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Yokohama, Japan

Toin University of Yokohama is a private university in Aoba-ku, Yokohama, Kanagawa prefecture, Japan. Toin University of Yokohama was established in 1988. It offers degree programs in sports medicine, medical technology, engineering and law. Wikipedia.

Yoshida M.,University of Tokyo | Yoshida K.,Toin University of Yokohama
Molecular Human Reproduction | Year: 2011

The chemotaxis of sperm towards eggs is a widespread phenomenon that occurs in most forms of life from lower plants to mammals and plays important roles in ensuring fertilization. In spermatozoa, the attractants act as beacons, indicating the path leading to the eggs from the same species. The existence of species-specific sperm chemotaxis has been demonstrated in marine invertebrates; thus, sperm chemotaxis may be involved in preventing crossbreeding, especially in marine invertebrates with external fertilization. However, the mechanisms of sperm chemotaxis in mammalian species differ from those of marine invertebrates. In mammals, the attractant source is not the egg, but follicular fluids or cumulus cells and chemotactic behaviour is shown only in small populations of sperm. Nevertheless, the fundamental mechanisms underlying sperm chemotaxis are likely to be common among all species. Among these mechanisms, intracellular Ca2+ concentration ([Ca2+]i) is an important factor for the regulation of chemotactic behaviour in spermatozoa. Sperm attractants induce the entry of extracellular Ca2+, resulting in [Ca2+]i increase in the sperm cells. Furthermore, [Ca2+]i modulates sperm flagellar movement. However, the relationship between [Ca2+]i and the chemotactic response of a sperm flagellum is not well known. Investigation of the dynamic responses of sperm cells to their attractants is important for our understanding of the regulation of fertilization. Here, we reviewed sperm chemotaxis focusing on the mechanisms that regulate sperm flagellar beating during the chemotactic response. © The Author 2011. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. Source

Miyasaka T.,Toin University of Yokohama
Journal of Physical Chemistry Letters | Year: 2011

Sensitized mesoscopic solar cells can exhibit high performance and processability by the use of a thin semiconductor layer in combination with a sensitizer of superior light-harvesting ability. This combination is an important key toward the realization of high-efficiency flexible solar cells using solution-based, rapid roll-to-roll printing processes. To this goal, preparation of a binder-free TiO2 paste is presented as a key process to low-temperature plastic electrode fabrication. For the future challenges of printable sensitized solar cells, this Perspective is focused on the importance of sensitizer choice for thin TiO2 films with regards to optimum light harvesting, showing photovoltaic behaviors of organic dye sensitizers and lead halide perovskite nanocrystals as inorganic sensitizers. Further, the author offers a comparison of the light-harvesting ability between organic dye sensitizers and inorganic quantum dot size sensitizers based on optical extinction coefficients and the surface density of the sensitizer. © 2011 American Chemical Society. Source

We prospectively compared the anti-inflammatory and antidyslipidemic effects of fenofibrate and statins in rheumatoid arthritis (RA) patients. Forty-four RA patients [male (M) = 7, female (F) = 37] with dyslipidemia were enrolled in this 6-month study and randomly allocated to the fenofibrate (2 M + 21 F = 23) or statins (5 M + 16 F = 21) group. We measured blood chemistry (serum lipid profile, sugar, urate, and γ-glutamyl transpeptidase) and blood pressure 2 h after breakfast. Visual analog scale (VAS), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and prednisolone (PSL) dosage were also recorded immediately before and after the study. Fenofibrate, but not statins, significantly decreased serum levels of total cholesterol, low-density lipoprotein-cholesterol, and triglycerides (all p < 0.05). A significant improvement in VAS was observed in both the fenofibrate group (49.1 ± 24.7 → 14.7 ± 11.2; p < 0.0001) and the statins group (47.4 ± 29.7 → 20.2 ± 16.5; p < 0.001). PSL dosage significantly decreased only in the fenofibrate group (3.58 ± 2.68 → 2.00 ± 2.22 mg/day; p < 0.01). Significant correlation was observed between DVAS and DCRP in the fenofibrate group (p < 0.05). Fenofibrate showed more anti-inflammatory and antidyslipidemic activity than statins in RA. © Japan College of Rheumatology 2010. Source

Miyasaka T.,Toin University of Yokohama
Chemistry Letters | Year: 2015

Organo-lead halide perovskite compounds, otherwise called organicinorganic hybrid perovskite, represented by CH3NH3- PbI3, exhibit many rare functions as narrow-band-gap semiconductors that are superior in applications for photovoltaic power conversion as well as for high-gain photon-mode detection of visible light. In this review, photoelectric properties of solution-processed CH3NH3PbI3 films and future perspectives in low-cost device fabrication are discussed based on our investigations. © 2015 The Chemical Society of Japan. Source

Toyabe S.,Chuo University | Okamoto T.,Chuo University | Watanabe-Nakayama T.,Tokyo Institute of Technology | Taketani H.,Chuo University | And 2 more authors.
Physical Review Letters | Year: 2010

Molecular motors drive mechanical motions utilizing the free energy liberated from chemical reactions such as ATP hydrolysis. Although it is essential to know the efficiency of this free energy transduction, it has been a challenge due to the system's microscopic scale. Here, we evaluate the single-molecule energetics of a rotary molecular motor, F1-ATPase, by applying a recently derived nonequilibrium equality together with an electrorotation method. We show that the sum of the heat flow through the probe's rotational degree of freedom and the work against an external load is almost equal to the free energy change per a single ATP hydrolysis under various conditions. This implies that F1-ATPase works at an efficiency of nearly 100% in a thermally fluctuating environment. © 2010 The American Physical Society. Source

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