著者
Tomohiro Yako Yoshiki Kuse Shinsuke Nakamura Masamitsu Shimazawa Takashi Motomura Hideaki Hara
出版者
The Illuminating Engineering Institute of Japan
雑誌
Journal of Science and Technology in Lighting (ISSN:24323225)
巻号頁・発行日
vol.42, pp.29-32, 2019-03-27 (Released:2019-04-01)
参考文献数
12

Blue light emitting diode (LED) light is being used various devices for recent decades. Blue LED light has the 450–500 nm wavelengths, and high photon energy compared with green or red LED light. It is known that the exposure to blue LED light causes retinal photoreceptor cells damage. It is unknown whether the blue LED light cut particle containing lens has a protective effect against blue LED light-induced cell damage although the absorbance by colored lens shows a protective effect. Thus, the purpose of this study was to reveal that the protective effect of blue LED light cutting particle containing lens against photoreceptor and corneal epithelial cell damage induced by blue LED light exposure. We irradiated blue LED light to the mouse photoreceptor cells and human cornea epithelial cells with or without lens. The lens containing about one third blue LED light cutting particle (TECHPOLYMER) decreased production of reactive oxygen species and improved cell death rate and cell viability rate. These findings show that TECHPOLYMER containing lens may protect photoreceptor and cornea cells by reducing of reactive oxygen species.
著者
Joshua J Gooley
出版者
The Illuminating Engineering Institute of Japan
雑誌
Journal of Science and Technology in Lighting (ISSN:24323225)
巻号頁・発行日
vol.41, pp.69-76, 2018-03-20 (Released:2018-03-26)
参考文献数
46
被引用文献数
1

Light is the most important environmental signal for synchronizing human circadian rhythms. The circadian system is normally synchronized with the solar day, ensuring that the sleep–wake cycle and endocrine rhythms are timed appropriately. However, exposure to electrical lighting can also reset circadian rhythms. In this short review, we discuss properties of light stimuli that are important for resetting the human circadian system. The direction and magnitude of light resetting are circadian phase-dependent, with exposure to light in the early biological night resulting in a phase-delay shift of circadian rhythms, and exposure to light in the late biological night and early morning resulting in a phase-advance shift. Circadian resetting responses can be enhanced by increasing the irradiance or duration of the light stimulus, or by using short-wavelength blue light to activate intrinsically photosensitive retinal ganglion cells that express the photopigment melanopsin. This knowledge can potentially be applied to improve light therapy for circadian rhythm sleep disorders, and to help reset circadian rhythms in individuals exposed to shift work or jet lag.
著者
Ken-ichiro Suehara Takaharu Kameoka Atsushi Hashimoto
出版者
The Illuminating Engineering Institute of Japan
雑誌
Journal of Science and Technology in Lighting (ISSN:24323225)
巻号頁・発行日
vol.41, pp.12-21, 2018-03-20 (Released:2018-03-26)
参考文献数
33
被引用文献数
2

To construct a simple optical sensor for measurement of the sugar content in an aqueous solution, a bent optical fiber was used as the sensor. The attenuation ratio, i.e., the differences in the light intensity through the bent optical fiber when the sensitive part (bent part) was soaked in a reference material and sample solution, was closely related of the solute content in the samples. However, slightly difference in the light intensity were observed in the practical application because the sugar content in foods and other bio-systems was much lower than that in the tested samples. Therefore, we constructed a sensor system using a light emitting diode (LED), photo diode (PD) and simple electronic circuit as a differential amplifier. As a result, measurement of the sugar content ranging from 0 to 30 g/dm3 was successful and excellent agreement between the FT-IR method as the conventional method and the sensor method using an operational amplifier (OP-amp) was observed. In addition, the time courses of the sugar content and the uptake rate of plant cells were able to be calculated during the cultivation process. The process monitoring for the fermentation process management will be possible by using this sensor. These results suggested that the developed sensor using a bent optical fiber is applicable as a simple and disposable optical sensor.