座高度对臀大肌、股内侧肌和股二头肌等肌肉活动强度产生了影响(P<0.05);采用最高鞍座骑行时臀大肌、半腱肌和股二头肌活动持续时间增加(P<0.05),股直肌/臀大肌具有最小的共激活(P<0.05);股二头肌/股内侧肌、腓肠肌内侧/股内侧肌共激活随座高的增加而增加(P<0.05),腓肠肌内侧/胫骨前肌共激活没有受到座高影响(P>0.05);踏板力随座高的增加而减小(P<0.05),有效力没有受到座高影响(P>0.05)。结论:恒定功率骑行时,较高的鞍座高度引起下肢部分肌肉活动强度增加,活动持续时间增加,但导致股内侧肌活动强度和跨过髋关节的拮抗肌共激活降低,同时踏板力降低。因此,不建议采用过高的鞍座高度骑行。 展开更多
关键词 骑行 鞍座高度 协调 共激活
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脑卒中后偏瘫上肢屈肌异常共激活的表面肌电研究 被引量:11
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作者 程迎 高晓平 +3 位作者 李嫣然 陈和木 王冬 张旭 《安徽医科大学学报》 CAS 北大核心 2016年第6期888-893,共6页
目的通过采集偏瘫上肢屈肌在执行屈肘、屈腕最大等长随意收缩时的表面肌电信号,分析上肢屈肌共激活模式,并探索其与偏瘫上肢运动功能障碍的相关性。方法选取18例仅发生1次单一的脑梗死或脑出血的偏瘫患者纳入卒中组;同时募集18例年龄、... 目的通过采集偏瘫上肢屈肌在执行屈肘、屈腕最大等长随意收缩时的表面肌电信号,分析上肢屈肌共激活模式,并探索其与偏瘫上肢运动功能障碍的相关性。方法选取18例仅发生1次单一的脑梗死或脑出血的偏瘫患者纳入卒中组;同时募集18例年龄、性别与卒中组相匹配的健康志愿者纳入对照组。分别完成等长屈肘、屈腕运动,期间同时记录肱二头肌、桡侧腕屈肌的表面肌电信号。通过提取相关肌电参数,比较卒中组健侧、卒中组偏瘫侧、对照组在屈肘、屈腕最大等长收缩过程中,肱二头肌与桡侧腕屈肌的共激活程度,并分析其与运动功能障碍的相关性。结果卒中组偏瘫侧上肢屈肌的共激活程度大于健侧(P<0.05)。比较卒中组健侧与对照组,屈腕共激活程度健侧大于对照组(P<0.05),屈肘共激活程度两者差异无统计学意义。偏瘫上肢屈肌的共激活程度与上肢Fugl-Meyer评分、协调性评分呈负相关性,与上肢痉挛程度呈正相关性。结论脑卒中后偏瘫侧及健侧上肢屈肌均存在异常的共激活现象,且共激活程度与运动功能障碍密切相关。脊髓调节通路异常可能为共激活的原因。 展开更多
关键词 脑卒中 偏瘫 异常共激活 表面肌电
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多感觉整合测量范式中存在的影响因素探讨 被引量:6
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作者 孙远路 胡中华 +3 位作者 张瑞玲 寻茫茫 刘强 张庆林 《心理学报》 CSSCI CSCD 北大核心 2011年第11期1239-1246,共8页
已有的多感觉整合研究范式多采用不同单通道刺激和双通道刺激随机呈现的方式进行测量。在这种范式中混有通道转换效应,该效应可能导致多感觉整合的测量结果不准确。因此,分析清楚实验范式中通道转换效应的影响因素,并以此为依据设计合... 已有的多感觉整合研究范式多采用不同单通道刺激和双通道刺激随机呈现的方式进行测量。在这种范式中混有通道转换效应,该效应可能导致多感觉整合的测量结果不准确。因此,分析清楚实验范式中通道转换效应的影响因素,并以此为依据设计合理的整合测量范式,是进行多感觉整合研究的一个必要前提。本文首先通过实验一验证了在经典的整合测量范式中通道转换效应的影响方式;进而,在实验二中通过控制前后刺激的信号强度的一致性,分析了通道转换效应的特点。综合分析显示,通道转换效应是由前一刺激差异所造成的对当前刺激通道加工的注意资源分配和警觉水平的变化所导致。该结果表明,在多感觉行为测量中,需先根据前一刺激通道分类后再进行分析。 展开更多
关键词 多感觉整合 通道转换 竞争模型 同激活模型
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孤独症谱系障碍默认网络与任务正激活网络交互的共激活模式研究
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作者 郑清予 李镭 +2 位作者 肖金明 陈华富 段旭君 《中华精神科杂志》 CAS CSCD 北大核心 2023年第4期284-291,共8页
目的探究孤独症谱系障碍(autism spectrum disorder,ASD)默认网络关键节点共激活模式异常及其与临床症状严重程度的关系。方法本研究在多中心、大样本的静息态功能磁共振成像数据集ASD脑影像公开交换数据库(Autism Brain Imaging Data E... 目的探究孤独症谱系障碍(autism spectrum disorder,ASD)默认网络关键节点共激活模式异常及其与临床症状严重程度的关系。方法本研究在多中心、大样本的静息态功能磁共振成像数据集ASD脑影像公开交换数据库(Autism Brain Imaging Data Exchange,ABIDE)中筛选被试者,包括ASD患者354例(ASD组)、健康对照者446名(对照组),采用共激活模式分析方法分析ASD默认网络关键节点(内侧前额叶)的共激活模式特征及其与默认网络内部其他节点、任务正激活网络之间的交互异常。采用网络分离指数(network dissociation index,NDI)评估网络内与网络间功能分离的程度,并以NDI为特征采用多变量支持向量回归方法对ASD临床症状进行预测,组间比较采用双样本t检验。结果内侧前额叶处于激活状态时,ASD组默认网络楔前叶的激活较对照组显著降低(t=-4.21,P<0.01),而突显网络的背侧前扣带回和眶额-脑岛联合区的激活较对照组显著升高(t=2.93、2.61,均P<0.05)。且相较于对照组,ASD组默认网络内的NDI显著升高(t=3.63,P<0.01),默认网络(内侧前额叶)与突显网络(背侧前扣带回与眶额-脑岛联合区)间的NDI则显著降低(t=-2.97、-3.31,均P<0.01)。将NDI作为特征放入支持向量回归模型中,可预测ASD的社交、言语缺陷及疾病严重程度(r=0.191、0.216、0.186,均P<0.01)。结论静息态下ASD患者内侧前额叶的共激活模式存在异常,默认网络内部的功能整合协同能力下降,并且与任务正激活网络的功能分离程度也降低,这种异常的网络功能模式与临床症状密切相关。 展开更多
关键词 孤独性障碍 共激活模式 功能整合与分离 默认网络 任务正激活网络
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行为性LTP产生机制的初探
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作者 易立 《云南师范大学学报(自然科学版)》 1990年第Z2期88-90,共3页
本文对于行为性LTP产生机制进行了初步研究。结果表明行为性LTP的产生机制可能不同于高频刺激所产生的LTP那样是依赖于一束纤维的同步活化,可能与海马内神经元活动和各个环路之间的相互作用有关,也就是说是一种共同激活的结果。
关键词 行为性LTP 产生机制 共同激活
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膝关节骨关节炎患者膝屈伸肌的表面肌电信号研究 被引量:45
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作者 俞晓杰 吴毅 +3 位作者 胡永善 白玉龙 李美萍 沈健 《中华物理医学与康复杂志》 CAS CSCD 北大核心 2006年第6期402-405,共4页
目的评价单侧膝关节骨关节炎(OA)患者在不同运动状态下的健、患侧膝屈伸肌的肌肉功能和协调活动差异,为临床制定康复方案提供依据。方法用Noraxon Myosystem1200型表面肌电图仪对26例单侧膝关节骨关节炎患者的等长肌肉收缩功能和下蹲运... 目的评价单侧膝关节骨关节炎(OA)患者在不同运动状态下的健、患侧膝屈伸肌的肌肉功能和协调活动差异,为临床制定康复方案提供依据。方法用Noraxon Myosystem1200型表面肌电图仪对26例单侧膝关节骨关节炎患者的等长肌肉收缩功能和下蹲运动进行表面肌电信号的测试。结果患侧股外侧肌和股二头肌在最大等长收缩和下蹲运动时的肌电振幅均值小于健侧(P<0.05)。在最大等长收缩过程中,患侧的拮抗肌协同收缩率较健侧增高(P<0.05);在下蹲运动过程中,患侧的腘绳肌共同活动比率高于检测(P<0.05)。结论表面肌电图测试可用于量化评价膝OA患者在不同运动过程中肌肉功能。膝OA患肢在不同运动状态下均可能存在肌肉功能降低和肌力平衡异常。康复治疗不仅应重视股四头肌肌力增强而且应重视改善膝关节的肌力平衡。 展开更多
关键词 骨关节炎 表面肌电图 膝关节 协同活动
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Coactive design of explainable agent-based task planning and deep reinforcement learning for human-UAVs teamwork 被引量:15
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作者 Chang WANG Lizhen WU +3 位作者 Chao YAN Zhichao WANG Han LONG Chao YU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第11期2930-2945,共16页
Unmanned Aerial Vehicles(UAVs)are useful in dangerous and dynamic tasks such as search-and-rescue,forest surveillance,and anti-terrorist operations.These tasks can be solved better through the collaboration of multipl... Unmanned Aerial Vehicles(UAVs)are useful in dangerous and dynamic tasks such as search-and-rescue,forest surveillance,and anti-terrorist operations.These tasks can be solved better through the collaboration of multiple UAVs under human supervision.However,it is still difficult for human to monitor,understand,predict and control the behaviors of the UAVs due to the task complexity as well as the black-box machine learning and planning algorithms being used.In this paper,the coactive design method is adopted to analyze the cognitive capabilities required for the tasks and design the interdependencies among the heterogeneous teammates of UAVs or human for coherent collaboration.Then,an agent-based task planner is proposed to automatically decompose a complex task into a sequence of explainable subtasks under constrains of resources,execution time,social rules and costs.Besides,a deep reinforcement learning approach is designed for the UAVs to learn optimal policies of a flocking behavior and a path planner that are easy for the human operator to understand and control.Finally,a mixed-initiative action selection mechanism is used to evaluate the learned policies as well as the human’s decisions.Experimental results demonstrate the effectiveness of the proposed methods. 展开更多
关键词 coactive design Deep reinforcement learning Human-robot teamwork Mixed-initiative Multi-agent system Task planning UAV
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激素相关核受体及其辅助激活因子与骨质疏松症 被引量:5
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作者 魏秋实 黄莉 邓伟民 《生命科学》 CSCD 2013年第7期694-699,共6页
核受体是一类在生物体内分布广泛、成员众多的转录因子,参与体内亲脂激素、维生素、脂质和其他细胞内信号的转录过程。核受体与相应的配体及其辅助因子相互作用,调控众多靶基因的表达,在机体的生长发育、新陈代谢、细胞分化及体内许多... 核受体是一类在生物体内分布广泛、成员众多的转录因子,参与体内亲脂激素、维生素、脂质和其他细胞内信号的转录过程。核受体与相应的配体及其辅助因子相互作用,调控众多靶基因的表达,在机体的生长发育、新陈代谢、细胞分化及体内许多生理过程中发挥重要作用。为了探讨激素相关核受体及其辅助激活因子与骨质疏松之间的关系,通过检索有关激素核受体、核受体辅助因子的功能与骨质疏松的相关文献并进行综述,阐明了激素相关核受体(ER、AR、ERRα、PPARγ)及其辅助激活因子(SRC-1、SRC-2)在骨骼发育中的重要作用,而核受体辅助激活因子SRC-3、PGC-1α可能参与成骨细胞的增殖和分化过程,但作用机制尚不清楚。因此,深入研究SRC-3、PGC-1α在骨代谢中的作用,将为我们深入了解骨质疏松的发病机制具有重要意义。 展开更多
关键词 核受体 核受体辅助共激活因子 骨质疏松
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CANFIS—a computer aided diagnostic tool for cancer detection
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作者 Latha Parthiban R. Subramanian 《Journal of Biomedical Science and Engineering》 2009年第5期323-335,共13页
In this investigation, an approach using Coac-tive Neuro-Fuzzy Inference System (CANFIS) as diagnosis system for breast cancer has been proposed on Wisconsin Breast Cancer Data (WBCD). It is occasionally difficult to ... In this investigation, an approach using Coac-tive Neuro-Fuzzy Inference System (CANFIS) as diagnosis system for breast cancer has been proposed on Wisconsin Breast Cancer Data (WBCD). It is occasionally difficult to attain the ultimate diagnosis even for medical experts due to the complexity and non-linearity of the rela-tionships between the large measured factors, which can be possibly resolved with a human like decision-making process using Artificial Intelligence (AI) algorithms. CANFIS is an AI algorithm which has the advantages of both fuzzy inference system and neural networks and can deal with ambiguous data and learn from the past data by itself. The Multi Layer Percep-tron Neural Network (MLPNN), Probabilistic Neural Network (PNN) Principal Component Analysis (PCA), Support Vector Machine (SVM) and Self Organizing Map (SOM) were also tested and benchmarked for their 展开更多
关键词 NEURAL NETWORK coactive NEURO-FUZZY INFERENCE Systems Probabilistic NEURAL NETWORK Principal Component Analysis STERN Series WISCONSIN Breast Cancer Data
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Sleep deprivation reorganizes the dynamic configurations of default mode network activity during recovery sleep
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作者 CUI Yan WU ShengDun +8 位作者 ZHAO Shi LONG TianYao JIAN ZhaoXin YU Shuang ZHANG Ge BISWAL Bharat GUO DaQing XIA Yang YAO DeZhong 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2022年第7期1456-1469,共14页
Sleep deprivation causes disturbances of the neural activity, leading to the impairment of brain functions. However, the exact mechanism of sleep deprivation and how it affects the dynamics of brain activity during th... Sleep deprivation causes disturbances of the neural activity, leading to the impairment of brain functions. However, the exact mechanism of sleep deprivation and how it affects the dynamics of brain activity during the recovery sleep remains unclear. In the current study, we performed sleep deprivation experiments on ten adult rats, and recorded the local field potentials from default mode network(DMN) regions during sleep before and after sleep deprivation. The DMN dynamics was assessed with the configurations of coactive micropatterns(CAMPs) using our previously proposed CAMP method. Our analysis revealed that the effects of sleep deprivation on DMN dynamics in the slow-wave sleep(SWS) state and the rapid eye-movement sleep(REM)state were disparate. Dynamic configurations of DMN activity in the SWS state were significantly impaired after sleep deprivation, with increased occurrence of low-activity CAMP and reorganized transition structure across three CAMPs. Moreover,enhanced functional connectivity and improved efficiencies in all CAMP networks were observed during the SWS state in the recovery sleep. However, there were no significant alterations in either DMN dynamics or CAMP network structures in the REM sleep state after sleep deprivation. Our results described the alterations of DMN dynamics in different sleep states after sleep deprivation, and illustrated the differential effects of sleep deprivation on two sleep states. These findings demonstrated the underlying neural mechanisms of the effects of sleep deprivation on DMN activity during sleep and increased our understanding of the physiological roles of the DMN in maintain sleep homeostasis after sleep deprivation. 展开更多
关键词 sleep deprivation sleep state default mode network coactive micropattern dynamic configuration EFFICIENCY
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Gene Expression Pattern of Histone Acetylation Enzymes Changed in the Hypothalamus of Middle-Aged Female Rats:A Putative Mechanism for Female Reproductive Aging 被引量:1
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作者 Wen Xu Na Zhang +5 位作者 Li-Sha Li Yan Wang Lin Wang Mei-Rong Du Da-Jin Li Yan Sun 《Reproductive and Developmental Medicine》 CSCD 2018年第2期65-73,共9页
Objective:Female reproductive aging is characterized by reduced responsiveness of the hypothalamus to E2-positive feedback,which can result in alterations of gene expression and luteinizing hormone(LH)surge dysfunctio... Objective:Female reproductive aging is characterized by reduced responsiveness of the hypothalamus to E2-positive feedback,which can result in alterations of gene expression and luteinizing hormone(LH)surge dysfunction.We hypothesize that age-related changes in E2-responsive gene expression are due to altered histone acetylation by histone deacetylases(HDACs)or estrogen receptor-alpha(ERα)coactivators with histone acetyltransferase(HAT)activity.Methods:In the present study,young and middle-aged female rats were ovariectomized(OVX)and treated with E2 or oil once per day for 2 days.At the time of the expected LH surge,the anterior and posterior hypothalami were dissected,and gene expression of 11 HDACs and 4 ERαcoactivators with HAT activity was measured using real-time polymerase chain reaction.Results:In the anterior hypothalamus,age affected the gene expression of 3 HDACs(Hdac3,Hdac5,and Hdac11)and 2 ERαcoactivators(Src2 and Crebbp).E2 treatment significantly decreased mRNA levels of 4 HDACs(Hdac4,Hdac5,Hdac10,and Hdac11)and 2 ERαcoactivators(Src2 and Crebbp)in young females(3-4 months).However,none of the genes responded to E2 in the middle-aged females(9-11 months),except Hdac10.In the posterior hypothalamus,age influenced Hdac5 and Src1 mRNA expression.E2 treatment increased Hdac4 and Crebbp mRNA levels in the young but not middle-aged females.Conclusions:These data suggest that E2 regulates HDACs and ERαcoactivators with HAT activity in an age-and E2-dependent manner,which may contribute to the age-related gene expression changes on the day of LH surge in female reproductive aging. 展开更多
关键词 Aging Estradiol‑Positive Feedback Estrogen Receptor‑Alpha coactivators Histone Deacetylases HYPOTHALAMUS
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核受体及核受体辅活化子对芳香族化酶基因转录调控的研究 被引量:1
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作者 周度金 杨春 +6 位作者 周长保 陈彬 陈敏 陈健 李渝萍 张放鸣 陈煊 《第三军医大学学报》 CAS CSCD 北大核心 2001年第12期1421-1424,共4页
目的 研究核受体及核受体辅活化子对芳香族化酶基因转录的调控。方法 酵母单、双杂合筛选、蛋白质 蛋白质相互作用分析、DNA突变、报告基因转染功能分析、迁移率改变及足迹分析等技术。结果 ①鉴定了主导芳香族化酶基因在乳腺癌细胞... 目的 研究核受体及核受体辅活化子对芳香族化酶基因转录的调控。方法 酵母单、双杂合筛选、蛋白质 蛋白质相互作用分析、DNA突变、报告基因转染功能分析、迁移率改变及足迹分析等技术。结果 ①鉴定了主导芳香族化酶基因在乳腺癌细胞中表达的启动子I.3和启动子Ⅱ的确切位置以及对这两个启动子起调节作用的沉默子 (Silencer)S1和cAMP效应要素 (CREaro)等顺式作用元件。②分离鉴定了能与类固醇衍生因子 1 (SterodogenicFactor1 ,SF1 )相互作用并参与芳香族化酶基因转录调控的转录因子 ,其中近 5 0 %的克隆编码两种新的富含脯氨酸的核受体辅调节蛋白质 ,命名为PNRC(Proline richNuclearReceptorCoactivators)。功能分析显示PNRC通过与SF1或ERR1相互作用 ,进一步增强SF1或ERR1对芳香族化酶基因启动子 1 .3的转录激活作用。③缺失突变及定点突变分析证明含SH3结合模体的 2 3个氨基酸残基区域是PNRC分子与核受体的相互作用位点。结论 我们鉴定了主导芳香族化酶基因在乳腺癌细胞中表达的启动子及调控序列 ,克隆了与DNA调控序列结合的蛋白质和通过蛋白质相互作用参与芳香族化酶基因转录调控的转录因子———一种新型的核受体辅活化子PNRC。 展开更多
关键词 核受体 芳香族化酶 辅活化子 PNRC 基因表达调控 乳腺癌
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Distinct expression profiles of transcriptional coactivators for thyroid hormone receptors during Xenopus laevis metamorphosis
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作者 BINDU D PAUL YUN-Bo SHI 《Cell Research》 SCIE CAS CSCD 2003年第6期459-464,共6页
The biological effects of thyroid hormone (T3) are mediated by the thyroid hormone receptor (TR). Amphibian metamorphosis is one of the most dramatic processes that are dependent on T3. T3 regulates a series of orches... The biological effects of thyroid hormone (T3) are mediated by the thyroid hormone receptor (TR). Amphibian metamorphosis is one of the most dramatic processes that are dependent on T3. T3 regulates a series of orchestrated developmental changes, which ultimately result in the conversion of an aquatic herbivorous tadpole to a terrestrial carnivorous frog. T3 is presumed to bind to TRs, which in turn recruit coactivators, leading to gene activation. The best-studied coactivators belong to the p160 or SRC family. Members of this family include SRC1/NCoA-1, SRC2/TIF2/GRIP1, and SRC3/pCIP/ACTR/AIB-1/RAC-3/TRAM-1. These SRCs interact directly with liganded TR and function as adapter molecules to recruit other coactivators such as p300/CBP. Here, we studied the expression patterns of these coactivators during various stages of development. Amongst the coactivators cloned in Xenopus laevis, SRC3 was found to be dramatically upregulated during natural and T3-induced metamorphosis, and SRC2 and p300 are expressed throughout postembryonic development with little change in their expression levels. These results support the view that these coactivators participate in gene regulation by TR during metamorphosis. 展开更多
关键词 transcription coactivators thyroid hormone receptor Xenopus laevis METAMORPHOSIS histone acetylation.
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过氧化物酶体增殖物激活受体辅调节因子与肾脏损伤的关系
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作者 靳远萌 王伟铭 陈楠 《国际内科学杂志》 CAS 2007年第9期525-529,共5页
过氧化物酶体增殖物激活受体(PPARs)作为一类核转录因子,能与其特异性配体结合,进而在转录水平上调节多种基因的表达。近年来研究发现,PPARs的辅调节因子,包括辅激活因子和辅抑制因子,能够通过不同的机制促进或抑制PPARs的转录活性,调... 过氧化物酶体增殖物激活受体(PPARs)作为一类核转录因子,能与其特异性配体结合,进而在转录水平上调节多种基因的表达。近年来研究发现,PPARs的辅调节因子,包括辅激活因子和辅抑制因子,能够通过不同的机制促进或抑制PPARs的转录活性,调节其目的基因的表达。并且还是很多细胞内信号通路和翻译后修饰作用的对象,在肾脏疾病的进展中发挥重要重要。选择不同的辅调节因子的激活剂或抑制剂来调节相关基因的转录活性,将会成为治疗一些肾脏疾病如肾小球硬化、肾小球肾炎、糖尿病肾病及肾小管间质疾病的新的治疗手段和方法。 展开更多
关键词 过氧化物酶体增殖物激活受体 辅激活因子 辅抑制因子 肾脏损伤
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Targeting transcriptional regulators for treatment of anaplastic thyroid cancer
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作者 Woo Kyung Lee Sheue-Yann Cheng 《Journal of Cancer Metastasis and Treatment》 2021年第1期381-398,共18页
Dysregulation of genes perpetuates cancer progression.During carcinogenesis,cancer cells acquire dependency of aberrant transcriptional programs(known as“transcription addiction”)to meet the high demands for uncontr... Dysregulation of genes perpetuates cancer progression.During carcinogenesis,cancer cells acquire dependency of aberrant transcriptional programs(known as“transcription addiction”)to meet the high demands for uncontrolled proliferation.The needs for particular transcription programs for cancer growth could be cancer-type-selective.The dependencies of certain transcription regulators could be exploited for therapeutic benefits.Anaplastic thyroid cancer(ATC)is an extremely aggressive human cancer for which new treatment modalities are urgently needed.Its resistance to conventional treatments and the lack of therapeutic options for improving survival might have been attributed to extensive genetic heterogeneity due to subsequent evolving genetic alterations and clonal selections during carcinogenesis.Despite this genetic complexity,mounting evidence has revealed a characteristic transcriptional addiction of ATC cells resulting in evolving diverse oncogenic signaling for cancer cell survival.The transcriptional addiction has presented a huge challenge for effective targeting as shown by the failure of previous targeted therapies.However,an emerging notion is that many different oncogenic signaling pathways activated by multiple upstream driver mutations might ultimately converge on the transcriptional responses,which would provide an opportunity to target transcriptional regulators for treatment of ATC.Here,we review the current understanding of how genetic alterations in cancer distorted the transcription program,leading to acquisition of transcriptional addiction.We also highlight recent findings from studies aiming to exploit the opportunity for targeting transcription regulators as potential therapeutics for ATC. 展开更多
关键词 Transcriptional addiction TRANSCRIPTION oncogene addiction cancer stem cell thyroid hormone receptors steroid receptor coactivators BET inhibitor anaplastic thyroid cancer
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AUTONOMY AND CONTROL OF ADAPTIVE SYSTEMS OF SYSTEMS
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作者 MHAMED ITMI ALAIN CARDON 《International Journal of Modeling, Simulation, and Scientific Computing》 EI 2012年第1期116-136,共21页
We propose a unified approach for systems integration and behavior regulation expressing the autonomy of Systems of Systems. For this, we precise the notion of autonomyas a transposition of the living organisms case a... We propose a unified approach for systems integration and behavior regulation expressing the autonomy of Systems of Systems. For this, we precise the notion of autonomyas a transposition of the living organisms case and we develop the notion of artificial tendencies and behavioral intentions. We present a multi-agent model allowing theimplementation with a new multi-scale control. 展开更多
关键词 AUTONOMY coactivity multi-agent systems multi-scale control PROACTIVITY
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动物细胞的基因转录调控:来自生化研究的启示
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作者 Robert G.Roeder 周波 《生命科学》 CSCD 北大核心 2010年第3期232-236,共5页
在真核细胞中,转录调控可以发生在多个层面,包括结构和功能迥异的RNA聚合酶、对应的广谱起始因子、基因特异性调控因子(DNA结合蛋白)以及各种共调节因子(coregulatory factors)。这些共调节因子可以通过染色质修饰,如组蛋白乙酰化和甲基... 在真核细胞中,转录调控可以发生在多个层面,包括结构和功能迥异的RNA聚合酶、对应的广谱起始因子、基因特异性调控因子(DNA结合蛋白)以及各种共调节因子(coregulatory factors)。这些共调节因子可以通过染色质修饰,如组蛋白乙酰化和甲基化,或更直接地促进转录起始复合物的形成。通过一系列体外转录活性实验的研究,转录相关的酶、蛋白因子的性质和功能以及作用机制正逐步被揭示出来。该文将具体阐述近几十年科学家们在转录共调节因子方面取得的进展。 展开更多
关键词 转录调控 共调节因子 转录中介体 组蛋白修饰
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