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Lithium-ion batteries (LIBs) are expected to be main power sources of automobiles. Nevertheless, LIBs easily lead to serious incidents because LIBs have high energy density. For application to automobiles, the reliability of LIBs should be guaranteed against various external loads. Especially, static loads and cyclic loads are constantly applied on LIBs because of vibration and thermal stress induced in automobiles, and fatigue damage occurs in electrodes of the LIBs. In this respect, it is important to evaluate mechanical strength and mechanical fatigue property of electrodes, such as tensile strength and S-N curves. This study has proposed a simple evaluation method of the mechanical strength and the fatigue property of electrodes for LIBs by using mechanical models of the electrodes. The actual alignment of particles of active material is random, and mechanical models based on the actual alignment are too complex to derive the main factor of mechanics of the electrodes. The proposed models approximate the alignment of the particles as the body-centered cubic (bcc) and the face-centered cubic (fcc) which are the well-known crystal lattices. In order to verify the proposed method, static tensile tests and bending fatigue tests of negative electrodes for LIBs have been conducted. From the test results, the tensile strength of the negative electrodes estimated by the proposed models agree with the experimental values, and the difference between the bcc model and the fcc model is smaller than the variation of the experimental values. The estimation value of the stress that initiates a crack on the negative electrodes by 1 cycle agrees with the tensile strength. The number of cycles linearly increases in the log scale with the decrease of the stress amplitude, and the stress amplitude at the 106–107 cycles agrees with the half of the tensile strength.

Dimunito/Dwarf1 (DWF1) is an oxidoreductase enzyme that is responsible for the conversion of C28- and C29-Δ24(28)-olefinic sterols to 24-methyl- and 24-ethylcholesterols. Generally, the reaction proceeds in two steps via the Δ24(25) intermediate. In this study, we characterized the ArDWF1 gene from an expression sequence tag library of Ajuga reptans var. atropurpurea hairy roots. The gene was functionally expressed in the yeast T21 strain. The in vivo and in vitro study of the transformed yeast indicated that ArDWF1 catalyzes the conversion of 24-methylenecholesterol to campesterol. A labeling study followed by GC-MS analysis suggested that the reaction proceeded with retention of the C-25 hydrogen. The 25-H retention was established by the incubation of the enzyme with (23,23,25-2H3,28-13C)-24-methylenecholesterol, followed by 13C NMR analysis of the resulting campesterol. Thus, it has been concluded that ArDWF1 directly reduces 24-methylenecholesterol to produce campesterol without passing through a Δ24(25) intermediate. This is the first characterization of such a unique DWF1 enzyme. For comparison purposes, Oryza sativa DWF1 (OsDWF1) was similarly expressed in yeast. An in vivo assay of OsDWF1 supported the generally accepted two-step mechanism because the C-25 hydrogen of 24-methylenecholesterol was eliminated during its conversion to 24-methylcholesterol. As expected, the 24-methylcholesterol produced by OsDWF1 was a mixture of campesterol and dihydrobrassicasterol. Furthermore, the 24-methylcholesterol contained in the Ajuga hairy roots was determined to be solely campesterol through its analysis using chiral GC-MS. Therefore, ArDWF1 has another unique property in that only campesterol is formed by the direct reduction catalyzed by the enzyme.

In our institute, an MR apparatus, MAGNETOM VISION (Siemens) was replaced by ECHELON Vega (HITACHI). Z-score data acquired by MPRAGE (VISION) was compared with those by radio frequency-spoiled steady-state acquisition with rewinded gradient echo (RSSG) and gradient echo inversion recovery (GEIR) (ECHELON). For this study, ten normal volunteers were recruited and their data ware obtained within two months using both apparatuses. In addition, the difference of the contrasts of the images of these apparatuses was compared. There was a significant difference between Z-scores of MPRAGE and RSSG while there was no difference between MPRAGE and GEIR. As for the contrast, data of MPRAGE were similar to those of GEIR. To compare Z-scores acquired with MAGNTOM VISION (Siemens), it seems appropriate to use GEIR in ECHELON Vega.

20-Hydroxyecdysone (20HE), a molting hormone of insects, is also distributed among a variety of plant families. 20HE is thought to play a role in protecting plants from insect herbivores. In insects, biosynthesis of 20HE from cholesterol proceeds via 7-dehydrocholesterol and 3β,14α-dihydroxy-5β-cholest-7-en-6-one (5β-ketodiol), the latter being converted to 20HE through sequential hydroxylation catalyzed by four P450 enzymes, which have been cloned and identified. In contrast, little is known about plant 20HE biosynthesis, and no biosynthetic 20HE gene has been reported thus far. We recently proposed involvement of 3β-hydroxy-5β-cholestan-6-one (5β-ketone) in 20HE biosynthesis in the hairy roots of Ajuga reptans var. atropurpurea (Lamiaceae). In this study, an Ajuga EST library was generated from the hairy roots and P450 genes were deduced from the library. Five genes with a high expression level (CYP71D443, CYP76AH19, CYP76AH20, CYP76AH21 and CYP716D27) were screened for a possible involvement in 20HE biosynthesis. As a result, CYP71D443 was shown to have C-22 hydroxylation activity for the 5β-ketone substrate using a yeast expression system. The hydroxylated product, 22-hydroxy-5β-ketone, had a 22R configuration in agreement with that of 20HE. Furthermore, labeling experiments indicated that (22R)-22-hydroxy-5β-ketone was converted to 20HE in Ajuga hairy roots. Based on the present results, a possible 20HE biosynthetic pathway in Ajuga plants involved CYP71D443 is proposed.

The first total syntheses of acetogenin 3 and its 4S,8R-isomer are described. The key step involves intermolecular metathesis of an α,β-unsaturated ketone carrying a tetrahydropyranyl lactone with a tetrahydrofuran derivative. Compound 3 has spectroscopic and physical data consistent with those of natural montanacin D, suggesting that the absolute configuration of the natural product is as shown in 3.