右大脑半球巨大上皮样瘤1例

患者,男,40岁.在“脑囊肿”分流术后3年,因头痛、左侧肢体无力半年于1989年2月入院.病人3年前曾因头痛、左侧肢体无力,CT检查见右额顶颞区广泛低密度改变,初步诊断为“右侧额预颞区巨大脑囊肿”行脑囊肿腹腔分流术。术后症状缓解,能正常参加劳动。近半年来,再次出现头痛和左侧肢体无力而入院。体查:神清,双侧视乳头明显水肿,左侧肢体肌力3～4度,CT复查见原右额顶颞低密度区增大.于低密度区直接穿刺碘水造影,示病变区与脑室不相通.全麻下行右额顶颞开颅探查术,术中见有额顶颞区有一肿物,约7cm×7cm×5cm,边界清楚,包膜完整,内含豆腐渣样内容物;并发现原引流管置于脑室内。全部     

基于fNIRS的符号和非符号数量加工的脑机制研究

为探讨符号和非符号数量加工的特异性和非特异性问题以及二者间相互转换的神经机制,利用功能性近红外光谱成像技术(fNIRS)对30名成人进行测量,实验中让被试完成数量适应范式任务,结果发现:(1)非符号数量加工主要激活脑区为右顶上叶、右额上回和左右额中回,而符号数量加工则主要在左额中回有显著激活,且只有符号数量加工中出现了距离效应;(2)非符号向符号数量转换由左右顶上叶、左额上回和左右额中回负责,而符号向非符号数量转换则是由左顶上叶和左右额上回负责.研究结果既支持了符号和非符号数量加工的特异性观点,又进一步揭示符号和非符号数量相互转换有着不同的神经机制.     

自信与青少年社会适应的关系:清晰度的中介作用

以社会适应双功能模型为理论基础,考察自信与社会适应之间的关系,以及自信清晰度的中介作用.采用总体自信问卷、自信清晰度问卷和青少年社会适应状况量表对333名青少年进行测查,结果显示:自信能够预测青少年的积极/消极适应状况,但是自信对2种社会适应的预测力不同,表明自信与2种社会适应的关系紧密度不同;自信清晰度在自信与积极/消极适应之间的中介效应显著,但是对消极适应的中介效应大于积极适应,说明自信清晰度的中介功能也有差异.     

普洱生茶和熟茶的品质化学成分分析比较

以云南地区代表性普洱生茶和熟茶为研究对象,通过感官审评评价其汤色和滋味,采用分光光度计、高效液相色谱和测色仪等,分析比较生茶和熟茶的主要生化成分以及色泽的差异,利用相关性研究分析与普洱生茶和熟茶的色泽、滋味相关的主要生化成分.结果表明,除可溶性总糖、咖啡碱和茶黄素外,生茶和熟茶的游离氨基酸总量、茶多酚、黄酮醇类和酚酸类等20种物质的质量分数差异均有统计学意义;生茶和熟茶的色差差异明显,生茶a*值和b*值分别显著高于和低于熟茶;经相关性分析发现,生茶汤色与可溶性总糖显著正相关,熟茶汤色与茶多酚显著正相关;生茶滋味与没食子酸显著负相关,熟茶滋味与绿原酸、对羟基肉桂酸和咖啡酸显著负相关.     

汇水区土地利用方式对水库水质的影响

为探索人类活动对汇水区水质的影响,以重庆市渝北区50个水库汇水区为研究地点,应用景观生态学的原理与技术,从汇水区的角度探讨了土地利用类型的景观组成与景观格局特点对水库水质的影响.结果显示:1)建设用地比例对NH_3-N质量浓度变化的影响最大,其相关系数值最高(r=0.494,p0.01);草地面积与综合评价指数、TN之间表现出了极具有统计学意义的负相关关系(p0.01).通过多重对比发现,当建设用地比例为10%时,水库中含氮污染物质量浓度上升幅度明显增加,而当林地比例20%时,水库水质的综合评价指数降低幅度明显增加.2)水库汇水区中,建设用地斑块最大斑块指数、聚集度、连通性指数与TN,NH_3-N之间表现出极有统计学意义的正相关关系(p0.01),林地斑块间的几何平均临近距离与TP、综合评价指数之间表现出了极具有统计学意义的正相关关系(p0.01).     

利用静息态功能磁共振对腰三针治疗腰椎间盘突出症的机制研究

目的:探讨静息状态下功能性磁共振成像(fMRI)腰椎三针镇痛的变化及针刺镇痛的作用机制。方法:选取医院腰椎间盘突出症患者92例,其中男45例,女47例,随机分为传统体针组50例和腰三针组42例。传统体针组针刺大肠俞天应穴,配穴为关元俞穴并且直刺和停留,腰三针组针刺肾俞,大肠俞和委中。治疗结束后用静息核磁共振扫描,然后用SPM5软件将数据填入得到ReHo图像。结果:腰三针组和传统体针组的ReHo值(P0.05),相同脑区有双侧小脑半球等12个脑区。腰三针组ReHo值升高(P0.05)的脑区有右侧下顶叶等5个脑区,ReHo值下降(P0.03)脑区有左侧中央后回等5个脑区。结论:传统体针、腰三针通过患者疼痛的中枢镇痛调节针刺疗法,穴位和针刺两处理的差异造成了两个信息的机制和不同的镇痛效果。     

树形对龙安柚叶片生理状况及果实品质的影响

以自然圆头形、开心形和Y字形的5年生龙安柚为试材,测定了营养枝和结果枝叶片的水分、营养元素的质量分数和光合特性等生理指标及果实品质,并分析了各项生理指标与果实品质的相关性.结果表明:(1)3种树形营养枝叶片的干物质的质量分数、叶面积、水分利用效率和净光合速率均高于结果枝,且3种树形的这几项指标从大到小的顺序为:Y字形、开心形、自然圆头形.而且自然圆头形的蒸腾速率最大,为3.18 mmol/m~2·s.(2)开心形叶片的大量元素(N,P,Ca,Mg)的质量分数较其他两种树形高,且均表现为营养枝高于结果枝,其中营养枝叶片N,P,Ca,Mg的质量分数分别为2.45%,0.11%,6.54%,0.40%;Y字形和圆头形叶片微量元素(Fe,Mn,Zn,Cu,B)的质量分数高于开心形,其中Mn,Cu的质量分数为营养枝显著高于结果枝,但Fe,Zn,B的质量分数为营养枝显著低于结果枝.(3)Y字形和开心形的果实色泽、单果质量和果形指数均优于自然圆头形,其中开心形单果质量是自然圆头形的1.12倍;Y字形可溶性固形物的质量分数(10.33%)、Vc质量比(0.618 mg/g)、还原糖的质量分数(3.81%)、固酸比(16.78%)、糖酸比(13.54%)均显著高于其他树形,而可滴定酸、转化糖、蔗糖和总糖的质量分数差异不具有统计学意义.(4)营养枝、结果枝叶片的含水量、叶片干物质质量比、光合特性、营养元素的质量分数对果实品质均有影响,其中营养枝和结果枝的净光合速率与可溶性固形物的质量分数、Vc质量比、总糖的质量分数、固酸比、糖酸比均呈正相关.     

8~12 岁儿童父母教养方式与同伴接纳:心理素质的中介作用

为了探讨8~12岁儿童同伴接纳的特点及其与父母教养方式、心理素质的关系,采用简式父母教养方式问卷、小学生心理素质问卷(简化版)和同伴提名问卷对785名8~12岁儿童进行调查.结果发现:(1)父母消极教养方式、心理素质和同伴接纳存在显著的性别差异;父母积极教养方式存在显著的年级差异.(2)父母积极教养方式与心理素质和同伴接纳呈显著正相关;父母消极教养方式与心理素质和同伴接纳呈显著负相关.(3)心理素质在父母积极和消极教养方式与同伴接纳之间起显著的中介作用,中介效应占总效应的比例分别为48.45%和46.28%.研究结果表明,8~12岁儿童父母教养方式、心理素质和同伴接纳的关系密切,父母教养方式不但直接影响小学生的同伴接纳水平,还会通过心理素质间接影响小学生的同伴接纳水平.     

灭酶菠菜汁对甘薯粉条品质的影响

菠菜灭酶活后榨汁,使用菠菜汁和甘薯淀粉制作出菠菜粉条,以膨润度、煮沸损失率、断条率、色泽、感官评价等为质量评价指标,考察菠菜甘薯粉条的品质.结果显示:90℃漂烫80s后的菠菜其酶活低;与对照组相比,随着菠菜添加量增加,菠菜粉条的膨润度、弹性和粘结性降低,煮沸损失和断条率增加;剪切强度和剪切形变随着菠菜汁添加先增大后减小;L*,a*随着菠菜汁的添加而降低,b*,c*随着菠菜汁的添加而升高.综合考虑,添加25%的菠菜汁制作的菠菜粉条品质好.     

生物有机肥对黄壤烟田微生物生态特性的影响

为探明连续3年施用生物有机肥对黄壤烟田微生物生态特性的影响,本文采用田间定位试验,研究了不同培肥模式(常规处理、生物有机肥375kg/hm~2、生物有机肥750kg/hm~2、生物有机肥1 500kg/hm~2)对烟叶品质、土壤微生物数量及活性的影响.结果表明:相对于常规处理,连续3年施用生物有机肥的处理,中上等烟叶的比例都有一定程度的提高,均价、总产值和中上等烟叶的比例都有一定程度的提高,以生物有机肥750kg/hm~2处理的均价、中上等烟比例和总产值最高;相对于常规处理,生物有机肥750kg/hm~2和1 500kg/hm~2处理均明显提高了黄壤烟田土壤微生物生态特性参数(如微生物碳氮、土壤微生物熵及土壤微生物呼吸强度等),结合烤烟生产生物有机肥750kg/hm~2处理对黄壤烟田微生态改良为最佳选择.研究结果可为维持或提高黄壤烟田的生态功能提供理论依据和技术支撑.     

Temporal lobe lesions and perception of species-specific vocalizations by macaques

Japanese macaques were trained to discriminate two forms of their coo vocalization before and after unilateral and bilateral ablation of the temporal cortex. Unilateral ablation of the left superior temporal gyrus, including auditory cortex, resulted in an initial impairment in the discrimination, but similar unilateral ablation of the right superior temporal gyrus had no effect. Bilateral temporal lesions including auditory cortex completely abolished the ability of the animals to discriminate their coos. Neither unilateral nor bilateral ablation of cortex dorsal to and sparing the auditory cortex had any effect on the discrimination. The perception of species-specific vocalizations by Japanese macaques seems to be mediated by the temporal cortex, with the left hemisphere playing a predominant role.     

Reduced numbers of somatostatin receptors in the cerebral cortex in Alzheimer's disease

Somatostatin receptor concentrations were measured in patients with Alzheimer's disease and controls. In the frontal cortex (Brodmann areas 6, 9, and 10) and temporal cortex (Brodmann area 21), the concentrations of somatostatin in receptors in the patients were reduced to approximately 50 percent of control values. A 40 percent reduction was seen in the hippocampus, while no significant changes were found in the cingulate cortex, postcentral gyrus, temporal pole, and superior temporal gyrus. Scatchard analysis showed a reduction in receptor number rather than a change in affinity. Somatostatin-like immunoreactivity was significantly reduced in both the frontal and temporal cortex. Somatostatin-like immunoreactivity was linearly related to somatostatin-receptor binding in the cortices of Alzheimer's patients. These findings may reflect degeneration of postsynaptic neurons or cortical afferents in the patients' cerebral cortices. Alternatively, decreased somatostatin-like immunoreactivity in Alzheimer's disease might indicate increased release of somatostatin and down regulation of postsynaptic receptors.     

Dyslexia: cultural diversity and biological unity

The recognition of dyslexia as a neurodevelopmental disorder has been hampered by the belief that it is not a specific diagnostic entity because it has variable and culture-specific manifestations. In line with this belief, we found that Italian dyslexics, using a shallow orthography which facilitates reading, performed better on reading tasks than did English and French dyslexics. However, all dyslexics were equally impaired relative to their controls on reading and phonological tasks. Positron emission tomography scans during explicit and implicit reading showed the same reduced activity in a region of the left hemisphere in dyslexics from all three countries, with the maximum peak in the middle temporal gyrus and additional peaks in the inferior and superior temporal gyri and middle occipital gyrus. We conclude that there is a universal neurocognitive basis for dyslexia and that differences in reading performance among dyslexics of different countries are due to different orthographies.     

Lateralized cognitive processes and lateralized task control in the human brain

The principles underlying human hemispheric specialization are poorly understood. We used functional magnetic resonance imaging of letter and visuospatial decision tasks with identical word stimuli to address two unresolved problems. First, hemispheric specialization depended on the nature of the task rather than on the nature of the stimulus. Second, analysis of frontal candidate regions for cognitive control showed increased coupling between left anterior cingulate cortex (ACC) and left inferior frontal gyrus during letter decisions, whereas right ACC showed enhanced coupling with right parietal areas during visuospatial decisions. Cognitive control is thus localized in the same hemisphere as task execution.     

Prefrontal regions orchestrate suppression of emotional memories via a two-phase process

Whether memories can be suppressed has been a controversial issue in psychology and cognitive neuroscience for decades. We found evidence that emotional memories are suppressed via two time-differentiated neural mechanisms: (i) an initial suppression by the right inferior frontal gyrus over regions supporting sensory components of the memory representation (visual cortex, thalamus), followed by (ii) right medial frontal gyrus control over regions supporting multimodal and emotional components of the memory representation (hippocampus, amygdala), both of which are influenced by fronto-polar regions. These results indicate that memory suppression does occur and, at least in nonpsychiatric populations, is under the control of prefrontal regions.     

Direct evidence for a parietal-frontal pathway subserving spatial awareness in humans

Intraoperative electrical stimulation, which temporarily inactivates restricted regions during brain surgery, can map cognitive functions in humans with spatiotemporal resolution unmatched by other methods. Using this technique, we found that stimulation of the right inferior parietal lobule or the caudal superior temporal gyrus, but not of its rostral portion, determined rightward deviations on line bisection. However, the strongest shifts occurred with subcortical stimulation. Fiber tracking identified the stimulated site as a section of the superior occipitofrontal fasciculus, a poorly known parietal-frontal pathway. These findings suggest that parietal-frontal communication is necessary for the symmetrical processing of the visual scene.     

Human brain: left-right asymmetries in temporal speech region

We have found marked anatomical asymmetries between tile upper surfaces of the human right and left temporal lobes. The planum temporale (the area behind Hesch's gyrus) is larger on the left in 65 percent of brains; on the right it is larger in only 11 percent. The left planum is on the average one-third longer than the planum. This area makes up part of the temporal speech cortex, whose importance is well established on the basis of both anatomical findings in aphasic patients ans cortical stimulation at operation.     

Cortical mechanisms of human imitation

How does imitation occur? How can the motor plans necessary for imitating an action derive from the observation of that action? Imitation may be based on a mechanism directly matching the observed action onto an internal motor representation of that action ("direct matching hypothesis"). To test this hypothesis, normal human participants were asked to observe and imitate a finger movement and to perform the same movement after spatial or symbolic cues. Brain activity was measured with functional magnetic resonance imaging. If the direct matching hypothesis is correct, there should be areas that become active during finger movement, regardless of how it is evoked, and their activation should increase when the same movement is elicited by the observation of an identical movement made by another individual. Two areas with these properties were found in the left inferior frontal cortex (opercular region) and the rostral-most region of the right superior parietal lobule.     

基于体素的形态学方法对阿兹海默症患者脑灰质结构的检测

目的 利用颅脑磁共振图像研究阿尔茨海默病(AD)患者脑灰质体积的改变.方法 利用DARTEL方法对11例AD患者(AD组)和11例健康对照者(HC组)的三维颅脑磁共振图像进行预处理,并对两组数据的全脑灰质进行基于体素的统计学分析.结果 与HC组比较,AD组的双侧海马、海马旁回、杏仁核、颞上回、颞中回、尾状核、豆状核、岛叶、小脑脚等结构灰质体积明显萎缩,差异有统计学意义(FDR校正,P＜0.05,体素≥50).结论 基于体素的形态学测量能够显示AD患者的脑灰质结构萎缩情况,有助于AD的早期诊断和病情监测.