大学生对动态与静态面部表情限时加工的特点

目的:探究大学生对动态与静态面部表情图片限时加工的特点.方法:以18名大学生为被试,记录被试在动态或静态面部表情图片呈现的600 ms做出表情判断(生气、中性、高兴)的反应时和正确率,采用EGI-128导联脑电仪收集脑电数据,分析NI70、P200和晚正成分(LPC)3个脑电成分特点.结果:与动态呈现相比,被试对静态呈现的面部表情图片的反应时较短[(474.1±5.1) ms vs.(486.2±5.4) ms,P＜0.001],正确率较高[(0.83±0.02) vs.(0.79±0.02),P＜0.01].静态呈现时,N170成分表现出中性表情诱发的波幅小于生气表情和高兴表情[(-2.7±0.6)μv vS.(-3.3±0.7)μv,(-3.2±0.7)μv;P＜0.05],而高兴表情与生气表情诱发的波幅差异无统计学意义(P＞0.05).静态呈现时,P200成分表现出中性表情诱发的波幅小于生气表情和高兴表情[(3.3±0.5) μvvs.(4.0±0.6)μv,(3.8±0.6)μv;P＜0.05],高兴表情与生气表情诱发的波幅差异无统计学意义(P＞0.05).LPC的波幅与潜伏期的表情主效应显著(P＜0.05),生气表情诱发的波幅大于中性表情[(7.2±0.7) μv vs.(6.6±0.6)μv,P＜0.05];中性表情的潜伏期长于生气表情和高兴表情[(534.4±9.7)ms vs.(515.2±10.4) ms,(502.8±12.1)ms; P＜0.05].结论:本研究提示在限时条件下,早期阶段,静态呈现的表情加工比动态呈现的表情加工具有优势;到后期阶段,动态呈现的表情加工才能达到静态呈现的加工水平.     

标签发生在何时:情绪标签的ERP研究

目的:研究情绪标签的时间进程。方法:采用情绪标签的经典研究范式,结合事件相关电位技术(event-re-lated potential,ERP),让40名大学生完成情绪标签、性别标签、情绪匹配、性别匹配和观看等任务,并比较晚正成分(late positive potential,LPP)和P3波幅的差异。结果:1性别标签和观看条件LPP无显著差异;2与观看条件相比,情绪标签LPP波幅先上升后下降;3在400-450ms内情绪标签的P3波幅大于性别标签。结论:由于情绪的符号加工过程,情绪标签对情绪的调节作用可能呈现出先增强后减弱的动态过程。     

大学生心理理论错误信念任务的事件相关电位特点

目的:研究心理理论错误信念任务中信念推理和现实推理的脑电特点,对心理理论的脑机制进行初步探讨。方法:在天津师范大学方便选取23名大学生,采用NeuroScan公司64导脑电系统记录其执行图片错误信念任务时的事件相关电位(event-related potentials,ERP)和行为学结果,对被试在执行错误信念任务时分别进行的现实推理和信念推理的ERP结果进行分析,最终有效被试18名。结果:从刺激呈现后约300ms,信念推理和现实推理两种实验条件引起的事件相关脑电开始出现差异,600~900ms时间段内,在AF7[(2.34±2.71)vs.(1.32±2.97)]、FPz[(2.83±3.03)vs.(2.08±2.56)]、AF8[(3.75±2.64)vs.(2.76±2.34)]、T7[(1.31±2.77)vs.(0.68±3.54)]、Cz[(5.11±5.42)vs.(4.52±5.66)]、T8[(2.35±2.24)vs.(2.03±2.00)]及POz[(2.48±2.16)vs.(2.18±2.53)]电极上均表现为信念推理波幅正向大于现实推理波幅(P=0.065),此种差异接近有统计学意义,且主要分布于额叶电极。结论:对心理状态进行推理的神经机制与对现实进行推理的神经机制存在差别,心理理论能力与大脑额叶存在较为密切的关系。     

大学新生自杀意念对风险决策偏好影响的事件相关电位研究

目的:探讨有、无自杀意念的大学新生风险决策偏好的事件相关电位特征。方法:选取21例有自杀意念大学新生(男11例,女10例)和21例无自杀意念大学新生(男11例,女10例)完成仿真气球冒险任务(BART),根据BART值将个体的风险决策偏好(风险寻求/风险回避)分组。事件相关电位(ERP)指标包括P1、P2、FRN和P3脑电成分的平均波幅、峰峰值和潜伏期。结果:有自杀意念组的BART值大于无自杀意念组(P0.05)。ERP分析显示,风险寻求时,有自杀意念组P1成分的平均波幅大于无自杀意念组[(3.47±2.13)μv vs.(2.51±4.10)μv,P0.05];风险回避时,有自杀意念组P1、P2、P3成分的平均波幅均大于无自杀意念组[(5.71±3.29)μv vs.(4.10±4.18)μv,(9.51±3.67)μv vs.(6.26±4.20)μv,(8.47±4.99)μv vs.(5.79±5.34)μv;均P0.05],而FRN成分的平均波幅小于无自杀意念组[(8.37±4.17)μv vs.(5.10±6.24)μv,P0.01]。结论:本研究结果显示,有自杀意念的大学新生在风险决策方面更倾向于冒险。     

注意缺陷多动障碍儿童的内隐视觉空间注意特点

目的:探讨注意缺陷多动障碍(ADHD)儿童被动和主动内隐视觉空间注意特点.方法:选取符合美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)ADHD诊断标准的儿童25例,以及性别、年龄与之匹配的正常儿童18名.分别测试反映被动内隐视觉空间注意的pop-out视觉搜索任务及反映主动内隐视觉空间注意的线索-目标视觉搜索任务,比较两组反应时(RT)、正确率和个体内反应时标准差(ISD).结果:Pop-out视觉搜索任务中,ADHD儿童[(637.4±132.0) ms vs.(626.3±125.0) ms]和正常儿童[(635.5±131.1) ms vs.(626.6±138.5) ms]对左视野目标反应时均长于右视野(均P＜0.05),但是两组之间反应时、总体正确率差异无统计学意义(均P ＞0.05);正常儿童左视野正确率低于右视野[(92.3±9.4)％ vs.(94.5±8.1)％,P＜0.01],而ADHD儿童左右视野正确率差异无统计学意义[(91.9±7.4)％ vs.(90.7±7.5)％,P＞0.05],ADHD儿童ISD大于正常儿童[(185.4±48.0) ms vs.(137.5±36.7) ms,P＜0.01].线索-目标任务中,ADHD儿童和正常儿童对左视野的目标反应时均长于右视野[ADHD组,(641.1 ±94.2) ms vs.(629.1 ±83.1)ms;正常对照组,(626.3±128.6) ms vs.(614.9±133.1)ms;均P＜0.05],且线索提示有效目标反应时短于线索提示无效[ADHD组,(627.6±89.4) msvs.(654.3±84.6)ms,P＜0.01;正常对照组,(615.4±132.5) ms vs.(627.3 ±127.5) ms,P＜0.01];两组之间反应时和正确率差异无统计学意义,ADHD儿童ISD大于正常儿童[(200.1±46.8) ms vs.(147.8±32.8)ms,P=0.05].结论:与正常儿童相比,ADHD儿童无论是被动还是主动内隐视觉空间注意,其注意力状态均不稳定,波动性增大,注意力维持困难.     

抑郁个体情绪加工与认知控制的相互作用

目的:探讨抑郁个体情绪加工与认知控制的相互作用特点。方法:从重庆某两所高校120名学生中,用Beck抑郁问卷和自评抑郁量表筛选出20名抑郁情绪个体和26名正常被试参与情绪干扰任务。结果:两组被试在注视悲伤面孔时的正确率差异无统计学意义(P=0.115),而在忽视悲伤面孔时,抑郁情绪组的正确率低于正常对照组[(0.69±0.19)vs.(0.81±0.15),P=0.030];两组被试在注视高兴面孔时的正确率边缘显著(P=0.062),而在忽视高兴面孔时的正确率差异有统计学意义,抑郁情绪组的正确率低于正常对照组[(0.68±0.20)vs.(0.80±0.17),P=0.033]。呈现时间为500ms时的正确率高于呈现时间为250ms和375ms时的正确率[(0.75±0.03)vs.((0.68±0.03),(0.69±0.02);均P0.001],而呈现时间为250ms与375ms时的正确率差异无统计学意义(P=0.950)。结论:抑郁个体的情绪(不管正性还是负性)加工过程对认知控制过程会造成干扰,其认知控制功能可能受损;抑郁情绪个体的认知控制功能受损可能会引起正性情绪加工能力下降,而对负性情绪加工没有影响。     

有人际关系困扰的大学生的内隐心理活动

目的:探索有人际关系困扰(ID)问题的大学生在人际交往过程中的内隐心理活动特点,为ID者的心理辅导与干预治疗提供理论指导.方法:选取329名大学生,使用人际关系综合诊断量表(IRIDQ)将其分成ID组(IRIDQ得分为15～28分,n=43)、普通组(IRIDQ得分为9～ 12.11分,n=50)和无困扰组(IRIDQ得分为0～3.76分,n=50).采用GNAT (the Go/No-go Association Task)内隐联想范式和情绪STROOP范式测试三组在人际关系上的内隐认知、内隐情绪、内隐社交意向的反应时、击中率与虚报率(用于计算信号辨别率指数d’).结果:方差分析显示,在内隐认知、内隐情绪、内隐行为意向的平均反应时上,组别主效应均显著(均P ＜0.001),进一步多重比较发现,ID组积极内隐认知反应时长于普通组和无困扰组[(594.2±17.0) ms vs.(533.4±15.5) ms vs.(503.3±13.9) ms;均P＜0.01],而消极内隐认知反应时则短于普通组和无困扰组[(554.5±18.5) ms vs.(600.6±28.8) ms vs.(610.4±19.8)ms;均P＜0.01];ID组内隐情绪反应时长于普通组和无困扰组[积极情绪词(442.1±18.5) ms vs.(415.6±17.5) msvs.(395.7±12.9) ms;消极情绪词(434.3±17.5) ms vs.(390.1±13.1) ms vs.(389.8±15.5) ms;均P＜0.01]; ID组内隐社交意向反应时长于普通组和无困扰组[(593.6±10.7) ms vs.(395.6±12.0) ms vs.(381.2±8.1) ms;均P＜0.01],而社交情境d'最短[(0.8±0.6)vs.(1.8±0.8)vs.(2.2±0.6);均P ＜0.05)].结论:人际关系有困扰者存在消极的自我内隐认知和情绪干扰,人际交往行为有退缩意向.     

单胺氧化酶A基因单核苷酸多态性与抑制控制的关系

目的:考察青年人单胺氧化酶A(MAO A)基因标签单核苷酸多态性(tag-SNP)与抑制控制的关系。方法:纳入57名健康大学生,采用事件相关电位(ERPs)技术采集Go/Nogo任务范式下行为学数据(反应时、正确率)和反映抑制控制成分的N2/P3差异波的波幅及潜伏期。连接酶特异检测反应(LDR法)测定被试MAO A基因rs5906957、rs2235186、rs1181275和rs58524323等tag-SNP位点,根据各位点基因型将被试分别分为不同基因型组,考察各位点SNP基因型与脑电各成分的关系。结果:Rs2235186位点CT组P3差异波幅较CC组与TT组大[Cpz电极位点(3.3±2.6)μv vs.(0.7±2.8)μv vs.(2.2±2.5)μv,P0.05)]。Rs1181275位点P3差异波组间和脑区存在交互效应,简单效应分析显示CT组中部脑区差异波波幅较CC组和TT组大[Cpz电极位点(3.1±2.5)μv vs.(1.5±2.8)μv vs.(2.0±2.7)μv,P0.05]。结论:研究提示MAO A基因某些单核苷酸多态性与青年人认知加工的抑制控制过程相关。     

注意分散情绪调节的晚期正电位

目的:从Gross的情绪过程模型出发,利用双任务范式研究在情绪产生过程中注意分散是否调节晚期正电位(late positive potential,LPP).方法:招募20名大学生(9男/11女),从中国情感图片系统选择正性、中性和负性情境图各29张为刺激,采用默数和深呼吸为注意分散任务,记录和测量情绪状态强度和事件相关电位数据.结果:默数、深呼吸条件下所评价的情绪状态强度显著小于看条件.LPP波幅在早期(350-650 ms)、中期(650-1050 ms)和晚期(1050-1500ms)窗口呈现出不同的任务与图片效价交互作用.从350 ms开始,默数条件下三种图片的LPP波幅低于看条件;深呼吸条件下负性图片的LPP波幅低于看条件,但在晚期窗口正性和中性图片的LPP波幅与看条件无差异.结论:注意分散不仅有效降低被试的主观情绪状态强度,而且能够调节LPP波幅,是有效的情绪调节策略,但默数和深呼吸对不同效价的图片呈现出不同的时间过程模式.     

孤独症儿童对静态和动态视向提示信息的加工

目的:探索在静态和动态呈现条件下孤独症儿童对视向提示信息加工的特征.方法:选取符合美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)孤独症诊断标准的儿童和年龄性别匹配的正常对照儿童各10名.通过l张图片形成的静态视向提示和5张图片形成的动态视向提示,采用2(组别:孤独症儿童,正常儿童)×2(呈现方式:静态,动态)×2(提示性:有效提示,无效提示)的重复测量方差分析,比较两组儿童在不同呈现方式下的视向提示反应的正确率和反应时.结果:在静态条件下,孤独症儿童识别视向的正确率低于正常对照组儿童[(94.8±1.3)％vs.(99.5±1.3)％,P＜0.05],且反应时较长[(470.2±23.8) ms vs.(389.2±23.8) ms,P＜0.05];在动态条件下,有效提示的识别正确率高于无效提示[(98.8±0.5)％vs.(93.8±0.3)％,P＜0.05],且有效提示的反应时短于无效提示[(463.1±19.7) ms vs.(504.8 ±21.4) ms,P＜0.01],孤独症儿童的反应时长于正常对照组儿童[(544.6±28.4) ms vs.(423.3±28.4) ms,P＜0.05].结论:本研究发现提示孤独症儿童存在与正常儿童一样的视向注意转移,并无特异性视向注意损伤,孤独症儿童对动态视向信息加工可能较静态视向信息加工更敏感.     

量子点荧光标记应用于生物学的研究进展

量子点标记作为一种新型的荧光标记方法,应用于生物学领域的研究有其不可比拟的优势,短短数年在生物化学、细胞生物学、免疫化学等学科的研究中显示了它的巨大发展潜力。本文就量子点优于传统有机荧光染料的性质、量子点标记近年来在生物领域中的研究进展和应用前景作一阐述。     

Multi-focus cluster labeling

Document collections resulting from searches in the biomedical literature, for instance, in PubMed, are often so large that some organization of the returned information is necessary. Clustering is an efficient tool for organizing search results. To help the user to decide how to continue the search for relevant documents, the content of each cluster can be characterized by a set of representative keywords or cluster labels. As different users may have different interests, it can be desirable with solutions that make it possible to produce labels from a selection of different topical categories. We therefore introduce the concept of multi-focus cluster labeling to give users the possibility to get an overview of the contents through labels from multiple viewpoints.The concept for multi-focus cluster labeling has been established and has been demonstrated on three different document collections. We illustrate that multi-focus visualizations can give an overview of clusters along axes that general labels are not able to convey. The approach is generic and should be applicable to any biomedical (or other) domain with any selection of foci where appropriate focus vocabularies can be established. A user evaluation also indicates that such a multi-focus concept is useful.     

Ingredient and labeling issues associated with allergenic foods

Foods contain a wide range of food ingredients that serve numerous technical functions. Per capita consumer exposure to most of these food ingredients is rather low with a few notable exceptions such as sugar and starch. Some food ingredients including edible oils, hydrolyzed proteins, lecithin, starch, lactose, flavors and gelatin may, at least in some products, be derived from sources commonly involved in IgE-mediated food allergies. These ingredients should be avoided by consumers with allergies to the source material if the ingredient contains detectable protein residues. Other food ingredients, including starch, malt, alcohol and vinegar, may be derived in some cases from wheat, rye or barley, the grains that are implicated in the causation of celiac disease. If these ingredients contain gluten residues, then they should be avoided by celiac sufferers. A few food ingredients are capable of eliciting allergic sensitization, although these ingredients would be classified as rarely allergenic. These ingredients include carmine, cochineal extract, annatto, tragacanth gum and papain. Food manufacturers should declare the presence of allergenic food ingredients in the ingredient listings on product labels so that allergic consumers can know to avoid these potentially hazardous products.     

Desiderata for product labeling of medical expert systems

The proliferation and increasing complexity of medical expert systems raise ethical and legal concerns about the ability of practitioners to protect their patients from defective or misused software. Appropriate product labeling of expert systems can help clinical users to understand software indications and limitations. Mechanisms of action and knowledge representation schema should be explained in layperson's terminology. User qualifications and resources available for acquiring the skills necessary to understand and critique the system output should be listed. The processes used for building and maintaining the system's knowledge base are key determinants of the product's quality, and should be carefully documented. To meet these desiderata, a printed label is insufficient. The authors suggest a new, more active, model of product labeling for medical expert systems that involves embedding `knowledge of the knowledge base', creating user-specific data, and sharing global information using the Internet.     

壳聚糖载基因纳米粒子荧光标记的优化研究

目的研究荧光素异硫氰酸酯（FITC）与壳聚糖反应的主要影响因素，观察荧光标记对纳米粒子表征和转染效率的影响，以期建立一种快速、稳定并且适宜壳聚糖纳米载体示踪的荧光标记方法。方法FITC与壳聚糖在不同反应物比例、溶液pH及温度条件下反应，纯化并收获产物，计算其标记效率。采用复凝聚法制备荧光标记的壳聚糖载基因纳米粒子，并检测其表征及对Hela细胞转染效率。结果在该实验中，标记效率随着pH增大而增加，弱碱性（pH 7．5）时最佳；随着反应温度的升高，标记效率也随之上升；标记效率还随FITC添加的比例增大而升高。壳聚糖纳米粒子表征和转染效率实验显示最佳的壳聚糖标记条件是反应物壳聚糖与FITC的添加比例为25：1，在pH7．5、室温25℃条件下反应4h。结论优化的壳聚糖荧光标记方案的标记率比以前文献报道的方法高近3倍，用标记的壳聚糖制备的基因纳米粒子粒径及细胞转染效率与未标记壳聚糖制备的纳米粒子相近，可以达到较好的示踪效果。     

质粒DNA荧光修饰方法的研究

目的 研究一种质粒DNA荧光标记的简便方法,以便进行DNA递送的示踪.方法 质粒经 溴激活后,于不同温度下存放不同时间,再与1,10-二氨基葵烷形成氨基衍生物.氨基修饰质粒与荧光素异硫氰酸酯( FITC)反应,制备出荧光标记的质粒,纯化并收集产物,计算其标记效率,评估溴激活质粒在不同温度下存放不同时长对标记反应的影响;观察荧光标记对质粒转染效率的影响,并用激光共聚焦显微镜观察和流式细胞仪检测示踪效果.结果 实验数据显示溴活化的质粒随存放时间的延长标记效率反而下降,存放4℃较室温(25℃)的标记效率更高,提示溴活化质粒不适宜存放;而与没有标记的质粒相比,荧光标记的质粒对转染效率几乎没有影响.荧光标记的质粒应用于流式细胞仪检测和激光共聚焦显微观察都取得了较好的示踪效果.结论 本研究建立了一种荧光标记质粒DNA的简便方法,并且在基因递送的示踪实验中获得了较好的效果.     

Optimization of magnetosonoporation for stem cell labeling

Recent advances in magnetic cell labeling have taken place with the development of a magnetosonoporation (MSP) technique. The aim of this study was to optimize the MSP protocol in order to achieve high cell viability and intracellular uptake of MR contrast agents. First, we determined the sub‐optimal MSP parameters by evaluating the viabilities of C17.2 neural stem cells without Feridex using various MSP intensities ranging from 0.1 to 1 w/cm², duty cycles at 20%, 50% or 100%, and exposure times from 1–15 min. The sub‐optimized MSP parameters with cell viabilities greater than 90% were further optimized by evaluating both cell viability and intracellular iron uptake when Feridex was used. We then used the optimized MSP parameters to determinate the optimal concentration of Feridex for magnetic cell labeling. Subsequently, we validated the feasibility of using MRI to track the migration of neural stem cells from the transplanted sites to glioma masses in four mouse brains when the cells had been labeled with Feridex using the optimized MSP protocol. The MRI findings were confirmed by histological correlations. In vitro experiments demonstrated that the optimal MSP protocol was achieved at 20% duty cycle, 0.3 w/cm² ultrasound intensity, 5‐min exposure time and 1mg/mL Feridex. This study demonstrated that the optimized MSP cell labeling technique can achieve both high cell viability and intracellular uptake of MR contrast agents, and has the potential to be a useful cell labeling technique to facilitate future clinical translation of MRI‐integrated cell therapy. Copyright © 2010 John Wiley & Sons, Ltd.     

Background suppression in arterial spin labeling MRI with a separate neck labeling coil

In arterial spin labeling (ASL) MRI to measure cerebral blood flow (CBF), pair-wise subtraction of temporally adjacent non-labeled and labeled images often can not completely cancel the background static tissue signal because of temporally fluctuating physiological noise. While background suppression (BS) by inversion nulling improves CBF temporal stability, imperfect pulses compromise CBF contrast. Conventional BS techniques may not be applicable in small animals because the arterial transit time is short. This study presents a novel approach of BS to overcome these drawbacks using a separate 'neck' radiofrequency coil for ASL and a 'brain' radiofrequency coil for BS with the inversion pulse placed before spin labeling. The use of a separate 'neck' coil for ASL should also improve ASL contrast. This approach is referred to as the inversion-recovery BS with the two-coil continuous ASL (IR-cASL) technique. The temporal and spatial contrast-to-noise characteristics of basal CBF and CBF-based fMRI of hypercapnia and forepaw stimulation in rats at 7 Tesla were analyzed. IR-cASL yielded two times better temporal stability and 2.0-2.3 times higher functional contrast-to-noise ratios for hypercapnia and forepaw stimulation compared with cASL without BS in the same animals. The Bloch equations were modified to provide accurate CBF quantification at different levels of BS and for multislice acquisition where different slices have different degree of BS and residual degree of labeling. Improved basal CBF and CBF-based fMRI sensitivity should lead to more accurate CBF quantification and should prove useful for imaging low CBF conditions such as in white matter and stroke.     

Pulse-chase analysis of procollagen biosynthesis by azidohomoalanine labeling

Disruptions in procollagen synthesis, trafficking and secretion by cells occur in multiple connective tissue diseases. Traditionally, these disruptions are studied by pulse-chase labeling with radioisotopes. However, significant DNA damage, excessive accumulation of reactive oxygen species and formation of other free radicals have been well documented in the literature at typical radioisotope concentrations used for pulse-chase experiments. Therefore, it is important to keep in mind that the resulting cell stress response might affect interpretation of the data, particularly with respect to abnormal function of procollagen-producing cells. In this study, we describe an alternative method of pulse-chase procollagen labeling with azidohomoalanine, a noncanonical amino acid that replaces methionine in newly synthesized protein chains and can be detected via highly selective click chemistry reactions. At least in fibroblast culture, this approach is more efficient than traditional radioisotopes and has fewer, if any, unintended effects on cell function. To illustrate its applications, we demonstrate delayed procollagen folding and secretion by cells from an osteogenesis imperfecta patient with a Cys substitution for Gly766 in the triple helical region of the α1(I) chain of type I procollagen.     

微量核酸样品的双重限制性荧光标记技术

目的采用双重限制性荧光标记技术(doub le restriction fluorescent labeling,DRFL)标记微量核酸样品,提高基因芯片用于病原体检测的灵敏度。方法以限制性显示技术处理SARS-CoV核酸样品,分别采用传统限制性荧光标记技术(直接采用荧光标记的通用引物标记)和双重限制性荧光标记技术(荧光标记的通用引物和荧光标记的dNTP的双重荧光标记)标记,进一步在同等条件下与基因芯片进行杂交、清洗和芯片扫描检测。通过对杂交结果的分析,比较2种标记方法的标记效果。结果以DRFL方法标记SARS基因片段,其荧光强度均值比传统荧光标记方法提高了3.5835倍。结论DRFL技术有效地提高单位分子标记片段的荧光强度值,提高了检测的灵敏度,可用于微量病原体核酸样品的基因芯片检测。