Diagnostics of Rovibrational Distribution of H2 in Low Temperature Plasmas by Fulcher-α band Spectroscopy - on the Reaction Ratesand Transition Probabilities

A novel fitting procedure is proposed for a better determination of H2 rovibrational distribution from the Fulcher-α band spectroscopy. We have recalculated the transition probabilities and the results show that they deviate from Franck-Condon approximation especially for the non-diagonal transitions. We also calculated the complete sets of vibrationally resolved cross sections for electron impact d^3IIu- X^3∑g transition based on the semi-classical Gryzinski theory. An example of experimental study confirms that current approach provides a tool for a better diagnostics of H2 rovibrational distribution in electronic ground state.     

Effect of tetracosahexaenoic acid on the content and release of histamine, and eicosanoid production in MC/9 mouse mast cell

6,9,12,15,18,21-Tetracosahexaenoic acid (24∶6n−3) was isolated from a brittle star, Ophiura sarsi Lütken, at>95% purity to evaluate its physiological functions. The effects of 24∶6n−3 on the production of leukotriene (LT)-related compounds such as LTB₄, LTC₄ and 5-hydroxyeicosatetraenoic acid, and the accumulation and release of histamine in an MC/9 mouse mast cell line were studied. We found that 24∶6n−3 could inhibit the antigen-stimulated production of LT-related compounds as well as other n−3 polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (20∶5n−3) and docosahexaenoic acid (22∶6n−3), which are major n−3 PUFA in fish oils; 24∶6n−3 was also shown to reduce the histamine content in MC/9 cells at 25 μM (27% reduction from the control), and the effect was diminished with increase of the fatty acid concentration (up to 100 μM). These two n−3 PUFA, 20∶5n−3 and 22∶6n−3, also reduced the histamine content (16 and 20% reduction at 25 μM, respectively), whereas arachidonic acid (20∶4n−6) increased it (18% increase at 25 μM). Spontaneous- and antigen-induced release of histamine was not influenced with these PUFA (at 25 μM). Ionophore-stimulated release of histamine was suppressed by the PUFA (13,9,15, and 11% reduction with 20∶4n−6, 20∶5n−3, 22∶6n−3, and 24∶6n−3, respectively). The patterns of the effects of 24∶6n−3 on the synthesis of eicosanoids and histamine content were more similar to those of 22∶6n−3 than 20∶5n−3. From these results, 24∶6n−3 can be expected to have anti-inflammatory activity and antiallergic activities similar to those of 22∶6n−3.     

Optical pulse generation using guided-wave electrooptic modulator with resonant electrodes and polarization reversal

This paper reports on optical pulse generation using a new guided-wave electrooptic (EO) phase modulator with long resonant electrodes and polarization reversal. Adopting polarization-reversal structure to a guided-wave EO modulator with long standing-wave resonant electrodes, high-efficiency optical modulation is obtained by the compensation of the transit-time effect. By operating a fabricated EO phase modulator with a large amplitude modulation signal, optical sidebands over 100 GHz were obtained. Furthermore, optical pulse trains of an /spl sim/ 25-ps pulsewidth and a 15.28-GHz repetition frequency were successfully obtained by controlling the generated optical sidebands by use of an optical synthesizer.     

Electron spin resonance studies on silver atoms in imogolite fibers

The formation and stabilization of reduced silver species in imogolite have been studied by electron spin resonance (ESR) spectroscopy. Ag-loaded imogolite samples after degassing and dehydration were γ-irradiated at 77 K and monitored by ESR as the temperature increased. Some samples were exposed to methanol vapour after dehydration. It was found that imogolite shows exceptional ability to stabilize silver atoms. In dehydrated Ag-imogolite silver atoms generated at low temperature remain stable at room temperature. Silver atoms are also formed in imogolite samples exposed to methanol. However, in contrast to silver agglomeration in molecular sieves and smectites exposed to methanol there is no indication of the formation of cationic silver clusters in Ag-imogolite. It is postulated that there are special trapping sites in imogolite structure which effectively stabilize silver atoms.     

Error correction and error detection techniques for wireless ATM systems

Error correction and error detection techniques are often used in wireless transmission systems. The Asynchronous Transfer Mode (ATM) employs Header Error Control (HEC). Since ATM specifications have been developed for high‐quality optical fiber transmission systems, HEC has single‐bit error correction and multiple‐bit error detection capabilities. When HEC detects multiple‐bit error, the cell is discarded. However, wireless ATM requires a more powerful Forward Error Correction (FEC) scheme to improve the Bit Error Rate (BER) performance resulting in a reduction in the transmission power and antenna size. This concatenation of wireless FEC and HEC of the ATM may effect cell loss performance. This paper proposes error correction and error detection techniques suitable for wireless ATM and analyzes the performance of the proposed schemes. This revised version was published online in June 2006 with corrections to the Cover Date.     

Proliferation and migration kinetics of stem cells in the rat fundic gland

The proliferation and migration of stem cells in the developing and adult rat fundic gland have been studied using BrdU immunohistochemistry and BrdU-GSA II (Griffonia-simplicifolia agglutinin-II) double staining. In the developing rat fundic gland, stem cells were first scattered throughout all levels of the epithelia and then concentrated in the depth of the pits. With the elongation and maturation of the fundic glands, stem cells left the gland base and moved upward. By 4 weeks after birth, the development of the fundic gland was completed and stem cells were confined to a narrow proliferative zone in the isthmus, reaching the adult distribution pattern. In the adult rat fundic gland, stem cells in the isthmus differentiated and migrated upward and downward, replacing the surface mucous cells and glandular cells respectively. For upward migration, it took about one week for stem cells to migrate from the isthmus to the surface. For downward migration, it took about two weeks for stem cells to migrate from the isthmus to the neck, and it took 30-36 weeks to reach the gland unit's blind end. Finally stem cells were lost at the deepest level of the glands. The results obtained by simple topographical distribution in the present experiment agreed well with those obtained by quantitative analysis, suggesting the usefulness of BrdU immunohistochemistry for cell kinetic studies.     

Applicability of spatially periodic boundary conditions to a numerical computation of flow in a channel obstructed by an array of square rods

Two‐dimensional numerical computation is performed for an unsteady laminar flow. Spatially the periodic boundary conditions are adopted in the streamwise direction and the adequacy of this treatment is studied by varying the computational domain size. The following results were obtained. The Strouhal number and the lift coefficient fluctuation amplitude may change with the domain size for the same flow conditions. Therefore, numerical simulation for a unitary periodic flow field, a “cell,” is valid for limited flow conditions, which depend on the Reynolds number, the blockage ratio of the rod, and its pitch. Research was carried out on a condition in which the numerical solution is determined uniquely, i.e., the calculated results do not change with the domain size, by paying attention to the change in the phase difference of the flow patterns between neighboring cells. The Strouhal number, the drag coefficient, and the lift coefficient fluctuation amplitude increase considerably with the blockage ratio in the calculated results. The lift coefficient fluctuation amplitude decreases slightly with the increase of the rod pitch. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(6): 357–370, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20027     

UV-Curable Transparent Adhesives for Fabricating Precision Optical Components

UV-curable transparent epoxy adhesives have been specifically developed for the fabrication of optical communictions precision devices. The newly developed adhesives using cylohexane type fluoro-epoxy as the base resin and speherical quartz filler have extremely low volume shrinkage of 1.2% during curing and the cured adhesives have low thermal expansion coefficient of less than 2 × 10^-5/°C. Sheets of the adhesives are colorless and transparent to visible light because the refractive index of the epoxy matrix resin is matched to that of the quatz filler. These highly transparent adhesives can be cured to a depth of more than 5 mm by using 10 mW/cm² UV-irradiation for 30 min. They also have high adhesive strength and good durability. Therefore, they can be used in the fabrication of optical components that require submicron positioning accuracy.     

Lack of correlation between the molecular size and the efficacy of lanthanides for potentiating GABAA currents in rat septal cholinergic neurons in culture

Actions of lanthanides were examined on GABAA receptor-activated responses in rat septal neurons in culture by using the whole-cell voltage-clamp technique. GABA (10 microM) currents were enhanced by these ions at 100 microM with an efficacy sequence of Pr3+ (1.11) > or = Lu3+ (1.07) > or = Gd3+ (1.02) > or = Er3+ (1.01) > or = La3+ (1: 40% increase) > or = Ce3+ (0.980) > or = Nd3+ (0.932) > or = Yb3+ (0.913) > or = Tb3+ (0.912), indicating the lack of correlation between the potentiating efficacy and ionic size of lanthanides.