Biomedical subjects

Yoichi Ando

Publications and source records attributed to Yoichi Ando.

39 records · Page 3Linked to original sources

PubMed2002

Low-temperature electronic heat transport in La2-xSrxCuO4 single crystals: unusual low-energy physics in the normal and superconducting states.

The thermal conductivity kappa is measured in a series of La2-xSrxCuO4 (0 < or = x < or = 0.22) single crystals down to 90 mK to elucidate the evolution of the residual electronic thermal conductivity kappa(res), which probes the extended quasiparticle states in the d-wave gap. We found that kappa(res)/T grows smoothly, except for a 1/8 anomaly, above x approximately 0.05, and shows no discontinuity at optimum doping, indicating that the behavior of kappa(res)/T is not governed by the metal-insulator crossover in the normal state; as a result, kappa(res)/T is much larger than what the normal-state resistivity would suggest in the underdoped region, which highlights the peculiarities in the low-energy physics in the cuprates.

Journal Article↗

PubMed2002

Propagation of repetitive alpha waves over the scalp in relation to subjective preferences for a flickering light.

Paired-comparison tests were performed to examine subjective preferences for a flickering light. Electroencephalograms were then recorded from seven electrodes (10-20 system) during presentations of the most and least preferred flickering-light conditions. As a way of investigating the flow of alpha waves on the scalp over both the left and right hemispheres in relation to subjective preference, the alpha waves were analyzed by means of the cross-correlation function (CCF). The maximum value of the CCF, /phi(tau)/(max), between the alpha waves measured at different electrodes and its delay time, tau(m), were analyzed. Results show that the most preferred flickering light has a significant larger /phi(tau)/(max) than the least preferred flickering light, and that /phi(tau)/(max) decreases with increasing distance between comparison (O(1) or O(2)) and test electrodes. On the other hand, the delay time of the maximum value of the CCF, tau(m), increases with the distance between comparison and test electrodes.

Adult↗

PubMed2002

Relationship between subjective preference and alpha-wave activity in relation to temporal frequency and mean luminance of a flickering light.

Human cortical responses corresponding to the subjective preference for a flickering light under varying temporal frequency and mean luminance were investigated. Paired-comparison tests were performed to examine the subjective preference for a flickering light, and electroencephalograms (EEGs) were recorded from six electrodes (10-20 International Electrode Placement System) during presentations of the most-preferred and least-preferred flickering lights. The results showed a positive correlation between subjective preference and the effective duration of the autocorrelation function of the alpha waves measured at the visual cortex (O1 and O2 electrodes).

Adult↗