In a previous study, the AC loss characteristics of each layer of a high-temperature superconducting (HTS) AC cable were experimentally investigated 1-3. Based on these data, we modeled the AC loss ...in a superconducting cable by considering the maxi-mum and minimum values of the loss. A comparison between this model and the experimental data showed good agreement. Hence, it is possible to estimate AC loss under electromagnetic conditions in a high-temperature superconducting cable. This model makes it possible to determine the losses of each layer in the superconducting cable and to design the minimum AC loss load of the superconducting cable. This model estimates the AC losses of a three-layer twisted HTS cable.
In this study, we developed a cellular automaton (CA) model to simulate the multiphase microstructural evolution of the solidification of Fe-C binary peritectic alloys. Three phases were considered ...in the model: δ, γ, and liquid (L). To simulate microstructures formed by the peritectic transformation, moving interfaces at δ-γ, δ-L, and γ-L transformations were introduced for diffusion-controlled growth. The coarsening growth of γ grains after solidification of peritectic alloys was modelled using the CA method. Numerical simulations of multi-phase microstructure evolution for hyper-peritectic and hypo-peritectic alloys were performed in two and three dimensions. In these simulations, the nuclei of γ phases were formed at the δ/L interface below the peritectic temperature. After nucleation of the γ phase in hyper-peritectic alloys, the δ phase in the calculation domain disappeared before γ solidification was completed. Conversely, in hypo-peritectic alloys, the L phase disappeared before the δ-γ transformation was complete. Moreover, the coarsening of γ grains occurred for both alloys after the end of the peritectic transformation. These outcomes agree with the fact that the phase transformation of alloys involves the solidification of peritectic alloys. Thus, we confirmed that the proposed model was a valid approach to simulating multi-phase microstructures formed by the solidification of peritectic alloys.
In the rat, some findings have been taken to suggest the existence of monosynaptic corticomotoneuronal (CM) connections. Because this connection is believed to be largely responsible for the ability ...to make independent digit movements in primates and man, it has been inferred that the monosynaptic CM connection in the rat is likewise important for skilled prehension. Comparison of intra- and extracellular recordings from forelimb motoneurons in anesthetized rats, revealed no monosynaptic CM excitatory postsynaptic potentials (EPSPs). The fastest descending excitation in forelimb motoneurons was disynaptically mediated via a corticoreticulospinal pathway and slowly conducted excitation via corticospinal fibers and segmental interneurons. The findings stress the importance of di- and trisynaptic excitatory corticofugal pathways to forelimb motoneurons in the control of skillful digit movements.
Conjugated fatty acids have attracted much attention as a novel type of biologically beneficial functional lipid. Some isomers of conjugated linoleic acid (CLA) reduce carcinogenesis, ...atherosclerosis, and body fat. Considering the use of CLA for medicinal and nutraceutical purposes, a safe isomer-selective process is required. The introduction of biological reactions for CLA production could be an answer. We screened microbial reactions useful for CLA production, and found several unique reactions in lactic acid bacteria. Lactic acid bacteria produced CLA from linoleic acid. The produced CLA comprised a mixture of
cis-9,
trans-11-octadecadienoic acid (18:2) and
trans-9,
trans-11-18:2.
Lactobacillus plantarum AKU 1009a was selected as a potential CLA producer. Using washed cells of
L. plantarum AKU 1009a as a catalyst, CLA production from linoleic acid reached 40 mg/ml under the optimized conditions. The CLA-producing reaction was found to consist of two successive reactions,
i.e., hydration of linoleic acid to 10-hydroxy-12-octadecenoic acid and dehydrating isomerization of the hydroxy fatty acid to CLA. On the basis of these results, the transformation of hydroxy fatty acids by lactic acid bacteria was investigated. Lactic acid bacteria transformed ricinoleic acid (12-hydroxy-
cis-9-octadecenoic acid) to CLA (a mixture of
cis-9,
trans-11-18:2 and
trans-9,
trans-11-18:2). Castor oil, which is rich in the triacylglycerol form of ricinoleic acid, was also found to act as a substrate for CLA production by lactic acid bacteria with the aid of lipase-catalyzed triacylglycerol hydrolysis.
L. plantarum AKU 1009a produced conjugated trienoic fatty acids from α- and γ-linolenic acid. The trienoic fatty acids produced from α-linolenic acid were identified as
cis-9,
trans-11,
cis-15-octadecatrienoic acid (18:3) and
trans-9,
trans-11,
cis-15-18:3. Those produced from γ-linolenic were
cis-6,
cis-9,
trans-11-18:3 and
cis-6,
trans-9,
trans-11-18:3. The conjugated trienoic fatty acids produced from α- and γ-linolenic acid were further saturated by
L. plantarum AKU 1009a to
trans-10,
cis-15-18:2 and
cis-6,
trans-10-18:2, respectively.
Aims
Purine‐degrading enzymes are favourable as medications and diagnostic tools for hyperuricemia. This study aimed to characterize enzymes isolated from micro‐organisms, which may be useful for ...developing a new prophylaxis for hyperuricemia.
Methods and Results
Cellulosimicrobium funkei A153 was found to be a good catalyst for hypoxanthine degradation and could oxidize hypoxanthine to xanthine and further to uric acid. The enzyme catalysing this oxidation was purified, and its partial amino acid sequences were examined. Based on this information and genome sequencing results, this xanthine dehydrogenase family protein was cloned and expressed in Rhodococcus erythropolis L88. The recombinant enzyme with a His‐tag was characterized. The enzyme was a xanthine oxidase as it could utilize molecular oxygen as an electron acceptor. It was stable under 50°C and exhibited maximum activity at pH 7·0. The kcat, Km and kcat/Km values for xanthine were 1·4 s−1, 0·22 mmol l−1 and 6·4 s−1 mmol−1 l, respectively.
Conclusions
Xanthine oxidase is favourable for hyperuricemia medication because it oxidizes hypoxanthine, an easily adsorbed purine, to xanthine and further to uric acid, which are hardly adsorbed purines.
Significance and Impact of the Study
The enzyme is useful for decreasing serum uric acid levels via conversion of easily absorbed purines to hardly absorbed purines in the intestine. Enzymes from micro‐organisms may be used as a novel prophylaxis for hyperuricemia.
The magnetic flux capturing of MgB2 bulk magnets made by spark plasma sintering process has been precisely investigated to clarify the mechanism of flux motions during the pulse-field magnetization ...processes. The field trapping ratio BT/BP was evaluated as a key parameter of field trapping ability which strongly relates to the heat generation due to the rapid flux motion in the samples. The time dependence of magnetic flux density revealed the actual flux motion which penetrated the samples. The trapped fields BT and field trapping ratios BT/BP of various samples were classified into three regions of 'no flux flow', 'fast flux flow' and 'flux jump' according to the generation of heat and its propagation. A flux jump was observed late at 280 ms from the beginning of PFM process, while the field penetration BP showed its peak at 10 ms. Considering the heat propagation speed, the long-delayed flux jump should be attributed to the macroscopic barriers against the heat propagation to the surface centre of bulk magnet.
Aims This study aims to produce hydroxy fatty acids efficiently. Methods and Results Escherichia coli overexpressing linoleic acid Delta9 hydratase from Lactobacillus plantarum AKU 1009a was employed ...to produce hydroxy fatty acids with industrial potential. We found that 280 g l-1 of linoleic acid (1 mol l-1) was converted into (S)-10-hydoxy-cis-12-octadecenoic acid (HYA) with a high conversion rate of 98% (mol/mol) and more than 99·9% enantiomeric excess (e.e.) by recombinant E. coli cells in the presence of FAD and NADH. In the same way, many kinds of C18 unsaturated fatty acids with Delta9 carbon double bond (280 g l-1) were converted into corresponding 10-hydroxy fatty acids with the conversion rates over 95% (mol/mol). We also produced HYA at a high rate of accumulation (289 g l-1) with a high yield (97 mol%) in a reaction mixture that contained glucose instead of NADH. Conclusions We developed a process for producing several types of hydroxy fatty acids with high accumulation rates and high yields. Significance and Impact of the Study Hydroxy fatty acids are important materials for the chemical, food, cosmetic and pharmaceutical industries, and thus they have recently attracted much interest in a variety of research fields. However, the mass production of hydroxy fatty acids has been limited. This method of hydroxy fatty acids production will facilitate the widespread application of hydroxy fatty acids in various industries.
Aims
This study aims to produce hydroxy fatty acids efficiently.
Methods and Results
Escherichia coli overexpressing linoleic acid Δ9 hydratase from Lactobacillus plantarum AKU 1009a was employed to ...produce hydroxy fatty acids with industrial potential. We found that 280 g l−1 of linoleic acid (1 mol l−1) was converted into (S)‐10‐hydoxy‐cis‐12‐octadecenoic acid (HYA) with a high conversion rate of 98% (mol/mol) and more than 99·9% enantiomeric excess (e.e.) by recombinant E. coli cells in the presence of FAD and NADH. In the same way, many kinds of C18 unsaturated fatty acids with Δ9 carbon double bond (280 g l−1) were converted into corresponding 10‐hydroxy fatty acids with the conversion rates over 95% (mol/mol). We also produced HYA at a high rate of accumulation (289 g l−1) with a high yield (97 mol%) in a reaction mixture that contained glucose instead of NADH.
Conclusions
We developed a process for producing several types of hydroxy fatty acids with high accumulation rates and high yields.
Significance and Impact of the Study
Hydroxy fatty acids are important materials for the chemical, food, cosmetic and pharmaceutical industries, and thus they have recently attracted much interest in a variety of research fields. However, the mass production of hydroxy fatty acids has been limited. This method of hydroxy fatty acids production will facilitate the widespread application of hydroxy fatty acids in various industries.
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