Development of fermented instant Chinese noodle using Lactobacillus plantarum

A new-type of instant Chinese noodle was developed with the application of lactic acid fermentation by lactobacilli. Since the pH value of the noodle sheets is alkaline with kansui (around 8.5), alkaline tolerance is required for the lactobacilli to ferment noodle sheets. The screening of the lactobacilli strains suitable for the fermentation was conducted using 46 strains from 12 species (including subspecies) of lactobacilli. Several strains of Lactobacillus pentosus and Lactobacillus plantarum were found to be fermenters. Among these, L. plantarum NRIC 0380, that showed the highest fermentation rate and favorable modification of noodle, was selected as the best strain, and was employed for the pilot scale manufacture of instant Chinese noodle. During fermentation, L. plantarum NRIC 0380 produced lactic acid to about 11 g/kg noodle sheet after 24 h with a concomitant pH decrease from an initial of about 7.9 down to 3.9. Sensory test after rehydration with boiled water revealed that the fermented instant Chinese noodle sheets at pH 7.5 had increased hardness, elasticity and light sour taste.     

Evaluation of a loop-mediated isothermal amplification assay for rapid and simple detection of Vibrio parahaemolyticus in naturally contaminated seafood samples

We investigated the efficacy of a loop-mediated isothermal amplification (LAMP) assay for rapid screening of seafood samples naturally contaminated with Vibrio parahaemolyticus. A total of 171 seafood samples enriched in alkaline peptone water (APW) were assessed by LAMP assay and conventional culture methods, which consist of a combination of APW enrichment culture and plating onto CHROMagar Vibrio and TCBS agars. Compared with V. parahaemolyticus isolation using the conventional culture test, LAMP results showed 100% (30/30) and 90.8% (128/141) sensitivity and specificity, respectively. The conventional culture test required more than 3 days to isolate and identify V. parahaemolyticus in the APW enrichment culture. In contrast, the LAMP assay was markedly faster, requiring less than 60 min from the beginning of DNA extraction to final detection of V. parahaemolyticus. In total, the LAMP assay required 17-19 h from the beginning of enrichment culture to final determination. This is the first report of the LAMP assay for rapid screening of seafood samples naturally contaminated by V. parahaemolyticus.     

Conductive area ratio of multiblock copolymer electrolyte membranes evaluated by e-AFM and its impact on fuel cell performance

The correlation between membrane surface morphology and fuel cell performance was investigated using a series of hydrophilic–hydrophobic multiblock copolymers based on poly(arylene ether sulfone) with different block lengths. The proton conductive regions on the membrane surface were successfully observed by using electrochemical atomic force microscopy (e-AFM). The results revealed a strong dependence of the hydrophilic/hydrophobic microphase-separated structure on the block length. The conductive area ratio (CAR) estimated from the proton conduction image decreased as the block length increased, and it was found to be closely connected with cell resistance that determines fuel cell performance. The well-defined phase-separated structure of multiblock copolymers can improve proton conductivity without any undesirable increments in water uptake or swelling, but in some instances, it affects the interfacial connection with the catalyst layer, resulting in lower fuel cell performance. The results of this study suggest the necessity for further improvement of the membrane morphology by optimizing both the casting conditions and the molecular design of the block sequences.     

Double Elimination Protocol for Convenient Synthesis of Dihalodiphenylacetylenes: Versatile Building Blocks for Tailor‐Made Phenylene‐Ethynylenes

Dihalodiphenylacetylenes are conveniently synthesized by a double elimination reaction of β‐substituted sulfones which are readily obtained from halogen‐substituted benzyl sulfone and benzaldehyde derivatives. Halogens can be incorporated at any desired positions in the diphenylacetylene skeleton simply by choosing the substitution position of the halogen on the aromatic rings of the starting compounds. The diphenylacetylenes with different halogen substituents thus obtained undergo sequential carbon‐carbon bond formations due to the different reactivities of the halogens. Thus, various moieties can be incorporated on the diphenylacetylene skeleton at whichever positions so that a variety of tailor‐made phenylene‐ethynylenes with regulated structure and composition could be designed.     

Spatiotemporally Controllable Chemical Delivery Utilizing Electroosmotic Flow Generated in Combination of Anionic and Cationic Hydrogels

Spatiotemporally controlled chemical delivery is crucial for various biomedical engineering applications. Here, a novel concept of electrically controllable delivery utilizing electroosmotic flow (EOF) generated in a combination of anionic and cationic hydrogels (A- and C-hydrogels) is reported. The unique advantages of the A/C-hydrogel combination are demonstrated utilizing a flexible sheet-shaped and a thin tubular devices. Since the directions of EOF in the A- and C-hydrogels are opposite to each other, the ionic current for EOF generation flows inside the delivery devices, enabling chemical delivery without accompanying external ionic current that could stimulate target cells and tissues. A thin tubular device, which can be inserted into narrow in vivo structures and be integrated with other flexible devices, exhibits high robustness and repeatability thanks to the flexibility and water retentivity of hydrogels. The EOF devices with A/C-hydrogels combination show high controllability superior to the pumping with a conventional syringe; the volumetric flow rate is able to be controlled proportionally to the current applied, for example, ≈0.4 µL (mA min)⁻¹ for the tubular device. The developed EOF-based devices are versatile for delivery of most chemicals regardless of their charge and size, and have great potential for both biomedical researches and therapeutics.     

Studies on new type of phenolic resin (IX) curing reaction of bisphenol A‐based benzoxazine with bisoxazoline and the properties of the cured resin. II. Cure reactivity of benzoxazine

Bisphenol A‐based benzoxazine that contained oligomers (oligo‐Ba) was prepared from bisphenol A, formaline, and aniline. Curing reaction of oligo‐Ba with bisoxazoline and the properties of the cured resin were investigated. Consequently, the ring‐opening reaction of benzoxazine ring occurred, and then the phenolic hydoroxyl group generated by the ring‐opening reaction of benzoxazine ring reacted with oxazoline ring. It was found that the cure induction time and cure time of the molten mixture from oligo‐Ba and bisoxazoline could be reduced and also the cure temperature could be lowered, compared with those from bisphenol A‐based benzoxazine, which contained no oligomers (Ba), and bisoxazoline. The melt viscosity of the molten mixture from oligo‐Ba and bisoxazoline was kept 0.1–10 [Pas] at 140°C even after 40 min, the molten mixture from oligo‐Ba and bisoxazoline showed good flowability below 140°C as well as that from Ba and bisoxazoline. However, above 160°C the curing reaction of oligo‐Ba with bisoxazoline proceeded more rapidly than that of Ba with bisoxazoline. The cured resin from oligo‐Ba and bisoxazoline showed good heat resistance and water resistance, compared with the cured resin from Ba and bisoxazoline. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2331–2339, 2001     

Zone drawing and zone annealing of poly(ethylene terephthalate) microfiber prepared by CO2 laser thinning

A zone‐drawing and zone‐annealing method was applied to a poly(ethylene terephthalate) microfiber, obtained by using CO₂ laser thinning, to develop its mechanical properties. The microfiber used for the zone drawing and zone annealing was prepared by winding at 1386 m/min the microfiber obtained by irradiating the laser at 18.1 W/cm² and had a diameter of 2.8 μm and a birefringence of 0.097. Zone drawing was carried out at a drawing temperature of 105°C under an applied tension of 53 MPa, and zone annealing at an annealing temperature of 155°C under 195 MPa applied tension. Zone drawing and zone annealing were carried out at a treatment speed of 0.21 m/min. The diameter of the microfiber decreased, and its birefringence increased, with zone drawing and zone annealing. The zone‐annealed microfiber finally obtained had a diameter of 2 μm, a birefringence of 0.234, a tensile modulus of 17.9 GPa, and a tensile strength of 1.1 GPa. The wide‐angle X‐ray diffraction photograph of the zone‐annealed microfiber showed the existence of highly oriented crystallites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2989–2994, 2004     

First-principles study on cerium ion behavior in irradiated cerium dioxide

In order to clarify, from the electronic structure, the origin of the appearance of the tri-valent Ce state in irradiated cerium dioxide with swift heavy ions, we performed comprehensive first-principles calculations on various defective structures in cerium dioxide. The calculated results show that an oxygen mono-vacancy or an oxygen Frenkel pair can induce two tri-valent Ce states neighboring the oxygen vacancy. The calculation of the oxygen Frenkel pair further reveals that an interstitial oxygen atom that moves from the lattice position and an oxygen atom on the lattice can form a dimer that behaves as an oxygen molecule of negative di-valence. This bonding state can also produce excess electrons and the tri-valent Ce state in cerium dioxide.     

Simultaneous measurement of harmonics by a new measuring method

A harmonic measuring instrument using PICmicro® Microcontroller (PIC) and Phase Locked Loop (PLL), which was discussed in an earlier paper, has been improved. The developed instrument enables a continuous measurement for several days by an additional PIC for power management. A postprocessing program running on a Personal Computer (PC) has also been developed to rearrange the enormous data obtained by multipoint measurements. The developed instrument and the program make the observation of harmonic distribution easier. Harmonic measurements were carried out in buildings of a university campus with the developed instruments. The results shows that rectifier circuits within a building are sources of the harmonic voltages, while a distortion at another building is caused by a harmonic expansion due to a resonance between a line inductance and capacitances for power compensation. The measured characteristics are also confirmed by numerical simulations using Electro‐Magnetic Transient Program (EMTP). © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Modeling of a buried conductor for an electromagnetic transient simulation

The paper has proposed a distributed‐line model of a buried bare conductor with horizontal and vertical configuration by assuming an artificial insulator outside of the bare conductor so that the characteristic impedance and the propagation velocity of the buried conductor is evaluated as an insulated conductor (cable) by the cable constants/parameters of the EMTP. A shunt admittance is added to the conductor at every short distance to represent currents flowing into the earth from the original bare conductor. The admittance circuit and the parameters are evaluated either by experimental results or by published references of grounding electrodes. The model circuit has been applied to simulate transient currents and voltages on horizontal and vertical buried conductors, and the simulation results are compared with the measured results. It has been observed that the simulation results of the currents agree satisfactorily with the measured results, but the results of the voltages do not seem satisfactory. The reason for this has been discussed based on the measured results. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.