非空间线索相容性事件相关电位研究

目的:通过考察前置线索与刺激在颜色与形状2个维度上的重合关系对目标刺激的影响,探讨刺激与反应在不相容程度条件下,线索与刺激的相容性对反应产生影响的神经基础。方法:实验于2003-11在北京师范大学心理学院实验室完成。对象为北京师范大学本科生12人。均为右利手,视力或矫正视力正常,颜色知觉正常。实验在隔音的暗室中进行,刺激是红、绿、蓝3种颜色的平面图形和立体图形,自变量是线索和目标的4个对应关系。每次实验开始前,屏幕中央呈现注视点1000ms,间隔300ms之后呈现线索1000ms,再间隔300ms呈现目标,要求被试按反应盒上的1,2,4键对目标做出反应。实验216次,按随机顺序呈现。记录从刺激呈现前200ms到呈现后1000ms前部的15个电极和后部的8个电极,并按照4个时间窗口(100～160ms,前部N1,后部P1;170～230ms,N2;280～400ms,前部P3;320～420ms,后部P3)的峰值和潜伏期进行统计分析。结果:12人均获检测,全部进入结果分析。①额叶与顶叶N1和P3的峰值分析:在刺激呈现以后100～160ms,额叶和顶叶的N1波的不同条件的主效应显著,电极位置的主效应显著。电极与条件的交互作用不显著。在刺激呈现之后280～400ms,P3波的条件主效应也接近显著,电极位置的主效应显著。②枕叶P1、N2、P3的峰值分析:在刺激呈现之后100～160ms,枕叶P1波条件的主效应不显著,而电极位置的主效应显著。在170～230ms,N2波主效应接近显著,线索与目标形状相同颜色不同时诱发了更负的波。电极位置的主效应也是接近显著的。但P1和N2的条件和电极交互作用均不显著。P3(320～420ms)波的条件和电极位置的交互作用显著。简单效应分析结果显示,除在P4和P12个电极上,4种条件的差异接近显著,在其他6个电极上,4种条件的差异都非常显著。线索和目标在2个维度完全重合条件下诱发了更正的波,颜色相同形状不同时峰值居中,而形状和颜色都不同、形状相同颜色不同时峰值最小。③潜伏期的分析:额叶和顶叶N1波的条件主效应显著。P3波的条件主效应也显著,与额叶和顶叶相比,枕叶的3种事件相关电位成分P1、N2和P3的潜伏期的主效应均不显著。额叶和顶叶的N1波在早期刺激-反应相容性任务加工中对形状较为敏感,P3波对颜色较为敏感。结论:额叶和顶叶对刺激-反应相容性任务加工的早期起着主要作用,枕叶在刺激-反应相容性任务加工后期选择反映阶段的作用更为明显。额叶和顶叶的N1波在早期刺激-反应相容性任务加工中表现出对形状判断较为敏感,P3波对颜色的状判断较为敏感。刺激-反应相容性效应可能是视觉-动作转换或是对不同反应的选择造成的,注意在刺激-反应相容性任务中对形状加工起着十分重要的作用。     

生长激素型垂体腺瘤伽玛刀治疗的疗效分析

目的 评价leksell伽玛(γ)刀治疗生长激素型垂体腺瘤的疗效.方法 对我院自2005年1月至2008年3月应用伽玛刀治疗41例生长激素型垂体腺瘤患者进行回顾性分析,肿瘤直径4～38.6mm,平均15.2mm.采用1.5T磁共振定位,Ganuna-Plan计划系统规划,等剂量曲线16%～60%,治疗周边剂量9.95～35 Gy,中心剂量31.25～70 Gy.结果 33例获随访,30例(90.9%)患者临床症状改善,16例(48.4%)患者的血清生长激素(GH)值降到正常水平,12例(36.3%)患者GH值下降,4例(12.1%)患者GH值无变化.24例(72.7%)患者肿瘤缩小,9例(27.2%)患者肿瘤无改变.结论 γ刀治疗在控制生长激素型垂体腺瘤生长和改善内分泌症状是安全有效的,是GH微腺瘤首选治疗方法;对肿瘤术后残存或复发,尤其是侵袭海绵窦的患者,γ刀是最好的补充治疗.     

Focal cerebral ischemia induces Alzheimer’s disease-like pathological change in rats

The changes in the tau protein phosphorylation and expression of bcl-2,and bax in rat parietal cortex neurons after focal cerebral ischemia-reperfusion(I/R)were explored,and the relationship between the tau protein phosphorylation and the expression of bax or apoptosis was clarified in order to elucidate the relationship between cerebral infarction and Alzheimer's disease.The rat focal cerebral I/R model was induced by occlusion of the right middle cerebral artery using the intraluminal suture method.The le...     

钛表面梯度生物活性涂层材料在颅骨修补中的生物性能

BACKGROUND: Titanium mesh has good clinical effect in repairing skull defects, but due to the lack of bone induction ability, the titanium mesh has a poor integration with the bone tissue. OBJECTIVE: To observe the biological properties of the gradient bioactive coating materials on the titanium surface in the skull repair. METHODS: Osteoblasts were co-cultured with the titanium mesh with or without gradient bioactive coatings for 14 days, and then cell proliferation was detected using MTT method. Seventy-one patients with skull defects were enrolled, including 43 males and 28 females, aged 15-60 years, and were subjected to skull repair using the titanium mesh with (observation group, n=3) or without (control group, n=38) gradient bioactive coatings. During the postoperative follow-up of 12 months, the repairing effects and adverse reactions were observed in the two groups. RESULTS AND CONCLUSION: (1) In vitro cell culture: the cell proliferative ability was increased significantly in the observation group as compared with the control group at 8, 10, 12 and 14 days after cell culture. (2) In vivo repair: the hospital stay and wound healing time in the observation group were significantly lower than those in the control group (P < 0.05), and at the final follow-up, the postoperative recovery effect was significantly higher in the observation group than the control group (P < 0.05). The titanium meshes were fixed firmly in the two groups, with no floating, infection and exposure. These results show that the titanium mesh with gradient bioactive coating has good biocompatibility and osteoinduction capacity.