Preliminary quantitative analysis of myocardial fatty acid metabolism from fluorescent X‐ray computed tomography imaging

Fluorescent X‐ray computed tomography (FXCT) using synchrotron radiation reveals the cross‐sectional distribution of specific elements in biomedical objects. The aim of this study was to investigate the feasibility of FXCT imaging to assess the myocardial metabolic state quantitatively. Hearts labelled with non‐radioactive iodine myocardial fatty acid agent 15‐p‐(iodophenyl)‐3‐methylpentadecanoic acid (BMIPP) from cardiomyopathic and normal hamsters were imaged. FXCT images were compared with optical microscope images. Myocardial fatty acid metabolism enhanced with BMIPP was clearly depicted by FXCT, which showed an almost homogeneous image for normal and a heterogeneous image for cardiomyopathic hearts. Morphological structures of the heart such as the left ventricle and myocardial wall were also visualized by FXCT. Optical microscopy showed no fibrosis in normal and slight interstitial fibrosis in cardiomyopathic hearts. In the case of cardiomyopathy, the area of significantly reduced BMIPP uptake was 39% in the short axis of the mid‐left ventricle in the FXCT image, whereas a slight interstitial fibrosis of around 12% was recognized by optical microscopy for the same slice. This result indicated that reduced BMIPP uptake was caused by the myocardial fatty acid metabolic abnormality, not by the fibrosis in cardiomyopathy. Thus, FXCT images might be used to assess the quantitative metabolic analysis in small animal models of heart diseases.     

Hydrogen storage properties of isocyanide-stabilized palladium nanoparticles

Monodispersed palladium nanoparticles protected with n-octyl isocyanide were prepared, and their hydrogen absorption behavior was evaluated. The formation of the nanoparticles has been confirmed by means of 1H NMR and elemental analysis. Fourier transform infrared (FT-IR) showed that three distinct bands (2156, 1964, and 1611 cm(-1)) assigned to mono-, double-, and triple-bridged isocyanide ligands on the palladium surface. The average diameter of the particles was estimated to be 2.1 +/- 0.7 nm from observation by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) analysis revealed that the particles contained Pd(0) with little amounts of Pd(II) or Pd(IV), in sharp contrast to the thiol- or phosphine-stabilized palladium nanoparticles. The absorption and desorption of hydrogen were reversible, and the reactions were much faster for the nanoparticles than for the bulk palladium metal, whereas the storage capacity was almost the same, 0.6 wt %.     

Strained polycycles by H5C5x free-radical cascades

[reaction: see text] An H(5)C(5x)-type free-radical chain reaction selectively generates up to three new bonds and three new stereocenters in one pot. This previously unexploited strategy provides a straightforward route to the tricyclic cyclopenta[c]indene skeleton, present in a wide range of pharmacologically active natural products, and can significantly simplify the synthesis of other strained polycyclic structures by sidestepping protection, deprotection, and functional group interconversion steps.     

Crystallization of titania ultra-fine particles from peroxotitanic acid in aqueous solution in the present of polymer and incorporation into poly(methyl methacylate) via dispersion in organic solvent

We report a novel strategy for incorporation of titanium dioxide (TiO₂) particles, which were crystallized from peroxotitanic acid in the presence of hydrophilic polymer by hydrothermal treatment in aqueous solution, into poly(methyl methacrylate) (PMMA) via dispersion into chloroform. Dispersion of TiO₂ particles into chloroform was achieved by solvent change from water to chloroform in aid of amphiphilic polymer dispersant, poly(N-vinyl pyrrolidone) (PVP), poly(N-vinyl pyrrolidone-co-methyl methacrylate) (PVP-co-PMMA), poly(N-vinyl pyrrolidone-block-methyl methacrylate) (PVP-b-PMMA) through azeotropical removal of water. Incorporation of TiO₂ particles into PMMA was carried out by a casting process of a mixture of TiO₂ particles dispersed with PVP₁₅₄-b-PMMA₁₅₆ in chloroform and PMMA on a glass substrate. Resultant hybrid film containing TiO₂ less than 10 wt.% showed high transparency in visible region attributable to homogeneous dispersion into PMMA matrix. The refractive index of the hybrid films increased with TiO₂ content and agreed with the calculated values.     

3nπ* spectra of benzaldehyde. I. Vapor phosphorescence

Vibrational analysis of the vapor ³nπ* phosphorescence for three isotopic benzaldehydes (B-h₆, B-1d₁, B-Rd₅) shows that the out-of-plane aldehyde hydrogen wagging vibration (ν₂₆) is the most active non-totally symmetric mode in the spectrum. Since the intensity of 26₂⁰ ? 26₁⁰ the mechanism of ν₂₆ activity is primarily as a Franck—Condon mode. The only other out-of-plane mode definitely attributed to the vapor phosphorescence is the weakly active CHO torsional vibration (ν₃₆) with I (36₁⁰) > I (26₁⁰). Other Franck—Condon modes are ν₇, ν₂₅, ν₂₀, ν₁₇ and ν₈.     

(2,3)-Wittig sigmatropic rearrangements in steroid synthesis. New stereocontrolled approach to steroidal side chains at C-20

A new method which is based on (2-3)-Wittig sigmatropic rearrangements for the stereocontrolled synthesis of functionalized three-carbon side chains on the basic tetracyclic steroidal system is described.     

Amperometric determination of acetic acid with immobilized Trichosporon brassicae

A microbial sensor consisting of immobilized Trichosporon brassicae, a gas-permeable Teflon membrane and an oxygen electrode is suitable for the continuous determination of acetic acid in fermentation broths. When an acetic acid solution is pumped through the flow system, the current decreases to a steady state with a response time of 8 min; shorter pumping times give peaks which can also be measured. The relationship between the current decrease and the acetic acid concentration is linear up to 54 mg l^-1, with a relative standard deviation of about 6% at the higher concentrations. Selectivity is satisfactory. Results obtained with this sensor and by gas chromatography for a glutamic acid fermentation broth were in good agreement (regression coefficient 1.04). The sensor was stable for more than 3 weeks and 1500 assays.