The Construction and Testing of a New Apparatus with Knudsen Effusion Method Designed for Low Vapor Pressure Measurements of POPs

A new apparatus with Knudsen effusion method especially designed for the vapor pressure measurements of dioxin congeners and other POPs is described. Crystalline benzoic acid was used to test the new designed apparatus. The vapor pressure and enthalpy results of the reference compound were found in good agreement with accepted literature data, even when using a small Knudsen cell for toxicity compounds in this study. (Received October 28, 2002

Recovery of Scandium from Chloride Media Using the Novel Ion Exchange Resin

Abstract -This study focused on separation and recovery of scandium from chloride solution using the new synthesized ion exchange resin. The resin containing glycol amic acid groups shows the possibility to recover scandium from chloride aqueous solutions. At pH 1, the adsorption selectivity of scandium can be obtained among the others metals. The kinetic adsorption of scandium by the resin was found slowly, and contact time 24 hours was chosen as a suitable time in this study. The elution of scandium from the loaded resin could be completed with 2 M HCl solution at 80 o C. The close process will be established based on the optimum parameters which are obtained throughout this investigation, and that process can be applied in metal extraction processing for recovery of scandium and the other rare earth metals using the novel ion exchange resin

Extracellular and intraneuronal HMW-AbetaOs represent a molecular basis of memory loss in Alzheimer's disease model mouse

<p>Abstract</p> <p>Background</p> <p>Several lines of evidence indicate that memory loss represents a synaptic failure caused by soluble amyloid β (Aβ) oligomers. However, the pathological relevance of Aβ oligomers (AβOs) as the trigger of synaptic or neuronal degeneration, and the possible mechanism underlying the neurotoxic action of endogenous AβOs remain to be determined.</p> <p>Results</p> <p>To specifically target toxic AβOs <it>in vivo</it>, monoclonal antibodies (1A9 and 2C3) specific to them were generated using a novel design method. 1A9 and 2C3 specifically recognize soluble AβOs larger than 35-mers and pentamers on Blue native polyacrylamide gel electrophoresis, respectively. Biophysical and structural analysis by atomic force microscopy (AFM) revealed that neurotoxic 1A9 and 2C3 oligomeric conformers displayed non-fibrilar, relatively spherical structure. Of note, such AβOs were taken up by neuroblastoma (SH-SY5Y) cell, resulted in neuronal death. In humans, immunohistochemical analysis employing 1A9 or 2C3 revealed that 1A9 and 2C3 stain intraneuronal granules accumulated in the perikaryon of pyramidal neurons and some diffuse plaques. Fluoro Jade-B binding assay also revealed 1A9- or 2C3-stained neurons, indicating their impending degeneration. In a long-term low-dose prophylactic trial using active 1A9 or 2C3 antibody, we found that passive immunization protected a mouse model of Alzheimer's disease (AD) from memory deficits, synaptic degeneration, promotion of intraneuronal AβOs, and neuronal degeneration. Because the primary antitoxic action of 1A9 and 2C3 occurs outside neurons, our results suggest that extracellular AβOs initiate the AD toxic process and intraneuronal AβOs may worsen neuronal degeneration and memory loss.</p> <p>Conclusion</p> <p>Now, we have evidence that HMW-AβOs are among the earliest manifestation of the AD toxic process in mice and humans. We are certain that our studies move us closer to our goal of finding a therapeutic target and/or confirming the relevance of our therapeutic strategy.</p

Brain Cortical Mapping by Simultaneous Recording of Functional Near Infrared Spectroscopy and Electroencephalograms from the Whole Brain During Right Median Nerve Stimulation

To investigate relationships between hemodynamic responses and neural activities in the somatosensory cortices, hemodynamic responses by near infrared spectroscopy (NIRS) and electroencephalograms (EEGs) were recorded simultaneously while subjects received electrical stimulation in the right median nerve. The statistical significance of the hemodynamic responses was evaluated by a general linear model (GLM) with the boxcar design matrix convoluted with Gaussian function. The resulting NIRS and EEGs data were stereotaxically superimposed on the reconstructed brain of each subject. The NIRS data indicated that changes in oxy-hemoglobin concentration increased at the contralateral primary somatosensory (SI) area; responses then spread to the more posterior and ipsilateral somatosensory areas. The EEG data indicated that positive somatosensory evoked potentials peaking at 22 ms latency (P22) were recorded from the contralateral SI area. Comparison of these two sets of data indicated that the distance between the dipoles of P22 and NIRS channels with maximum hemodynamic responses was less than 10 mm, and that the two topographical maps of hemodynamic responses and current source density of P22 were significantly correlated. Furthermore, when onset of the boxcar function was delayed 5–15 s (onset delay), hemodynamic responses in the bilateral parietal association cortices posterior to the SI were more strongly correlated to electrical stimulation. This suggests that GLM analysis with onset delay could reveal the temporal ordering of neural activation in the hierarchical somatosensory pathway, consistent with the neurophysiological data. The present results suggest that simultaneous NIRS and EEG recording is useful for correlating hemodynamic responses to neural activity