Nonadiabatic transition in the dissociation process from inner valence states of O(2) (+)

In a previous paper we reported a study of the electronic structures of inner valence states of O(2) (+) and the dissociation process, where there remained some questions as to the origins of the dissociation fragment formation of the O+((2)D)+O((3)P) limit in observed spectra. In this paper, we present the results of calculations of the nonadiabatic transition probabilities of the multichannel dissociation process from the inner valence states of O(2) (+) and reproduce the general features of observed spectra previously reported, including fragment formation, using the Zhu-Nakamura theory.     

The maximum asymptotic bias of S-estimates for regression over the neighborhoods defined by certain special capacities

The maximum asymptotic bias of an S-estimate for regression in the linear model is evaluated over the neighborhoods (called (c,γ)-neighborhoods) defined by certain special capacities, and its lower and upper bounds are derived. As special cases, the (c,γ)-neighborhoods include those in terms of -contamination, total variation distance and Rieder's (,δ)-contamination. It is shown that when the model distribution is normal and the (,δ)-contamination neighborhood is adopted, the lower and upper bounds of an S-estimate (including the LMS-estimate) based on a jump function coincide with the maximum asymptotic bias. The tables of the maximum asymptotic bias of the LMS-estimate are given. These results are an extension of the corresponding ones due to Martin et al. (Ann. Statist. 17 (1989) 1608), who used -contamination neighborhoods.     

Multiplex amplified product-length polymorphism analysis for rapid detection of human mitochondrial DNA variations.

A number of mutations in coding and noncoding regions of mitochondrial DNA (mtDNA) have previously been studied. In the present study, we simultaneously typed six mutation sites in the coding region by use of amplified product-length polymorphism (APLP) analysis. The mtDNA variations of 2471 individuals from 20 populations of Japanese, Korean, Chinese, and German were examined and classified into 18 haplotypes. Two of these haplotypes, B1 (estimated ancestral haplotype) and C1, were distributed among all populations tested. However, the haplotypes A1, A2, B2, B3, and C2 were mostly restricted to the Mongoloid populations, whereas haplotypes B5 and C5 appeared almost exclusively in the German population. Phylogenetic analysis by the neighbor-joining method revealed that the Japanese populations were more closely related to each other than to the other East Asian populations surveyed. The multiplex APLP method is suitable for large-scale screening studies of mtDNA variability because it is both rapid and economical.     

A Strategy for Neuraminidase Inhibitors Using Mechanism‐Based Labeling Information

A potent inhibitor for Vibrio cholerae neuraminidase (VCNA) was developed by using a novel two‐step strategy, a target amino acid validation using mechanism‐based labeling information, and a potent inhibitor search using a focused library. The labeling information suggested the hidden dynamics of a loop structure of VCNA, which can be a potential target of the novel inhibitor. A focused library composed of 187 compounds was prepared from a 9‐azide derivative of 2,3‐dehydro‐N‐acetylneuraminic acid (DANA) to interrupt the function of the loop of the labeled residues. Inhibitor 3c showed potent inhibition properties and was the strongest inhibitor with FANA, a N‐trifluoroacetyl derivative of DANA. Validation studies of the inhibitor with a detergent and a Lineweaver–Burk plot suggested that the 9‐substitution group would interact hydrophobically with the target loop moiety, adding a noncompetitive inhibition property to the DANA skeleton. This information enabled us to design compound 4 having the combined structure of 3c and FANA. Compound 4 showed the most potent inhibition (K_i=73 nM , mixed inhibition) of VCNA with high selectivity among the tested viral, bacterial, and mammal neuraminidases.     

Color speckle

Speckle is a random distribution of a radiant power density or an irradiance on the observation plane (retina of observers in the laser display) due to the interference of randomly phase-modulated wavefronts. Since a color is synthesized by the superposition of red-green-blue (RGB) primary-color lasers in laser displays, if the speckle patterns of RGB lasers are uncorrelated with each other, then the fluctuation in radiant power density results in a change in color received by the observer. We name this random distribution of color “color speckle”. The distribution of color on the xy chromaticity diagram is investigated for speckle patterns of various speckle contrasts. We demonstrate a numerical simulation of color speckle. Then, we derive the theoretical expressions of the variance and covariance of the distribution of xy chromaticity under the assumption of low speckle contrast.     

Preparation and properties of silicon containing copolyamides

Copolyamides containing siloxane moieties in main chain were prepared by a melt polycondensation with 1,3-bis(3-aminopropyl)tetramethyldisiloxane (E), hexamethylenediamine (N6), and adipic acid (6). Glass transition temperature (T_g), cold crystallization temperature (T_cc), and melting temperature (T_m) were measured by differential thermal analysis (DTA). The depression of T_m for copolyamide was fitted by the Flory curve. Melting peak remarkably broadens with increasing E6 component in copolyamide. The change of T_g was fitted by the Gibbs and Dimarzio's equation in which the number of flexible bond is considered. The difference between T_g and T_cc increased with increasing E6 component. These DTA studies suggest that the crystallization of N66 component in copolyamide is hindered by the bulky siloxane moiety, while the micro-Brownian motion of amorphous segment is promoted by the flexible siloxane bond. Tensile strength and Young's modulus decreased with increasing E6 component. The solubility in various solvents increased with increasing E6 component. Permeability of oxygen and nitrogen increased with an increase of temperature and E6 component. The separation coefficient of oxygen to nitrogen rapidly increased near 50 mol% of E6 concentration and then leveled out above 70 mol%. The contact angle with water and methylene iodide increased with an introduction of the siloxane moiety into polymer chain.     

Valence states of 57Fe decayed from 57Mn implanted into KMnO4

In-beam Mössbauer spectra of ⁵⁷Fe, decayed from short-lived ⁵⁷Mn (T_1/2 = 1.45 min) implanted into potassium permanganate, KMnO₄, were measured at temperatures between 11 K and 130 K. This is the first application of a secondary RI beam to the study of valence states after nuclear transformation. The in-beam Mössbauer spectra obtained below 90 K could be analyzed with two components, a doublet and a singlet. From the calculations of the molecular orbital wave functions, the singlet is suggested to be substitutional ⁵⁷Fe atoms for Mn-sites in tetrahedral [MnO₄]^– with an unusually high valence state of Fe⁸⁺.     

Reactions of 57Mn implanted into solid oxygen

The in-beam Mössbauer spectroscopy using a short-lived ⁵⁷Mn (T _1/2=1.5 min) beam was carried out to study the production of the exotic chemical species of ⁵⁷Fe atoms arising from ⁵⁷Mn implanted into solid oxygen. The obtained spectra can be analyzed by four components of doublets at least, which are assigned to be novel Fe species of FeO, Fe(O₂), (O₂)FeO₂, and Fe(O₂)₂, on the basis of ab initio molecular orbital calculations.