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M. Doyle B. L. W. Chapman G. Blackwell E. G. Walsh G. M. Pohost 《Magnetic resonance in medicine》1994,31(5):546-550
We introduce an image processing method which reduces white noise and random artifacts in sets of high resolution, time resolved images. At each pixel, the processing consists of: (1) the isolation of a time intensity curve (TIC), (2) Fourier transformation of each TIC, (3) application of a threshold to remove low intensity coefficients, (4) inverse transformation to generate noise reduced TICS which are recombined to form images with improved signal-to-noise ratio (SNR). Noise filtering by Fourier thresholding is demonstrated on a set of cardiac images, resulting in a reduction of the noise energy by approximately 90%. 相似文献
54.
This paper examines the manner in which Vietnamese refugees acces the healthcare system in Victoria, British Columbia. A major theme of this study was the identification of barriers to health care access and provision as perceived by refugees and health care providers, as well as areas of overlap between the two sets of perceptions. The study was based on interview protocols developed with key informants followed by structured samples of 20 Vietnamese and 20 health care workers. The major issue identified by both groups was problematic interpretation of patient symptoms and health care provider recommendations. Lack of health care worker understanding of traditional remedies for common ailments was also identified as a barrier to health care access and utilization. The special problems of unemployment, depression, surviving torture and getting assistance are all made more difficult for refugees living in a smaller urban centre which lacks sufficiently large ethnic populations to assist in service provision. A number of suggestions are made which might ameliorate the difficulties of refugees living in smaller communities. These include municipally based client advocates and special translation training for existing hospital staff. 相似文献
55.
金星明 《中国妇幼健康研究》2003,14(5):270-271
现代生活中 ,儿童的语言和识字受家庭认知环境的影响。近年来无论从流行病学的研究 ,还是干预或神经生物的研究 ,均证实儿童早期经验是日后语言和识字能力发展的基础。在早期经验中 ,最关键的是父母与孩子之间的语言交流。通过这样的交流 ,促进儿童早期的语言发育 ,也促进儿童学龄期的阅读理解。儿童保健医生处于独特的位置 ,即在常规保健中指导父母根据不同年龄儿童的发育水平 ,应用有关的技能技巧 ,促进儿童的语言和识字。 相似文献
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Anthony M. Norcia Russell D. Hamer Arthur Jampolsky Deborah Orel-Bixler 《Vision research》1995,35(23-24)
Monocular oscillatory-motion visual evoked potentials (VEPs) were measured in prospective and retrospective groups of infantile esotropia patients who had been aligned surgically at different ages. A nasalward-temporal response bias that is present prior to surgery was reduced below pre-surgery levels in the prospective group. Patients in the retrospective group who had been aligned before 2 yr of age showed lower levels of response asymmetry than those who were aligned after age 2. The data imply that binocular motion processing mechanisms in infantile esotropia patients are capable of some degree of recovery, and that this plasticity is restricted to a critical period of visual development. 相似文献
57.
Vadim S. Rotenberg 《Neuroscience and biobehavioral reviews》1994,18(4):487-495
The present paper proposes a new psychophysiological approach to the genesis of positive and negative schizophrenic symptoms. According to this approach, the initial factor in schizophrenic disorders is a functional insufficiency of the right hemisphere which can be determined by early emotional experience in combination with subtle brain damage. This functional insufficiency causes (a) the inability to grasp and select information before its realization; and (b) the inability to produce a polysemantic context which is crucial for creativity, psychological defense, and the restoration of search activity, all of which determine psychophysiological adaptation to the environment. Right hemisphere insufficiency causes left hemisphere hyperactivity as an ineffective attempt to compensate for this functional deficiency. As a result, normal search activity is replaced by artificial search activity which is represented by “positive” symptoms, and which uses the predisposition of the left hemisphere's catecholamine system for its increased activity. The suggestion is made that cognitive impairment in schizophrenia (the inability to use appropriate previous information in relation to current perceptual input) is related to the competition between information processing which requires left hemisphere activity, and the formation of positive symptoms, also based on left hemisphere activity. 相似文献
58.
目的 采用脑磁图(magnetoencephalograph,MEG)的等价电流偶极子定位法(Equivalent current dipole,ECD)和合成孔径磁场定位法(SAMSynthetic、Aperture Magnetometry,SAM)定位母语为汉语的健康自愿者的语占中枢,探讨汉字的语言处理过程。方法 对10例母语为汉语的健康受试者给予默读真词、假词的语言任务刺激,记录刺激后产生的诱发磁场,将采集的数据与MRI叠加获得磁源性影像(MSI Magnetic source imaging)语占功能区定位川同样的方法对4例胶质瘤患者进行术前语言功能区定位,术中皮层电刺激所定位语言功能区,明确是否产生言语障碍。结果 所有受试者真词、假词均在双侧大脑半球诱发出明显的晚期磁反应波,左侧大脑半球磁反应波分化较右侧大脑半球好,Broea区俯于额下回后部,Wernicke区位于颞中同、颢上回、缘上回,Wernieke区先于Broca区出现。胶质瘤患者术巾电刺激所定位的Broca区、Wernicke区均产生言语障碍:结论母语为汉语的正常人的Broca区Wernieke区与经典的语言中枢糕本相符,MEG定位语言中枢的技术是可行的。 相似文献
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The Vaccine Safety Datalink (VSD) is a collaboration between the CDC and eight large HMOs to investigate adverse events following immunization through analyses of clinical data. We modified an existing system, called MediClass, that uses natural language processing to identify clinical events recorded in electronic medical records (EMRs). We customized MediClass so it could detect possible vaccine adverse events (VAEs) generally, and gastrointestinal-related VAEs in particular, in the text clinical notes of encounters recorded in the EMR of a large HMO. Compared to methods that use diagnosis and utilization codes assigned to encounters by clinicians and administrators, the MediClass system can both find more adverse events and improve the positive predictive value for detecting possible VAEs. 相似文献