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Neuroscience Bulletin 2015年第3期31卷 317-330页

作者： Fernando Marmolejo-Ramos Kim Hellemans Amy Comeau Adam Heenan Andrew Faulkner Alfonso Abizaid Amedeo D'Angiulli Department of Psychology Stockholm University Department of Neuroscience Carleton University Department of Psychology Queens UniversityKingston Institute of Interdisciplinary Studies Carleton University

Although food and affective pictures share similar emotional and motivational characteristics, the relationship between the neuronal responses to these stimuli is unclear. Particularly, it is not known whether perceiving and imagining food and affective stimuli elicit similar event-related potential （ERP） patterns. In this study, two ERP correlates, the early posterior negativity （EPN） and the late positive potential （lpp） for perceived and imagined emotional and food photographs were investigated. Thirteen healthy volunteers were exposed to a set of food photos, as well as unpleasant, pleasant, and neutral photos from the International Affective Picture System. In each trial, participants were first asked to view a photo （perception condition）, and then to create a visual mental image of it and to rate its vividness （imagery condition）. The results showed that during perception, brain regions corresponding to sensorimotor and parietal motivational （defensive and appetitive） systems were activated to different extents, producing a graded pattern of EPN and lpp responses specific to the photo content - more prominent for unpleasant than pleasant and food content. Also, an EPN signature occurred in both conditions for unpleasant content, suggesting that, compared to food or pleasant content, unpleasant content may be attended to more intensely during perception and may be represented more distinctly during imagery. Finally, compared to LLP activation during perception, as well as imagery and perception of all other content, lpp activation was significantly reduced during imagery of unpleasant photos, suggesting inhibition of unwanted memories. Results are framed within a neurocognitive working model of embodied emotions.

关键词： food emotion perception mentaimagery ERP EPN lpp vividness InternationaAffective Picture System embodiment

Experimental investigation of laser-produced-plasma EUV source based on liquid target

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光学精密工程 2005年第5期13卷 604-607页

作者： QI Li-hong NI Qi-liang CHEN Bo Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China Institute of Atomic and Molecular Physics Jilin University Changch un 130026 China

A laser-produced plasma(lpp) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the lpp source's radiation with ethanol and acetone target respectively was measured by an AXUV100 silicon photodiode combined with a McPHERSON model 247 grazing incidence monochromator of the resolution Δλ≤0.075 nm and the wavelength scanning interval 0.5 nm. Both ethanol and acetone target lpp source had EUV emission at 11～20 nm wavelength. The comparison between the spectra of the two kinds of target materials shows that all the two kinds of target source's spectra are the result of oxygen ions' transitions under current source's parameters, but the spectrum intensity from different target sources is different. The spectra intensity from the ethanol target is higher than that from the acetone target. In addition, the target liquid is forced into the vacuum chamber by the background pressure supported by the connected external high pressure gas, and the influence of the background pressure on the source's intensity is investigated.

关键词： lpp 激光等离子体亮度

Multi-radius centralized binary pattern histogram projection for face recognition

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Chinese Optics Letters 2009年第6期7卷 475-478页

作者：付晓峰韦巍 Institute of Computer Hangzhou Dianzi University Institute of Electrical Engineering Zhejiang University

The existing local binary pattern （LBP） operators have several disadvantages such as rather long histograms, lower discrimination, and sensitivity to noise. Aiming at these problems, we propose the central- ized binary pattern （CBP） operator. CBP operator can significantly reduce the histograms＇ dimensionality, offer stronger discrimination, and decrease the white noise＇s influence on face images. Moreover, for in- creasing the recognition accuracy and speed, we use multi-radius CBP histogram as face representation and project it onto locality preserving projection （lpp） space to obtain lower dimensional features. Experiments on FERET and CAS-PEAL databases demonstrate that the proposed method is superior to other modern approaches not only in recognition accuracy but also in recognition speed.

关键词： LBP lpp CBP

Attentional negativity bias moderated by positive mood arousal

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Chinese Science Bulletin 2010年第19期55卷 2010-2015页

作者： CHEN ChunPing LUO YueJia Institute of Psychology Chinese Academy of SciencesBeijing 100101China Graduate School of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal UniversityBeijing 100875China

Automatically allocation of more attention to negative stimuli is called emotional negativity bias.An event-related potentials(ERPs) experiment investigated whether or not this bias was altered by positive mood arousal.The results suggested that the attention bias towards negative stimuli was attenuated when positive information was accessible.

关键词： negativity bias positive mood P2 lpp ERPs

Ion dynamics in ultrafast laser ablation of copper target

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Chinese Optics Letters 2013年第9期11卷 93-97页

作者：倪晓昌 Anoop K.K. Mario Bianco Salvatore Amoruso 王宣李彤胡明列宋振明 School of Electronic Engineering Tianjin University of Technology and Education Tianjin 300222 China CNR-SPIN and Dipartimento di Fisica Universita degli Studi di Napoli Federico II Complesso Universitario Monte S. Angelo Via Cintia Napoli 80126 Italy Ultrafast Laser Lab Key Laboratory of Opto-electronic Information Technology Ministry of Education (Tianjin University) Tianjin 300072 China Department and Institute of Physics School of Science. Tianjin Polytechnic University Tianjin 300387 China

We investigate the angular distribution and average kinetic energy of ions produced during ultrafast laser ablation （ULA） of a copper target in high vacuum. Laser produced plasma （lpp） is induced by irradiating the target with Ti：Sapphire laser pulses of -50 fs and 800 nm at an angle of incidence of 45°. An ion probe is moved along a circular path around the ablation spot, thereby allowing characterization of the time-of-flight （TOF） of ions at different angles relative to the normal target. The angular distribution of the ion flux is well-described by an adiabatic and isentropic expansion model of a plume produced by solid-target laser ablation （LA）. The angular width of the ion flux becomes narrower with increasing laser fluence. Moreover, the ion average kinetic energy is forward-peaked and shows a stronger dependence on the laser pulse fluence than on the ion flux. Such results can be ascribed to space charge effects that occur during the early stages of lpp formation.

关键词： Ion dynamics in ultrafast laser ablation of copper target ULA lpp

Differentiating electrophysiological response to decrease and increase negative emotion regulation

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Chinese Science Bulletin 2013年第13期58卷 1543-1550页

作者： WU HaiYan TANG Ping HUANG XuShu HU XiaoQing LUO YueJia State Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University Sichuan Research Center of Applied Psychology Chengdu Medical College Department of Psychology Northwestern University

We investigated the reappraisal and the time course of negative emotion regulation by performing event-related potential (ERP) recordings. We found that negative pictures elicited more positive P2 and late positivity potential (lpp) deflections than neutral pictures. This effect occurred between 150-2000 ms post-stimulus. Compared to the emotion maintaining condition, the emotion enhancing condition was associated with higher arousal ratings and displayed increased P2 and lpp amplitudes. The decrease condition was also associated with reduced picture-induced arousal; however, it led to increased P2 and lpp amplitudes. Furthermore, when compared with the maintain condition, both the enhancing and decrease conditions significantly enhanced lpp in the early stage (350-750 ms). Compared to previous studies using western subjects, the negative emotion lpp effects of the present study were shorter in duration and the decrease-emotion condition elicited larger lpps.

关键词：情绪调节电生理反应负性事件相关电位 lpp 时间过程早期阶段持续时间

lpp蛋白在大肠杆菌细胞壁表面分布规律研究

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Lpp蛋白在大肠杆菌细胞壁表面分布规律研究

作者：刘思敏山东大学

学位级别：硕士

外膜是革兰氏阴性菌重要的细胞结构,大肠杆菌最重要的用于稳定外膜结构的蛋白是布劳恩脂蛋白(Braun’s Lipoprotein,即lpp)。lpp是大肠杆菌中唯一一种能够通过共价结合的方式锚定在细胞壁肽聚糖层上的外膜脂蛋白。除lpp外,通过非共价键... 详细信息

外膜是革兰氏阴性菌重要的细胞结构,大肠杆菌最重要的用于稳定外膜结构的蛋白是布劳恩脂蛋白(Braun’s Lipoprotein,即lpp)。lpp是大肠杆菌中唯一一种能够通过共价结合的方式锚定在细胞壁肽聚糖层上的外膜脂蛋白。除lpp外,通过非共价键方式结合在肽聚糖层上的外膜蛋白Pal(Peptidoglycan associated lipoprotein,肽聚糖结合脂蛋白)和OmpA(Outermembrane protein A,外膜蛋白A)也发挥了维持外膜结构稳定的功能。lpp蛋白的数量水平必须维持在一个较为稳定的范围内,以使大肠杆菌获得最佳的生长状态,因此大肠杆菌会通过一种sRNA即MicL对细胞内的lpp数量进行调控。关于对lpp进一步的深入理解,依赖于对lpp在细胞壁上的分布的认识。本课题组前期研究中,探索出了使用原子力显微镜技术对细胞壁上的lpp的高分辨率直接观察的方法,为研究lpp在细胞壁上的分布规律奠定了坚实的基础。本论文在实验室已有工作的基础上,进一步对大肠杆菌生长、分裂、调控过程中lpp在细胞壁上的分布规律开展了研究,具体研究内容如下:1.lpp在大肠杆菌细胞壁上的分布本部分主要探究lpp在非分裂状态及分裂状态大肠杆菌细胞壁上的分布规律。研究结果发现lpp只分布在细胞壁肽聚糖层的外侧面上,内侧面没有lpp分布。在非分裂状态的大肠杆菌中,lpp在稳定期大肠杆菌细胞壁上的密度高于指数期的密度。在处于分裂状态的大肠杆菌中,缢缩环带处形成一个缺失lpp的沟壑状区域。这个沟壑状区域存在于菌体的整个分裂过程中,显示在野生型大肠杆菌中,lpp并不参与大肠杆菌分裂中的外膜拉拽过程。2.lpp在菌体分裂过程中的作用及其与Pal的功能关系构建缺失pal的突变株,研究在Δpal突变株中lpp在细胞壁表面的分布规律。在Δpal突变株中,处于分裂状态的细胞的缢缩环带处的沟壑状结构消失,lpp密集的分布在包括缢缩环带在内的整个细胞壁。进一步敲除掉lpp之后,ΔpalΔlpp突变株菌体的分裂能力受到抑制,说明lpp在Δpal突变株的分裂过程是具有贡献的。3.MicL对lpp在大肠杆菌细胞壁上分布的调控构建缺失MicL的突变株,研究在ΔmicL突变株中lpp在细胞壁表面的分布规律。研究结果显示,在ΔmicL突变株中细胞壁外侧表面的lpp数量高于野生型大肠杆菌,内侧面也出现lpp蛋白。我们发现铜离子也会引起lpp在肽聚糖层内侧面的异常定位。缺失MicL之后,受铜离子处理之后的大肠杆菌肽聚糖层内侧面的lpp分布显著增多,解释了缺失MicL(CutC)之后会增加大肠杆菌对铜离子敏感性的原因。4.lpp基因的分布及在不同类群细菌中的多样性通过生物信息学分析,发现lpp基因主要分布在变形菌门γ变形菌纲的肠杆菌目、弧菌目、气单胞菌目和交替单胞菌目中。选取三株基因组中含有lpp的肠杆菌目的Klebsiella michiganensis和Serratia marcescens、弧菌目的Vibriolentus,以及两株基因组中不含lpp的莫拉氏菌科的Prolinoborus fasciculus和冷单胞菌科的Psychromonas aquatilis进行观察研究。结果发现肠杆菌目的两株细菌细胞壁表面的颗粒结构与大肠杆菌高度一致,但弧菌目的一株细菌的细胞壁表面结构和大肠杆菌则差异较大。不含lpp基因的两株菌的细胞壁表面无任何可辨识的蛋白结构可以观察到。通过以上研究,揭示了 lpp在大肠杆菌细胞壁肽聚糖层表面的分布规律,并且发现了 lpp在分裂过程中所起到的作用,并且进一步发现了 MicL对lpp分布的影响,最后揭示了在其他细菌种类中细胞壁上lpp的形貌多样性。本论文的工作深化了对lpp的了解,并为进一步深入研究大肠杆菌生长和分裂机制提供了一定的依据。

关键词： lpp 分布规律分裂调控多样性

Experimental Study on 308nm Laser Interaction with Materials

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Plasma Science and Technology 2001年第3期3卷 827-834页

作者：赵学庆王立君徐建波谢永杰易爱平王龙华刘晋袁孝刘晶儒 Northwest Institute of Nuclear Technology Xi'an 710024 China

A 10 J, 4o us XeCl laser interaction with LY12 aluminum and optical glass K9 targets is reported. The properties of laser-produced plasma (lpp) are analyzed. As a result, some parameters such as plasma ignition thresh... 详细信息

关键词： lpp In Experimental Study on 308nm Laser Interaction with Materials 308

布氏脂蛋白lpp的长度对大肠杆菌生理功能的影响

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布氏脂蛋白Lpp的长度对大肠杆菌生理功能的影响

作者：杨培玲山东大学

学位级别：硕士

革兰氏阴性细菌在细胞结构上与革兰氏阳性细菌的一个显著差别,是其细胞壁的肽聚糖之外还具有一层外膜结构。稳定的外膜结构给革兰氏阴性细菌提供了一个稳定的周质空间,从而保证了周质空间中众多重要生命活动的正常进行。在大肠杆菌中,... 详细信息

革兰氏阴性细菌在细胞结构上与革兰氏阳性细菌的一个显著差别,是其细胞壁的肽聚糖之外还具有一层外膜结构。稳定的外膜结构给革兰氏阴性细菌提供了一个稳定的周质空间,从而保证了周质空间中众多重要生命活动的正常进行。在大肠杆菌中,布氏脂蛋白lpp是最主要的执行稳定外膜结构功能的蛋白之一。lpp蛋白分子量较小,结构上呈单股α螺旋,常以三聚体形式存在。lpp也是大肠杆菌中唯一一种能够共价连接到肽聚糖层上的外膜蛋白,其N端连接有三个脂肪酸分子并插入到外膜中,C端共价连接在细胞壁肽聚糖层上。一个大肠杆菌细胞中含有数十万个lpp分子,它们共同支撑起外膜,并且保证了外膜结构的稳定性。除此之外,lpp还参与了周质空间中一系列重要生命活动,如本课题组的前期研究证实,lpp在大肠杆菌的菌体分裂过程中也起到重要作用。为适应不同的生存环境,自然界中的细菌进化出了不同长度的lpp。lpp的长度直接影响到外膜和肽聚糖层之间的距离,进而影响到周质空间的高度。研究表明,延长和截短lpp蛋白长度之后,大肠杆菌的周质空间的高度就会随之发生变化,周质空间中的一些生命过程也会随之发生变化。如lpp长度的改变会影响到菌体的机械性质、改变周质空间重要蛋白复合物的装配、影响跨周质空间的信息传递等等。但是关于lpp的长度改变对细菌生理特征的影响还缺乏系统性研究。本论文在实验室已有工作的基础上,构建了具有不同长度lpp的大肠杆菌突变株,并且研究了 lpp长度改变后对大肠杆菌的生理功能的影响,具体研究内容如下:1.构建截短和增长lpp的大肠杆菌突变株构建了 lpp截短21个氨基酸残基和增长21个氨基酸残基的大肠杆菌lpp-21和lpp+21突变株。用AlphaFold2对改造后的lpp进行结构预测,初步判断构建的蛋白能够折叠成为正常的单股α螺旋构象。通过RT-qPCR检测构建的突变基因能够正常转录。提取突变株细胞壁肽聚糖层,使用原子力显微镜研究证实突变后的lpp蛋白能够正确定位并共价结合到肽聚糖层外侧面上。原子力显微镜下lpp-21突变株肽聚糖层上的lpp颗粒变小,可能由于lpp截短之后不易形成三聚体而造成。而且lpp-21突变株肽聚糖层上出现局部缺失lpp而形成的大量孔洞区域。2.lpp长度改造后对菌体形态及生长状态的影响以大肠杆菌野生型WT株和缺失lpp的Δlpp突变株为对照,发现在标准培养条件培养lpp长度改造后的大肠杆菌lpp-21和lpp+21突变株时,其生长曲线与WT株相似,说明突变株的生长并未受到显著影响。使用光学显微镜、透射电子显微镜、原子力显微镜等对突变株的菌体形貌进行了研究,证实突变株能够正常进行生长分裂,突变株菌体形态并未发生较大改变。但是lpp-21突变株会产生大量菌毛,推测有可能是由于大量菌毛的表达而造成了肽聚糖层上出现缺失lpp而形成的孔洞结构。3.lpp长度改造后对突变株生理状态和环境适应的影响lpp蛋白长度改变后,lpp-21和lpp+21突变株对NaCl浓度的耐受性出现一定程度下降。lpp-21突变株对EDTA的敏感性与WT株相似,但lpp+21突变株对EDTA非常敏感。lpp长度改变后,两种突变株对高压生长环境的耐受性都出现下降。lpp-21和lpp+21突变株的游动能力和群涌能力都弱于WT株;lpp-21突变株的生物被膜形成能力和WT株相仿,但lpp+21突变株的生物被膜形成能力增强。两种突变株对抗生素的耐受能力与WT株相仿,仅个别抗生素如Fosfomycin对lpp-21突变株的抑菌效果减弱。通过以上研究,揭示了 lpp蛋白长度改变后对大肠杆菌菌体形貌以及生理功能的影响。本论文的工作有助于深入理解lpp在维持大肠杆菌生理功能中的意义,并为后续lpp生理功能的进一步研究提供重要依据。

关键词： lpp 蛋白长度细胞壁菌体形貌生理影响