Theanine,Antistress Amino Acid in Tea Leaves,Causes Hippocampal Metabolic Changes and Antidepressant Effects in Stress-Loaded Mice

By comprehensively measuring changes in metabolites in the hippocampus of stress-loaded mice, we investigated the reasons for stress vulnerability and the effect of theanine, i.e., an abundant amino acid in tea leaves, on the metabolism. Stress sensitivity was higher in senescence-accelerated mouse prone 10 (SAMP10) mice than in normal ddY mice when these mice were loaded with stress on the basis of territorial consciousness in males. Group housing was used as the low-stress condition reference. Among the statistically altered metabolites, depression-related kynurenine and excitability-related histamine were significantly higher in SAMP10 mice than in ddY mice. In contrast, carnosine, which has antidepressant-like activity, and ornithine, which has antistress effects, were significantly lower in SAMP10 mice than in ddY mice. The ingestion of theanine, an excellent antistress amino acid, modulated the levels of kynurenine, histamine, and carnosine only in the stress-loaded SAMP10 mice and not in the group-housing mice. Depression-like behavior was suppressed in mice that had ingested theanine only under stress loading. Taken together, changes in these metabolites, such as kynurenine, histamine, carnosine, and ornithine, were suggested to be associated with the stress vulnerability and depression-like behavior of stressed SAMP10 mice. It was also shown that theanine action appears in the metabolism of mice only under stress loading.     

Preparation of porous polymer materials using water‐in‐oil gel emulsions as templates

Water‐in‐oil gel emulsions consisting of water and n‐butyl acrylate were successfully prepared using N‐3‐hydroxybutylcarbonyl‐l ‐isoleucylaminooctadecane and sorbitan monooleate (Span 80) as gelator and surfactant, respectively. Stable gel emulsions were formed using aqueous phase fractions (APFs) ranging from 10 to 90 vol%. Creaming, flocculation and coalescence were not observed. Low‐temperature polymerization of the gel emulsions with a redox initiator gave the corresponding low‐density, highly porous poly(n‐butyl acrylate)s (PBAs). The microstructures of the PBAs were observed using scanning electron microscopy. All the porous PBAs comprised numerous spherical structures whose sizes could be controlled by adjusting the gel emulsion APF. The densities and porosities of the porous PBAs decreased and increased, respectively, with increasing APF. The absorption capacities of the porous PBAs in organic solvents were studied. The porous PBAs selectively absorbed kerosene from water instantly and the kerosene could then be recovered by physical compression of the PBAs. Further porous polymers were prepared from gel emulsions containing styrene, methyl methacrylate (MMA) or 2‐ethylhexyl acrylate (EHA) as continuous oil phases. The order of absorption capacity and swelling ratio in kerosene was poly(EHA) > PBA ? poly(MMA). Porous copolymers were also prepared from gel emulsions containing a mixture of EHA and MMA as the oil phase. Their absorption and swelling in liquids could be controlled by changing the ratio of EHA and MMA in the gel emulsions. poly(EHA‐co‐MMA) (6:4) was the best polymer when absorption capacity, swelling ratio and durability were simultaneously considered. © 2018 Society of Chemical Industry     

Triangular cross-section peristaltic conveyor for transporting powders at high speed in printers

Powder-based materials are widely used in various applications such as printing. In printing, low shear force and high-speed conveyance at low temperatures are required to prevent creating defects in materials. In a previous study, we developed a transportation device based on the human intestinal tract that successfully transported highly viscous and solid–liquid fluid mixes and powder material. In this study, we developed a tubular peristaltic conveyor capable of transporting powdered materials in a printer under the aforementioned conditions. The conveyor had a triangular cross-sectional area and a small air chamber to facilitate high-speed peristaltic motion. The performance of the conveyor was confirmed experimentally, and we achieved a conveyance rate of 81.5?g/s.     

Recursive algorithm for mixed H2/H8 control problem of singularly perturbed systems

In this paper, we study the mixed H     

Equivalent circuit model for electric double layer capacitors and its applications

For a better understanding and detailed analysis of the electric behavior of EDLCs, we present one dynamic equivalent circuit model and two static ones, each of which consists of a resistance and a capacitance varying with voltage. A dynamic model based on the differential capacity is used to simulate the discharging curves. Also, two static models based on the integral and the effective capacity are used to estimate the energy efficiency and constant current charging–discharging time. Owing to the same energy‐oriented approach as is used in defining the effective capacity, the static model based on this capacity shows its superiority in estimating the efficiency and capacitance over another static model based on the integral capacity. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(4): 29–37, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21300     

Cardiovascular Disease Modeling Using Patient-Specific Induced Pluripotent Stem Cells

The generation of induced pluripotent stem cells (iPSCs) has opened up a new scientific frontier in medicine. This technology has made it possible to obtain pluripotent stem cells from individuals with genetic disorders. Because iPSCs carry the identical genetic anomalies related to those disorders, iPSCs are an ideal platform for medical research. The pathophysiological cellular phenotypes of genetically heritable heart diseases such as arrhythmias and cardiomyopathies, have been modeled on cell culture dishes using disease-specific iPSC-derived cardiomyocytes. These model systems can potentially provide new insights into disease mechanisms and drug discoveries. This review focuses on recent progress in cardiovascular disease modeling using iPSCs, and discusses problems and future perspectives concerning their use.     

A strategy for high-speed countercurrent chromatography purification of specific antioxidants from natural products based on on-line HPLC method with radical scavenging assay

We have proposed a novel and first strategy of high-speed countercurrent chromatography (HSCCC) purification for the efficient and effective discovery of antioxidant from natural product based on on-line HPLC method with radical scavenging assay. To achieve a strategy for HSCCC purification, the antioxidants in materials are identified by on-line HPLC with DPPH radical scavenging assay. Then, the optimal condition of target peaks would be investigated for the two-phase solvent system, and purified by HSCCC. In this study, the specific antioxidants in red cabbage, perilla and elderberry pigments were evaluated by on-line HPLC with DPPH radical scavenging assay, and purified by HSCCC technique. Specific antioxidants could be rapidly pinpointed in complex mixtures by on-line HPLC with DPPH radical scavenging assay. Then, the optimal two-phase solvent systems were investigated using these HPLC peaks. Finally, the purification of these nine antioxidants form three mixtures were performed by HSCCC. Using mass spectrometric analysis, these antioxidants were confirmed to cyanidin-based anthocyanin from red cabbage and elderberry pigments, and luteolin-based flavones from perrilla pigment. Due to the advantages derived from on-line HPLC with DPPH radical scavenging assay and HSCCC technique, a rapid, efficient and effective strategy has been developed for the discovery of antioxidants from natural products.     

Performance evaluation of a trace-moisture analyzer based on cavity ring-down spectroscopy: Direct comparison with the NMIJ trace-moisture standard

The performance of a moisture analyzer (MA) based on cavity ring-down spectroscopy (CRDS) was evaluated by direct comparison with the primary trace-moisture standard developed at the National Metrology Institute of Japan (NMIJ). The limit of detection for trace moisture in nitrogen gas by the CRDS-based MA, expressed in amount fraction (mole fraction), was estimated to be 1 nmol mol^?1 or less. The CRDS-based MA showed excellent performance in terms of linearity, accuracy, time response, stability, and reproducibility over four years. It was found for a moderate range of pressures and temperatures that we can measure trace moisture in nitrogen gas with a relative standard uncertainty of approximately 4% down to approximately 10 nmol mol^?1, even using a simple CRDS-based MA that measures only the peak intensity of the absorption line, provided that the MA is properly calibrated on the basis of a reliable trace-moisture standard.