Fast verified computation for solutions of algebraic Riccati equations arising in transport theory

A fast algorithm for enclosing the solution of the nonsymmetric algebraic Riccati equation arising in transport theory is proposed. The equation has a special structure, which is taken into account to reduce the complexity. By exploiting the structure, the enclosing process involves only quadratic complexity under a reasonable assumption. The algorithm moreover verifies the uniqueness and minimal positiveness of the enclosed solution. Numerical results show the efficiency of the algorithm.     

Adsorption equilibrium and kinetics of cesium onto insoluble Prussian blue synthesized by an immediate precipitation reaction between Fe3+ and [Fe(CN)6]4−

The adsorption equilibrium and kinetics of cesium ion (Cs⁺) onto insoluble Prussian blue (PB) prepared by an immediate precipitation reaction between Fe³⁺ and [Fe(CN)₆]^4? was investigated under initial Cs⁺ concentration of under 0.15 mmol/L. Synthesis conditions in this method were almost insensitive to the adsorption ability of insoluble PB, and this method provided one of the smallest PB crystallites among synthesis methods. Even when molar concentration of H₃O⁺ was more than 200 times higher or molar concentration of K⁺ was more than 50,000 times higher than that of Cs⁺ in the aqueous solution, the equilibrium adsorption amount was reduced by only approximately one-half to two-third of that in the pure system; that is, the insoluble PB synthesized possessed a considerably high adsorption selectivity for Cs⁺. In contrast to the excellent adsorption ability under adsorption equilibrium, adsorption rate was quite slow. It took at least 2 weeks at 25 °C to completely attain the adsorption equilibrium, even though the primary particle size (crystallite size) and secondary particle size (aggregate size of the crystallites) were sufficiently small at approximately 14 nm and 53–106 μm, respectively. This slow adsorption is primarily due to the large resistance of intracrystalline diffusion; the intracrystalline diffusion coefficient was extremely small at less than 3.3 × 10^?22 m²/s. We also found that increase in temperature could significantly decrease this diffusion resistance, resulting in much quicker elimination of Cs⁺ from the aqueous solution.     

Oxidation of disulfides with electrophilic halogenating reagents: concise methods for preparation of thiosulfonates and sulfonyl halides

The reaction of aromatic or benzylic disulfides with 2.5 equiv of Selectfluor™ in acetonitrile/water (10:1) at room temperature efficiently produced the corresponding thiosulfonates. Conversely, the reaction of disulfides with 6.5 equiv of Selectfluor™ or thiosulfonates with 4.5 equiv of Selectfluor™ in refluxing acetonitrile/water (10:1) provided sulfonyl fluorides in high yields. Accufluor™ and FP-T300™ are also effective in preparing sulfonyl fluorides from disulfides under the similar reaction conditions. Sulfonyl chlorides or sulfonyl bromides were effectively obtained from the reaction of disulfides with 6 equiv of either N-chlorosuccinimide or N-bromosuccinimide in acetonitrile/water (10:1) at room temperature. Some other electrophilic chlorinating or brominating reagents are also able to be used instead of N-chlorosuccinimide or N-bromosuccinimide for the syntheses of sulfonyl halides from disulfides. These reactions of disulfides with electrophilic halogenating reagents are convenient methods to prepare thiosulfonates and sulfonyl halides.     

Comparison of magnetic resonance concentration measurements in water to temperature measurements in compressible air flows

Magnetic resonance imaging (MRI) measurements in liquid flows provide highly detailed 3D mean velocity and concentration data in complex turbulent mixing flow applications. The scalar transport analogy is applied to infer the mean temperature distribution in high speed gas flows directly from the MRI concentration measurements in liquid. Compressibility effects on turbulent mixing are known to be weak for simple flows at high subsonic Mach number, and it was not known if this would hold in more complex flows characteristic of practical applications. Furthermore, the MRI measurements are often done at lower Reynolds number than the compressible application, although both are generally done in fully turbulent flows. The hypothesis is that the conclusions from MRI measurements performed in water are transferable to high subsonic Mach number applications. The present experiment is designed to compare stagnation temperature measurements in high speed airflow (M = 0.7) to concentration measurements in an identical water flow apparatus. The flow configuration was a low aspect ratio wall jet with a thick splitter plate producing a 3D complex downstream flow mixing the wall-jet fluid with the mainstream flow. The three-dimensional velocity field is documented using magnetic resonance velocimetry in the water experiment, and the mixing is quantified by measuring the mean concentration distribution of wall-jet fluid marked with dissolved copper sulfate. The airflow experiments are operated with a temperature difference between the main stream and the wall jet. Profiles of the stagnation temperature are measured with a shielded thermocouple probe. The results show excellent agreement between normalized temperature and concentration profiles after correction of the temperature measurements for the effects of energy separation. The agreement is within 1 % near the edges of the mixing layer, which suggests that the mixing characteristics of the large scale turbulence structures are the same in the two flows.     

Fourier Transform Infrared Spectroscopy of Skin Cancer Cells and Tissues

Abstract

The aim of this review is to combine all the information related to the characterization of skin tissues and cells, focusing on the identification of the specific biochemical characteristics of skin cancer. We have characterized two types of melanoma by FTIR spectroscopy: a murine melanoma (B16F10 cell line) and a human melanoma (C8161 cell line). The cells were deposited on IR transparent CaF₂ windows, the spectral range used lay between 900-4000 cm^{? 1}, transmission mode with 2 cm^{? 1} resolution, and 32 scans. A biochemical association is presented for all the absorption bands identified in this study. Besides the characterization of both cell lines above, a collection of works done in the area of skin cancer was also carried out, in this review; some interesting results obtained by different authors with respect to the characterization of different samples (melanomas, follicle sheath, basal cell carcinoma, epidermis tissues, dermis tissue, and human stratum corneum) are presented and compared to the chemical and biological associations performed in each case. The identification of biochemical injuries provides important information that, associated with clinical examination, can assist the diagnosis of diseases. Several FTIR techniques can be used in the diagnosis of biochemical changes in biological tissues, by identifying molecular markers associated with malignant and benign changes or variations in the composition of amino acids in tissues and cells. In the near future, a further study to compare histopatological analysis and biochemical characterization by FTIR spectroscopy would be interesting, in order to verify the accuracy and validate the applicability of this technique in the diagnosis of skin lesions from a statistical viewpoint.     

Dynamics of 15N natural abundance in wood-decomposing fungi and their ecophysiological implications

Nine species of basidiomycota and one species of ascomycota were grown in an ammonium sulphate media and on beech wood; and the general ¹⁵N dynamic patterns of the hyphae were examined. The fungal body initially became depleted in ¹⁵N in both the types of incubation. However, the underlying mechanisms were quite different, that is, significant fungal ¹⁵N drop on the beech wood is associated with the fungal N reallocation and the uptake of atmospheric ammonia and/or NO_x, in addition to isotope fractionation during assimilation. Although the ¹⁵N values of the wood-decomposing basidiocarps were generally close to the ¹⁵N values of the wood, it does not always indicate that the wood derived N was the sole N source for the fungi throughout the growth periods as shown in our wood-decomposing experiment.     

Stern-Gerlach studies of organometallic sandwich clusters

Stern-Gerlach type magnetic deflection measurements were performed for two types of multiple sandwich clusters: vanadium-benzene V_n(C₆H₆)_n+1 and terbium-cyclooctatetraene Tb_n(C₈H₈)_n+1. Beams of V_n(C₆H₆)_n+1 clusters (n = 1-4) showed symmetric broadening induced by the inhomogeneous field, indicating free spin behavior similar to that displayed by isolated paramagnetic atoms. By contrast, beams of Tb_n(C₈H₈)_n+1 clusters displayed one-sided deflection, indicating that fast spin relaxation occurs within the clusters. The difference in the magnetic deflection behavior exhibited by these two systems is explained by their electronic structures, specifically the bonding characteristics between metal atoms and ligand molecules.     

Analysis of gardenia blue in foods by thin-layer chromatography

In the present study, a thin-layer chromatography (TLC) method for the analysis of gardenia blue was described. Gardenia blue is obtained from the fruits of Gardenia augusta Merrill or Gardenia jasminoides Ellis. Recently, gardenia blue has frequently been used in Japan as a natural coloring in various foods. However, the structural characterization of gardenia blue components has not been yet clarified and even chromatographic separation of the components has not been reported. Synthetic colors in foods are generally analyzed by TLC; so, we therefore investigated the analysis of gardenia blue in foods with TLC. We established two TLC conditions; reversed phase C-18 TLC using a solvent system of aqueous 0.2% TFA–acetonitrile–ethanol (1:2:3) and TLC on cellulose plate using a solvent system consisting of acetone–3-methyl-1-butanol–water (6:5:5). Both conditions yielded three well-delineated spots with good separation. We applied these separations to the analyses of gardenia blue in coloring matter preparations from different manufacturers and in foods on the market. After the gardenia blue was extracted from the samples with water, the extract was evaporated and the residue was dissolved in water–methanol (1:1). Aliquots of the dissolved solutions were then applied to TLC and their chromatographic behaviors were observed. Each preparation showed characteristic spot patterns depending on the manufacturers. The R_f values of the separated spots when extracted from foods are slightly different from the R_f values of the spots observed for standards, and we were thus able to identify the manufacturers using the spot pattern of gardenia blue. The present study is considered to be useful for the establishment of a method of analysis for gardenia blue in coloring preparations and foods.     

Synthesis of arylallenes by palladium-catalyzed retro-propargylation of homopropargyl alcohols

Treatment of tertiary homopropargyl alcohol with aryl halide under palladium catalysis provided arylallenes regioselectively. The reaction includes retro-propargylation, which proceeds in a concerted fashion via a cyclic transition state and transfers the stereochemistry of homopropargyl alcohols through C-C bond cleavage. The present method enables the use of homopropargyl alcohols as allenylmetal equivalents.