醒脑静注射液对脑缺血再灌注小鼠记忆功能的保护作用

目的：观察醒脑静（XNJI）对脑缺血再灌注后小鼠记忆功能的保护作用。方法：采用暂时性阻断两侧颈总动脉的方法制备小鼠脑缺血再灌注损伤的模型。测试其被动回避能力，脑内抗氧化酶活性及小鼠断头喘气时间，结果：XNJI可延长脑缺血再灌注小鼠的避暗潜伏期，减少错误次数，并提高谷胱甘肽过氧化物酶（GSH-Px)的活性。延长小鼠断头喘气时间。结论：XNJI可明显减轻脑缺血再灌注导致的小鼠学习记忆功能障碍状态。其主要机制可能与抗氧化作用有关。     

普洛托品对正常大鼠学习能力及海马、大脑皮层乙酰胆碱酯酶活性的影响

目的：观察普洛托品（protopine,Pro)对正常大鼠学习能力及海马、大脑皮层乙酰胆碱酯酶活性的影响。方法：大鼠每天Pro 0.5mg/kg灌胃，28d后三等分Y迷宫测定大鼠学习成绩，并测定海马及大脑皮层乙酰胆碱酯酶活性。结果：Pro组大鼠达到学会标准所需的训练次数明显减少，与对照组比较差异有极显著性（P＜0．01），Pro组大鼠海马及大脑皮层乙酰胆碱酯酶活性亦明显降低，与对照组比较差异有显著性（P＜0．01，P＜0．05），结论：Pro可提高正常大鼠学习能力，并降低海马及大脑皮层乙酰胆碱酯酶活性。     

Serial order short-term memory capacities and specific language impairment: No evidence for a causal association

This study re-explored the nature of verbal short-term memory (STM) deficits in children with specific language impairment (SLI), by distinguishing item and serial order STM processes. Recent studies have shown serial order STM capacity to be a critical determinant of language development, relative to item STM. In Experiment 1, 12 children with SLI, 12 age-matched children and 12 language-matched children were administered serial order recognition and reconstruction tasks. Experiment 2 assessed implicit serial learning abilities via a Hebb learning task. The SLI group showed impaired performance for the serial order reconstruction and recognition tasks, relative to language-matched and/or age-matched control groups. However, normal serial position effects were observed in all SLI children in the serial order reconstruction task, suggesting normal coding of serial position information. Similarly, performance on the Hebb serial learning task was at chronological age appropriate levels. Experiment 3 showed that the group differences observed for the serial order STM tasks in Experiment 1 disappeared when the SLI group was compared to a mental age-matched control group. Experiment 4 showed similar performance levels in the SLI group and the mental age-matched control group for a nonword recognition task assessing item STM capacities. This study shows that children with SLI have no specific impairments for serial order and item STM components but that poorer general cognitive efficiency is related to functional limitations in verbal STM tasks. The data are in line with limited information processing accounts of SLI.     

Generalization of Frequency Discrimination Learning Across Frequencies and Ears: Implications for Underlying Neural Mechanisms in Humans

Frequency discrimination thresholds (FDTs) at 750, 1500, 3000, and 6000 Hz were measured in 32 normal-hearing listeners before and after each listener practiced the task for 12 h at one of the above frequencies using a single ear. Marked improvements in thresholds taking place over several hours were observed during the frequency- and ear-specific training period. Comparisons between pre- and posttraining thresholds showed large improvements at the trained frequency, but also at other frequencies. The improvements were initially slightly—but significantly—larger at the trained frequency than at untrained frequencies. However, this trained-frequency advantage disappeared rapidly during the course of the two-hour multifrequency posttraining session, suggesting rapid relearning or learning generalization across frequencies. In contrast, no significant ear specificity was found, not even at early stages of the posttraining session. These findings add to earlier results suggesting that, in humans, frequency discrimination learning is only weakly frequency-specific, and they reveal that a complete generalization across frequencies can occur rapidly with little retraining at the initially untrained frequencies. Implications regarding underlying mechanisms are discussed.     

学习优良与不良中学生记忆特点的比较研究

目的探讨学习优良和不良中学生的记忆特点,为学习不良学生的教育提供科学依据。方法采用北京大学PES心理实验系统中的内隐记忆实验对学习优良和学习不良中学生各16名进行测试。结果学习优良和学习不良中学生的启动效应值均值分别为0.29和0.34,差异无统计学意义(P>0.05);学习优良与不良中学生的再认保持量均值分别为30.00和25.25,差异有统计学意义(P<0.01)。结论学习优良和不良中学生的内隐记忆无差异,学习优良中学生外显记忆优于学习不良中学生。提高学习不良学生的学习成绩应从外显记忆着手,同时兼顾内隐记忆的作用。     

NIKKISO DBB-27型血液透析机液路系统工作原理及故障报警分析

分析了NIKKISO DBB-27型血液透析机液路系统的系统结构及各组成部分的工作原理,并对相关故障报警的诊断和排除进行了详细论述,为及时、准确地诊断和排除血液透析机的故障提供了理论基础。     

一种西门子新型X线机的综合性能与安装

本文叙述西门子型号为Polydoros 80/100的新型X线主机,该主机采用微电脑控制技术、光纤维传输技术及中频技术,X射线剂量精度高,影像质量优良,故障率低,是一种技术较为成熟的X线主机,也是当今西门子公司产品的主流机种。该机的安装调试具有一定难度,本文同时针对这一问题进行讨论,并总结归纳出一套安装调试全过程。     

神经节苷酯对老年性学习记忆减退鼠空间学习记忆能力的影响

目的研究神经节苷酯对老年性学习记忆减退鼠空间学习记忆的影响。方法用Ｍｏｒｉｓ水迷宫筛选老年性学习记忆减退昆明小鼠，腹腔注射神经节苷酯１４天，然后测试小鼠定位航行和空间探索能力。结果与老年学习记忆减退鼠对照组比较，治疗组平均逃避潜伏期缩短，原平台游泳距离和穿环数次却增大，但均未达到老年学习记忆正常组和青年组水平。结论提示神经节苷酯可改善老年性学习记忆减退鼠空间学习记忆能力。