轻度认知障碍患者脑皮层多特征分析与分类

揭示稳定型轻度认知障碍患者、转化型轻度认知障碍患者与健康正常人之间的脑结构及其形态变化差异,以区分3组人群.首先,选择73例健康正常人、46例稳定型MCI患者和40例转化型MCI患者,采集基线期以及1年和2年时间节点的脑结构磁共振图像;然后,应用Freesurfer软件计算皮层厚度、灰质体积、表面积和平均曲率等脑皮层形态结构特征,并分别利用T检验方法、稀疏约束降维法和递归特征消去法,选择重要特征;最后,利用线性支持向量机对3组人群进行分类,分析具有强分类能力的重要脑区及其分布.结果表明,递归特征消去法的分类性能最优,稀疏约束降维法次之,T检验最差;4种皮层特征融合,尤其是基线与纵向变化特征融合,可显著提高分类性能.脑皮层结构特征及其随时间的变化信息,能被有效地应用于稳定型和转化型MCI患者的自动分类.     

维持性血液透析患者轻度认知功能障碍的研究

探讨了维持性血液透析（maintenance hemodialysis,MHD）患者轻度认知障碍（mild cognitive impairment,MCI）的特点。采用横断面研究方法,对40例维持性血液透析患者及38例健康对照者采用中文版蒙特尔认知估量表（Montreal Congitive Assessment,MoCA）进行认知功能评定。结果得出,维持性血液透析患者轻度认知障碍表现为多个领域,发生率高,与对照组比较,差异有统计学意义（P〈0.05）。轻度认知功能障碍是维持性血液透析患者一种常见的并发症,早期筛查、诊断,及时干预意义重大。     

丁苯酞对血管源性轻度认知障碍患者 认知功能及脑血流量的影响

目的观察丁苯酞治疗血管源性轻度认知障碍患者的疗效及其对认知功能及脑血流量的影响.方法选取92例血管源性轻度认知障碍患者作为研究对象,采用系统抽样法将患者分为对照组和研究组,每组46例.给予对照组患者吡拉西坦治疗,给予研究组患者丁苯酞治疗,对两组患者的临床疗效、不良反应、治疗前后认知功能及脑血流速度进行观察分析.结果两组患者疗效比较研究组优于对照组(P0.05);两组患者的不良反应比较差异无统计学意义(P0.05);两组患者治疗前认知功能及脑血流速度比较差异无统计学意义(P0.05);两组患者治疗后认知功能及脑血流速度比较研究组优于对照组(P0.05).结论应用丁苯酞治疗血管源性轻度认知障碍,临床疗效明确.     

利用三维脑核磁共振图像与RBF核支持向量机检测人脑轻度认知障碍

为了及早检测轻度认知障碍(Mild Cognitive Impairment,MCI),降低阿尔茨海默病的患病率,文章提出一种基于径向基神经网络及核支持向量机(Radial Basis Function-kernel Support Vector Machine,RBF-kSVM)的MCI检测系统,该系统首先读取三维磁共振脑图像并预处理,然后通过主成分分析(Principal Component Analysis,PCA)降低特征维数,采用RBF核支持向量机作为分类模型,RBF的参数通过优化选择。实验数据采用OASIS公共数据库,选择50例正常对照组(Normal Control,NC)与50例MCI患者。十折交叉验证结果显示文中所提出方法的敏感度为84%、特异度为78%、准确度为81%,优于前向神经网络、决策树、支持向量机、齐次与非齐次核支持向量机方法。文中构建的RBF核支持向量机有效,可用于MCI检测。     

轻度认知功能障碍11C-PIB PET连续动态显像结果分析

 为探讨轻度认知功能障碍（MCI）患者碳-11标记的匹兹堡化合物B（11C-PIB）正电子放射断层摄影术（PET）显像的特点,评价MCI患者11C-PIB PET脑显像的临床价值,严格筛选3组受试者：MCI患者8例,阿尔茨海默病（AD）对照组6例,健康对照（HC）组7例。每位受试者均采用连续动态采集程序采集脑PET图像。通过视觉分析各组受试者的图像,总结成像特点。采用感兴趣区域（ROI）方法划取大脑皮层各叶和皮层下核团,得出各个脑区不同时间点的标准吸收值（SUV）,根据SUV绘出时间-放射性曲线。并选取45min时间点的SUV,计算出45min时各脑区与小脑的SUV比值并进行统计分析。结果发现,MCI组中一部分受试者PET图像特点与HC组相似;脑内放射性清除较快,而另外一部分受试者的脑内放射性清除则较慢。将MCI按照显像结果分为AD类似组及HC类似组进行分析后发现,AD类似组与AD组之间的清除率及脑区/小脑比值相比差异无统计学意义,而AD类似组与HC组之间的结果比较类似于AD组与HC组的比较结果。HC类似组与HC组之间的清除率及脑区/小脑比值相比差异无统计学意义,而HC类似组与AD组之间的结果比较则类似于HC组与AD组的比较结果。11C-PIB PET脑显像在不同MCI患者脑内的显像特点不同,因而有可能成为判断MCI预后的一种方法。     

脑室注射海人酸对大白鼠学习记忆行为的影响

大白鼠脑室注射海人酸(KA)5天后,检查被动回避行为和脑组织学变化。发现受注射一侧海马的背側CA3a分区锥体细胞破坏,对长时记忆,特别是长时记忆形成能力有严重损害,对学习和短时记忆无明显影响。增大KA剂量,对锥体细胞的破坏范围也扩大,能波及CA3,CA4和CAl区锥体细胞,双侧注射KA,两侧海马的背侧锥体细胞都有损毁,但对学习记忆行为的损害程度并不增高。这些结果提示,海马背侧CA3a分区锥体细胞在被动回避反应行为的长时记忆形成中有重要意义;长时记忆与学习和短时记忆的形成,在海马结构中可能有不同的神经基础,脑室注射KA后2月,海马锥体细胞的破坏仍未见恢复,长时记忆形成能力的受损亦未能代偿。本文还讨论了海马CA3影响长时记忆过程的可能神经机理。     

半夏泻心汤对衰老大鼠学习记忆能力的改善及分子机制

目的以D-半乳糖致衰老大鼠为动物模型,研究半夏泻心汤(BXT)对衰老大鼠学习记忆能力的改善及大脑海马区Ach、NE、DA、5-HT受体mRNA表达的影响,探究BXT对改善大鼠学习记忆能力的相关作用机制。方法结合Y型水迷宫测试的大鼠逃避潜伏时间,通过注射D-半乳糖建立老龄大鼠模型;随后将动物分为老龄对照组、石杉碱甲组、壮年对照组、BXT低剂量组、BXT中剂量组、BXT高剂量组,按组别不同进行灌胃给药。连续给药6周后,再次通过Y型水迷宫测试大鼠学习记忆能力改善情况,检测Ach、NE、DA、5-TH受体mRNA及抗体的表达,观察海马区病理学变化,由此探究BXT对衰老大鼠学习记忆能力改善的分子机制。结果与老龄对照组比较,在训练后24 h、48 h和96 h,各剂量BXT给药组均能明显缩短老龄大鼠逃避潜伏期。大鼠海马区组织HE染色显示,与老龄对照组相比,BXT高剂量组海马神经元损伤有所改善,但BXT中剂量组和低剂量组未见明显改善;免疫组化结果显示BXT高剂量组与老龄对照组相比,其椎体细胞染色数量多,排列紧密度好,细胞颜色较深。结论本研究发现BXT能改善老龄大鼠学习记忆能力,尤其是高剂量BXT改善效果最为明显,可能与增加老龄模型大鼠海马CHRM1、DRD2、HTR1a、ADRA2a mRNA的表达有关。     

基于格兰杰因果分析的MCI脑网络分类研究

使用静息态fMRI脑数据,构建了基于格兰杰因果分析的有向功能脑网络,对正常对照组和轻度认知障碍的早期和晚期进行识别。在特征选择部分,有向脑网络的局部属性和全局属性被施以双样本t检验,三组间具有显著差异的属性被选作分类特征;接着,支持向量机算法被应用于后续的分类。最后,运用单因素方差分析探测三组间两两均具有显著差异的脑区信息。实验结果表明,本研究取得了较好的分类效果,颞中回、楔前叶、海马旁回等许多脑区在3个考察组中均体现出了显著性差异,这与已有研究的结果基本一致。     

尼莫同联合脑蛋白水解物治疗非痴呆型血管性认知障碍的临床观察

目的:评价尼莫同和脑蛋白水解物注射液治疗非痴呆型血管性认知障碍(VCIND)的疗效。方法:将42例VCIND患者分为3组,各14例,A组口服尼莫同30 mg,tid;B组脑蛋白水解物注射液90 mg加入5%葡萄糖注射液(或0.9%氯化钠注射液)250 mL缓慢静滴qd;C组尼莫同30 mg,tid,联合脑蛋白水解物注射液90 mg加入5%葡萄糖注射液(或0.9%氯化钠注射液)250mL缓慢静滴qd,疗程均为14 d。2周治疗前后MoCA量表中文版及MMSE量表评分的变化,将结果进行统计学处理。结果:2周内,尼莫同联合脑蛋白治疗组治疗后MoCA量表中文版评分较治疗前有明显改善,且较其他组明显,差异有统计学意义(P<0.05)。单药治疗组治疗前后评分无显著改善,差异无统计学意义(P>0.05),而MMSE评分均无明显改善(P>0.05)。结论:按MoCA量表评定:尼莫同联合脑蛋白治疗非痴呆型血管性认知障碍疗效显著,优于单独使用尼莫同及脑蛋白。     

大鼠怀孕及哺乳期铅暴露致子鼠海马c-JUN表达的变化

通过观察大鼠怀孕期及哺乳期铅摄入致子鼠海马回c-jun的变化。用RT-PCR的方法分别检测大鼠怀孕期铅暴露后子鼠和母鼠哺乳期铅暴露后子鼠(子鼠出生早期经乳汁染铅后)脑海马组织的c-jun的变化。结果:大鼠怀孕早期和晚期铅暴露,子鼠出生2 d时海马的c-jun的表达明显受到抑制,出生后经哺乳低剂量铅暴露子鼠c-jun的表达受到明显抑制,而高剂量暴露的却增加了c-jun的表达,达对照组的3倍。子鼠出生4 d海马的c-jun的表达与对照组比较略高,且与出生2 d相比均有所增加。而出生后经哺乳高剂量铅暴露子鼠c-jun的表达依然明显高于对照组,达对照组的4倍。子鼠出生10 d海马的c-jun的表达较4 d时下降,但怀孕早期高剂量暴露组和晚期各暴露剂量均高于对照组。而出生后经哺乳暴露鼠c-jun的表达呈增多趋势,其中高剂量铅暴露子鼠c-jun的表达依然明显高于对照组,达对照组的近10倍。子鼠生后20 d时海马的c-jun的表达均显著增加,各剂量组呈现剂量效应,即随剂量增加表达增多,但表达量均低于对照组。结论:大鼠不同的铅暴露时间和强度对子鼠脑海马c-jun的表达变化不同,同时建立了RT-PCR的检测方法并在毒理学实验中进行了初步应用。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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