Right atrial contractile performance in patients with myocardial infarction

To evaluate right atrial (RA) contractile performance in patients with myocardial infarction, we validated a cineangiographic method of RA volume measurement, and investigated RA volume change in 'normal' individuals and patients with a previous myocardial infarction. Sixteen silicone rubber RA casts made from human cadavers were filmed in the postero-anterior and left lateral projections. The cast volumes calculated following Simpson's rule were in good agreement with those measured by water replacement (r = 0.992, P < 0.01). At cardiac catheterization, biplane RA cineangiography was performed in 19 'normal' individuals (N group), in 14 patients with a previous antero-septal infarction (AMI group) and in seven patients with a previous inferior infarction (IMI group). The RA volume-time curve was constructed at 20-40 ms intervals for one cardiac cycle. RA volume at the beginning of the atrial contraction (RAVd), which was defined as the 'preload' of the RA, tended to be larger in both the AMI and IMI groups compared with 'normal' individuals. The RA ejection volume was significantly larger in both the AMI (18.4 +/- 2.1 ml.m-2, P < 0.01) and IMI groups (19.4 +/- 2.8, P < 0.01) than in the N group (14.5 +/- 1.9), even for a comparable level of RAVd (range from 26 to 36 ml.m-2) (18.6 +/- 2.1, P < 0.01, 18.2 +/- 2.0, P < 0.01, 14.7 +/- 1.9, respectively). These results suggest that RA contraction increases in patients with myocardial infarction by increasing both the 'preload' and 'contractility' of the RA.     

Experimental demonstration of soliton data transmission over unlimited distances with soliton control in time and frequency domains

A 2/sup 9/-1 pseudorandom-binary-sequence soliton signal has been transmitted experimentally over one million km for the first time with no degradation in the bit error rates. The synchronous modulator was driven by a timing clock signal extracted from the transmitting data signal. These results mean that it is possible to send soliton data signals over unlimited distances through the use of soliton control in the time and frequency domains.<>     

Design of new catalysts for ecological high-quality transportation fuels by combinatorial computational chemistry and tight-binding quantum chemical molecular dynamics approaches

Recently, we introduced a concept of combinatorial chemistry to computational chemistry and proposed a new method called “combinatorial computational chemistry”, which enables us to perform a theoretical high-throughput screening of catalysts. In the present paper, we reviewed our recent application of our combinatorial computational chemistry approach to the design of new catalysts for high-quality transportation fuels. By using our combinatorial computational chemistry techniques, we succeeded to predict new catalysts for methanol synthesis and Fischer–Tropsch synthesis. Moreover, we have succeeded in the development of chemical reaction dynamics simulator based on our original tight-binding quantum chemical molecular dynamics method. This program realizes more than 5000 times acceleration compared to the regular first-principles molecular dynamics method. Electronic- and atomic-level information on the catalytic reaction dynamics at reaction temperatures significantly contributes the catalyst design and development. Hence, we also summarized our recent applications of the above quantum chemical molecular dynamics method to the clarification of the methanol synthesis dynamics in this review.     

Fractionation and enrichment of CLA isomers by selective esterification with Candida rugosa lipase

A commercial product of CLA contains almost equal amounts of cis-9,trans-11 (c9,t11)-CLA and trans-10,cis-12 (t10,c12)-CLA. We attempted to enrich the two isomers by a two-step selective esterification using Candida rugosa lipase that acted on c9,t11-CLA more strongly than on t10,c12-CLA. An FFA mixture containing CLA isomers was esterified with an equimolar amount of lauryl alcohol in a mixture of 20% water and the lipase. When the esterification of total FA reached 50%, two isomers were fractionated in a good yield: t10,c12-CLA was enriched in FFA, and c9,t11-CLA was recovered in lauryl esters. The FFA were esterified again to enrich t10,c12-CLA. At 27.3% esterification of total FA, the t10,c12-CLA content in FFA increased to 64.8 wt% with 89.3% recovery: The ratio of the content of t10,c12-CLA to that of two isomers was 95.9%. Lauryl esters obtained by the single esterification were employed for enrichment of c9,t11-CLA. After the esters were hydrolyzed, the resulting FFA were esterified again with lauryl alcohol. At 62.0% esterification of total FA, the c9,t11-CLA content in lauryl esters increased to 73.3 wt% with 79.4% recovery: The ratio of the content of c9,t11-CLA to that of two isomers was 95.6%. In a 600-g-scale purification, molecular distillation was effective in separating the reaction mixture into lauryl alcohol, FFA, and lauryl ester fractions.     

Anionic polymerization of styrene in 2-methyltetrahydrofuran: temperature dependence of the field effect

Kinetics of living anionic polymerizations of styrene was investigated for lithium, sodium, and potassium salts in 2-methyltetrahydrofuran at 35, 25, 0, and ?70°C in the presence and absence of a high intensity electric field. At 35 and 25°C, a field acceleration effect was observed whereas no effect was found at 0 and ?70°C. The propagation rate constant of ion pairs was almost independent of gegen ions and their temperature dependence was smaller than that of free anions. The free ions seem to be more strongly solvated as the temperature decreases.     

Topology optimization for fluid–thermal interaction problems under constant input power

This paper deals with density-based topology optimization considering fluid and thermal interactions, in which the Navier–Stokes and heat transport equations are coupled. We particularly focus on designing heat exchangers. In the engineering context, heat exchangers are designed while considering a certain amount of input power. Therefore it is important to maximize the performance of a heat exchanger under a constant input power. In this paper we propose a way to control the input power by introducing an extra integral equation. To be more precise, in the fluid analysis, the inlet pressure is determined by solving the extra integral equation together with the Navier–Stokes equation. By doing this we can keep the inlet power constant even when the flow channels are changed in the optimization process. Consequently, the system of equations of the fluid field takes an integrodifferential form. On the other hand, in the heat transport analysis, a single governing equation is defined for simultaneously modeling both the solid and fluid parts. The design variable is a fluid fraction whose distribution represents the topology of the solid and fluid domains. When designing heat exchangers, two different heat conditions are considered in the formulation of the optimization problems, namely temperature-dependent and temperature-independent heat sources. Through the numerical examples for designing flow channels in a heat exchanger, it is shown that distinct topologies can be obtained according to the input power and the heat source conditions.     

Ultra light-weight and high-resolution X-ray mirrors using DRIE and X-ray LIGA techniques for space X-ray telescopes

We are developing novel ultra light-weight and high-resolution X-ray micro pore optics for space X-ray telescopes. In our method, curvilinear micro pore structures are firstly fabricated by silicon deep reactive ion etching (DRIE) or X-ray LIGA processes. Secondly, side walls of the micro structures are smoothed by magnetic field assisted finishing and/or hydrogen annealing techniques for high reflectivity mirrors. Thirdly, to focus parallel X-ray lights from astronomical objects, these structures are elastically or plastically bent into a spherical shape. Fourthly, the bent structures are stacked to form a multi-stage X-ray telescope. In this paper, we report on fabrication and X-ray reflection tests of silicon and nickel X-ray mirrors using the DRIE and LIGA processes, respectively. For the first time, X-ray reflections were confirmed on both of the mirrors. Estimated rms roughnesses were 5 nm and 3 nm for the silicon and nickel mirrors, respectively.