Phospholipid hydroperoxides are detoxified by phospholipase A<Subscript>2</Subscript> and GSH peroxidase in rat gastric mucosa

The aim of this study was to determine the metabolic fate of phospholipid hydroperoxides (PLOOH) in rat gastric mucosa. Here we report evidence concering the mechanism for PLOOH detoxification in gastric mucosa homogenate. Analysis by the TLC blot technique showed that the gastric mucosa has the highest potential to eliminate 1-palmitoyl-2-linoleoyl-phosphatidylcholine hydroperoxides (PL-PtdChoOOH) compared with the intestinal mucosa and liver. Major products detected after incubation with gastric mucosa were the partially reduced linoleic acid hydroperoxides (LAOOH) and lysophosphatidylcholine, indicating the involvement of phospholipase A₂ (PLA₂) in the elimination pathway. Using unilamellar vesicles, we demonstrated that gastric mucosal PLA₂ does not distinguish between PLOOH and intact phospholipids. Although gastric mucosal PLA₂ activity efficiently eliminated excess amounts of PLOOH, the complete reduction of LAOOH was dependent on the supply of exogenous GSH. In a separate experiment, administration of egg yolk PtdChoOOH to rats for 6 d significantly elevated GSH peroxidase (GPx) activity in the gastric mucosa. We concluded that excess amounts of PLOOH are efficiently eliminated through the hydrolysis by PLA₂, and the subsequent reduction of FA hydroperoxide by GPx is the critical step for complete detoxification of oxidized phospholipids in the stomach.     

A concept of combined micro and macro fracture mechanics to brittle fracture

Real materials inevitably contain both stress concentrators as cracks or notches and as dislocations, that is, both macroscopic and microscopic one. From this viewpoint, a concept of combined micro and macro fracture mechanics is proposed for low-stress brittle fracture of steels.

     

Treatability evaluation of general organic matter. Matrix conception and its application for a regional water and waste water system

For the evaluation of the behaviors of general organic compounds in a regional water and waste water system and individual or combined water treatment processes, the authors have proposed to use some water quality indices in connection with scale grouping of organic compounds.The treatability of various types of treatment processes such as biological treatment, chemical coagulation and carbon adsorption were well evaluated with three comprehensive water quality indices such as TOC. TOC/E260 (absorbance at 260 nm) and E220 (absorbance at 220 nm) connected with the gel-chromatographic grouping after a water quality matrix conception.     

Low-loss fibre-pigtailed 256 channel arrayed-waveguide gratingmultiplexer using cascaded laterally-tapered waveguides

A fibre-pigtailed 25 GHz-spacing 256 channel arrayed-waveguide grating (AWG) module has been fabricated. The module was composed of an AWG chip with a Δ of 1.5%, a fan-out planar lightwave circuit (PLC) with a A of 0.75%, an input fibre and two 128 fibre arrays. To improve the coupling loss of the 256 output fibres, a new PLC-fibre connection using cascaded laterally-tapered waveguides was developed. The fibre-pigtailing loss is reduced to only 1.1 dB and a multiplexer with a low insertion loss of 1.9-3.9 dB is realised     

Continuous-wave operation of 1.30μm GaAsSb/GaAs VCSELs

1.30 μm VCSELs using GaAsSb quantum wells, which operate continuous-wave at and above room temperature (RT), are reported. A threshold current as low as 1.2 mA at RT and a maximum CW operating temperature of 70°C are demonstrated     

Low-threshold operation of 1.3-μm GaAsSb quantum-well lasersdirectly grown on GaAs substrates

GaAsSb quantum-well (QW) edge-emitting lasers grown on GaAs substrates were demonstrated. The optical quality of the QW was improved by optimizing the growth conditions and introducing a multi-QW to increase the gain. As a result, 1.27-μm lasing of a GaAs_0.66 Sb_0.34-GaAs double-QW laser was obtained with a low-threshold current density of 440 A/cm², which is comparable to that in conventional InP-based long-wavelength lasers. 1.30 μm lasing with a threshold current density of 770 A/cm² was also obtained by increasing the antimony content to 0.36. GaAsSb QW was found to be a suitable material for use in the active layer of a 1.3-μm vertical-cavity surface-emitting lasers     

Evaluation of implementation of thorium fuel cycle with LWR and MSR

In order to construct a sustainable society, it is necessary to consider fairness beyond generations and between countries. It is expected that Asian countries continue growing their economy and will result consuming more energy. More CO₂ emission is not acceptable.Nuclear power has many advantages for reducing CO₂ emission. However, it still has concerns of nuclear proliferation, radioactive waste and safety. It is necessary to overcome these concerns if nuclear power is expanded to Asian countries. Thorium utilization as nuclear fuel will be an opening key of these difficulties because thorium produces less plutonium, less radioactive waste. Safety will also be enhanced. The use of molten-salt reactor (MSR) triggered by plutonium supply from ordinary light water reactor (LWR) with uranium fuel will allow implementation of thorium fuel cycle with electricity capacity of about 446 GWe around at 2050.The other important sector in a view of sustainability is transportation. Transportation is essential for economy growth. Therefore it is inevitable to reduce CO₂ emission from transportation sector. Electric vehicle (EV) will be used as a major mobility instead of gasoline engine cars. Rare-earth materials such as neodymium and dysprosium are necessary for producing EV. These materials are expected to be mined from Asian countries. It is often obtained with thorium as by-product. Thorium has not been used as nuclear fuel because it is not good for nuclear weapon and it does not have fissionable isotopes. Recent global trend of nuclear disarmament and accumulation of plutonium from uranium fuel cycle can support starting the use of thorium.Thorium utilization will help both to provide clean energy and to produce rare-earth for clean vehicle. These will create new industries in developing Asian countries. An international collaborative framework can be established by supplying resource from developing countries and supplying technology from developed countries. “THE Bank (THorium Energy Bank)” is proposed here as one part of such a framework.