Mechanism of action of acetyl kidamycin. I. Interaction with DNA

During the period from November 1972 to February 1975, 39 patients received second renal grafts in our institution. The clinical course of the patients was analyzed and compared with 121 patients who received only one graft during the same period. The graft survival either from living related or cadaveric sources was inferior in the second graft group. However, mortality was not increased by re-transplantation. Major differences were noted in the occurrence of hyperacute or accelerated type rejections. There was a high incidence of this type of rejection in the second graft group, especially in the simultaneous retransplant group.     

Site-selective blocking of PCR by a caged nucleotide leading to direct creation of desired sticky ends in the products

In order to terminate the polymerase reaction at a desired position, a caged thymine derivative--4-O-[2-(2-nitrophenyl)propyl]thymine--was incorporated into PCR primers. In the PCR cycles, the elongation of the nascent strand (5'-->3' direction) by polymerase was site-selectively terminated at the 3'-side of T(NPP). Accordingly, predetermined protruding ends were obtained after the removal of the protecting group by short UVA irradiation. Recombinant vectors coding the GFP gene were successfully prepared by direct ligation of these light-assisted cohesive-ending PCR (LACE-PCR) products with scission fragments obtained by use either of restriction enzymes or of artificial restriction DNA cutters and were used for transformation of E. coli.     

Synthesis, thermal stability, and oxygen intake/release characteristics of YBa(Co1−xAlx)4O7+δ

The YBaCo₄O_7+d (Y-114) phase has recently attracted interests as a potential oxygen storage material due to its oxygen intake/release capability at 200-400 °C. Nevertheless, thermal instability of Y-114 has been an obstacle for future applications, since this compound immediately starts to decompose when the sample is heated at 700-800 °C in oxygen-rich atmosphere. Here we demonstrate that Al-for-Co substitution in Y-114 drastically enhances the thermal stability. Substituting only 10 at.% of aluminum for cobalt in Y-114 essentially suppresses the decomposition reaction seen at 700-800 °C, while well retaining its remarkable oxygen intake/release capability at 200-400 °C. It is also revealed that the addition of aluminum effectively reduces the particle size. The Al-substituted Y-114 products exhibit superior oxygen intake/release response to the Al-free products upon switching the atmosphere between O₂ and N₂.     

Thermoelectric Properties of Ca3Co4O9/[Ca2(Co0.65Cu0.35)2O4]0.624CoO2 Composites

Ca₃Co₄O₉ is one of the most promising p-type thermoelectric materials because of its high dimensionless figure of merit ZT. However, polycrystalline Ca₃Co₄O₉ ceramics shows lower ZT value than that for single crystal Ca₃ Co₄O₉ due to its higher electrical resistivity ρ. Mikami et al. have reported that the addition of Ag to Ca₃Co₄O₉ ceramics could successfully reduce ρ and enhance the power factor. On the other hand, Ohtaki et al. reported that a composite structure could be highly effective to reduce κ for ZnO dually doped with Al and Ga. In this work, we tried to enhance the power factor and reduce κ by forming Ca₃Co₄O₉/[Ca₂(Co_0.65Cu_0.35)₂O₄]_0.624CoO₂ composite structure. As a result, the ZT value for Ca₃Co₄O₉/[Ca₂(Co_0.65Cu_0.35)₂O₄]_0.624CoO₂ composites reached 0.164 at 700 °C, which was 40 % higher than the value for Ca₃Co₄O₉.     

Antioxidative activities of tocotrienols on phospholipid liposomes

Antioxidative activity of tocotrienol (Toc3) was studied in the oxidation of dilinoleoylphosphatidylcholine (DLPC) liposomes. The objective was to measure the differences in the antioxidative activities betweenα-Toc3 andα-tocopherol (α-Toc), and betweenγ-Toc3 andγ-Toc. When each antioxidant was added to the already prepared DLPC liposome solution, the antioxidative activity of Toc3 was larger than that of Toc. However, when incorporated into the liposomal membrane, the antioxidative activities of Toc3 and Toc were the same and were intermediate between those of the added Toc3 and Toc. When added to the liposome solution, the consumption of Toc3 during the induction period was larger than that of Toc. When incorporated into the liposomal membrane, the consumptions of Toc3 and Toc were the same and were intermediate between those of the added Toc3 and Toc. These results suggest that the reactions of Toc3 and Toc with phospholipid peroxide within the membrane are inhibited to a different degree depending on the dosing manner of Toc3 and Toc. Namely, the degree of inhibition decreases in the following order: Toc(added)> Toc(incorporated)= Toc3(incorporated)> Toc3(added).     

A solution to combinatorial optimization problems using an accelerated hopfield neural network

Hopfield has shown that the combinatorial optimization problem can be solved on an artificial neural network system by minimizing the quadratic energy function. One of the difficulties in applying the network to actual problems is that the network converges to local minimum solutions very slowly because the sigmoid function is used for an input-output function of the neuron. To overcome this difficulty, this paper proposes an accelerated Hopfield neural network which can control the speed of convergence near the local minima by an acceleration parameter. Computational results for the combinatorial problems with two and twenty-five variables show that: (1) the proposed model converges to the local minima more quickly than the conventional model; (2) that the acceleration of convergence makes the attraction region of each local minimum change and worsens the accuracy of the solution; and (3) that if an initial point is selected around the center of the unit hypercube, the proposed network converges to a local minimum very quickly with high accuracy, and these good properties remain unchanged by the acceleration parameter.     

A method for evaluating the noise temperature of microwave thermalnoise sources by introducing an auxiliary transmission line

A method is proposed to evaluate the noise temperature of a microwave thermal noise source. The noise temperature correction factor due to the transmission line between the termination and the output is expressed in terms of directly measurable parameters. The correction factor is determined by introducing an auxiliary transmission line composed to two lines connected back-to-back, each of which is identical to that of the unknown source     

Preparation and Optical Nonlinear Property of Sol–Gel-Derived Cu─SiO2 Thin Films

Cu-metal-doped glass films having a Cu:Si atomic ratio of 0.05 ± 0.002 were successfully prepared by a sol-gel method using a dipping technique. The appearance of surface plasmon of Cu metal at about 570 nm was observed after heat treatment at or above 700°C. The third-order nonlinear susceptibility (x³) was as high as 5.0 × 10^–8 esu at 570 nm.