肌萎缩侧索硬化症在3.0T MR及弥散张量纤维束示踪技术上的表现

目的:探讨肌萎缩侧索硬化症(ALS)在3.0T MRI及弥散张量纤维束示踪技术(DTT)上的影像表现.方法:使用GE 3.0T MR,对病例组进行T1WI,T2WI,FLAIR及DTI扫描,分析其在常规MRI上的表现;进行DTT成像,分析纤维束的形态及连续性.结果:69例病例组中,脑萎缩患者35例,占50.7%;在FLAIR及T2WI上皮质脊髓束走行区高信号患者,27例,占39.1%;中央前回皮质下"黑线征"为21例,占30.2%;69例病例组皮质脊髓束在三维彩色编码张量图上颜色混杂,在弥散张量纤维束示踪图上呈FA值较低的绿色或蓝色;部分病例组(9例)双侧皮质脊髓束形态欠对称;部分病例组(12例)脑桥层面未见纤维束通过.结论:ALS患者的常规MRI表现阳性率低;三维彩色编码张量图通过三种颜色混杂提示纤维束走行方向紊乱;弥散张量纤维束示踪图可直观显示ALS患者纤维束的损害.     

融合白质功能信号的DWI纤维优化重建

磁共振弥散加权成像(DWI)可对大脑白质纤维束的结构连通性进行无创研究,其主要方法为DWI纤维重建.并且基于DWI的结构连接常常与基于功能磁共振成像的功能连接相结合,以得到纤维重建的最优路径.本文提出一种融合白质fMRI,将功能信号作为先验信息进行DWI纤维全局优化重建的方法,获得表征描述特定功能结构的最优纤维路径.实验结果表明,加入fMRI功能先验信息的优化方法可重建出具有功能意义的白质纤维束,较之现有的纤维重建方法具有更高的可靠性和鲁棒性.     

对称归一化配准的多图谱大脑扩散张量图像分割

基于磁共振T1成像的全脑区分割方法及其在临床上的应用已经有较为广泛的研究,磁共振扩散张量成像凭借其在脑白质神经纤维束成像上的优势,近年来围绕扩散张量成像的理论和应用研究发展很快,针对扩散张量成像的脑区分割研究就成为一个必须要解决的问题.图像配准是精确实现脑区分割的重要技术步骤,传统的配准方法未考虑到图像的形变大小对配准...     

基于FMT的扩散张量成像脑白质纤维跟踪算法

扩散张量成像及脑白质纤维跟踪技术是目前惟一采用的活体、无创、三维显示脑白质纤维的成熟方法.针对扩散张量成像的特点,运用快速行进法产生基于体素的联合函数,并通过反向跟踪重建了脑白质纤维.实验结果表明,反向跟踪有效地解决了纤维的分叉问题,速度函数的改进使得跟踪的效率明显提高,而且结果也更加符合解剖结构.该算法的提出很好地解决了目前临床DTI数据可视化中的难题.     

慢性酒精中毒性脑病磁共振及功能性成像分析

目的探讨慢性酒精中毒性脑病磁共振及功能性成像改变.方法总结32例慢性酒精中毒性脑病的患者,分别进行磁共振常规平扫、磁共振弥散成像、磁共振波谱成像分析.结果 32例患者均有不同程度的精神异常,表现为脑萎缩、脑白质脱髓鞘.磁共振弥散成像为高信号,表观扩散系数ADC图为低信号,磁共振波谱成像显示病变部位氮乙酰天门冬氨酸(NAA)以及胆碱(Cho)显著减低.结论磁共振及其功能性成像对酒精性脑病的诊断、判断治疗及预后评价具有重要价值.     

应用磁共振扩散张量成像对正常人脑白质各向异性的初步研究

目的 利用磁共振扩散张量成像(DTI)技术,研究正常人脑白质的各向异性的正常变化.方法 随机选择20例正常志愿者进行磁共振扩散张量成像,测定双侧内囊前后肢、内囊膝部、外囊、半卵圆中心及胼胝体膝部和压部的FA值,并进行统计学分析.结果 人脑白质中FA值在胼胝体、内囊、外囊、半卵圆中心间均有显著性差别(P＜0.05).胼胝体膝部与压部、内囊前后肢与膝部无显著性差别.结论 DTI技术可以清楚地显示脑白质的解剖结构,通过FA值,能较好地反映组织的各向异性的变化.     

卒中后失语症患者弓状纤维弥散张量成像研究

目的:运用弥散张量成像技术(DTI)对卒中后失语症患者大脑双侧弓状纤维束形态结构在语言康复治疗前后改变情况进行观察和分析,以期探讨大脑白质纤维结构在卒中后失语症恢复机制中的作用.方法:对1例卒中后失语症患者进行5个月的语言康复治疗,在治疗前后分别进行汉语失语成套测验(ABC)评估和DTI扫描,观察各语言功能亚项和大脑双侧弓状纤维束形态结构的改变,并分析各语言功能亚项改变与双侧弓状纤维束形态结构变化之间的关系.结果:经过5个月的语言康复治疗,患者ABC各语言分项治疗前后得分百分比为:听理解(治疗前66.38%,治疗后69.40%);命名(治疗前84.76%,治疗后84.76%);复述(治疗前64.00%,治疗后72.00%);口语表达(治疗前69.81%,治疗后81.13%),其中听理解和命名功能未见明显改善,而复述和口语表达改善较明显.在口语表达分项的各亚项中,信息量(治疗前66.67%,治疗后83.33%)和流利性(治疗前48.15%,治疗后66.67%)得分明显提高.复述分项中则以句复述亚项得分百分比提高为主,从治疗前的52.63%提高到63.16%.DTI纤维追踪结果显示患者双侧弓状纤维束的纤维数量和致密性增加并出现损伤部位的结构重建.结论:卒中后失语症患者经过语言康复治疗后大脑双侧弓状纤维束可发生完整性增加及结构重建等改变,这种改变可能参与语言功能的恢复.     

使用扩散张量成像数据重建脑白质纤维的新算法

由磁共振扩散张量成像（DT-MRI）可以获得扩散的方向性信息，利用这些信息可以无创地重建人脑的白质纤维，而且这也是目前在活体上重建脑白质纤维的唯一方法．然而由于磁共振成像设备与成像技术的限制，纤维重建过程中会遇到许多困难，例如：DT-MRI的数据是离散的，而所要重建的纤维是连续的；而且由相对较低的MRI空间分辨率所引起的部分容积效应会影响DT—MRI的数据质量．针对这些问题，提出了一种加权跟踪算法．该算法结合经典物理理论，利用纤维跟踪过程中待定方向点周围相关体元的主向量与分量各向异性（FA）值来计算纤维跟踪线的前进方向．实验表明，该算法能够相对较好地解决重建过程中所存在的困难．从重建的效果看，该方法能够很好地反映脑白质纤维的分布情况．     

早产儿脑损伤磁共振检查临床分析

目的:了解早产儿脑损伤的发生率及探讨磁共振检查对早产儿脑损伤的诊断价值。方法:对我院住院早产儿130例在生后1周内行头颅磁共振检查。结果:早产儿脑损伤的发生率为63.8%,以出血性病灶较多见(29.2%),其次为出血合并缺血性病灶(24.6%)。弥散加权成像对脑白质损伤较敏感,磁敏感加权成像对出血较敏感。结论:磁共振检查对早产儿脑损伤的诊断提供了准确的影像学依据。     

基于BEEI方法的软包装热封缺陷超声检测研究

将超声无损检测技术应用于软包装热封封口性能检测中,采用背散射回波包络积分(BEEI)成像方法,该方法将每一扫描点的时域回波信号进行Hilbert变换求其包络信号,将包络信号在整个回波时间段的积分值按照扫描的先后次序生成一个二维矩阵,对矩阵插值后进行成像.试验中,采用中心频率为22.66MHz的点聚焦探头,对软包装封口处直径为50—150μm的六种通道型缺陷和夹杂缺陷进行扫描,扫描区域为包含缺陷的2.98mm×1.50mm的矩形区;分析了成像矩阵中BEEI值的变异系数(CV)以及垂直于热封方向和平行于热封方向上BEEI值的变化趋势.结果表明,超声无损检测技术可以较好地应用于软包装热封质量的检测;试验所得的BEEI值的变异系数低于8%,说明整个成像矩阵中BEEI值的离散程度较小;缺陷区的BEEI均值高于背景区的BEEI均值约30%—40%.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with