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51.
To enhance medical cooperation between the hospitals and clinics around Osaka local area, the healthcare network system, named Osaka Community Healthcare Information System (OCHIS), was established with support of a supplementary budget from the Japanese government in fiscal year 2002. Although the system has been based on healthcare public key infrastructure (PKI), there remain security issues to be solved technically and operationally. An experimental study was conducted to elucidate the central and the local function in terms of a registration authority and a time stamp authority in contract with the Japanese Medical Information Systems Organization (MEDIS) in 2003. This paper describes the experimental design and the results of the study concerning message security.  相似文献   
52.
In vitro experiments were performed on brainstem – spinal cord preparations from mouse neonates to compare the noradrenergic regulations of the respiratory network in the control C3H/HeJ strain and the transgenic Tg8 strain which has been created from the C3H/HeJ strain by deletion of the gene encoding monoamine oxidase A (MAOA), the main enzyme for serotonin degradation. In both control and MAOA-deficient strains, we show: (i) that the pontine A5 area exerts a potent inhibitory modulation on the respiratory rhythm generator; (ii) that noradrenaline application induces a tonic phrenic activity; and (iii) that noradrenaline increases the respiratory rhythm. The latter effect is however delayed and weak in the Tg8 strain. Therefore, MAOA-deficiency has only slightly altered the noradrenergic regulations of the respiratory network.  相似文献   
53.
54.
用高价人抗HBs在人体内诱导产生抗HBs   总被引:2,自引:0,他引:2  
胡其乐  王泓 《免疫学杂志》1990,6(3):179-182
本文探讨用外源性人抗HBs在人体通过免疫网络诱导产生自身的抗HBs的可能性。志愿者经多次注射人高价抗HBs(Ab_1)后,体内产生了Ab_2,进而产生出特异性与Ab_1相同的Ab_3;当Ab_3水平升高时,Ab_2水平下降。此结果证实了人体内独特型网络的存在及其活跃的调节功能,表明用于被动免疫的人抗HBs在人体也能通过激活独特型网络产生主动免疫保护作用。此外,本文的结果还提示,注射人抗HBs后,人体内产生的Ab_2可模拟HBsAg,使常规的HBsAg检查出现假阳性结果。  相似文献   
55.
大学生个体印象管理对其社会网络质量的影响   总被引:1,自引:0,他引:1  
目的:研究个体印象管理对其社会网络质量的影响。方法:选用社会网络调查法、大学生印象管理量表,对46名大学生进行调查。结果:印象管理建构的提高不利于朋友网和沟通网的强联系人数量的增加(β分别为-1.04和-1.33,P分别小于0.05和0.01;F值分别为4.19和6.45,P分别小于0.05和0.01),而印象管理动机对强联系人的数量并没有影响,并且印象管理动机和印象管理结构都不影响个体为中心网络的紧密性。结论:只有个体印象管理的建构部分不利于其社会网络中的强联系人数量的增加。其他部分对社会网络无明显影响。  相似文献   
56.
D. Plenz  A. Aertsen 《Neuroscience》1996,70(4):893-924
Neural dynamics in organotypic cortex-striatum co-cultures grown for three to six weeks under conditions of dopamine deficiency are described. Single neuron activities were recorded intra- and extracellularly, and spatiotemporal spreading of population activity was mapped using voltage-sensitive dyes. The temporal properties of spike firing were characterized by interspike interval histograms, autocorrelation and crosscorrelation.

Cortical pyramidal neurons (n = 40) showed irregular firing with a weak tendency to burst or to oscillate. Crosscorrelations revealed strong near-coincident firing and synaptic interactions. Disinhibition was a notable feature in a strongly firing cortical interneuron. Cortical activity spread in the co-culture, thus inducing an overall, homogeneous depolarization in the striatal part. Striatal cells were divided into principal cells and type I and II secondary cells. Principal cells (n = 40) were similar to those reported previously in vivo. Spiking activity ranged from irregular spiking at very low rates to episodic bursting, with an average burst duration of 1 s. Interspike intervals were single-peaked. Intracellular recordings revealed characteristic, long-lasting subthreshold depolarizations (“enabled state”) that were shortened by local muscarinic receptor blockade. During prolonged time periods in the “enabled state”, locally applied bicuculline induced strong firing in most principal neurons. Striatal secondary type I neurons (n = 25) showed high spiking rates, single- and double-peaked interval histograms and low-threshold, short-lasting stereotyped bursting activity and occasional rhythmic bursting. The firing of these neurons was increased by bicuculline. Crosscorrelations showed synchronization of these cells with principal cell activity. Secondary type II neurons (n = 15) revealed tonic, irregular firing patterns similar to cortical neurons, except with occasional firing in doublet spikes.

We conclude that under conditions of dopamine deficiency in corticostriatal co-cultures (i) the cortex induces the “enabled” state and typical bursting mode in striatal principal neurons; (ii) principal neurons are strongly inhibited during the “enabled” state; (iii) muscarinic activity, presumably from tonically active striatal cholinergic interneurons, stabilizes the “enabled” state; (iv) striatal GABAergic interneurons receive synaptic inhibition and take part in synchronized activity among striatal principal cells. Our results favor the view of the striatum as a lateral inhibition network.  相似文献   

57.
目的:观察高血压急诊快速降血压对大脑功能的影响情况。方法:监测56例病人含服 降压药前后的脑电活动和血压情况,并对所获资料进行分析。结果:2 h内收缩压(SBP)下降>5.33 kPa (40 mmHg)或舒张压(DBP)下降>4.00 kPa(30 mmHg)时,脑电图异常程度增加,θ及δ频段功率值明 显升高(P<0.01)。结论:降压急骤,可能会造成大脑功能损害  相似文献   
58.
The paper presents an adaptive noise canceller (ANC) filter using an artificial neural network for real-time removal of electro-oculogram (EOG) interference from electro-encephalogram (EEG) signals. Conventional ANC filters are based on linear models of interference. Such linear models provide poorer prediction for biomedical signals. In this work, a recurrent neural network was employed for modelling the interference signals. The eye movement and eye blink artifacts were recorded by the placing of an electrode on the forehead above the left eye and an electrode on the left temple. The reference signal was then generated by the data collected from the forehead electrode being added to data recorded from the temple electrode. The reference signal was also contaminated by the EEG. To reduce the EEG interference, the reference signal was first low-pass filtered by a moving averaged filter and then applied to the ANC. Matlab Simulink was used for real-time data acquisition, filtering and ocular artifact suppression. Simulation results show the validity and effectiveness of the technique with different signal-to-noise ratios (SNRs) of the primary signal. On average, a significant improvement in SNR up to 27 dB was achieved with the recurrent neural network. The results from real data demonstrate that the proposed scheme removes ocular artifacts from contaminated EEG signals and is suitable for real-time and short-time EEG recordings.  相似文献   
59.
在这篇论文中,我们提出了用于选择视觉的数据和智能控制的动态网络系统的神经实现过程。模型由数个相互作用的子系统构成,用于不同的处理。所有的神经子系统与信息和控制流程的倒序和顺序紧密相关。  相似文献   
60.
The aim of this functional magnetic resonance imaging study was to investigate differences in visuomotor control with increasing task complexity. Twelve right-handed volunteers were asked to perform their signature under different degrees of visual control: internally generated movement with closed eyes, signing with open eyes, tracking the line of the projected signature forwards, and tracking the line of the projected signature backwards. There was a gradual onset and disappearance of activation within a distributed network. Parietal, lateral and medial frontal brain areas were activated during all conditions, confirming the involvement of a parieto-frontal system. The weight of activation shifted with increasing task complexity. Internally generated movements activated predominantly the inferior parietal lobule and the ventral premotor cortex, as well as the rostral cingulate area, pre-supplementary motor area (pre-SMA) and SMA proper. Opening the eyes reduced SMA and cingulate activation and activated increasingly the occipito-parietal areas with higher task complexity. Visually guided movements produced an activation predominantly in the superior parietal lobule and dorsal premotor cortex. This study bridges human activation studies with the results of neurophysiological studies with monkeys. It confirms a gradual transition of visuomotor control with increasing task complexity within a distributed parieto-frontal network.  相似文献   
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