Numerical simulations of sonochemical production of BaTiO3 nanoparticles

Numerical simulations of sonochemical production of nanoparticles have been performed for the first time under the experimental condition of Dang et al. [Jpn. J. Appl. Phys. 48 (2009) 09KC02] on the production of BaTiO(3). The results of the numerical simulations have suggested that only primary particles aggregate with other particles. It is also shown that larger aggregates are produced for lower initial concentration of BaCl(2) and TiCl(4). This is caused by longer reaction time as the reaction rate is lower for lower concentration and by lower viscosity which results in higher rate of aggregation.     

QSNPlite, a software system for quantitative analysis of SNPs based on capillary array SSCP analysis

We present a newly developed software called "QSNPlite" that comprehensively interprets the data of SSCP and sequencing analyses obtained from capillary array electrophoresis systems used in the quantitative characterization of SNPs. QSNPlite assists in the genotyping of individuals with SNPs and in estimating the allele frequencies of SNPs using pooled DNA. We show that this estimation is accurate (mean absolute error, 1.4%) by comparing the results of the pooled analysis using QSNPlite with the true frequencies based on the allele counting after performing individual genotypings. The QSNPlite program runs on Windows XP and can be used to determine the allele frequencies of SNPs among a large number of individuals, such as in association studies of disease-responsible genes using the candidate gene approach.     

Matrix certified reference materials for environmental monitoring from the National Metrology Institute of Japan (NMIJ)

Matrix certified reference materials (CRMs) are playing an increasingly important role in environmental monitoring in Japan. The National Metrology Institute of Japan (NMIJ)/National Institute of Advanced Industrial Science and Technology (AIST) has been developing matrix CRMs for environmental monitoring since 2001, and has issued nine kinds of CRMs as NMIJ CRMs. The development of the CRMs was conducted in NMIJ in cooperation with candidate material producers. The isotope dilution mass spectrometry (IDMS) was principally adopted to give reliable certified values. Meanwhile, two or more analytical methods, whose levels of accuracy were well evaluated, were applied to avoid any possible analytical bias. Two typical certification processes, the certification of river water CRMs for trace element analysis and that of marine sediment CRMs for PCB and organochlorine pesticide analysis, are outlined as examples. Presented at -- “BERM-10” -- April 2006, Charleston, SC, USA.     

Metal-assisted assembly of pyridine-containing arylene ethynylene strands to enantiopure double helicates

Pyridine-containing arylene ethynylene strands were connected to the 2- and 2'-positions of (R)- and (S)-1,1'-binaphthyl templates. The arylene ethynylene moieties underwent intramolecular coordination with Ag(I) or Cu(I) ion to afford enantiopure double helicates. The double-helical structure was elucidated on the basis of circular dichroic (CD) spectra. The importance of intramolecular complexation of the double strands for the helicate formation was confirmed by comparison with a ligand bearing a single strand. Connection of the strands through an ether linkage enabled a sorting out of the Cotton effect induced by double-helical arylene ethynylene moieties. The CD exciton chirality method unambiguously proved that the termini of the strands approach each other upon complexation and that the sense of the induced helicity is the same as predicted by molecular modeling.     

Association between a photo-intermediate of a M-lacking mutant D75N of pharaonis phoborhodopsin and its cognate transducer

Pharaonis phoborhodopsin (ppR or pharaonis sensory rhodopsin II) is a receptor of the negative phototaxis of Natronobacterium pharaonis and forms a complex with its transducer pHtrII in membranes. Flash-photolyis of a D75N mutant did not yield the M-intermediate, but an O-like intermediate is observed in a ms time range. We examined the interaction between the D75N of ppR and t-Htr (truncated pHtrII). These formed a complex in the presence of 0.1% n-dodecyl-beta-maltoside, and the association accelerated the decay of the O of D75N from 15 to 56 s(-1). From the decay time constants under varying ratios of D75N and t-Htr, n, the molar ratio of D75N/t-Htr in the complex, and K(D), the dissociation constant, were estimated. The value of n was unity and K(D) was estimated to 146 nM. This K(D) value can be considered to be the association between the photo-intermediate and t-Htr, which is deduced by the method of estimation. Previously we (Photochem. Photobiol. 74 (2001) 489) reported a K(D) of 15 microM for the interaction between the wild-type and t-Htr by means of the change in M-decay rates. Therefore, this value should be the K(D) value for the interaction between M of the wild-type and t-Htr.     

Design and synthesis of dual inhibitors of acetylcholinesterase and serotonin transporter targeting potential agents for Alzheimer's disease

Highly efficient acetylcholinesterase (AChE) and serotonin transporter (SERT) dual inhibitors, (S)-4 and (R)-13 were designed and synthesized on the basis of the hypothetical model of AChE active site. Both compounds showed potent inhibitory activities against AChE and SERT. [structure: see text]     

Pyrolysis reaction of carpronium chloride and its structurally related compounds. 1—electronic and steric effects on the orientation of the pyrolysis reaction

The pyrolysis reaction of carpronium chloride and its structurally related compounds, which were trimethyl-aminoalkyl acid alkyl esters involving two, three or four skeletal methylene groups, have been investigated by pyrolysis gas chromatography mass spectrometry. The results indicated that the reaction modes of these ammonium compounds were essentially dependent on the number of skeletal methylene groups, and secondarily on the length of the carbon chain of the ester group. These phenomena have been interpreted in terms of electronic and steric contributions for the ionic elimination reaction. The electronic and steric effects on the orientation of the reaction are discussed on the basis of the atomic population calculated by the CNDO/2 method.     

Perturbation Formulas for Polarization Ratio and Phase Shift of Rayleigh Waves in Prestressed Anisotropic Media

This paper completes an earlier study (Tanuma and Man, Journal of Elasticity, 85, 21–37, 2006) where we derive a first-order perturbation formula for the phase velocity of Rayleigh waves that propagate along the free surface of a macroscopically homogeneous, anisotropic, prestressed half-space. We adopt the formulation of linear elasticity with initial stress and assume that the deviation of the prestressed anisotropic medium from a suitably-chosen, comparative, unstressed and isotropic state be small. No assumption, however, is made on the material anisotropy of the incremental elasticity tensor. With the help of the Stroh formalism, here we derive first-order perturbation formulas for the changes in polarization ratio and phase shift of Rayleigh waves from their respective comparative isotropic value. Examples are given, which show that the perturbation formulas for phase velocity and polarization ratio can serve as a starting point for investigations on the possible advantages of using Rayleigh-wave polarization, as compared with using wave speed, for acoustoelastic measurement of stress.