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Along with increasing relevance of rare earth (RE) elements in industrial technology, the risk of their environmental release and occupational exposure on human health is of concern. Although many toxicological studies were reported for REs, it is not known how they affect DNA repair. In this study, the effects on DNA repair of all RE ions except radioactive promethium (Pm) were studied. Human lymphoblastoid WTK1cells were irradiated to UV followed by 2h exposure to each RE with and without DNA repair inhibitor cytosine-1β-D- arabinofuranoside (araC), and then single strand breaks (SSBs) were detected by the comet assay. UV-induced pyrimidine dimers are removed by nucleotide excision repair (NER) which consists of recognition of the DNA lesion, excision of a 24–32 nucleotide stretch containing the lesion by dual incision of the damaged DNA strand on both sides, and re-synthesis of the resulting gap by DNA polymerase, and ligation of the nick. SSBs are generated in the incision step of nucleotide excision repair (NER) and disappear in the re-synthesis step of NER. Seven REs, Yb, Lu, Dy, Er, Sc, Pr, and Ce, enhanced comet positive response without araC but not with araC, suggesting that araC is antagonistic to the 7 REs. Since araC inhibits re-synthesis of NER, these seven REs would inhibit the re-synthesis step of NER. Six REs, Tm, Sm, Tb, Gd, Eu, and Y suppressed comet positive responses with and without araC, suggesting that they decreased comet assay detectable SSBs. Therefore, these 6 REs are considered to inhibit the incision step of NER. Only La decreased tail length without araC but increased with araC, suggesting that La increased comet assay detectable SSBs and that only La would enhance the incision step of NER. Neither Nd nor Ho affected tail length with or without araC.

The dry flower buds of Sophora japonica L. are used as a hemostatic agent in traditional Chinese medicine. In the comet assay, aqueous extracts of S. japonica decreased and increased the tail length significantly in cultured human lymphoblastoid WTK1 cells exposed to UV in the absence and presence of DNA repair inhibitors, respectively. The extract did not affect the tail length in methyl methanesulfonate-exposed cells. In the present study, the aqueous extract of the flower buds of S. japonica was separated by repeated column chromatography, yielding four types of flavonoid glycosides. Among them, only rutin, similar to the extract, decreased and increased the tail length significantly in WTK1 cells exposed to UV in the absence and presence of DNA repair inhibitors hydroxyurea (10 mM) and cytosine-1-β-D-arabinofuranoside (1.8 mM), respectively. The genotoxicity-suppressing effect of rutin was further studied using the micronucleus test. Rutin significantly decreased the frequency of micronucleated binucleate cells in UV-exposed WTK1 cells but did not affect this frequency in UV-exposed XPL3KA (Xeroderma pigmentosum group C) cells. These results suggest that the anti-genotoxic potential of rutin is due to an enhanced incision step of global genome repair (GGR) sub-pathways in nucleotide excision repair (NER). Herein, we show that S. japonica exhibits heretofore unknown anti-genotoxic potential against UV by enhancing the incision of GGR sub-pathways in NER, and that its anti-genotoxic component is rutin.

Background Enamel matrix derivative (EMD) is widely used for regeneration therapy in dental clinical situations, but the mechanism of EMD bioactivity remains obscure. To clarify this mechanism, we focused on the formation of connective tissue and blood vessels. The aim of this study was to confirm whether EMD induces the formation of connective tissue and blood vessels by using the diffusion chamber (DC) technique. Materials and methods Individual DCs containing EMD (DC-EMD) or propylene glycol alginate (PGA) were implanted subcutaneously in rat dorsum. At 4 weeks after the implantation, histological analysis of DCs was performed using azan staining. Results DC-EMD induced the formation of much larger amounts of connective tissue containing abundant blood vessels than did DC-PGA. Conclusion The results indicated that EMD can induce the formation of both connective tissue and blood vessels. This bioactivity may contribute to the mechanism whereby EMD induces tissue regeneration.

e in uence of crystallographic structure on the etching rate of copper was studied in 1 mol/dm ammonium peroxodisulfate solution using a scanning probe microscope (SPM), electron back scatter di raction patterns (EBSD), and corrosion potential measurements. e (001), (101), and (111) faces etched at slower rates than the (327) and (425) faces, which have higher Miller indices. e etching rate of the (001) or (101) oriented polycrystalline copper was approximately half that for the oriented polycrystalline copper with higher indices. e polycrystalline copper etched at highly rate showed a relatively noble corrosion potential. It was suggested that the etching rate of polycrystalline copper was controlled by the mean value of the reduction kinetics of the peroxodisulfate ion on each of the grain surfaces.

Capsicum plants harboring the Hk gene (Hk) show resistance to Paprika mild mottle virus (PaMMV) at 32 degrees C but not 24 degrees C. To identify the viral elicitor that activates the Hk-mediated resistance, several chimeric viral genomes were constructed between PaMMV and Tobacco mosaic virus-L. Infection patterns of these chimeric viruses in Hk-harboring plants revealed responsibility of PaMMV replicase genes for activation of the Hk-mediated resistance. The comparison of nucleotide sequence of replicase genes between PaMMV and PaHk1, an Hk-resistance-breaking strain of PaMMV, revealed that the adenine-to-uracil substitution at the nucleotide position 721 causes an amino acid change from threonine to serine at the 241st residue in the methyltransferase domain. Introduction of the A721U mutation into the replicase genes of parental PaMMV overcame the Hk resistance at 32 degrees C. The results indicate that Hk-mediated resistance is induced by PaMMV replicase proteins and that methyltransferase domain has a role in this elicitation.

Inclusion behavior like nucleation, diffusional growth, coagulation and removal in steel refining are complicated process, whereas mathematical simulation makes it possible to describe each behavior in detail. Many works have been performed in respect of the individual mechanism of inclusion behavior. However, the whole behavior is not clearly understood yet, and especially, an experimental evaluation of combined phenomena has not been carried out sufficiently until now. In this study, a cold model experiment of bubble flotation accompanied by coagulation of polystyrene particle in an electrolyte solution has been conducted in an agitated vessel under turbulent flow condition. In addition, an empirical equation of bubble flotation in a turbulent flow has been proposed from observed results of the water model experiment. This empirical equation has been combined with the population balance equation on particle coagulation, and removal rates have been predicted. Furthermore, a correction has been adopted in the population balance equation proposed by Nakaoka et al. Resultantly, a linear coupling model with bubble flotation and coagulation has been verified its applicability to a prediction of time dependence of particle number density and size distributions under various conditions.

Gas injection is generally practiced in refining processes for metallurgy. The expectances for the gas injection involve the homogenization of bath temperature and compositions, and removal of second phase and dissolved impurities from molten metals.It is widely recognized that inclusions in steel cause defects to the products. Therefore, it is important to remove inclusions from liquid steel. Solid inclusions such as alumina and silica are not wetted by the liquid steel and can be removed by attachment to gas bubbles. The attachment and removal by bubble flotation is expected as one of promising techniques on inclusion removal in liquid steel. The aim of the present work is to investigate the effects of some factors such as particle diameter, agitation speed and particle contact angle to removal rate. In this study, water model experiments have been done under turbulent flow condition using a mechanically agitated vessel. It was confirmed that the removal rate of suspended particles in liquid shows first order kinetics until 4 min in the initial stage. Furthermore, it was found that the collision frequency function has decreased with increasing agitation speed and with decreasing contact angle.

かくはん槽内における塩化第二銅溶液による銅のエッチングについて考察した。本エッチング速度は, 物質移動律速であることがわかった。銅とCuClの溶解速度を比較した結果, 塩化第二銅の低濃度領域を除き, CuClの溶解速度は銅の速度の約2倍になった。したがってこのエッチングにおいては, CuClが銅表面に析出し, エッチング速度はCuCl2-の拡散律速と考えた。CuClの溶解度とCuCl2-の拡散係数からCuCl2-の拡散速度を求めたところ, 実測したエッチング速度と一致した。塩化第二銅低濃度領域におけるエッチング速度についてはイオン間の相互作用を考慮した境膜モデルにより見積もることができた。

The newly developed monitor watches the fluidized condition of FBC (Fluidized Bed Combustor), referring to acoustic signals which are collected by heating tubes in the beds and passing to tube acceleration sensors outside the fluidized Beds. The monitor, without any observation hole or special probes, not only detects the bad-fluidized region, which requires proper operations for preventing from agglomeration, but also diagnoses conditions of the boiler equipment. The monitor adopts the joint time-frequency analysis technique to the acoustic signals as well as considers non-Gaussian properties, on decision making procedure, including skewness and excess of parameter distributions which are the resulting characteristics through the analyses on the time-frequency plain. The monitor has been applied to an 350MWe FBC for testing, and validated through one and a half year operation

Experimental and theoretical studies on the initial leaching rate of a spherical pellet of ZnO introduced in H2SO4 and H2SO4-ZnSO4 solution have been conducted to discuss the characteristics of liquid-phase mass transfer for ZnO-H2SO4 solution systems in an agitated vessel. The results obtained are as follows: 1) For the ZnO-H2SO4 systems, the leaching rate is proportional to the 0.6th power of the stirring rate. The leaching rate increases with the concentration of H2SO4 and H+. 2) For the ZnO-H2SO4-ZnSO4 systems, the leaching rate increases with the concentration of ZnSO4. At a high concentration of H+, the rate is independent of the concentration of H+. 3) The leaching process for these systems is controlled by the liquid-phase mass transfer rate. 4) For the ZnO-H2SO4 and ZnO-H2SO4-ZnSO4 systems, the rates calculated by a mass-transfer model based on a film theory that takes into account diffusion and electrical migration are in good agreement with the experimental values at a low concentration of H+. However, the calculated values are not consistent with the experimental values at high concentration. This disagreement might be caused by the effect of chemical reaction at the ZnO surface.

Tobamovirus resistance in Capsicum plants, which is mediated by L genes (L(1), L(2), L(3) or L(4)), is known to be temperature sensitive. However, the L(1a ) gene, a newly identified tobamovirus resistance gene that is mapped to the L locus, confers temperature-insensitive resistance against the tobamovirus P(0) pathotype. To identify the viral elicitor that activates the L(1a )-gene-mediated resistance, several chimeric viral genomes were constructed between tobacco mosaic virus-L (P(0) pathotype), paprika mild mottle virus-J (P(1 )pathotype) and pepper mild mottle virus-J (P(1,2) pathotype). Infection patterns of these chimeric viruses in L(1a )-harboring plants revealed that the L(1a )-gene-mediated resistance was activated by the CP of a particular pathotype of tobamovirus, like other L-gene-mediated resistances, but the L(1a )-gene-mediated resistance differs from those conferred by other L genes in terms of temperature sensitivity.

Recently, integration of LSI and IC has been developed dramatically because of miniaturization of electronics. So, the wet etching of copper foil plays an important role in the ultra-fine processing technology. In order to produce finer circuits efficiently, kinetics on the etching rate of copper foil in aqueous solutions must be clarified under turbulent flow condition.

This paper is to correct a mistake in the authors' previous paper (Nakaoka et al., Progress in Computational Fluid Dynamics, 2008, 8(5), 270-275), which originated in the solution procedure of the population-balance (PB) equation.

In this study, coagulation rates of various particles observed in agitated water were analysed by a mathematical model of turbulent coagulation. This model is based on the Saffman-Turner model of turbulent collision modified by Higashitani to take into account, van der Waals-London force between a pair of particles under collision. The Higashitani model could not account for the retardation of coagulation rate at high concentrations of suspended particles, which was observed in our precious studies. The new model proposed in this study considered the breakup of coagulating particles due to collision with other particles, and the turbulent shear force. Two parameters were introduced in the model; one was the film-thinning time and the other the breakup frequency. By choosing suitable values of the two parameters, the estimated coagulation curves fitted well with the observed curves. In addition, the film-thinning time increased with increasing wettability of particle and the breakup frequency increased with increasing turbulent intensity.