An effect of triazolam on visual attention and information processing

This study explored whether benzodiazepines selectively affect aspects of attention and/or visual information processing, as they do memory. A cued visual-search paradigm was employed, using normal volunteers and a single dose of triazolam. This paradigm provided for a detailed examination of two aspects of visual attention and information processing: 1) controlled versus automatic attention allocation (via central and peripheral cues), and 2) the extent to which processing an item in a non-cued location affects performance (via cue-validity). Triazolam, compared to placebo, significantly increased response time, and Drug Condition interacted with Cue-Validity but not Cue-Type. Based on these data, we argue that triazolam doesnot affect attention allocation butdoes affect attentional disengagement and/or attention switching mechanisms.     

喉部CT仿真内窥镜成像技术的探讨

目的：探讨喉部CT仿真内窥镜(CT virtual endoscopy，CTVE)的成像质量及其影响因素。方法：对84例喉部螺旋CT扫描者行CTVE成像，根据喉腔内部结构、病灶、黏膜皱襞的显示情况和有无伪影将CTVE图像分为3级，分别比较CTVE技术在不同的扫描层厚、重建层厚及阈值的情况下图像质量的优劣。结果：CT原始扫描层厚为2mm、3mm分别与5mm、8mm的CTVE图像质量相比较，有显著性差异(P＜0．05)；重建层厚为2mm、3mm与5mm相比较，均有显著性差异(P＜0．05)；阈值为 -800— -600HU与阈值为-300HU相比较，有显著性差异(P＜0．05)。结论：不同的CT原始扫描层厚、重建层厚及阈值对CTVE图像的质量影响有明显差异。选用合适的原始扫描参数及重建参数，可以提高CTVE图像的质量，对喉部疾病的诊断很有帮助。     

中医舌象计算机识别研究的现状分析

从静态舌图像计算机识别研究的关键环节出发,对当前的研究现状进行了分析.认为在舌图像的采集方面有必要引入正交设计、图像质量评价等方法以筛选出高标准、统一、实用的图像采集条件;图像分割研究可以考虑从多角度入手,综合使用多种分割方法,取长补短,以提高分割效果;同时采用Delphi评价法、多中心的网上专家判别等手段,大样本集中专家经验,综合各家的辨舌经验,建立科学规范的舌象诊断标准;当前舌象识别研究的热点主要集中在舌的颜色领域,研究的方向有待向颜色以外的其他方面拓展,并最终由定性向定量转化,而实现舌诊内容的综合判别将是今后努力的方向.     

云纹技术在断裂分析中的应用

改进了传统的云纹数据处理方法,提出用曲面拟合方法处理云纹数据,提高了计算机处理云纹数据的效率与质量。又提出用云纹法测量J积分的技术,可望解决实际工程构件的J积分测量问题。     

中医美容多媒体查询系统的数据库设计

将中医美容知识的查询系统与多媒体技术结合，使用ＦｏｘＰｒｏｆｏｒＷｉｎｄｏｗｓ完成查询系统的主要设计思想。设计思想包括数据库设计、查询设计、图像处理和菜单设计４个方面。     

Pulsed magnetization transfer spin-echo MR imaging

Cross relaxation between macromolecular protons and water protons is known to be important in biologic tissue. In magnetic resonance (MR) imaging sequences, selective saturation of the characteristically short T2 macromolecular proton pool can produce contrast called magnetization transfer contrast, based on the cross-relaxation process. Selective saturation can be achieved with continuous wave irradiation several kilohertz off resonance or short, intense 0° pulses on resonance. The authors analyze 0° binomial pulses for T2 selective saturation, present design guidelines, and demonstrate the use of these pulses in spin-echo imaging sequences in healthy volunteers and patients. Using the phenomenologic Bloch equations modified for two-site exchange, the authors derive the analytic expressions for water proton relaxation under periodic pulsed saturation of the macromolecular protons. This relaxation is shown to be monoexpo-nential, with a rate constant dependent on the saturation pulse repetition rate and the individual and cross-relaxation rates.     

The Role of Horizontal Connections in Generating Long Receptive Fields in the Cat Visual Cortex

The cells in the primary visual cortex possess numerous functional properties that are more complex and varied than those seen in the cortical input. These properties result from the network of intrinsic cortical connections running across the cortical layers and between cortical columns. In the current study we relate the long receptive fields that are characteristic of layer 6 cells to the input that these cells receive from layer 5. The axons of layer 5 pyramidal cells project over long distances within layer 6, enabling layer 6 cells to collect input from regions of cortex representing large parts of the visual field. When layer 5 was locally inactivated by injection of the inhibitory transmitter GABA, layer 6 cells lost sensitivity over the portion of their receptive fields corresponding to the inactivated region of layer 5. This suggests that the extensive convergence in the projection from layer 5 to layer 6 is responsible for generating the long receptive fields characteristic of the layer 6 cells.     

The effects of clonidine and yohimbine on human information processing

The effects of clonidine and yohimbine on human information processing were tested in six normal volunteers ages 18–30 years. Subjects were tested in a pre-post design with sessions conducted at weekly intervals. Three drug conditions were: Placebo (lactose), 0.2 mg clonidine, and 30 mg yohimbine. Two choice reaction time (RT) tasks were used. One was a stimulus evaluation-response selection task (SERS) that has been shown to be sensitive tod-amphetamine, methylphenidate and scopolamine. The other task was to assess stimulus pre-processing and used spatial frequency as a discriminative stimulus. The principle finding was that clonidine slowed RT; this effect was significant for both tasks. In contrast, yohimbine tended to speed RT, but the effects were significant only for the spatial frequency task on some analyses while not for others. RTs to high spatial frequency stimuli were speeded more than for low spatial frequency. The effects of these two NE drugs were compared with findings withd-amphetamine and scopolamine and interpreted within the framework of a serial information processing model proposed by Callaway (1983). Specifically, it is suggested that yohimbine and clonidine affect an early pre-processing stage.     

基于Client／Server结构的医院图像处理系统

作者介绍了一种医院图像处理系统，可将医院的各种设备所产生的医疗图象资料，动用先进的可读写光盘为存储介质有效地进行存储，再通过通信网络及时地传送到医院的各个部门，辅助医生进行临床诊断及科研，提高有关科室及整个医院的工作效率及经济效益。