Search

A novel, compact, and tunable lithium niobate (LN) planar waveguide loop structure composed of two Y junction reflectors is proposed for optical and radio frequency signal processing applications. The preliminary device shows a high quality factor of 6.5 x 10(4), due to the low propagation loss of the titanium-diffused LN waveguide. The tunability of the loop by electric field is estimated.

Abstract Nuclear receptors represent a very good family of protein targets for the prevention and treatment of diverse diseases. In this study, we screened natural compounds and their derivatives, and [...]

In this paper, a preliminary evaluation study is conducted, which aiming to investigate the radar cross-section (RCS) value that is capable to be used as an input parameter for Artificial Neural network (ANN) backpropagation for foreign object debris (FOD) size classification. The experimental work procedure for dataset acquisition is described. The FOD simulator is used as the FOD target which is made of metal cylinder shape with nine various dimensions and its RCS is defined by using Maxwell’s equation. The location varying backscattered electromagnetic field from each target is measured for RCS calibration purposes. It is found that by using the received signal from radar, which is the RCS of the target and its locations, it can be utilized as input parameters of backpropagation algorithms. The ANN classification application is to define its size by the ranges; small (-30.99 to -21 dBsm), medium (-20.99 to -11 dBsm), and large (-10.99 to 0 dBsm). The interference signal getting from measurement (22.46 to 25.2 dBsm) exhibited good reflectivity behavior. The acquired input showed to be useful for ANN for FOD size classification. [ABSTRACT FROM AUTHOR]

High‐speed data transfer and high‐performance imaging can be realized by using radio‐waves in high‐frequency bands, such as millimeter‐waves and THz‐waves, where wide frequency bands are available. However, the cell size would be smaller than a few hundred meters, due to large free space propagation loss and large atmospheric attenuation. Thus, many base stations, which are connected by networks, are required to offer nationwide or global network services by such high‐frequency radio‐bands. The networks would be constructed by various transmission media including optical fibers and fixed wireless links, where many media converters are required. This paper reviews various technologies for seamless bridges between radio and optical links. For the time being, congestion of radio spectrum in THz bands is not significant. However, if we look at the history of radio‐wave technologies, spectral congestion has been high even in newly developed high frequency bands. In active radio services in millimeter‐wave or THz‐wave bands, interference mitigation with passive services such as radio astronomy and Earth observation satellites is an important issue, as of now. This paper describes research trends of THz‐wave technologies from the point of view of a figure of merit defined by a product of the carrier frequency and spectral efficiency, to discuss the significance of spectral efficiency enhancement in the high‐frequency region. Analysis of power consumption of short‐distance radio systems is also shown to discuss expected performance of THz‐wave links. Key Points: Seamless networks consisting of high‐speed wireless and wired links can offer nationwide or global high‐performance radio servicesMultimode radio‐over‐fiber can be used for short‐distance waveform transfer in future mobile networksInterference mitigation is an important issue even in THz bandsHigh‐speed wireless links can offer low‐power consumption data transfer [ABSTRACT FROM AUTHOR]

What is known and objective This study aimed to elucidate the pharmacokinetics of erlotinib in Japanese patients with advanced non-small cell lung cancer ( NSCLC) and to investigate the relationship between erlotinib exposure and the occurrence of interstitial lung disease ( ILD)-like events. Methods Population pharmacokinetics analysis was performed using nonlinear mixed-effects modelling software ( NONMEM) based on 348 plasma samples from 97 patients obtained in two phase II clinical studies. Individual empirical Bayesian estimates ( EBEs) of apparent oral clearance ( CL/F) and Cmax were compared between the patients who developed and did not develop ILD-like events. Results A 1-compartment model with first-order absorption and first-order elimination was used to describe the plasma concentrations of erlotinib. The estimated population pharmacokinetics parameters were as follows: 4·71 L/h for CL/F, 163 L for apparent volume of distribution (Vc/F) and 1·97 h−1 for absorption rate constant ( Ka). Total bilirubin ( TBIL) and alpha 1-acid glycoprotein ( AGP) were identified as statistically significant covariates for CL/F. No differences in CL/F and Cmax were observed between the patients with ILD-like events and those without ILD-like events. What is new and conclusions A population pharmacokinetics model of erlotinib was developed and validated in Japanese patients. There was no relationship between exposure of erlotinib before the occurrence of ILD-like events and the occurrence of ILD-like events when erlotinib was administered at the same dosage. The high plasma concentration of erlotinib reported in patients after the onset of ILD-like events may be explained by CL/F decrease which occurs along with increasing levels of AGP which was identified as a covariate for CL/F. [ABSTRACT FROM AUTHOR]

We propose wireless millimeter-wave (MMW) to lightwave (LW) signal converters using a simple planar antenna on LiNbO3 optical crystal. The LiNbO3 crystal is bonded with low-k dielectric material as the substrate. The simple planar antenna is formed with a rectangular patch antenna with a gap and inserted between the bonded structure. An optical waveguide are fabricated on the LiNbO3 crystal and located between the gap. The LiNbO3 crystal has relatively lower dielectric constant compared with a LiTaO3 crystal. Larger antenna size can be obtained using the LiNbO3 crystal. Additionally, an electro-optic coefficient of the LiNbO3 crystal is larger than the LiTaO3 crystal. Therefore, conversion efficiency enhancement can be achieved using the propose device. [ABSTRACT FROM AUTHOR]

We achieved record 109-Tb/s transmission over 16.8 km, using space division multiplexing (SDM) together with conventional multiplexing technology. 7-core SDM, 97 WDM (100-GHz spacing), 2 × 86 Gb/s PDM-QPSK signals were used. The spectral efficiency was 11.2 b/s/Hz. SDM transmission was realized using a multi-core fiber with ultra-low-crosstalk (less than -90.0 dB/km at 1550 nm) and high performance SDM MUX/DEMUX. The overall SDM crosstalk of -53 dB caused almost no penalty for the PDM-QPSK transmission. [ABSTRACT FROM PUBLISHER]

We discuss the generation, detection, and long-haul transmission of single-polarization differential quadrature phase shift keying (DQPSK) signals at a line rate of 53.5 Gbaud to support a net information bit rate of 100 Gb/s. In the laboratory, we demonstrate 10-channel wavelength-division multiplexed (WDM) point-to-point transmission over 2000 km on a 150-GHz WDM grid, and 1200-km optically routed networking including 6 reconfigurable optical add/drop multiplexers (ROADMs) on a 100-GHz grid. We then report transmission over the commercial, 50-GHz spaced long-haul optical transport platform LambdaXtremereg. In a straight-line laboratory testbed, we demonstrate single-channel 700-km transmission, including an intermediate ROADM. On a field-deployed, live traffic bearing Verizon installation between Tampa and Miami, Florida, we achieve 500-km transmission, with no changes to the commercial system hardware or software and with 6 dB system margin. On the same operational system, we finally demonstrate 100-Gb/s DQPSK encoding on a field-programmable gate array (FPGA) and the transmission of real-time video traffic. [ABSTRACT FROM PUBLISHER]

We demonstrate record 25.6-Tb/s transmission over 240 km using 160 WDM channels on a 50-GHz grid in the C+L bands. Each channel contains two polarization-multiplexed 85.4-Gb/s RZ-DQPSK signals, yielding a spectral efficiency of 3.2b/s/Hz in each band. [ABSTRACT FROM PUBLISHER]

In order to realize a future 100-Gb Ethernet (100 GbE) transport, 100-Gb/s transmission without 100-GHz-class electronics and optical time-division-multiplexing technique was demonstrated. By using a differential quadrature phase-shift-keying (DQPSK) modulation format and commercially available electronics, 2- and 50-km transmissions of 100-Gb/s signal were successfully achieved over a standard single mode fiber. The receiver sensitivity, chromatic dispersion, and differential group delay tolerances of 100-Gb/s DQPSK signal were also evaluated. Through these evaluations, the possibility of DQPSK modulation for future 100-GbE transport is verified [ABSTRACT FROM PUBLISHER]

A high-speed external modulation scheme for optical continuous-phase frequency-shift keying (CPFSK) is presented. In external frequency-shift keying (FSK) modulation using single-sideband modulation technology, an optical upper/lower sideband (USB/LSB) component with respect to a carrier frequency is selectively generated. However, the FSK-modulated signal has phase discontinuities at the timings of frequency shifts. To overcome the problem, we propose a synchronous control technique that enables continuous phase modulation. In the external CPFSK modulation, the USB/LSB is allowed to shift to the other state when their phases coincide with each other. It is shown that CPFSK with a zero-to-peak frequency deviation of 0.5times(bit rate) is achieved with this synchronous control. Occupant bandwidth is less than half that of the externally modulated incoherent FSK with phase discontinuities. At a modulation speed of 10 Gb/s, higher order sidelobes are highly suppressed by more than 20 dB at the 20-GHz offset, comparing to a conventional binary phase-shift keying (BPSK). By the use of a Mach-Zehnder interferometer with balanced photodetection, receiver sensitivity is 3-dB greater than that of an on-off keying, as well as a BPSK. In this paper, we report on the experimental demonstration of CPFSK modulation/demodulation. A six-channel wavelength-division-multiplexed, 10-Gb/s CPFSK modulation/demodulation was successfully demonstrated [ABSTRACT FROM PUBLISHER]

The hydrolysis of olive oil catalyzed by Chromobacterium viscosum lipase (EC 3.1.1.3) in a water/isooctane two-phase system was carried out both under ultrasound and conventional stirring. The maximum activity of lipase in the ultrasonicated system was 1.75 times higher than that in the stirred system. The lipase activity was dependent on ultrasonic power and volume ratio of isooctane to water. The optimum reaction temperature in both systems was around 25°C. The stability of lipase at 25°C in the ultrasonicated system decreased more rapidly than that in the stirred system. In the presence of exogenous oleic acid, however the half-life of lipase in the ultrasonicated system was improved to a value, which was respectively half and twice of that in stirred systems with and without oleic acid. The maximum reaction rate ( V max ) was increased by ultrasonication whereas the Michaelis constant ( K m ) remained unaltered. [ABSTRACT FROM AUTHOR]

We analyzed the CD16+CD57– lymphocyte subset, which is considered to have strong natural killer (NK) cell activity, in peripheral blood from patients with chronic immune-mediated neuropathies and patients with other neurological diseases. We found that the ratio of CD16+CD57– NK cells to total lymphocytes was increased in 4 of 6 patients with multifocal motor neuropathy (MMN) with persistent conduction block. Since the CD16 molecule is an Fc receptor for immunoglobulin G (IgG), high-dose intravenous immunoglobulin (IVIg) may interfere with CD16+CD57– NK cells via Fc receptor blockade. In addition, cyclophosphamide (Cy) is often used to suppress NK cells. Therefore, our findings may partly account for the effectiveness of IVIg or Cy, which is the current treatment of choice for MMN. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We described a novel optical label swapping (OLS) technique for optical packet systems using frequency-shift-keying (FSK) optical labeling. High-speed optical FSK signal can be generated by using an external FSK modulator consisting of four optical phase modulators. The FSK modulator was based on optical single-sideband (SSB) modulation technique, and comprised of traveling-wave electrodes for high-speed frequency switching. We demonstrate 10 Gbps FSK transmission, and simultaneous modulation by FSK and intensity modulation (IM). OLS using double-sideband modulation was also demonstrated, where this technique can be used for a bundled wavelength-domain-multiplexing (WDM) channels without using an array of pumping light sources. [ABSTRACT FROM PUBLISHER]

Focuses on an autotrophic continuous denitrification process, using hydrogen generated by electrolysis with activated carbon anodes, was experimentally demonstrated to be an effective nitrate removal process. How several fixed bed columns with polypropylene packing and honeycomb shaped activated carbon anodes and stainless rod cathodes were set in a thermostat chamber at 30?C, and potassium nitrate enriched tap water as influent was supplied at various flow rates and electric currents.

Reports that in order to confirm the usefulness of the nitrogen (N) stable isotope ratio of periphyton (mainly composed of attached algae) as an indicator for monitoring the N sources in river watersheds, we measured the isotope ratio of periphyton along the Chikuma River. How in the river, both the concentrations of dissolved total nitrogen (DTN) increased downstream.

We investigated reciprocating optical modulation (ROM) for millimeter-wave generation. The system was composed of an optical phase modulator and a pair of optical filters. A lightwave modulated by V-band millimeter waves was obtained from a 5-GHz electric signal. The spectrum linewidths of the generated 60-GHz millimeter wave was smaller than 300 Hz. By using mode-coupling equations, the spectra of the output lightwave were theoretically calculated. It was shown that the spectra depend on the optical path length between the two optical filters, so that harmonic generation and mixing with baseband signals can be obtained simultaneously. Intensity modulation of the generated millimeter wave was demonstrated by applying a baseband signal to the modulator without using another electric or optical modulator. [ABSTRACT FROM PUBLISHER]

Severely vitamin B-12 (B-12)-deficient rats were produced by feeding a B-12-deficient diet. The status of B-12 deficiency was confirmed by an increase in urinary methylmalonate excretion and decreases in liver B-12 concentrations and cobalamin-dependent methionine synthase activity. Rat liver methionine synthase existed almost exclusively as the holoenzyme. In B-12-deficient rats, the level of methionine synthase protein was lower, although the mRNA level was not significantly different from that of control rats. When methylcobalamin, the coenzyme for methionine synthase, was administered to the B-12-deficient rats, growth, liver B-12 concentrations and urinary excretion of methylmalonate were reversed although not always to control (B-12-sufficient) levels in a short period. During this recovery process, methionine synthase activity and its protein level increased, whereas the mRNA level was unaffected. We reported previously that rat apomethionine synthase is very unstable and is stabilized by forming a complex with methylcobalamin. Thus, the extremely low activity of methionine synthase in B-12-deficient rats may be related to effects on "coenzyme stabilization" (stabilization of the enzyme by cobalamin binding) rather than to changes in "coenzyme induction." [ABSTRACT FROM AUTHOR]

Metabolism of N-nitrosodimethylamine (NDMA), a hepatocarcinogen, and N-nitrosomethylbenzylamine (NMBeA), an esophageal carcinogen, was comparatively investigated in rat liver. When these nitrosamines (25 μmole/kg) were administered orally to rats, the clearance of NDMA from the serum and liver was faster than that of NMBeA. The metabolic decomposition of NDMA by rat isolated hepatocytes was slower than that of NMBeA at high concentration (0.5 mM). However, at low concentration (6.7 μM) the metabolic decomposition of NDMA was faster than that of NMBeA. The ratio of NDMA demethylation to NMBeA demethylation and debenzylation by hepatic microsomes also changed depending on nitrosamine concentrations (1 μM to 1 mM), and low concentration of NDMA was demethylated rapidly. These results suggest that NDMA is metabolized to a methylating agent more effectively than NMBeA in liver, when carcinogenic doses of nitrosamines are administered. [ABSTRACT FROM PUBLISHER]