Lonophore-based lithium ion film optode realizing multiple color variations utilizing digital color analysis

Digital color analysis (DCA), utilizing colors themselves or digital information of colors, can not only be applied to various quantitative analysis using chromaticity coordinates but can also be used to develop suitable sensors for visual colorimetry based on the characteristics of human visual perception by virtual simulations based on digital color information. To achieve a clear visual color variation for lithium ion determination, we designed and prepared a color-changeable film sensor (film optode) by the use of two kinds of lipophilic dyes, KD-C4 and KD-M11, whose colors and pKa values are different. This film sensor is a plasticized PVC membrane containing the mixture of two kinds of dyes with the lithium ionophore TTD14C4 and the lipophilic anionic additive tetrakis-[3,5-bis(trisfluoromethyl)phenyl]borate sodium salt dihydrate. The simulation of the color variation using the mixed dyes was evaluated by plotting the values on a uniform chromaticity scale diagram in a*b* coordinates, after converting the tristimulus values of each dye into its L*a*b* values. When the lithium ion concentration was actually determined by the PVC film optode containing the mixed dyes whose molecular ratio of KD-C4/KD-Ml 1 was 3:1, the hues of red --> orange --> yellow --> green --> blue could be realized in the range of 10(-6)-1 M. This observed color variation was similar to the result of the virtual simulation based on DCA.     

Cloning and chromosomal mapping of URA3 genes of Pichia farinosa and P. sorbitophila encoding orotidine-5'-phosphate decarboxylase

The PfURA3 gene, which encodes orotidine-5'-phosphate decarboxylase, of osmotolerant yeast Pichia farinosa NFRI 3,621, was cloned by complementation of the ura3 mutation of Saccharomyces cerevisiae. The nucleotide sequence of the PfURA3 gene and its deduced amino acid sequence indicated that the gene encodes a protein (PfUra3p) of 267 amino acids. Pulsed-field gel electrophoresis and subsequent Southern blot analysis showed that the genome of P. farinosa NFRI 3621 consisted of seven chromosomes, each approximately 1.1-2.2 Mb in size (11.8 Mb in total) and that PfURA3 was located on chromosome V. Pichia sorbitophila is considered as a synonym of P. farinosa. The genome of P. sorbitophila IFO10021 may consist of 12 chromosomes, each approximately 1.2-2.2 Mb in size. P. sorbitophila has two copies of URA3 genes, termed PsURA3 and PsURA30, which were located on chromosome VIII and III, respectively. The difference between PfURA3 and PsURA3 was only two amino acid substitutions, whereas that between PsURA3 and PsURA30 was six amino acid substitutions and the deletion of the C-terminal amino acid by a stop codon insertion. The sequences of PfURA3, PsURA3 and PsURA30 have been deposited in the DDBJ data library under Accession Nos AB071417, AB109042 and AB109043, respectively.     

Improving cache attacks by considering cipher structure

A concrete attack using side channel information from cache memory behaviour was proposed for the first time at ISITA 2002. The attack uses the difference between execution times associated with S-box cache-hits and cache-misses to recover the intermediate key. Recently, a theoretical estimation of the number of messages needed for the attack was proposed and it was reported that the average method obtains key information with fewer messages than maximum threshold or intermediate threshold method. Taking the structure of cipher into account, this paper provided the cache attack in which the average method is embodied, and provides improved key estimation. This paper includes the study on the attack that exploits internal collision. Yukiyasu Tsunoo received his BE degree from Waseda University in 1982, MS degree from JAIST, Dr.Eng from Chuo University. He joined NEC Software Hokuriku, Ltd. in 1985. He is now a research fellow of NEC Internet Systems Research Laboratories. He is engaged in the designing of common key ciphers and the study of evaluation technique. Dr. Tsunoo is a member of the Expert Commission of Information Security Research, The Institute of Electronics, Information and Communication Engineers, the Information Processing Society of Japan, the Japan Society for Security Management and the Atomic Energy Society of Japan. Etsuko Tsujihara received her BS degree from Aoyama Gakuin University in 1983. She joined NEC in 1983. She developed the VLSI automatic layout system. She joined NEC Software Hokuriku Ltd. in 1986 and Y.D.K. Co. Ltd. in 2004. She is engaged in the designing of common key ciphers and the study of evaluation technique. Maki Shigeri received her BE degree from University of Tsukuba in 1992. She joined NEC Software Hokuriku Ltd. in 1992. She is engaged in the designing of common key ciphers and the study of evaluation technique. Hiroyasu Kubo received his BE degree from Kanazawa Institute of Technology in 1990. He joined NEC Software Hokuriku Ltd. in 1990. He is engaged in the designing of common key ciphers and the study of evaluation technique. Kazuhiko Minematsu received his BS degree from Waseda University in 1996, MS degree in 1998 and joined NEC in 1998. He is engaged in the designing of common key ciphers and research on block cipher modes of operations. He is a member of the Information Processing Society of Japan, the Society of Information Theory and Its Applications.     

HPLC Analysis of Catechins, Theaflavins, and Alkaloids in Commercial Teas and Green Tea Dietary Supplements: Comparison of Water and 80% Ethanol/Water Extracts

ABSTRACT:  To help meet the needs of consumers, producers of dietary tea supplements, and researchers for information on health-promoting tea compounds, we compared the following conditions for the extraction of tea leaves and green tea-containing dietary supplements: 80% ethanol/water at 60 °C for 15 min and boiled water for 5 min. The following 7 catechins, 4 theaflavins, and 3 alkaloids were separated in a 70-min single HPLC analysis: (−)-epigallocatechin, (−)-catechin, (+)-epicatechin, (−)-epigallocatechin-3-gallate, (−)–gallocatechin-3-gallate, (−)-epicatechin-3-gallate, (−)-catechin-3-gallate, theaflavin, theaflavin-3-gallate, theaflavin-3'-gallate, theaflavin-3,3'-digallate, caffeine, theobromine, and theophylline. The following ranges of concentrations of flavonoids (catechins plus theaflavins) in the tea leaves extracted with 80% ethanol were observed (in mg/g): in 32 black teas, 19.8 to 115.1; in 24 green teas, 12.3 to 136.3; in 14 specialty teas, 4.9 to 118.5; in 7 herbal teas, 0 to 46.0. Total alkaloids in all teas ranged from 0 to 32.6 mg/g. Significantly greater amounts of flavonoids were extracted from the tea leaves with aqueous ethanol than with boiled water. Levels of tea catechins in 10 capsules sold as dietary supplements were about 50 to 75% lower than the amounts listed on the labels. Catechin content of 4 commercial green tea extracts ranged from 96 to 696 mg/g. The results make it possible to maximize the extraction of tea compounds to better relate the flavonoid and alkaloid content of teas and dietary tea supplements to their health-promoting effects.     

Determination of antioxidant activity of herbs by ESR

Water extracts of 32 herbs that are constituents of curry and curry powder were screened for superoxide anion radical (O2.-) scavenging activity. Among the screened samples, only clove, allspice, and basil were shown to decrease DMPO-O2.- adduct yields by more than 50% at 0.25 mg/mL as measured by an ESR spin trapping technique based on the HPX-XOD reaction. To study the mechanism of the O2.- scavenging activity, Km values were obtained from a Lineweaver-Burk plot for XOD in the presence of different concentrations of HPX, and the IC50 values at different DMPO concentrations were compared. Clove and basil directly eliminated O2.- like superoxide dismutase (SOD), whereas allspice reduced the amount of O2.- by inhibition of formation of O2.-.     

Secure and Defensive High Self-Esteem.

Long-standing theories have suggested high self-esteem (SE) can assume qualitatively different forms that are related to defensiveness. The authors explored whether some high-SE individuals are particularly defensive because they harbor negative self-feelings at less conscious levels, indicated by low implicit SE. In Study 1, participants high in explicit SE but low in implicit SE showed the highest levels of narcissism--an indicator of defensiveness. In Studies 2 and 3, the correspondence between implicit and explicit SE predicted defensive behavior (in-group bias in Study 2 and dissonance reduction in Study 3), such that for high explicit-SE participants, those with relatively low implicit SE behaved more defensively. These results are consistent with the idea that high SE can be relatively secure or defensive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phase-field modeling for facet dendrite growth of silicon

Dendrite growth of silicon from its undercooled melt was investigated by using the phase-field model for a faceted crystal with anisotropic interfacial energy. The phase-field parameters at the thin interface limit were derived and used in the simulation. The accuracy of the model was estimated from the calculated equilibrium interface shape. The errors in anisotropy and Gibbs-Thomson coefficient were within 1% and 10%, respectively. The growth of a silicon crystal from its undercooled melt has been analyzed and it is shown that the shape of growing crystal changes from square-like to dendritic with increase of undercooling. In a facet dendrite growth the tip grows keeping its shape and the shape is the same regardless of undercooling or growth velocity. It is also shown that there exists the scaling law between the characteristic length of the tip and growth velocity similar to that of a non-facet dendrite.     

Difference in carbo-thermal reduction reaction kinetics of NiO in microwave E- and H-fields

A powder mixture of NiO and graphite was heated in a single mode-microwave (MW) applicator at 2.45 GHz for carbo-thermal reduction of NiO. The specimen was placed in the wave guide at maximum positions of either electric (E) field or magnetic (H) field and kept at a constant temperature.A tendency was observed that the reduction rate at 600 °C was larger in the H-field than in the E-field. Considering the fact that NiO can be heated only in the E-field, while graphite can be heated in both fields, graphite particles in the powder mixture might be selectively heated in the H-field. Hence, it is postulated that a microscopic temperature gradient is formed more in the H-field, which caused the gas convection, then the mass transfer and the gas-solid reaction is enhanced, so the enhanced reduction kinetics resulted, eventually.     

Melt viscosity of acrylic copolymers

The melt flow behavior of methyl methacrylate (MMA) copolymerized with methyl acrylate (MA) was measured and analyzed in terms of the molecular structure of the copolymers. Measurement was done by using a capillary rheometer in the shear rate range from 6 × 10⁰ to 3 × 10³ s^?1 and in temperatures from 160°C to 280°C. The Newtonian flow pattern appeared in lower shear rate and higher temperature regions. However, with increasing shear rate at lower temperature, viscosity decreased to a constant slope on a logarithmic scale. The melt fracture arose at the critical shearing stress point S_c of 6 × 10⁶ dyn/cm². A die swell also appeared in the shear rate range larger than 1 × 10⁶ dyn/cm², and its maximum value was two times larger than that of the capillary diameter. The decrease in viscosity with increasing shear rate is explained in terms of the apparent energy of activation in flow E. E also decreases with increasing shear rate. The exponential relation of E to η is maintained in the higher shear rate. The lowering of viscosity in lower shear rate, however, is attributed to not only the change in E but also the change in the volume of flow unit. The melt viscosity increases in inverse proportion to the MA content in the copolymers which form more flexible chains. Syndiotactic form of MMA has increased viscosity, caused by the rigidifying of segmented chains, rather than the strengthening of intermolecular interaction.