Carrier transport properties in highly ordered smectic liquid crystal phase

We have designed and synthesized a new liquid crystalline phenylbenzothienobenzothiphene derivative, Ph‐BTBT‐4S‐3, in order to investigate the carrier transport properties in highly ordered smectic liquid crystal phase at a wide temperature range lower than room temperature enough to analyze them. Ph‐BTBT‐4S‐3 exhibits smectic E (SmE) phase, which is the one of highly ordered smectic liquid crystal phases, at the wide temperature range from 200°C to under ?130°C. Thanks to its wide temperature range of SmE phase, we could reveal the carrier transport properties in the low temperature range, which were well explained on the basis of Gaussian disorder model having a Gaussian width, σ, of 87 meV, which was larger than those of typical nonpolar liquid crystals of 40?60 meV and was attributed to additional dipole of a thioether group in the side chain.     

Interfacial sol–gel processing for preparation of porous titania particles using a piezoelectric inkjet nozzle

The aim of the present work is to apply the liquid–liquid interfacial crystallization using a piezoelectric inkjet nozzle to the sol–gel processing. The instillation process was compared with the batch process to elucidate the effectiveness of the inkjet technique on the liquid–liquid interfacial sol–gel processing. The effect of frequency and water concentration in titanium tetraisopoxide (TTIP) solution on titania particle properties was investigated for sol–gel processing with a piezoelectric inkjet nozzle. Titania particles produced by each process were calcined at 500 °C. The crystal structure, morphology, pore size distribution and specific surface area of titania particles were evaluated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption measurement. The photocatalytic activity of titania particles was evaluated by the photodegradation of methylene blue solution under UVC light irradiation.     

Predictive cutting force model in complex-shaped end milling based on minimum cutting energy

A force model is presented to predict the cutting forces and the chip flow directions in cuttings with complex-shaped end mills such as ball end mills and roughing end mills. Three-dimensional chip flow in milling is interpreted as a piling up of the orthogonal cuttings in the planes containing the cutting velocities and the chip flow velocities. Because the cutting thickness changes with the rotation angle of the edge in the milling process, the surface profile machined by the previous edge inclines with respect to the cutting direction. The chip flow model is made using the orthogonal cutting data with taking into account the inclination of the pre-machined surface. The chip flow direction is determined so as to minimize the cutting energy, which is the sum of the shear energy on the shear plane and the friction energy on the rake face. Then, the cutting force is predicted for the chip flow model at the minimum cutting energy. The predicted chip flow direction changes not only with the local edge inclination but also with the cutting energy consumed in the shear plane cutting model. The cutting processes with a ball end mill and a roughing end mill are simulated to verify the predicted cutting forces in comparison with the measured cutting forces.     

Neuron Membrane Trafficking and Protein Kinases Involved in Autism and ADHD

A brain-enriched multi-domain scaffolding protein, neurobeachin has been identified as a candidate gene for autism patients. Mutations in the synaptic adhesion protein cell adhesion molecule 1 (CADM1) are also associated with autism spectrum disorder, a neurodevelopmental disorder of uncertain molecular origin. Potential roles of neurobeachin and CADM1 have been suggested to a function of vesicle transport in endosomal trafficking. It seems that protein kinase B (AKT) and cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) have key roles in the neuron membrane trafficking involved in the pathogenesis of autism. Attention deficit hyperactivity disorder (ADHD) is documented to dopaminergic insufficiencies, which is attributed to synaptic dysfunction of dopamine transporter (DAT). AKT is also essential for the DAT cell-surface redistribution. In the present paper, we summarize and discuss the importance of several protein kinases that regulate the membrane trafficking involved in autism and ADHD, suggesting new targets for therapeutic intervention.     

Protease susceptibility of beta-lactoglobulin adsorbed on stainless steel surface as evidence of contribution of its specific segment to adsorption

beta-Lactoglobulin (beta-Lg) is a major constituent of fouling deposits in the dairy industry. To determine the interaction between beta-Lg and stainless steel surfaces, beta-Lg irreversibly adsorbed on stainless steel particles was subjected to lysyl endopeptidase treatment and the course of fragmentation was compared with that observed for beta-Lg in solution. The results showed a distinct difference between the courses of fragmentation: a fragment (residues 102-135) was liberated readily from beta-Lg in solution but scarcely from beta-Lg irreversibly adsorbed on stainless steel particles. This result strongly suggests that residues 102-135 include a segment primarily responsible for the interaction of beta-Lg with stainless steel surfaces. This supports our previous results [Sakiyama et al., J. Biosci. Bioeng., 88, 536-541 (1999)] that showed that residues 125-135 of beta-Lg have a strong affinity toward stainless steel surfaces and probably a major contribution to the adsorption of beta-Lg.     

Bacterial contamination in an egg-breaking factory and its control

From January to November, 2003, bacterial contamination was surveyed in a small egg-breaking factory that produced non pasteurized liquid egg. Test egg samples were taken at various stages of the egg processing operation. Salmonella Enteritidis was isolated from liquid egg yolk and liquid egg white on October, but was not found in any other samples (50 liquid egg samples, 21 containers and 94 attached production facilities and gloves). The data suggest that the contamination rate (3.8%) is lower than those reported previously. Levels of bacterial standard plate counts, gram-positive bacterial counts and gram-negative bacterial counts were in the ranges of 2 to 5 log CFU/g, 2 to 3 log CFU/g, 2 to 5 log CFU/g, respectively. Liquid egg containers returned from customers was contaminated with bacteria at the level of 8 log CFU per container. However, washing and application of a sanitizer containing sodium hypochlorite reduced the bacterial counts.     

Dramatic effect of dispersed carbon nanotubes on the mechanical and electroconductive properties of polymers derived from ionic liquids

Free-radical polymerization of an imidazolium ion-based ionic liquid bearing a methacrylate group, gelling with single-walled carbon nanotubes (SWNTs), allows fabrication of a mechanically reinforced, electroconductive soft material (bucky plastic). A film sample of this material displays an excellent conductivity of 1 S cm(-1) and a 120-fold enhancement of the Young's modulus at a 7 wt % content of SWNTs. The conductivity is temperature-dependent in the range 5-300 K, suggesting that the conductive process involves carrier hopping. Scanning electron and atomic force micrographs of a bucky plastic film display the presence of crosslinked networks consisting of finely dispersed SWNTs. Such nanotube networks, developed in the polymer matrix, likely suppress slipping of entrapped polymer molecules via a strong interfacial interaction and also facilitate intertubular carrier transport. Although a bucky plastic derived from a vinylimidazolium ion-based ionic liquid monomer shows a comparable conductivity to that of the methacrylate version, the film is brittle irrespective of the presence or absence of SWNTs.     

Absolute quantitation of quercetin and the glycosides in natural food additives by quantitative NMR

We are developing a simple absolute quantitation method for organic compounds, by means of quantitative nuclear magnetic resonance (qNMR), with traceability to the International System of Units (SI units). The qNMR method was applied to the absolute quantitation of rutin, isoquercitrin and quercetin in natural food additives, rutin (extract), enzymatically decomposed rutin extract and quercetin, and those compounds as commercial reagents. In this study, 1,4-bis-(trimethylsilyl)benzene-d(4) (1,4-BTMSB-d(4)) whose purity was precisely evaluated on the basis of metrology, was newly used as a qNMR reference material, to be added to the sample solution as an internal standard. The contents of quercetin and quercetin glycosides were calculated from the ratio of the signal intensities of each aromatic proton at the 2' position of the three compounds (these are observed at different chemical shifts) to the eighteen protons of the six methyl groups on 1,4-BTMSB-d(4) used as a qNMR reference material. Rapid and simple qNMR method with only one step process was carried by using 1,4-BTMSB-d(4). It was demonstrated that the purities of rutin, isoquercitrin and quercetin can be separately determined by qNMR without the need for a separation process or reference materials for all the target compounds.     

Effect of the growth rate of Pseudomonas aeruginosa biofilms on the susceptibility to antimicrobial agents: beta-lactams and fluoroquinolones

The combined effects of meal cost and food flavor on meal size were studied with a method that avoided the covariation of nutrient composition and caloric density with palatability. As rats (Rattus norvegicus) drank flavored fluids (unpalatable 0.05% sucrose octaacetate [SOA], neutral 0.05% saccharin, and palatable 2% Polycose + 0.2% saccharin [P + S]), liquid diet was infused intragastrically. Relative to saccharin, rats with free access ate 10% more calories in larger meals while consuming P + S and initially ate fewer calories in smaller but more frequent meals while drinking SOA. Other rats lever-pressed to begin meals, which halved meal number and doubled meal size relative to the free-access group. Although foraging rats also ate larger P + S meals and smaller SOA meals, the changes did not affect total intake. Without the usual differential postingestive effects of foods that differ in palatability, making food more costly blunts rats' response to its flavor.