The effects of leukotrienes C4 and D4 on ciliary activity of human paranasal sinus mucosa in vitro

The effects of leukotrienes C4 and D4 on ciliary activity of human paranasal sinus mucosa were investigated in vitro. Normal mucosa was surgically obtained from human paranasal sinuses and incubated in the form of tissue culture. Ciliated cells were magnified under an inverted microscope, and ciliary activity was photoelectrically measured. LTD4 progressively inhibited ciliary activity, and showed a more potent effect on ciliary activity compared to LTC4. The concentrations of LTC4 and LTD4 in the incubation medium were determined by radioimmunoassay when the mucosa was incubated with 10(-8) M LTC4. The concentration of LTD4 gradually increased and after 90 min reached the maximum of 0.71 x 10(-8) M, while that of LTC4 was reduced to about 10% of its initial concentration within 60 min. These results suggested the possible conversion of LTC4 to LTD4 on the mucosa, and that LTC4 can inhibit ciliary activity by means of LTD4.     

A Study of Shadowing on Indoor Visible-Light Wireless Communication Utilizing Plural White LED Lightings

White LED is considered as a strong candidate for the future lighting technology. We have proposed an optical wireless communication system that employs white LEDs for indoor wireless networks. In this system, LED is used not only as a lighting device, but also as a communication device. The transmitter has large optical power and large emission characteristics to function as lighting device. And the system has specific wireless channel impulse response differing from infrared wireless communication. In this paper, we discuss about shadowing effect on the system utilizing plural LED lightings including the performance of ISI based on the impulse response. We consider the downlink transmission based on TDMA and evaluate the shadowing effect caused by pedestrians with computer simulation. When the shadowing often occurs at 800 Mb/s, the performance of outage call duration rate and blocking rate are improved by using 3 LED lightings compared with 1 or 2 LED lightings. And, we show that the system with the optimal number of the LED lighting is robust against shadowing and can accommodate more calls. Toshihiko Komine was born in Shizuoka, Japan, on November 17, 1978. He received the B.E. and M.E. degrees in Information and Computer Science from Keio University, Yokohama, Japan, in 2001 and 2003 respectively. He is currently studying for the Ph.D. degree at Department of Information and Computer Science, Keio University. His current research interests are optical wireless communications and LED communications. Shinichiro Haruyama is a professor at Department of Information and Computer Science, Faculty of Science and Technology, Keio University, Yokohama, Japan. He received an M.S. in engineering science from University of California at Berkeley in 1983 and a Ph.D. in computer science from the University of Texas at Austin in 1990. He worked for Bell Laboratories of AT{&}T and Lucent Technologies, U.S.A from 1991 to 1996, and for Sony Computer Science Laboratories, Inc. from 1998 to 2002. His research interests include reconfigurable system, system design automation, wireless communication, and visible light communication. Masao Nakagawa was born in Tokyo, Japan in 1946. He received the B.E., M.E. and Ph.D. degrees in electrical engineering from Keio University, Yokohama, Japan, in 1969, 1971 and 1974 respectively. Since 1973, he has been with the Department of Electrical Engineering, Keio University, where he is now a Professor. His research interests are in CDMA, consumer Communications, Mobile communications, ITS (Intelligent Transport Systems), Wireless Home Networks, and Visible light Communication. He received 1989 IEEE Consumer Electronics Society Paper Award, 1999-Fall Best Paper Award in IEEE VTC, IEICE Achievement Award in 2000, IEICE Fellow Award in 2001. He was the executive committee chairman on International Symposium on Spread Spectrum Techniques and Applications in 1992 and the technical program committee chairman of ISITA (International Symposium on Spread Spectrum Techniques and Applications) in 1994. He is an editor of Wireless Personal Communications and was a guest editor of the special issues on “CDMA Networks I, II, III and IV” published in IEEE JSAC in 1994 (I and II) and 1996 (III and IV). He chairs the Wireless Home Link sub-committee in MMAC (Multimedia Mobile Access Communication Promotion Committee).     

Suppression of photo-induced dilation in cyanide treated hydrogenated amorphous silicon films

Effects of cyanide (CN) treatment with hydrogenated amorphous silicon (a-Si:H) films have been investigated. The decrease of ΔV/V was observed in cyanide treated a-Si:H films and the successive thermal annealing at 200°C after CN treatment induced the further reduction of the ΔV/V. XPS spectra show the indirect evidence that the cyanide species is present within 10 nm from the hydrogenated amorphous silicon surface. The results of CN treatment with a-Si:H solar cells are demonstrated.     

An effect of microstructure on the interface resistance between a perovskite-type oxide electrode and yttria-stabilized zirconia

The electrode characteristics of perovskite-type oxides, La_0.6Sr_0.4CoO₃ and La_0.6Sr_0.4MnO₃, on ceria-based oxide and stabilized zirconia were analysed by the a.c. impedance method. The ionic conductivities of the electrolyte and electrode conductivities from the a.c. impedance analysis agreed with those obtained from the current interruption and d.c. four-probe methods. Two semicircles from the charge transfer and diffusion processes appeared as the electrode resistance. The relative contribution of these two processes to the overall electrode resistance strongly depended on the microstructure of the electrode. The electrode microstructure could be controlled by the dispersion medium used for the electrode slurry. The La_0.6Sr_0.4MnO₃ electrode coated with n-butyl acetate slurry exhibited the smallest electrode resistance.     

Optical filtering to reduce chirping influence in LD wavelength conversion

The use of an optical filter to reduce chirping influence in LD wavelength conversion is demonstrated. A part of broadened spectrum of wavelength-converted light is eliminated by a narrow-band optical filter, and sensitivity degradation due to frequency chirping is reduced as a result. In an experiment using a fiber Fabry-Perot filter, the sensitivity was improved by about 1.5 dB in 1.55-/spl mu/m transmissions with normal dispersion fibers when an LD converter was biased at two times the threshold current.     

Blue electroluminescent devices withSrGa2S4:Ce for full-color display

In order to realize full-color electroluminescent (EL) displays, which are expected as a dominant candidate for the future multimedia flat panel display, blue EL devices with SrGa₂S₄:Ce have been prepared by molecular beam epitaxy (MBE). This paper proposes a novel deposition method employing Sr metal and Ga₂S₄ compound as the source materials. A single-phase SrGa₂S₄ layer is obtained in a Ga₂S₃/Sr flux ratio of 60 and at the growth temperature of 560°C. We have obtained the well-saturated blue with CIE color coordinates of x=0.14, y=0.14 and brighter blue EL devices made by optimizing the growth conditions in MBE. The maximum luminance of 70 cd/m² in comparison with the 3 cd/m₂ of our previous EL devices, is achieved at a driving frequency of 1 kHz     

Athermal silica-based arrayed-waveguide grating multiplexer

A temperature dependent channel wavelength shift in a silica-based arrayed-waveguide grating multiplexer is successfully suppressed from 0.95 to 0.05 nm in the 0-85°C temperature range, which means that it can be used in practical WDM systems without the need for temperature control