High-resolution inventory of Japanese anthropogenic mercury emissions

Heavy metals like mercury that are emitted into the environment remain there indefinitely, posing a long-term threat to both the environment and human health. Elemental mercury is volatile and is in gaseous form, and because of the long residence time, transported over long distances. Comprehensive control of mercury emissions therefore remains an important international issue. The crucial steps for designing effective approaches for such control include the quantification of mercury emissions by sources and the identification of geographical characteristics of the emissions. In this study a detailed, high-resolution inventory of Japanese mercury emissions in 2005 was developed to improve understanding of their geographical distribution. Proceeding from a national emissions inventory per source category, emissions were spatially allocated with increasing geographical resolution in a stepwise procedure using statistics from geographic information resources, yielding mercury emissions per prefecture, per municipality and per grid cell of approximately 1 × 1 km. The five prefectures with the highest emissions were Fukuoka, Yamaguchi, Hyogo, Oita, and Hokkaido, accounting for 35.2% of all emissions. In each prefecture a small number of municipalities account for a major share of emissions. Distribution by grid cell is characterized by a concentration of 50% of all emissions in a mere 32 of the 255?954 grid cells over which emissions are distributed in this study. It was also quantitatively confirmed that use of larger grid cells leads to greater uncertainty in emissions distribution. Problems with data collection are clarified and measures to improve the accuracy of future estimation are proposed.     

Development of minimally invasive medical tools using laser processing on cylindrical substrates

This paper reports micro‐fabrication techniques using laser processing on cylindrical substrates for the realization of high‐performance multifunctional minimally invasive medical tools of small size. A spring‐shaped shape memory alloy (SMA) micro‐coil with a square cross‐section has been fabricated by spiral cutting of a Ti‐Ni SMA tube with a femtosecond laser. A small‐diameter active bending catheter actuated by a hydraulic suction mechanism for intravascular minimally invasive diagnostics and therapy has also been developed. The catheter is made of Ti‐Ni superelastic alloy (SEA), which is processed by laser micromachining, and a silicone rubber tube that covers the outside of the SEA tube. The active catheter is effective for insertion into branches of blood vessels that diverge at acute angles where it is difficult to proceed. Multilayer metallization and patterning have been performed on glass tubes with 2‐ and 3‐mm external diameters using maskless lithography techniques with a laser exposure system. Using the laser soldering technique, integrated circuit parts have been mounted on a multilayer circuit patterned on a glass tube. These fabrication techniques will be effective for the realization of high‐performance multifunctional catheters, endoscopic tools, and implanted small capsules. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(1): 65–74, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21030     

Effects of an agonist, allosteric modulator, and antagonist on guanosine-gamma-[35S]thiotriphosphate binding to liposomes with varying muscarinic receptor/Go protein stoichiometry

We investigated whether alcuronium, an allosteric modulator of muscarinic acetylcholine receptors, can induce receptor-mediated activation of Go proteins in liposomal membranes incorporating purified M2 receptors and Go proteins and whether its action is affected by the receptor/Go protein (R/Go) ratio. The binding of guanosine-gamma-[35S]thiotriphosphate ([35S]GTPgammaS) served as the indicator of G protein activation. It was stimulated by empty receptors at high receptor densities, and the dose-response curve was shifted to the left by the agonist carbachol and to the right by the antagonist atropine. At an R/Go ratio of 300:100, the rate of [35S]GTPgammaS binding was the same in the presence or absence of 0. 1 mM carbachol. Alcuronium increased the binding of [35S]GTPgammaS at R/Go ratios of <3:100 and diminished it at R/Go ratios of >10:100, similar to previous observations on intact cells expressing muscarinic receptors at different densities. The apparent biphasicity of alcuronium action indicates that the allosteric modulator has at least two effects on muscarinic receptor/G protein interaction but its mechanistic basis is unclear. The "active state" of muscarinic receptors induced by alcuronium probably is different from that induced by carbachol. Changes in the densities of receptors and Go proteins had little effect on the kinetics of [35S]GTPgammaS binding and on receptor affinity for carbachol, provided the R/Go ratio was kept constant. This suggests that the receptors and G proteins are located in microdomains in which their concentrations remain constant, despite variations in the amounts of lipidic membranes in the system.     

Experimental determination of the energy dependence of defect production

A knowledge of primary damage production as a function of recoil energy is essential for predicting defect production in radiation environments of practical interest. The damage function $\text{ν(T)}$, i.e., the number of Frenkel pairs as a function of recoil energy, is determined for Cu from electron and ion damage-rate measurements. $\text{ν(T)}$ shows a plateau at $\text{ν = 0.54}$ which extends up to ~ $\text{7T}{}_{\mathrm{d}}{}^{\min }$. Therefore, simple damage models, such as the modified Kinchin-Pease expression, are strongly deficient, not only at high recoil energies where stimulated recombination in cascades reduces defect production, but also in the single displacement regime. As a consequence, no simple relation between $\text{T}{}_{\mathrm{d}}{}^{\min }$ and $\text{T}{}_{\mathrm{d}}{}^{\mathrm{av}}$ is expected to exist. A procedure is suggested which uses anisotropy measurements in combination with polycrystal electron and ion irradiations to construct absolute damage functions in metals.     

Effect of swimming training on antioxidant enzymes in kidney of young and old mice

The current study was undertaken to investigate the effect of swimming training on the antioxidant enzyme system in kidney of young and old mice. Both young and old mice, aged 2 and 26 months old, respectively, were divided into the sedentary and swimming-trained groups. The trained mice underwent a 6-week swimming program (1 h/day, 5 days/week) in water at 35-36 degrees C. Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity was significantly decreased with aging but was not influenced by swimming training, such changes being similar to those noted for catalase activity rather than for glutathione peroxidase activity. After swimming training Mn-SOD activity increased significantly only in old mice but was unaffected by aging. Although neither aging nor swimming training had overt effect on the expression of Cu,Zn-SOD mRNA, the immunoreactive Cu,Zn-SOD content in young mice decreased significantly after the training. Meanwhile, Mn-SOD mRNA expression in old mice was reduced by half after swimming training, accompanied by a significant decrease in its immunoreactive content; unexpectedly, however, Mn-SOD content in young mice did not parallel its mRNA expression. These findings suggest that the antioxidant enzyme system in mouse kidney trends to be down-regulated with aging, and that swimming training fails to attenuate such reduced levels of the antioxidant enzymes.     

Hydrolysis of mercerized cotton fibers due to cellulase treatment

Cotton fibers mercerized under the relaxed state were hydrolyzed with crude cellulase. The mercerization treatment examined included ammonia treatment, sodium hydroxide treatment, and two combined treatments using ammonia and sodium hydroxide. Crystalline regions of the mercerized fibers were hydrolyzed in the first step of hydrolysis. In this step, ammonia treatment decreased the crystallite size to a great extent due to the hydrolysis of the cellulose III crystalline phase. Cellulase treatment rendered the crystallite surface highly accessible to water molecules. The crystalline phase was closely related to water sorption of cellulase‐treated fibers. The sequence of treatment had an influence on the fiber structure in the case of the combined mercerization treatment with ammonia and sodium hydroxide. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 364–370, 2000