Preparation of biotinylated cypridina luciferase and its use in bioluminescent enzyme immunoassay

Cypridina luciferase, a well-known secretory enzyme involved in the bioluminescence of marine ostracod, is used to monitor gene expression in mammalian cells. Here we report the preparation of biotinylated Cypridina luciferase and its use in bioluminescent enzyme immunoassay (BLEIA). Recombinant Cypridina luciferase was expressed in yeast and successfully purified to near homogeneity. The luciferase was biotinylated with conventional biotinylation reagents, and the biotinylated lysine sites were determined by liquid chromatography-tandem mass spectrometry. The biotinylated luciferase was stable when stored at 4 degrees C. The stability of synthetic S-Cypridina luciferin was significantly improved by adding antioxidants to Tris-HCl buffer. The biotinylated luciferase and S-Cypridina luciferin were used in a model study of the immunoassay for interferon-alpha. The linearity of this immunoassay extended from 7.8 to 500 pg/mL interferon-alpha. Our results show that Cypridina luciferase is a very sensitive and versatile bioluminescent reporter.     

Direct observation of field emission in a single TaSi2 nanowire

The electric potential change in a single TaSi2 nanowire during field emission was visualized by means of electron holography. During the field emission, the interference fringes of the electron hologram were blurred locally between the TaSi2 nanowire and anode. This phenomenon was interpreted as being due to a change in the electric potential of approximately 1 V in the TaSi2 nanowire after each ballistic emission. The experiments on the single TaSi2 nanowire field emission behavior provide the useful information for understanding the field emission in the nano-field-emitting device.     

Fabrication of Lotus-Type Porous Carbon Steel Slabs by Continuous Casting Technique in Nitrogen Atmosphere

Lotus-type porous carbon steel slabs with long cylindrical pores aligned in one direction were fabricated by the continuous casting technique in a mixture gas of N₂ 0.8 MPa and Ar 1.7 MPa or in N₂ 2.5 MPa at various transfer velocities from 2.5 mm·min⁻¹ to 20 mm·min⁻¹. The pore size in lotus carbon steel fabricated in the mixture gas of nitrogen and argon was small and homogeneous, whereas the pore size in nitrogen had bimodal distribution depending on the transfer velocity. The large pores were observed mainly at the edge of the slab, which are considered to be merged of several inclined pores. The porosity depended on nitrogen partial pressure, which is explained by Sieverts’ law. The hardness of lotus carbon steel matrix increased, which was attributed to the solid-solution of nitrogen.     

Development of diode‐pumped solid‐state laser HALNA for fusion reactor driver

The diode‐pumped slab laser for inertial fusion energy driver has been demonstrated, which produces the 1053‐nm output energy of 10 J at 10 Hz. The glass slab laser amplifier has been pumped by quasi‐CW 290‐kW AlGaAs laser‐diode arrays at 803 nm. The optical system can compensate for thermal effects by use of zigzag optical propagation, image‐relayed telescope, and 45^° Faraday rotator. The output energy of 10.6 J at 1 Hz with the optical‐to‐optical conversion efficiency of 19.9% has been successfully obtained. Also, the 10‐Hz operation has been performed with an output energy of 5.1 J. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(2): 27–35, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20288     

Transmission characteristics of DFB laser modules for analogapplications

Analog transmission characteristics of highly linear 1.3- and 1.55-μm distributed feedback (DFB) laser modules are described. To obtain high-power and high-performance DFB lasers, the bias dependence of distortion characteristics is discussed. The carrier-to-noise ratio, the composite second-order distortion, and the composite triple beat of the DFB laser module which is developed for analog CATV applications are presented. The analog transmission characteristics, such as CNR degradation, after fiber transmission, dispersion-induced distortion, and the influence of reflection, have been made clear. The stable high linearity of the DFB laser also has been confirmed by the composite distortion measurement under an accelerated aging test     

A Study of Piston Friction Force in an Internal Combustion Engine

Quantitative estimation of friction losses in the initial design stage of an automobile engine is a crucial issue that determines the fuel economy and performance of the automobile. However, measurements and mathematical treatments of friction losses were difficult, and practical estimation methods were scarce.

This study was carried out due to such circumstances, with emphasis placed on the analysis of mechanism of friction losses of the piston system, and the introduction of practical equations for calculation of those friction losses.     

Action of 1-(11-selenadodecyl)-glycerol and 1-(11-selenadodecyl)-3-trolox-glycerol against lipid peroxidation

The antioxidant action on lipid peroxidation of the synthesized selenium compounds 1-(11-selenadodecyl)-glycerol (SeG) and 1-(11-selenadodecyl)-3-Trolox-glycerol (SeIrG, where Trolox=6-hydroxyl-2,5,7,8-tetramethylchroman-2-carboxylic acid) was investigated. We compared the reactivity of the selenium compounds toward peroxyl radicals and their inhibitory effect on lipid peroxidation, induced by several kinds of initiating species such as azo compounds, metal ions, and superoxide/nitric oxide in solution, micelles, membranes, and rat plasma. SeTrG, but not SeG, scavenged peroxyl radicals. SeG reduced methyl linoleate hydroperoxides in organic solution and in methyl linoleate micelles oxidized by ferrous ion (Fe²⁺)/ascorbic acid. In rat plasma SeG and SeTrG decreased the formation of lipid hydroperoxides generated by hydrophilic azo compounds. SeG and SeTrG spared α-tocopherol (α-TOH) consumption in multilamellar vesicle membranes oxidized by hydrophilic or lipophilic initiators, and only SeTrG spared α-TOH in superoxide/nitric oxide oxidized membranes. In rat plasma oxidized by radical initiators (either hydrophilic or lipophilic) or superoxide/nitric oxide, SeTrG suppressed α-TOH consumption, but SeG had no effect. The two selenium-containing compounds showed inhibitory effects on lipid peroxidation that depended on their structure, the medium where they acted, and the oxidant used.