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151.
A modified Stroop color-word task has been developed to activate the prefrontal cortex as a cognitive task and it has been tried to clarify whether change in the cerebral hemodynamics after ingesting caffeine is associated with change in performance on the modified Stroop task in young male subjects. In this modified task, subjects were instructed to quickly select a colored disk on a computer screen in response to an instruction, i.e. “color” or “meaning”, presented simultaneously with one color word at each trial. The color of the presented color word was discordant with the meaning of the word. Relative changes in blood volume and oxygenation in the prefrontal association cortex were measured noninvasively using continuous-wave near-infrared spectroscopy. The results showed that caffeine ingestion decreased blood volume and oxygenated hemoglobin concentration in the brain during the modified Stroop task, and that the individual change in the latter was related to change in performance on the task following caffeine ingestion. 相似文献
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154.
Tadashi Nishio Rie Suzuki Yuko Tsukada Hideko Kanazawa Teruo Okano Takako Miyabe-Nishiwaki 《Journal of chromatography. A》2009,1216(44):7427-7432
A new method for the quantitative analysis of monkey serum propofol, which is widely used as an anaesthetic agent, was developed by utilizing a temperature-responsive polymer of N-isopropylacrylamide (NIPAAm) and butyl methacrylate (BMA) as the stationary phase of HPLC–fluorescence detection. This poly(NIPAAm-co-BMA) copolymer undergoes a reversible phase transition from a hydrophilic to a hydrophobic microstructure when triggered by change in the temperature. Also this chromatographic system is possible to separate the analytes by using only water as a mobile phase. A pretreatment of the serum (80 μL) was only solid-phase extraction, and the recovery rate of propofol and internal standard was more than 77%, respectively. This method covered the calibration range from 0.5 μg/mL to 10 μg/mL and allowed a reproducible quantification of the serum propofol in administrated monkey serum. The intra- and inter-assay relative standard deviations were less than 14.1%. In addition, there was good relationship of the quantification values between the developed method and the widely used reversed-phase HPLC method. Our developed method has proven to be useful for a simple analysis of propofol in clinical practice, because the avoidance of complicated mobile phase preparation was possible, and only temperature changing could regulate the retention time of the analyte. In addition, by using water instead of fossil fuel, it is the ideal analytical method according to green chemistry. 相似文献
155.
Yoko Masuda Kozue Hirabayashi Keiko Sakuma Tadashi Nakanishi 《Colloid and polymer science》2002,280(5):490-494
The swelling behavior of poly(ethylene oxide) (PEO) gels in aqueous solutions of sodium dodecyl sulfate (SDS) with and without
NaCl was investigated. In the absence of NaCl, PEO gels with different degrees of cross-linking began to swell from a concentration
lower than the critical micelle concentration (cmc) of SDS, then showed sigmoidal enhancements of swelling in a higher SDS
concentration region until the degrees of swelling reached maximum values. The SDS concentration at which the swelling began
to appear was in reasonable agreement with the critical aggregation concentration (cac) value reported for the aqueous PEO
system. For the cases where NaCl was present, the swelling behavior of PEO gel was different from that when NaCl was absent
in the following way. The concentrations where the swelling begins to appear, and hence those where the degree of swelling
rises steeply, decreased with an increase in NaCl concentration. The ultimate degrees of swelling at higher concentration
regions also decreased with an increase in the NaCl concentration. The lowering of the SDS concentrations at which the PEO
gel began to swell is in line with the decreases in the cmc of SDS solutions containing NaCl and also with the decreases in
the cac of PEO solution.
Electronic Publication 相似文献
156.
Yutaka Nagasawa Ayako Watanabe Yoshito Ando Tadashi Okada 《Journal of Molecular Liquids》2001,90(1-3):295-302
We have studied femtosecond ground state recovery dynamics of phenol blue (PB) by pump-probe spectroscopy with a time resolution of 33 fs. Multiexponential decay with time constants extending from 300 fs to 10 ps were observed. Some low frequency intramolecular quantum beats were also observed. Solvent dependence of these decays and beats are discussed. 相似文献
157.
Norihiro Kobayashi Pi Sun Yayoi Fujimaki Toshifumi Niwa Tadashi Nishio Junichi Goto Hiroshi Hosoda 《Analytical sciences》2002,18(12):1309-1314
Measurement of cortisol levels in body fluids is important for monitoring pituitary gland and adrenal functions. To develop a specific and standardized enzyme-linked immunosorbent assay (ELISA), a novel monoclonal anti-cortisol antibody has been generated using a reasonably designed haptenic derivative. Spleen cells were prepared from the BALB/c or A/J mouse, which had repeatedly been immunized with a conjugate of 4-(2-carboxyethylthio)cortisol (CET) and bovine serum albumin, to be fused with P3/NS1/1-Ag4-1 myeloma cells. After four fusion experiments, one hybridoma clone secreting a practical antibody has been established. The resulting monoclonal antibody CS#38 (isotype gamma1, kappa) showed an affinity constant (K(a)) for cortisol of 1 x 10(9) M(-1) and provided a practical calibration curve (detection limit, 0.26 ng per assay) in a homologous ELISA system employing horseradish peroxidase-labeled CET as a labeled antigen. Cross-reactivities with related C-21 steroids were acceptably low: 11-deoxycortisol (4.3%), cortisone (4.0%), corticosterone (1.9%), progesterone (1.6%), 17alpha-hydroxyprogesterone (12%), 6beta-hydroxycortisol (8.4%), and tetrahydrocortisol (< 0.1%). Urinary and serum cortisol levels of healthy volunteers were determined by this method after methylene chloride extraction to be 39.0 +/- 17.0 microg/day (n = 7) and 80.8 +/- 38.9 ng/mL (n = 10), respectively, both of which are in the reference range. 相似文献
158.
In this paper we show that an isometric immersion is isotropic in the sense of O'Neill if and only if it preserves logarithmic derivatives of first geodesic curvatures of some curves. 相似文献
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160.
The diffusion of protons in porous media was observed and evaluated using a pH-imaging microscope with a flat semiconductor. Small particles were packed on the sensing surface of the flat sensor, followed by the addition of a lactic acid droplet on the top of the packed particle layer. The pH distribution accompanied by the diffusion of lactic acid was visualized at the bottom of the layer using the flat sensor. The difference in the diffusion property was confirmed depending on the particle type. The effective diffusion coefficients of the lactic acid in some porous media were estimated by combining the experimental results and mathematical calculation. 相似文献