Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals

A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects.     

Flexible Electronic Substrate Film Fabricated Using Natural Clay and Wood Components with Cross‐Linking Polymer

Requirements for flexible electronic substrate are successfully accomplished by green nanocomposite film fabricated with two natural components: glycol‐modified biomass lignin and Li⁺ montmorillonite clay. In addition to these major components, a cross‐linking polymer between the lignin is incorporated into montmorillonite. Multilayer‐assembled structure is formed due to stacking nature of high aspect montmorillonite, resulting in thermal durability up to 573 K, low thermal expansion, and oxygen barrier property below measurable limit. Preannealing for montmorillonite and the cross‐linking formation enhance moisture barrier property superior to that of industrial engineering plastics, polyimide. As a result, the film has advantages for electronic film substrate. Furthermore, these properties can be achieved at the drying temperature up to 503 K, while the polyimide films are difficult to fabricate by this temperature. In order to examine its applicability for substrate film, flexible electrodes are finely printed on it and touch sensor device can be constructed with rigid elements on the electrode. In consequence, this nanocomposite film is expected to contribute to production of functional materials, progresses in expansion of biomass usage with low energy consumption, and construction of environmental friendly flexible electronic devices.     

Low Temperature Study of the Mixed Donor System (TMTSF1-x TMTTF x )2PF6 : Crystal Structure, ESR and Transport Property

The phase diagram of the mixed donor quasi one-dimensional (Q1D) metallic system (TMTSF_1-x TMTTF _x )₂PF₆ has been studied. The study on the mixed donor systems helps us to establish not yet clarified phase boundaries in the Q1D system. We showed dependencies of properties on the donor mixing percentage for crystal parameters, resistivity, ESR(intensity and line width). ESR results show clear changes in the susceptibility and line width around 40 K. This result may indicate the existence of new boundary determined by the microscopic method on the Q1D phase.     

Accelerated solvent extraction for quantitative measurement of fatty acids in plasma and erythrocytes

Consumption of fish rich in n-3 highly unsaturated FAs (i.e., EPA and DHA) has been suggested to decrease the risk of lifestyle-related diseases such as coronary heart disease, cancer, diabetes, and dementia. Blood eevels of those FA are known appropriate biomarkers of both the corresponding dietary FA intakes and fish consumption. In place of traditional handwork methods for extracting FA, we performed an accelerated solvent extraction (ASE) for at least 13 selected FA in plasma and erythrocytes to measure them by GLC. The FA levels (concentrations and compositions) in 35–50 μL of plasma or erythrocytes were extracted by ASE and measured by GLC. Intra-and interassay coefficients of variation were≤6.0% for both blood materials, except with a minor group of FA (≤1.0% of total FA). When ASE was compared with two traditional handwork methods, FA levels in plasma from 18 healthy subjects were all coincident with very high Pearson's correlation coefficients for the three sets of the sama 18 samples (r≤0.85 to 0.95, P<0.0001), except for 18∶0 (r=0.59, P<0.01). Using ASE and GLC, we have developed a new method for determination the levels of FA in plasma and erythrocytes as biomarkers for dietary intake of fish, fat, and FA. This new method makes it feasible to measure small volumes of samples, automatically, quantitatively, routinely, easily, rapidly and cheaply, with acceptable precision and accuracy.     

Method for identification of mutant glutathione S-transferases conferring enhanced resistance to the anti-cancer drug chlorambucil

We screened library of mutant glutathione S-transferases (GSTs) in Escherichia coli by successive treatments with anti-cancer drug chlorambucil and identified mutant GSTs that conferred enhanced resistance to host against chlorambucil compared with wild-type GST. This study provides a method to develop enzymes with improved efficiency of detoxification against cytotoxic substances.     

Magnetic core properties and their thermal stability in a BCC Fe-Zr-B-Cu alloy with nanoscale grain size

A mostly single bcc phase with nanoscale grain size of 10 to 20 nm has been found to form by annealing amorphous Fe-Zr-B, Fe-Hf-B and Fe-M-B-Cu (M = Ti, Zr, Hf, Nb and Ta) alloys. It has further been clarified that the newly developed nanocrystalline bcc alloys exhibit high permeability (μ_e) combined with high saturation magnetization (B_s). Subsequently, the possible application potentials of the bcc alloys were investigated. The core loss is as small as 66 mW/kg at 1 T and 50 Hz for a nanocrystalline bcc Fe₈₆Zr₇B₆Cu₁ alloy obtained by annealing for 3.6 ks at 873 K. This value is 45 and 95 percent smaller than those for amorphous Fe₈₆Si₉B₁₃ alloy and Fe-3.5 percent Si alloy, respectively, which are presently in use as core materials in electric power transformers. The frequency dependence of the core loss for the bcc alloy at 0.2 T is almost the same as that for an amorphous Co_70.5Fe_4.5Si₁₀B₁₅ alloy with zero magnetostriction. In the frequency range of 10 to 300 kHz, the core loss for the bcc alloy is slightly smaller than the Co base amorphous which has been used as core material in high-frequency transformers. Furthermore, the core losses of the nanocrystalline Fe₈₆Zr₇B₆Cu₁ alloy also were found to have high stability against thermal aging. Thus, nanocrystalline bcc Fe-Zr-B-Cu alloys with the advantages of high B_s, high μ_e, and low core loss is expected to be used as a core material in various transformers.     

Reduction of nitrous oxide emission from pig manure composting by addition of nitrite-oxidizing bacteria

Nitrous oxide (N2O) is emitted from pig manure composting, and the emission correlates with nitrite (NO2-) accumulation in the composting material. In the present study, we added nitrite-oxidizing bacteria (NOB)to inhibit NO2- accumulation and evaluated its effect on N2O emission in a laboratory-scale composting experiment. Mature pig manure compost (MPMC) containing NOB at 10(6) MPN g(-1) WM or cultured MPMC (cul-MPMC) NOB at 10(11) MPN g(-1) WM was added after the thermophilic phase of composting. The addition of these materials prevented NO2- accumulation, promoting oxidation to nitrate (NO3-), whereas the accumulation of NO2- occurred in the material to which NOB was not added as the result of the delayed growth of indigenous NOB compared with that of ammonia-oxidizing bacteria (AOB). The pattern of NO2- in the material agreed with that of N2O emission; therefore, N2O emission ceased rapidly when NOB was added. Emission rates of N2O were 88.5 (no addition), 17.5 (MPMC addition), and 20.2 (cul-MPMC addition) g N-N2O kg(-1) TNinitial, respectively. Improving composition of nitrifying communities for complete nitrification promotion would be useful to establish a composting method with low N2O emission.     

Analysis of Human Oral Mucosa Ex Vivo for Fatty Acid Compositions Using Fourier-transform Infrared Spectroscopy

The purpose of this research was to develop an infrared spectroscopic technique (Fourier transform infrared spectroscopy with attenuated total reflectance system; FTIR-ATR) for non-invasive measurement of saturated and unsaturated fatty acid compositions in human oral mucosa obtained from three nationalities; Iranian, Vietnamese, and Indonesian. The histogram patterns of fatty acid compositions for three nationalities suggest that the pattern of unsaturated fatty acids were quite different, although the distribution profiles of fatty acid to lipid ratios in FTIR-ATR has a similar normal pattern with small difference in skewness and mode. The second derivative infrared spectra of the mucosal tissues in the wavenumber regions from 1,600 to 1,760 cm⁻¹ and 2,800 to 3,050 cm⁻¹ were analyzed with partial least squares (PLS) multivariate regression analysis method. With this analysis method we compared predicted values with the measured values of ten categorized fatty acid compositions, i.e., a(saturated C17 or lower), b(C16:1 + C17:1), c(C18:0), d(C18:1), e(C18:2), f(saturated C20 or longer), g(C20:3 + C20:4), h(C22:1 + C24:1), i(C22:6), j(γC18:3). Almost all fatty acid compositions of oral mucosa were well predicted with differences between predicted and measured values within ±5% of total, however, errors were relatively larger in minor components such as C22:6 than major components.     

Studies on possibility for alleviation of lifestyle diseases by low-dose irradiation or radon inhalation

Our previous studies showed the possibility that activation of the antioxidative function alleviates various oxidative damages, which are related to lifestyle diseases. Results showed that, low-dose X-ray irradiation activated superoxide dismutase and inhibits oedema following ischaemia-reperfusion. To alleviate ischaemia-reperfusion injury with transplantation, the changes of the antioxidative function in liver graft using low-dose X-ray irradiation immediately after exenteration were examined. Results showed that liver grafts activate the antioxidative function as a result of irradiation. In addition, radon inhalation enhances the antioxidative function in some organs, and alleviates alcohol-induced oxidative damage of mouse liver. Moreover, in order to determine the most effective condition of radon inhalation, mice inhaled radon before or after carbon tetrachloride (CCl(4)) administration. Results showed that radon inhalation alleviates CCl(4)-induced hepatopathy, especially prior inhalation. It is highly possible that adequate activation of antioxidative functions induced by low-dose irradiation can contribute to preventing or reducing oxidative damages, which are related to lifestyle diseases.