Effect of polyethyleneglycol on polymerization of methyl methacrylate initiated by sodium salt-type macromolecular electrolytes

Summary The effects of polyethyleneglycol (PEG) on the radical polymerizations of methyl methacrylate initiated with the aqueous solutions of such macromolecular electrolytes as sodium polyphenolate and sodium polycarboxylate were studied. PEG was found to promote the polymerizations initiated by such sodium salt-type's macromolecular electrolytes.Vinyl Polymerization. 415.     

Evolutionary robot controllers with competitive and cooperative neural networks

This article describes a new approach for control systems for an autonomous mobile robot by using sandwiches of two different types of neural network. One is a neural network with competition and cooperation, and is used for recognizing sensor information where synaptic coupling are fixed. The second is a neural network with adaptive synaptic couplings corresponding to a genotype in a creature, and used for self-learning for the wheel controls. In a computer simulation model, we were successful in obtaining four types of robot with good performance when going along a wall. The model also showed robustness in a real environment. This work was presented, in part, at the Sixth International Symposium on Artificial Life and Robotics, Tokyo Japan, January 15–17, 2001     

Semi-quantitative approach to estimating GFR by magnetic resonance imaging

Objective: The purpose of this study was to compare a semi-quantitative approach to estimating glomerular filtration rate (GFR) by magnetic resonance imaging with radionuclide calculation of GFR, and to investigate whether spin echo or gradient echo is more suitable for estimating GFR.Methods and patients: Fourteen kidneys of seven patients (GFR ranging from 26 to 57 ml/min) were studied. Spin echo and gradient echo sequences interleaving each other at every excitation were used. After intravenous injection of gadopentetate dimeglumine, serial scans were performed. The signal intensities measured in the regions of interest were converted to time-transverse relaxation rate changes for both spin echo (ΔR2) and gradient echo (ΔR2^*). The areas under the time-ΔR2 and time-ΔR2^* curves were calculated as a semi-quantitative index of GFR for both spin echo and gradient echo images, and the results were compared by GFR measured by radionuclide imaging.Results: The semi-quantitative index of the GFR calculated from spin echo images showed a significant correlation with the GFR measured by radionuclide imaging (r=0.85,P<0.001). On the other hand, the semi-quantitative index of the GFR calculated from gradient echo images showed no such correlation (r=0.46,P=0.10).Conclusion: Spin echo sequences may be more suitable than gradient echo sequences for the evaluation of GFR.     

Utility of spectral vegetation index for estimation of gross CO2 flux under varied sky conditions

To estimate the gross CO₂ flux (F_CO2) of deciduous coniferous forest from canopy spectral reflectance, we introduced spectral vegetation indices (VIs) into a light use efficiency (LUE) model of mature Japanese larch (Larix kaempferi) forest. We measured the eddy covariance CO₂ flux and spectral reflectance of larch canopy at half-hourly intervals during one growing season, and investigated the relationships between the parameters of the LUE model (FAPAR, ?) and 3 types of VIs (NDVI, PRI, EVI) in both clear sky and cloudy conditions.FAPAR (fraction of absorbed photosynthetically active radiation) had a positive linear relationship with both NDVI (normalized difference vegetation index) and EVI (enhanced vegetation index), and the sky condition had little effect on the relationships. The relative RMSE (root mean square error) of the APAR (absorbed photosynthetically active radiation) based on the incoming PAR and estimated FAPAR from a linear function of NDVI was less than 10.5%, irrespective of sky condition.Half-hourly values of ? (conversion efficiency of absorbed energy) showed both seasonal variation related to leaf phenology and short-term variation related to light intensity due to varied sun position and sky condition. Both EVI and PRI (photochemical reflectance index) were significantly correlated with ?. EVI showed a positive linear relationship with ? as a result of their similar seasonal variation. However, since EVI did not detect short-term variation of ?, their relationship differed among sky conditions. On the other hand, although PRI could trace the short-term variation of ? in green needles, the relationship became non-linear due to drastic reduction of PRI in the senescent needles.EVI/(PRI/PRI_min), a combined index based on a 6-day moving minimum value of PRI (PRI_min), showed a linear relationship with half-hourly values of ? throughout the seasons irrespective of sky condition. This index allow us to estimate ? in all sky conditions with a smaller error (rRMSE = 35.2%) than using EVI or PRI alone (38.7%-48.7%). Consequently, this combined index-derived ? and NDVI-based FAPAR gave a low estimation error of F_CO2 (rRMSE = 36.4%, RMSE = 8.3 μmol m^− 2 s^− 1). Although there are still various issues to resolve, including adaptive limit and combination of vegetation index type, we conclude that the combination of PRI and EVI increased the accuracy of estimation of CO₂ uptake in deciduous forest even though sky conditions varied.     

Peroxisomal metabolism is regulated by an oxygen-recognition system through organelle crosstalk between the mitochondria and peroxisomes

In the present study using Pichia methanolica, it was found that expressions of methanol-metabolic enzymes were strictly regulated by the presence of oxygen, and that induction of alcohol oxidase (AOD) isozymes was completely dependent on oxygen concentrations. A proportion of AOD-isozyme species responded to oxygen conditions, e.g. in a low oxygen condition, Mod1p was dominant, but with an increase in the oxygen concentration, the ratio of Mod2p increased. The K(m) value of Mod1p for oxygen was ca. one-seventh lower than that of Mod2p (0.47 and 3.51 mM, respectively). This shows that Mod1p is suitable at low oxygen concentrations and Mod2p at high oxygen concentrations. Also, zymogram changes for AOD isozymes were observed by inhibition of respiratory chain activity. These indicated that P. methanolica has the ability to recognize oxygen conditions and the respiratory chain should participate in the sensor for available oxygen. These facts indicate that there is organelle crosstalk between mitochondria and peroxisomes through nucleus gene regulation in order to control the consumption balance of available oxygen between the mitochondrial respiratory chain and peroxisomal AODs.     

Label-free DNA biosensor based on localized surface plasmon resonance coupled with interferometry

In this report, we developed a new optical biosensor in connection with a gold-deposited porous anodic alumina (PAA) layer chip. In our sensor, we observed that the gold deposition onto the chip surface formed a "caplike" layer on the top of the oxide nanostructures in an orderly fashion, so we called this new surface formation a "gold-capped oxide nanostructure". As a result of its interferometric and localized surface plasmon resonance properties, the relative reflected intensity (RRI) at surface of the chip resulted in an optical pattern that was highly sensitive to the changes in the effective thickness of the biomolecular layer. We demonstrated the method on the detection of picomolar quantities of untagged oligonucleotides and the hybridization with synthetic and PCR-amplified DNA samples. The detection limit of our PAA layer chip was determined as 10 pM synthetic target DNA. The capability of observing both RRI increment and wavelength shift upon biomolecular interactions promises to make our chip widely applicable in various analytical tests.     

Numerical study of fracture propagating through column and brace of Ashiyahama residential building in Kobe earthquake

There are significant unprecedented structural damages at Ashiyahama residential high‐rise steel building complex due to the Hyogo‐ken Nanbu Earthquake (Kobe Earthquake), which occurred on January 17, 1995. This paper is concerned with two issues of steel fracture observed in the mega‐structure that have been attracting the special attention of structural engineers. These are fracture propagating through very thick‐plated steel column and brace, and brittle‐type fracture at column–column welded connections. The cause of the former damage is first examined using numerical computation with recourse to an explicit method of dynamic analysis based on a continuous medium model. By taking account of the complexity of the mega‐structure, and of the limitation of numerical computation, the analysis is carried out in two distinct steps. In the first approach, the global frame is dynamically analysed on the basis of beam element modelling; the second approach calls for an analysis, based on shell element modelling, of a partial frame that is composed of the joint and the adjacent brace, beam and columns. It turns out that the axial breakage is initiated from the brace and propagates through the column. The second issue of the fracture at column–column welded connections is investigated with consideration to energy balance, or the difference in the total energy across the boundary between the two elements connected at the weld. The paper concludes from a practical point of view with recommendations to enhance earthquake‐resistant capability in the structural design. Copyright © 2004 John Wiley & Sons, Ltd.     

On the promotional effect of Sn in Co–Sn/Al2O3 catalyst for NO selective reduction

NO reduction with propylene over Co/Al₂O₃ and Co–Sn/Al₂O₃ catalysts has been investigated. For the Co/Al₂O₃ catalyst, a calcination temperature exceeding 800°C led to a decrease of NO conversion. Calcination of the Co/Al₂O₃ catalyst at 1000°C resulted in the formation of -Al₂O₃ and Co₃O₄. The presence of 20% water vapor showed a significant shift for the maximum NO reduction temperature from 450 to 600°C over Co/Al₂O₃. It has been found that modification of 6 wt% Co/Al₂O₃ with 2 wt% Sn significantly enhanced the catalyst thermal stability and improved the inhibitory effect of water on NO conversion and reaction temperature. The promotional effect of Sn on the catalyst thermal stability was attributed to the suppression of the phase transformation from highly dispersed Co²⁺ species on -Al₂O₃ to -Al₂O₃ and Co₃O₄. The smaller influence of water vapor on NO reduction conversion and temperature over Co–Sn/Al₂O₃, compared to Co/Al₂O₃, was attributed to the dispersion effect of Sn species on Co²⁺ species as well as the involvement of Sn species in NO reduction at a relatively lower temperature. The synergetic effect between the octahedral Co²⁺ species and -alumina plays a significant role in the catalysis of NO selective reduction by C₃H₆.     

TLR4-Mediated Inflammatory Responses Regulate Exercise-Induced Molecular Adaptations in Mouse Skeletal Muscle

Endurance exercise induces various adaptations that yield health benefits; however, the underlying molecular mechanism has not been fully elucidated. Given that it has recently been accepted that inflammatory responses are required for a specific muscle adaptation after exercise, this study investigated whether toll-like receptor (TLR) 4, a pattern recognition receptor that induces proinflammatory cytokines, is responsible for exercise-induced adaptations in mouse skeletal muscle. The TLR4 mutant (TLR4m) and intact TLR4 control mice were each divided into 2 groups (sedentary and voluntary wheel running) and were housed for six weeks. Next, we removed the plantaris muscle and evaluated the expression of cytokines and muscle regulators. Exercise increased cytokine expression in the controls, whereas a smaller increase was observed in the TLR4m mice. Mitochondrial markers and mitochondrial biogenesis inducers, including peroxisome proliferator-activated receptor beta and heat shock protein 72, were increased in the exercised controls, whereas this upregulation was attenuated in the TLR4m mice. In contrast, exercise increased the expression of molecules such as peroxisome proliferator-activated receptor-gamma coactivator 1-alpha and glucose transporter 4 in both the controls and TLR4m mice. Our findings indicate that exercise adaptations such as mitochondrial biogenesis are mediated via TLR4, and that TLR4-mediated inflammatory responses could be involved in the mechanism of adaptation.