Contamination levels of PCDDs, PCDFs and Co-PCBs in commercial baby foods in Japan

To examine dioxin contamination in commercial baby foods in Japan, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on 102 varieties of baby foods obtained from supermarkets in 2001-2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from < 0.001 to 0.135 pg-TEQ/g wet weight when undetected or trace levels of congeners were taken as zero. Among 102 samples tested, 26 samples exceeded 0.010 pg-TEQ/g. The highest TEQ value was for "sardine, vegetables" (0.135 pg-TEQ/g), followed by "Japanese radish (daikon), sardine" (0.080 pg-TEQ/g). Thus, dioxins were detected at low levels in baby foods containing animal products such as fishes and/or dairy products.     

Uniformity of gallium doped zinc oxide thin film prepared by pulsed laser deposition

Recently, transparent conducting oxide thin films have attracted attention for the application to transparent conducting electrodes. In this work, we evaluated the uniformity of electrical, optical and structural properties for gallium doped zinc oxide thin films prepared on the 10 × 10 cm² silica glass substrate by pulsed laser deposition. The resistivity, carrier concentration, mobility, bonding state and atomic composition of the film were uniform along in-plane and depth direction over the 10 × 10 cm² area of the substrate. The film showed the average transmittance of 81-87%, resistivity of 1.4 × 10^− 3 Ω cm, carrier concentration of 9.7 × 10²⁰/cm³ and mobility of 5 cm²/Vs in spite of the amorphous X-ray diffraction pattern. The gradual thickness distribution was found, however, the potential for large-area and low temperature deposition of transparent conducting oxide thin film using pulsed laser deposition method was confirmed.     

Optical measurement in carbon nanotubes formation by pulsed laser ablation

Carbon nanotubes (CNTs) were produced by laser ablation of a graphite composite target in argon and nitrogen ambient gas. To investigate the effect of nitrogen gas on CNTs formation, the plasma plume was examined using optical emission spectroscopy. The vibrational temperature of C₂ molecules was estimated by fitting of a Swan band spectrum. The temperature in N₂ ambient gas is lower than that in Ar ambient gas. In a nitrogen atmosphere, the spectrum intensity of C₂ Swan band was enhanced and CN violet system was also observed. Soot collected in the reaction tube was observed using FE-SEM and TEM. The soot deposited in the nitrogen gas contained more bundled CNTs than those in Ar ambience.     

A master-slave control system for a semi-autonomous underwater vehicle-manipulator system

Underwater vehicle-manipulator systems (UVMS) are expected to play an important role in ocean exploration. It is considered that UVMS will be operated by both automatic and manual control. We have proposed an automatic control method. In this article, we propose a master-slave system for a UVMS. The effectiveness of the proposed master-slave control system is demonstrated by using a floating underwater robot with a 2-link manipulator.     

Effect of chlorphentermine on incorporation of [14C]choline in the rat lung phospholipids

The effect of chlorphentermine (CP) treatment (50 mg/kg/ day, per os [po]) on the incorporation of [¹⁴C]choline into rat lung phospholipid was studied.Total phospholipid content was increased 2.0-fold and 1.7-fold after seven and 14 days, respectively, compared with the pair-fed rats. The incorporation of [¹⁴C]choline into phosphatidylcholine (PC) was significantly inhibited by either seven or 14 days of CP treatment. Nevertheless, the PC content was significantly increased by day 7 and stayed elevated at day 14 of CP treatment. Choline and phosphorylcholine contents were significantly decreased by the CP treatment. These results suggest that the higher accumulation of PC is due to inhibition of enzymes involved in the hydrolysis of phospholipids rather than to a stimulation of the phospholipid synthesis. Presented in part at the SOT Meeting, Atlanta, GA, March 1984 (abstracted inThe Toxicologist 4[1], 64).     

Macroscopic and pathohistological investigation of endarterial plaque after intraoperative balloon dilatation of the carotid artery during carotid endarterectomy

Twelve patients associated with stenosis of the extracranial carotid artery underwent intraluminal balloon dilatation during carotid endarterectomy (CEA). There were 11 men and 1 woman, and age ranged from 56 to 73 years old. The rate of stenosis, shown by angiography, in each patient was from 60 to 85% in width. After securing carotid blood flow by a T-shaped shunt tube, a balloon catheter was inserted from the exposed common carotid artery into the internal carotid artery. The balloon was inflated three or four times with 2.5-3.5 atm. for 30-40 seconds. Immediately after balloon dilatation, endoscopic investigation was performed (Wolf; hard type endoscope, 2.7 mm diameter). Then CEA was performed using the usual procedure. The removed endarterial plaque was investigated pathohistologically. In macroscopic and endoscopic findings, there were 6 patients with mural thrombosis, 4 patients with laceration of the intima, and one patient with outflow of atheroma from the intima. Only 3 patients had increase in lumen after balloon dilatation. In pathohistological appearance, all patients had a moderate degree of fibrosis, calcification, and atheroma in the cross section of the plaque. Ten patients had intramural hemorrhage. Three typical patients were revealed by the use of angiographical, ultrasonographical, endoscopic, and pathohistological presentation. Case 10 showed laceration of the intima by balloon dilatation, and had moderate increase in lumen size macroscopically and endoscopically. There were moderate cases of fibrosis, calcification, atheroma, and intramural hemorrhage. Dilatation of the lumen seemed to be accomplished by a decrease in thickness of the atheroma and intramural hemorrhage. Case 8 demonstrated an increase in lumen size, but also laceration of the intima and outflow of atheroma from the arterial wall. There were much atheroma and large intramural hemorrhage in the intima, which might become a source of enbolism. Case 7 revealed no laceration of the intima and no increase in lumen size. Preoperative ultrasonography showed hyperechoic finding and postoperative pathohistological findings showed severe fibrosis and calcification, which were thought to have interrupted balloon dilatation. There have been small numbers of reports about pathohistological presentation after percutaneous transluminal angioplasty (PTA), because it is very difficult to take a specimen after PTA. In this report we were able to present the necessity of preoperative investigations by angiography, ultrasonography, and 3D-CT.     

Fusion Safety Research and Development in JAERI

This paper describes the current status and future plans of the fusion safety research and development regarding to the developments of the dust removal system and safety analysis code and the thermofluid experiments in the Japan Atomic Energy Research Institute (JAERI) for a fusion experimental reactor. The containment of the radioactive material is the key to achieve fusion safety. In the event of accidents, the source terms need to be evaluated with sufficient accuracy. Therefore, in JAERI, the dust characterization have been investigated and the dust removal system using electric force has been developed and tested. A safety analysis code including both thermal and plasma transient analyses under the various event sequences has been developed. Moreover, the preliminary experiments of thermofluid transients in the vacuum vessel such as Ingress of Coolant Event (ICE) and Loss of Vacuum Event (LOVA) have been started and the experimental results using preliminary LOVA/ICE apparatus during 1995–1996 are summarized in this paper.     

Sharp Absorption Peaks in THz Spectra Valuable for Crystal Quality Evaluation of Middle Molecular Weight Pharmaceuticals

Middle molecular weight (MMW) pharmaceuticals (MW 400~4000) are attracting attention for their possible use in new medications. Sharp absorption peaks were observed in MMW pharmaceuticals at low temperatures by measuring with a high-resolution terahertz (THz) spectrometer. As examples, high-resolution THz spectra for amoxicillin trihydrate, atorvastatin calcium trihydrate, probucol, and α,β,γ,δ-tetrakis(1-methylpyridinium-4-yl)porphyrin p-toluenesulfonate (TMPyP) were obtained at 10 K. Typically observed as peaks with full width at half-height (FWHM) values as low as 5.639 GHz at 0.96492 THz in amoxicillin trihydrate and 8.857 GHz at 1.07974 THz for probucol, many sharp peaks of MMW pharmaceuticals could be observed. Such narrow absorption peaks enable evaluation of the crystal quality of MMW pharmaceuticals and afford sensitive detection of impurities.     

Effect of non-uniform electron energy distribution function on plasma production in large arc driven negative ion source

Spatially non-uniform electron energy distribution function (EEDF) in an arc driven negative ion source (JAEA 10A negative ion source: 10 A NIS) is calculated numerically by a three-dimensional Monte Carlo kinetic model for electrons to understand spatial distribution of plasma production (such as atomic and ionic hydrogen (H(0)∕H(+)) production) in source chamber. The local EEDFs were directly calculated from electron orbits including electromagnetic effects and elastic∕inelastic collision forces. From the EEDF, spatial distributions of H(0)∕H(+) production rate were obtained. The results suggest that spatial non-uniformity of H(0)∕H(+) productions is enhanced by high energy component of EEDF.     

An approach to establishing a method for calculating inventory

In periodic review inventory systems, inventory is classified into cycle stock and safety stock. Cycle stock is defined as inventory that absorbs differences between supply and demand frequencies. It can be calculated without deficiency or excess because a method has been established for ensuring that the minimum on-hand inventory during a periodic review is zero. Safety stock is defined as inventory that absorbs various differences between supply and demand. Unlike for cycle stock, a method for calculating safety stock without deficiency or excess remains to be established. An approach is proposed to establishing a method for calculating inventory in which inventory is classified on the basis of the holding purpose and the calculation factors indicate solutions. This approach was applied to inventory held to absorb, on the basis of fluctuations in demand, the difference in terms of time and quantity between supply and demand. Stock held for this purpose is referred to as ‘fluctuation stock’. The objective is to establish a method for calculating fluctuation stock so that the minimum on-hand inventory during a periodic review is zero and to clarify the relationship between fluctuation stock and safety stock.