Origin of the thermal plasticity property of zirconium oxide gels for use in direct thermal nanoimprinting

Some types of oxide gels derived from solutions exhibit a thermal plasticity property. In our previous report, the thermal plasticity property was utilized to produce oxide patterns and thin film transistors. However, it was not clear why some oxide gels exhibited a thermal plasticity property. In this report, we prepared not only a plastic ZrO₂ gel but also a non-plastic ZrO₂ gel, and investigated the structural and thermal properties of these gels to clarify why some gels exhibit a thermal plasticity property. We identified a clustered structure in ZrO₂ gels, with a Zr-O-Zr core coordinated by organic ligands. This structure was strongly related to the thermal plasticity property. The thermal plasticity property of ZrO₂ gel resulted from desorption and oxidization of the extra ligands by heating. We determined that the plastically deformed gels were consisted of clusters, and that the behaviour of ligands was a trigger in making a gel plastically deformed.     

Diffusion of p-aminoazobenzene in SBS block copolymer

The temperature dependence of p-aminoazobenzene diffusion in a styrene–butadiene–styrene (SBS) triblock copolymer film, prepared from a toluene or ethyl acetate solution, was investigated in the temperature region from 40° to 110°C by using a sublimative desorption method. Parallel studies on the mechanical relaxations of this copolymer were carried out in the same temperature range to be compared with the diffusion data. The penetrant-diffusion characteristics were interpreted in terms of Fujita's free-volume theory with due consideration of the different SBS domain morphology. The value of B_d, defined as the diffusional volume ratio of a penetrant molecule to a segment, was then estimated as 0.45–0.55 above the T_g of the polystyrene phase or 0.7 below that temperature. Interestingly, sigmoidal desorption appeared in the range under the T_g of the polystyrene phase for film cast from ethyl acetate; the anomalous behavior was considered to reflect the slow relaxation process of the copolymer chain ascribable to the predominant exposure of the polystyrene phase on the film surface.     

Development of Microstructures of Long-Period Stacking Ordered Structures in Mg85Y9Zn6 Alloys Annealed at 673 K (400 °C) Examined by Small-Angle X-Ray Scattering

Development of LPSO structure and in-plane ordering during annealing the Mg85Y9Zn ternary alloy sample at 673 K (400 °C) was examined by synchrotron radiation small-angle scattering/diffraction measurements. By examining the first diffraction peaks for 18R, 10H, and in-plane order spot, the growth kinetics of in-plane order domain and the transition from 10H into 18R were discussed. The domain growth of in-plane order was characterized by small domain with little correlation between neighboring segregation layers.     

Diversity of calcium signaling by metabotropic glutamate receptors

During prolonged application of glutamate (20 min), patterns of increase in intracellular Ca2+ concentration ([Ca2+]i) were studied in HEK-293 cells expressing metabotropic glutamate receptor, mGluR1alpha or mGluR5a. Stimulation of mGluR1alpha induced an increase in [Ca2+]i that consisted of an initial transient peak with a subsequent steady plateau or an oscillatory increase in [Ca2+]i. The transient phase was largely attributed to Ca2+ mobilization from the intracellular Ca2+ stores, but the sustained phase was solely due to Ca2+ influx through the mGluR1alpha receptor-operated Ca2+ channel. Prolonged stimulation of mGluR5a continuously induced [Ca2+]i oscillations through mobilization of Ca2+ from the intracellular Ca2+ stores. Studies on mutant receptors of mGluR1alpha and mGluR5a revealed that the coupling mechanism in the sustained phase of Ca2+ response is determined by oscillatory/non-oscillatory patterns of the initial Ca2+ response but not by the receptor identity. In mGluR1alpha-expressing cells, activation of protein kinase C selectively desensitized the pathway for intracellular Ca2+ mobilization, but the mGluR1alpha-operated Ca2+ channel remained active. In mGluR5a-expressing cells, phosphorylation of mGluR5a by protein kinase C, which accounts for the mechanism of mGluR5a-controlled [Ca2+]i oscillations, might prevent desensitization and result in constant oscillatory mobilization of Ca2+ from intracellular Ca2+ stores. Our results provide a novel concept in which oscillatory/non-oscillatory mobilizations of Ca2+ induce different coupling mechanisms during prolonged stimulation of mGluRs.     

Polymer blends of polyethersulfone with all aromatic liquid crystalline co-polyester

Polymer blends of polyethersulfone (PES) with an all aromatic liquid crystalline co-polyester (LCP) were investigated. In addition, PES oligomers with the reactive functions end groups (?ONa) were added as a third component to the above blends in order to improve their properties. Flexural properties, such as modulus and strength, and dynamic viscoelastic properties, such as dynamic storage elasticity (E′) and loss tangent (tan δ), of the blends were measured. The morphology of blends was characterized using a differential scanning calorimeter (DSC) and a scanning electron microscope (SEM). Of the flexural properties, the modulus of PES increased almost linearly with increasing LCP content. However, strength decreased as LCP content increased to 20 wt%. In contrast, the addition of the PES oligomers had little effect on modulus, but strength was clearly improved. Regarding dynamic viscoelastic properties, the oligomer-containing blends exhibited complex behavior. Regarding morphologies, SEM analysis revealed that the LCP was not fibrous in the core of the blend containing 40 wt% or less, but the addition of the PES oligomers made LCP fibrous even in blends with low LCP content. It was concluded that the PES oligomers with reactive functional groups acted as a compatibilizer in polymer blends of PES/LCP.     

Change in the composition of the microflora on vacuum-packaged beef during chiller storage

Five fresh beefcut samples were divided into 10 pieces, respectively, vacuum-packaged and stored at 2 degrees C for up to 6 weeks. The average pH values of five pieces from five beef samples were 5.62 +/- 0.04 at the start of storage and 5.12 +/- 0.07 after 6 weeks of storage. The pieces were homogenized, diluted and cultivated at weekly intervals on glucose-blood-liver (BL), de Man Rogosa and Sharpe (MRS) and trypticase soya (TS) agars at 7 degrees C for 10-14 days. From plates with 30-300 colonies, or the highest number if below 30, 15 colonies were randomly picked from each of the three media used for each beef sample. Based on morphologies, SDS-PAGE whole-cell protein profiles and physio-chemical characteristics, a total of 1493 strains isolated were identified as Brochothrix thermosphacta (64), Carnobacterium divergens (79), Carnobacterium piscicola (27), Lactobacillus algidus (637), Lactobacillus sp. (4), Lactococcus piscium (270), Leuconostoc gelidum (375), Acinetobacter (3), Aeromonas (1), Bacillus (10), Corynebacterium (3), Enterobacteriaceae (1), Pseudomonas (13) or Psychrobacter (6). A wider range of organisms was isolated from TS (13 organisms) and BL (7) agars than from MRS agar (3). Leuc. gelidum, Lc. piscium and L. algidas increased in numbers during the first 3 weeks of storage from about 5 x 10(3) cfu/g to the level of about 10(8) cfu/g and persisted at this level thereafter. C. divergens and C. piscicola were inconsistently detected, but seemed to persist at the relatively low level of about 5 x 10(7) cfu/g during the last 3 weeks of storage. B. thermosphacta increased to the level of about 7 x 10(5) cfu/g during the first 2 weeks of storage, but was not detected thereafter. Remaining organisms were detected sporadically at levels of <3.5 x 10(2) cfu/g during the first 2 weeks of storage.     

Synthesis and angiotensin II receptor antagonistic activities of benzimidazole derivatives bearing acidic heterocycles as novel tetrazole bioisosteres

The design, synthesis, and biological activity of benzimidazole-7-carboxylic acids bearing 5-oxo-1,2,4-oxadiazole, 5-oxo-1,2,4-thiadiazole, 5-thioxo-1,2,4-oxadiazole, and 2-oxo-1,2,3,5-oxathiadiazole rings are described. These compounds were efficiently prepared from the key intermediates, the amidoximes 4. The synthesized compounds were evaluated for in vitro and in vivo angiotensin II (AII) receptor antagonistic activities. Most were found to have high affinity for the AT1 receptor (IC50 value, 10(-6)-10(-7)M) and to inhibit the AII-induced pressor response (more than 50% inhibition at 1 mg/kg po). The 5-oxo-1,2,4-oxadiazole, 5-oxo-1,2,4-thiadiazole, and 5-thioxo-1,2,4-oxadiazole derivatives showed stronger inhibitory effects than the corresponding tetrazole derivatives, while their binding affinities were weaker. This might be ascribed to their improved bioavailability by increased lipophilicity. The 5-oxo-1,2,4-oxadiazole derivative 2 (TAK-536) and 5-oxo-1,2,4-thiadiazole derivative 8f showed efficient oral bioavailability without prodrug formation. This study showed that the 5-oxo-1,2,4-oxadiazole ring and its thio analog, the 5-oxo-1,2,4-thiadiazole ring, could be lipophilic bioisosteres for the tetrazole ring in nonpeptide AII receptor antagonists.