The relationship between the long-lasting enhancement of synaptic transmission produced by a phorbol ester and the release of endogenous excitatory amino acids has been investigated in the CA1 hippocampal region of the anaesthetized rat. Using the push-pull technique, the concentration of glutamate and aspartate was assayed in the perfusate by high-pressure liquid chromatography. Application of...

Many thresholding-based image enhancement techniques have been developed and used for document analysis, where the simplicity and efficiency of thresholding makes it ideal to use for classifying layers within documents. However, the efficiency of these enhancement techniques can be impaired by the variation of grey levels in different documents, thus causing over-thresholding or under-threshold...

We discuss several lines of evidence refuting the hypothesis that procedural or declarative memories are processed/consolidated in sleep. One of the strongest arguments against a role for sleep in declarative memory involves the demonstration that the marked suppression or elimination of REM sleep in subjects on antidepressant drugs or with brainstem lesions produces no detrimental effects on c...

BACKGROUND AND PURPOSE Contrast enhancement of intracranial atherosclerotic plaques has recently been investigated using high field and high resolution MR imaging as a risk factor in the development of ischemic stroke. We studied the reliability of conventional MR imaging at 1.5T in evaluating intraplaque enhancement and its relationship with acute cerebrovascular ischemic presentations in pati...

objectives: this study aimed to compare the diagnostic accuracy of inverted and unprocessed digitized periapical radiographs for detection of peri-implant defects. materials and methods: a total of 30 osteotomy sites were prepared in three groups of control, study group 1 with 0.425 mm defects and study group 2 with 0.725 mm defects using the sic and astra tech drill systems with 4.25mm and 4.8...

The aim of this study was to analyze the correlation between the quantitative parameters of contrast-enhancement ultrasound for primary hepatocellular carcinoma (HCC) and biological manifestations of tumor (Ki-67), and to explore the related risk factors of primary hepatocellular carcinoma, so as to provide the theoretical basis for the further study on contrast-enhancement ultrasound manifesta...

High-repetition rate laser-induced damage of Ta 2 O 5 :SiO coatings was investigated at 355 nm wavelength and a repetition 30 kHz. Laser-induced thresholds with different mixture ratios were measured. The relationships between threshold the material band gap defect absorption analyzed. decreased increase in number laser pulses owing to enhancement absorption. Enhancement is attributed density m...

Synaptic modulation and long-term synaptic changes are thought to be the cellular correlates for learning and memory (Madison et al., 1991; Aiba et al., 1994, Goda and Stevens, 1996). The hippocampus is a center for learning and memory that receives abundant cholinergic innervation and has a high density of nicotinic acetylcholine receptors (nAChRs) (Wada et al., 1989; Woolf, 1991). We report t...

BACKGROUND AND PURPOSE Diffusion-weighted MR imaging and the trace apparent diffusion coefficient (ADC) provide important structural information about tissues. The purpose of this study was to investigate the relationship between trace ADC values and the enhancement pattern of multiple sclerosis (MS) lesions. METHODS Ninety-six lesions, identified in 24 patients with MS, were characterized by...