Anisotropic photoconduction in dye-sensitized Langmuir films

Lateral charge transport has been observed in Langmuir multilayer films with a surface-active merocyanine dye by measuring the photoconduction in a gap cell configuration. The lateral photoconductivity Δσ_∥ is found to be 10³–10⁴ times larger than the photoconductivity Δσ_⊥ in the normal direction evaluated for sandwich cells at higher levels of illumination. A square root dependence on intensity is observed for both photoconductivities at these higher intensity levels. On decreasing the light intensity, Δσ_∥ varies linearly, while Δσ_⊥ continues to obey the square root law. These results are consistent with the hopping model for multilayer systems which has so far been developed.     

Pediococcus pentosaceus NB-17 for probiotic use

The plant-derived Pediococcus pentosaceus NB-17 was isolated from Japanese traditional vegetable pickles. The production of cytokines from mouse spleen cells co-cultivated with heat-killed bacteria was investigated in vitro. The bacteria significantly induced secretion levels of interferon (IFN)-gamma and interleukin (IL)-12 p70, and suppressed IL-4 productions in ovalbumin (OVA) sensitized mouse spleen cells. Therefore, the bacteria could effectively stimulate immune activities and showed allergic inhibitory effects. Further study on acid tolerance was performed under simulated gastric conditions and NB-17 showed resistance to simulated gastric acidity at pH 3.0 and pH 2.5. Moreover, after oral administration of the intact cells to rats, bacterial colonies derived from feces were analyzed by random amplification polymorphic DNA (RAPD). It was confirmed that the administered strain NB-17 remained alive in feces. These results suggest the possibility to use the P. pentosaceus NB-17 as functional foods.     

Real-time estimation system of the gaze position based on an electrooculogram

This article describes an online eye-tracking method based on an electrooculogram (EOG) to estimate gaze position. The objective is to use a biomedical signal EOG as the input of a human-machine interface for both disabled and healthy people. In this study, features of horizontal and vertical EOG signals were extracted to estimate the gaze position. Compensation for time-shift and nonlinearity were applied to improve the performance of the estimation. The estimated locus of the moving eye was compared with the locus of the target, and the deviation was about 3 cm. The results can be applied in some raw tracking fields, such as online communication, EOG-based pointers, and so on.     

Effect of pre-deformation on the precipitation process and magnetic properties of Fe–Cu model alloys

The effect of pre-deformation on the precipitation process and magnetic properties of Fe–Cu model alloys was investigated. These specimens simulate irradiation embrittlement of nuclear reactor pressure vessel (RPV) steels. Fe–1 wt%Cu alloys with and without pre-deformation in solid-state solution were thermally aged at 773 K for various times and the evolution of hardness, conductivity, and microstructure were investigated. Pre-deformation enhanced Cu precipitation and caused precipitation at dislocations. The coercive force tended to decrease for the pre-deformed specimen and the underlying mechanism is discussed. The results obtained are related to the magnetic characteristics of irradiated RPV steels.     

Activation of the contractile mechanism in the anterior byssal retractor muscle of Mytilus edulis

1. The electrical and mechanical responses of the anterior byssal retractor muscle (ABRM) of Mytilus edulis to acetylcholine (ACh), high [K]O or the removal of external Ca were examined under a variety of conditions. 2. ACh (10(-6)--10(-3)M) produced contracture tensions larger than those produced by high [K]O (30-300 mM) for a given amount of depolarization. In Ca-free solution, the rate of decline of ACh-contractures was much smaller than that of K contractures, though both ACh- and K-contractures eventually disappeared. 3. 5-HT (10(-4)M) of procaine (1 mM) markedly reduced the height of ACh-contractures, but had little or no effect on K-contractures. The height of K contractures was markedly decreased by Mn ions (20 mM) or low pH (4-5), while ACh-contractures remained unaffected. 4. Partial replacement of [Na]o by choline (30-100 mM) reduced both ACh-induced depolarization and contracture tension, whereas K-contractures remained unchanged even after total replacement of [Na]o by choline. 5. ACh could produce little or no tension when applied during the relaxation phase of K-contractures, while high [K]o produced the maximal contracture tension when applied during the relaxation phase of ACh-contractures. 6. Following the removal of external Ca from solutions containing less than 10 mM-Mg, the ABRM showed a marked tension development associated with repetitive electrical activity superimposed on a gradual decline of membrane potential. 7. These results suggest that ACh-contractures are mainly due to the release of intracellularly stored Ca, while K-contractures are mainly associated with the inward movement of external Ca.     

The series elastic component and the force-velocity relation in the anterior byssal retractor muscle of Mytilus edulis during active and catch contractions

1. The length changes of the anterior byssal retractor muscle (ABRM) of Mytilus edulis, following step changes in load, were studied at various phases of active and catch contractions produced by acetylcholine. 2. The load-extension curves of the series elastic component (SEC) were found to be scaled down in proportion to the isometric tension immediately before step changes in load, but remain unchanged irrespective of whether the ABRM was in active or in catch contraction. 3. In hypertonic solutions the compliance of the SEC was reduced in the same manner as that of the SEC in frog skeletal muscle. 4. These results seem to favour the linkage hypothesis for the catch mechanism, though the SEC in the ABRM is suggested to be composed not only of the cross-linkages, but also of the compliance of the myofilaments.     

Contact-based stiffness sensing of human eye.

Goldmann applanation tonometry is commonly used for measuring intraocular pressure (IOP) to diagnose glaucoma. However, the measured IOP by conventional applanation tonometry is valid only under the assumption that all subjects have the same structural eye stiffness. This paper challenges in vivo measurement of eye stiffness with a noninvasive approach and investigates individual differences of eye stiffness. Eye stiffness is defined by the applied force and displacement of the cornea. The displacement is detected based on captured images by a high resolution camera. The experimental results show that the measured stiffness nicely matches the analytical result that is derived from a simple spherical deformation model with an internal pressure. However, some subjects have different eye stiffness even with the same IOP. IOP with abnormal stiffness may be over/underestimated by conventional applanation tonometry. The proposed eye stiffness measurement can help detect the misestimated eye and it contributes to the early detection of glaucoma.