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Antioxidant effects of green tea polyphenols

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chinese Science Bulletin 2003年第4期48卷 315-319页

作者： ZHAO Baolu laboratory of visual information processing, Research Centers of Brain and Cognitive Science, {4. of biophysics, chinese academy of sciences, beijing 100101, china laboratory of visual information processing Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

The unprecedented interest in the antioxidant activity of green tea polyphenols (GTP) is due to the appar-ent health benefits of tea drinking and the experimental re-sults with the polyphenols. The results suggest that the gal-loylated catechins show stronger antioxidant effect than that of nongalloylated catechins and the double bond in C ring also plays an important role in this effect. There are synergic effects between different catechins and the antioxidant effect of (+)-epimers is stronger than that of (-)-epimers. The active site to scavenge free radicals mainly locates in p-hydroxyl of phenol in gallic acid and hydroxyl of phenol in the pyrane also shows activity. The large p bond in chromane and benzene ring of catechin is the structure base for their anti-oxidant effects. The prevent effect of GTP against diseases and their redox regulation in cell signal pathway are very important to be studied in the future.

关键词：绿茶茶多酚天然抗氧化剂抗氧化作用生物类黄酮自由基抗衰老

Chronic morphine exposure induces degradation of receptive field properties of LGN cells in cats

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Acta Pharmacologica Sinica 2005年第9期26卷 1034-1038页

作者： Li-hua HE~2 Guang-xing LI~2 Xiang-mi LI~2 Yi-feng ZHOU~(2,3,4.2 Hefei National laboratory for Physical sciences at Microscale and School of Life Science,University of Science and Technology of china,Hefei 230027,china 3 laboratory of visual information processing,institute of biophysics,chinese academy of sciences,beijing {14.,china Hefei National laboratory for Physical sciences at Microscale and School of Life Science University of Science and Technology of China Hefei China laboratory of visual information processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Aim:To investigate the effect of chronic morphine exposure on the receptive fieldproperties of lateral geniculate nucleus(LGN)neurons in ***:Catswere injected with morphine(10 mg/kg)or saline twice daily,for 10 ***,extracellular single-unit recording techniques were used to examine the sensitivityof LGN neurons to visual stimuli in chronic morphine-treated and ***:Compared with saline-treated cats(as controls),LGN neurons inmorphine-treated cats had decreased signal-to-noise ratios(1.9 vs 3.1 ),and orien-tation and direction sensitivity(0.103 vs O.135 and 0.074.vs O.10,respectively),accompanied by significant increases in spontaneous(27.4.vs 17.5)and evokedactivity(preferred:4..2 vs 38.1;average:28.1 vs 22.3).Conclusion:Chronic mor-phine exposure can lead to the functional degradation of LGN neurons in cats,which might result from the effects of chronic morphine exposure on inhibitoryneurotransmission.

关键词： direction sensitivity orientation sensitivity signal-to-noise ratio spontaneous response evoked response

Binaurality and azimuth tuning of neurons in the auditory cortex of the big brown bat

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chinese Science Bulletin 2002年第12期47卷 1024-1027页

作者： SHEN Junxian & CHEN QicaiCenter for Brain and Cognitive Science, laboratory of visual information processing, {4. of biophysics, chinese academy of sciences, beijing 100101, china Department of Biology, Central china Normal University, Wuhan 4.0070, Lab. of visual Info. processing Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

By using a combined closed and free-field stimulation system, binaurality and azimuth tuning of the neurons in the auditory cortex of the big brown bat, Epte-sicus fuscus, were studied. A variety of azimuth-tuning functions were demonstrated for the binaural neurons. The large majority of EE (contralateral and ipsilateral excitatory) neurons exhibited azimuth selectivity with the best azimuths (BA) at contralateral 30°-4.°, some at ipsilateral 20°-4.° and preferred azimuth ranges (PAR, response amplitude >75% of maximum) between 8° and 4.°. Sound source azimuths strongly modulate spike counts with a mean modulation depth of 83.8% for EE neurons. EI (contralateral excitatory and ipsilateral inhibitory) neurons have simple azimuth tuning with BA located at contralateral 20°-4.° and a broad PAR ranged from 30° to 55°. The present results suggest that azimuth-tuning characteristics of binaural neurons in the auditory cortex of the bat are of significance for acoustic behaviour.

关键词： bat auditory cortex binaural neurons azimuth tuning.

The universal fuzzy logical framework of neural circuits and its application in modeling primary visual cortex

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Science china(Life sciences) 2008年第10期51卷 902-912页

作者： HU Hong1, LI Su2, WANG YunJiu2, QI XiangLin2 & SHI ZhongZhi1 1 Key laboratory of Intelligent information processing, institute of Computing Technology, {4. academy of sciences, beijing 100080, china 2 laboratory of visual information processing, institute of {14., {4. academy of sciences, beijing 100101, china Key laboratory of Intelligent information processing Institute of Computing Technology Chinese Academy of Sciences Beijing China laboratory of visual information processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Analytical study of large-scale nonlinear neural circuits is a difficult task. Here we analyze the function of neural systems by probing the fuzzy logical framework of the neural cells' dynamical equations. Al- though there is a close relation between the theories of fuzzy logical systems and neural systems and many papers investigate this subject, most investigations focus on finding new functions of neural systems by hybridizing fuzzy logical and neural system. In this paper, the fuzzy logical framework of neural cells is used to understand the nonlinear dynamic attributes of a common neural system by abstracting the fuzzy logical framework of a neural cell. Our analysis enables the educated design of network models for classes of computation. As an example, a recurrent network model of the primary visual cortex has been built and tested using this approach.

关键词： nonlinear dynamical system fuzzy logic visual cortex

Seasonal patterns of spatial differentiation of landcover change in china

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chinese Science Bulletin 1999年第4期44卷 362-364页

作者： CHEN YufengState Key laboratory of Resource and Environment information System , institute of Geography, chinese {4. of sciences, beijing 100101, china State Key laboratory of Resource and Environment information System Institute of Geography Chinese Academy of Sciences Beijing China

Using the 1°×1° NOAA AVHRR NDVI data set in china, an index on the spatial different gradient of landcover is created. Then based on the index and supported by the geographical information system, it is revealed through principal component and factor analyses methods that there exist four types of seasonal patterns of spatial differentiation of landcover change in china, i.e. November to next March type, June to September type, May or October type and April type.

关键词： landcover spatial differentiation seasonal pattern.

Influence of prolonged optic flow stimuli on spontaneous activities of cat PMLS neurons

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chinese Science Bulletin 2003年第8期48卷 786-790页

作者： XU Ying, LI Bing & DIAO Yuncheng laboratory of visual information processing, {4. of biophysics, chinese academy of sciences, beijing 100101, china Correspondence should be addressed to Li Bing (e-mail: lib@sun5.ibp. ***) laboratory of visual information processing Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

Changes in neuronal spontaneous activities after prolonged optic flow stimulation (using the three basic flow modes: translation, radiation and rotation) were inves-tigated by extracellular single-unit recording in cortical area PMLS of the cat. The results showed that the evoked re-sponses decreased with the prolongation of visual stimuli, and the spontaneous activities usually dropped to a lower level after the stimuli were withdrawn. Generally, the reduc-tion in spontaneous activities was larger after adaptation in the preferred direction than in the non-preferred direction. This difference was much pronounced to translation stimuli, but relatively insignificant to radiation and rotation. These points suggest that non-specific fatigue may act as the key factor in adaptation to simple translation, while some kinds of more complicated, direction-specific mechanism may be involved in adaptation to the complex optic flow patterns. In addition, PMLS may play an important role in perception and adaptation to complex motion and the relevant motion after-effects.

关键词：光流刺激自发性活动 PMLS神经细胞猫

A mixed finite element method for the unilateral contact problem in elasticity

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Science china Mathematics 2006年第4期49卷 513-524页

作者： HUA Dongying & WANG Lieheng The First Fundamental Department, beijing information Technology institute, beijing 100101,{4. institute of Computational Mathematics and Scientific/Engineering Computing, academy of Mathematics and System sciences, chinese academy of sciences, beijing 100080,{4. The First Fundamental Department Beijing Information Technology Institute Beijing China institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

In this paper, we provide a new mixed finite element approximation of the variational inequality resulting from the unilateral contact problem in elasticity. We use the continuous piecewise P2-P1 finite element to approximate the displacement field and the normal stress component on the contact region. Optimal convergence rates are obtained under the reasonable regularity hypotheses. Numerical example verifies our results.

关键词： unilateral contact problem, mixed finite element method.

A prototype auto-human support system for spatial analysis

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Progress in Natural Science:Materials International 2006年第9期16卷 954-966页

作者： LI Lianfa and WANG Jinfeng (State Key laboratory of Resources & Environmental information System, institute of Geographical sciences & Natural Resources Research, {4. academy of sciences, beijing 100101, china) State Key laboratory of Resources and Environmental information System Institute of Geographical Sciences and Natural Resources Re-search Chinese Academy of Sciences Beijing 100101 China

Spatial analysis is a multidisciplinary field that involves multiple influential factors, variation and uncertainty, and modeling of geospatial data is a complex procedure affected by spatial context, mechanism and assumptions. In order to make spatial modeling easier, some scholars have suggested a lot of knowledge from exploratory data analysis (EDA), specification of the model, fitness and diagnosis of the model, to interpretation of the model. Also an amount of software has improved some functionalities of spatial analysis, e. g. EDA by the dynamic link (GeoDa) and robust statistical calculation (R). However, there are few programs for spatial analysis that can automatically deal with unstructured declarative issues and uncertainty in machine modeling using the domain knowledge. Under this context, this paper suggests a prototype support system for spatial analysis that can automatically use experience and knowledge from the experts to deal with complexity and uncertainty in modeling. The knowledge base component, as the major contribution of the system, in support of the expert system shell, codes and stores declarative modeling knowledge, e.g. spatial context, mechanisms and prior knowledge to deal with declarative issues during the modeling procedure. With the open architecture, the system integrates functionalities of other components, e.g. GIS’ visualization, DBMS, and robust calculation in an interactive environment. An application case of spatial sampling, design and implementation of spatial modeling with such a system is demonstrated.

关键词： spatial analysis automatic support system modeling of spatial data artificial inference for modeling.

配对螺旋样纤维(PHF)-Tau与神经细胞的死亡

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生物化学与生物物理进展 2001年第4期28卷 441-443页

作者：聂春来视觉信息加工开放实验室

神经纤维缠结 (neurofibrillarytangles ,NFT)是老年性痴呆病的重要病理特征 ,人类神经tau分子聚集形成的配对螺旋样纤维 (pairedhelicalfilaments ,PHF)是NFT的主要成分 .最近研究表明 ,PHF与神经细胞的坏死和程序化死亡密切相关。

关键词：神经tau 氧自由基配对螺旋样纤维老年性痴呆病神经细胞死亡